Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-f_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull file->f_path constification from Al Viro:
"Only one thing was modifying ->f_path of an opened file - acct(2).
Massaging that away and constifying a bunch of struct path * arguments
in functions that might be given &file->f_path ends up with the
situation where we can turn ->f_path into an anon union of const
struct path f_path and struct path __f_path, the latter modified only
in a few places in fs/{file_table,open,namei}.c, all for struct file
instances that are yet to be opened"
* tag 'pull-f_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (23 commits)
Have cc(1) catch attempts to modify ->f_path
kernel/acct.c: saner struct file treatment
configfs:get_target() - release path as soon as we grab configfs_item reference
apparmor/af_unix: constify struct path * arguments
ovl_is_real_file: constify realpath argument
ovl_sync_file(): constify path argument
ovl_lower_dir(): constify path argument
ovl_get_verity_digest(): constify path argument
ovl_validate_verity(): constify {meta,data}path arguments
ovl_ensure_verity_loaded(): constify datapath argument
ksmbd_vfs_set_init_posix_acl(): constify path argument
ksmbd_vfs_inherit_posix_acl(): constify path argument
ksmbd_vfs_kern_path_unlock(): constify path argument
ksmbd_vfs_path_lookup_locked(): root_share_path can be const struct path *
check_export(): constify path argument
export_operations->open(): constify path argument
rqst_exp_get_by_name(): constify path argument
nfs: constify path argument of __vfs_getattr()
bpf...d_path(): constify path argument
done_path_create(): constify path argument
...
change on vfs_parse_fs_string() calling conventions - get rid of
the length argument (almost all callers pass strlen() of the
string argument there), add vfs_parse_fs_qstr() for the cases
that do want separate length
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-fs_context' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fs_context updates from Al Viro:
"Change vfs_parse_fs_string() calling conventions
Get rid of the length argument (almost all callers pass strlen() of
the string argument there), add vfs_parse_fs_qstr() for the cases that
do want separate length"
* tag 'pull-fs_context' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
do_nfs4_mount(): switch to vfs_parse_fs_string()
change the calling conventions for vfs_parse_fs_string()
When s_start() fails to allocate memory for set_event_iter, it returns NULL
before acquiring event_mutex. However, the corresponding s_stop() function
always tries to unlock the mutex, causing a lock imbalance warning:
WARNING: bad unlock balance detected!
6.17.0-rc7-00175-g2b2e0c04f78c #7 Not tainted
-------------------------------------
syz.0.85611/376514 is trying to release lock (event_mutex) at:
[<ffffffff8dafc7a4>] traverse.part.0.constprop.0+0x2c4/0x650 fs/seq_file.c:131
but there are no more locks to release!
The issue was introduced by commit b355247df1 ("tracing: Cache ':mod:'
events for modules not loaded yet") which added the kzalloc() allocation before
the mutex lock, creating a path where s_start() could return without locking
the mutex while s_stop() would still try to unlock it.
Fix this by unconditionally acquiring the mutex immediately after allocation,
regardless of whether the allocation succeeded.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250929113238.3722055-1-sashal@kernel.org
Fixes: b355247df1 ("tracing: Cache ":mod:" events for modules not loaded yet")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Merge tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Support pulling non-linear xdp data with bpf_xdp_pull_data() kfunc
(Amery Hung)
Applied as a stable branch in bpf-next and net-next trees.
- Support reading skb metadata via bpf_dynptr (Jakub Sitnicki)
Also a stable branch in bpf-next and net-next trees.
- Enforce expected_attach_type for tailcall compatibility (Daniel
Borkmann)
- Replace path-sensitive with path-insensitive live stack analysis in
the verifier (Eduard Zingerman)
This is a significant change in the verification logic. More details,
motivation, long term plans are in the cover letter/merge commit.
- Support signed BPF programs (KP Singh)
This is another major feature that took years to materialize.
Algorithm details are in the cover letter/marge commit
- Add support for may_goto instruction to s390 JIT (Ilya Leoshkevich)
- Add support for may_goto instruction to arm64 JIT (Puranjay Mohan)
- Fix USDT SIB argument handling in libbpf (Jiawei Zhao)
- Allow uprobe-bpf program to change context registers (Jiri Olsa)
- Support signed loads from BPF arena (Kumar Kartikeya Dwivedi and
Puranjay Mohan)
- Allow access to union arguments in tracing programs (Leon Hwang)
- Optimize rcu_read_lock() + migrate_disable() combination where it's
used in BPF subsystem (Menglong Dong)
- Introduce bpf_task_work_schedule*() kfuncs to schedule deferred
execution of BPF callback in the context of a specific task using the
kernel’s task_work infrastructure (Mykyta Yatsenko)
- Enforce RCU protection for KF_RCU_PROTECTED kfuncs (Kumar Kartikeya
Dwivedi)
- Add stress test for rqspinlock in NMI (Kumar Kartikeya Dwivedi)
- Improve the precision of tnum multiplier verifier operation
(Nandakumar Edamana)
- Use tnums to improve is_branch_taken() logic (Paul Chaignon)
- Add support for atomic operations in arena in riscv JIT (Pu Lehui)
- Report arena faults to BPF error stream (Puranjay Mohan)
- Search for tracefs at /sys/kernel/tracing first in bpftool (Quentin
Monnet)
- Add bpf_strcasecmp() kfunc (Rong Tao)
- Support lookup_and_delete_elem command in BPF_MAP_STACK_TRACE (Tao
Chen)
* tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (197 commits)
libbpf: Replace AF_ALG with open coded SHA-256
selftests/bpf: Add stress test for rqspinlock in NMI
selftests/bpf: Add test case for different expected_attach_type
bpf: Enforce expected_attach_type for tailcall compatibility
bpftool: Remove duplicate string.h header
bpf: Remove duplicate crypto/sha2.h header
libbpf: Fix error when st-prefix_ops and ops from differ btf
selftests/bpf: Test changing packet data from kfunc
selftests/bpf: Add stacktrace map lookup_and_delete_elem test case
selftests/bpf: Refactor stacktrace_map case with skeleton
bpf: Add lookup_and_delete_elem for BPF_MAP_STACK_TRACE
selftests/bpf: Fix flaky bpf_cookie selftest
selftests/bpf: Test changing packet data from global functions with a kfunc
bpf: Emit struct bpf_xdp_sock type in vmlinux BTF
selftests/bpf: Task_work selftest cleanup fixes
MAINTAINERS: Delete inactive maintainers from AF_XDP
bpf: Mark kfuncs as __noclone
selftests/bpf: Add kprobe multi write ctx attach test
selftests/bpf: Add kprobe write ctx attach test
selftests/bpf: Add uprobe context ip register change test
...
A soft lockup was observed when loading amdgpu module.
If a module has a lot of tracable functions, multiple calls
to kallsyms_lookup can spend too much time in RCU critical
section and with disabled preemption, causing kernel panic.
This is the same issue that was fixed in
commit d0b24b4e91 ("ftrace: Prevent RCU stall on PREEMPT_VOLUNTARY
kernels") and commit 42ea22e754 ("ftrace: Add cond_resched() to
ftrace_graph_set_hash()").
Fix it the same way by adding cond_resched() in ftrace_module_enable.
Link: https://lore.kernel.org/aMQD9_lxYmphT-up@vova-pc
Signed-off-by: Vladimir Riabchun <ferr.lambarginio@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Fix buffer overflow in osnoise_cpu_write()
The allocated buffer to read user space did not add a nul terminating byte
after copying from user the string. It then reads the string, and if user
space did not add a nul byte, the read will continue beyond the string.
Add a nul terminating byte after reading the string.
- Fix missing check for lockdown on tracing
There's a path from kprobe events or uprobe events that can update the
tracing system even if lockdown on tracing is activate. Add a check in the
dynamic event path.
- Add a recursion check for the function graph return path
Now that fprobes can hook to the function graph tracer and call different
code between the entry and the exit, the exit code may now call functions
that are not called in entry. This means that the exit handler can possibly
trigger recursion that is not caught and cause the system to crash.
Add the same recursion checks in the function exit handler as exists in the
entry handler path.
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Merge tag 'trace-v6.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix buffer overflow in osnoise_cpu_write()
The allocated buffer to read user space did not add a nul terminating
byte after copying from user the string. It then reads the string,
and if user space did not add a nul byte, the read will continue
beyond the string.
Add a nul terminating byte after reading the string.
- Fix missing check for lockdown on tracing
There's a path from kprobe events or uprobe events that can update
the tracing system even if lockdown on tracing is activate. Add a
check in the dynamic event path.
- Add a recursion check for the function graph return path
Now that fprobes can hook to the function graph tracer and call
different code between the entry and the exit, the exit code may now
call functions that are not called in entry. This means that the exit
handler can possibly trigger recursion that is not caught and cause
the system to crash.
Add the same recursion checks in the function exit handler as exists
in the entry handler path.
* tag 'trace-v6.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: fgraph: Protect return handler from recursion loop
tracing: dynevent: Add a missing lockdown check on dynevent
tracing/osnoise: Fix slab-out-of-bounds in _parse_integer_limit()
function_graph_enter_regs() prevents itself from recursion by
ftrace_test_recursion_trylock(), but __ftrace_return_to_handler(),
which is called at the exit, does not prevent such recursion.
Therefore, while it can prevent recursive calls from
fgraph_ops::entryfunc(), it is not able to prevent recursive calls
to fgraph from fgraph_ops::retfunc(), resulting in a recursive loop.
This can lead an unexpected recursion bug reported by Menglong.
is_endbr() is called in __ftrace_return_to_handler -> fprobe_return
-> kprobe_multi_link_exit_handler -> is_endbr.
To fix this issue, acquire ftrace_test_recursion_trylock() in the
__ftrace_return_to_handler() after unwind the shadow stack to mark
this section must prevent recursive call of fgraph inside user-defined
fgraph_ops::retfunc().
This is essentially a fix to commit 4346ba1604 ("fprobe: Rewrite
fprobe on function-graph tracer"), because before that fgraph was
only used from the function graph tracer. Fprobe allowed user to run
any callbacks from fgraph after that commit.
Reported-by: Menglong Dong <menglong8.dong@gmail.com>
Closes: https://lore.kernel.org/all/20250918120939.1706585-1-dongml2@chinatelecom.cn/
Fixes: 4346ba1604 ("fprobe: Rewrite fprobe on function-graph tracer")
Cc: stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/175852292275.307379.9040117316112640553.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Menglong Dong <menglong8.dong@gmail.com>
Acked-by: Menglong Dong <menglong8.dong@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- fprobe: Even if there is a memory allocation failure, try to remove
the addresses recorded until then from the filter. Previously we
just skip it.
- tracing: dynevent: Add a missing lockdown check on dynevent. This
dynevent is the interface for all probe events. Thus if there is no
check, any probe events can be added after lock down the tracefs.
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Merge tag 'probes-fixes-v6.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fixes from Masami Hiramatsu:
- fprobe: Even if there is a memory allocation failure, try to remove
the addresses recorded until then from the filter. Previously we just
skipped it.
- tracing: dynevent: Add a missing lockdown check on dynevent. This
dynevent is the interface for all probe events. Thus if there is no
check, any probe events can be added after lock down the tracefs.
* tag 'probes-fixes-v6.17-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: dynevent: Add a missing lockdown check on dynevent
tracing: fprobe: Fix to remove recorded module addresses from filter
Even if there is a memory allocation failure in fprobe_addr_list_add(),
there is a partial list of module addresses. So remove the recorded
addresses from filter if exists.
This also removes the redundant ret local variable.
Fixes: a3dc2983ca ("tracing: fprobe: Cleanup fprobe hash when module unloading")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Reviewed-by: Menglong Dong <menglong8.dong@gmail.com>
Currently uprobe (BPF_PROG_TYPE_KPROBE) program can't write to the
context registers data. While this makes sense for kprobe attachments,
for uprobe attachment it might make sense to be able to change user
space registers to alter application execution.
Since uprobe and kprobe programs share the same type (BPF_PROG_TYPE_KPROBE),
we can't deny write access to context during the program load. We need
to check on it during program attachment to see if it's going to be
kprobe or uprobe.
Storing the program's write attempt to context and checking on it
during the attachment.
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20250916215301.664963-2-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since dynamic_events interface on tracefs is compatible with
kprobe_events and uprobe_events, it should also check the lockdown
status and reject if it is set.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/175824455687.45175.3734166065458520748.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When config osnoise cpus by write() syscall, the following KASAN splat may
be observed:
BUG: KASAN: slab-out-of-bounds in _parse_integer_limit+0x103/0x130
Read of size 1 at addr ffff88810121e3a1 by task test/447
CPU: 1 UID: 0 PID: 447 Comm: test Not tainted 6.17.0-rc6-dirty #288 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x55/0x70
print_report+0xcb/0x610
kasan_report+0xb8/0xf0
_parse_integer_limit+0x103/0x130
bitmap_parselist+0x16d/0x6f0
osnoise_cpus_write+0x116/0x2d0
vfs_write+0x21e/0xcc0
ksys_write+0xee/0x1c0
do_syscall_64+0xa8/0x2a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
This issue can be reproduced by below code:
const char *cpulist = "1";
int fd=open("/sys/kernel/debug/tracing/osnoise/cpus", O_WRONLY);
write(fd, cpulist, strlen(cpulist));
Function bitmap_parselist() was called to parse cpulist, it require that
the parameter 'buf' must be terminated with a '\0' or '\n'. Fix this issue
by adding a '\0' to 'buf' in osnoise_cpus_write().
Cc: <mhiramat@kernel.org>
Cc: <mathieu.desnoyers@efficios.com>
Cc: <tglozar@redhat.com>
Link: https://lore.kernel.org/20250916063948.3154627-1-wangliang74@huawei.com
Fixes: 17f89102fe ("tracing/osnoise: Allow arbitrarily long CPU string")
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
system_wq is a per-CPU worqueue, yet nothing in its name tells about that
CPU affinity constraint, which is very often not required by users. Make
it clear by adding a system_percpu_wq.
queue_work() / queue_delayed_work() mod_delayed_work() will now use the
new per-cpu wq: whether the user still stick on the old name a warn will
be printed along a wq redirect to the new one.
This patch add the new system_percpu_wq except for mm, fs and net
subsystem, whom are handled in separated patches.
The old wq will be kept for a few release cylces.
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/20250905091040.109772-2-marco.crivellari@suse.com
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Replace the opencoded for_each_cpu(cpu, cpu_online_mask) loop with the
more readable and equivalent for_each_online_cpu(cpu) macro.
Link: https://lore.kernel.org/20250811064158.2456-1-wangfushuai@baidu.com
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Currently the syscall trace events show each value as hexadecimal, but
without adding "0x" it can be confusing:
sys_write(fd: 4, buf: 0x55c4a1fa9270, count: 44)
Looks like the above write wrote 44 bytes, when in reality it wrote 68
bytes.
Add a "0x" for all values greater or equal to 10 to remove the ambiguity.
For values less than 10, leave off the "0x" as that just adds noise to the
output.
Also change the iterator to check if "i" is nonzero and print the ", "
delimiter at the start, then adding the logic to the trace_seq_printf() at
the end.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Takaya Saeki <takayas@google.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Link: https://lore.kernel.org/20250923130713.764558957@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The syscall events are pseudo events that hook to the raw syscalls. The
ftrace_syscall_enter/exit() callback is called by the raw_syscall
enter/exit tracepoints respectively whenever any of the syscall events are
enabled.
The trace_array has an array of syscall "files" that correspond to the
system calls based on their __NR_SYSCALL number. The array is read and if
there's a pointer to a trace_event_file then it is considered enabled and
if it is NULL that syscall event is considered disabled.
Currently it uses an rcu_dereference_sched() to get this pointer and a
rcu_assign_ptr() or RCU_INIT_POINTER() to write to it. This is unnecessary
as the file pointer will not go away outside the synchronization of the
tracepoint logic itself. And this code adds no extra RCU synchronization
that uses this.
Replace these functions with a simple READ_ONCE() and WRITE_ONCE() which
is all they need. This will also allow this code to not depend on
preemption being disabled as system call tracepoints are now allowed to
fault.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Takaya Saeki <takayas@google.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Link: https://lore.kernel.org/20250923130713.594320290@kernel.org
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
No functional changes, except for the addition of the headers for the
kfuncs so that they can be used for signature verification.
Signed-off-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20250914215141.15144-8-kpsingh@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
- Fix build in some RISC-V flavours
Some system calls only are available for the 64bit RISC-V machines.
#ifdef out the cases of clock_nanosleep and futex in the sleep monitor
if they are not supported by the architecture.
- Fix wrong cast, obsolete after refactoring
Use container_of() to get to the rv_monitor structure from the
enable_monitors_next() 'p' pointer. The assignment worked only because
the list field used happened to be the first field of the structure.
- Remove redundant include files
Some include files were listed twice. Remove the extra ones and sort
the includes.
- Fix missing unlock on failure
There was an error path that exited the rv_register_monitor() function
without releasing a lock. Change that to goto the lock release.
- Add Gabriele Monaco to be Runtime Verifier maintainer
Gabriele is doing most of the work on RV as well as collecting patches.
Add him to the maintainers file for Runtime Verification.
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Merge tag 'trace-rv-v6.17-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull runtime verifier fixes from Steven Rostedt:
- Fix build in some RISC-V flavours
Some system calls only are available for the 64bit RISC-V machines.
#ifdef out the cases of clock_nanosleep and futex in the sleep
monitor if they are not supported by the architecture.
- Fix wrong cast, obsolete after refactoring
Use container_of() to get to the rv_monitor structure from the
enable_monitors_next() 'p' pointer. The assignment worked only
because the list field used happened to be the first field of the
structure.
- Remove redundant include files
Some include files were listed twice. Remove the extra ones and sort
the includes.
- Fix missing unlock on failure
There was an error path that exited the rv_register_monitor()
function without releasing a lock. Change that to goto the lock
release.
- Add Gabriele Monaco to be Runtime Verifier maintainer
Gabriele is doing most of the work on RV as well as collecting
patches. Add him to the maintainers file for Runtime Verification.
* tag 'trace-rv-v6.17-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
rv: Add Gabriele Monaco as maintainer for Runtime Verification
rv: Fix missing mutex unlock in rv_register_monitor()
include/linux/rv.h: remove redundant include file
rv: Fix wrong type cast in enabled_monitors_next()
rv: Support systems with time64-only syscalls
If create_monitor_dir() fails, the function returns directly without
releasing rv_interface_lock. This leaves the mutex locked and causes
subsequent monitor registration attempts to deadlock.
Fix it by making the error path jump to out_unlock, ensuring that the
mutex is always released before returning.
Fixes: 24cbfe18d5 ("rv: Merge struct rv_monitor_def into struct rv_monitor")
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20250903065112.1878330-1-zhen.ni@easystack.cn
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Argument 'p' of enabled_monitors_next() is not a pointer to struct
rv_monitor, it is actually a pointer to the list_head inside struct
rv_monitor. Therefore it is wrong to cast 'p' to struct rv_monitor *.
This wrong type cast has been there since the beginning. But it still
worked because the list_head was the first field in struct rv_monitor_def.
This is no longer true since commit 24cbfe18d5 ("rv: Merge struct
rv_monitor_def into struct rv_monitor") moved the list_head, and this wrong
type cast became a functional problem.
Properly use container_of() instead.
Fixes: 24cbfe18d5 ("rv: Merge struct rv_monitor_def into struct rv_monitor")
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/20250806120911.989365-1-namcao@linutronix.de
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Syzkaller trigger a fault injection warning:
WARNING: CPU: 1 PID: 12326 at tracepoint_add_func+0xbfc/0xeb0
Modules linked in:
CPU: 1 UID: 0 PID: 12326 Comm: syz.6.10325 Tainted: G U 6.14.0-rc5-syzkaller #0
Tainted: [U]=USER
Hardware name: Google Compute Engine/Google Compute Engine
RIP: 0010:tracepoint_add_func+0xbfc/0xeb0 kernel/tracepoint.c:294
Code: 09 fe ff 90 0f 0b 90 0f b6 74 24 43 31 ff 41 bc ea ff ff ff
RSP: 0018:ffffc9000414fb48 EFLAGS: 00010283
RAX: 00000000000012a1 RBX: ffffffff8e240ae0 RCX: ffffc90014b78000
RDX: 0000000000080000 RSI: ffffffff81bbd78b RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffffffffffffffef
R13: 0000000000000000 R14: dffffc0000000000 R15: ffffffff81c264f0
FS: 00007f27217f66c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e80dff8 CR3: 00000000268f8000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
tracepoint_probe_register_prio+0xc0/0x110 kernel/tracepoint.c:464
register_trace_prio_sched_switch include/trace/events/sched.h:222 [inline]
register_pid_events kernel/trace/trace_events.c:2354 [inline]
event_pid_write.isra.0+0x439/0x7a0 kernel/trace/trace_events.c:2425
vfs_write+0x24c/0x1150 fs/read_write.c:677
ksys_write+0x12b/0x250 fs/read_write.c:731
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
We can reproduce the warning by following the steps below:
1. echo 8 >> set_event_notrace_pid. Let tr->filtered_pids owns one pid
and register sched_switch tracepoint.
2. echo ' ' >> set_event_pid, and perform fault injection during chunk
allocation of trace_pid_list_alloc. Let pid_list with no pid and
assign to tr->filtered_pids.
3. echo ' ' >> set_event_pid. Let pid_list is NULL and assign to
tr->filtered_pids.
4. echo 9 >> set_event_pid, will trigger the double register
sched_switch tracepoint warning.
The reason is that syzkaller injects a fault into the chunk allocation
in trace_pid_list_alloc, causing a failure in trace_pid_list_set, which
may trigger double register of the same tracepoint. This only occurs
when the system is about to crash, but to suppress this warning, let's
add failure handling logic to trace_pid_list_set.
Link: https://lore.kernel.org/20250908024658.2390398-1-pulehui@huaweicloud.com
Fixes: 8d6e90983a ("tracing: Create a sparse bitmask for pid filtering")
Reported-by: syzbot+161412ccaeff20ce4dde@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/67cb890e.050a0220.d8275.022e.GAE@google.com
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
A crash was observed with the following output:
BUG: kernel NULL pointer dereference, address: 0000000000000010
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 2 UID: 0 PID: 92 Comm: osnoise_cpus Not tainted 6.17.0-rc4-00201-gd69eb204c255 #138 PREEMPT(voluntary)
RIP: 0010:bitmap_parselist+0x53/0x3e0
Call Trace:
<TASK>
osnoise_cpus_write+0x7a/0x190
vfs_write+0xf8/0x410
? do_sys_openat2+0x88/0xd0
ksys_write+0x60/0xd0
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
This issue can be reproduced by below code:
fd=open("/sys/kernel/debug/tracing/osnoise/cpus", O_WRONLY);
write(fd, "0-2", 0);
When user pass 'count=0' to osnoise_cpus_write(), kmalloc() will return
ZERO_SIZE_PTR (16) and cpulist_parse() treat it as a normal value, which
trigger the null pointer dereference. Add check for the parameter 'count'.
Cc: <mhiramat@kernel.org>
Cc: <mathieu.desnoyers@efficios.com>
Cc: <tglozar@redhat.com>
Link: https://lore.kernel.org/20250906035610.3880282-1-wangliang74@huawei.com
Fixes: 17f89102fe ("tracing/osnoise: Allow arbitrarily long CPU string")
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Commit edede7a6dc ("trace/fgraph: Fix the warning caused by missing
unregister notifier") added a call to unregister the PM notifier if
register_ftrace_graph() failed. It does so unconditionally. However,
the PM notifier is only registered with the first call to
register_ftrace_graph(). If the first registration was successful and
a subsequent registration failed, the notifier is now unregistered even
if ftrace graphs are still registered.
Fix the problem by only unregistering the PM notifier during error handling
if there are no active fgraph registrations.
Fixes: edede7a6dc ("trace/fgraph: Fix the warning caused by missing unregister notifier")
Closes: https://lore.kernel.org/all/63b0ba5a-a928-438e-84f9-93028dd72e54@roeck-us.net/
Cc: Ye Weihua <yeweihua4@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250906050618.2634078-1-linux@roeck-us.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Absolute majority of callers are passing the 4th argument equal to
strlen() of the 3rd one.
Drop the v_size argument, add vfs_parse_fs_qstr() for the cases that
want independent length.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Both tracing_mark_write and tracing_mark_raw_write call
__copy_from_user_inatomic during preempt_disable. But in some case,
__copy_from_user_inatomic may trigger page fault, and will call schedule()
subtly. And if a task is migrated to other cpu, the following warning will
be trigger:
if (RB_WARN_ON(cpu_buffer,
!local_read(&cpu_buffer->committing)))
An example can illustrate this issue:
process flow CPU
---------------------------------------------------------------------
tracing_mark_raw_write(): cpu:0
...
ring_buffer_lock_reserve(): cpu:0
...
cpu = raw_smp_processor_id() cpu:0
cpu_buffer = buffer->buffers[cpu] cpu:0
...
...
__copy_from_user_inatomic(): cpu:0
...
# page fault
do_mem_abort(): cpu:0
...
# Call schedule
schedule() cpu:0
...
# the task schedule to cpu1
__buffer_unlock_commit(): cpu:1
...
ring_buffer_unlock_commit(): cpu:1
...
cpu = raw_smp_processor_id() cpu:1
cpu_buffer = buffer->buffers[cpu] cpu:1
As shown above, the process will acquire cpuid twice and the return values
are not the same.
To fix this problem using copy_from_user_nofault instead of
__copy_from_user_inatomic, as the former performs 'access_ok' before
copying.
Link: https://lore.kernel.org/20250819105152.2766363-1-luogengkun@huaweicloud.com
Fixes: 656c7f0d2d ("tracing: Replace kmap with copy_from_user() in trace_marker writing")
Signed-off-by: Luo Gengkun <luogengkun@huaweicloud.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Commit 16f5dfbc85 ("gfp: include __GFP_NOWARN in GFP_NOWAIT")
made GFP_NOWAIT implicitly include __GFP_NOWARN.
Therefore, explicit __GFP_NOWARN combined with GFP_NOWAIT
(e.g., `GFP_NOWAIT | __GFP_NOWARN`) is now redundant. Let's clean
up these redundant flags across subsystems.
No functional changes.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250805023630.335719-1-rongqianfeng@vivo.com
Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Fix rtla and latency tooling pkg-config errors
If libtraceevent and libtracefs is installed, but their corresponding '.pc'
files are not installed, it reports that the libraries are missing and
confuses the developer. Instead, report that the pkg-config files are
missing and should be installed.
- Fix overflow bug of the parser in trace_get_user()
trace_get_user() uses the parsing functions to parse the user space strings.
If the parser fails due to incorrect processing, it doesn't terminate the
buffer with a nul byte. Add a "failed" flag to the parser that gets set when
parsing fails and is used to know if the buffer is fine to use or not.
- Remove a semicolon that was at an end of a comment line
- Fix register_ftrace_graph() to unregister the pm notifier on error
The register_ftrace_graph() registers a pm notifier but there's an error
path that can exit the function without unregistering it. Since the function
returns an error, it will never be unregistered.
- Allocate and copy ftrace hash for reader of ftrace filter files
When the set_ftrace_filter or set_ftrace_notrace files are open for read,
an iterator is created and sets its hash pointer to the associated hash that
represents filtering or notrace filtering to it. The issue is that the hash
it points to can change while the iteration is happening. All the locking
used to access the tracer's hashes are released which means those hashes can
change or even be freed. Using the hash pointed to by the iterator can cause
UAF bugs or similar.
Have the read of these files allocate and copy the corresponding hashes and
use that as that will keep them the same while the iterator is open. This
also simplifies the code as opening it for write already does an allocate
and copy, and now that the read is doing the same, there's no need to check
which way it was opened on the release of the file, and the iterator hash
can always be freed.
- Fix function graph to copy args into temp storage
The output of the function graph tracer shows both the entry and the exit of
a function. When the exit is right after the entry, it combines the two
events into one with the output of "function();", instead of showing:
function() {
}
In order to do this, the iterator descriptor that reads the events includes
storage that saves the entry event while it peaks at the next event in
the ring buffer. The peek can free the entry event so the iterator must
store the information to use it after the peek.
With the addition of function graph tracer recording the args, where the
args are a dynamic array in the entry event, the temp storage does not save
them. This causes the args to be corrupted or even cause a read of unsafe
memory.
Add space to save the args in the temp storage of the iterator.
- Fix race between ftrace_dump and reading trace_pipe
ftrace_dump() is used when a crash occurs where the ftrace buffer will be
printed to the console. But it can also be triggered by sysrq-z. If a
sysrq-z is triggered while a task is reading trace_pipe it can cause a race
in the ftrace_dump() where it checks if the buffer has content, then it
checks if the next event is available, and then prints the output
(regardless if the next event was available or not). Reading trace_pipe
at the same time can cause it to not be available, and this triggers a
WARN_ON in the print. Move the printing into the check if the next event
exists or not.
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Merge tag 'trace-v6.17-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix rtla and latency tooling pkg-config errors
If libtraceevent and libtracefs is installed, but their corresponding
'.pc' files are not installed, it reports that the libraries are
missing and confuses the developer. Instead, report that the
pkg-config files are missing and should be installed.
- Fix overflow bug of the parser in trace_get_user()
trace_get_user() uses the parsing functions to parse the user space
strings. If the parser fails due to incorrect processing, it doesn't
terminate the buffer with a nul byte. Add a "failed" flag to the
parser that gets set when parsing fails and is used to know if the
buffer is fine to use or not.
- Remove a semicolon that was at an end of a comment line
- Fix register_ftrace_graph() to unregister the pm notifier on error
The register_ftrace_graph() registers a pm notifier but there's an
error path that can exit the function without unregistering it. Since
the function returns an error, it will never be unregistered.
- Allocate and copy ftrace hash for reader of ftrace filter files
When the set_ftrace_filter or set_ftrace_notrace files are open for
read, an iterator is created and sets its hash pointer to the
associated hash that represents filtering or notrace filtering to it.
The issue is that the hash it points to can change while the
iteration is happening. All the locking used to access the tracer's
hashes are released which means those hashes can change or even be
freed. Using the hash pointed to by the iterator can cause UAF bugs
or similar.
Have the read of these files allocate and copy the corresponding
hashes and use that as that will keep them the same while the
iterator is open. This also simplifies the code as opening it for
write already does an allocate and copy, and now that the read is
doing the same, there's no need to check which way it was opened on
the release of the file, and the iterator hash can always be freed.
- Fix function graph to copy args into temp storage
The output of the function graph tracer shows both the entry and the
exit of a function. When the exit is right after the entry, it
combines the two events into one with the output of "function();",
instead of showing:
function() {
}
In order to do this, the iterator descriptor that reads the events
includes storage that saves the entry event while it peaks at the
next event in the ring buffer. The peek can free the entry event so
the iterator must store the information to use it after the peek.
With the addition of function graph tracer recording the args, where
the args are a dynamic array in the entry event, the temp storage
does not save them. This causes the args to be corrupted or even
cause a read of unsafe memory.
Add space to save the args in the temp storage of the iterator.
- Fix race between ftrace_dump and reading trace_pipe
ftrace_dump() is used when a crash occurs where the ftrace buffer
will be printed to the console. But it can also be triggered by
sysrq-z. If a sysrq-z is triggered while a task is reading trace_pipe
it can cause a race in the ftrace_dump() where it checks if the
buffer has content, then it checks if the next event is available,
and then prints the output (regardless if the next event was
available or not). Reading trace_pipe at the same time can cause it
to not be available, and this triggers a WARN_ON in the print. Move
the printing into the check if the next event exists or not
* tag 'trace-v6.17-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ftrace: Also allocate and copy hash for reading of filter files
ftrace: Fix potential warning in trace_printk_seq during ftrace_dump
fgraph: Copy args in intermediate storage with entry
trace/fgraph: Fix the warning caused by missing unregister notifier
ring-buffer: Remove redundant semicolons
tracing: Limit access to parser->buffer when trace_get_user failed
rtla: Check pkg-config install
tools/latency-collector: Check pkg-config install
Currently the reader of set_ftrace_filter and set_ftrace_notrace just adds
the pointer to the global tracer hash to its iterator. Unlike the writer
that allocates a copy of the hash, the reader keeps the pointer to the
filter hashes. This is problematic because this pointer is static across
function calls that release the locks that can update the global tracer
hashes. This can cause UAF and similar bugs.
Allocate and copy the hash for reading the filter files like it is done
for the writers. This not only fixes UAF bugs, but also makes the code a
bit simpler as it doesn't have to differentiate when to free the
iterator's hash between writers and readers.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20250822183606.12962cc3@batman.local.home
Fixes: c20489dad1 ("ftrace: Assign iter->hash to filter or notrace hashes on seq read")
Closes: https://lore.kernel.org/all/20250813023044.2121943-1-wutengda@huaweicloud.com/
Closes: https://lore.kernel.org/all/20250822192437.GA458494@ax162/
Reported-by: Tengda Wu <wutengda@huaweicloud.com>
Tested-by: Tengda Wu <wutengda@huaweicloud.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When calling ftrace_dump_one() concurrently with reading trace_pipe,
a WARN_ON_ONCE() in trace_printk_seq() can be triggered due to a race
condition.
The issue occurs because:
CPU0 (ftrace_dump) CPU1 (reader)
echo z > /proc/sysrq-trigger
!trace_empty(&iter)
trace_iterator_reset(&iter) <- len = size = 0
cat /sys/kernel/tracing/trace_pipe
trace_find_next_entry_inc(&iter)
__find_next_entry
ring_buffer_empty_cpu <- all empty
return NULL
trace_printk_seq(&iter.seq)
WARN_ON_ONCE(s->seq.len >= s->seq.size)
In the context between trace_empty() and trace_find_next_entry_inc()
during ftrace_dump, the ring buffer data was consumed by other readers.
This caused trace_find_next_entry_inc to return NULL, failing to populate
`iter.seq`. At this point, due to the prior trace_iterator_reset, both
`iter.seq.len` and `iter.seq.size` were set to 0. Since they are equal,
the WARN_ON_ONCE condition is triggered.
Move the trace_printk_seq() into the if block that checks to make sure the
return value of trace_find_next_entry_inc() is non-NULL in
ftrace_dump_one(), ensuring the 'iter.seq' is properly populated before
subsequent operations.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ingo Molnar <mingo@elte.hu>
Link: https://lore.kernel.org/20250822033343.3000289-1-wutengda@huaweicloud.com
Fixes: d769041f86 ("ring_buffer: implement new locking")
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The output of the function graph tracer has two ways to display its
entries. One way for leaf functions with no events recorded within them,
and the other is for functions with events recorded inside it. As function
graph has an entry and exit event, to simplify the output of leaf
functions it combines the two, where as non leaf functions are separate:
2) | invoke_rcu_core() {
2) | raise_softirq() {
2) 0.391 us | __raise_softirq_irqoff();
2) 1.191 us | }
2) 2.086 us | }
The __raise_softirq_irqoff() function above is really two events that were
merged into one. Otherwise it would have looked like:
2) | invoke_rcu_core() {
2) | raise_softirq() {
2) | __raise_softirq_irqoff() {
2) 0.391 us | }
2) 1.191 us | }
2) 2.086 us | }
In order to do this merge, the reading of the trace output file needs to
look at the next event before printing. But since the pointer to the event
is on the ring buffer, it needs to save the entry event before it looks at
the next event as the next event goes out of focus as soon as a new event
is read from the ring buffer. After it reads the next event, it will print
the entry event with either the '{' (non leaf) or ';' and timestamps (leaf).
The iterator used to read the trace file has storage for this event. The
problem happens when the function graph tracer has arguments attached to
the entry event as the entry now has a variable length "args" field. This
field only gets set when funcargs option is used. But the args are not
recorded in this temp data and garbage could be printed. The entry field
is copied via:
data->ent = *curr;
Where "curr" is the entry field. But this method only saves the non
variable length fields from the structure.
Add a helper structure to the iterator data that adds the max args size to
the data storage in the iterator. Then simply copy the entire entry into
this storage (with size protection).
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/20250820195522.51d4a268@gandalf.local.home
Reported-by: Sasha Levin <sashal@kernel.org>
Tested-by: Sasha Levin <sashal@kernel.org>
Closes: https://lore.kernel.org/all/aJaxRVKverIjF4a6@lappy/
Fixes: ff5c9c576e ("ftrace: Add support for function argument to graph tracer")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Fprobe event accepts wildcards for the target functions, but unless user
specifies its event name, it makes an event with the wildcards.
/sys/kernel/tracing # echo 'f mutex*' >> dynamic_events
/sys/kernel/tracing # cat dynamic_events
f:fprobes/mutex*__entry mutex*
/sys/kernel/tracing # ls events/fprobes/
enable filter mutex*__entry
To fix this, replace the wildcard ('*') with an underscore.
Link: https://lore.kernel.org/all/175535345114.282990.12294108192847938710.stgit@devnote2/
Fixes: 334e5519c3 ("tracing/probes: Add fprobe events for tracing function entry and exit.")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
This warning was triggered during testing on v6.16:
notifier callback ftrace_suspend_notifier_call already registered
WARNING: CPU: 2 PID: 86 at kernel/notifier.c:23 notifier_chain_register+0x44/0xb0
...
Call Trace:
<TASK>
blocking_notifier_chain_register+0x34/0x60
register_ftrace_graph+0x330/0x410
ftrace_profile_write+0x1e9/0x340
vfs_write+0xf8/0x420
? filp_flush+0x8a/0xa0
? filp_close+0x1f/0x30
? do_dup2+0xaf/0x160
ksys_write+0x65/0xe0
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x77/0x7f
When writing to the function_profile_enabled interface, the notifier was
not unregistered after start_graph_tracing failed, causing a warning the
next time function_profile_enabled was written.
Fixed by adding unregister_pm_notifier in the exception path.
Link: https://lore.kernel.org/20250818073332.3890629-1-yeweihua4@huawei.com
Fixes: 4a2b8dda3f ("tracing/function-graph-tracer: fix a regression while suspend to disk")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Ye Weihua <yeweihua4@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When the length of the string written to set_ftrace_filter exceeds
FTRACE_BUFF_MAX, the following KASAN alarm will be triggered:
BUG: KASAN: slab-out-of-bounds in strsep+0x18c/0x1b0
Read of size 1 at addr ffff0000d00bd5ba by task ash/165
CPU: 1 UID: 0 PID: 165 Comm: ash Not tainted 6.16.0-g6bcdbd62bd56-dirty
Hardware name: linux,dummy-virt (DT)
Call trace:
show_stack+0x34/0x50 (C)
dump_stack_lvl+0xa0/0x158
print_address_description.constprop.0+0x88/0x398
print_report+0xb0/0x280
kasan_report+0xa4/0xf0
__asan_report_load1_noabort+0x20/0x30
strsep+0x18c/0x1b0
ftrace_process_regex.isra.0+0x100/0x2d8
ftrace_regex_release+0x484/0x618
__fput+0x364/0xa58
____fput+0x28/0x40
task_work_run+0x154/0x278
do_notify_resume+0x1f0/0x220
el0_svc+0xec/0xf0
el0t_64_sync_handler+0xa0/0xe8
el0t_64_sync+0x1ac/0x1b0
The reason is that trace_get_user will fail when processing a string
longer than FTRACE_BUFF_MAX, but not set the end of parser->buffer to 0.
Then an OOB access will be triggered in ftrace_regex_release->
ftrace_process_regex->strsep->strpbrk. We can solve this problem by
limiting access to parser->buffer when trace_get_user failed.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250813040232.1344527-1-pulehui@huaweicloud.com
Fixes: 8c9af478c0 ("ftrace: Handle commands when closing set_ftrace_filter file")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Graph tracer framework ensures we won't migrate, kprobe_multi_link_prog_run
called all the way from graph tracer, which disables preemption in
function_graph_enter_regs, as Jiri and Yonghong suggested, there is no
need to use migrate_disable. As a result, some overhead may will be reduced.
And add cant_sleep check for __this_cpu_inc_return.
Fixes: 0dcac27254 ("bpf: Add multi kprobe link")
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250814121430.2347454-1-chen.dylane@linux.dev
- The 2 patch series "squashfs: Remove page->mapping references" from
Matthew Wilcox gets us closer to being able to remove page->mapping.
- The 5 patch series "relayfs: misc changes" from Jason Xing does some
maintenance and minor feature addition work in relayfs.
- The 5 patch series "kdump: crashkernel reservation from CMA" from Jiri
Bohac switches us from static preallocation of the kdump crashkernel's
working memory over to dynamic allocation. So the difficulty of
a-priori estimation of the second kernel's needs is removed and the
first kernel obtains extra memory.
- The 5 patch series "generalize panic_print's dump function to be used
by other kernel parts" from Feng Tang implements some consolidation and
rationalizatio of the various ways in which a faiing kernel splats
information at the operator.
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Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
"Significant patch series in this pull request:
- "squashfs: Remove page->mapping references" (Matthew Wilcox) gets
us closer to being able to remove page->mapping
- "relayfs: misc changes" (Jason Xing) does some maintenance and
minor feature addition work in relayfs
- "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
us from static preallocation of the kdump crashkernel's working
memory over to dynamic allocation. So the difficulty of a-priori
estimation of the second kernel's needs is removed and the first
kernel obtains extra memory
- "generalize panic_print's dump function to be used by other
kernel parts" (Feng Tang) implements some consolidation and
rationalization of the various ways in which a failing kernel
splats information at the operator
* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
tools/getdelays: add backward compatibility for taskstats version
kho: add test for kexec handover
delaytop: enhance error logging and add PSI feature description
samples: Kconfig: fix spelling mistake "instancess" -> "instances"
fat: fix too many log in fat_chain_add()
scripts/spelling.txt: add notifer||notifier to spelling.txt
xen/xenbus: fix typo "notifer"
net: mvneta: fix typo "notifer"
drm/xe: fix typo "notifer"
cxl: mce: fix typo "notifer"
KVM: x86: fix typo "notifer"
MAINTAINERS: add maintainers for delaytop
ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
ucount: fix atomic_long_inc_below() argument type
kexec: enable CMA based contiguous allocation
stackdepot: make max number of pools boot-time configurable
lib/xxhash: remove unused functions
init/Kconfig: restore CONFIG_BROKEN help text
lib/raid6: update recov_rvv.c zero page usage
docs: update docs after introducing delaytop
...
- Remove unneeded goto out statements
Over time, the logic was restructured but left a "goto out" where the
out label simply did a "return ret;". Instead of jumping to this out
label, simply return immediately and remove the out label.
- Add guard(ring_buffer_nest)
Some calls to the tracing ring buffer can happen when the ring buffer is
already being written to at the same context (for example, a
trace_printk() in between a ring_buffer_lock_reserve() and a
ring_buffer_unlock_commit()).
In order to not trigger the recursion detection, these functions use
ring_buffer_nest_start() and ring_buffer_nest_end(). Create a guard() for
these functions so that their use cases can be simplified and not need to
use goto for the release.
- Clean up the tracing code with guard() and __free() logic
There were several locations that were prime candidates for using guard()
and __free() helpers. Switch them over to use them.
- Fix output of function argument traces for unsigned int values
The function tracer with "func-args" option set will record up to 6 argument
registers and then use BTF to format them for human consumption when the
trace file is read. There's several arguments that are "unsigned long" and
even "unsigned int" that are either and address or a mask. It is easier to
understand if they were printed using hexadecimal instead of decimal.
The old method just printed all non-pointer values as signed integers,
which made it even worse for unsigned integers.
For instance, instead of:
__local_bh_disable_ip(ip=-2127311112, cnt=256) <-handle_softirqs
Show:
__local_bh_disable_ip(ip=0xffffffff8133cef8, cnt=0x100) <-handle_softirqs
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Merge tag 'trace-v6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull more tracing updates from Steven Rostedt:
- Remove unneeded goto out statements
Over time, the logic was restructured but left a "goto out" where the
out label simply did a "return ret;". Instead of jumping to this out
label, simply return immediately and remove the out label.
- Add guard(ring_buffer_nest)
Some calls to the tracing ring buffer can happen when the ring buffer
is already being written to at the same context (for example, a
trace_printk() in between a ring_buffer_lock_reserve() and a
ring_buffer_unlock_commit()).
In order to not trigger the recursion detection, these functions use
ring_buffer_nest_start() and ring_buffer_nest_end(). Create a guard()
for these functions so that their use cases can be simplified and not
need to use goto for the release.
- Clean up the tracing code with guard() and __free() logic
There were several locations that were prime candidates for using
guard() and __free() helpers. Switch them over to use them.
- Fix output of function argument traces for unsigned int values
The function tracer with "func-args" option set will record up to 6
argument registers and then use BTF to format them for human
consumption when the trace file is read. There are several arguments
that are "unsigned long" and even "unsigned int" that are either and
address or a mask. It is easier to understand if they were printed
using hexadecimal instead of decimal. The old method just printed all
non-pointer values as signed integers, which made it even worse for
unsigned integers.
For instance, instead of:
__local_bh_disable_ip(ip=-2127311112, cnt=256) <-handle_softirqs
show:
__local_bh_disable_ip(ip=0xffffffff8133cef8, cnt=0x100) <-handle_softirqs"
* tag 'trace-v6.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Have unsigned int function args displayed as hexadecimal
ring-buffer: Convert ring_buffer_write() to use guard(preempt_notrace)
tracing: Use __free(kfree) in trace.c to remove gotos
tracing: Add guard() around locks and mutexes in trace.c
tracing: Add guard(ring_buffer_nest)
tracing: Remove unneeded goto out logic
to use the module data structures in combination with the already no-op stub
module functions, even when support for modules is disabled in the kernel
configuration. This change follows the kernel's coding style for conditional
compilation and allows kunit code to drop all CONFIG_MODULES ifdefs, which is
also part of the changes. This should allow others part of the kernel to do the
same cleanup.
Note that this had a conflict with sysctl changes [1] but should be fixed now as I
rebased on top.
The remaining changes include a fix for module name length handling which could
potentially lead to the removal of an incorrect module, and various cleanups.
The module name fix and related cleanup has been in linux-next since Thursday
(July 31) while the rest of the changes for a bit more than 3 weeks.
Note that this currently has conflicts in next with kbuild's tree [2].
Link: https://lore.kernel.org/all/20250714175916.774e6d79@canb.auug.org.au/ [1]
Link: https://lore.kernel.org/all/20250801132941.6815d93d@canb.auug.org.au/ [2]
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Merge tag 'modules-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux
Pull module updates from Daniel Gomez:
"This is a small set of changes for modules, primarily to extend module
users to use the module data structures in combination with the
already no-op stub module functions, even when support for modules is
disabled in the kernel configuration. This change follows the kernel's
coding style for conditional compilation and allows kunit code to drop
all CONFIG_MODULES ifdefs, which is also part of the changes. This
should allow others part of the kernel to do the same cleanup.
The remaining changes include a fix for module name length handling
which could potentially lead to the removal of an incorrect module,
and various cleanups"
* tag 'modules-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
module: Rename MAX_PARAM_PREFIX_LEN to __MODULE_NAME_LEN
tracing: Replace MAX_PARAM_PREFIX_LEN with MODULE_NAME_LEN
module: Restore the moduleparam prefix length check
module: Remove unnecessary +1 from last_unloaded_module::name size
module: Prevent silent truncation of module name in delete_module(2)
kunit: test: Drop CONFIG_MODULE ifdeffery
module: make structure definitions always visible
module: move 'struct module_use' to internal.h
Most function arguments that are passed in as unsigned int or unsigned
long are better displayed as hexadecimal than normal integer. For example,
the functions:
static void __create_object(unsigned long ptr, size_t size,
int min_count, gfp_t gfp, unsigned int objflags);
static bool stack_access_ok(struct unwind_state *state, unsigned long _addr,
size_t len);
void __local_bh_disable_ip(unsigned long ip, unsigned int cnt);
Show up in the trace as:
__create_object(ptr=-131387050520576, size=4096, min_count=1, gfp=3264, objflags=0) <-kmem_cache_alloc_noprof
stack_access_ok(state=0xffffc9000233fc98, _addr=-60473102566256, len=8) <-unwind_next_frame
__local_bh_disable_ip(ip=-2127311112, cnt=256) <-handle_softirqs
Instead, by displaying unsigned as hexadecimal, they look more like this:
__create_object(ptr=0xffff8881028d2080, size=0x280, min_count=1, gfp=0x82820, objflags=0x0) <-kmem_cache_alloc_node_noprof
stack_access_ok(state=0xffffc90000003938, _addr=0xffffc90000003930, len=0x8) <-unwind_next_frame
__local_bh_disable_ip(ip=0xffffffff8133cef8, cnt=0x100) <-handle_softirqs
Which is much easier to understand as most unsigned longs are usually just
pointers. Even the "unsigned int cnt" in __local_bh_disable_ip() looks
better as hexadecimal as a lot of flags are passed as unsigned.
Changes since v2: https://lore.kernel.org/20250801111453.01502861@gandalf.local.home
- Use btf_int_encoding() instead of open coding it (Martin KaFai Lau)
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Link: https://lore.kernel.org/20250801165601.7770d65c@gandalf.local.home
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function ring_buffer_write() has a goto out to only do a
preempt_enable_notrace(). This can be replaced by a guard.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250801203858.205479143@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
There's a couple of locations that have goto out in trace.c for the only
purpose of freeing a variable that was allocated. These can be replaced
with __free(kfree).
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250801203858.040892777@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
There's several locations in trace.c that can be simplified by using
guards around raw_spin_lock_irqsave, mutexes and preempt disabling.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250801203857.879085376@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Some calls to the tracing ring buffer can happen when the ring buffer is
already being written to by the same context (for example, a
trace_printk() in between a ring_buffer_lock_reserve() and a
ring_buffer_unlock_commit()).
In order to not trigger the recursion detection, these functions use
ring_buffer_nest_start() and ring_buffer_nest_end(). Create a guard() for
these functions so that their use cases can be simplified and not need to
use goto for the release.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250801203857.710501021@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Several places in the trace.c file there's a goto out where the out is
simply a return. There's no reason to jump to the out label if it's not
doing any more logic but simply returning from the function.
Replace the goto outs with a return and remove the out labels.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250801203857.538726745@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Deprecate auto-mounting tracefs to /sys/kernel/debug/tracing
When tracefs was first introduced back in 2014, the directory
/sys/kernel/tracing was added and is the designated location to mount
tracefs. To keep backward compatibility, tracefs was auto-mounted in
/sys/kernel/debug/tracing as well.
All distros now mount tracefs on /sys/kernel/tracing. Having it seen in two
different locations has lead to various issues and inconsistencies.
The VFS folks have to also maintain debugfs_create_automount() for this
single user.
It's been over 10 years. Tooling and scripts should start replacing the
debugfs location with the tracefs one. The reason tracefs was created in the
first place was to allow access to the tracing facilities without the need
to configure debugfs into the kernel. Using tracefs should now be more
robust.
A new config is created: CONFIG_TRACEFS_AUTOMOUNT_DEPRECATED
which is default y, so that the kernel is still built with the automount.
This config allows those that want to remove the automount from debugfs to
do so.
When tracefs is accessed from /sys/kernel/debug/tracing, the following
printk is triggerd:
pr_warn("NOTICE: Automounting of tracing to debugfs is deprecated and will be removed in 2030\n");
This gives users another 5 years to fix their scripts.
- Use queue_rcu_work() instead of call_rcu() for freeing event filters
The number of filters to be free can be many depending on the number of
events within an event system. Freeing them from softirq context can
potentially cause undesired latency. Use the RCU workqueue to free them
instead.
- Remove pointless memory barriers in latency code
Memory barriers were added to some of the latency code a long time ago with
the idea of "making them visible", but that's not what memory barriers are
for. They are to synchronize access between different variables. There was
no synchronization here making them pointless.
- Remove "__attribute__()" from the type field of event format
When LLVM is used to compile the kernel with CONFIG_DEBUG_INFO_BTF=y and
PAHOLE_HAS_BTF_TAG=y, some of the format fields get expanded with the
following:
field:const char * filename; offset:24; size:8; signed:0;
Turns into:
field:const char __attribute__((btf_type_tag("user"))) * filename; offset:24; size:8; signed:0;
This confuses parsers. Add code to strip these tags from the strings.
- Add eprobe config option CONFIG_EPROBE_EVENTS
Eprobes were added back in 5.15 but were only enabled when another probe was
enabled (kprobe, fprobe, uprobe, etc). The eprobes had no config option
of their own. Add one as they should be a separate entity.
It's default y to keep with the old kernels but still has dependencies on
TRACING and HAVE_REGS_AND_STACK_ACCESS_API.
- Add eprobe documentation
When eprobes were added back in 5.15 no documentation was added to describe
them. This needs to be rectified.
- Replace open coded cpumask_next_wrap() in move_to_next_cpu()
- Have preemptirq_delay_run() use off-stack CPU mask
- Remove obsolete comment about pelt_cfs event
DECLARE_TRACE() appends "_tp" to trace events now, but the comment above
pelt_cfs still mentioned appending it manually.
- Remove EVENT_FILE_FL_SOFT_MODE flag
The SOFT_MODE flag was required when the soft enabling and disabling of
trace events was first introduced. But there was a bug with this approach
as it only worked for a single instance. When multiple users required soft
disabling and disabling the code was changed to have a ref count. The
SOFT_MODE flag is now set iff the ref count is non zero. This is redundant
and just reading the ref count is good enough.
- Fix typo in comment
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Merge tag 'trace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Deprecate auto-mounting tracefs to /sys/kernel/debug/tracing
When tracefs was first introduced back in 2014, the directory
/sys/kernel/tracing was added and is the designated location to mount
tracefs. To keep backward compatibility, tracefs was auto-mounted in
/sys/kernel/debug/tracing as well.
All distros now mount tracefs on /sys/kernel/tracing. Having it seen
in two different locations has lead to various issues and
inconsistencies.
The VFS folks have to also maintain debugfs_create_automount() for
this single user.
It's been over 10 years. Tooling and scripts should start replacing
the debugfs location with the tracefs one. The reason tracefs was
created in the first place was to allow access to the tracing
facilities without the need to configure debugfs into the kernel.
Using tracefs should now be more robust.
A new config is created: CONFIG_TRACEFS_AUTOMOUNT_DEPRECATED which is
default y, so that the kernel is still built with the automount. This
config allows those that want to remove the automount from debugfs to
do so.
When tracefs is accessed from /sys/kernel/debug/tracing, the
following printk is triggerd:
pr_warn("NOTICE: Automounting of tracing to debugfs is deprecated and will be removed in 2030\n");
This gives users another 5 years to fix their scripts.
- Use queue_rcu_work() instead of call_rcu() for freeing event filters
The number of filters to be free can be many depending on the number
of events within an event system. Freeing them from softirq context
can potentially cause undesired latency. Use the RCU workqueue to
free them instead.
- Remove pointless memory barriers in latency code
Memory barriers were added to some of the latency code a long time
ago with the idea of "making them visible", but that's not what
memory barriers are for. They are to synchronize access between
different variables. There was no synchronization here making them
pointless.
- Remove "__attribute__()" from the type field of event format
When LLVM is used to compile the kernel with CONFIG_DEBUG_INFO_BTF=y
and PAHOLE_HAS_BTF_TAG=y, some of the format fields get expanded with
the following:
field:const char * filename; offset:24; size:8; signed:0;
Turns into:
field:const char __attribute__((btf_type_tag("user"))) * filename; offset:24; size:8; signed:0;
This confuses parsers. Add code to strip these tags from the strings.
- Add eprobe config option CONFIG_EPROBE_EVENTS
Eprobes were added back in 5.15 but were only enabled when another
probe was enabled (kprobe, fprobe, uprobe, etc). The eprobes had no
config option of their own. Add one as they should be a separate
entity.
It's default y to keep with the old kernels but still has
dependencies on TRACING and HAVE_REGS_AND_STACK_ACCESS_API.
- Add eprobe documentation
When eprobes were added back in 5.15 no documentation was added to
describe them. This needs to be rectified.
- Replace open coded cpumask_next_wrap() in move_to_next_cpu()
- Have preemptirq_delay_run() use off-stack CPU mask
- Remove obsolete comment about pelt_cfs event
DECLARE_TRACE() appends "_tp" to trace events now, but the comment
above pelt_cfs still mentioned appending it manually.
- Remove EVENT_FILE_FL_SOFT_MODE flag
The SOFT_MODE flag was required when the soft enabling and disabling
of trace events was first introduced. But there was a bug with this
approach as it only worked for a single instance. When multiple users
required soft disabling and disabling the code was changed to have a
ref count. The SOFT_MODE flag is now set iff the ref count is non
zero. This is redundant and just reading the ref count is good
enough.
- Fix typo in comment
* tag 'trace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
Documentation: tracing: Add documentation about eprobes
tracing: Have eprobes have their own config option
tracing: Remove "__attribute__()" from the type field of event format
tracing: Deprecate auto-mounting tracefs in debugfs
tracing: Fix comment in trace_module_remove_events()
tracing: Remove EVENT_FILE_FL_SOFT_MODE flag
tracing: Remove pointless memory barriers
tracing/sched: Remove obsolete comment on suffixes
kernel: trace: preemptirq_delay_test: use offstack cpu mask
tracing: Use queue_rcu_work() to free filters
tracing: Replace opencoded cpumask_next_wrap() in move_to_next_cpu()
Use the MODULE_NAME_LEN definition in module_exists() to obtain the maximum
size of a module name, instead of using MAX_PARAM_PREFIX_LEN. The values
are the same but MODULE_NAME_LEN is more appropriate in this context.
MAX_PARAM_PREFIX_LEN was added in commit 730b69d225 ("module: check
kernel param length at compile time, not runtime") only to break a circular
dependency between module.h and moduleparam.h, and should mostly be limited
to use in moduleparam.h.
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Daniel Gomez <da.gomez@samsung.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20250630143535.267745-5-petr.pavlu@suse.com
Signed-off-by: Daniel Gomez <da.gomez@samsung.com>
Tracepoints take up memory (around 5K per tracepoint) even when they are
unused. Changes are being made to detect when a tracepoint is defined but
unused and a warning is shown at build. But those changes are not yet
ready for inclusion.
- Fix some of the unused tracepoints that it detected
Some tracepoints were removed and others were hidden by config settings
to match the config settings of where they are instantiated. Some
tracepoints were moved into architecture specific code as only one
architecture used them.
- Call the ftrace_test_filter tracepoint in an unreachable if statement
The ftrace_test_filter tracepoint which is defined when ftrace selftests
are configured and is used to test the filter logic, but the tracepoint is
not actually called. It is put into an if statement to not have it get
compiled out, but also not warn for not being used.
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Merge tag 'trace-unused-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracepoint cleanup from Steven Rostedt:
"Remove or hide unused tracepoints
Tracepoints take up memory (around 5K per tracepoint) even when they
are unused. Changes are being made to detect when a tracepoint is
defined but unused and a warning is shown at build. But those changes
are not yet ready for inclusion.
- Fix some of the unused tracepoints that it detected
Some tracepoints were removed and others were hidden by config
settings to match the config settings of where they are
instantiated. Some tracepoints were moved into architecture
specific code as only one architecture used them.
- Call the ftrace_test_filter tracepoint in an unreachable if
statement
The ftrace_test_filter tracepoint which is defined when ftrace
selftests are configured and is used to test the filter logic, but
the tracepoint is not actually called. It is put into an if
statement to not have it get compiled out, but also not warn for
not being used"
* tag 'trace-unused-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: sched: Hide numa events under CONFIG_NUMA_BALANCING
powerpc/thp: tracing: Hide hugepage events under CONFIG_PPC_BOOK3S_64
tracing: Call trace_ftrace_test_filter() for the event
tracing: arm: arm64: Hide trace events ipi_raise, ipi_entry and ipi_exit
binder: Remove unused binder lock events
PM: tracing: Hide power_domain_target event under ARCH_OMAP2PLUS
PM: tracing: Hide device_pm_callback events under PM_SLEEP
PM: tracing: Hide psci_domain_idle events under ARM_PSCI_CPUIDLE
PM: cpufreq: powernv/tracing: Move powernv_throttle trace event
alarmtimer: Hide alarmtimer_suspend event when RTC_CLASS is not configured
tracing, AER: Hide PCIe AER event when PCIEAER is not configured
- Added Linear temporal logic monitors for RT application
Real-time applications may have design flaws causing them to have
unexpected latency. For example, the applications may raise page faults, or
may be blocked trying to take a mutex without priority inheritance.
However, while attempting to implement DA monitors for these real-time
rules, deterministic automaton is found to be inappropriate as the
specification language. The automaton is complicated, hard to understand,
and error-prone.
For these cases, linear temporal logic is found to be more suitable. The
LTL is more concise and intuitive.
- Make printk_deferred() public
The new monitors needed access to printk_deferred(). Make them visible for
the entire kernel.
- Add a vpanic() to allow for va_list to be passed to panic.
- Add rtapp container monitor.
A collection of monitors that check for common problems with real-time
applications that cause unexpected latency.
- Add page fault tracepoints to risc-v
These tracepoints are necessary to for the RV monitor to run on risc-v.
- Fix the behaviour of the rv tool with -s and idle tasks.
- Allow the rv tool to gracefully terminate with SIGTERM
- Adjusts dot2c not to create lines over 100 columns
- Properly order nested monitors in the RV Kconfig file
- Return the registration error in all DA monitor instead of 0
- Update and add new sched collection monitors
Replace tss and sncid monitors with more complete sts:
Not only prove that switches occur in scheduling context and scheduling
needs interrupt disabled but also that each call to the scheduler
disables interrupts to (optionally) switch.
New monitor: nrp
Preemption requires need resched which is cleared by any switch
(includes a non optimal workaround for /nested/ preemptions)
New monitor: sssw
suspension requires setting the task to sleepable and, after the
switch occurs, the task requires a wakeup to come back to runnable
New monitor: opid
waking and need-resched operations occur with interrupts and
preemption disabled or in IRQ without explicitly disabling preemption
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Merge tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull runtime verification updates from Steven Rostedt:
- Added Linear temporal logic monitors for RT application
Real-time applications may have design flaws causing them to have
unexpected latency. For example, the applications may raise page
faults, or may be blocked trying to take a mutex without priority
inheritance.
However, while attempting to implement DA monitors for these
real-time rules, deterministic automaton is found to be inappropriate
as the specification language. The automaton is complicated, hard to
understand, and error-prone.
For these cases, linear temporal logic is found to be more suitable.
The LTL is more concise and intuitive.
- Make printk_deferred() public
The new monitors needed access to printk_deferred(). Make them
visible for the entire kernel.
- Add a vpanic() to allow for va_list to be passed to panic.
- Add rtapp container monitor.
A collection of monitors that check for common problems with
real-time applications that cause unexpected latency.
- Add page fault tracepoints to risc-v
These tracepoints are necessary to for the RV monitor to run on
risc-v.
- Fix the behaviour of the rv tool with -s and idle tasks.
- Allow the rv tool to gracefully terminate with SIGTERM
- Adjusts dot2c not to create lines over 100 columns
- Properly order nested monitors in the RV Kconfig file
- Return the registration error in all DA monitor instead of 0
- Update and add new sched collection monitors
Replace tss and sncid monitors with more complete sts:
Not only prove that switches occur in scheduling context and scheduling
needs interrupt disabled but also that each call to the scheduler
disables interrupts to (optionally) switch.
New monitor: nrp
Preemption requires need resched which is cleared by any switch
(includes a non optimal workaround for /nested/ preemptions)
New monitor: sssw
suspension requires setting the task to sleepable and, after the
switch occurs, the task requires a wakeup to come back to runnable
New monitor: opid
waking and need-resched operations occur with interrupts and
preemption disabled or in IRQ without explicitly disabling
preemption"
* tag 'trace-rv-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (48 commits)
rv: Add opid per-cpu monitor
rv: Add nrp and sssw per-task monitors
rv: Replace tss and sncid monitors with more complete sts
sched: Adapt sched tracepoints for RV task model
rv: Retry when da monitor detects race conditions
rv: Adjust monitor dependencies
rv: Use strings in da monitors tracepoints
rv: Remove trailing whitespace from tracepoint string
rv: Add da_handle_start_run_event_ to per-task monitors
rv: Fix wrong type cast in reactors_show() and monitor_reactor_show()
rv: Fix wrong type cast in monitors_show()
rv: Remove struct rv_monitor::reacting
rv: Remove rv_reactor's reference counter
rv: Merge struct rv_reactor_def into struct rv_reactor
rv: Merge struct rv_monitor_def into struct rv_monitor
rv: Remove unused field in struct rv_monitor_def
rv: Return init error when registering monitors
verification/rvgen: Organise Kconfig entries for nested monitors
tools/dot2c: Fix generated files going over 100 column limit
tools/rv: Stop gracefully also on SIGTERM
...
- Rewind persistent ring buffer on boot
When the persistent ring buffer is being used for live kernel tracing and
the system crashes, the tool that is reading the trace may not have recorded
the data when the system crashed. Although the persistent ring buffer still
has that data, when reading it after a reboot, it will start where it left
off. That is, what was read will not be accessible.
Instead, on reboot, have the persistent ring buffer restart where the data
starts and this will allow the tooling to recover what was lost when the
crash occurred.
- Remove the ring_buffer_read_prepare_sync() logic
Reading the trace file required stopping writing to the ring buffer as the
trace file is only an iterator and does not consume what it read. It was
originally not safe to read the ring buffer in this mode and required
disabling writing. The ring_buffer_read_prepare_sync() logic was used to
stop each per_cpu ring buffer, call synchronize_rcu() and then start the
iterator. This was used instead of calling synchronize_rcu() for each
per_cpu buffer.
Today, the iterator has been updated where it is safe to read the trace file
while writing to the ring buffer is still occurring. There is no more need
to do this synchronization and it is causing large delays on machines with
many CPUs. Remove this unneeded synchronization.
- Make static string array a constant in show_irq_str()
Making the string array into a constant has shown to decrease code text/data
size.
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Merge tag 'trace-ringbuffer-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer updates from Steven Rostedt:
- Rewind persistent ring buffer on boot
When the persistent ring buffer is being used for live kernel tracing
and the system crashes, the tool that is reading the trace may not
have recorded the data when the system crashed.
Although the persistent ring buffer still has that data, when reading
it after a reboot, it will start where it left off. That is, what was
read will not be accessible.
Instead, on reboot, have the persistent ring buffer restart where the
data starts and this will allow the tooling to recover what was lost
when the crash occurred.
- Remove the ring_buffer_read_prepare_sync() logic
Reading the trace file required stopping writing to the ring buffer
as the trace file is only an iterator and does not consume what it
read. It was originally not safe to read the ring buffer in this mode
and required disabling writing. The ring_buffer_read_prepare_sync()
logic was used to stop each per_cpu ring buffer, call
synchronize_rcu() and then start the iterator. This was used instead
of calling synchronize_rcu() for each per_cpu buffer.
Today, the iterator has been updated where it is safe to read the
trace file while writing to the ring buffer is still occurring. There
is no more need to do this synchronization and it is causing large
delays on machines with many CPUs. Remove this unneeded
synchronization.
- Make static string array a constant in show_irq_str()
Making the string array into a constant has shown to decrease code
text/data size.
* tag 'trace-ringbuffer-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Make the const read-only 'type' static
ring-buffer: Remove ring_buffer_read_prepare_sync()
tracing: ring_buffer: Rewind persistent ring buffer on reboot
- Keep track of when fgraph_ops are registered or not
Keep accounting of when fgraph_ops are registered as if a fgraph_ops is
registered twice it can mess up the accounting and it will not work as
expected later. Trigger a warning if something registers it twice as to
catch bugs before they are found by things just not working as expected.
- Make DYNAMIC_FTRACE always enabled for architectures that support it
As static ftrace (where all functions are always traced) is very expensive
and only exists to help architectures support ftrace, do not make it an
option. As soon as an architecture supports DYNAMIC_FTRACE make it use it.
This simplifies the code.
- Remove redundant config HAVE_FTRACE_MCOUNT_RECORD
The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the
DYNAMIC_FTRACE work, but now every architecture that implements
DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it redundant
with the HAVE_DYNAMIC_FTRACE.
- Make pid_ptr string size match the comment
In print_graph_proc() the pid_ptr string is of size 11, but the comment says
/* sign + log10(MAX_INT) + '\0' */ which is actually 12.
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Merge tag 'ftrace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace updates from Steven Rostedt:
- Keep track of when fgraph_ops are registered or not
Keep accounting of when fgraph_ops are registered as if a fgraph_ops
is registered twice it can mess up the accounting and it will not
work as expected later. Trigger a warning if something registers it
twice as to catch bugs before they are found by things just not
working as expected.
- Make DYNAMIC_FTRACE always enabled for architectures that support it
As static ftrace (where all functions are always traced) is very
expensive and only exists to help architectures support ftrace, do
not make it an option. As soon as an architecture supports
DYNAMIC_FTRACE make it use it. This simplifies the code.
- Remove redundant config HAVE_FTRACE_MCOUNT_RECORD
The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the
DYNAMIC_FTRACE work, but now every architecture that implements
DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it
redundant with the HAVE_DYNAMIC_FTRACE.
- Make pid_ptr string size match the comment
In print_graph_proc() the pid_ptr string is of size 11, but the
comment says /* sign + log10(MAX_INT) + '\0' */ which is actually 12.
* tag 'ftrace-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Remove redundant config HAVE_FTRACE_MCOUNT_RECORD
ftrace: Make DYNAMIC_FTRACE always enabled for architectures that support it
fgraph: Keep track of when fgraph_ops are registered or not
fgraph: Make pid_str size match the comment
- Stack usage reduction for probe events:
- Allocate string buffers from the heap for uprobe, eprobe, kprobe,
and fprobe events to avoid stack overflow.
- Allocate traceprobe_parse_context from the heap to prevent
potential stack overflow.
- Fix a typo in the above commit.
- New features for eprobe and tprobe events:
- Add support for arrays in eprobes.
- Support multiple tprobes on the same tracepoint.
- Improve efficiency:
- Register fprobe-events only when it is enabled to reduce overhead.
- Register tracepoints for tprobe events only when enabled to
resolve a lock dependency.
- Code Cleanup:
- Add kerneldoc for traceprobe_parse_event_name() and __get_insn_slot().
- Sort #include alphabetically in the probes code.
- Remove the unused 'mod' field from the tprobe-event.
- Clean up the entry-arg storing code in probe-events.
- Selftest update
- Enable fprobe events before checking enable_functions in selftests.
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Merge tag 'probes-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes updates from Masami Hiramatsu:
"Stack usage reduction for probe events:
- Allocate string buffers from the heap for uprobe, eprobe, kprobe,
and fprobe events to avoid stack overflow
- Allocate traceprobe_parse_context from the heap to prevent
potential stack overflow
- Fix a typo in the above commit
New features for eprobe and tprobe events:
- Add support for arrays in eprobes
- Support multiple tprobes on the same tracepoint
Improve efficiency:
- Register fprobe-events only when it is enabled to reduce overhead
- Register tracepoints for tprobe events only when enabled to resolve
a lock dependency
Code Cleanup:
- Add kerneldoc for traceprobe_parse_event_name() and
__get_insn_slot()
- Sort #include alphabetically in the probes code
- Remove the unused 'mod' field from the tprobe-event
- Clean up the entry-arg storing code in probe-events
Selftest update
- Enable fprobe events before checking enable_functions in selftests"
* tag 'probes-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: trace_fprobe: Fix typo of the semicolon
tracing: Have eprobes handle arrays
tracing: probes: Add a kerneldoc for traceprobe_parse_event_name()
tracing: uprobe-event: Allocate string buffers from heap
tracing: eprobe-event: Allocate string buffers from heap
tracing: kprobe-event: Allocate string buffers from heap
tracing: fprobe-event: Allocate string buffers from heap
tracing: probe: Allocate traceprobe_parse_context from heap
tracing: probes: Sort #include alphabetically
kprobes: Add missing kerneldoc for __get_insn_slot
tracing: tprobe-events: Register tracepoint when enable tprobe event
selftests: tracing: Enable fprobe events before checking enable_functions
tracing: fprobe-events: Register fprobe-events only when it is enabled
tracing: tprobe-events: Support multiple tprobes on the same tracepoint
tracing: tprobe-events: Remove mod field from tprobe-event
tracing: probe-events: Cleanup entry-arg storing code
- Fix a potential infinite recursion in fprobe by using preempt_*_notrace().
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Merge tag 'probes-fixes-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fix from Masami Hiramatsu:
- Fix a potential infinite recursion in fprobe by using preempt_*_notrace()
* tag 'probes-fixes-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: fprobe: Fix infinite recursion using preempt_*_notrace()
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Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Remove usermode driver (UMD) framework (Thomas Weißschuh)
- Introduce Strongly Connected Component (SCC) in the verifier to
detect loops and refine register liveness (Eduard Zingerman)
- Allow 'void *' cast using bpf_rdonly_cast() and corresponding
'__arg_untrusted' for global function parameters (Eduard Zingerman)
- Improve precision for BPF_ADD and BPF_SUB operations in the verifier
(Harishankar Vishwanathan)
- Teach the verifier that constant pointer to a map cannot be NULL
(Ihor Solodrai)
- Introduce BPF streams for error reporting of various conditions
detected by BPF runtime (Kumar Kartikeya Dwivedi)
- Teach the verifier to insert runtime speculation barrier (lfence on
x86) to mitigate speculative execution instead of rejecting the
programs (Luis Gerhorst)
- Various improvements for 'veristat' (Mykyta Yatsenko)
- For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to
improve bug detection by syzbot (Paul Chaignon)
- Support BPF private stack on arm64 (Puranjay Mohan)
- Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's
node (Song Liu)
- Introduce kfuncs for read-only string opreations (Viktor Malik)
- Implement show_fdinfo() for bpf_links (Tao Chen)
- Reduce verifier's stack consumption (Yonghong Song)
- Implement mprog API for cgroup-bpf programs (Yonghong Song)
* tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits)
selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite
selftests/bpf: Add selftest for attaching tracing programs to functions in deny list
bpf: Add log for attaching tracing programs to functions in deny list
bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions
bpf: Fix various typos in verifier.c comments
bpf: Add third round of bounds deduction
selftests/bpf: Test invariants on JSLT crossing sign
selftests/bpf: Test cross-sign 64bits range refinement
selftests/bpf: Update reg_bound range refinement logic
bpf: Improve bounds when s64 crosses sign boundary
bpf: Simplify bounds refinement from s32
selftests/bpf: Enable private stack tests for arm64
bpf, arm64: JIT support for private stack
bpf: Move bpf_jit_get_prog_name() to core.c
bpf, arm64: Fix fp initialization for exception boundary
umd: Remove usermode driver framework
bpf/preload: Don't select USERMODE_DRIVER
selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure
selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure
selftests/bpf: Increase xdp data size for arm64 64K page size
...
Eprobes were added in 5.15 and were selected whenever any of the other
probe events were selected. If kprobe events were enabled (which it is by
default if kprobes are enabled) it would enable eprobe events as well. The
same for uprobes and fprobes.
Have eprobes have its own config and it gets enabled by default if tracing
is enabled.
Link: https://lore.kernel.org/all/20250729102636.b7cce553e7cc263722b12365@kernel.org/
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/20250730140945.360286733@kernel.org
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Don't populate the read-only 'type' on the stack at run time,
instead make it static.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250714160858.1234719-1-colin.i.king@gmail.com
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
With CONFIG_DEBUG_INFO_BTF=y and PAHOLE_HAS_BTF_TAG=y, `__user` is
converted to `__attribute__((btf_type_tag("user")))`. In this case,
some syscall events have it for __user data, like below;
/sys/kernel/tracing # cat events/syscalls/sys_enter_openat/format
name: sys_enter_openat
ID: 720
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:int __syscall_nr; offset:8; size:4; signed:1;
field:int dfd; offset:16; size:8; signed:0;
field:const char __attribute__((btf_type_tag("user"))) * filename; offset:24; size:8; signed:0;
field:int flags; offset:32; size:8; signed:0;
field:umode_t mode; offset:40; size:8; signed:0;
Then the trace event filter fails to set the string acceptable flag
(FILTER_PTR_STRING) to the field and rejects setting string filter;
# echo 'filename.ustring ~ "*ftracetest-dir.wbx24v*"' \
>> events/syscalls/sys_enter_openat/filter
sh: write error: Invalid argument
# cat error_log
[ 723.743637] event filter parse error: error: Expecting numeric field
Command: filename.ustring ~ "*ftracetest-dir.wbx24v*"
Since this __attribute__ makes format parsing complicated and not
needed, remove the __attribute__(.*) from the type string.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/175376583493.1688759.12333973498014733551.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Since preempt_count_add/del() are tracable functions, it is not allowed
to use preempt_disable/enable() in ftrace handlers. Without this fix,
probing on `preempt_count_add%return` will cause an infinite recursion
of fprobes.
To fix this problem, use preempt_disable/enable_notrace() in
fprobe_return().
Link: https://lore.kernel.org/all/175374642359.1471729.1054175011228386560.stgit@mhiramat.tok.corp.google.com/
Fixes: 4346ba1604 ("fprobe: Rewrite fprobe on function-graph tracer")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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Merge tag 'for-6.17/block-20250728' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- MD pull request via Yu:
- call del_gendisk synchronously (Xiao)
- cleanup unused variable (John)
- cleanup workqueue flags (Ryo)
- fix faulty rdev can't be removed during resync (Qixing)
- NVMe pull request via Christoph:
- try PCIe function level reset on init failure (Keith Busch)
- log TLS handshake failures at error level (Maurizio Lombardi)
- pci-epf: do not complete commands twice if nvmet_req_init()
fails (Rick Wertenbroek)
- misc cleanups (Alok Tiwari)
- Removal of the pktcdvd driver
This has been more than a decade coming at this point, and some
recently revealed breakages that had it causing issues even for cases
where it isn't required made me re-pull the trigger on this one. It's
known broken and nobody has stepped up to maintain the code
- Series for ublk supporting batch commands, enabling the use of
multishot where appropriate
- Speed up ublk exit handling
- Fix for the two-stage elevator fixing which could leak data
- Convert NVMe to use the new IOVA based API
- Increase default max transfer size to something more reasonable
- Series fixing write operations on zoned DM devices
- Add tracepoints for zoned block device operations
- Prep series working towards improving blk-mq queue management in the
presence of isolated CPUs
- Don't allow updating of the block size of a loop device that is
currently under exclusively ownership/open
- Set chunk sectors from stacked device stripe size and use it for the
atomic write size limit
- Switch to folios in bcache read_super()
- Fix for CD-ROM MRW exit flush handling
- Various tweaks, fixes, and cleanups
* tag 'for-6.17/block-20250728' of git://git.kernel.dk/linux: (94 commits)
block: restore two stage elevator switch while running nr_hw_queue update
cdrom: Call cdrom_mrw_exit from cdrom_release function
sunvdc: Balance device refcount in vdc_port_mpgroup_check
nvme-pci: try function level reset on init failure
dm: split write BIOs on zone boundaries when zone append is not emulated
block: use chunk_sectors when evaluating stacked atomic write limits
dm-stripe: limit chunk_sectors to the stripe size
md/raid10: set chunk_sectors limit
md/raid0: set chunk_sectors limit
block: sanitize chunk_sectors for atomic write limits
ilog2: add max_pow_of_two_factor()
nvmet: pci-epf: Do not complete commands twice if nvmet_req_init() fails
nvme-tcp: log TLS handshake failures at error level
docs: nvme: fix grammar in nvme-pci-endpoint-target.rst
nvme: fix typo in status code constant for self-test in progress
nvmet: remove redundant assignment of error code in nvmet_ns_enable()
nvme: fix incorrect variable in io cqes error message
nvme: fix multiple spelling and grammar issues in host drivers
block: fix blk_zone_append_update_request_bio() kernel-doc
md/raid10: fix set but not used variable in sync_request_write()
...
Add a per-cpu monitor as part of the sched model:
* opid: operations with preemption and irq disabled
Monitor to ensure wakeup and need_resched occur with irq and
preemption disabled or in irq handlers.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20250728135022.255578-10-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Acked-by: Nam Cao <namcao@linutronix.de>
Tested-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add 2 per-task monitors as part of the sched model:
* nrp: need-resched preempts
Monitor to ensure preemption requires need resched.
* sssw: set state sleep and wakeup
Monitor to ensure sched_set_state to sleepable leads to sleeping and
sleeping tasks require wakeup.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20250728135022.255578-9-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Acked-by: Nam Cao <namcao@linutronix.de>
Tested-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The tss monitor currently guarantees task switches can happen only while
scheduling, whereas the sncid monitor enforces scheduling occurs with
interrupt disabled.
Replace the monitors with a more comprehensive specification which
implies both but also ensures that:
* each scheduler call disable interrupts to switch
* each task switch happens with interrupts disabled
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nam Cao <namcao@linutronix.de>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20250728135022.255578-8-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add the following tracepoint:
* sched_set_need_resched(tsk, cpu, tif)
Called when a task is set the need resched [lazy] flag
Remove the unused ip parameter from sched_entry and sched_exit and alter
sched_entry to have a value of preempt consistent with the one used in
sched_switch.
Also adapt all monitors using sched_{entry,exit} to avoid breaking build.
These tracepoints are useful to describe the Linux task model and are
adapted from the patches by Daniel Bristot de Oliveira
(https://bristot.me/linux-task-model/).
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Nam Cao <namcao@linutronix.de>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20250728135022.255578-7-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
DA monitor can be accessed from multiple cores simultaneously, this is
likely, for instance when dealing with per-task monitors reacting on
events that do not always occur on the CPU where the task is running.
This can cause race conditions where two events change the next state
and we see inconsistent values. E.g.:
[62] event_srs: 27: sleepable x sched_wakeup -> running (final)
[63] event_srs: 27: sleepable x sched_set_state_sleepable -> sleepable
[63] error_srs: 27: event sched_switch_suspend not expected in the state running
In this case the monitor fails because the event on CPU 62 wins against
the one on CPU 63, although the correct state should have been
sleepable, since the task get suspended.
Detect if the current state was modified by using try_cmpxchg while
storing the next value. If it was, try again reading the current state.
After a maximum number of failed retries, react by calling a special
tracepoint, print on the console and reset the monitor.
Remove the functions da_monitor_curr_state() and da_monitor_set_state()
as they only hide the underlying implementation in this case.
Monitors where this type of condition can occur must be able to account
for racing events in any possible order, as we cannot know the winner.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20250728135022.255578-6-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Reviewed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
RV monitors relying on the preemptirqs tracepoints are set as dependent
on PREEMPT_TRACER and IRQSOFF_TRACER. In fact, those configurations do
enable the tracepoints but are not the minimal configurations enabling
them, which are TRACE_PREEMPT_TOGGLE and TRACE_IRQFLAGS (not selectable
manually).
Set TRACE_PREEMPT_TOGGLE and TRACE_IRQFLAGS as dependencies for
monitors.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20250728135022.255578-5-gmonaco@redhat.com
Fixes: fbe6c09b7e ("rv: Add scpd, snep and sncid per-cpu monitors")
Acked-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Using DA monitors tracepoints with KASAN enabled triggers the following
warning:
BUG: KASAN: global-out-of-bounds in do_trace_event_raw_event_event_da_monitor+0xd6/0x1a0
Read of size 32 at addr ffffffffaada8980 by task ...
Call Trace:
<TASK>
[...]
do_trace_event_raw_event_event_da_monitor+0xd6/0x1a0
? __pfx_do_trace_event_raw_event_event_da_monitor+0x10/0x10
? trace_event_sncid+0x83/0x200
trace_event_sncid+0x163/0x200
[...]
The buggy address belongs to the variable:
automaton_snep+0x4e0/0x5e0
This is caused by the tracepoints reading 32 bytes __array instead of
__string from the automata definition. Such strings are literals and
reading 32 bytes ends up in out of bound memory accesses (e.g. the next
automaton's data in this case).
The error is harmless as, while printing the string, we stop at the null
terminator, but it should still be fixed.
Use the __string facilities while defining the tracepoints to avoid
reading out of bound memory.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20250728135022.255578-4-gmonaco@redhat.com
Fixes: 792575348f ("rv/include: Add deterministic automata monitor definition via C macros")
Reviewed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
RV event tracepoints print a line with the format:
"event_xyz: S0 x event -> S1 "
"event_xyz: S1 x event -> S0 (final)"
While printing an event leading to a non-final state, the line
has a trailing white space (visible above before the closing ").
Adapt the format string not to print the trailing whitespace if we are
not printing "(final)".
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20250728135022.255578-3-gmonaco@redhat.com
Reviewed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Argument 'p' of reactors_show() and monitor_reactor_show() is not a pointer
to struct rv_reactor, it is actually a pointer to the list_head inside
struct rv_reactor. Therefore it's wrong to cast 'p' to struct rv_reactor *.
This wrong type cast has been there since the beginning. But it still
worked because the list_head was the first field in struct rv_reactor_def.
This is no longer true since commit 3d3c376118 ("rv: Merge struct
rv_reactor_def into struct rv_reactor") moved the list_head, and this wrong
type cast became a functional problem.
Properly use container_of() instead.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/b4febbd6844311209e4c8768b65d508b81bd8c9b.1753625621.git.namcao@linutronix.de
Fixes: 3d3c376118 ("rv: Merge struct rv_reactor_def into struct rv_reactor")
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Argument 'p' of monitors_show() is not a pointer to struct rv_monitor, it
is actually a pointer to the list_head inside struct rv_monitor. Therefore
it is wrong to cast 'p' to struct rv_monitor *.
This wrong type cast has been there since the beginning. But it still
worked because the list_head was the first field in struct rv_monitor_def.
This is no longer true since commit 24cbfe18d5 ("rv: Merge struct
rv_monitor_def into struct rv_monitor") moved the list_head, and this wrong
type cast became a functional problem.
Properly use container_of() instead.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/35e49e97696007919ceacf73796487a2e15a3d02.1753625621.git.namcao@linutronix.de
Fixes: 24cbfe18d5 ("rv: Merge struct rv_monitor_def into struct rv_monitor")
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The field 'reacting' in struct rv_monitor is set but never used. Delete it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/a6c16f845d2f1a09c4d0934ab83f3cb14478a71d.1753378331.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
rv_reactor has a reference counter to ensure it is not removed while
monitors are still using it.
However, this is futile, as __exit functions are not expected to fail and
will proceed normally despite rv_unregister_reactor() returning an error.
At the moment, reactors do not support being built as modules, therefore
they are never removed and the reference counters are not necessary.
If we support building RV reactors as modules in the future, kernel
module's centralized facilities such as try_module_get(), module_put() or
MODULE_SOFTDEP should be used instead of this custom implementation.
Remove this reference counter.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/bb946398436a5e17fb0f5b842ef3313c02291852.1753378331.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Each struct rv_reactor has a unique struct rv_reactor_def associated with
it. struct rv_reactor is statically allocated, while struct rv_reactor_def
is dynamically allocated.
This makes the code more complicated than it should be:
- Lookup is required to get the associated rv_reactor_def from rv_reactor
- Dynamic memory allocation is required for rv_reactor_def. This is
harder to get right compared to static memory. For instance, there is
an existing mistake: rv_unregister_reactor() does not free the memory
allocated by rv_register_reactor(). This is fortunately not a real
memory leak problem as rv_unregister_reactor() is never called.
Simplify and merge rv_reactor_def into rv_reactor.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/71cb91c86cd40df5b8c492b788787f2a73c3eaa3.1753378331.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Each struct rv_monitor has a unique struct rv_monitor_def associated with
it. struct rv_monitor is statically allocated, while struct rv_monitor_def
is dynamically allocated.
This makes the code more complicated than it should be:
- Lookup is required to get the associated rv_monitor_def from rv_monitor
- Dynamic memory allocation is required for rv_monitor_def. This is
harder to get right compared to static memory. For instance, there is
an existing mistake: rv_unregister_monitor() does not free the memory
allocated by rv_register_monitor(). This is fortunately not a real
memory leak problem, as rv_unregister_monitor() is never called.
Simplify and merge rv_monitor_def into rv_monitor.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/194449c00f87945c207aab4c96920c75796a4f53.1753378331.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
rv_monitor_def::task_monitor is not used. Delete it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/502d94f2696435690a2b1fdbe80a9e56c96fcabf.1753378331.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The trace event filter bootup self test tests a bunch of filter logic
against the ftrace_test_filter event, but does not actually call the
event. Work is being done to cause a warning if an event is defined but
not used. To quiet the warning call the trace event under an if statement
where it is disabled so it doesn't get optimized out.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas.schier@linux.dev>
Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20250723194212.274458858@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Monitors generated with dot2k have their registration function (the one
called during monitor initialisation) return always 0, even if the
registration failed on RV side.
This can hide potential errors.
Return the value returned by the RV register function.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20250723161240.194860-6-gmonaco@redhat.com
Reviewed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The current behaviour of rvgen when running with the -a option is to
append the necessary lines at the end of the configuration for Kconfig,
Makefile and tracepoints.
This is not always the desired behaviour in case of nested monitors:
while tracepoints are not affected by nesting and the Makefile's only
requirement is that the parent monitor is built before its children, in
the Kconfig it is better to have children defined right after their
parent, otherwise the result has wrong indentation:
[*] foo_parent monitor
[*] foo_child1 monitor
[*] foo_child2 monitor
[*] bar_parent monitor
[*] bar_child1 monitor
[*] bar_child2 monitor
[*] foo_child3 monitor
[*] foo_child4 monitor
Adapt rvgen to look for a different marker for nested monitors in the
Kconfig file and append the line right after the last sibling, instead
of the last monitor.
Also add the marker when creating a new parent monitor.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20250723161240.194860-5-gmonaco@redhat.com
Reviewed-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The dot2c.py script generates all states in a single line. This breaks the
100 column limit when the state machines are non-trivial.
Change dot2c.py to generate the states in separate lines in case the
generated line is going to be too long.
Also adapt existing monitors with line length over the limit.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Juri Lelli <jlelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20250723161240.194860-4-gmonaco@redhat.com
Suggested-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
eprobes are dynamic events that can read other events using their fields
to create new events. Currently it doesn't work with arrays. When the new
event field is attached to the old event field, it looks at the size of
the field to determine what type of field the new field should be. For 1
byte fields it's a char, for 2 bytes, it's a short and for 4 bytes it's an
integer. For all other sizes it just defaults to "long". This also reads
the contents of the field for such cases.
For arrays that are bigger than the size of long, return the value of the
address of the content itself. This will allow eprobes to read other
values in the array of the old event.
This is useful when raw_syscalls is enabled but the syscall events are
not. The syscall events are created from the raw_syscalls as they have an
array of "args" that holds the 6 long words passed to the syscall entry
point. To read the value of "filename" from sys_openat, the eprobe could
attach to the raw_syscall and read the second value.
It can then even be passed to a synthetic event and converted back to
another eprobe to get the value of "filename" after it has been read by
the kernel during the system call:
[
Create an eprobe called "sys" and attach it to sys_enter.
Read the id of the system call and the second argument
]
# echo 'e:sys raw_syscalls.sys_enter nr=$id:u32 arg2=+8($args):u64' >> /sys/kernel/tracing/dynamic_events
[
Create a synthetic event "path" that will hold the address of the
sys_openat filename. This is on a 64bit machine, so make it 64 bits
]
# echo 's:path u64 file;' >> /sys/kernel/tracing/dynamic_events
[
Add a histogram to the eprobe/sys which tiggers if the "nr" field is
257 (sys_openat), and save the filename in the "file" variable.
]
# echo 'hist:keys=common_pid:file=arg2 if nr == 257' > /sys/kernel/tracing/events/eprobes/sys/trigger
[
Attach a histogram to sys_exit event that triggers the "path" synthetic
event and records the "filename" that was passed from the sys eprobe.
]
# echo 'hist:keys=common_pid:f=$file:onmatch(eprobes.sys).trace(path,$f)' >> /sys/kernel/tracing/events/raw_syscalls/sys_exit/trigger
[
Create another eprobe that dereferences the "file" field as a user
space string and displays it.
]
# echo 'e:open synthetic.path file=+0($file):ustring' >> /sys/kernel/tracing/dynamic_events
# echo 1 > /sys/kernel/tracing/events/eprobes/open/enable
# cat trace_pipe
cat-1142 [003] ...5. 799.521912: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.521934: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522065: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522080: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522296: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
cat-1142 [003] ...5. 799.522319: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
less-1143 [005] ...5. 799.522327: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522333: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
cat-1142 [003] ...5. 799.522348: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
less-1143 [005] ...5. 799.522349: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522363: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
less-1143 [005] ...5. 799.522477: open: (synthetic.path) file="/etc/ld.so.cache"
cat-1142 [003] ...5. 799.522489: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
less-1143 [005] ...5. 799.522492: open: (synthetic.path) file="/etc/ld.so.cache"
less-1143 [005] ...5. 799.522720: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libtinfo.so.6"
less-1143 [005] ...5. 799.522744: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libtinfo.so.6"
less-1143 [005] ...5. 799.522759: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libtinfo.so.6"
cat-1142 [003] ...5. 799.522850: open: (synthetic.path) file="/lib/x86_64-linux-gnu/libc.so.6"
Link: https://lore.kernel.org/all/20250723124202.4f7475be@batman.local.home/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
The ipi tracepoints are mostly generic, but the tracepoints ipi_raise,
ipi_entry and ipi_exit are only used by arm and arm64. This means these
trace events are wasting memory in all the other architectures that do not
use them.
Add CONFIG_HAVE_EXTRA_IPI_TRACEPOINTS and have arm and arm64 select it to
enable these trace events. The config makes it easy if other architectures
decide to trace these as well.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Will Deacon <will@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/20250722103714.64eba013@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Since traceprobe_parse_event_name() is a bit complicated, add a
kerneldoc for explaining the behavior.
Link: https://lore.kernel.org/all/175323430565.57270.2602609519355112748.stgit@devnote2/
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Sort the #include directives in trace_probe* files alphabetically for
easier maintenance and avoid double includes.
This also groups headers as linux-generic, asm-generic, and local
headers.
Link: https://lore.kernel.org/all/175323424678.57270.11975372127870059007.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
In January 2015, tracefs was created to allow access to the tracing
infrastructure without needing to compile in debugfs. When tracefs is
configured, the directory /sys/kernel/tracing will exist and tooling is
expected to use that path to access the tracing infrastructure.
To allow backward compatibility, when debugfs is mounted, it would
automount tracefs in its "tracing" directory so that tooling that had hard
coded /sys/kernel/debug/tracing would still work.
It has been over 10 years since the new interface was introduced, and all
tooling should now be using it. Start the process of deprecating the old
path so that it doesn't need to be maintained anymore.
A new config is added to allow distributions to disable automounting of
tracefs on debugfs.
If /sys/kernel/debug/tracing is accessed, a pr_warn() will trigger stating:
"NOTICE: Automounting of tracing to debugfs is deprecated and will be removed in 2030"
Expect to remove this feature in 5 years (2030).
Cc: <linux-trace-users@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/20250722170806.40c068c6@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Ftrace is tightly coupled with architecture specific code because it
requires the use of trampolines written in assembly. This means that when
a new feature or optimization is made, it must be done for all
architectures. To simplify the approach, CONFIG_HAVE_FTRACE_* configs are
added to denote which architecture has the new enhancement so that other
architectures can still function until they too have been updated.
The CONFIG_HAVE_FTRACE_MCOUNT was added to help simplify the
DYNAMIC_FTRACE work, but now every architecture that implements
DYNAMIC_FTRACE also has HAVE_FTRACE_MCOUNT set too, making it redundant
with the HAVE_DYNAMIC_FTRACE.
Remove the HAVE_FTRACE_MCOUNT config and use DYNAMIC_FTRACE directly where
applicable.
Link: https://lore.kernel.org/all/20250703154916.48e3ada7@gandalf.local.home/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20250704104838.27a18690@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When soft disabling of trace events was first created, it needed to have a
way to know if a file had a user that was using it with soft disabled (for
triggers that need to enable or disable events from a context that can not
really enable or disable the event, it would set SOFT_DISABLED to state it
is disabled). The flag SOFT_MODE was used to denote that an event had a
user that would enable or disable it via the SOFT_DISABLED flag.
Commit 1cf4c0732d ("tracing: Modify soft-mode only if there's no other
referrer") fixed a bug where if two users were using the SOFT_DISABLED
flag the accounting would get messed up as the SOFT_MODE flag could only
handle one user. That commit added the sm_ref counter which kept track of
how many users were using the event in "soft mode". This made the
SOFT_MODE flag redundant as it should only be set if the sm_ref counter is
non zero.
Remove the SOFT_MODE flag and just use the sm_ref counter to know the
event is in soft mode or not. This makes the code a bit simpler.
Link: https://lore.kernel.org/all/20250702111908.03759998@batman.local.home/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Link: https://lore.kernel.org/20250702143657.18dd1882@batman.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Memory barriers are useful to ensure memory accesses from one CPU appear in
the original order as seen by other CPUs.
Some smp_rmb() and smp_wmb() are used, but they are not ordering multiple
memory accesses.
Remove them.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/20250626151940.1756398-1-namcao@linutronix.de
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
ftrace has two flavors:
1) static: Where every function always calls the ftrace trampoline
2) dynamic: Where each function has nops that can be changed on demand to
jump to the ftrace trampoline when needed.
The static flavor has very high performance overhead and was only created
to make it easier for architectures to implement the dynamic flavor. An
architecture developer can first implement the static ftrace to make sure
the trampolines work before working on the more complicated dynamic aspect
of ftrace. Once the architecture can support dynamic ftrace, there's no
reason to continue to support the static flavor. In fact, the static
flavor tends to bitrot and bugs start to appear in them.
Remove the prompt to pick DYNAMIC_FTRACE and simply enable it if the
architecture supports it.
Link: https://lore.kernel.org/all/f7e12c6d-892e-4ca3-9ef0-fbb524d04a48@ghiti.fr/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: ChenMiao <chenmiao.ku@gmail.com>
Link: https://lore.kernel.org/20250703115222.2d7c8cd5@batman.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add a warning if unregister_ftrace_graph() is called without ever
registering it, or if register_ftrace_graph() is called twice. This can
detect errors when they happen and not later when there's a side effect:
Link: https://lore.kernel.org/all/20250617120830.24fbdd62@gandalf.local.home/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/20250701194451.22e34724@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When the ring buffer was first introduced, reading the non-consuming
"trace" file required disabling the writing of the ring buffer. To make
sure the writing was fully disabled before iterating the buffer with a
non-consuming read, it would set the disable flag of the buffer and then
call an RCU synchronization to make sure all the buffers were
synchronized.
The function ring_buffer_read_start() originally would initialize the
iterator and call an RCU synchronization, but this was for each individual
per CPU buffer where this would get called many times on a machine with
many CPUs before the trace file could be read. The commit 72c9ddfd4c
("ring-buffer: Make non-consuming read less expensive with lots of cpus.")
separated ring_buffer_read_start into ring_buffer_read_prepare(),
ring_buffer_read_sync() and then ring_buffer_read_start() to allow each of
the per CPU buffers to be prepared, call the read_buffer_read_sync() once,
and then the ring_buffer_read_start() for each of the CPUs which made
things much faster.
The commit 1039221cc2 ("ring-buffer: Do not disable recording when there
is an iterator") removed the requirement of disabling the recording of the
ring buffer in order to iterate it, but it did not remove the
synchronization that was happening that was required to wait for all the
buffers to have no more writers. It's now OK for the buffers to have
writers and no synchronization is needed.
Remove the synchronization and put back the interface for the ring buffer
iterator back before commit 72c9ddfd4c was applied.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250630180440.3eabb514@batman.local.home
Reported-by: David Howells <dhowells@redhat.com>
Fixes: 1039221cc2 ("ring-buffer: Do not disable recording when there is an iterator")
Tested-by: David Howells <dhowells@redhat.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
As the trace event powernv_throttle is only used by the powernv code, move
it to a separate include file and have that code directly enable it.
Trace events can take up around 5K of memory when they are defined
regardless if they are used or not. It wastes memory to have them defined
in configurations where the tracepoint is not used.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/20250612145407.906308844@goodmis.org
Fixes: 0306e481d4 ("cpufreq: powernv/tracing: Add powernv_throttle tracepoint")
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Fix timerlat with use of FORTIFY_SOURCE
FORTIFY_SOURCE was added to the stack tracer where it compares the
entry->caller array to having entry->size elements.
timerlat has the following:
memcpy(&entry->caller, fstack->calls, size);
entry->size = size;
Which triggers FORTIFY_SOURCE as the caller is populated before the
entry->size is initialized.
Swap the order to satisfy FORTIFY_SOURCE logic.
- Add down_write(trace_event_sem) when adding trace events in modules
Trace events being added to the ftrace_events array are protected by
the trace_event_sem semaphore. But when loading modules that have
trace events, the addition of the events are not protected by the
semaphore and loading two modules that have events at the same time
can corrupt the list.
Also add a lockdep_assert_held(trace_event_sem) to
_trace_add_event_dirs() to confirm its held when iterating the list.
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Merge tag 'trace-v6.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix timerlat with use of FORTIFY_SOURCE
FORTIFY_SOURCE was added to the stack tracer where it compares the
entry->caller array to having entry->size elements.
timerlat has the following:
memcpy(&entry->caller, fstack->calls, size);
entry->size = size;
Which triggers FORTIFY_SOURCE as the caller is populated before the
entry->size is initialized.
Swap the order to satisfy FORTIFY_SOURCE logic.
- Add down_write(trace_event_sem) when adding trace events in modules
Trace events being added to the ftrace_events array are protected by
the trace_event_sem semaphore. But when loading modules that have
trace events, the addition of the events are not protected by the
semaphore and loading two modules that have events at the same time
can corrupt the list.
Also add a lockdep_assert_held(trace_event_sem) to
_trace_add_event_dirs() to confirm it is held when iterating the
list.
* tag 'trace-v6.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Add down_write(trace_event_sem) when adding trace event
tracing/osnoise: Fix crash in timerlat_dump_stack()
When a module is loaded, it adds trace events defined by the module. It
may also need to modify the modules trace printk formats to replace enum
names with their values.
If two modules are loaded at the same time, the adding of the event to the
ftrace_events list can corrupt the walking of the list in the code that is
modifying the printk format strings and crash the kernel.
The addition of the event should take the trace_event_sem for write while
it adds the new event.
Also add a lockdep_assert_held() on that semaphore in
__trace_add_event_dirs() as it iterates the list.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/20250718223158.799bfc0c@batman.local.home
Reported-by: Fusheng Huang(黄富生) <Fusheng.Huang@luxshare-ict.com>
Closes: https://lore.kernel.org/all/20250717105007.46ccd18f@batman.local.home/
Fixes: 110bf2b764 ("tracing: add protection around module events unload")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
We have observed kernel panics when using timerlat with stack saving,
with the following dmesg output:
memcpy: detected buffer overflow: 88 byte write of buffer size 0
WARNING: CPU: 2 PID: 8153 at lib/string_helpers.c:1032 __fortify_report+0x55/0xa0
CPU: 2 UID: 0 PID: 8153 Comm: timerlatu/2 Kdump: loaded Not tainted 6.15.3-200.fc42.x86_64 #1 PREEMPT(lazy)
Call Trace:
<TASK>
? trace_buffer_lock_reserve+0x2a/0x60
__fortify_panic+0xd/0xf
__timerlat_dump_stack.cold+0xd/0xd
timerlat_dump_stack.part.0+0x47/0x80
timerlat_fd_read+0x36d/0x390
vfs_read+0xe2/0x390
? syscall_exit_to_user_mode+0x1d5/0x210
ksys_read+0x73/0xe0
do_syscall_64+0x7b/0x160
? exc_page_fault+0x7e/0x1a0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
__timerlat_dump_stack() constructs the ftrace stack entry like this:
struct stack_entry *entry;
...
memcpy(&entry->caller, fstack->calls, size);
entry->size = fstack->nr_entries;
Since commit e7186af7fb ("tracing: Add back FORTIFY_SOURCE logic to
kernel_stack event structure"), struct stack_entry marks its caller
field with __counted_by(size). At the time of the memcpy, entry->size
contains garbage from the ringbuffer, which under some circumstances is
zero, triggering a kernel panic by buffer overflow.
Populate the size field before the memcpy so that the out-of-bounds
check knows the correct size. This is analogous to
__ftrace_trace_stack().
Cc: stable@vger.kernel.org
Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Cc: Attila Fazekas <afazekas@redhat.com>
Link: https://lore.kernel.org/20250716143601.7313-1-tglozar@redhat.com
Fixes: e7186af7fb ("tracing: Add back FORTIFY_SOURCE logic to kernel_stack event structure")
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
After a recent change in clang to strengthen uninitialized warnings [1],
it points out that in one of the error paths in parse_btf_arg(), params
is used uninitialized:
kernel/trace/trace_probe.c:660:19: warning: variable 'params' is uninitialized when used here [-Wuninitialized]
660 | return PTR_ERR(params);
| ^~~~~~
Match many other NO_BTF_ENTRY error cases and return -ENOENT, clearing
up the warning.
Link: https://lore.kernel.org/all/20250715-trace_probe-fix-const-uninit-warning-v1-1-98960f91dd04@kernel.org/
Cc: stable@vger.kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/2110
Fixes: d157d76944 ("tracing/probes: Support BTF field access from $retval")
Link: 2464313eef [1]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Add zoned block commands to blk_fill_rwbs:
- ZONE APPEND will be decoded as 'ZA'
- ZONE RESET will be decoded as 'ZR'
- ZONE RESET ALL will be decoded as 'ZRA'
- ZONE FINISH will be decoded as 'ZF'
- ZONE OPEN will be decoded as 'ZO'
- ZONE CLOSE will be decoded as 'ZC'
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250715115324.53308-2-johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Attach_type will be set when a link is created by user. It is better to
record attach_type in bpf_link generically and have it available
universally for all link types. So add the attach_type field in bpf_link
and move the sleepable field to avoid unnecessary gap padding.
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20250710032038.888700-2-chen.dylane@linux.dev
Replace internal subbuf_start in blktrace with the default policy in
relayfs.
Remove dropped field from struct blktrace. Correspondingly, call the
common helper in relay. By incrementing full_count to keep track of how
many times we encountered a full buffer issue, user space will know how
many events were lost.
Link: https://lkml.kernel.org/r/20250612061201.34272-5-kerneljasonxing@gmail.com
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Yushan Zhou <katrinzhou@tencent.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "relayfs: misc changes", v5.
The series mostly focuses on the error counters which helps every user
debug their own kernel module.
This patch (of 5):
prev_padding represents the unused space of certain subbuffer. If the
content of a call of relay_write() exceeds the limit of the remainder of
this subbuffer, it will skip storing in the rest space and record the
start point as buf->prev_padding in relay_switch_subbuf(). Since the buf
is a per-cpu big buffer, the point of prev_padding as a global value for
the whole buffer instead of a single subbuffer (whose padding info is
stored in buf->padding[]) seems meaningless from the real use cases, so we
don't bother to record it any more.
Link: https://lkml.kernel.org/r/20250612061201.34272-1-kerneljasonxing@gmail.com
Link: https://lkml.kernel.org/r/20250612061201.34272-2-kerneljasonxing@gmail.com
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Yushan Zhou <katrinzhou@tencent.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The comment above buffer mentions sign, 10 bytes width for number and null
terminator, but buffer itself isn't large enough to hold that much data.
This is a cosmetic change, since PID cannot be negative, other than -1.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Link: https://lore.kernel.org/20250617152110.2530-1-a.sadovnikov@ispras.ru
Signed-off-by: Artem Sadovnikov <a.sadovnikov@ispras.ru>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Rewind persistent ring buffer pages which have been read in the previous
boot. Those pages are highly possible to be lost before writing it to the
disk if the previous kernel crashed. In this case, the trace data is kept
on the persistent ring buffer, but it can not be read because its commit
size has been reset after read. This skips clearing the commit size of
each sub-buffer and recover it after reboot.
Note: If you read the previous boot data via trace_pipe, that is not
accessible in that time. But reboot without clearing (or reusing) the read
data, the read data is recovered again in the next boot.
Thus, when you read the previous boot data, clear it by `echo > trace`.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/174899582116.955054.773265393511190051.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Now that there are 2 monitors for real-time applications, users may want to
enable both of them simultaneously. Make the number of per-task monitor
configurable. Default it to 2 for now.
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/93e83313fc4ba7f6e66f4abe80ca5f5494d658d0.1752088709.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add a monitor for checking that real-time tasks do not go to sleep in a
manner that may cause undesirable latency.
Also change
RV depends on TRACING
to
RV select TRACING
to avoid the following recursive dependency:
error: recursive dependency detected!
symbol TRACING is selected by PREEMPTIRQ_TRACEPOINTS
symbol PREEMPTIRQ_TRACEPOINTS depends on TRACE_IRQFLAGS
symbol TRACE_IRQFLAGS is selected by RV_MON_SLEEP
symbol RV_MON_SLEEP depends on RV
symbol RV depends on TRACING
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/75bc5bcc741d153aa279c95faf778dff35c5c8ad.1752088709.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Userspace real-time applications may have design flaws that they raise
page faults in real-time threads, and thus have unexpected latencies.
Add an linear temporal logic monitor to detect this scenario.
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/78fea8a2de6d058241d3c6502c1a92910772b0ed.1752088709.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add the container "rtapp" which is the monitor collection for detecting
problems with real-time applications. The monitors will be added in the
follow-up commits.
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/fb18b87631d386271de00959d8d4826f23fcd1cd.1752088709.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
While attempting to implement DA monitors for some complex specifications,
deterministic automaton is found to be inappropriate as the specification
language. The automaton is complicated, hard to understand, and
error-prone.
For these cases, linear temporal logic is more suitable as the
specification language.
Add support for linear temporal logic runtime verification monitor.
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/d366c1fed60ed4e8f6451f3c15a99755f2740b5f.1752088709.git.namcao@linutronix.de
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
CONFIG_DA_MON_EVENTS is not specific to deterministic automaton. It could
be used for other monitor types. Therefore rename it to
CONFIG_RV_MON_EVENTS.
This prepares for the introduction of linear temporal logic monitor.
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/507210517123d887c1d208aa2fd45ec69765d3f0.1752088709.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Each RV monitor has one static buffer to send to the reactors. If multiple
errors are detected simultaneously, the one buffer could be overwritten.
Instead, leave it to the reactors to handle buffering.
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Without "#undef TRACE_INCLUDE_FILE", there could be a build error due to
TRACE_INCLUDE_FILE being redefined. Therefore add it.
Also fix a typo while at it.
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/f805e074581e927bb176c742c981fa7675b6ebe5.1752088709.git.namcao@linutronix.de
Reviewed-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
A CPU mask on the stack is broken for large values of CONFIG_NR_CPUS:
kernel/trace/preemptirq_delay_test.c: In function ‘preemptirq_delay_run’:
kernel/trace/preemptirq_delay_test.c:143:1: error: the frame size of 8512 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
Fall back to dynamic allocation here.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Song Chen <chensong_2000@189.cn>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250620111215.3365305-1-arnd@kernel.org
Fixes: 4b9091e1c1 ("kernel: trace: preemptirq_delay_test: add cpu affinity")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Freeing of filters requires to wait for both an RCU grace period as well as
a RCU task trace wait period after they have been detached from their
lists. The trace task period can be quite large so the freeing of the
filters was moved to use the call_rcu*() routines. The problem with that is
that the callback functions of call_rcu*() is done from a soft irq and can
cause latencies if the callback takes a bit of time.
The filters are freed per event in a system and the syscalls system
contains an event per system call, which can be over 700 events. Freeing 700
filters in a bottom half is undesirable.
Instead, move the freeing to use queue_rcu_work() which is done in task
context.
Link: https://lore.kernel.org/all/9a2f0cd0-1561-4206-8966-f93ccd25927f@paulmck-laptop/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250609131732.04fd303b@gandalf.local.home
Fixes: a9d0aab5eb ("tracing: Fix regression of filter waiting a long time on RCU synchronization")
Suggested-by: "Paul E. McKenney" <paulmck@kernel.org>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The dedicated cpumask_next_wrap() is more verbose and effective than
cpumask_next() followed by cpumask_first().
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250605000651.45281-1-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Alexei suggested, 'link_type' can be more precise and differentiate
for human in fdinfo. In fact BPF_LINK_TYPE_KPROBE_MULTI includes
kretprobe_multi type, the same as BPF_LINK_TYPE_UPROBE_MULTI, so we
can show it more concretely.
link_type: kprobe_multi
link_id: 1
prog_tag: d2b307e915f0dd37
...
link_type: kretprobe_multi
link_id: 2
prog_tag: ab9ea0545870781d
...
link_type: uprobe_multi
link_id: 9
prog_tag: e729f789e34a8eca
...
link_type: uretprobe_multi
link_id: 10
prog_tag: 7db356c03e61a4d4
Co-developed-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Link: https://lore.kernel.org/r/20250702153958.639852-1-chen.dylane@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
As same as fprobe, register tracepoint stub function only when enabling
tprobe events. The major changes are introducing a list of
tracepoint_user and its lock, and tprobe_event_module_nb, which is
another module notifier for module loading/unloading. By spliting the
lock from event_mutex and a module notifier for trace_fprobe, it
solved AB-BA lock dependency issue between event_mutex and
tracepoint_module_list_mutex.
Link: https://lore.kernel.org/all/174343538901.843280.423773753642677941.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Currently fprobe events are registered when it is defined. Thus it will
give some overhead even if it is disabled. This changes it to register the
fprobe only when it is enabled.
Link: https://lore.kernel.org/all/174343537128.843280.16131300052837035043.stgit@devnote2/
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cleanup __store_entry_arg() so that it is easier to understand.
The main complexity may come from combining the loops for finding
stored-entry-arg and max-offset and appending new entry.
This split those different loops into 3 parts, lookup the same
entry-arg, find the max offset and append new entry.
Link: https://lore.kernel.org/all/174323039929.348535.4705349977127704120.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cross-merge BPF, perf and other fixes after downstream PRs.
It restores BPF CI to green after critical fix
commit bc4394e5e7 ("perf: Fix the throttle error of some clock events")
No conflicts.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The underlying lookup_user_key() function uses a signed 32 bit integer
for key serial numbers because legitimate serial numbers are positive
(and > 3) and keyrings are negative. Using a u32 for the keyring in
the bpf function doesn't currently cause any conversion problems but
will start to trip the signed to unsigned conversion warnings when the
kernel enables them, so convert the argument to signed (and update the
tests accordingly) before it acquires more users.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Link: https://lore.kernel.org/r/84cdb0775254d297d75e21f577089f64abdfbd28.camel@HansenPartnership.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The variable "head" is allocated and initialized as a list before
allocating the first "item" for the list. If the allocation of "item"
fails, it frees "head" and then jumps to the label "free_now" which will
process head and free it.
This will cause a UAF of "head", and it doesn't need to free it before
jumping to the "free_now" label as that code will free it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250610093348.33c5643a@gandalf.local.home
Fixes: a9d0aab5eb ("tracing: Fix regression of filter waiting a long time on RCU synchronization")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202506070424.lCiNreTI-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Fix regression of waiting a long time on updating trace event filters
When the faultable trace points were added, it needed task trace RCU
synchronization. This was added to the tracepoint_synchronize_unregister()
function. The filter logic always called this function whenever it
updated the trace event filters before freeing the old filters.
This increased the time of "trace-cmd record" from taking 13 seconds
to running over 2 minutes to complete.
Move the freeing of the filters to call_rcu*() logic, which brings the
time back down to 13 seconds.
- Fix ring_buffer_subbuf_order_set() error path lock protection
The error path of the ring_buffer_subbuf_order_set() released the
mutex too early and allowed subsequent accesses to setting the
subbuffer size to corrupt the data and cause a bug.
By moving the mutex locking to the end of the error path, it prevents
the reentrant access to the critical data and also allows the function
to convert the taking of the mutex over to the guard() logic.
- Remove unused power management clock events
The clock events were added in 2010 for power management. In 2011
arm used them. In 2013 the code they were used in was removed.
These events have been wasting memory since then.
- Fix sparse warnings
There was a few places that sparse warned about trace_events_filter.c
where file->filter was referenced directly, but it is annotated with
an __rcu tag. Use the helper functions and fix them up to use
rcu_dereference() properly.
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Merge tag 'trace-v6.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull more tracing fixes from Steven Rostedt:
- Fix regression of waiting a long time on updating trace event filters
When the faultable trace points were added, it needed task trace RCU
synchronization.
This was added to the tracepoint_synchronize_unregister() function.
The filter logic always called this function whenever it updated the
trace event filters before freeing the old filters. This increased
the time of "trace-cmd record" from taking 13 seconds to running over
2 minutes to complete.
Move the freeing of the filters to call_rcu*() logic, which brings
the time back down to 13 seconds.
- Fix ring_buffer_subbuf_order_set() error path lock protection
The error path of the ring_buffer_subbuf_order_set() released the
mutex too early and allowed subsequent accesses to setting the
subbuffer size to corrupt the data and cause a bug.
By moving the mutex locking to the end of the error path, it prevents
the reentrant access to the critical data and also allows the
function to convert the taking of the mutex over to the guard()
logic.
- Remove unused power management clock events
The clock events were added in 2010 for power management. In 2011 arm
used them. In 2013 the code they were used in was removed. These
events have been wasting memory since then.
- Fix sparse warnings
There was a few places that sparse warned about trace_events_filter.c
where file->filter was referenced directly, but it is annotated with
an __rcu tag. Use the helper functions and fix them up to use
rcu_dereference() properly.
* tag 'trace-v6.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Add rcu annotation around file->filter accesses
tracing: PM: Remove unused clock events
ring-buffer: Fix buffer locking in ring_buffer_subbuf_order_set()
tracing: Fix regression of filter waiting a long time on RCU synchronization
Running sparse on trace_events_filter.c triggered several warnings about
file->filter being accessed directly even though it's annotated with __rcu.
Add rcu_dereference() around it and shuffle the logic slightly so that
it's always referenced via accessor functions.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250607102821.6c7effbf@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
* Support for the FWFT SBI extension, which is part of SBI 3.0 and a
dependency for many new SBI and ISA extensions.
* Support for getrandom() in the VDSO.
* Support for mseal.
* Optimized routines for raid6 syndrome and recovery calculations.
* kexec_file() supports loading Image-formatted kernel binaries.
* Improvements to the instruction patching framework to allow for atomic
instruction patching, along with rules as to how systems need to
behave in order to function correctly.
* Support for a handful of new ISA extensions: Svinval, Zicbop, Zabha,
some SiFive vendor extensions.
* Various fixes and cleanups, including: misaligned access handling, perf
symbol mangling, module loading, PUD THPs, and improved uaccess
routines.
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Merge tag 'riscv-for-linus-6.16-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt:
- Support for the FWFT SBI extension, which is part of SBI 3.0 and a
dependency for many new SBI and ISA extensions
- Support for getrandom() in the VDSO
- Support for mseal
- Optimized routines for raid6 syndrome and recovery calculations
- kexec_file() supports loading Image-formatted kernel binaries
- Improvements to the instruction patching framework to allow for
atomic instruction patching, along with rules as to how systems need
to behave in order to function correctly
- Support for a handful of new ISA extensions: Svinval, Zicbop, Zabha,
some SiFive vendor extensions
- Various fixes and cleanups, including: misaligned access handling,
perf symbol mangling, module loading, PUD THPs, and improved uaccess
routines
* tag 'riscv-for-linus-6.16-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (69 commits)
riscv: uaccess: Only restore the CSR_STATUS SUM bit
RISC-V: vDSO: Wire up getrandom() vDSO implementation
riscv: enable mseal sysmap for RV64
raid6: Add RISC-V SIMD syndrome and recovery calculations
riscv: mm: Add support for Svinval extension
RISC-V: Documentation: Add enough title underlines to CMODX
riscv: Improve Kconfig help for RISCV_ISA_V_PREEMPTIVE
MAINTAINERS: Update Atish's email address
riscv: uaccess: do not do misaligned accesses in get/put_user()
riscv: process: use unsigned int instead of unsigned long for put_user()
riscv: make unsafe user copy routines use existing assembly routines
riscv: hwprobe: export Zabha extension
riscv: Make regs_irqs_disabled() more clear
perf symbols: Ignore mapping symbols on riscv
RISC-V: Kconfig: Fix help text of CMDLINE_EXTEND
riscv: module: Optimize PLT/GOT entry counting
riscv: Add support for PUD THP
riscv: xchg: Prefetch the destination word for sc.w
riscv: Add ARCH_HAS_PREFETCH[W] support with Zicbop
riscv: Add support for Zicbop
...
When faultable trace events were added, a trace event may no longer use
normal RCU to synchronize but instead used synchronize_rcu_tasks_trace().
This synchronization takes a much longer time to synchronize.
The filter logic would free the filters by calling
tracepoint_synchronize_unregister() after it unhooked the filter strings
and before freeing them. With this function now calling
synchronize_rcu_tasks_trace() this increased the time to free a filter
tremendously. On a PREEMPT_RT system, it was even more noticeable.
# time trace-cmd record -p function sleep 1
[..]
real 2m29.052s
user 0m0.244s
sys 0m20.136s
As trace-cmd would clear out all the filters before recording, it could
take up to 2 minutes to do a recording of "sleep 1".
To find out where the issues was:
~# trace-cmd sqlhist -e -n sched_stack select start.prev_state as state, end.next_comm as comm, TIMESTAMP_DELTA_USECS as delta, start.STACKTRACE as stack from sched_switch as start join sched_switch as end on start.prev_pid = end.next_pid
Which will produce the following commands (and -e will also execute them):
echo 's:sched_stack s64 state; char comm[16]; u64 delta; unsigned long stack[];' >> /sys/kernel/tracing/dynamic_events
echo 'hist:keys=prev_pid:__arg_18057_2=prev_state,__arg_18057_4=common_timestamp.usecs,__arg_18057_7=common_stacktrace' >> /sys/kernel/tracing/events/sched/sched_switch/trigger
echo 'hist:keys=next_pid:__state_18057_1=$__arg_18057_2,__comm_18057_3=next_comm,__delta_18057_5=common_timestamp.usecs-$__arg_18057_4,__stack_18057_6=$__arg_18057_7:onmatch(sched.sched_switch).trace(sched_stack,$__state_18057_1,$__comm_18057_3,$__delta_18057_5,$__stack_18057_6)' >> /sys/kernel/tracing/events/sched/sched_switch/trigger
The above creates a synthetic event that creates a stack trace when a task
schedules out and records it with the time it scheduled back in. Basically
the time a task is off the CPU. It also records the state of the task when
it left the CPU (running, blocked, sleeping, etc). It also saves the comm
of the task as "comm" (needed for the next command).
~# echo 'hist:keys=state,stack.stacktrace:vals=delta:sort=state,delta if comm == "trace-cmd" && state & 3' > /sys/kernel/tracing/events/synthetic/sched_stack/trigger
The above creates a histogram with buckets per state, per stack, and the
value of the total time it was off the CPU for that stack trace. It filters
on tasks with "comm == trace-cmd" and only the sleeping and blocked states
(1 - sleeping, 2 - blocked).
~# trace-cmd record -p function sleep 1
~# cat /sys/kernel/tracing/events/synthetic/sched_stack/hist | tail -18
{ state: 2, stack.stacktrace __schedule+0x1545/0x3700
schedule+0xe2/0x390
schedule_timeout+0x175/0x200
wait_for_completion_state+0x294/0x440
__wait_rcu_gp+0x247/0x4f0
synchronize_rcu_tasks_generic+0x151/0x230
apply_subsystem_event_filter+0xa2b/0x1300
subsystem_filter_write+0x67/0xc0
vfs_write+0x1e2/0xeb0
ksys_write+0xff/0x1d0
do_syscall_64+0x7b/0x420
entry_SYSCALL_64_after_hwframe+0x76/0x7e
} hitcount: 237 delta: 99756288 <<--------------- Delta is 99 seconds!
Totals:
Hits: 525
Entries: 21
Dropped: 0
This shows that this particular trace waited for 99 seconds on
synchronize_rcu_tasks() in apply_subsystem_event_filter().
In fact, there's a lot of places in the filter code that spends a lot of
time waiting for synchronize_rcu_tasks_trace() in order to free the
filters.
Add helper functions that will use call_rcu*() variants to asynchronously
free the filters. This brings the timings back to normal:
# time trace-cmd record -p function sleep 1
[..]
real 0m14.681s
user 0m0.335s
sys 0m28.616s
And the histogram also shows this:
~# cat /sys/kernel/tracing/events/synthetic/sched_stack/hist | tail -21
{ state: 2, stack.stacktrace __schedule+0x1545/0x3700
schedule+0xe2/0x390
schedule_timeout+0x175/0x200
wait_for_completion_state+0x294/0x440
__wait_rcu_gp+0x247/0x4f0
synchronize_rcu_normal+0x3db/0x5c0
tracing_reset_online_cpus+0x8f/0x1e0
tracing_open+0x335/0x440
do_dentry_open+0x4c6/0x17a0
vfs_open+0x82/0x360
path_openat+0x1a36/0x2990
do_filp_open+0x1c5/0x420
do_sys_openat2+0xed/0x180
__x64_sys_openat+0x108/0x1d0
do_syscall_64+0x7b/0x420
} hitcount: 2 delta: 77044
Totals:
Hits: 55
Entries: 28
Dropped: 0
Where the total waiting time of synchronize_rcu_tasks_trace() is 77
milliseconds.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Andreas Ziegler <ziegler.andreas@siemens.com>
Cc: Felix MOESSBAUER <felix.moessbauer@siemens.com>
Link: https://lore.kernel.org/20250606201936.1e3d09a9@batman.local.home
Reported-by: "Flot, Julien" <julien.flot@siemens.com>
Tested-by: Julien Flot <julien.flot@siemens.com>
Fixes: a363d27cdb ("tracing: Allow system call tracepoints to handle page faults")
Closes: https://lore.kernel.org/all/240017f656631c7dd4017aa93d91f41f653788ea.camel@siemens.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
riscv patches for 6.16-rc1, part 2
* Performance improvements
- Add support for vdso getrandom
- Implement raid6 calculations using vectors
- Introduce svinval tlb invalidation
* Cleanup
- A bunch of deduplication of the macros we use for manipulating instructions
* Misc
- Introduce a kunit test for kprobes
- Add support for mseal as riscv fits the requirements (thanks to Lorenzo for making sure of that :))
[Palmer: There was a rebase between part 1 and part 2, so I've had to do
some more git surgery here... at least two rounds of surgery...]
* alex-pr-2: (866 commits)
RISC-V: vDSO: Wire up getrandom() vDSO implementation
riscv: enable mseal sysmap for RV64
raid6: Add RISC-V SIMD syndrome and recovery calculations
riscv: mm: Add support for Svinval extension
riscv: Add kprobes KUnit test
riscv: kprobes: Remove duplication of RV_EXTRACT_ITYPE_IMM
riscv: kprobes: Remove duplication of RV_EXTRACT_UTYPE_IMM
riscv: kprobes: Remove duplication of RV_EXTRACT_RD_REG
riscv: kprobes: Remove duplication of RVC_EXTRACT_BTYPE_IMM
riscv: kprobes: Remove duplication of RVC_EXTRACT_C2_RS1_REG
riscv: kproves: Remove duplication of RVC_EXTRACT_JTYPE_IMM
riscv: kprobes: Remove duplication of RV_EXTRACT_BTYPE_IMM
riscv: kprobes: Remove duplication of RV_EXTRACT_RS1_REG
riscv: kprobes: Remove duplication of RV_EXTRACT_JTYPE_IMM
riscv: kprobes: Move branch_funct3 to insn.h
riscv: kprobes: Move branch_rs2_idx to insn.h
Linux 6.15-rc6
Input: xpad - fix xpad_device sorting
Input: xpad - add support for several more controllers
Input: xpad - fix Share button on Xbox One controllers
...
The following ftrace patch for riscv uses a data store to update ftrace
function. Therefore, a romote fence is required to order it against
function_trace_op updates. The mechanism is similar to the fence between
function_trace_op and update_ftrace_func in the generic ftrace, so we
leverage the same ftrace_sync_ipi function.
[ alex: Fix build warning when !CONFIG_DYNAMIC_FTRACE ]
Signed-off-by: Andy Chiu <andybnac@gmail.com>
Link: https://lore.kernel.org/r/20250407180838.42877-4-andybnac@gmail.com
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
If ftrace is disabled, it is meaningless to allocate a module map.
Add a check in allocate_ftrace_mod_map() to not allocate if ftrace is
disabled.
Link: https://lore.kernel.org/20250529111955.2349189-3-yebin@huaweicloud.com
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The following issue happens with a buggy module:
BUG: unable to handle page fault for address: ffffffffc05d0218
PGD 1bd66f067 P4D 1bd66f067 PUD 1bd671067 PMD 101808067 PTE 0
Oops: Oops: 0000 [#1] SMP KASAN PTI
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
RIP: 0010:sized_strscpy+0x81/0x2f0
RSP: 0018:ffff88812d76fa08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffffc0601010 RCX: dffffc0000000000
RDX: 0000000000000038 RSI: dffffc0000000000 RDI: ffff88812608da2d
RBP: 8080808080808080 R08: ffff88812608da2d R09: ffff88812608da68
R10: ffff88812608d82d R11: ffff88812608d810 R12: 0000000000000038
R13: ffff88812608da2d R14: ffffffffc05d0218 R15: fefefefefefefeff
FS: 00007fef552de740(0000) GS:ffff8884251c7000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffc05d0218 CR3: 00000001146f0000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ftrace_mod_get_kallsym+0x1ac/0x590
update_iter_mod+0x239/0x5b0
s_next+0x5b/0xa0
seq_read_iter+0x8c9/0x1070
seq_read+0x249/0x3b0
proc_reg_read+0x1b0/0x280
vfs_read+0x17f/0x920
ksys_read+0xf3/0x1c0
do_syscall_64+0x5f/0x2e0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The above issue may happen as follows:
(1) Add kprobe tracepoint;
(2) insmod test.ko;
(3) Module triggers ftrace disabled;
(4) rmmod test.ko;
(5) cat /proc/kallsyms; --> Will trigger UAF as test.ko already removed;
ftrace_mod_get_kallsym()
...
strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
...
The problem is when a module triggers an issue with ftrace and
sets ftrace_disable. The ftrace_disable is set when an anomaly is
discovered and to prevent any more damage, ftrace stops all text
modification. The issue that happened was that the ftrace_disable stops
more than just the text modification.
When a module is loaded, its init functions can also be traced. Because
kallsyms deletes the init functions after a module has loaded, ftrace
saves them when the module is loaded and function tracing is enabled. This
allows the output of the function trace to show the init function names
instead of just their raw memory addresses.
When a module is removed, ftrace_release_mod() is called, and if
ftrace_disable is set, it just returns without doing anything more. The
problem here is that it leaves the mod_list still around and if kallsyms
is called, it will call into this code and access the module memory that
has already been freed as it will return:
strscpy(module_name, mod_map->mod->name, MODULE_NAME_LEN);
Where the "mod" no longer exists and triggers a UAF bug.
Link: https://lore.kernel.org/all/20250523135452.626d8dcd@gandalf.local.home/
Cc: stable@vger.kernel.org
Fixes: aba4b5c22c ("ftrace: Save module init functions kallsyms symbols for tracing")
Link: https://lore.kernel.org/20250529111955.2349189-2-yebin@huaweicloud.com
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Allow the persistent ring buffer to be memory mapped
In the last merge window there was issues with the implementation of
mapping the persistent ring buffer because it was assumed that the
persistent memory was just physical memory without being part of the
kernel virtual address space. But this was incorrect and the persistent
ring buffer can be mapped the same way as the allocated ring buffer is
mapped.
The meta data for the persistent ring buffer is different than the normal
ring buffer and the organization of mapping it to user space is a little
different. Make the updates needed to the meta data to allow the
persistent ring buffer to be mapped to user space.
- Fix cpus_read_lock() with buffer->mutex and cpu_buffer->mapping_lock
Mapping the ring buffer to user space uses the cpu_buffer->mapping_lock.
The buffer->mutex can be taken when the mapping_lock is held, giving the
locking order of: cpu_buffer->mapping_lock -->> buffer->mutex. But there
also exists the ordering:
buffer->mutex -->> cpus_read_lock()
mm->mmap_lock -->> cpu_buffer->mapping_lock
cpus_read_lock() -->> mm->mmap_lock
causing a circular chain of:
cpu_buffer->mapping_lock -> buffer->mutex -->> cpus_read_lock() -->>
mm->mmap_lock -->> cpu_buffer->mapping_lock
By moving the cpus_read_lock() outside the buffer->mutex where:
cpus_read_lock() -->> buffer->mutex, breaks the deadlock chain.
- Do not trigger WARN_ON() for commit overrun
When the ring buffer is user space mapped and there's a "commit overrun"
(where an interrupt preempted an event, and then added so many events it
filled the buffer having to drop events when it hit the preempted event)
a WARN_ON() was triggered if this was read via a memory mapped buffer.
This is due to "missed events" being non zero when the reader page ended
up with the commit page. The idea was, if the writer is on the reader page,
there's only one page that has been written to and there should be no
missed events. But if a commit overrun is done where the writer is off the
commit page and looped around to the commit page causing missed events, it
is possible that the reader page is the commit page with missed events.
Instead of triggering a WARN_ON() when the reader page is the commit page
with missed events, trigger it when the reader page is the tail_page with
missed events. That's because the writer is always on the tail_page if
an event was interrupted (which holds the commit event) and continues off
the commit page.
- Reset the persistent buffer if it is fully consumed
On boot up, if the user fully consumes the last boot buffer of the
persistent buffer, if it reboots without enabling it, there will still be
events in the buffer which can cause confusion. Instead, reset the buffer
when it is fully consumed, so that the data is not read again.
- Clean up some goto out jumps
There's a few cases that the code jumps to the "out:" label that simply
returns a value. There used to be more work done at those labels but now
that they simply return a value use a return instead of jumping to a
label.
- Use guard() to simplify some of the code
Add guard() around some locking instead of jumping to a label to do the
unlocking.
- Use free() to simplify some of the code
Use free(kfree) on variables that will get freed on error and use
return_ptr() to return the variable when its not freed. There's one
instance where free(kfree) simplifies the code on a temp variable that was
allocated just for the function use.
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Merge tag 'trace-ringbuffer-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer updates from Steven Rostedt:
- Allow the persistent ring buffer to be memory mapped
In the last merge window there was issues with the implementation of
mapping the persistent ring buffer because it was assumed that the
persistent memory was just physical memory without being part of the
kernel virtual address space. But this was incorrect and the
persistent ring buffer can be mapped the same way as the allocated
ring buffer is mapped.
The metadata for the persistent ring buffer is different than the
normal ring buffer and the organization of mapping it to user space
is a little different. Make the updates needed to the meta data to
allow the persistent ring buffer to be mapped to user space.
- Fix cpus_read_lock() with buffer->mutex and cpu_buffer->mapping_lock
Mapping the ring buffer to user space uses the
cpu_buffer->mapping_lock. The buffer->mutex can be taken when the
mapping_lock is held, giving the locking order of:
cpu_buffer->mapping_lock -->> buffer->mutex. But there also exists
the ordering:
buffer->mutex -->> cpus_read_lock()
mm->mmap_lock -->> cpu_buffer->mapping_lock
cpus_read_lock() -->> mm->mmap_lock
causing a circular chain of:
cpu_buffer->mapping_lock -> buffer->mutex -->> cpus_read_lock() -->>
mm->mmap_lock -->> cpu_buffer->mapping_lock
By moving the cpus_read_lock() outside the buffer->mutex where:
cpus_read_lock() -->> buffer->mutex, breaks the deadlock chain.
- Do not trigger WARN_ON() for commit overrun
When the ring buffer is user space mapped and there's a "commit
overrun" (where an interrupt preempted an event, and then added so
many events it filled the buffer having to drop events when it hit
the preempted event) a WARN_ON() was triggered if this was read via a
memory mapped buffer.
This is due to "missed events" being non zero when the reader page
ended up with the commit page. The idea was, if the writer is on the
reader page, there's only one page that has been written to and there
should be no missed events.
But if a commit overrun is done where the writer is off the commit
page and looped around to the commit page causing missed events, it
is possible that the reader page is the commit page with missed
events.
Instead of triggering a WARN_ON() when the reader page is the commit
page with missed events, trigger it when the reader page is the
tail_page with missed events. That's because the writer is always on
the tail_page if an event was interrupted (which holds the commit
event) and continues off the commit page.
- Reset the persistent buffer if it is fully consumed
On boot up, if the user fully consumes the last boot buffer of the
persistent buffer, if it reboots without enabling it, there will
still be events in the buffer which can cause confusion. Instead,
reset the buffer when it is fully consumed, so that the data is not
read again.
- Clean up some goto out jumps
There's a few cases that the code jumps to the "out:" label that
simply returns a value. There used to be more work done at those
labels but now that they simply return a value use a return instead
of jumping to a label.
- Use guard() to simplify some of the code
Add guard() around some locking instead of jumping to a label to do
the unlocking.
- Use free() to simplify some of the code
Use free(kfree) on variables that will get freed on error and use
return_ptr() to return the variable when its not freed. There's one
instance where free(kfree) simplifies the code on a temp variable
that was allocated just for the function use.
* tag 'trace-ringbuffer-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Simplify functions with __free(kfree) to free allocations
ring-buffer: Make ring_buffer_{un}map() simpler with guard(mutex)
ring-buffer: Simplify ring_buffer_read_page() with guard()
ring-buffer: Simplify reset_disabled_cpu_buffer() with use of guard()
ring-buffer: Remove jump to out label in ring_buffer_swap_cpu()
ring-buffer: Removed unnecessary if() goto out where out is the next line
tracing: Reset last-boot buffers when reading out all cpu buffers
ring-buffer: Allow reserve_mem persistent ring buffers to be mmapped
ring-buffer: Do not trigger WARN_ON() due to a commit_overrun
ring-buffer: Move cpus_read_lock() outside of buffer->mutex
Calling conventions of ->d_automount() made saner (flagday change)
vfs_submount() is gone - its sole remaining user (trace_automount) had
been switched to saner primitives.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull automount updates from Al Viro:
"Automount wart removal
A bunch of odd boilerplate gone from instances - the reason for
those was the need to protect the yet-to-be-attched mount from
mark_mounts_for_expiry() deciding to take it out.
But that's easy to detect and take care of in mark_mounts_for_expiry()
itself; no need to have every instance simulate mount being busy by
grabbing an extra reference to it, with finish_automount() undoing
that once it attaches that mount.
Should've done it that way from the very beginning... This is a
flagday change, thankfully there are very few instances.
vfs_submount() is gone - its sole remaining user (trace_automount)
had been switched to saner primitives"
* tag 'pull-automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
kill vfs_submount()
saner calling conventions for ->d_automount()
- Have module addresses get updated in the persistent ring buffer
The addresses of the modules from the previous boot are saved in the
persistent ring buffer. If the same modules are loaded and an address is
in the old buffer points to an address that was both saved in the
persistent ring buffer and is loaded in memory, shift the address to point
to the address that is loaded in memory in the trace event.
- Print function names for irqs off and preempt off callsites
When ignoring the print fmt of a trace event and just printing the fields
directly, have the fields for preempt off and irqs off events still show
the function name (via kallsyms) instead of just showing the raw address.
- Clean ups of the histogram code
The histogram functions saved over 800 bytes on the stack to process
events as they come in. Instead, create per-cpu buffers that can hold this
information and have a separate location for each context level (thread,
softirq, IRQ and NMI).
Also add some more comments to the code.
- Add "common_comm" field for histograms
Add "common_comm" that uses the current->comm as a field in an event
histogram and acts like any of the other fields of the event.
- Show "subops" in the enabled_functions file
When the function graph infrastructure is used, a subsystem has a "subops"
that it attaches its callback function to. Instead of the
enabled_functions just showing a function calling the function that calls
the subops functions, also show the subops functions that will get called
for that function too.
- Add "copy_trace_marker" option to instances
There are cases where an instance is created for tooling to write into,
but the old tooling has the top level instance hardcoded into the
application. New tools want to consume the data from an instance and not
the top level buffer. By adding a copy_trace_marker option, whenever the
top instance trace_marker is written into, a copy of it is also written
into the instance with this option set. This allows new tools to read what
old tools are writing into the top buffer.
If this option is cleared by the top instance, then what is written into
the trace_marker is not written into the top instance. This is a way to
redirect the trace_marker writes into another instance.
- Have tracepoints created by DECLARE_TRACE() use trace_<name>_tp()
If a tracepoint is created by DECLARE_TRACE() instead of TRACE_EVENT(),
then it will not be exposed via tracefs. Currently there's no way to
differentiate in the kernel the tracepoint functions between those that
are exposed via tracefs or not. A calling convention has been made
manually to append a "_tp" prefix for events created by DECLARE_TRACE().
Instead of doing this manually, force it so that all DECLARE_TRACE()
events have this notation.
- Use __string() for task->comm in some sched events
Instead of hardcoding the comm to be TASK_COMM_LEN in some of the
scheduler events use __string() which makes it dynamic. Note, if these
events are parsed by user space it they may break, and the event may have
to be converted back to the hardcoded size.
- Have function graph "depth" be unsigned to the user
Internally to the kernel, the "depth" field of the function graph event is
signed due to -1 being used for end of boundary. What actually gets
recorded in the event itself is zero or positive. Reflect this to user
space by showing "depth" as unsigned int and be consistent across all
events.
- Allow an arbitrary long CPU string to osnoise_cpus_write()
The filtering of which CPUs to write to can exceed 256 bytes. If a machine
has 256 CPUs, and the filter is to filter every other CPU, the write would
take a string larger than 256 bytes. Instead of using a fixed size buffer
on the stack that is 256 bytes, allocate it to handle what is passed in.
- Stop having ftrace check the per-cpu data "disabled" flag
The "disabled" flag in the data structure passed to most ftrace functions
is checked to know if tracing has been disabled or not. This flag was
added back in 2008 before the ring buffer had its own way to disable
tracing. The "disable" flag is now not always set when needed, and the
ring buffer flag should be used in all locations where the disabled is
needed. Since the "disable" flag is redundant and incorrect, stop using it.
Fix up some locations that use the "disable" flag to use the ring buffer
info.
- Use a new tracer_tracing_disable/enable() instead of data->disable flag
There's a few cases that set the data->disable flag to stop tracing, but
this flag is not consistently used. It is also an on/off switch where if a
function set it and calls another function that sets it, the called
function may incorrectly enable it.
Use a new trace_tracing_disable() and tracer_tracing_enable() that uses a
counter and can be nested. These use the ring buffer flags which are
always checked making the disabling more consistent.
- Save the trace clock in the persistent ring buffer
Save what clock was used for tracing in the persistent ring buffer and set
it back to that clock after a reboot.
- Remove unused reference to a per CPU data pointer in mmiotrace functions
- Remove unused buffer_page field from trace_array_cpu structure
- Remove more strncpy() instances
- Other minor clean ups and fixes
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Merge tag 'trace-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Have module addresses get updated in the persistent ring buffer
The addresses of the modules from the previous boot are saved in the
persistent ring buffer. If the same modules are loaded and an address
is in the old buffer points to an address that was both saved in the
persistent ring buffer and is loaded in memory, shift the address to
point to the address that is loaded in memory in the trace event.
- Print function names for irqs off and preempt off callsites
When ignoring the print fmt of a trace event and just printing the
fields directly, have the fields for preempt off and irqs off events
still show the function name (via kallsyms) instead of just showing
the raw address.
- Clean ups of the histogram code
The histogram functions saved over 800 bytes on the stack to process
events as they come in. Instead, create per-cpu buffers that can hold
this information and have a separate location for each context level
(thread, softirq, IRQ and NMI).
Also add some more comments to the code.
- Add "common_comm" field for histograms
Add "common_comm" that uses the current->comm as a field in an event
histogram and acts like any of the other fields of the event.
- Show "subops" in the enabled_functions file
When the function graph infrastructure is used, a subsystem has a
"subops" that it attaches its callback function to. Instead of the
enabled_functions just showing a function calling the function that
calls the subops functions, also show the subops functions that will
get called for that function too.
- Add "copy_trace_marker" option to instances
There are cases where an instance is created for tooling to write
into, but the old tooling has the top level instance hardcoded into
the application. New tools want to consume the data from an instance
and not the top level buffer. By adding a copy_trace_marker option,
whenever the top instance trace_marker is written into, a copy of it
is also written into the instance with this option set. This allows
new tools to read what old tools are writing into the top buffer.
If this option is cleared by the top instance, then what is written
into the trace_marker is not written into the top instance. This is a
way to redirect the trace_marker writes into another instance.
- Have tracepoints created by DECLARE_TRACE() use trace_<name>_tp()
If a tracepoint is created by DECLARE_TRACE() instead of
TRACE_EVENT(), then it will not be exposed via tracefs. Currently
there's no way to differentiate in the kernel the tracepoint
functions between those that are exposed via tracefs or not. A
calling convention has been made manually to append a "_tp" prefix
for events created by DECLARE_TRACE(). Instead of doing this
manually, force it so that all DECLARE_TRACE() events have this
notation.
- Use __string() for task->comm in some sched events
Instead of hardcoding the comm to be TASK_COMM_LEN in some of the
scheduler events use __string() which makes it dynamic. Note, if
these events are parsed by user space it they may break, and the
event may have to be converted back to the hardcoded size.
- Have function graph "depth" be unsigned to the user
Internally to the kernel, the "depth" field of the function graph
event is signed due to -1 being used for end of boundary. What
actually gets recorded in the event itself is zero or positive.
Reflect this to user space by showing "depth" as unsigned int and be
consistent across all events.
- Allow an arbitrary long CPU string to osnoise_cpus_write()
The filtering of which CPUs to write to can exceed 256 bytes. If a
machine has 256 CPUs, and the filter is to filter every other CPU,
the write would take a string larger than 256 bytes. Instead of using
a fixed size buffer on the stack that is 256 bytes, allocate it to
handle what is passed in.
- Stop having ftrace check the per-cpu data "disabled" flag
The "disabled" flag in the data structure passed to most ftrace
functions is checked to know if tracing has been disabled or not.
This flag was added back in 2008 before the ring buffer had its own
way to disable tracing. The "disable" flag is now not always set when
needed, and the ring buffer flag should be used in all locations
where the disabled is needed. Since the "disable" flag is redundant
and incorrect, stop using it. Fix up some locations that use the
"disable" flag to use the ring buffer info.
- Use a new tracer_tracing_disable/enable() instead of data->disable
flag
There's a few cases that set the data->disable flag to stop tracing,
but this flag is not consistently used. It is also an on/off switch
where if a function set it and calls another function that sets it,
the called function may incorrectly enable it.
Use a new trace_tracing_disable() and tracer_tracing_enable() that
uses a counter and can be nested. These use the ring buffer flags
which are always checked making the disabling more consistent.
- Save the trace clock in the persistent ring buffer
Save what clock was used for tracing in the persistent ring buffer
and set it back to that clock after a reboot.
- Remove unused reference to a per CPU data pointer in mmiotrace
functions
- Remove unused buffer_page field from trace_array_cpu structure
- Remove more strncpy() instances
- Other minor clean ups and fixes
* tag 'trace-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (36 commits)
tracing: Fix compilation warning on arm32
tracing: Record trace_clock and recover when reboot
tracing/sched: Use __string() instead of fixed lengths for task->comm
tracepoint: Have tracepoints created with DECLARE_TRACE() have _tp suffix
tracing: Cleanup upper_empty() in pid_list
tracing: Allow the top level trace_marker to write into another instances
tracing: Add a helper function to handle the dereference arg in verifier
tracing: Remove unnecessary "goto out" that simply returns ret is trigger code
tracing: Fix error handling in event_trigger_parse()
tracing: Rename event_trigger_alloc() to trigger_data_alloc()
tracing: Replace deprecated strncpy() with strscpy() for stack_trace_filter_buf
tracing: Remove unused buffer_page field from trace_array_cpu structure
tracing: Use atomic_inc_return() for updating "disabled" counter in irqsoff tracer
tracing: Convert the per CPU "disabled" counter to local from atomic
tracing: branch: Use trace_tracing_is_on_cpu() instead of "disabled" field
ring-buffer: Add ring_buffer_record_is_on_cpu()
tracing: Do not use per CPU array_buffer.data->disabled for cpumask
ftrace: Do not disabled function graph based on "disabled" field
tracing: kdb: Use tracer_tracing_on/off() instead of setting per CPU disabled
tracing: Use tracer_tracing_disable() instead of "disabled" field for ftrace_dump_one()
...
The function rb_allocate_pages() allocates cpu_buffer and on error needs
to free it. It has a single return. Use __free(kfree) and return directly
on errors and have the return use return_ptr(cpu_buffer).
The function alloc_buffer() allocates buffer and on error needs to free
it. It has a single return. Use __free(kfree) and return directly on
errors and have the return use return_ptr(buffer).
The function __rb_map_vma() allocates a temporary array "pages". Have it
use __free() and not worry about freeing it when returning.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250527143144.6edc4625@gandalf.local.home
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Convert the taking of the buffer->mutex and the cpu_buffer->mapping_lock
over to guard(mutex) and simplify the ring_buffer_map() and
ring_buffer_unmap() functions.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20250527122009.267efb72@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function ring_buffer_read_page() had two gotos. One was simply
returning "ret" and the other was unlocking the reader_lock.
There's no reason to use goto to simply return the "ret" variable. Instead
just return the value.
The jump to the unlocking of the reader_lock can be replaced by
guard(raw_spinlock_irqsave)(&cpu_buffer->reader_lock).
With these two changes the "ret" variable is no longer used and can be
removed. The return value on non-error is what was read and is stored in
the "read" variable.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250527145216.0187cf36@gandalf.local.home
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Use guard(raw_spinlock_irqsave)() in reset_disabled_cpu_buffer() to
simplify the locking.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250527144623.77a9cc47@gandalf.local.home
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function ring_buffer_swap_cpu() has a bunch of jumps to the label out
that simply returns "ret". There's no reason to jump to a label that
simply returns a value. Just return directly from there.
This goes back to almost the beginning when commit 8aabee573d
("ring-buffer: remove unneeded get_online_cpus") was introduced. That
commit removed a put_online_cpus() from that label, but never updated all
the jumps to it that now no longer needed to do anything but return a
value.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250527145753.6b45d840@gandalf.local.home
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
In the function ring_buffer_discard_commit() there's an if statement that
jumps to the next line:
if (rb_try_to_discard(cpu_buffer, event))
goto out;
out:
This was caused by the change that modified the way timestamps were taken
in interrupt context, and removed the code between the if statement and
the goto, but failed to update the conditional logic.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250527155116.227f35be@gandalf.local.home
Fixes: a389d86f7f ("ring-buffer: Have nested events still record running time stamp")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reset the last-boot ring buffers when read() reads out all cpu
buffers through trace_pipe/trace_pipe_raw. This prevents ftrace to
unwind ring buffer read pointer next boot.
Note that this resets only when all per-cpu buffers are empty, and
read via read(2) syscall. For example, if you read only one of the
per-cpu trace_pipe, it does not reset it. Also, reading buffer by
splice(2) syscall does not reset because some data in the reader
(the last) page.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/174792929202.496143.8184644221859580999.stgit@mhiramat.tok.corp.google.com
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When the persistent ring buffer is created from the memory returned by
reserve_mem there is nothing prohibiting it to be memory mapped to user
space. The memory is the same as the pages allocated by alloc_page().
The way the memory is managed by the ring buffer code is slightly
different though and needs to be addressed.
The persistent memory uses the page->id for its own purpose where as the
user mmap buffer currently uses that for the subbuf array mapped to user
space. If the buffer is a persistent buffer, use the page index into that
buffer as the identifier instead of the page->id.
That is, the page->id for a persistent buffer, represents the order of the
buffer is in the link list. ->id == 0 means it is the reader page.
When a reader page is swapped, the new reader page's ->id gets zero, and
the old reader page gets the ->id of the page that it swapped with.
The user space mapping has the ->id is the index of where it was mapped in
user space and does not change while it is mapped.
Since the persistent buffer is fixed in its location, the index of where
a page is in the memory range can be used as the "id" to put in the meta
page array, and it can be mapped in the same order to user space as it is
in the persistent memory.
A new rb_page_id() helper function is used to get and set the id depending
on if the page is a normal memory allocated buffer or a physical memory
mapped buffer.
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/20250401203332.246646011@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When reading a memory mapped buffer the reader page is just swapped out
with the last page written in the write buffer. If the reader page is the
same as the commit buffer (the buffer that is currently being written to)
it was assumed that it should never have missed events. If it does, it
triggers a WARN_ON_ONCE().
But there just happens to be one scenario where this can legitimately
happen. That is on a commit_overrun. A commit overrun is when an interrupt
preempts an event being written to the buffer and then the interrupt adds
so many new events that it fills and wraps the buffer back to the commit.
Any new events would then be dropped and be reported as "missed_events".
In this case, the next page to read is the commit buffer and after the
swap of the reader page, the reader page will be the commit buffer, but
this time there will be missed events and this triggers the following
warning:
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1127 at kernel/trace/ring_buffer.c:7357 ring_buffer_map_get_reader+0x49a/0x780
Modules linked in: kvm_intel kvm irqbypass
CPU: 2 UID: 0 PID: 1127 Comm: trace-cmd Not tainted 6.15.0-rc7-test-00004-g478bc2824b45-dirty #564 PREEMPT
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:ring_buffer_map_get_reader+0x49a/0x780
Code: 00 00 00 48 89 fe 48 c1 ee 03 80 3c 2e 00 0f 85 ec 01 00 00 4d 3b a6 a8 00 00 00 0f 85 8a fd ff ff 48 85 c0 0f 84 55 fe ff ff <0f> 0b e9 4e fe ff ff be 08 00 00 00 4c 89 54 24 58 48 89 54 24 50
RSP: 0018:ffff888121787dc0 EFLAGS: 00010002
RAX: 00000000000006a2 RBX: ffff888100062800 RCX: ffffffff8190cb49
RDX: ffff888126934c00 RSI: 1ffff11020200a15 RDI: ffff8881010050a8
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffed1024d26982
R10: ffff888126934c17 R11: ffff8881010050a8 R12: ffff888126934c00
R13: ffff8881010050b8 R14: ffff888101005000 R15: ffff888126930008
FS: 00007f95c8cd7540(0000) GS:ffff8882b576e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f95c8de4dc0 CR3: 0000000128452002 CR4: 0000000000172ef0
Call Trace:
<TASK>
? __pfx_ring_buffer_map_get_reader+0x10/0x10
tracing_buffers_ioctl+0x283/0x370
__x64_sys_ioctl+0x134/0x190
do_syscall_64+0x79/0x1c0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f95c8de48db
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007ffe037ba110 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffe037bb2b0 RCX: 00007f95c8de48db
RDX: 0000000000000000 RSI: 0000000000005220 RDI: 0000000000000006
RBP: 00007ffe037ba180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe037bb6f8 R14: 00007f95c9065000 R15: 00005575c7492c90
</TASK>
irq event stamp: 5080
hardirqs last enabled at (5079): [<ffffffff83e0adb0>] _raw_spin_unlock_irqrestore+0x50/0x70
hardirqs last disabled at (5080): [<ffffffff83e0aa83>] _raw_spin_lock_irqsave+0x63/0x70
softirqs last enabled at (4182): [<ffffffff81516122>] handle_softirqs+0x552/0x710
softirqs last disabled at (4159): [<ffffffff815163f7>] __irq_exit_rcu+0x107/0x210
---[ end trace 0000000000000000 ]---
The above was triggered by running on a kernel with both lockdep and KASAN
as well as kmemleak enabled and executing the following command:
# perf record -o perf-test.dat -a -- trace-cmd record --nosplice -e all -p function hackbench 50
With perf interjecting a lot of interrupts and trace-cmd enabling all
events as well as function tracing, with lockdep, KASAN and kmemleak
enabled, it could cause an interrupt preempting an event being written to
add enough events to wrap the buffer. trace-cmd was modified to have
--nosplice use mmap instead of reading the buffer.
The way to differentiate this case from the normal case of there only
being one page written to where the swap of the reader page received that
one page (which is the commit page), check if the tail page is on the
reader page. The difference between the commit page and the tail page is
that the tail page is where new writes go to, and the commit page holds
the first write that hasn't been committed yet. In the case of an
interrupt preempting the write of an event and filling the buffer, it
would move the tail page but not the commit page.
Have the warning only trigger if the tail page is also on the reader page,
and also print out the number of events dropped by a commit overrun as
that can not yet be safely added to the page so that the reader can see
there were events dropped.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20250528121555.2066527e@gandalf.local.home
Fixes: fe832be05a ("ring-buffer: Have mmapped ring buffer keep track of missed events")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Merge tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Fix and improve BTF deduplication of identical BTF types (Alan
Maguire and Andrii Nakryiko)
- Support up to 12 arguments in BPF trampoline on arm64 (Xu Kuohai and
Alexis Lothoré)
- Support load-acquire and store-release instructions in BPF JIT on
riscv64 (Andrea Parri)
- Fix uninitialized values in BPF_{CORE,PROBE}_READ macros (Anton
Protopopov)
- Streamline allowed helpers across program types (Feng Yang)
- Support atomic update for hashtab of BPF maps (Hou Tao)
- Implement json output for BPF helpers (Ihor Solodrai)
- Several s390 JIT fixes (Ilya Leoshkevich)
- Various sockmap fixes (Jiayuan Chen)
- Support mmap of vmlinux BTF data (Lorenz Bauer)
- Support BPF rbtree traversal and list peeking (Martin KaFai Lau)
- Tests for sockmap/sockhash redirection (Michal Luczaj)
- Introduce kfuncs for memory reads into dynptrs (Mykyta Yatsenko)
- Add support for dma-buf iterators in BPF (T.J. Mercier)
- The verifier support for __bpf_trap() (Yonghong Song)
* tag 'bpf-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (135 commits)
bpf, arm64: Remove unused-but-set function and variable.
selftests/bpf: Add tests with stack ptr register in conditional jmp
bpf: Do not include stack ptr register in precision backtracking bookkeeping
selftests/bpf: enable many-args tests for arm64
bpf, arm64: Support up to 12 function arguments
bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem()
bpf: Avoid __bpf_prog_ret0_warn when jit fails
bpftool: Add support for custom BTF path in prog load/loadall
selftests/bpf: Add unit tests with __bpf_trap() kfunc
bpf: Warn with __bpf_trap() kfunc maybe due to uninitialized variable
bpf: Remove special_kfunc_set from verifier
selftests/bpf: Add test for open coded dmabuf_iter
selftests/bpf: Add test for dmabuf_iter
bpf: Add open coded dmabuf iterator
bpf: Add dmabuf iterator
dma-buf: Rename debugfs symbols
bpf: Fix error return value in bpf_copy_from_user_dynptr
libbpf: Use mmap to parse vmlinux BTF from sysfs
selftests: bpf: Add a test for mmapable vmlinux BTF
btf: Allow mmap of vmlinux btf
...
On arm32, size_t is defined to be unsigned int, while PAGE_SIZE is
unsigned long. This hence triggers a compilation warning as min()
asserts the type of two operands to be equal. Casting PAGE_SIZE to size_t
solves this issue and works on other target architectures as well.
Compilation warning details:
kernel/trace/trace.c: In function 'tracing_splice_read_pipe':
./include/linux/minmax.h:20:28: warning: comparison of distinct pointer types lacks a cast
(!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
^
./include/linux/minmax.h:26:4: note: in expansion of macro '__typecheck'
(__typecheck(x, y) && __no_side_effects(x, y))
^~~~~~~~~~~
...
kernel/trace/trace.c:6771:8: note: in expansion of macro 'min'
min((size_t)trace_seq_used(&iter->seq),
^~~
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250526013731.1198030-1-pantaixi@huaweicloud.com
Fixes: f5178c41bb ("tracing: Fix oob write in trace_seq_to_buffer()")
Reviewed-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Pan Taixi <pantaixi@huaweicloud.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
* Move kern_table members out of kernel/sysctl.c
Moved a subset (tracing, panic, signal, stack_tracer and sparc) out of the
kern_table array. The goal is for kern_table to only have sysctl elements. All
this increases modularity by placing the ctl_tables closer to where they are
used while reducing the chances of merge conflicts in kernel/sysctl.c.
* Fixed sysctl unit test panic by relocating it to selftests
* Testing
These have been in linux-next from rc2, so they have had more than a month
worth of testing.
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Merge tag 'sysctl-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl
Pull sysctl updates from Joel Granados:
- Move kern_table members out of kernel/sysctl.c
Moved a subset (tracing, panic, signal, stack_tracer and sparc) out
of the kern_table array. The goal is for kern_table to only have
sysctl elements. All this increases modularity by placing the
ctl_tables closer to where they are used while reducing the chances
of merge conflicts in kernel/sysctl.c.
- Fixed sysctl unit test panic by relocating it to selftests
* tag 'sysctl-6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
sysctl: Close test ctl_headers with a for loop
sysctl: call sysctl tests with a for loop
sysctl: Add 0012 to test the u8 range check
sysctl: move u8 register test to lib/test_sysctl.c
sparc: mv sparc sysctls into their own file under arch/sparc/kernel
stack_tracer: move sysctl registration to kernel/trace/trace_stack.c
tracing: Move trace sysctls into trace.c
signal: Move signal ctl tables into signal.c
panic: Move panic ctl tables into panic.c
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Merge tag 'for-6.16/block-20250523' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- ublk updates:
- Add support for updating the size of a ublk instance
- Zero-copy improvements
- Auto-registering of buffers for zero-copy
- Series simplifying and improving GET_DATA and request lookup
- Series adding quiesce support
- Lots of selftests additions
- Various cleanups
- NVMe updates via Christoph:
- add per-node DMA pools and use them for PRP/SGL allocations
(Caleb Sander Mateos, Keith Busch)
- nvme-fcloop refcounting fixes (Daniel Wagner)
- support delayed removal of the multipath node and optionally
support the multipath node for private namespaces (Nilay Shroff)
- support shared CQs in the PCI endpoint target code (Wilfred
Mallawa)
- support admin-queue only authentication (Hannes Reinecke)
- use the crc32c library instead of the crypto API (Eric Biggers)
- misc cleanups (Christoph Hellwig, Marcelo Moreira, Hannes
Reinecke, Leon Romanovsky, Gustavo A. R. Silva)
- MD updates via Yu:
- Fix that normal IO can be starved by sync IO, found by mkfs on
newly created large raid5, with some clean up patches for bdev
inflight counters
- Clean up brd, getting rid of atomic kmaps and bvec poking
- Add loop driver specifically for zoned IO testing
- Eliminate blk-rq-qos calls with a static key, if not enabled
- Improve hctx locking for when a plug has IO for multiple queues
pending
- Remove block layer bouncing support, which in turn means we can
remove the per-node bounce stat as well
- Improve blk-throttle support
- Improve delay support for blk-throttle
- Improve brd discard support
- Unify IO scheduler switching. This should also fix a bunch of lockdep
warnings we've been seeing, after enabling lockdep support for queue
freezing/unfreezeing
- Add support for block write streams via FDP (flexible data placement)
on NVMe
- Add a bunch of block helpers, facilitating the removal of a bunch of
duplicated boilerplate code
- Remove obsolete BLK_MQ pci and virtio Kconfig options
- Add atomic/untorn write support to blktrace
- Various little cleanups and fixes
* tag 'for-6.16/block-20250523' of git://git.kernel.dk/linux: (186 commits)
selftests: ublk: add test for UBLK_F_QUIESCE
ublk: add feature UBLK_F_QUIESCE
selftests: ublk: add test case for UBLK_U_CMD_UPDATE_SIZE
traceevent/block: Add REQ_ATOMIC flag to block trace events
ublk: run auto buf unregisgering in same io_ring_ctx with registering
io_uring: add helper io_uring_cmd_ctx_handle()
ublk: remove io argument from ublk_auto_buf_reg_fallback()
ublk: handle ublk_set_auto_buf_reg() failure correctly in ublk_fetch()
selftests: ublk: add test for covering UBLK_AUTO_BUF_REG_FALLBACK
selftests: ublk: support UBLK_F_AUTO_BUF_REG
ublk: support UBLK_AUTO_BUF_REG_FALLBACK
ublk: register buffer to local io_uring with provided buf index via UBLK_F_AUTO_BUF_REG
ublk: prepare for supporting to register request buffer automatically
ublk: convert to refcount_t
selftests: ublk: make IO & device removal test more stressful
nvme: rename nvme_mpath_shutdown_disk to nvme_mpath_remove_disk
nvme: introduce multipath_always_on module param
nvme-multipath: introduce delayed removal of the multipath head node
nvme-pci: derive and better document max segments limits
nvme-pci: use struct_size for allocation struct nvme_dev
...
On error, copy_from_user returns number of bytes not copied to
destination, but current implementation of copy_user_data_sleepable does
not handle that correctly and returns it as error value, which may
confuse user, expecting meaningful negative error value.
Fixes: a498ee7576 ("bpf: Implement dynptr copy kfuncs")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250523181705.261585-1-mykyta.yatsenko5@gmail.com
Filesystems like XFS can implement atomic write I/O using either
REQ_ATOMIC flag set in the bio or via CoW operation. It will be useful
if we have a flag in trace events to distinguish between the two. This
patch adds char 'U' (Untorn writes) to rwbs field of the trace events
if REQ_ATOMIC flag is set in the bio.
<W/ REQ_ATOMIC>
=================
xfs_io-4238 [009] ..... 4148.126843: block_rq_issue: 259,0 WFSU 16384 () 768 + 32 none,0,0 [xfs_io]
<idle>-0 [009] d.h1. 4148.129864: block_rq_complete: 259,0 WFSU () 768 + 32 none,0,0 [0]
<W/O REQ_ATOMIC>
===============
xfs_io-4237 [010] ..... 4143.325616: block_rq_issue: 259,0 WS 16384 () 768 + 32 none,0,0 [xfs_io]
<idle>-0 [010] d.H1. 4143.329138: block_rq_complete: 259,0 WS () 768 + 32 none,0,0 [0]
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/44317cb2ec4588f6a2c1501a96684e6a1196e8ba.1747921498.git.ritesh.list@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This reverts commit 4a8f635a60.
Althought get_pid_task() internally already calls rcu_read_lock() and
rcu_read_unlock(), the find_vpid() was not.
The documentation for find_vpid() clearly states:
"Must be called with the tasklist_lock or rcu_read_lock() held."
Add proper rcu_read_lock/unlock() to protect the find_vpid().
Fixes: 4a8f635a60 ("bpf: remove unnecessary rcu_read_{lock,unlock}() in multi-uprobe attach logic")
Reported-by: Xuewen Yan <xuewen.yan@unisoc.com>
Signed-off-by: Di Shen <di.shen@unisoc.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250520054943.5002-1-xuewen.yan@unisoc.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
- Fix sample code that uses trace_array_printk()
The sample code for in kernel use of trace_array (that creates an instance
for use within the kernel) and shows how to use trace_array_printk() that
writes into the created instance, used trace_printk_init_buffers(). But
that function is used to initialize normal trace_printk() and produces the
NOTICE banner which is not needed for use of trace_array_printk(). The
function to initialize that is trace_array_init_printk() that takes the
created trace array instance as a parameter.
Update the sample code to reflect the proper usage.
- Fix preemption count output for stacktrace event
The tracing buffer shows the preempt count level when an event executes.
Because writing the event itself disables preemption, this needs to be
accounted for when recording. The stacktrace event did not account for
this so the output of the stacktrace event showed preemption was disabled
while the event that triggered the stacktrace shows preemption is enabled
and this leads to confusion. Account for preemption being disabled for the
stacktrace event.
The same happened for stack traces triggered by function tracer.
- Fix persistent ring buffer when trace_pipe is used
The ring buffer swaps the reader page with the next page to read from the
write buffer when trace_pipe is used. If there's only a page of data in
the ring buffer, this swap will cause the "commit" pointer (last data
written) to be on the reader page. If more data is written to the buffer,
it is added to the reader page until it falls off back into the write
buffer.
If the system reboots and the commit pointer is still on the reader page,
even if new data was written, the persistent buffer validator will miss
finding the commit pointer because it only checks the write buffer and
does not check the reader page. This causes the validator to fail the
validation and clear the buffer, where the new data is lost.
There was a check for this, but it checked the "head pointer", which was
incorrect, because the "head pointer" always stays on the write buffer and
is the next page to swap out for the reader page. Fix the logic to catch
this case and allow the user to still read the data after reboot.
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Merge tag 'trace-v6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix sample code that uses trace_array_printk()
The sample code for in kernel use of trace_array (that creates an
instance for use within the kernel) and shows how to use
trace_array_printk() that writes into the created instance, used
trace_printk_init_buffers(). But that function is used to initialize
normal trace_printk() and produces the NOTICE banner which is not
needed for use of trace_array_printk(). The function to initialize
that is trace_array_init_printk() that takes the created trace array
instance as a parameter.
Update the sample code to reflect the proper usage.
- Fix preemption count output for stacktrace event
The tracing buffer shows the preempt count level when an event
executes. Because writing the event itself disables preemption, this
needs to be accounted for when recording. The stacktrace event did
not account for this so the output of the stacktrace event showed
preemption was disabled while the event that triggered the stacktrace
shows preemption is enabled and this leads to confusion. Account for
preemption being disabled for the stacktrace event.
The same happened for stack traces triggered by function tracer.
- Fix persistent ring buffer when trace_pipe is used
The ring buffer swaps the reader page with the next page to read from
the write buffer when trace_pipe is used. If there's only a page of
data in the ring buffer, this swap will cause the "commit" pointer
(last data written) to be on the reader page. If more data is written
to the buffer, it is added to the reader page until it falls off back
into the write buffer.
If the system reboots and the commit pointer is still on the reader
page, even if new data was written, the persistent buffer validator
will miss finding the commit pointer because it only checks the write
buffer and does not check the reader page. This causes the validator
to fail the validation and clear the buffer, where the new data is
lost.
There was a check for this, but it checked the "head pointer", which
was incorrect, because the "head pointer" always stays on the write
buffer and is the next page to swap out for the reader page. Fix the
logic to catch this case and allow the user to still read the data
after reboot.
* tag 'trace-v6.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Fix persistent buffer when commit page is the reader page
ftrace: Fix preemption accounting for stacktrace filter command
ftrace: Fix preemption accounting for stacktrace trigger command
tracing: samples: Initialize trace_array_printk() with the correct function
The ring buffer is made up of sub buffers (sometimes called pages as they
are by default PAGE_SIZE). It has the following "pages":
"tail page" - this is the page that the next write will write to
"head page" - this is the page that the reader will swap the reader page with.
"reader page" - This belongs to the reader, where it will swap the head
page from the ring buffer so that the reader does not
race with the writer.
The writer may end up on the "reader page" if the ring buffer hasn't
written more than one page, where the "tail page" and the "head page" are
the same.
The persistent ring buffer has meta data that points to where these pages
exist so on reboot it can re-create the pointers to the cpu_buffer
descriptor. But when the commit page is on the reader page, the logic is
incorrect.
The check to see if the commit page is on the reader page checked if the
head page was the reader page, which would never happen, as the head page
is always in the ring buffer. The correct check would be to test if the
commit page is on the reader page. If that's the case, then it can exit
out early as the commit page is only on the reader page when there's only
one page of data in the buffer. There's no reason to iterate the ring
buffer pages to find the "commit page" as it is already found.
To trigger this bug:
# echo 1 > /sys/kernel/tracing/instances/boot_mapped/events/syscalls/sys_enter_fchownat/enable
# touch /tmp/x
# chown sshd /tmp/x
# reboot
On boot up, the dmesg will have:
Ring buffer meta [0] is from previous boot!
Ring buffer meta [1] is from previous boot!
Ring buffer meta [2] is from previous boot!
Ring buffer meta [3] is from previous boot!
Ring buffer meta [4] commit page not found
Ring buffer meta [5] is from previous boot!
Ring buffer meta [6] is from previous boot!
Ring buffer meta [7] is from previous boot!
Where the buffer on CPU 4 had a "commit page not found" error and that
buffer is cleared and reset causing the output to be empty and the data lost.
When it works correctly, it has:
# cat /sys/kernel/tracing/instances/boot_mapped/trace_pipe
<...>-1137 [004] ..... 998.205323: sys_enter_fchownat: __syscall_nr=0x104 (260) dfd=0xffffff9c (4294967196) filename=(0xffffc90000a0002c) user=0x3e8 (1000) group=0xffffffff (4294967295) flag=0x0 (0
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250513115032.3e0b97f7@gandalf.local.home
Fixes: 5f3b6e839f ("ring-buffer: Validate boot range memory events")
Reported-by: Tasos Sahanidis <tasos@tasossah.com>
Tested-by: Tasos Sahanidis <tasos@tasossah.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When using the stacktrace trigger command to trace syscalls, the
preemption count was consistently reported as 1 when the system call
event itself had 0 (".").
For example:
root@ubuntu22-vm:/sys/kernel/tracing/events/syscalls/sys_enter_read
$ echo stacktrace > trigger
$ echo 1 > enable
sshd-416 [002] ..... 232.864910: sys_read(fd: a, buf: 556b1f3221d0, count: 8000)
sshd-416 [002] ...1. 232.864913: <stack trace>
=> ftrace_syscall_enter
=> syscall_trace_enter
=> do_syscall_64
=> entry_SYSCALL_64_after_hwframe
The root cause is that the trace framework disables preemption in __DO_TRACE before
invoking the trigger callback.
Use the tracing_gen_ctx_dec() that will accommodate for the increase of
the preemption count in __DO_TRACE when calling the callback. The result
is the accurate reporting of:
sshd-410 [004] ..... 210.117660: sys_read(fd: 4, buf: 559b725ba130, count: 40000)
sshd-410 [004] ..... 210.117662: <stack trace>
=> ftrace_syscall_enter
=> syscall_trace_enter
=> do_syscall_64
=> entry_SYSCALL_64_after_hwframe
Cc: stable@vger.kernel.org
Fixes: ce33c845b0 ("tracing: Dump stacktrace trigger to the corresponding instance")
Link: https://lore.kernel.org/20250512094246.1167956-1-dolinux.peng@gmail.com
Signed-off-by: pengdonglin <dolinux.peng@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Record trace_clock information in the trace_scratch area and recover
the trace_clock when boot, so that reader can docode the timestamp
correctly.
Note that since most trace_clocks records the timestamp in nano-
seconds, this is not a bug. But some trace_clock, like counter and
tsc will record the counter value. Only for those trace_clock user
needs this information.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/174720625803.1925039.1815089037443798944.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Instead of find_first_bit() use the dedicated bitmap_empty(),
and make upper_empty() a nice one-liner.
While there, fix opencoded BITS_PER_TYPE().
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250429195119.620204-1-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Since the shared trace_probe_log variable can be accessed and
modified via probe event create operation of kprobe_events,
uprobe_events, and dynamic_events, it should be protected.
In the dynamic_events, all operations are serialized by
`dyn_event_ops_mutex`. But kprobe_events and uprobe_events
interfaces are not serialized.
To solve this issue, introduces dyn_event_create(), which runs
create() operation under the mutex, for kprobe_events and
uprobe_events. This also uses lockdep to check the mutex is
held when using trace_probe_log* APIs.
Link: https://lore.kernel.org/all/174684868120.551552.3068655787654268804.stgit@devnote2/
Reported-by: Paul Cacheux <paulcacheux@gmail.com>
Closes: https://lore.kernel.org/all/20250510074456.805a16872b591e2971a4d221@kernel.org/
Fixes: ab105a4fb8 ("tracing: Use tracing error_log with probe events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
This patch introduces a new set of kfuncs for working with dynptrs in
BPF programs, enabling reading variable-length user or kernel data
into dynptr directly. To enable memory-safety, verifier allows only
constant-sized reads via existing bpf_probe_read_{user|kernel} etc.
kfuncs, dynptr-based kfuncs allow dynamically-sized reads without memory
safety shortcomings.
The following kfuncs are introduced:
* `bpf_probe_read_kernel_dynptr()`: probes kernel-space data into a dynptr
* `bpf_probe_read_user_dynptr()`: probes user-space data into a dynptr
* `bpf_probe_read_kernel_str_dynptr()`: probes kernel-space string into
a dynptr
* `bpf_probe_read_user_str_dynptr()`: probes user-space string into a
dynptr
* `bpf_copy_from_user_dynptr()`: sleepable, copies user-space data into
a dynptr for the current task
* `bpf_copy_from_user_str_dynptr()`: sleepable, copies user-space string
into a dynptr for the current task
* `bpf_copy_from_user_task_dynptr()`: sleepable, copies user-space data
of the task into a dynptr
* `bpf_copy_from_user_task_str_dynptr()`: sleepable, copies user-space
string of the task into a dynptr
The implementation is built on two generic functions:
* __bpf_dynptr_copy
* __bpf_dynptr_copy_str
These functions take function pointers as arguments, enabling the
copying of data from various sources, including both kernel and user
space.
Use __always_inline for generic functions and callbacks to make sure the
compiler doesn't generate indirect calls into callbacks, which is more
expensive, especially on some kernel configurations. Inlining allows
compiler to put direct calls into all the specific callback implementations
(copy_user_data_sleepable, copy_user_data_nofault, and so on).
Reviewed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20250512205348.191079-3-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Make sure trace_probe_log_clear is called in the tracing
eprobe code path, matching the trace_probe_log_init call.
Link: https://lore.kernel.org/all/20250504-fix-trace-probe-log-race-v3-1-9e99fec7eddc@gmail.com/
Signed-off-by: Paul Cacheux <paulcacheux@gmail.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
When CONFIG_PROVE_RCU_LIST is enabled, fprobe triggers the following
warning:
WARNING: suspicious RCU usage
kernel/trace/fprobe.c:457 RCU-list traversed in non-reader section!!
other info that might help us debug this:
#1: ffffffff863c4e08 (fprobe_mutex){+.+.}-{4:4}, at: fprobe_module_callback+0x7b/0x8c0
Call Trace:
fprobe_module_callback
notifier_call_chain
blocking_notifier_call_chain
This warning occurs because fprobe_remove_node_in_module() traverses an
RCU list using RCU primitives without holding an RCU read lock. However,
the function is only called from fprobe_module_callback(), which holds
the fprobe_mutex lock that provides sufficient protection for safely
traversing the list.
Fix the warning by specifying the locking design to the
CONFIG_PROVE_RCU_LIST mechanism. Add the lockdep_is_held() argument to
hlist_for_each_entry_rcu() to inform the RCU checker that fprobe_mutex
provides the required protection.
Link: https://lore.kernel.org/all/20250410-fprobe-v1-1-068ef5f41436@debian.org/
Fixes: a3dc2983ca ("tracing: fprobe: Cleanup fprobe hash when module unloading")
Signed-off-by: Breno Leitao <leitao@debian.org>
Tested-by: Antonio Quartulli <antonio@mandelbit.com>
Tested-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Adding support to retrieve ref_ctr_offset for uprobe perf link,
which got somehow omitted from the initial uprobe link info changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/bpf/20250509153539.779599-2-jolsa@kernel.org
There are applications that have it hard coded to write into the top level
trace_marker instance (/sys/kernel/tracing/trace_marker). This can be
annoying if a profiler is using that instance for other work, or if it
needs all writes to go into a new instance.
A new option is created called "copy_trace_marker". By default, the top
level has this set, as that is the default buffer that writing into the
top level trace_marker file will go to. But now if an instance is created
and sets this option, all writes into the top level trace_marker will also
be written into that instance buffer just as if an application were to
write into the instance's trace_marker file.
If the top level instance disables this option, then writes to its own
trace_marker and trace_marker_raw files will not go into its buffer.
If no instance has this option set, then the write will return an error
and errno will contain ENODEV.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250508095639.39f84eda@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add a helper function called handle_dereference_arg() to replace the logic
that is identical in two locations of test_event_printk().
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250507191703.5dd8a61d@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
There's several functions that have "goto out;" where the label out is just:
out:
return ret;
Simplify the code by just doing the return in the location and removing
all the out labels and jumps.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://lore.kernel.org/20250507145456.121186494@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
According to trigger_data_alloc() doc, trigger_data_free() should be
used to free an event_trigger_data object. This fixes a mismatch introduced
when kzalloc was replaced with trigger_data_alloc without updating
the corresponding deallocation calls.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://lore.kernel.org/20250507145455.944453325@goodmis.org
Link: https://lore.kernel.org/20250318112737.4174-1-linmq006@gmail.com
Fixes: e1f187d09e ("tracing: Have existing event_command.parse() implementations use helpers")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
[ SDR: Changed event_trigger_alloc/free() to trigger_data_alloc/free() ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function event_trigger_alloc() creates an event_trigger_data
descriptor and states that it needs to be freed via event_trigger_free().
This is incorrect, it needs to be freed by trigger_data_free() as
event_trigger_free() adds ref counting.
Rename event_trigger_alloc() to trigger_data_alloc() and state that it
needs to be freed via trigger_data_free(). This naming convention
was introducing bugs.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://lore.kernel.org/20250507145455.776436410@goodmis.org
Fixes: 86599dbe2c ("tracing: Add helper functions to simplify event_command.parse() callback handling")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The trace_array_cpu had a "buffer_page" field that was originally going to
be used as a backup page for the ring buffer. But the ring buffer has its
own way of reusing pages and this field was never used.
Remove it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.738849456@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The irqsoff tracer uses the per CPU "disabled" field to prevent corruption
of the accounting when it starts to trace interrupts disabled, but there's
a slight race that could happen if for some reason it was called twice.
Use atomic_inc_return() instead.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.567884756@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" counter is used for the latency tracers and stack
tracers to make sure that their accounting isn't messed up by an NMI or
interrupt coming in and affecting the same CPU data. But the counter is an
atomic_t type. As it only needs to synchronize against the current CPU,
switch it over to local_t type.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.394925376@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The branch tracer currently checks the per CPU "disabled" field to know if
tracing is enabled or not for the CPU. As the "disabled" value is not used
anymore to turn of tracing generically, use tracing_tracer_is_on_cpu()
instead.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.224658526@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add the function ring_buffer_record_is_on_cpu() that returns true if the
ring buffer for a give CPU is writable and false otherwise.
Also add tracer_tracing_is_on_cpu() to return if the ring buffer for a
given CPU is writeable for a given trace_array.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212236.059853898@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
Do not bother setting the per CPU disabled flag of the array_buffer data
to use to determine what CPUs can write to the buffer and only rely on the
ring buffer code itself to disabled it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212235.885452497@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
Do not bother disabling the function graph tracer if the per CPU disabled
field is set. Just record as normal. If tracing is disabled in the ring
buffer it will not be recorded.
Also, when tracing is enabled again, it will not drop the return call of
the function.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212235.715752008@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
The kdb_ftdump() function iterates over all the current tracing CPUs and
increments the "disabled" counter before doing the dump, and decrements it
afterward.
As the disabled flag can be ignored, doing this today is not reliable.
Instead, simply call tracer_tracing_off() and then tracer_tracing_on() to
disable and then enabled the entire ring buffer in one go!
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Thompson <danielt@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/20250505212235.549033722@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
The ftrace_dump_one() function iterates over all the current tracing CPUs and
increments the "disabled" counter before doing the dump, and decrements it
afterward.
As the disabled flag can be ignored, doing this today is not reliable.
Instead use the new tracer_tracing_disable() that calls into the ring
buffer code to do the disabling.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212235.381188238@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Allow a tracer to disable writing to its buffer for a temporary amount of
time and re-enable it.
The tracer_tracing_disable() will disable writing to the trace array
buffer, and requires a tracer_tracing_enable() to re-enable it.
The difference between tracer_tracing_disable() and tracer_tracing_off()
is that the disable version can nest, and requires as many enable() calls
as disable() calls to re-enable the buffer. Where as the off() function
can be called multiple times and only requires a singe tracer_tracing_on()
to re-enable the buffer.
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daniel Thompson <danielt@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/20250505212235.210330010@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The ignore_pid boolean on the per CPU data descriptor is updated at
sched_switch when a new task is scheduled in. If the new task is to be
ignored, it is set to true, otherwise it is set to false. The current task
should always have the correct value as it is updated when the task is
scheduled in.
Instead of breaking up the read of this value, which requires preemption
to be disabled, just use this_cpu_read() which gives a snapshot of the
value. Since the value will always be correct for a given task (because
it's updated at sched switch) it doesn't need preemption disabled.
This will also allow trace events to be called with preemption enabled.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212235.038958766@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The per CPU "disabled" value was the original way to disable tracing when
the tracing subsystem was first created. Today, the ring buffer
infrastructure has its own way to disable tracing. In fact, things have
changed so much since 2008 that many things ignore the disable flag.
There's no reason for the function tracer to check it, if tracing is
disabled, the ring buffer will not record the event anyway.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212234.868972758@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The mmiotracer referenced the per CPU array_buffer->data descriptor but
never actually used it. Remove the references to it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250505212234.696945463@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Allocate kernel memory for processing CPU string
(/sys/kernel/tracing/osnoise/cpus) also in osnoise_cpus_write to allow
the writing of a CPU string of an arbitrary length.
This replaces the 256-byte buffer, which is insufficient with the rising
number of CPUs. For example, if I wanted to measure on every even CPU
on a system with 256 CPUs, the string would be 456 characters long.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250425091839.343289-1-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The structure ftrace_func_mapper only contains a single field and that is
a ftrace_hash. It is used to abstract it out from a normal hash to control
users of how it gets modified.
The freeing of a ftrace_func_mapper structure is:
free_ftrace_hash(&mapper->hash);
Without context, this looks like a bug. It should be commented that it is
not a bug and it is freed this way.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/20250416165420.5c717420@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Depth is stored as int because the code uses negative values to break
out of iterations. But what is recorded is always zero or positive. So
expose it as unsigned int instead of int.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250412221847.17310-3-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function graph infrastructure uses subops of the function tracer.
These are not shown in enabled_functions. Add a "subops:" section to the
enabled_functions line to show what functions are attached via subops. If
the subops is from the function_graph infrastructure, then show the entry
and return callbacks that are attached.
Here's an example of the output:
schedule_on_each_cpu (1) tramp: 0xffffffffc03ef000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60 subops: {ent:trace_graph_entry+0x0/0x20 ret:trace_graph_return+0x0/0x150}
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250410153830.5d97f108@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The last remaining user of vfs_submount() (tracefs) is easy to convert
to fs_context_for_submount(); do that and bury that thing, along with
SB_SUBMOUNT
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If one wants to trace the name of the task that wakes up a process and
pass that to the synthetic events, there's nothing currently that lets the
synthetic events do that. Add a "common_comm" to the histogram logic that
allows histograms save the current->comm as a variable that can be passed
through and added to a synthetic event:
# cd /sys/kernel/tracing
# echo 's:wake_lat char[] waker; char[] wakee; u64 delta;' >> dynamic_events
# echo 'hist:keys=pid:comm=common_comm:ts=common_timestamp.usecs if !(common_flags & 0x18)' > events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:wake_comm=$comm:delta=common_timestamp.usecs-$ts:onmatch(sched.sched_waking).trace(wake_lat,$wake_comm,next_comm,$delta)' > events/sched/sched_switch/trigger
The above will create a synthetic trace event that will save both the name
of the waker and the wakee but only if the wakeup did not happen in a hard
or soft interrupt context.
The "common_comm" is used to save the task->comm at the time of the
initial event and is passed via the "comm" variable to the second event,
and that is saved as the "waker" field in the "wake_lat" synthetic event.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250407154912.3c6c6246@gandalf.local.home
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The histogram trigger has three somewhat large arrays on the kernel stack:
unsigned long entries[HIST_STACKTRACE_DEPTH];
u64 var_ref_vals[TRACING_MAP_VARS_MAX];
char compound_key[HIST_KEY_SIZE_MAX];
Checking the function event_hist_trigger() stack frame size, it currently
uses 816 bytes for its stack frame due to these variables!
Instead, allocate a per CPU structure that holds these arrays for each
context level (normal, softirq, irq and NMI). That is, each CPU will have
4 of these structures. This will be allocated when the first histogram
trigger is enabled and freed when the last is disabled. When the
histogram callback triggers, it will request this structure. The request
will disable preemption, get the per CPU structure at the index of the
per CPU variable, and increment that variable.
The callback will use the arrays in this structure to perform its work and
then release the structure. That in turn will simply decrement the per CPU
index and enable preemption.
Moving the variables from the kernel stack to the per CPU structure brings
the stack frame of event_hist_trigger() down to just 112 bytes.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://lore.kernel.org/20250407123851.74ea8d58@gandalf.local.home
Fixes: 067fe038e7 ("tracing: Add variable reference handling to hist triggers")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The add_to_key() function tests if the key is a string or some data. If
it's a string it does some further calculations of the string size (still
truncating it to the max size it can be), and calls strncpy().
If the key isn't as string it calls memcpy(). The interesting point is
that both use the exact same parameters:
strncpy(compound_key + key_field->offset, (char *)key, size);
} else
memcpy(compound_key + key_field->offset, key, size);
As strncpy() is being used simply as a memcpy() for a string, and since
strncpy() is deprecated, just call memcpy() for both memory and string
keys.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/20250403210637.1c477d4a@gandalf.local.home
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When the "fields" option is set in a trace instance, it ignores the "print fmt"
portion of the trace event and just prints the raw fields defined by the
TP_STRUCT__entry() of the TRACE_EVENT() macro.
The preempt_disable/enable and irq_disable/enable events record only the
caller offset from _stext to save space in the ring buffer. Even though
the "fields" option only prints the fields, it also tries to print what
they represent too, which includes function names.
Add a check in the output of the event field printing to see if the field
name is "caller_offs" or "parent_offs" and then print the function at the
offset from _stext of that field.
Instead of just showing:
irq_disable: caller_offs=0xba634d (12215117) parent_offs=0x39d10e2 (60625122)
Show:
irq_disable: caller_offs=trace_hardirqs_off.part.0+0xad/0x130 0xba634d (12215117) parent_offs=_raw_spin_lock_irqsave+0x62/0x70 0x39d10e2 (60625122)
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250506105131.4b6089a9@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add adjustments to the values of the "fields" output if the buffer is a
persistent ring buffer to adjust the addresses to both the kernel core and
kernel modules if they match a module in the persistent memory and that
module is also loaded.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250325185619.54b85587@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The trace_adjust_address() will take a given address and examine the
persistent ring buffer to see if the address matches a module that is
listed there. If it does not, it will just adjust the value to the core
kernel delta. But if the address was for something that was not part of
the core kernel text or data it should not be adjusted.
Check the result of the adjustment and only return the adjustment if it
lands in the current kernel text or data. If not, return the original
address.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250506102300.0ba2f9e0@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When the "fields" option is enabled, the "print fmt" of the trace event is
ignored and only the fields are printed. But some fields contain function
pointers. Instead of just showing the hex value in this case, show the
function name when possible:
Instead of having:
# echo 1 > options/fields
# cat trace
[..]
kmem_cache_free: call_site=0xffffffffa9afcf31 (-1448095951) ptr=0xffff888124452910 (-131386736039664) name=kmemleak_object
Have it output:
kmem_cache_free: call_site=rcu_do_batch+0x3d1/0x14a0 (-1768960207) ptr=0xffff888132ea5ed0 (854220496) name=kmemleak_object
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250325213919.624181915@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Now that module addresses are saved in the persistent ring buffer, their
addresses can be used to adjust the address in the persistent ring buffer
to the address of the module that is currently loaded.
Instead of blindly using the text_delta that only works for core kernel
code, call the trace_adjust_address() that will see if the address matches
an address saved in the persistent ring buffer, and then uses that against
the matching module if it is loaded.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250506111648.5df7f3ec@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The block layer bounce buffering support is unused now, remove it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20250505081138.3435992-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently the calling conventions for ->d_automount() instances have
an odd wart - returned new mount to be attached is expected to have
refcount 2.
That kludge is intended to make sure that mark_mounts_for_expiry() called
before we get around to attaching that new mount to the tree won't decide
to take it out. finish_automount() drops the extra reference after it's
done with attaching mount to the tree - or drops the reference twice in
case of error. ->d_automount() instances have rather counterintuitive
boilerplate in them.
There's a much simpler approach: have mark_mounts_for_expiry() skip the
mounts that are yet to be mounted. And to hell with grabbing/dropping
those extra references. Makes for simpler correctness analysis, at that...
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Acked-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The function trace_adjust_address() is used to map addresses of modules
stored in the persistent memory and are also loaded in the current boot to
return the current address for the module.
If there's only one module entry, it will simply use that, otherwise it
performs a bsearch of the entry array to find the modules to offset with.
The issue is if there are no modules in the array. The code does not
account for that and ends up referencing the first element in the array
which does not exist and causes a crash.
If nr_entries is zero, exit out early as if this was a core kernel
address.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250501151909.65910359@gandalf.local.home
Fixes: 35a380ddbc ("tracing: Show last module text symbols in the stacktrace")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The check for a failed memory location is incorrectly checking
the wrong level of pointer indirection by checking !filter_hash
rather than !*filter_hash. Fix this.
Cc: asami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250422221335.89896-1-colin.i.king@gmail.com
Fixes: 0ae6b8ce20 ("ftrace: Fix accounting of subop hashes")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
syzbot reported this bug:
==================================================================
BUG: KASAN: slab-out-of-bounds in trace_seq_to_buffer kernel/trace/trace.c:1830 [inline]
BUG: KASAN: slab-out-of-bounds in tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822
Write of size 4507 at addr ffff888032b6b000 by task syz.2.320/7260
CPU: 1 UID: 0 PID: 7260 Comm: syz.2.320 Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xc3/0x670 mm/kasan/report.c:521
kasan_report+0xe0/0x110 mm/kasan/report.c:634
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
__asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106
trace_seq_to_buffer kernel/trace/trace.c:1830 [inline]
tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822
....
==================================================================
It has been reported that trace_seq_to_buffer() tries to copy more data
than PAGE_SIZE to buf. Therefore, to prevent this, we should use the
smaller of trace_seq_used(&iter->seq) and PAGE_SIZE as an argument.
Link: https://lore.kernel.org/20250422113026.13308-1-aha310510@gmail.com
Reported-by: syzbot+c8cd2d2c412b868263fb@syzkaller.appspotmail.com
Fixes: 3c56819b14 ("tracing: splice support for tracing_pipe")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Many conditional checks in switch-case are redundant
with bpf_base_func_proto and should be removed.
Regarding the permission checks bpf_base_func_proto:
The permission checks in bpf_prog_load (as outlined below)
ensure that the trace has both CAP_BPF and CAP_PERFMON capabilities,
thus enabling the use of corresponding prototypes
in bpf_base_func_proto without adverse effects.
bpf_prog_load
......
bpf_cap = bpf_token_capable(token, CAP_BPF);
......
if (type != BPF_PROG_TYPE_SOCKET_FILTER &&
type != BPF_PROG_TYPE_CGROUP_SKB &&
!bpf_cap)
goto put_token;
......
if (is_perfmon_prog_type(type) && !bpf_token_capable(token, CAP_PERFMON))
goto put_token;
......
Signed-off-by: Feng Yang <yangfeng@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20250423073151.297103-1-yangfeng59949@163.com
The filter string testing uses strncpy_from_kernel/user_nofault() to
retrieve the string to test the filter against. The if() statement was
incorrect as it considered 0 as a fault, when it is only negative that it
faulted.
Running the following commands:
# cd /sys/kernel/tracing
# echo "filename.ustring ~ \"/proc*\"" > events/syscalls/sys_enter_openat/filter
# echo 1 > events/syscalls/sys_enter_openat/enable
# ls /proc/$$/maps
# cat trace
Would produce nothing, but with the fix it will produce something like:
ls-1192 [007] ..... 8169.828333: sys_openat(dfd: ffffffffffffff9c, filename: 7efc18359904, flags: 80000, mode: 0)
Link: https://lore.kernel.org/all/CAEf4BzbVPQ=BjWztmEwBPRKHUwNfKBkS3kce-Rzka6zvbQeVpg@mail.gmail.com/
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250417183003.505835fb@gandalf.local.home
Fixes: 77360f9bbc ("tracing: Add test for user space strings when filtering on string pointers")
Reported-by: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Reported-by: Mykyta Yatsenko <mykyta.yatsenko5@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
ftrace_graph_ent.depth is int, but ftrace_graph_ent_entry.depth is
unsigned long. This confuses trace-cmd on 64-bit big-endian systems and
makes it print a huge amount of spaces. Fix this by using unsigned int,
which has a matching size, instead.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250412221847.17310-2-iii@linux.ibm.com
Fixes: ff5c9c576e ("ftrace: Add support for function argument to graph tracer")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The maximum of the ftrace hash bits is made fls(32) in
register_ftrace_direct(), which seems illogical. So, we fix it by making
the max hash bits FTRACE_HASH_MAX_BITS instead.
Link: https://lore.kernel.org/20250413014444.36724-1-dongml2@chinatelecom.cn
Fixes: d05cb47066 ("ftrace: Fix modification of direct_function hash while in use")
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The subops processing creates new hashes when adding and removing subops.
There were some places that the old hashes that were replaced were not
freed and this caused some memory leaks.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250417135939.245b128d@gandalf.local.home
Fixes: 0ae6b8ce20 ("ftrace: Fix accounting of subop hashes")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
There's several locations that free a ftrace hash pointer but may be
referenced again. Reset them to EMPTY_HASH so that a u-a-f bug doesn't
happen.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250417110933.20ab718b@gandalf.local.home
Fixes: 0ae6b8ce20 ("ftrace: Fix accounting of subop hashes")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The reworking to fix and simplify the ftrace_startup_subops() and the
ftrace_shutdown_subops() made it possible for the filter_hash and
notrace_hash variables to be used uninitialized in a way that the compiler
did not catch it.
Initialize both filter_hash and notrace_hash to the EMPTY_HASH as that is
what they should be if they never are used.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250417104017.3aea66c2@gandalf.local.home
Reported-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Fixes: 0ae6b8ce20 ("ftrace: Fix accounting of subop hashes")
Closes: https://lore.kernel.org/all/1db64a42-626d-4b3a-be08-c65e47333ce2@linux.ibm.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Hide get_vm_area() from MMUless builds
The function get_vm_area() is not defined when CONFIG_MMU is not defined.
Hide that function within #ifdef CONFIG_MMU.
- Fix output of synthetic events when they have dynamic strings
The print fmt of the synthetic event's format file use to have "%.*s" for
dynamic size strings even though the user space exported arguments had
only __get_str() macro that provided just a nul terminated string. This
was fixed so that user space could parse this properly. But the reason
that it had "%.*s" was because internally it provided the maximum size of
the string as one of the arguments. The fix that replaced "%.*s" with "%s"
caused the trace output (when the kernel reads the event) to write
"(efault)" as it would now read the length of the string as "%s".
As the string provided is always nul terminated, there's no reason for the
internal code to use "%.*s" anyway. Just remove the length argument to
match the "%s" that is now in the format.
- Fix the ftrace subops hash logic of the manager ops hash
The function_graph uses the ftrace subops code. The subops code is a way
to have a single ftrace_ops registered with ftrace to determine what
functions will call the ftrace_ops callback. More than one user of
function graph can register a ftrace_ops with it. The function graph
infrastructure will then add this ftrace_ops as a subops with the main
ftrace_ops it registers with ftrace. This is because the functions will
always call the function graph callback which in turn calls the subops
ftrace_ops callbacks.
The main ftrace_ops must add a callback to all the functions that the
subops want a callback from. When a subops is registered, it will update
the main ftrace_ops hash to include the functions it wants. This is the
logic that was broken.
The ftrace_ops hash has a "filter_hash" and a "notrace_hash" were all the
functions in the filter_hash but not in the notrace_hash are attached by
ftrace. The original logic would have the main ftrace_ops filter_hash be a
union of all the subops filter_hashes and the main notrace_hash would be a
intersect of all the subops filter hashes. But this was incorrect because
the notrace hash depends on the filter_hash it is associated to and not
the union of all filter_hashes.
Instead, when a subops is added, just include all the functions of the
subops hash that are in its filter_hash but not in its notrace_hash. The
main subops hash should not use its notrace hash, unless all of its subops
hashes have an empty filter_hash (which means to attach to all functions),
and then, and only then, the main ftrace_ops notrace hash can be the
intersect of all the subops hashes.
This not only fixes the bug, but also simplifies the code.
- Add a selftest to better test the subops filtering
Add a selftest that would catch the bug fixed by the above change.
- Fix extra newline printed in function tracing with retval
The function parameter code changed the output logic slightly and called
print_graph_retval() and also printed a newline. The print_graph_retval()
also prints a newline which caused blank lines to be printed in the
function graph tracer when retval was added. This caused one of the
selftests to fail if retvals were enabled. Instead remove the new line
output from print_graph_retval() and have the callers always print the
new line so that it doesn't have to do special logic if it calls
print_graph_retval() or not.
- Fix out-of-bound memory access in the runtime verifier
When rv_is_container_monitor() is called on the last entry on the link
list it references the next entry, which is the list head and causes an
out-of-bound memory access.
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Merge tag 'trace-v6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Hide get_vm_area() from MMUless builds
The function get_vm_area() is not defined when CONFIG_MMU is not
defined. Hide that function within #ifdef CONFIG_MMU.
- Fix output of synthetic events when they have dynamic strings
The print fmt of the synthetic event's format file use to have "%.*s"
for dynamic size strings even though the user space exported
arguments had only __get_str() macro that provided just a nul
terminated string. This was fixed so that user space could parse this
properly.
But the reason that it had "%.*s" was because internally it provided
the maximum size of the string as one of the arguments. The fix that
replaced "%.*s" with "%s" caused the trace output (when the kernel
reads the event) to write "(efault)" as it would now read the length
of the string as "%s".
As the string provided is always nul terminated, there's no reason
for the internal code to use "%.*s" anyway. Just remove the length
argument to match the "%s" that is now in the format.
- Fix the ftrace subops hash logic of the manager ops hash
The function_graph uses the ftrace subops code. The subops code is a
way to have a single ftrace_ops registered with ftrace to determine
what functions will call the ftrace_ops callback. More than one user
of function graph can register a ftrace_ops with it. The function
graph infrastructure will then add this ftrace_ops as a subops with
the main ftrace_ops it registers with ftrace. This is because the
functions will always call the function graph callback which in turn
calls the subops ftrace_ops callbacks.
The main ftrace_ops must add a callback to all the functions that the
subops want a callback from. When a subops is registered, it will
update the main ftrace_ops hash to include the functions it wants.
This is the logic that was broken.
The ftrace_ops hash has a "filter_hash" and a "notrace_hash" where
all the functions in the filter_hash but not in the notrace_hash are
attached by ftrace. The original logic would have the main ftrace_ops
filter_hash be a union of all the subops filter_hashes and the main
notrace_hash would be a intersect of all the subops filter hashes.
But this was incorrect because the notrace hash depends on the
filter_hash it is associated to and not the union of all
filter_hashes.
Instead, when a subops is added, just include all the functions of
the subops hash that are in its filter_hash but not in its
notrace_hash. The main subops hash should not use its notrace hash,
unless all of its subops hashes have an empty filter_hash (which
means to attach to all functions), and then, and only then, the main
ftrace_ops notrace hash can be the intersect of all the subops
hashes.
This not only fixes the bug, but also simplifies the code.
- Add a selftest to better test the subops filtering
Add a selftest that would catch the bug fixed by the above change.
- Fix extra newline printed in function tracing with retval
The function parameter code changed the output logic slightly and
called print_graph_retval() and also printed a newline. The
print_graph_retval() also prints a newline which caused blank lines
to be printed in the function graph tracer when retval was added.
This caused one of the selftests to fail if retvals were enabled.
Instead remove the new line output from print_graph_retval() and have
the callers always print the new line so that it doesn't have to do
special logic if it calls print_graph_retval() or not.
- Fix out-of-bound memory access in the runtime verifier
When rv_is_container_monitor() is called on the last entry on the
link list it references the next entry, which is the list head and
causes an out-of-bound memory access.
* tag 'trace-v6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
rv: Fix out-of-bound memory access in rv_is_container_monitor()
ftrace: Do not have print_graph_retval() add a newline
tracing/selftest: Add test to better test subops filtering of function graph
ftrace: Fix accounting of subop hashes
ftrace: Properly merge notrace hashes
tracing: Do not add length to print format in synthetic events
tracing: Hide get_vm_area() from MMUless builds
When rv_is_container_monitor() is called on the last monitor in
rv_monitors_list, KASAN yells:
BUG: KASAN: global-out-of-bounds in rv_is_container_monitor+0x101/0x110
Read of size 8 at addr ffffffff97c7c798 by task setup/221
The buggy address belongs to the variable:
rv_monitors_list+0x18/0x40
This is due to list_next_entry() is called on the last entry in the list.
It wraps around to the first list_head, and the first list_head is not
embedded in struct rv_monitor_def.
Fix it by checking if the monitor is last in the list.
Cc: stable@vger.kernel.org
Cc: Gabriele Monaco <gmonaco@redhat.com>
Fixes: cb85c660fc ("rv: Add option for nested monitors and include sched")
Link: https://lore.kernel.org/e85b5eeb7228bfc23b8d7d4ab5411472c54ae91b.1744355018.git.namcao@linutronix.de
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The retval and retaddr options for function_graph tracer will add a
comment at the end of a function for both leaf and non leaf functions that
looks like:
__wake_up_common(); /* ret=0x1 */
} /* pick_next_task_fair ret=0x0 */
The function print_graph_retval() adds a newline after the "*/". But if
that's not called, the caller function needs to make sure there's a
newline added.
This is confusing and when the function parameters code was added, it
added a newline even when calling print_graph_retval() as the fact that
the print_graph_retval() function prints a newline isn't obvious.
This caused an extra newline to be printed and that made it fail the
selftests when the retval option was set, as the selftests were not
expecting blank lines being injected into the trace.
Instead of having print_graph_retval() print a newline, just have the
caller always print the newline regardless if it calls print_graph_retval()
or not. This not only fixes this bug, but it also simplifies the code.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250411133015.015ca393@gandalf.local.home
Reported-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Closes: https://lore.kernel.org/all/ccc40f2b-4b9e-4abd-8daf-d22fce2a86f0@sirena.org.uk/
Fixes: ff5c9c576e ("ftrace: Add support for function argument to graph tracer")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function graph infrastructure uses ftrace to hook to functions. It has
a single ftrace_ops to manage all the users of function graph. Each
individual user (tracing, bpf, fprobes, etc) has its own ftrace_ops to
track the functions it will have its callback called from. These
ftrace_ops are "subops" to the main ftrace_ops of the function graph
infrastructure.
Each ftrace_ops has a filter_hash and a notrace_hash that is defined as:
Only trace functions that are in the filter_hash but not in the
notrace_hash.
If the filter_hash is empty, it means to trace all functions.
If the notrace_hash is empty, it means do not disable any function.
The function graph main ftrace_ops needs to be a superset containing all
the functions to be traced by all the subops it has. The algorithm to
perform this merge was incorrect.
When the first subops was added to the main ops, it simply made the main
ops a copy of the subops (same filter_hash and notrace_hash).
When a second ops was added, it joined the new subops filter_hash with the
main ops filter_hash as a union of the two sets. The intersect between the
new subops notrace_hash and the main ops notrace_hash was created as the
new notrace_hash of the main ops.
The issue here is that it would then start tracing functions than no
subops were tracing. For example if you had two subops that had:
subops 1:
filter_hash = '*sched*' # trace all functions with "sched" in it
notrace_hash = '*time*' # except do not trace functions with "time"
subops 2:
filter_hash = '*lock*' # trace all functions with "lock" in it
notrace_hash = '*clock*' # except do not trace functions with "clock"
The intersect of '*time*' functions with '*clock*' functions could be the
empty set. That means the main ops will be tracing all functions with
'*time*' and all "*clock*" in it!
Instead, modify the algorithm to be a bit simpler and correct.
First, when adding a new subops, even if it's the first one, do not add
the notrace_hash if the filter_hash is not empty. Instead, just add the
functions that are in the filter_hash of the subops but not in the
notrace_hash of the subops into the main ops filter_hash. There's no
reason to add anything to the main ops notrace_hash.
The notrace_hash of the main ops should only be non empty iff all subops
filter_hashes are empty (meaning to trace all functions) and all subops
notrace_hashes include the same functions.
That is, the main ops notrace_hash is empty if any subops filter_hash is
non empty.
The main ops notrace_hash only has content in it if all subops
filter_hashes are empty, and the content are only functions that intersect
all the subops notrace_hashes. If any subops notrace_hash is empty, then
so is the main ops notrace_hash.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Andy Chiu <andybnac@gmail.com>
Link: https://lore.kernel.org/20250409152720.216356767@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The global notrace hash should be jointly decided by the intersection of
each subops's notrace hash, but not the filter hash.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250408160258.48563-1-andybnac@gmail.com
Fixes: 5fccc7552c ("ftrace: Add subops logic to allow one ops to manage many")
Signed-off-by: Andy Chiu <andybnac@gmail.com>
[ fixed removing of freeing of filter_hash ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The link_create.flags are currently not used for multi-uprobes, so return
-EINVAL if it is set, same as for other attach APIs.
We allow target_fd to have an arbitrary value for multi-uprobe, though,
as there are existing users (libbpf) relying on this.
Fixes: 89ae89f53d ("bpf: Add multi uprobe link")
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250407035752.1108927-2-chen.dylane@linux.dev
The link_create.flags are currently not used for multi-kprobes, so return
-EINVAL if it is set, same as for other attach APIs.
We allow target_fd, on the other hand, to have an arbitrary value for
multi-kprobe, as there are existing users (libbpf) relying on this.
Fixes: 0dcac27254 ("bpf: Add multi kprobe link")
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250407035752.1108927-1-chen.dylane@linux.dev
The following causes a vsnprintf fault:
# echo 's:wake_lat char[] wakee; u64 delta;' >> /sys/kernel/tracing/dynamic_events
# echo 'hist:keys=pid:ts=common_timestamp.usecs if !(common_flags & 0x18)' > /sys/kernel/tracing/events/sched/sched_waking/trigger
# echo 'hist:keys=next_pid:delta=common_timestamp.usecs-$ts:onmatch(sched.sched_waking).trace(wake_lat,next_comm,$delta)' > /sys/kernel/tracing/events/sched/sched_switch/trigger
Because the synthetic event's "wakee" field is created as a dynamic string
(even though the string copied is not). The print format to print the
dynamic string changed from "%*s" to "%s" because another location
(__set_synth_event_print_fmt()) exported this to user space, and user
space did not need that. But it is still used in print_synth_event(), and
the output looks like:
<idle>-0 [001] d..5. 193.428167: wake_lat: wakee=(efault)sshd-sessiondelta=155
sshd-session-879 [001] d..5. 193.811080: wake_lat: wakee=(efault)kworker/u34:5delta=58
<idle>-0 [002] d..5. 193.811198: wake_lat: wakee=(efault)bashdelta=91
bash-880 [002] d..5. 193.811371: wake_lat: wakee=(efault)kworker/u35:2delta=21
<idle>-0 [001] d..5. 193.811516: wake_lat: wakee=(efault)sshd-sessiondelta=129
sshd-session-879 [001] d..5. 193.967576: wake_lat: wakee=(efault)kworker/u34:5delta=50
The length isn't needed as the string is always nul terminated. Just print
the string and not add the length (which was hard coded to the max string
length anyway).
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/20250407154139.69955768@gandalf.local.home
Fixes: 4d38328eb4 ("tracing: Fix synth event printk format for str fields");
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Move stack_tracer_enabled into trace_stack_sysctl_table. This is part of
a greater effort to move ctl tables into their respective subsystems
which will reduce the merge conflicts in kernel/sysctl.c.
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
Move trace ctl tables into their own const array in
kernel/trace/trace.c. The sysctl table register is called with
subsys_initcall placing if after its original place in proc_root_init.
This is part of a greater effort to move ctl tables into their
respective subsystems which will reduce the merge conflicts in
kernel/sysctl.c.
Signed-off-by: Joel Granados <joel.granados@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- fprobe: Fix to remove fprobe_hlist_node when module unloading
When a fprobe target module is removed, the fprobe_hlist_node
should be removed from the fprobe's hash table to prevent reusing
accidentally if another module is loaded at the same address.
- fprobe: Fix to lock module while registering fprobe
The module containing the function to be probeed is locked using a
reference counter until the fprobe registration is complete, which
prevents use after free.
- fprobe-events: Fix possible UAF on modules
Basically as same as above, but in the fprobe-events layer we also
need to get module reference counter when we find the tracepoint
in the module.
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Merge tag 'probes-fixes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fixes from Masami Hiramatsu:
- fprobe: remove fprobe_hlist_node when module unloading
When a fprobe target module is removed, the fprobe_hlist_node should
be removed from the fprobe's hash table to prevent reusing
accidentally if another module is loaded at the same address.
- fprobe: lock module while registering fprobe
The module containing the function to be probeed is locked using a
reference counter until the fprobe registration is complete, which
prevents use after free.
- fprobe-events: fix possible UAF on modules
Basically as same as above, but in the fprobe-events layer we also
need to get module reference counter when we find the tracepoint in
the module.
* tag 'probes-fixes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: fprobe: Cleanup fprobe hash when module unloading
tracing: fprobe events: Fix possible UAF on modules
tracing: fprobe: Fix to lock module while registering fprobe
Cleanup fprobe address hash table on module unloading because the
target symbols will be disappeared when unloading module and not
sure the same symbol is mapped on the same address.
Note that this is at least disables the fprobes if a part of target
symbols on the unloaded modules. Unlike kprobes, fprobe does not
re-enable the probe point by itself. To do that, the caller should
take care register/unregister fprobe when loading/unloading modules.
This simplifies the fprobe state managememt related to the module
loading/unloading.
Link: https://lore.kernel.org/all/174343534473.843280.13988101014957210732.stgit@devnote2/
Fixes: 4346ba1604 ("fprobe: Rewrite fprobe on function-graph tracer")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
The function get_vm_area() is not defined for non-MMU builds and causes a
build error if it is used. Hide the map_pages() function around a:
#ifdef CONFIG_MMU
to keep it from being compiled when CONFIG_MMU is not set.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250407120111.2ccc9319@gandalf.local.home
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Closes: https://lore.kernel.org/all/4f8ece8b-8862-4f7c-8ede-febd28f8a9fe@roeck-us.net/
Fixes: 394f3f02de ("tracing: Use vmap_page_range() to map memmap ring buffer")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
It was mistaken that the physical memory returned from "reserve_mem" had to
be vmap()'d to get to it from a virtual address. But reserve_mem already
maps the memory to the virtual address of the kernel so a simple
phys_to_virt() can be used to get to the virtual address from the physical
memory returned by "reserve_mem". With this new found knowledge, the
code can be cleaned up and simplified.
- Enforce that the persistent memory is page aligned
As the buffers using the persistent memory are all going to be
mapped via pages, make sure that the memory given to the tracing
infrastructure is page aligned. If it is not, it will print a warning
and fail to map the buffer.
- Use phys_to_virt() to get the virtual address from reserve_mem
Instead of calling vmap() on the physical memory returned from
"reserve_mem", use phys_to_virt() instead.
As the memory returned by "memmap" or any other means where a physical
address is given to the tracing infrastructure, it still needs to
be vmap(). Since this memory can never be returned back to the buddy
allocator nor should it ever be memmory mapped to user space, flag
this buffer and up the ref count. The ref count will keep it from
ever being freed, and the flag will prevent it from ever being memory
mapped to user space.
- Use vmap_page_range() for memmap virtual address mapping
For the memmap buffer, instead of allocating an array of struct pages,
assigning them to the contiguous phsycial memory and then passing that to
vmap(), use vmap_page_range() instead
- Replace flush_dcache_folio() with flush_kernel_vmap_range()
Instead of calling virt_to_folio() and passing that to
flush_dcache_folio(), just call flush_kernel_vmap_range() directly.
This also fixes a bug where if a subbuffer was bigger than PAGE_SIZE
only the PAGE_SIZE portion would be flushed.
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Merge tag 'trace-ringbuffer-v6.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer updates from Steven Rostedt:
"Persistent buffer cleanups and simplifications.
It was mistaken that the physical memory returned from "reserve_mem"
had to be vmap()'d to get to it from a virtual address. But
reserve_mem already maps the memory to the virtual address of the
kernel so a simple phys_to_virt() can be used to get to the virtual
address from the physical memory returned by "reserve_mem". With this
new found knowledge, the code can be cleaned up and simplified.
- Enforce that the persistent memory is page aligned
As the buffers using the persistent memory are all going to be
mapped via pages, make sure that the memory given to the tracing
infrastructure is page aligned. If it is not, it will print a
warning and fail to map the buffer.
- Use phys_to_virt() to get the virtual address from reserve_mem
Instead of calling vmap() on the physical memory returned from
"reserve_mem", use phys_to_virt() instead.
As the memory returned by "memmap" or any other means where a
physical address is given to the tracing infrastructure, it still
needs to be vmap(). Since this memory can never be returned back to
the buddy allocator nor should it ever be memmory mapped to user
space, flag this buffer and up the ref count. The ref count will
keep it from ever being freed, and the flag will prevent it from
ever being memory mapped to user space.
- Use vmap_page_range() for memmap virtual address mapping
For the memmap buffer, instead of allocating an array of struct
pages, assigning them to the contiguous phsycial memory and then
passing that to vmap(), use vmap_page_range() instead
- Replace flush_dcache_folio() with flush_kernel_vmap_range()
Instead of calling virt_to_folio() and passing that to
flush_dcache_folio(), just call flush_kernel_vmap_range() directly.
This also fixes a bug where if a subbuffer was bigger than
PAGE_SIZE only the PAGE_SIZE portion would be flushed"
* tag 'trace-ringbuffer-v6.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Use flush_kernel_vmap_range() over flush_dcache_folio()
tracing: Use vmap_page_range() to map memmap ring buffer
tracing: Have reserve_mem use phys_to_virt() and separate from memmap buffer
tracing: Enforce the persistent ring buffer to be page aligned
- Fix build error when CONFIG_PROBE_EVENTS_BTF_ARGS is not enabled
The tracing of arguments in the function tracer depends on some
functions that are only defined when PROBE_EVENTS_BTF_ARGS is enabled.
In fact, PROBE_EVENTS_BTF_ARGS also depends on all the same configs
as the function argument tracing requires. Just have the function
argument tracing depend on PROBE_EVENTS_BTF_ARGS.
- Free module_delta for persistent ring buffer instance
When an instance holds the persistent ring buffer, it allocates
a helper array to hold the deltas between where modules are loaded
on the last boot and the current boot. This array needs to be freed
when the instance is freed.
- Add cond_resched() to loop in ftrace_graph_set_hash()
The hash functions in ftrace loop over every function that can be
enabled by ftrace. This can be 50,000 functions or more. This
loop is known to trigger soft lockup warnings and requires a
cond_resched(). The loop in ftrace_graph_set_hash() was missing it.
- Fix the event format verifier to include "%*p.." arguments
To prevent events from dereferencing stale pointers that can
happen if a trace event uses a dereferece pointer to something
that was not copied into the ring buffer and can be freed by the
time the trace is read, a verifier is called. At boot or module
load, the verifier scans the print format string for pointers
that can be dereferenced and it checks the arguments to make sure
they do not contain something that can be freed. The "%*p" was
not handled, which would add another argument and cause the verifier
to not only not verify this pointer, but it will look at the wrong
argument for every pointer after that.
- Fix mcount sorttable building for different endian type target
When modifying the ELF file to sort the mcount_loc table in the
sorttable.c code, the endianess of the file and the host is used
to determine if the bytes need to be swapped when calculations are
done. A change was made to the sorting of the mcount_loc that read
the values from the ELF file into an array and the swap happened
on the filling of the array. But one of the calculations of the
array still did the swap when it did not need to. This caused building
on a little endian machine for a big endian target to not find
the mcount function in the 'nm' table and it zeroed it out, causing
there to be no functions available to trace.
- Add goto out_unlock jump to rv_register_monitor() on error path
One of the error paths in rv_register_monitor() just returned the
error when it should have jumped to the out_unlock label to release
the mutex.
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Merge tag 'trace-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix build error when CONFIG_PROBE_EVENTS_BTF_ARGS is not enabled
The tracing of arguments in the function tracer depends on some
functions that are only defined when PROBE_EVENTS_BTF_ARGS is
enabled. In fact, PROBE_EVENTS_BTF_ARGS also depends on all the same
configs as the function argument tracing requires. Just have the
function argument tracing depend on PROBE_EVENTS_BTF_ARGS.
- Free module_delta for persistent ring buffer instance
When an instance holds the persistent ring buffer, it allocates a
helper array to hold the deltas between where modules are loaded on
the last boot and the current boot. This array needs to be freed when
the instance is freed.
- Add cond_resched() to loop in ftrace_graph_set_hash()
The hash functions in ftrace loop over every function that can be
enabled by ftrace. This can be 50,000 functions or more. This loop is
known to trigger soft lockup warnings and requires a cond_resched().
The loop in ftrace_graph_set_hash() was missing it.
- Fix the event format verifier to include "%*p.." arguments
To prevent events from dereferencing stale pointers that can happen
if a trace event uses a dereferece pointer to something that was not
copied into the ring buffer and can be freed by the time the trace is
read, a verifier is called. At boot or module load, the verifier
scans the print format string for pointers that can be dereferenced
and it checks the arguments to make sure they do not contain
something that can be freed. The "%*p" was not handled, which would
add another argument and cause the verifier to not only not verify
this pointer, but it will look at the wrong argument for every
pointer after that.
- Fix mcount sorttable building for different endian type target
When modifying the ELF file to sort the mcount_loc table in the
sorttable.c code, the endianess of the file and the host is used to
determine if the bytes need to be swapped when calculations are done.
A change was made to the sorting of the mcount_loc that read the
values from the ELF file into an array and the swap happened on the
filling of the array. But one of the calculations of the array still
did the swap when it did not need to. This caused building on a
little endian machine for a big endian target to not find the mcount
function in the 'nm' table and it zeroed it out, causing there to be
no functions available to trace.
- Add goto out_unlock jump to rv_register_monitor() on error path
One of the error paths in rv_register_monitor() just returned the
error when it should have jumped to the out_unlock label to release
the mutex.
* tag 'trace-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
rv: Fix missing unlock on double nested monitors return path
scripts/sorttable: Fix endianness handling in build-time mcount sort
tracing: Verify event formats that have "%*p.."
ftrace: Add cond_resched() to ftrace_graph_set_hash()
tracing: Free module_delta on freeing of persistent ring buffer
ftrace: Have tracing function args depend on PROBE_EVENTS_BTF_ARGS
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Merge tag 'printk-for-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull more printk updates from Petr Mladek:
- Silence warnings about candidates for ‘gnu_print’ format attribute
* tag 'printk-for-6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
vsnprintf: Silence false positive GCC warning for va_format()
vsnprintf: Drop unused const char fmt * in va_format()
vsnprintf: Mark binary printing functions with __printf() attribute
tracing: Mark binary printing functions with __printf() attribute
seq_file: Mark binary printing functions with __printf() attribute
seq_buf: Mark binary printing functions with __printf() attribute
Some architectures do not have data cache coherency between user and
kernel space. For these architectures, the cache needs to be flushed on
both the kernel and user addresses so that user space can see the updates
the kernel has made.
Instead of using flush_dcache_folio() and playing with virt_to_folio()
within the call to that function, use flush_kernel_vmap_range() which
takes the virtual address and does the work for those architectures that
need it.
This also fixes a bug where the flush of the reader page only flushed one
page. If the sub-buffer order is 1 or more, where the sub-buffer size
would be greater than a page, it would miss the rest of the sub-buffer
content, as the "reader page" is not just a page, but the size of a
sub-buffer.
Link: https://lore.kernel.org/all/CAG48ez3w0my4Rwttbc5tEbNsme6tc0mrSN95thjXUFaJ3aQ6SA@mail.gmail.com/
Cc: stable@vger.kernel.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@kernel.org>
Link: https://lore.kernel.org/20250402144953.920792197@goodmis.org
Fixes: 117c39200d ("ring-buffer: Introducing ring-buffer mapping functions");
Suggested-by: Jann Horn <jannh@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The code to map the physical memory retrieved by memmap currently
allocates an array of pages to cover the physical memory and then calls
vmap() to map it to a virtual address. Instead of using this temporary
array of struct page descriptors, simply use vmap_page_range() that can
directly map the contiguous physical memory to a virtual address.
Link: https://lore.kernel.org/all/CAHk-=whUOfVucfJRt7E0AH+GV41ELmS4wJqxHDnui6Giddfkzw@mail.gmail.com/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/20250402144953.754618481@goodmis.org
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The reserve_mem kernel command line option may pass back a physical
address, but the memory is still part of the normal memory just like
using memblock_alloc() would be. This means that the physical memory
returned by the reserve_mem command line option can be converted directly
to virtual memory by simply using phys_to_virt().
When freeing the buffer there's no need to call vunmap() anymore as the
memory allocated by reserve_mem is freed by the call to
reserve_mem_release_by_name().
Because the persistent ring buffer can also be allocated via the memmap
option, which *is* different than normal memory as it cannot be added back
to the buddy system, it must be treated differently. It still needs to be
virtually mapped to have access to it. It also can not be freed nor can it
ever be memory mapped to user space.
Create a new trace_array flag called TRACE_ARRAY_FL_MEMMAP which gets set
if the buffer is created by the memmap option, and this will prevent the
buffer from being memory mapped by user space.
Also increment the ref count for memmap'ed buffers so that they can never
be freed.
Link: https://lore.kernel.org/all/Z-wFszhJ_9o4dc8O@kernel.org/
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/20250402144953.583750106@goodmis.org
Suggested-by: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Enforce that the address and the size of the memory used by the persistent
ring buffer is page aligned. Also update the documentation to reflect this
requirement.
Link: https://lore.kernel.org/all/CAHk-=whUOfVucfJRt7E0AH+GV41ELmS4wJqxHDnui6Giddfkzw@mail.gmail.com/
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/20250402144953.412882844@goodmis.org
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Commit ac91052f0a ("tracing: tprobe-events: Fix leakage of module
refcount") moved try_module_get() from __find_tracepoint_module_cb()
to find_tracepoint() caller, but that introduced a possible UAF
because the module can be unloaded before try_module_get(). In this
case, the module object should be freed too. Thus, try_module_get()
does not only fail but may access to the freed object.
To avoid that, try_module_get() in __find_tracepoint_module_cb()
again.
Link: https://lore.kernel.org/all/174342990779.781946.9138388479067729366.stgit@devnote2/
Fixes: ac91052f0a ("tracing: tprobe-events: Fix leakage of module refcount")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
RV doesn't support nested monitors having children monitors themselves
and exits with the EINVAL code. However, it returns without unlocking
the rv_interface_lock.
Unlock the lock before returning from the initialisation function.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/20250402071351.19864-2-gmonaco@redhat.com
Fixes: cb85c660fc ("rv: Add option for nested monitors and include sched")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Closes: https://lore.kernel.org/r/202503310200.UBXGitB4-lkp@intel.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The trace event verifier checks the formats of trace events to make sure
that they do not point at memory that is not in the trace event itself or
in data that will never be freed. If an event references data that was
allocated when the event triggered and that same data is freed before the
event is read, then the kernel can crash by reading freed memory.
The verifier runs at boot up (or module load) and scans the print formats
of the events and checks their arguments to make sure that dereferenced
pointers are safe. If the format uses "%*p.." the verifier will ignore it,
and that could be dangerous. Cover this case as well.
Also add to the sample code a use case of "%*pbl".
Link: https://lore.kernel.org/all/bcba4d76-2c3f-4d11-baf0-02905db953dd@oracle.com/
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 5013f454a3 ("tracing: Add check of trace event print fmts for dereferencing pointers")
Link: https://lore.kernel.org/20250327195311.2d89ec66@gandalf.local.home
Reported-by: Libo Chen <libo.chen@oracle.com>
Reviewed-by: Libo Chen <libo.chen@oracle.com>
Tested-by: Libo Chen <libo.chen@oracle.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When the kernel contains a large number of functions that can be traced,
the loop in ftrace_graph_set_hash() may take a lot of time to execute.
This may trigger the softlockup watchdog.
Add cond_resched() within the loop to allow the kernel to remain
responsive even when processing a large number of functions.
This matches the cond_resched() that is used in other locations of the
code that iterates over all functions that can be traced.
Cc: stable@vger.kernel.org
Fixes: b9b0c831be ("ftrace: Convert graph filter to use hash tables")
Link: https://lore.kernel.org/tencent_3E06CE338692017B5809534B9C5C03DA7705@qq.com
Signed-off-by: zhoumin <teczm@foxmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
If a persistent ring buffer is created, a "module_delta" array is also
allocated to hold the module deltas of loaded modules that match modules
in the scratch area. If this buffer gets freed, the module_delta array is
not freed and causes a memory leak.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250401124525.1f9ac02a@gandalf.local.home
Fixes: 35a380ddbc ("tracing: Show last module text symbols in the stacktrace")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The option PROBE_EVENTS_BTF_ARGS enables the functions
btf_find_func_proto() and btf_get_func_param() which are used by the
function argument tracing code. The option FUNCTION_TRACE_ARGS was
dependent on the same configs that PROBE_EVENTS_BTF_ARGS was dependent on,
but it was also dependent on PROBE_EVENTS_BTF_ARGS. In fact, if
PROBE_EVENTS_BTF_ARGS is supported then FUNCTION_TRACE_ARGS is supported.
Just make FUNCTION_TRACE_ARGS depend on PROBE_EVENTS_BTF_ARGS.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/20250401113601.17fa1129@gandalf.local.home
Fixes: 533c20b062 ("ftrace: Add print_function_args()")
Closes: https://lore.kernel.org/all/DB9PR08MB75820599801BAD118D123D7D93AD2@DB9PR08MB7582.eurprd08.prod.outlook.com/
Reported-by: Christian Loehle <Christian.Loehle@arm.com>
Tested-by: Christian Loehle <Christian.Loehle@arm.com>
Tested-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Restructure the persistent memory to have a "scratch" area
Instead of hard coding the KASLR offset in the persistent memory
by the ring buffer, push that work up to the callers of the persistent
memory as they are the ones that need this information. The offsets
and such is not important to the ring buffer logic and it should
not be part of that.
A scratch pad is now created when the caller allocates a ring buffer
from persistent memory by stating how much memory it needs to save.
- Allow where modules are loaded to be saved in the new scratch pad
Save the addresses of modules when they are loaded into the persistent
memory scratch pad.
- A new module_for_each_mod() helper function was created
With the acknowledgement of the module maintainers a new module helper
function was created to iterate over all the currently loaded modules.
This has a callback to be called for each module. This is needed for
when tracing is started in the persistent buffer and the currently loaded
modules need to be saved in the scratch area.
- Expose the last boot information where the kernel and modules were loaded
The last_boot_info file is updated to print out the addresses of where
the kernel "_text" location was loaded from a previous boot, as well
as where the modules are loaded. If the buffer is recording the current
boot, it only prints "# Current" so that it does not expose the KASLR
offset of the currently running kernel.
- Allow the persistent ring buffer to be released (freed)
To have this in production environments, where the kernel command line can
not be changed easily, the ring buffer needs to be freed when it is not
going to be used. The memory for the buffer will always be allocated at
boot up, but if the system isn't going to enable tracing, the memory needs
to be freed. Allow it to be freed and added back to the kernel memory
pool.
- Allow stack traces to print the function names in the persistent buffer
Now that the modules are saved in the persistent ring buffer, if the same
modules are loaded, the printing of the function names will examine the
saved modules. If the module is found in the scratch area and is also
loaded, then it will do the offset shift and use kallsyms to display the
function name. If the address is not found, it simply displays the address
from the previous boot in hex.
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Merge tag 'trace-ringbuffer-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ring-buffer updates from Steven Rostedt:
- Restructure the persistent memory to have a "scratch" area
Instead of hard coding the KASLR offset in the persistent memory by
the ring buffer, push that work up to the callers of the persistent
memory as they are the ones that need this information. The offsets
and such is not important to the ring buffer logic and it should not
be part of that.
A scratch pad is now created when the caller allocates a ring buffer
from persistent memory by stating how much memory it needs to save.
- Allow where modules are loaded to be saved in the new scratch pad
Save the addresses of modules when they are loaded into the
persistent memory scratch pad.
- A new module_for_each_mod() helper function was created
With the acknowledgement of the module maintainers a new module
helper function was created to iterate over all the currently loaded
modules. This has a callback to be called for each module. This is
needed for when tracing is started in the persistent buffer and the
currently loaded modules need to be saved in the scratch area.
- Expose the last boot information where the kernel and modules were
loaded
The last_boot_info file is updated to print out the addresses of
where the kernel "_text" location was loaded from a previous boot, as
well as where the modules are loaded. If the buffer is recording the
current boot, it only prints "# Current" so that it does not expose
the KASLR offset of the currently running kernel.
- Allow the persistent ring buffer to be released (freed)
To have this in production environments, where the kernel command
line can not be changed easily, the ring buffer needs to be freed
when it is not going to be used. The memory for the buffer will
always be allocated at boot up, but if the system isn't going to
enable tracing, the memory needs to be freed. Allow it to be freed
and added back to the kernel memory pool.
- Allow stack traces to print the function names in the persistent
buffer
Now that the modules are saved in the persistent ring buffer, if the
same modules are loaded, the printing of the function names will
examine the saved modules. If the module is found in the scratch area
and is also loaded, then it will do the offset shift and use kallsyms
to display the function name. If the address is not found, it simply
displays the address from the previous boot in hex.
* tag 'trace-ringbuffer-v6.15-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Use _text and the kernel offset in last_boot_info
tracing: Show last module text symbols in the stacktrace
ring-buffer: Remove the unused variable bmeta
tracing: Skip update_last_data() if cleared and remove active check for save_mod()
tracing: Initialize scratch_size to zero to prevent UB
tracing: Fix a compilation error without CONFIG_MODULES
tracing: Freeable reserved ring buffer
mm/memblock: Add reserved memory release function
tracing: Update modules to persistent instances when loaded
tracing: Show module names and addresses of last boot
tracing: Have persistent trace instances save module addresses
module: Add module_for_each_mod() function
tracing: Have persistent trace instances save KASLR offset
ring-buffer: Add ring_buffer_meta_scratch()
ring-buffer: Add buffer meta data for persistent ring buffer
ring-buffer: Use kaslr address instead of text delta
ring-buffer: Fix bytes_dropped calculation issue
- Use RCU instead of RCU-sched
The mix of rcu_read_lock(), rcu_read_lock_sched() and preempt_disable()
in the module code and its users has been replaced with just
rcu_read_lock().
- The rest of changes are smaller fixes and updates.
The changes have been on linux-next for at least 2 weeks, with the RCU
cleanup present for 2 months. One performance problem was reported with the
RCU change when KASAN + lockdep were enabled, but it was effectively
addressed by the already merged ee57ab5a32 ("locking/lockdep: Disable
KASAN instrumentation of lockdep.c").
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Merge tag 'modules-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux
Pull modules updates from Petr Pavlu:
- Use RCU instead of RCU-sched
The mix of rcu_read_lock(), rcu_read_lock_sched() and
preempt_disable() in the module code and its users has
been replaced with just rcu_read_lock()
- The rest of changes are smaller fixes and updates
* tag 'modules-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux: (32 commits)
MAINTAINERS: Update the MODULE SUPPORT section
module: Remove unnecessary size argument when calling strscpy()
module: Replace deprecated strncpy() with strscpy()
params: Annotate struct module_param_attrs with __counted_by()
bug: Use RCU instead RCU-sched to protect module_bug_list.
static_call: Use RCU in all users of __module_text_address().
kprobes: Use RCU in all users of __module_text_address().
bpf: Use RCU in all users of __module_text_address().
jump_label: Use RCU in all users of __module_text_address().
jump_label: Use RCU in all users of __module_address().
x86: Use RCU in all users of __module_address().
cfi: Use RCU while invoking __module_address().
powerpc/ftrace: Use RCU in all users of __module_text_address().
LoongArch: ftrace: Use RCU in all users of __module_text_address().
LoongArch/orc: Use RCU in all users of __module_address().
arm64: module: Use RCU in all users of __module_text_address().
ARM: module: Use RCU in all users of __module_text_address().
module: Use RCU in all users of __module_text_address().
module: Use RCU in all users of __module_address().
module: Use RCU in search_module_extables().
...
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Merge tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
"For this merge window we're splitting BPF pull request into three for
higher visibility: main changes, res_spin_lock, try_alloc_pages.
These are the main BPF changes:
- Add DFA-based live registers analysis to improve verification of
programs with loops (Eduard Zingerman)
- Introduce load_acquire and store_release BPF instructions and add
x86, arm64 JIT support (Peilin Ye)
- Fix loop detection logic in the verifier (Eduard Zingerman)
- Drop unnecesary lock in bpf_map_inc_not_zero() (Eric Dumazet)
- Add kfunc for populating cpumask bits (Emil Tsalapatis)
- Convert various shell based tests to selftests/bpf/test_progs
format (Bastien Curutchet)
- Allow passing referenced kptrs into struct_ops callbacks (Amery
Hung)
- Add a flag to LSM bpf hook to facilitate bpf program signing
(Blaise Boscaccy)
- Track arena arguments in kfuncs (Ihor Solodrai)
- Add copy_remote_vm_str() helper for reading strings from remote VM
and bpf_copy_from_user_task_str() kfunc (Jordan Rome)
- Add support for timed may_goto instruction (Kumar Kartikeya
Dwivedi)
- Allow bpf_get_netns_cookie() int cgroup_skb programs (Mahe Tardy)
- Reduce bpf_cgrp_storage_busy false positives when accessing cgroup
local storage (Martin KaFai Lau)
- Introduce bpf_dynptr_copy() kfunc (Mykyta Yatsenko)
- Allow retrieving BTF data with BTF token (Mykyta Yatsenko)
- Add BPF kfuncs to set and get xattrs with 'security.bpf.' prefix
(Song Liu)
- Reject attaching programs to noreturn functions (Yafang Shao)
- Introduce pre-order traversal of cgroup bpf programs (Yonghong
Song)"
* tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (186 commits)
selftests/bpf: Add selftests for load-acquire/store-release when register number is invalid
bpf: Fix out-of-bounds read in check_atomic_load/store()
libbpf: Add namespace for errstr making it libbpf_errstr
bpf: Add struct_ops context information to struct bpf_prog_aux
selftests/bpf: Sanitize pointer prior fclose()
selftests/bpf: Migrate test_xdp_vlan.sh into test_progs
selftests/bpf: test_xdp_vlan: Rename BPF sections
bpf: clarify a misleading verifier error message
selftests/bpf: Add selftest for attaching fexit to __noreturn functions
bpf: Reject attaching fexit/fmod_ret to __noreturn functions
bpf: Only fails the busy counter check in bpf_cgrp_storage_get if it creates storage
bpf: Make perf_event_read_output accessible in all program types.
bpftool: Using the right format specifiers
bpftool: Add -Wformat-signedness flag to detect format errors
selftests/bpf: Test freplace from user namespace
libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID
bpf: Return prog btf_id without capable check
bpf: BPF token support for BPF_BTF_GET_FD_BY_ID
bpf, x86: Fix objtool warning for timed may_goto
bpf: Check map->record at the beginning of check_and_free_fields()
...
Instead of using kaslr_offset() just record the location of "_text". This
makes it possible for user space to use either the System.map or
/proc/kallsyms as what to map all addresses to functions with.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250326220304.38dbedcd@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Since the previous boot trace buffer can include module text address in
the stacktrace. As same as the kernel text address, convert the module
text address using the module address information.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/174282689201.356346.17647540360450727687.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
If the last boot data is already cleared, there is no reason to update it
again. Skip if the TRACE_ARRAY_FL_LAST_BOOT is cleared.
Also, for calling save_mod() when module loading, we don't need to check
the trace is active or not because any module address can be on the
stacktrace.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/174165660328.1173316.15529357882704817499.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
In allocate_trace_buffer() the following code:
buf->buffer = ring_buffer_alloc_range(size, rb_flags, 0,
tr->range_addr_start,
tr->range_addr_size,
struct_size(tscratch, entries, 128));
tscratch = ring_buffer_meta_scratch(buf->buffer, &scratch_size);
setup_trace_scratch(tr, tscratch, scratch_size);
Has undefined behavior if ring_buffer_alloc_range() fails because
"scratch_size" is not initialize. If the allocation fails, then
buf->buffer will be NULL. The ring_buffer_meta_scratch() will return
NULL immediately if it is passed a NULL buffer and it will not update
scratch_size. Then setup_trace_scratch() will return immediately if
tscratch is NULL.
Although there's no real issue here, but it is considered undefined
behavior to pass an uninitialized variable to a function as input, and
UBSan may complain about it.
Just initialize scratch_size to zero to make the code defined behavior and
a little more robust.
Link: https://lore.kernel.org/all/44c5deaa-b094-4852-90f9-52f3fb10e67a@stanley.mountain/
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
There are some code which depends on CONFIG_MODULES. #ifdef
to enclose it.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/174230515367.2909896.8132122175220657625.stgit@mhiramat.tok.corp.google.com
Fixes: dca91c1c5468 ("tracing: Have persistent trace instances save module addresses")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Make the ring buffer on reserved memory to be freeable. This allows us
to free the trace instance on the reserved memory without changing
cmdline and rebooting. Even if we can not change the kernel cmdline
for security reason, we can release the reserved memory for the ring
buffer as free (available) memory.
For example, boot kernel with reserved memory;
"reserve_mem=20M:2M:trace trace_instance=boot_mapped^traceoff@trace"
~ # free
total used free shared buff/cache available
Mem: 1995548 50544 1927568 14964 17436 1911480
Swap: 0 0 0
~ # rmdir /sys/kernel/tracing/instances/boot_mapped/
[ 23.704023] Freeing reserve_mem:trace memory: 20476K
~ # free
total used free shared buff/cache available
Mem: 2016024 41844 1956740 14968 17440 1940572
Swap: 0 0 0
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Link: https://lore.kernel.org/173989134814.230693.18199312930337815629.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When a module is loaded and a persistent buffer is actively tracing, add
it to the list of modules in the persistent memory.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250305164609.469844721@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add the last boot module's names and addresses to the last_boot_info file.
This only shows the module information from a previous boot. If the buffer
is started and is recording the current boot, this file still will only
show "current".
~# cat instances/boot_mapped/last_boot_info
10c00000 [kernel]
ffffffffc00ca000 usb_serial_simple
ffffffffc00ae000 usbserial
ffffffffc008b000 bfq
~# echo function > instances/boot_mapped/current_tracer
~# cat instances/boot_mapped/last_boot_info
# Current
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250305164609.299186021@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
For trace instances that are mapped to persistent memory, have them use
the scratch area to save the currently loaded modules. This will allow
where the modules have been loaded on the next boot so that their
addresses can be deciphered by using where they were loaded previously.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250305164609.129741650@goodmis.org
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
There's no reason to save the KASLR offset for the ring buffer itself.
That is used by the tracer. Now that the tracer has a way to save data in
the persistent memory of the ring buffer, have the tracing infrastructure
take care of the saving of the KASLR offset.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250305164608.792722274@goodmis.org
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Now that there's one meta data at the start of the persistent memory used by
the ring buffer, allow the caller to request some memory right after that
data that it can use as its own persistent memory.
Also fix some white space issues with ring_buffer_alloc().
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250305164608.619631731@goodmis.org
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Instead of just having a meta data at the first page of each sub buffer
that has duplicate data, add a new meta page to the entire block of memory
that holds the duplicate data and remove it from the sub buffer meta data.
This will open up the extra memory in this first page to be used by the
tracer for its own persistent data.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250305164608.446351513@goodmis.org
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Instead of saving off the text and data pointers and using them to compare
with the current boot's text and data pointers, just save off the KASLR
offset. Then that can be used to figure out how to read the previous boots
buffer.
The last_boot_info will now show this offset, but only if it is for a
previous boot:
~# cat instances/boot_mapped/last_boot_info
39000000 [kernel]
~# echo function > instances/boot_mapped/current_tracer
~# cat instances/boot_mapped/last_boot_info
# Current
If the KASLR offset saved is for the current boot, the last_boot_info will
show the value of "current".
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250305164608.274956504@goodmis.org
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The calculation of bytes-dropped and bytes_dropped_nested is reversed.
Although it does not affect the final calculation of total_dropped,
it should still be modified.
Link: https://lore.kernel.org/20250223070106.6781-1-yangfeng59949@163.com
Fixes: 6c43e554a2 ("ring-buffer: Add ring buffer startup selftest")
Signed-off-by: Feng Yang <yangfeng@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Binary printing functions are using printf() type of format, and compiler
is not happy about them as is:
kernel/trace/trace.c:3292:9: error: function ‘trace_vbprintk’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format]
kernel/trace/trace_seq.c:182:9: error: function ‘trace_seq_bprintf’ might be a candidate for ‘gnu_printf’ format attribute [-Werror=suggest-attribute=format]
Fix the compilation errors by adding __printf() attribute.
While at it, move existing __printf() attributes from the implementations
to the declarations. IT also fixes incorrect attribute parameters that are
used for trace_array_printk().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20250321144822.324050-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
- probe-events: Add comments about entry data storing code to clarify
where and how the entry data is stored for function return events.
- probe-events: Log error for exceeding the number of arguments to help
user to identify error reason via tracefs/error_log file.
- selftests/ftrace: Improve the ftracetest to add followngs.
. Expand the tprobe event test to check if it can correctly find
the wrong format tracepoint name.
. Add new syntax error test to check whether error_log correctly
indicates a wrong character in the tracepoint name.
. Add a new dynamic events argument limitation test case which checks
max number of probe arguments.
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Merge tag 'probes-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes updates from Masami Hiramatsu:
- probe-events: Add comments about entry data storing code to clarify
where and how the entry data is stored for function return events.
- probe-events: Log error for exceeding the number of arguments to help
user to identify error reason via tracefs/error_log file.
- Improve the ftracetest selftests:
- Expand the tprobe event test to check if it can correctly find the
wrong format tracepoint name.
- Add new syntax error test to check whether error_log correctly
indicates a wrong character in the tracepoint name.
- Add a new dynamic events argument limitation test case which
checks max number of probe arguments.
* tag 'probes-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: probe-events: Add comments about entry data storing code
selftests/ftrace: Add dynamic events argument limitation test case
selftests/ftrace: Add new syntax error test
selftests/ftrace: Expand the tprobe event test to check wrong format
tracing: probe-events: Log error for exceeding the number of arguments
- Add option traceoff_after_boot
In order to debug kernel boot, it sometimes is helpful to enable tracing
via the kernel command line. Unfortunately, by the time the login prompt
appears, the trace is overwritten by the init process and other user space
start up applications. Adding a "traceoff_after_boot" will disable tracing
when the kernel passes control to init which will allow developers to be
able to see the traces that occurred during boot.
- Clean up the mmflags macros that display the GFP flags in trace events
The macros to print the GFP flags for trace events had a bit of
duplication. The code was restructured to remove duplication and in the
process it also adds some flags that were missed before.
- Removed some dead code and scripts/draw_functrace.py
draw_functrace.py hasn't worked in years and as nobody complained
about it, remove it.
- Constify struct event_trigger_ops
The event_trigger_ops is just a structure that has function pointers that
are assigned when the variables are created. These variables should all be
constants.
- Other minor clean ups and fixes
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Merge tag 'trace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Add option traceoff_after_boot
In order to debug kernel boot, it sometimes is helpful to enable
tracing via the kernel command line. Unfortunately, by the time the
login prompt appears, the trace is overwritten by the init process
and other user space start up applications.
Adding a "traceoff_after_boot" will disable tracing when the kernel
passes control to init which will allow developers to be able to see
the traces that occurred during boot.
- Clean up the mmflags macros that display the GFP flags in trace
events
The macros to print the GFP flags for trace events had a bit of
duplication. The code was restructured to remove duplication and in
the process it also adds some flags that were missed before.
- Removed some dead code and scripts/draw_functrace.py
draw_functrace.py hasn't worked in years and as nobody complained
about it, remove it.
- Constify struct event_trigger_ops
The event_trigger_ops is just a structure that has function pointers
that are assigned when the variables are created. These variables
should all be constants.
- Other minor clean ups and fixes
* tag 'trace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Replace strncpy with memcpy for fixed-length substring copy
tracing: Fix synth event printk format for str fields
tracing: Do not use PERF enums when perf is not defined
tracing: Ensure module defining synth event cannot be unloaded while tracing
tracing: fix return value in __ftrace_event_enable_disable for TRACE_REG_UNREGISTER
tracing/osnoise: Fix possible recursive locking for cpus_read_lock()
tracing: Align synth event print fmt
tracing: gfp: vsprintf: Do not print "none" when using %pGg printf format
tracepoint: Print the function symbol when tracepoint_debug is set
tracing: Constify struct event_trigger_ops
scripts/tracing: Remove scripts/tracing/draw_functrace.py
tracing: Update MAINTAINERS file to include tracepoint.c
tracing/user_events: Slightly simplify user_seq_show()
tracing/user_events: Don't use %pK through printk
tracing: gfp: Remove duplication of recording GFP flags
tracing: Remove orphaned event_trace_printk
ring-buffer: Fix typo in comment about header page pointer
tracing: Add traceoff_after_boot option
- Add some trace events to osnoise and timerlat sample generation
This adds more information to the osnoise and timerlat tracers as well as
allows BPF programs to be attached to these locations to extract even more
data.
- Fix to DECLARE_TRACE_CONDITION() macro
It wasn't used but now will be and it happened to be broken causing the
build to fail.
- Add scheduler specification monitors to runtime verifier (RV)
This is a continuation of Daniel Bristot's work.
RV allows monitors to run and react concurrently. Running the cumulative
model is equivalent to running single components using the same
reactors, with the advantage that it's easier to point out which
specification failed in case of error.
This update introduces nested monitors to RV, in short, the sysfs
monitor folder will contain a monitor named sched, which is nothing but
an empty container for other monitors. Controlling the sched monitor
(enable, disable, set reactors) controls all nested monitors.
The following scheduling monitors are added:
* sco: scheduling context operations
Monitor to ensure sched_set_state happens only in thread context
* tss: task switch while scheduling
Monitor to ensure sched_switch happens only in scheduling context
* snroc: set non runnable on its own context
Monitor to ensure set_state happens only in the respective task's context
* scpd: schedule called with preemption disabled
Monitor to ensure schedule is called with preemption disabled
* snep: schedule does not enable preempt
Monitor to ensure schedule does not enable preempt
* sncid: schedule not called with interrupt disabled
Monitor to ensure schedule is not called with interrupt disabled
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Merge tag 'trace-latency-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull latency tracing updates from Steven Rostedt:
- Add some trace events to osnoise and timerlat sample generation
This adds more information to the osnoise and timerlat tracers as
well as allows BPF programs to be attached to these locations to
extract even more data.
- Fix to DECLARE_TRACE_CONDITION() macro
It wasn't used but now will be and it happened to be broken causing
the build to fail.
- Add scheduler specification monitors to runtime verifier (RV)
This is a continuation of Daniel Bristot's work.
RV allows monitors to run and react concurrently. Running the
cumulative model is equivalent to running single components using the
same reactors, with the advantage that it's easier to point out which
specification failed in case of error.
This update introduces nested monitors to RV, in short, the sysfs
monitor folder will contain a monitor named sched, which is nothing
but an empty container for other monitors. Controlling the sched
monitor (enable, disable, set reactors) controls all nested monitors.
The following scheduling monitors are added:
- sco: scheduling context operations
Monitor to ensure sched_set_state happens only in thread context
- tss: task switch while scheduling
Monitor to ensure sched_switch happens only in scheduling context
- snroc: set non runnable on its own context
Monitor to ensure set_state happens only in the respective task's context
- scpd: schedule called with preemption disabled
Monitor to ensure schedule is called with preemption disabled
- snep: schedule does not enable preempt
Monitor to ensure schedule does not enable preempt
- sncid: schedule not called with interrupt disabled
Monitor to ensure schedule is not called with interrupt disabled
* tag 'trace-latency-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tools/rv: Allow rv list to filter for container
Documentation/rv: Add docs for the sched monitors
verification/dot2k: Add support for nested monitors
tools/rv: Add support for nested monitors
rv: Add scpd, snep and sncid per-cpu monitors
rv: Add snroc per-task monitor
rv: Add sco and tss per-cpu monitors
rv: Add option for nested monitors and include sched
sched: Add sched tracepoints for RV task model
rv: Add license identifiers to monitor files
tracing: Fix DECLARE_TRACE_CONDITION
trace/osnoise: Add trace events for samples
- Record function parameters for function and function graph tracers
An option has been added to function tracer (func-args) and the function
graph tracer (funcgraph-args) that when set, the tracers will record the
registers that hold the arguments into each function event. On reading of
the trace, it will use BTF to print those arguments. Most archs support up
to 6 arguments (depending on the complexity of the arguments) and those
are printed. If a function has more arguments then what was recorded, the
output will end with " ... )".
Example of function graph tracer:
6) | dummy_xmit [dummy](skb = 0x8887c100, dev = 0x872ca000) {
6) | consume_skb(skb = 0x8887c100) {
6) | skb_release_head_state(skb = 0x8887c100) {
6) 0.178 us | sock_wfree(skb = 0x8887c100)
6) 0.627 us | }
- The rest of the changes are minor clean ups and fixes
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Merge tag 'ftrace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace updates from Steven Rostedt:
- Record function parameters for function and function graph tracers
An option has been added to function tracer (func-args) and the
function graph tracer (funcgraph-args) that when set, the tracers
will record the registers that hold the arguments into each function
event. On reading of the trace, it will use BTF to print those
arguments. Most archs support up to 6 arguments (depending on the
complexity of the arguments) and those are printed.
If a function has more arguments then what was recorded, the output
will end with " ... )".
Example of function graph tracer:
6) | dummy_xmit [dummy](skb = 0x8887c100, dev = 0x872ca000) {
6) | consume_skb(skb = 0x8887c100) {
6) | skb_release_head_state(skb = 0x8887c100) {
6) 0.178 us | sock_wfree(skb = 0x8887c100)
6) 0.627 us | }
- The rest of the changes are minor clean ups and fixes
* tag 'ftrace-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Use hashtable.h for event_hash
tracing: Fix use-after-free in print_graph_function_flags during tracer switching
function_graph: Remove the unused variable func
ftrace: Add arguments to function tracer
ftrace: Have funcgraph-args take affect during tracing
ftrace: Add support for function argument to graph tracer
ftrace: Add print_function_args()
ftrace: Have ftrace_free_filter() WARN and exit if ops is active
fgraph: Correct typo in ftrace_return_to_handler comment
- Implement arm64 build time sorting of the mcount location table
When gcc is used to build arm64, the mcount_loc section is all zeros in
the vmlinux elf file. The addresses are stored in the Elf_Rela location.
To sort at build time, an array is allocated and the addresses are added
to it via the content of the mcount_loc section as well as he Elf_Rela
data. After sorting, the information is put back into the Elf_Rela which
now has the section sorted.
- Make sorting of mcount location table for arm64 work with clang as well
When clang is used, the mcount_loc section contains the addresses, unlike
the gcc build. An array is still created and the sorting works for both
methods.
- Remove weak functions from the mcount_loc section
Have the sorttable code pass in the data of functions defined via nm -S
which shows the functions as well as their sizes. Using this information
the sorttable code can determine if a function in the mcount_loc section
was weak and overridden. If the function is not found, it is set to be
zero. On boot, when the mcount_loc section is read and the ftrace table is
created, if the address in the mcount_loc is not in the kernel core text
then it is removed and not added to the ftrace_filter_functions (the
functions that can be attached by ftrace callbacks).
- Update and fix the reporting of how much data is used for ftrace functions
On boot, a report of how many pages were used by the ftrace table as well
as how they were grouped (the table holds a list of sections that are
groups of pages that were able to be allocated). The removing of the weak
functions required the accounting to be updated.
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Merge tag 'trace-sorttable-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing / sorttable updates from Steven Rostedt:
- Implement arm64 build time sorting of the mcount location table
When gcc is used to build arm64, the mcount_loc section is all zeros
in the vmlinux elf file. The addresses are stored in the Elf_Rela
location.
To sort at build time, an array is allocated and the addresses are
added to it via the content of the mcount_loc section as well as he
Elf_Rela data. After sorting, the information is put back into the
Elf_Rela which now has the section sorted.
- Make sorting of mcount location table for arm64 work with clang as
well
When clang is used, the mcount_loc section contains the addresses,
unlike the gcc build. An array is still created and the sorting works
for both methods.
- Remove weak functions from the mcount_loc section
Have the sorttable code pass in the data of functions defined via
'nm -S' which shows the functions as well as their sizes. Using this
information the sorttable code can determine if a function in the
mcount_loc section was weak and overridden. If the function is not
found, it is set to be zero. On boot, when the mcount_loc section is
read and the ftrace table is created, if the address in the
mcount_loc is not in the kernel core text then it is removed and not
added to the ftrace_filter_functions (the functions that can be
attached by ftrace callbacks).
- Update and fix the reporting of how much data is used for ftrace
functions
On boot, a report of how many pages were used by the ftrace table as
well as how they were grouped (the table holds a list of sections
that are groups of pages that were able to be allocated). The
removing of the weak functions required the accounting to be updated.
* tag 'trace-sorttable-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
scripts/sorttable: Allow matches to functions before function entry
scripts/sorttable: Use normal sort if theres no relocs in the mcount section
ftrace: Check against is_kernel_text() instead of kaslr_offset()
ftrace: Test mcount_loc addr before calling ftrace_call_addr()
ftrace: Have ftrace pages output reflect freed pages
ftrace: Update the mcount_loc check of skipped entries
scripts/sorttable: Zero out weak functions in mcount_loc table
scripts/sorttable: Always use an array for the mcount_loc sorting
scripts/sorttable: Have mcount rela sort use direct values
arm64: scripts/sorttable: Implement sorting mcount_loc at boot for arm64
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Merge tag 'lsm-pr-20250323' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm
Pull lsm updates from Paul Moore:
- Various minor updates to the LSM Rust bindings
Changes include marking trivial Rust bindings as inlines and comment
tweaks to better reflect the LSM hooks.
- Add LSM/SELinux access controls to io_uring_allowed()
Similar to the io_uring_disabled sysctl, add a LSM hook to
io_uring_allowed() to enable LSMs a simple way to enforce security
policy on the use of io_uring. This pull request includes SELinux
support for this new control using the io_uring/allowed permission.
- Remove an unused parameter from the security_perf_event_open() hook
The perf_event_attr struct parameter was not used by any currently
supported LSMs, remove it from the hook.
- Add an explicit MAINTAINERS entry for the credentials code
We've seen problems in the past where patches to the credentials code
sent by non-maintainers would often languish on the lists for
multiple months as there was no one explicitly tasked with the
responsibility of reviewing and/or merging credentials related code.
Considering that most of the code under security/ has a vested
interest in ensuring that the credentials code is well maintained,
I'm volunteering to look after the credentials code and Serge Hallyn
has also volunteered to step up as an official reviewer. I posted the
MAINTAINERS update as a RFC to LKML in hopes that someone else would
jump up with an "I'll do it!", but beyond Serge it was all crickets.
- Update Stephen Smalley's old email address to prevent confusion
This includes a corresponding update to the mailmap file.
* tag 'lsm-pr-20250323' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
mailmap: map Stephen Smalley's old email addresses
lsm: remove old email address for Stephen Smalley
MAINTAINERS: add Serge Hallyn as a credentials reviewer
MAINTAINERS: add an explicit credentials entry
cred,rust: mark Credential methods inline
lsm,rust: reword "destroy" -> "release" in SecurityCtx
lsm,rust: mark SecurityCtx methods inline
perf: Remove unnecessary parameter of security check
lsm: fix a missing security_uring_allowed() prototype
io_uring,lsm,selinux: add LSM hooks for io_uring_setup()
io_uring: refactor io_uring_allowed()
checkpatch.pl reports the following warning:
WARNING: Prefer strscpy, strscpy_pad, or __nonstring over strncpy
(see: https://github.com/KSPP/linux/issues/90)
In synth_field_string_size(), replace strncpy() with memcpy() to copy 'len'
characters from 'start' to 'buf'. The code manually adds a NUL terminator
after the copy, making memcpy safe here.
Link: https://lore.kernel.org/20250325181232.38284-1-siddarthsgml@gmail.com
Signed-off-by: Siddarth G <siddarthsgml@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The printk format for synth event uses "%.*s" to print string fields,
but then only passes the pointer part as var arg.
Replace %.*s with %s as the C string is guaranteed to be null-terminated.
The output in print fmt should never have been updated as __get_str()
handles the string limit because it can access the length of the string in
the string meta data that is saved in the ring buffer.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 8db4d6bfbb ("tracing: Change synthetic event string format to limit printed length")
Link: https://lore.kernel.org/20250325165202.541088-1-douglas.raillard@arm.com
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
hrtimers are initialized with hrtimer_init() and a subsequent store to
the callback pointer. This turned out to be suboptimal for the upcoming
Rust integration and is obviously a silly implementation to begin with.
This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
with hrtimer_setup(T, cb);
The conversion was done with Coccinelle and a few manual fixups.
Once the conversion has completely landed in mainline, hrtimer_init()
will be removed and the hrtimer::function becomes a private member.
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Merge tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer cleanups from Thomas Gleixner:
"A treewide hrtimer timer cleanup
hrtimers are initialized with hrtimer_init() and a subsequent store to
the callback pointer. This turned out to be suboptimal for the
upcoming Rust integration and is obviously a silly implementation to
begin with.
This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
with hrtimer_setup(T, cb);
The conversion was done with Coccinelle and a few manual fixups.
Once the conversion has completely landed in mainline, hrtimer_init()
will be removed and the hrtimer::function becomes a private member"
* tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
wifi: rt2x00: Switch to use hrtimer_update_function()
io_uring: Use helper function hrtimer_update_function()
serial: xilinx_uartps: Use helper function hrtimer_update_function()
ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup()
RDMA: Switch to use hrtimer_setup()
virtio: mem: Switch to use hrtimer_setup()
drm/vmwgfx: Switch to use hrtimer_setup()
drm/xe/oa: Switch to use hrtimer_setup()
drm/vkms: Switch to use hrtimer_setup()
drm/msm: Switch to use hrtimer_setup()
drm/i915/request: Switch to use hrtimer_setup()
drm/i915/uncore: Switch to use hrtimer_setup()
drm/i915/pmu: Switch to use hrtimer_setup()
drm/i915/perf: Switch to use hrtimer_setup()
drm/i915/gvt: Switch to use hrtimer_setup()
drm/i915/huc: Switch to use hrtimer_setup()
drm/amdgpu: Switch to use hrtimer_setup()
stm class: heartbeat: Switch to use hrtimer_setup()
i2c: Switch to use hrtimer_setup()
iio: Switch to use hrtimer_setup()
...
two locking commits in the locking tree,
part of the locking-core-2025-03-22 pull request. ]
x86 CPU features support:
- Generate the <asm/cpufeaturemasks.h> header based on build config
(H. Peter Anvin, Xin Li)
- x86 CPUID parsing updates and fixes (Ahmed S. Darwish)
- Introduce the 'setcpuid=' boot parameter (Brendan Jackman)
- Enable modifying CPU bug flags with '{clear,set}puid='
(Brendan Jackman)
- Utilize CPU-type for CPU matching (Pawan Gupta)
- Warn about unmet CPU feature dependencies (Sohil Mehta)
- Prepare for new Intel Family numbers (Sohil Mehta)
Percpu code:
- Standardize & reorganize the x86 percpu layout and
related cleanups (Brian Gerst)
- Convert the stackprotector canary to a regular percpu
variable (Brian Gerst)
- Add a percpu subsection for cache hot data (Brian Gerst)
- Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak)
- Construct __percpu_seg_override from __percpu_seg (Uros Bizjak)
MM:
- Add support for broadcast TLB invalidation using AMD's INVLPGB instruction
(Rik van Riel)
- Rework ROX cache to avoid writable copy (Mike Rapoport)
- PAT: restore large ROX pages after fragmentation
(Kirill A. Shutemov, Mike Rapoport)
- Make memremap(MEMREMAP_WB) map memory as encrypted by default
(Kirill A. Shutemov)
- Robustify page table initialization (Kirill A. Shutemov)
- Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn)
- Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW
(Matthew Wilcox)
KASLR:
- x86/kaslr: Reduce KASLR entropy on most x86 systems,
to support PCI BAR space beyond the 10TiB region
(CONFIG_PCI_P2PDMA=y) (Balbir Singh)
CPU bugs:
- Implement FineIBT-BHI mitigation (Peter Zijlstra)
- speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta)
- speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan Gupta)
- RFDS: Exclude P-only parts from the RFDS affected list (Pawan Gupta)
System calls:
- Break up entry/common.c (Brian Gerst)
- Move sysctls into arch/x86 (Joel Granados)
Intel LAM support updates: (Maciej Wieczor-Retman)
- selftests/lam: Move cpu_has_la57() to use cpuinfo flag
- selftests/lam: Skip test if LAM is disabled
- selftests/lam: Test get_user() LAM pointer handling
AMD SMN access updates:
- Add SMN offsets to exclusive region access (Mario Limonciello)
- Add support for debugfs access to SMN registers (Mario Limonciello)
- Have HSMP use SMN through AMD_NODE (Yazen Ghannam)
Power management updates: (Patryk Wlazlyn)
- Allow calling mwait_play_dead with an arbitrary hint
- ACPI/processor_idle: Add FFH state handling
- intel_idle: Provide the default enter_dead() handler
- Eliminate mwait_play_dead_cpuid_hint()
Bootup:
Build system:
- Raise the minimum GCC version to 8.1 (Brian Gerst)
- Raise the minimum LLVM version to 15.0.0
(Nathan Chancellor)
Kconfig: (Arnd Bergmann)
- Add cmpxchg8b support back to Geode CPUs
- Drop 32-bit "bigsmp" machine support
- Rework CONFIG_GENERIC_CPU compiler flags
- Drop configuration options for early 64-bit CPUs
- Remove CONFIG_HIGHMEM64G support
- Drop CONFIG_SWIOTLB for PAE
- Drop support for CONFIG_HIGHPTE
- Document CONFIG_X86_INTEL_MID as 64-bit-only
- Remove old STA2x11 support
- Only allow CONFIG_EISA for 32-bit
Headers:
- Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI headers
(Thomas Huth)
Assembly code & machine code patching:
- x86/alternatives: Simplify alternative_call() interface (Josh Poimboeuf)
- x86/alternatives: Simplify callthunk patching (Peter Zijlstra)
- KVM: VMX: Use named operands in inline asm (Josh Poimboeuf)
- x86/hyperv: Use named operands in inline asm (Josh Poimboeuf)
- x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra)
- x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h>
(Uros Bizjak)
- Use named operands in inline asm (Uros Bizjak)
- Improve performance by using asm_inline() for atomic locking instructions
(Uros Bizjak)
Earlyprintk:
- Harden early_serial (Peter Zijlstra)
NMI handler:
- Add an emergency handler in nmi_desc & use it in nmi_shootdown_cpus()
(Waiman Long)
Miscellaneous fixes and cleanups:
- by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel,
Artem Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst,
Dan Carpenter, Dr. David Alan Gilbert, H. Peter Anvin,
Ingo Molnar, Josh Poimboeuf, Kevin Brodsky, Mike Rapoport,
Lukas Bulwahn, Maciej Wieczor-Retman, Max Grobecker,
Patryk Wlazlyn, Pawan Gupta, Peter Zijlstra,
Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner,
Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak,
Vitaly Kuznetsov, Xin Li, liuye.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core x86 updates from Ingo Molnar:
"x86 CPU features support:
- Generate the <asm/cpufeaturemasks.h> header based on build config
(H. Peter Anvin, Xin Li)
- x86 CPUID parsing updates and fixes (Ahmed S. Darwish)
- Introduce the 'setcpuid=' boot parameter (Brendan Jackman)
- Enable modifying CPU bug flags with '{clear,set}puid=' (Brendan
Jackman)
- Utilize CPU-type for CPU matching (Pawan Gupta)
- Warn about unmet CPU feature dependencies (Sohil Mehta)
- Prepare for new Intel Family numbers (Sohil Mehta)
Percpu code:
- Standardize & reorganize the x86 percpu layout and related cleanups
(Brian Gerst)
- Convert the stackprotector canary to a regular percpu variable
(Brian Gerst)
- Add a percpu subsection for cache hot data (Brian Gerst)
- Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak)
- Construct __percpu_seg_override from __percpu_seg (Uros Bizjak)
MM:
- Add support for broadcast TLB invalidation using AMD's INVLPGB
instruction (Rik van Riel)
- Rework ROX cache to avoid writable copy (Mike Rapoport)
- PAT: restore large ROX pages after fragmentation (Kirill A.
Shutemov, Mike Rapoport)
- Make memremap(MEMREMAP_WB) map memory as encrypted by default
(Kirill A. Shutemov)
- Robustify page table initialization (Kirill A. Shutemov)
- Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn)
- Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW
(Matthew Wilcox)
KASLR:
- x86/kaslr: Reduce KASLR entropy on most x86 systems, to support PCI
BAR space beyond the 10TiB region (CONFIG_PCI_P2PDMA=y) (Balbir
Singh)
CPU bugs:
- Implement FineIBT-BHI mitigation (Peter Zijlstra)
- speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta)
- speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan
Gupta)
- RFDS: Exclude P-only parts from the RFDS affected list (Pawan
Gupta)
System calls:
- Break up entry/common.c (Brian Gerst)
- Move sysctls into arch/x86 (Joel Granados)
Intel LAM support updates: (Maciej Wieczor-Retman)
- selftests/lam: Move cpu_has_la57() to use cpuinfo flag
- selftests/lam: Skip test if LAM is disabled
- selftests/lam: Test get_user() LAM pointer handling
AMD SMN access updates:
- Add SMN offsets to exclusive region access (Mario Limonciello)
- Add support for debugfs access to SMN registers (Mario Limonciello)
- Have HSMP use SMN through AMD_NODE (Yazen Ghannam)
Power management updates: (Patryk Wlazlyn)
- Allow calling mwait_play_dead with an arbitrary hint
- ACPI/processor_idle: Add FFH state handling
- intel_idle: Provide the default enter_dead() handler
- Eliminate mwait_play_dead_cpuid_hint()
Build system:
- Raise the minimum GCC version to 8.1 (Brian Gerst)
- Raise the minimum LLVM version to 15.0.0 (Nathan Chancellor)
Kconfig: (Arnd Bergmann)
- Add cmpxchg8b support back to Geode CPUs
- Drop 32-bit "bigsmp" machine support
- Rework CONFIG_GENERIC_CPU compiler flags
- Drop configuration options for early 64-bit CPUs
- Remove CONFIG_HIGHMEM64G support
- Drop CONFIG_SWIOTLB for PAE
- Drop support for CONFIG_HIGHPTE
- Document CONFIG_X86_INTEL_MID as 64-bit-only
- Remove old STA2x11 support
- Only allow CONFIG_EISA for 32-bit
Headers:
- Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI
headers (Thomas Huth)
Assembly code & machine code patching:
- x86/alternatives: Simplify alternative_call() interface (Josh
Poimboeuf)
- x86/alternatives: Simplify callthunk patching (Peter Zijlstra)
- KVM: VMX: Use named operands in inline asm (Josh Poimboeuf)
- x86/hyperv: Use named operands in inline asm (Josh Poimboeuf)
- x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra)
- x86/kexec: Merge x86_32 and x86_64 code using macros from
<asm/asm.h> (Uros Bizjak)
- Use named operands in inline asm (Uros Bizjak)
- Improve performance by using asm_inline() for atomic locking
instructions (Uros Bizjak)
Earlyprintk:
- Harden early_serial (Peter Zijlstra)
NMI handler:
- Add an emergency handler in nmi_desc & use it in
nmi_shootdown_cpus() (Waiman Long)
Miscellaneous fixes and cleanups:
- by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel, Artem
Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst, Dan
Carpenter, Dr. David Alan Gilbert, H. Peter Anvin, Ingo Molnar,
Josh Poimboeuf, Kevin Brodsky, Mike Rapoport, Lukas Bulwahn, Maciej
Wieczor-Retman, Max Grobecker, Patryk Wlazlyn, Pawan Gupta, Peter
Zijlstra, Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner,
Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak, Vitaly
Kuznetsov, Xin Li, liuye"
* tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (211 commits)
zstd: Increase DYNAMIC_BMI2 GCC version cutoff from 4.8 to 11.0 to work around compiler segfault
x86/asm: Make asm export of __ref_stack_chk_guard unconditional
x86/mm: Only do broadcast flush from reclaim if pages were unmapped
perf/x86/intel, x86/cpu: Replace Pentium 4 model checks with VFM ones
perf/x86/intel, x86/cpu: Simplify Intel PMU initialization
x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headers
x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI headers
x86/locking/atomic: Improve performance by using asm_inline() for atomic locking instructions
x86/asm: Use asm_inline() instead of asm() in clwb()
x86/asm: Use CLFLUSHOPT and CLWB mnemonics in <asm/special_insns.h>
x86/hweight: Use asm_inline() instead of asm()
x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm()
x86/hweight: Use named operands in inline asm()
x86/stackprotector/64: Only export __ref_stack_chk_guard on CONFIG_SMP
x86/head/64: Avoid Clang < 17 stack protector in startup code
x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h>
x86/runtime-const: Add the RUNTIME_CONST_PTR assembly macro
x86/cpu/intel: Limit the non-architectural constant_tsc model checks
x86/mm/pat: Replace Intel x86_model checks with VFM ones
x86/cpu/intel: Fix fast string initialization for extended Families
...
[ Merge note, these two commits are identical:
- f3fa0e40df ("sched/clock: Don't define sched_clock_irqtime as static key")
- b9f2b29b94 ("sched: Don't define sched_clock_irqtime as static key")
The first one is a cherry-picked version of the second, and the first one
is already upstream. ]
Core & fair scheduler changes:
- Cancel the slice protection of the idle entity (Zihan Zhou)
- Reduce the default slice to avoid tasks getting an extra tick
(Zihan Zhou)
- Force propagating min_slice of cfs_rq when {en,de}queue tasks
(Tianchen Ding)
- Refactor can_migrate_task() to elimate looping (I Hsin Cheng)
- Add unlikey branch hints to several system calls (Colin Ian King)
- Optimize current_clr_polling() on certain architectures (Yujun Dong)
Deadline scheduler: (Juri Lelli)
- Remove redundant dl_clear_root_domain call
- Move dl_rebuild_rd_accounting to cpuset.h
Uclamp:
- Use the uclamp_is_used() helper instead of open-coding it (Xuewen Yan)
- Optimize sched_uclamp_used static key enabling (Xuewen Yan)
Scheduler topology support: (Juri Lelli)
- Ignore special tasks when rebuilding domains
- Add wrappers for sched_domains_mutex
- Generalize unique visiting of root domains
- Rebuild root domain accounting after every update
- Remove partition_and_rebuild_sched_domains
- Stop exposing partition_sched_domains_locked
RSEQ: (Michael Jeanson)
- Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y
- Fix segfault on registration when rseq_cs is non-zero
- selftests: Add rseq syscall errors test
- selftests: Ensure the rseq ABI TLS is actually 1024 bytes
Membarriers:
- Fix redundant load of membarrier_state (Nysal Jan K.A.)
Scheduler debugging:
- Introduce and use preempt_model_str() (Sebastian Andrzej Siewior)
- Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar)
Fixes and cleanups:
- Always save/restore x86 TSC sched_clock() on suspend/resume
(Guilherme G. Piccoli)
- Misc fixes and cleanups (Thorsten Blum, Juri Lelli,
Sebastian Andrzej Siewior)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Core & fair scheduler changes:
- Cancel the slice protection of the idle entity (Zihan Zhou)
- Reduce the default slice to avoid tasks getting an extra tick
(Zihan Zhou)
- Force propagating min_slice of cfs_rq when {en,de}queue tasks
(Tianchen Ding)
- Refactor can_migrate_task() to elimate looping (I Hsin Cheng)
- Add unlikey branch hints to several system calls (Colin Ian King)
- Optimize current_clr_polling() on certain architectures (Yujun
Dong)
Deadline scheduler: (Juri Lelli)
- Remove redundant dl_clear_root_domain call
- Move dl_rebuild_rd_accounting to cpuset.h
Uclamp:
- Use the uclamp_is_used() helper instead of open-coding it (Xuewen
Yan)
- Optimize sched_uclamp_used static key enabling (Xuewen Yan)
Scheduler topology support: (Juri Lelli)
- Ignore special tasks when rebuilding domains
- Add wrappers for sched_domains_mutex
- Generalize unique visiting of root domains
- Rebuild root domain accounting after every update
- Remove partition_and_rebuild_sched_domains
- Stop exposing partition_sched_domains_locked
RSEQ: (Michael Jeanson)
- Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y
- Fix segfault on registration when rseq_cs is non-zero
- selftests: Add rseq syscall errors test
- selftests: Ensure the rseq ABI TLS is actually 1024 bytes
Membarriers:
- Fix redundant load of membarrier_state (Nysal Jan K.A.)
Scheduler debugging:
- Introduce and use preempt_model_str() (Sebastian Andrzej Siewior)
- Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar)
Fixes and cleanups:
- Always save/restore x86 TSC sched_clock() on suspend/resume
(Guilherme G. Piccoli)
- Misc fixes and cleanups (Thorsten Blum, Juri Lelli, Sebastian
Andrzej Siewior)"
* tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits)
cpuidle, sched: Use smp_mb__after_atomic() in current_clr_polling()
sched/debug: Remove CONFIG_SCHED_DEBUG
sched/debug: Remove CONFIG_SCHED_DEBUG from self-test config files
sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from documentation
sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditional
sched/debug: Make 'const_debug' tunables unconditional __read_mostly
sched/debug: Change SCHED_WARN_ON() to WARN_ON_ONCE()
rseq/selftests: Fix namespace collision with rseq UAPI header
include/{topology,cpuset}: Move dl_rebuild_rd_accounting to cpuset.h
sched/topology: Stop exposing partition_sched_domains_locked
cgroup/cpuset: Remove partition_and_rebuild_sched_domains
sched/topology: Remove redundant dl_clear_root_domain call
sched/deadline: Rebuild root domain accounting after every update
sched/deadline: Generalize unique visiting of root domains
sched/topology: Wrappers for sched_domains_mutex
sched/deadline: Ignore special tasks when rebuilding domains
tracing: Use preempt_model_str()
xtensa: Rely on generic printing of preemption model
x86: Rely on generic printing of preemption model
s390: Rely on generic printing of preemption model
...
This pull request contains the following branches:
docs.2025.02.04a:
- Add broken-timing possibility to stallwarn.rst.
- Improve discussion of this_cpu_ptr(), add raw_cpu_ptr().
- Document self-propagating callbacks.
- Point call_srcu() to call_rcu() for detailed memory ordering.
- Add CONFIG_RCU_LAZY delays to call_rcu() kernel-doc header.
- Clarify RCU_LAZY and RCU_LAZY_DEFAULT_OFF help text.
- Remove references to old grace-period-wait primitives.
srcu.2025.02.05a:
- Introduce srcu_read_{un,}lock_fast(), which is similar to
srcu_read_{un,}lock_lite(): avoid smp_mb()s in lock and unlock at the
cost of calling synchronize_rcu() in synchronize_srcu(). Moreover, by
returning the percpu offset of the counter at srcu_read_lock_fast()
time, srcu_read_unlock_fast() can save extra pointer dereferencing,
which makes it faster than srcu_read_{un,}lock_lite().
srcu_read_{un,}lock_fast() are intended to replace
rcu_read_{un,}lock_trace() if possible.
torture.2025.02.05a:
- Add get_torture_init_jiffies() to return the start time of the test.
- Add a test_boost_holdoff module parameter to allow delaying boosting
tests when building rcutorture as built-in.
- Add grace period sequence number logging at the beginning and end of
failure/close-call results.
- Switch to hexadecimal for the expedited grace period sequence number
in the rcu_exp_grace_period trace point.
- Make cur_ops->format_gp_seqs take buffer length.
- Move RCU_TORTURE_TEST_{CHK_RDR_STATE,LOG_CPU} to bool.
- Complain when invalid SRCU reader_flavor is specified.
- Add FORCE_NEED_SRCU_NMI_SAFE Kconfig for testing, which forces SRCU
uses atomics even when percpu ops are NMI safe, and use the Kconfig
for SRCU lockdep testing.
misc.2025.03.04a:
- Split rcu_report_exp_cpu_mult() mask parameter and use for tracing.
- Remove READ_ONCE() for rdp->gpwrap access in __note_gp_changes().
- Fix get_state_synchronize_rcu_full() GP-start detection.
- Move RCU Tasks self-tests to core_initcall().
- Print segment lengths in show_rcu_nocb_gp_state().
- Make RCU watch ct_kernel_exit_state() warning.
- Flush console log from kernel_power_off().
- rcutorture: Allow a negative value for nfakewriters.
- rcu: Update TREE05.boot to test normal synchronize_rcu().
- rcu: Use _full() API to debug synchronize_rcu().
lazypreempt.2025.03.04a: Make RCU handle PREEMPT_LAZY better:
- Fix header guard for rcu_all_qs().
- rcu: Rename PREEMPT_AUTO to PREEMPT_LAZY.
- Update __cond_resched comment about RCU quiescent states.
- Handle unstable rdp in rcu_read_unlock_strict().
- Handle quiescent states for PREEMPT_RCU=n, PREEMPT_COUNT=y.
- osnoise: Provide quiescent states.
- Adjust rcutorture with possible PREEMPT_RCU=n && PREEMPT_COUNT=y
combination.
- Limit PREEMPT_RCU configurations.
- Make rcutorture senario TREE07 and senario TREE10 use PREEMPT_LAZY=y.
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Merge tag 'rcu-next-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux
Pull RCU updates from Boqun Feng:
"Documentation:
- Add broken-timing possibility to stallwarn.rst
- Improve discussion of this_cpu_ptr(), add raw_cpu_ptr()
- Document self-propagating callbacks
- Point call_srcu() to call_rcu() for detailed memory ordering
- Add CONFIG_RCU_LAZY delays to call_rcu() kernel-doc header
- Clarify RCU_LAZY and RCU_LAZY_DEFAULT_OFF help text
- Remove references to old grace-period-wait primitives
srcu:
- Introduce srcu_read_{un,}lock_fast(), which is similar to
srcu_read_{un,}lock_lite(): avoid smp_mb()s in lock and unlock
at the cost of calling synchronize_rcu() in synchronize_srcu()
Moreover, by returning the percpu offset of the counter at
srcu_read_lock_fast() time, srcu_read_unlock_fast() can avoid
extra pointer dereferencing, which makes it faster than
srcu_read_{un,}lock_lite()
srcu_read_{un,}lock_fast() are intended to replace
rcu_read_{un,}lock_trace() if possible
RCU torture:
- Add get_torture_init_jiffies() to return the start time of the test
- Add a test_boost_holdoff module parameter to allow delaying
boosting tests when building rcutorture as built-in
- Add grace period sequence number logging at the beginning and end
of failure/close-call results
- Switch to hexadecimal for the expedited grace period sequence
number in the rcu_exp_grace_period trace point
- Make cur_ops->format_gp_seqs take buffer length
- Move RCU_TORTURE_TEST_{CHK_RDR_STATE,LOG_CPU} to bool
- Complain when invalid SRCU reader_flavor is specified
- Add FORCE_NEED_SRCU_NMI_SAFE Kconfig for testing, which forces SRCU
uses atomics even when percpu ops are NMI safe, and use the Kconfig
for SRCU lockdep testing
Misc:
- Split rcu_report_exp_cpu_mult() mask parameter and use for tracing
- Remove READ_ONCE() for rdp->gpwrap access in __note_gp_changes()
- Fix get_state_synchronize_rcu_full() GP-start detection
- Move RCU Tasks self-tests to core_initcall()
- Print segment lengths in show_rcu_nocb_gp_state()
- Make RCU watch ct_kernel_exit_state() warning
- Flush console log from kernel_power_off()
- rcutorture: Allow a negative value for nfakewriters
- rcu: Update TREE05.boot to test normal synchronize_rcu()
- rcu: Use _full() API to debug synchronize_rcu()
Make RCU handle PREEMPT_LAZY better:
- Fix header guard for rcu_all_qs()
- rcu: Rename PREEMPT_AUTO to PREEMPT_LAZY
- Update __cond_resched comment about RCU quiescent states
- Handle unstable rdp in rcu_read_unlock_strict()
- Handle quiescent states for PREEMPT_RCU=n, PREEMPT_COUNT=y
- osnoise: Provide quiescent states
- Adjust rcutorture with possible PREEMPT_RCU=n && PREEMPT_COUNT=y
combination
- Limit PREEMPT_RCU configurations
- Make rcutorture senario TREE07 and senario TREE10 use
PREEMPT_LAZY=y"
* tag 'rcu-next-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (59 commits)
rcutorture: Make scenario TREE07 build CONFIG_PREEMPT_LAZY=y
rcutorture: Make scenario TREE10 build CONFIG_PREEMPT_LAZY=y
rcu: limit PREEMPT_RCU configurations
rcutorture: Update ->extendables check for lazy preemption
rcutorture: Update rcutorture_one_extend_check() for lazy preemption
osnoise: provide quiescent states
rcu: Use _full() API to debug synchronize_rcu()
rcu: Update TREE05.boot to test normal synchronize_rcu()
rcutorture: Allow a negative value for nfakewriters
Flush console log from kernel_power_off()
context_tracking: Make RCU watch ct_kernel_exit_state() warning
rcu/nocb: Print segment lengths in show_rcu_nocb_gp_state()
rcu-tasks: Move RCU Tasks self-tests to core_initcall()
rcu: Fix get_state_synchronize_rcu_full() GP-start detection
torture: Make SRCU lockdep testing use srcu_read_lock_nmisafe()
srcu: Add FORCE_NEED_SRCU_NMI_SAFE Kconfig for testing
rcutorture: Complain when invalid SRCU reader_flavor is specified
rcutorture: Move RCU_TORTURE_TEST_{CHK_RDR_STATE,LOG_CPU} to bool
rcutorture: Make cur_ops->format_gp_seqs take buffer length
rcutorture: Add ftrace-compatible timestamp to GP# failure/close-call output
...
Add 3 per-cpu monitors as part of the sched model:
* scpd: schedule called with preemption disabled
Monitor to ensure schedule is called with preemption disabled
* snep: schedule does not enable preempt
Monitor to ensure schedule does not enable preempt
* sncid: schedule not called with interrupt disabled
Monitor to ensure schedule is not called with interrupt disabled
To: Ingo Molnar <mingo@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Link: https://lore.kernel.org/20250305140406.350227-6-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add a per-task monitor as part of the sched model:
* snroc: set non runnable on its own context
Monitor to ensure set_state happens only in the respective task's context
To: Ingo Molnar <mingo@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Link: https://lore.kernel.org/20250305140406.350227-5-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add 2 per-cpu monitors as part of the sched model:
* sco: scheduling context operations
Monitor to ensure sched_set_state happens only in thread context
* tss: task switch while scheduling
Monitor to ensure sched_switch happens only in scheduling context
To: Ingo Molnar <mingo@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Kacur <jkacur@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Link: https://lore.kernel.org/20250305140406.350227-4-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Monitors describing complex systems, such as the scheduler, can easily
grow to the point where they are just hard to understand because of the
many possible state transitions.
Often it is possible to break such descriptions into smaller monitors,
sharing some or all events. Enabling those smaller monitors concurrently
is, in fact, testing the system as if we had one single larger monitor.
Splitting models into multiple specification is not only easier to
understand, but gives some more clues when we see errors.
Add the possibility to create container monitors, whose only purpose is
to host other nested monitors. Enabling a container monitor enables all
nested ones, but it's still possible to enable nested monitors
independently.
Add the sched monitor as first container, for now empty.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/20250305140406.350227-3-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
An update was made to up the module ref count when a synthetic event is
registered for both trace and perf events. But if perf is not configured
in, the perf enums used will cause the kernel to fail to build.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Link: https://lore.kernel.org/20250323152151.528b5ced@batman.local.home
Fixes: 21581dd4e7 ("tracing: Ensure module defining synth event cannot be unloaded while tracing")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202503232230.TeREVy8R-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Convert the event_hash array in trace_output.c to use the generic
hashtable implementation from hashtable.h instead of the manually
implemented hash table.
This simplifies the code and makes it more maintainable by using the
standard hashtable API defined in hashtable.h.
Rename EVENT_HASHSIZE to EVENT_HASH_BITS to properly reflect its new
meaning as the number of bits for the hashtable size.
Link: https://lore.kernel.org/20250323132800.3010783-1-sashal@kernel.org
Link: https://lore.kernel.org/20250319190545.3058319-1-sashal@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Currently, using synth_event_delete() will fail if the event is being
used (tracing in progress), but that is normally done in the module exit
function. At that stage, failing is problematic as returning a non-zero
status means the module will become locked (impossible to unload or
reload again).
Instead, ensure the module exit function does not get called in the
first place by increasing the module refcnt when the event is enabled.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 35ca5207c2 ("tracing: Add synthetic event command generation functions")
Link: https://lore.kernel.org/20250318180906.226841-1-douglas.raillard@arm.com
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When __ftrace_event_enable_disable invokes the class callback to
unregister the event, the return value is not reported up to the
caller, hence leading to event unregister failures being silently
ignored.
This patch assigns the ret variable to the invocation of the
event unregister callback, so that its return value is stored
and reported to the caller, and it raises a warning in case
of error.
Link: https://lore.kernel.org/20250321170821.101403-1-gpaoloni@redhat.com
Signed-off-by: Gabriele Paoloni <gpaoloni@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Lockdep reports this deadlock log:
osnoise: could not start sampling thread
============================================
WARNING: possible recursive locking detected
--------------------------------------------
CPU0
----
lock(cpu_hotplug_lock);
lock(cpu_hotplug_lock);
Call Trace:
<TASK>
print_deadlock_bug+0x282/0x3c0
__lock_acquire+0x1610/0x29a0
lock_acquire+0xcb/0x2d0
cpus_read_lock+0x49/0x120
stop_per_cpu_kthreads+0x7/0x60
start_kthread+0x103/0x120
osnoise_hotplug_workfn+0x5e/0x90
process_one_work+0x44f/0xb30
worker_thread+0x33e/0x5e0
kthread+0x206/0x3b0
ret_from_fork+0x31/0x50
ret_from_fork_asm+0x11/0x20
</TASK>
This is the deadlock scenario:
osnoise_hotplug_workfn()
guard(cpus_read_lock)(); // first lock call
start_kthread(cpu)
if (IS_ERR(kthread)) {
stop_per_cpu_kthreads(); {
cpus_read_lock(); // second lock call. Cause the AA deadlock
}
}
It is not necessary to call stop_per_cpu_kthreads() which stops osnoise
kthread for every other CPUs in the system if a failure occurs during
hotplug of a certain CPU.
For start_per_cpu_kthreads(), if the start_kthread() call fails,
this function calls stop_per_cpu_kthreads() to handle the error.
Therefore, similarly, there is no need to call stop_per_cpu_kthreads()
again within start_kthread().
So just remove stop_per_cpu_kthreads() from start_kthread to solve this issue.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250321095249.2739397-1-ranxiaokai627@163.com
Fixes: c8895e271f ("trace/osnoise: Support hotplug operations")
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The vast majority of ftrace event print fmt consist of a space-separated
field=value pair. Synthetic event currently use a comma-separated
field=value pair, which sticks out from events created via more
classical means.
Align the format of synth events so they look just like any other event,
for better consistency and less headache when doing crude text-based
data processing.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250319215028.1680278-1-douglas.raillard@arm.com
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Kairui reported a UAF issue in print_graph_function_flags() during
ftrace stress testing [1]. This issue can be reproduced if puting a
'mdelay(10)' after 'mutex_unlock(&trace_types_lock)' in s_start(),
and executing the following script:
$ echo function_graph > current_tracer
$ cat trace > /dev/null &
$ sleep 5 # Ensure the 'cat' reaches the 'mdelay(10)' point
$ echo timerlat > current_tracer
The root cause lies in the two calls to print_graph_function_flags
within print_trace_line during each s_show():
* One through 'iter->trace->print_line()';
* Another through 'event->funcs->trace()', which is hidden in
print_trace_fmt() before print_trace_line returns.
Tracer switching only updates the former, while the latter continues
to use the print_line function of the old tracer, which in the script
above is print_graph_function_flags.
Moreover, when switching from the 'function_graph' tracer to the
'timerlat' tracer, s_start only calls graph_trace_close of the
'function_graph' tracer to free 'iter->private', but does not set
it to NULL. This provides an opportunity for 'event->funcs->trace()'
to use an invalid 'iter->private'.
To fix this issue, set 'iter->private' to NULL immediately after
freeing it in graph_trace_close(), ensuring that an invalid pointer
is not passed to other tracers. Additionally, clean up the unnecessary
'iter->private = NULL' during each 'cat trace' when using wakeup and
irqsoff tracers.
[1] https://lore.kernel.org/all/20231112150030.84609-1-ryncsn@gmail.com/
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Link: https://lore.kernel.org/20250320122137.23635-1-wutengda@huaweicloud.com
Fixes: eecb91b9f9 ("tracing: Fix memleak due to race between current_tracer and trace")
Closes: https://lore.kernel.org/all/CAMgjq7BW79KDSCyp+tZHjShSzHsScSiJxn5ffskp-QzVM06fxw@mail.gmail.com/
Reported-by: Kairui Song <kasong@tencent.com>
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
'event_trigger_ops mwifiex_if_ops' are not modified in these drivers.
Constifying these structures moves some data to a read-only section, so
increase overall security, especially when the structure holds some
function pointers.
On a x86_64, with allmodconfig, as an example:
Before:
======
text data bss dec hex filename
31368 9024 6200 46592 b600 kernel/trace/trace_events_trigger.o
After:
=====
text data bss dec hex filename
31752 8608 6200 46560 b5e0 kernel/trace/trace_events_trigger.o
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/66e8f990e649678e4be37d4d1a19158ca0dea2f4.1741521295.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The perf_event_read_event_output helper is currently only available to
tracing protrams, but is useful for other BPF programs like sched_ext
schedulers. When the helper is available, provide its bpf_func_proto
directly from the bpf base_proto.
Signed-off-by: Emil Tsalapatis (Meta) <emil@etsalapatis.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20250318030753.10949-1-emil@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
- tprobe-events: Fix to clean up tprobe correctly when module unload
tprobe (Tracepoint probe) event does not set TRACEPOINT_STUB to its
'tpoint' pointer when unloading module, thus it is shown as a normal
'fprobe' instead of 'tprobe' and never comes back.
- tprobe-events: Fix leakage of module refcount
When a tprobe's target module is loaded, it gets the module's refcount
in the module notifier but forgot to put it after registering the probe
on it. Fix to get the refcount only when registering tprobe.
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Merge tag 'probes-fixes-v6.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fixes from Masami Hiramatsu:
- Clean up tprobe correctly when module unload
Tracepoint probes do not set TRACEPOINT_STUB on the 'tpoint' pointer
when unloading a module, thus they show as a normal 'fprobe' instead
of 'tprobe' and never come back
- Fix leakage of tprobe module refcount
When a tprobe's target module is loaded, it gets the module's
refcount in the module notifier but forgot to put it after
registering the probe on it.
Fix it by getting the refcount only when registering tprobe.
* tag 'probes-fixes-v6.14-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: tprobe-events: Fix leakage of module refcount
tracing: tprobe-events: Fix to clean up tprobe correctly when module unload
Use preempt_model_str() instead of manually conducting the preemption
model.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20250314160810.2373416-10-bigeasy@linutronix.de
Tracing instances have a ref count to keep them around while files within
their directories are open. This prevents them from being deleted while
they are used. The histogram code had some files that needed to take the
ref count and that was added, but the error paths did not decrement the
ref counts. This caused the instances from ever being removed if a
histogram file failed to open due to some error.
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Merge tag 'trace-v6.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fix from Steven Rostedt:
"Fix ref count of trace_array in error path of histogram file open
Tracing instances have a ref count to keep them around while files
within their directories are open. This prevents them from being
deleted while they are used.
The histogram code had some files that needed to take the ref count
and that was added, but the error paths did not decrement the ref
counts. This caused the instances from ever being removed if a
histogram file failed to open due to some error"
* tag 'trace-v6.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Correct the refcount if the hist/hist_debug file fails to open
When enabling the tracepoint at loading module, the target module
refcount is incremented by find_tracepoint_in_module(). But it is
unnecessary because the module is not unloaded while processing
module loading callbacks.
Moreover, the refcount is not decremented in that function.
To be clear the module refcount handling, move the try_module_get()
callsite to trace_fprobe_create_internal(), where it is actually
required.
Link: https://lore.kernel.org/all/174182761071.83274.18334217580449925882.stgit@devnote2/
Fixes: 57a7e6de9e ("tracing/fprobe: Support raw tracepoints on future loaded modules")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
When unloading module, the tprobe events are not correctly cleaned
up. Thus it becomes `fprobe-event` and never be enabled again even
if loading the same module again.
For example;
# cd /sys/kernel/tracing
# modprobe trace_events_sample
# echo 't:my_tprobe foo_bar' >> dynamic_events
# cat dynamic_events
t:tracepoints/my_tprobe foo_bar
# rmmod trace_events_sample
# cat dynamic_events
f:tracepoints/my_tprobe foo_bar
As you can see, the second time my_tprobe starts with 'f' instead
of 't'.
This unregisters the fprobe and tracepoint callback when module is
unloaded but marks the fprobe-event is tprobe-event.
Link: https://lore.kernel.org/all/174158724946.189309.15826571379395619524.stgit@mhiramat.tok.corp.google.com/
Fixes: 57a7e6de9e ("tracing/fprobe: Support raw tracepoints on future loaded modules")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
The function event_{hist,hist_debug}_open() maintains the refcount of
'file->tr' and 'file' through tracing_open_file_tr(). However, it does
not roll back these counts on subsequent failure paths, resulting in a
refcount leak.
A very obvious case is that if the hist/hist_debug file belongs to a
specific instance, the refcount leak will prevent the deletion of that
instance, as it relies on the condition 'tr->ref == 1' within
__remove_instance().
Fix this by calling tracing_release_file_tr() on all failure paths in
event_{hist,hist_debug}_open() to correct the refcount.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Link: https://lore.kernel.org/20250314065335.1202817-1-wutengda@huaweicloud.com
Fixes: 1cc111b9cd ("tracing: Fix uaf issue when open the hist or hist_debug file")
Signed-off-by: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
__module_address() can be invoked within a RCU section, there is no
requirement to have preemption disabled.
Replace the preempt_disable() section around __module_address() with
RCU.
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matt Bobrowski <mattbobrowski@google.com>
Cc: Song Liu <song@kernel.org>
Cc: Stanislav Fomichev <sdf@fomichev.me>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Yonghong Song <yonghong.song@linux.dev>
Cc: bpf@vger.kernel.org
Cc: linux-trace-kernel@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20250129084751.tH6iidUO@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
The modules list and module::kallsyms can be accessed under RCU
assumption.
Remove module_assert_mutex_or_preempt() from find_module_all() so it can
be used under RCU protection without warnings. Update its callers to use
RCU protection instead of preempt_disable().
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-trace-kernel@vger.kernel.org
Cc: live-patching@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20250108090457.512198-7-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Variable func is not effectively used, so delete it.
kernel/trace/trace_functions_graph.c:925:16: warning: variable ‘func’ set but not used.
This happened because the variable "func" which came from "call->func" was
replaced by "ret_func" coming from "graph_ret->func" but "func" wasn't
removed after the replacement.
Link: https://lore.kernel.org/20250307021412.119107-1-jiapeng.chong@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=19250
Fixes: ff5c9c576e ("ftrace: Add support for function argument to graph tracer")
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2 seq_puts() calls can be merged.
It saves a few lines of code and a few cycles, should it matter.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/845caa94b74cea8d72c158bf1994fe250beee28c.1739979791.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
To reduce RCU noise for nohz_full configurations, osnoise depends
on cond_resched() providing quiescent states for PREEMPT_RCU=n
configurations. For PREEMPT_RCU=y configurations -- where
cond_resched() is a stub -- we do this by directly calling
rcu_momentary_eqs().
With (PREEMPT_LAZY=y, PREEMPT_DYNAMIC=n), however, we have a
configuration with (PREEMPTION=y, PREEMPT_RCU=n) where neither
of the above can help.
Handle that by providing an explicit quiescent state here for all
configurations.
As mentioned above this is not needed for non-stubbed cond_resched(),
but, providing a quiescent state here just pulls in one that a future
cond_resched() would provide, so doesn't cause any extra work for
this configuration.
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Some monitor files like the main header and the Kconfig are missing the
license identifier.
Add it to those and make sure the automatic generation script includes
the line in newly created monitors.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/20250218123121.253551-3-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Wire up the code to print function arguments in the function tracer.
This functionality can be enabled/disabled during runtime with
options/func-args.
ping-689 [004] b.... 77.170220: dummy_xmit(skb = 0x82904800, dev = 0x882d0000) <-dev_hard_start_xmit
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Guo Ren <guoren@kernel.org>
Cc: Donglin Peng <dolinux.peng@gmail.com>
Cc: Zheng Yejian <zhengyejian@huaweicloud.com>
Link: https://lore.kernel.org/20250227185823.154996172@goodmis.org
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Co-developed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Currently, when function_graph is started, it looks at the option
funcgraph-args, and if it is set, it will enable tracing of the arguments.
But if tracing is already running, and the user enables funcgraph-args, it
will have no effect. Instead, it should enable argument tracing when it is
enabled, even if it means disabling the function graph tracing for a short
time in order to do the transition.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Guo Ren <guoren@kernel.org>
Cc: Donglin Peng <dolinux.peng@gmail.com>
Cc: Zheng Yejian <zhengyejian@huaweicloud.com>
Link: https://lore.kernel.org/20250227185822.978998710@goodmis.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Wire up the code to print function arguments in the function graph
tracer. This functionality can be enabled/disabled during runtime with
options/funcgraph-args.
Example usage:
6) | dummy_xmit [dummy](skb = 0x8887c100, dev = 0x872ca000) {
6) | consume_skb(skb = 0x8887c100) {
6) | skb_release_head_state(skb = 0x8887c100) {
6) 0.178 us | sock_wfree(skb = 0x8887c100)
6) 0.627 us | }
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Guo Ren <guoren@kernel.org>
Cc: Donglin Peng <dolinux.peng@gmail.com>
Cc: Zheng Yejian <zhengyejian@huaweicloud.com>
Link: https://lore.kernel.org/20250227185822.810321199@goodmis.org
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Co-developed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add a function to decode argument types with the help of BTF. Will
be used to display arguments in the function and function graph
tracer.
It can only handle simply arguments and up to FTRACE_REGS_MAX_ARGS number
of arguments. When it hits a max, it will print ", ...":
page_to_skb(vi=0xffff8d53842dc980, rq=0xffff8d53843a0800, page=0xfffffc2e04337c00, offset=6160, len=64, truesize=1536, ...)
And if it hits an argument that is not recognized, it will print the raw
value and the type of argument it is:
make_vfsuid(idmap=0xffffffff87f99db8, fs_userns=0xffffffff87e543c0, kuid=0x0 (STRUCT))
__pti_set_user_pgtbl(pgdp=0xffff8d5384ab47f8, pgd=0x110e74067 (STRUCT))
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Guo Ren <guoren@kernel.org>
Cc: Donglin Peng <dolinux.peng@gmail.com>
Cc: Zheng Yejian <zhengyejian@huaweicloud.com>
Link: https://lore.kernel.org/20250227185822.639418500@goodmis.org
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Co-developed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The ftrace_free_filter() is used to reset the ops filters. But it must be
done if the ops is not currently active (tracing). If it is, it will mess
up the ftrace accounting of what functions are attached and what is not.
WARN and exit the ftrace_free_filter() if the ops is active when it is
called.
Currently, it doesn't seem if anything does this, but it may in the
future.
Link: https://lore.kernel.org/all/20250219095330.2e9f171c@gandalf.local.home/
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250219135040.3a9fbe00@gandalf.local.home
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- probe-events: Some issues are fixed.
. probe-events: Remove unused MAX_ARG_BUF_LEN macro.
MAX_ARG_BUF_LEN is not used so remove it.
. fprobe-events: Log error for exceeding the number of entry args.
Since the max number of entry args is limited, it should be checked
and rejected when the parser detects it.
. tprobe-events: Reject invalid tracepoint name
User can specify an invalid tracepoint name e.g. including '/', then
the new event is not defined correctly in the eventfs.
. tprobe-events: Fix a memory leak when tprobe defined with $retval
There is a memory leak if tprobe is defined with $retval.
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Merge tag 'probes-fixes-v6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probe events fixes from Masami Hiramatsu:
- probe-events: Remove unused MAX_ARG_BUF_LEN macro - it is not used
- fprobe-events: Log error for exceeding the number of entry args.
Since the max number of entry args is limited, it should be checked
and rejected when the parser detects it.
- tprobe-events: Reject invalid tracepoint name
If a user specifies an invalid tracepoint name (e.g. including '/')
then the new event is not defined correctly in the eventfs.
- tprobe-events: Fix a memory leak when tprobe defined with $retval
There is a memory leak if tprobe is defined with $retval.
* tag 'probes-fixes-v6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: probe-events: Remove unused MAX_ARG_BUF_LEN macro
tracing: fprobe-events: Log error for exceeding the number of entry args
tracing: tprobe-events: Reject invalid tracepoint name
tracing: tprobe-events: Fix a memory leak when tprobe with $retval
Check whether denominator expression x * (x - 1) * 1000 mod {2^32, 2^64}
produce zero and skip stddev computation in that case.
For now don't care about rec->counter * rec->counter overflow because
rec->time * rec->time overflow will likely happen earlier.
Cc: stable@vger.kernel.org
Cc: Wen Yang <wenyang@linux.alibaba.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250206090156.1561783-1-kniv@yandex-team.ru
Fixes: e31f7939c1 ("ftrace: Avoid potential division by zero in function profiler")
Signed-off-by: Nikolay Kuratov <kniv@yandex-team.ru>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The following commands causes a crash:
~# cd /sys/kernel/tracing/events/rcu/rcu_callback
~# echo 'hist:name=bad:keys=common_pid:onmax(bogus).save(common_pid)' > trigger
bash: echo: write error: Invalid argument
~# echo 'hist:name=bad:keys=common_pid' > trigger
Because the following occurs:
event_trigger_write() {
trigger_process_regex() {
event_hist_trigger_parse() {
data = event_trigger_alloc(..);
event_trigger_register(.., data) {
cmd_ops->reg(.., data, ..) [hist_register_trigger()] {
data->ops->init() [event_hist_trigger_init()] {
save_named_trigger(name, data) {
list_add(&data->named_list, &named_triggers);
}
}
}
}
ret = create_actions(); (return -EINVAL)
if (ret)
goto out_unreg;
[..]
ret = hist_trigger_enable(data, ...) {
list_add_tail_rcu(&data->list, &file->triggers); <<<---- SKIPPED!!! (this is important!)
[..]
out_unreg:
event_hist_unregister(.., data) {
cmd_ops->unreg(.., data, ..) [hist_unregister_trigger()] {
list_for_each_entry(iter, &file->triggers, list) {
if (!hist_trigger_match(data, iter, named_data, false)) <- never matches
continue;
[..]
test = iter;
}
if (test && test->ops->free) <<<-- test is NULL
test->ops->free(test) [event_hist_trigger_free()] {
[..]
if (data->name)
del_named_trigger(data) {
list_del(&data->named_list); <<<<-- NEVER gets removed!
}
}
}
}
[..]
kfree(data); <<<-- frees item but it is still on list
The next time a hist with name is registered, it causes an u-a-f bug and
the kernel can crash.
Move the code around such that if event_trigger_register() succeeds, the
next thing called is hist_trigger_enable() which adds it to the list.
A bunch of actions is called if get_named_trigger_data() returns false.
But that doesn't need to be called after event_trigger_register(), so it
can be moved up, allowing event_trigger_register() to be called just
before hist_trigger_enable() keeping them together and allowing the
file->triggers to be properly populated.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250227163944.1c37f85f@gandalf.local.home
Fixes: 067fe038e7 ("tracing: Add variable reference handling to hist triggers")
Reported-by: Tomas Glozar <tglozar@redhat.com>
Tested-by: Tomas Glozar <tglozar@redhat.com>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Closes: https://lore.kernel.org/all/CAP4=nvTsxjckSBTz=Oe_UYh8keD9_sZC4i++4h72mJLic4_W4A@mail.gmail.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add trace events that fire at osnoise and timerlat sample generation, in
addition to the already existing noise and threshold events.
This allows processing the samples directly in the kernel, either with
ftrace triggers or with BPF.
Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Link: https://lore.kernel.org/20250203090418.1458923-1-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Tested-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add error message when the number of entry argument exceeds the
maximum size of entry data.
This is currently checked when registering fprobe, but in this case
no error message is shown in the error_log file.
Link: https://lore.kernel.org/all/174055074269.4079315.17809232650360988538.stgit@mhiramat.tok.corp.google.com/
Fixes: 25f00e40ce ("tracing/probes: Support $argN in return probe (kprobe and fprobe)")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Commit 57a7e6de9e ("tracing/fprobe: Support raw tracepoints on
future loaded modules") allows user to set a tprobe on non-exist
tracepoint but it does not check the tracepoint name is acceptable.
So it leads tprobe has a wrong character for events (e.g. with
subsystem prefix). In this case, the event is not shown in the
events directory.
Reject such invalid tracepoint name.
The tracepoint name must consist of alphabet or digit or '_'.
Link: https://lore.kernel.org/all/174055073461.4079315.15875502830565214255.stgit@mhiramat.tok.corp.google.com/
Fixes: 57a7e6de9e ("tracing/fprobe: Support raw tracepoints on future loaded modules")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: stable@vger.kernel.org
Fix a memory leak when a tprobe is defined with $retval. This
combination is not allowed, but the parse_symbol_and_return() does
not free the *symbol which should not be used if it returns the error.
Thus, it leaks the *symbol memory in that error path.
Link: https://lore.kernel.org/all/174055072650.4079315.3063014346697447838.stgit@mhiramat.tok.corp.google.com/
Fixes: ce51e6153f ("tracing: fprobe-event: Fix to check tracepoint event and return")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: stable@vger.kernel.org
It seems that the attr parameter was never been used in security
checks since it was first introduced by:
commit da97e18458 ("perf_event: Add support for LSM and SELinux checks")
so remove it.
Signed-off-by: Luo Gengkun <luogengkun@huaweicloud.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Fix the following deadlock:
CPU A
_free_event()
perf_kprobe_destroy()
mutex_lock(&event_mutex)
perf_trace_event_unreg()
synchronize_rcu_tasks_trace()
There are several paths where _free_event() grabs event_mutex
and calls sync_rcu_tasks_trace. Above is one such case.
CPU B
bpf_prog_test_run_syscall()
rcu_read_lock_trace()
bpf_prog_run_pin_on_cpu()
bpf_prog_load()
bpf_tracing_func_proto()
trace_set_clr_event()
mutex_lock(&event_mutex)
Delegate trace_set_clr_event() to workqueue to avoid
such lock dependency.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250224221637.4780-1-alexei.starovoitov@gmail.com
Sometimes tracing is used to debug issues during the boot process. Since
the trace buffer has a limited amount of storage, it may be prudent to
disable tracing after the boot is finished, otherwise the critical
information may be overwritten. With this option, the main tracing buffer
will be turned off at the end of the boot process.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: https://lore.kernel.org/20250208103017.48a7ec83@batman.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
As kaslr_offset() is architecture dependent and also may not be defined by
all architectures, when zeroing out unused weak functions, do not check
against kaslr_offset(), but instead check if the address is within the
kernel text sections. If KASLR added a shift to the zeroed out function,
it would still not be located in the kernel text. This is a more robust
way to test if the text is valid or not.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: "Arnd Bergmann" <arnd@arndb.de>
Link: https://lore.kernel.org/20250225182054.471759017@goodmis.org
Fixes: ef378c3b82 ("scripts/sorttable: Zero out weak functions in mcount_loc table")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Mark Brown <broonie@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/all/20250224180805.GA1536711@ax162/
Closes: https://lore.kernel.org/all/5225b07b-a9b2-4558-9d5f-aa60b19f6317@sirena.org.uk/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The addresses in the mcount_loc can be zeroed and then moved by KASLR
making them invalid addresses. ftrace_call_addr() for ARM 64 expects a
valid address to kernel text. If the addr read from the mcount_loc section
is invalid, it must not call ftrace_call_addr(). Move the addr check
before calling ftrace_call_addr() in ftrace_process_locs().
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/20250225182054.290128736@goodmis.org
Fixes: ef378c3b82 ("scripts/sorttable: Zero out weak functions in mcount_loc table")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: "Arnd Bergmann" <arnd@arndb.de>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/all/20250225025631.GA271248@ax162/
Closes: https://lore.kernel.org/all/91523154-072b-437b-bbdc-0b70e9783fd0@app.fastmail.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
kmemleak reports the following memory leak after reading set_event file:
# cat /sys/kernel/tracing/set_event
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xff110001234449e0 (size 16):
comm "cat", pid 13645, jiffies 4294981880
hex dump (first 16 bytes):
01 00 00 00 00 00 00 00 a8 71 e7 84 ff ff ff ff .........q......
backtrace (crc c43abbc):
__kmalloc_cache_noprof+0x3ca/0x4b0
s_start+0x72/0x2d0
seq_read_iter+0x265/0x1080
seq_read+0x2c9/0x420
vfs_read+0x166/0xc30
ksys_read+0xf4/0x1d0
do_syscall_64+0x79/0x150
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The issue can be reproduced regardless of whether set_event is empty or
not. Here is an example about the valid content of set_event.
# cat /sys/kernel/tracing/set_event
sched:sched_process_fork
sched:sched_switch
sched:sched_wakeup
*:*:mod:trace_events_sample
The root cause is that s_next() returns NULL when nothing is found.
This results in s_stop() attempting to free a NULL pointer because its
parameter is NULL.
Fix the issue by freeing the memory appropriately when s_next() fails
to find anything.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250220031528.7373-1-ahuang12@lenovo.com
Fixes: b355247df1 ("tracing: Cache ":mod:" events for modules not loaded yet")
Signed-off-by: Adrian Huang <ahuang12@lenovo.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function tracer should record the preemption level at the point when
the function is invoked. If the tracing subsystem decrement the
preemption counter it needs to correct this before feeding the data into
the trace buffer. This was broken in the commit cited below while
shifting the preempt-disabled section.
Use tracing_gen_ctx_dec() which properly subtracts one from the
preemption counter on a preemptible kernel.
Cc: stable@vger.kernel.org
Cc: Wander Lairson Costa <wander@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/20250220140749.pfw8qoNZ@linutronix.de
Fixes: ce5e48036c ("ftrace: disable preemption when recursion locked")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When adding a new fprobe, it will update the function hash to the
functions the fprobe is attached to and register with function graph to
have it call the registered functions. The fprobe_graph_active variable
keeps track of the number of fprobes that are using function graph.
If two fprobes attach to the same function, it increments the
fprobe_graph_active for each of them. But when they are removed, the first
fprobe to be removed will see that the function it is attached to is also
used by another fprobe and it will not remove that function from
function_graph. The logic will skip decrementing the fprobe_graph_active
variable.
This causes the fprobe_graph_active variable to not go to zero when all
fprobes are removed, and in doing so it does not unregister from
function graph. As the fgraph ops hash will now be empty, and an empty
filter hash means all functions are enabled, this triggers function graph
to add a callback to the fprobe infrastructure for every function!
# echo "f:myevent1 kernel_clone" >> /sys/kernel/tracing/dynamic_events
# echo "f:myevent2 kernel_clone%return" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc0024000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# > /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
trace_initcall_start_cb (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
run_init_process (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
try_to_run_init_process (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
x86_pmu_show_pmu_cap (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
cleanup_rapl_pmus (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
uncore_free_pcibus_map (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
uncore_types_exit (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
uncore_pci_exit.part.0 (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
kvm_shutdown (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
vmx_dump_msrs (1) tramp: 0xffffffffc0026000 (function_trace_call+0x0/0x170) ->function_trace_call+0x0/0x170
[..]
# cat /sys/kernel/tracing/enabled_functions | wc -l
54702
If a fprobe is being removed and all its functions are also traced by
other fprobes, still decrement the fprobe_graph_active counter.
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.565129766@goodmis.org
Fixes: 4346ba1604 ("fprobe: Rewrite fprobe on function-graph tracer")
Closes: https://lore.kernel.org/all/20250217114918.10397-A-hca@linux.ibm.com/
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When the last fprobe is removed, it calls unregister_ftrace_graph() to
remove the graph_ops from function graph. The issue is when it does so, it
calls return before removing the function from its graph ops via
ftrace_set_filter_ips(). This leaves the last function lingering in the
fprobe's fgraph ops and if a probe is added it also enables that last
function (even though the callback will just drop it, it does add unneeded
overhead to make that call).
# echo "f:myevent1 kernel_clone" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc02f3000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# echo "f:myevent2 schedule_timeout" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc02f3000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
schedule_timeout (1) tramp: 0xffffffffc02f3000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# > /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
# echo "f:myevent3 kmem_cache_free" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kmem_cache_free (1) tramp: 0xffffffffc0219000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
schedule_timeout (1) tramp: 0xffffffffc0219000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
The above enabled a fprobe on kernel_clone, and then on schedule_timeout.
The content of the enabled_functions shows the functions that have a
callback attached to them. The fprobe attached to those functions
properly. Then the fprobes were cleared, and enabled_functions was empty
after that. But after adding a fprobe on kmem_cache_free, the
enabled_functions shows that the schedule_timeout was attached again. This
is because it was still left in the fprobe ops that is used to tell
function graph what functions it wants callbacks from.
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.393254452@goodmis.org
Fixes: 4346ba1604 ("fprobe: Rewrite fprobe on function-graph tracer")
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Check if a function is already in the manager ops of a subops. A manager
ops contains multiple subops, and if two or more subops are tracing the
same function, the manager ops only needs a single entry in its hash.
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.226762894@goodmis.org
Fixes: 4f554e9556 ("ftrace: Add ftrace_set_filter_ips function")
Tested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Function graph uses a subops and manager ops mechanism to attach to
ftrace. The manager ops connects to ftrace and the functions it connects
to is defined by a list of subops that it manages.
The function hash that defines what the above ops attaches to limits the
functions to attach if the hash has any content. If the hash is empty, it
means to trace all functions.
The creation of the manager ops hash is done by iterating over all the
subops hashes. If any of the subops hashes is empty, it means that the
manager ops hash must trace all functions as well.
The issue is in the creation of the manager ops. When a second subops is
attached, a new hash is created by starting it as NULL and adding the
subops one at a time. But the NULL ops is mistaken as an empty hash, and
once an empty hash is found, it stops the loop of subops and just enables
all functions.
# echo "f:myevent1 kernel_clone" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
kernel_clone (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
# echo "f:myevent2 schedule_timeout" >> /sys/kernel/tracing/dynamic_events
# cat /sys/kernel/tracing/enabled_functions
trace_initcall_start_cb (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
run_init_process (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
try_to_run_init_process (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
x86_pmu_show_pmu_cap (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
cleanup_rapl_pmus (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_free_pcibus_map (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_types_exit (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
uncore_pci_exit.part.0 (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
kvm_shutdown (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
vmx_dump_msrs (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
vmx_cleanup_l1d_flush (1) tramp: 0xffffffffc0309000 (ftrace_graph_func+0x0/0x60) ->ftrace_graph_func+0x0/0x60
[..]
Fix this by initializing the new hash to NULL and if the hash is NULL do
not treat it as an empty hash but instead allocate by copying the content
of the first sub ops. Then on subsequent iterations, the new hash will not
be NULL, but the content of the previous subops. If that first subops
attached to all functions, then new hash may assume that the manager ops
also needs to attach to all functions.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250220202055.060300046@goodmis.org
Fixes: 5fccc7552c ("ftrace: Add subops logic to allow one ops to manage many")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
bpf_send_signal_common() uses preemptible() to check whether or not the
current context is preemptible. If it is preemptible, it will use
irq_work to send the signal asynchronously instead of trying to hold a
spin-lock, because spin-lock is sleepable under PREEMPT_RT.
However, preemptible() depends on CONFIG_PREEMPT_COUNT. When
CONFIG_PREEMPT_COUNT is turned off (e.g., CONFIG_PREEMPT_VOLUNTARY=y),
!preemptible() will be evaluated as 1 and bpf_send_signal_common() will
use irq_work unconditionally.
Fix it by unfolding "!preemptible()" and using "preempt_count() != 0 ||
irqs_disabled()" instead.
Fixes: 87c544108b ("bpf: Send signals asynchronously if !preemptible")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20250220042259.1583319-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The amount of memory that ftrace uses to save the descriptors to manage
the functions it can trace is shown at output. But if there are a lot of
functions that are skipped because they were weak or the architecture
added holes into the tables, then the extra pages that were allocated are
freed. But these freed pages are not reflected in the numbers shown, and
they can even be inconsistent with what is reported:
ftrace: allocating 57482 entries in 225 pages
ftrace: allocated 224 pages with 3 groups
The above shows the number of original entries that are in the mcount_loc
section and the pages needed to save them (225), but the second output
reflects the number of pages that were actually used. The two should be
consistent as:
ftrace: allocating 56739 entries in 224 pages
ftrace: allocated 224 pages with 3 groups
The above also shows the accurate number of entires that were actually
stored and does not include the entries that were removed.
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200023.221100846@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Now that weak functions turn into skipped entries, update the check to
make sure the amount that was allocated would fit both the entries that
were allocated as well as those that were skipped.
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200023.055162048@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When a function is annotated as "weak" and is overridden, the code is not
removed. If it is traced, the fentry/mcount location in the weak function
will be referenced by the "__mcount_loc" section. This will then be added
to the available_filter_functions list. Since only the address of the
functions are listed, to find the name to show, a search of kallsyms is
used.
Since kallsyms will return the function by simply finding the function
that the address is after but before the next function, an address of a
weak function will show up as the function before it. This is because
kallsyms does not save names of weak functions. This has caused issues in
the past, as now the traced weak function will be listed in
available_filter_functions with the name of the function before it.
At best, this will cause the previous function's name to be listed twice.
At worse, if the previous function was marked notrace, it will now show up
as a function that can be traced. Note that it only shows up that it can
be traced but will not be if enabled, which causes confusion.
https://lore.kernel.org/all/20220412094923.0abe90955e5db486b7bca279@kernel.org/
The commit b39181f7c6 ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid
adding weak function") was a workaround to this by checking the function
address before printing its name. If the address was too far from the
function given by the name then instead of printing the name it would
print: __ftrace_invalid_address___<invalid-offset>
The real issue is that these invalid addresses are listed in the ftrace
table look up which available_filter_functions is derived from. A place
holder must be listed in that file because set_ftrace_filter may take a
series of indexes into that file instead of names to be able to do O(1)
lookups to enable filtering (many tools use this method).
Even if kallsyms saved the size of the function, it does not remove the
need of having these place holders. The real solution is to not add a weak
function into the ftrace table in the first place.
To solve this, the sorttable.c code that sorts the mcount regions during
the build is modified to take a "nm -S vmlinux" input, sort it, and any
function listed in the mcount_loc section that is not within a boundary of
the function list given by nm is considered a weak function and is zeroed
out.
Note, this does not mean they will remain zero when booting as KASLR
will still shift those addresses. To handle this, the entries in the
mcount_loc section will be ignored if they are zero or match the
kaslr_offset() value.
Before:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
551
After:
~# grep __ftrace_invalid_address___ /sys/kernel/tracing/available_filter_functions | wc -l
0
Cc: bpf <bpf@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Martin Kelly <martin.kelly@crowdstrike.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Link: https://lore.kernel.org/20250218200022.883095980@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Merge tag 'v6.14-rc3' into x86/core, to pick up fixes
Pick up upstream x86 fixes before applying new patches.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hrtimer_setup() takes the callback function pointer as argument and
initializes the timer completely.
Replace hrtimer_init() and the open coded initialization of
hrtimer::function with the new setup mechanism.
Patch was created by using Coccinelle.
Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/all/ff8e6e11df5f928b2b97619ac847b4fa045376a1.1738746821.git.namcao@linutronix.de
The pages_touched field represents the number of subbuffers in the ring
buffer that have content that can be read. This is used in accounting of
"dirty_pages" and "buffer_percent" to allow the user to wait for the
buffer to be filled to a certain amount before it reads the buffer in
blocking mode.
The persistent buffer never updated this value so it was set to zero, and
this accounting would take it as it had no content. This would cause user
space to wait for content even though there's enough content in the ring
buffer that satisfies the buffer_percent.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20250214123512.0631436e@gandalf.local.home
Fixes: 5f3b6e839f ("ring-buffer: Validate boot range memory events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When trying to mmap a trace instance buffer that is attached to
reserve_mem, it would crash:
BUG: unable to handle page fault for address: ffffe97bd00025c8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 2862f3067 P4D 2862f3067 PUD 0
Oops: Oops: 0000 [#1] PREEMPT_RT SMP PTI
CPU: 4 UID: 0 PID: 981 Comm: mmap-rb Not tainted 6.14.0-rc2-test-00003-g7f1a5e3fbf9e-dirty #233
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:validate_page_before_insert+0x5/0xb0
Code: e2 01 89 d0 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 <48> 8b 46 08 a8 01 75 67 66 90 48 89 f0 8b 50 34 85 d2 74 76 48 89
RSP: 0018:ffffb148c2f3f968 EFLAGS: 00010246
RAX: ffff9fa5d3322000 RBX: ffff9fa5ccff9c08 RCX: 00000000b879ed29
RDX: ffffe97bd00025c0 RSI: ffffe97bd00025c0 RDI: ffff9fa5ccff9c08
RBP: ffffb148c2f3f9f0 R08: 0000000000000004 R09: 0000000000000004
R10: 0000000000000000 R11: 0000000000000200 R12: 0000000000000000
R13: 00007f16a18d5000 R14: ffff9fa5c48db6a8 R15: 0000000000000000
FS: 00007f16a1b54740(0000) GS:ffff9fa73df00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffe97bd00025c8 CR3: 00000001048c6006 CR4: 0000000000172ef0
Call Trace:
<TASK>
? __die_body.cold+0x19/0x1f
? __die+0x2e/0x40
? page_fault_oops+0x157/0x2b0
? search_module_extables+0x53/0x80
? validate_page_before_insert+0x5/0xb0
? kernelmode_fixup_or_oops.isra.0+0x5f/0x70
? __bad_area_nosemaphore+0x16e/0x1b0
? bad_area_nosemaphore+0x16/0x20
? do_kern_addr_fault+0x77/0x90
? exc_page_fault+0x22b/0x230
? asm_exc_page_fault+0x2b/0x30
? validate_page_before_insert+0x5/0xb0
? vm_insert_pages+0x151/0x400
__rb_map_vma+0x21f/0x3f0
ring_buffer_map+0x21b/0x2f0
tracing_buffers_mmap+0x70/0xd0
__mmap_region+0x6f0/0xbd0
mmap_region+0x7f/0x130
do_mmap+0x475/0x610
vm_mmap_pgoff+0xf2/0x1d0
ksys_mmap_pgoff+0x166/0x200
__x64_sys_mmap+0x37/0x50
x64_sys_call+0x1670/0x1d70
do_syscall_64+0xbb/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The reason was that the code that maps the ring buffer pages to user space
has:
page = virt_to_page((void *)cpu_buffer->subbuf_ids[s]);
And uses that in:
vm_insert_pages(vma, vma->vm_start, pages, &nr_pages);
But virt_to_page() does not work with vmap()'d memory which is what the
persistent ring buffer has. It is rather trivial to allow this, but for
now just disable mmap() of instances that have their ring buffer from the
reserve_mem option.
If an mmap() is performed on a persistent buffer it will return -ENODEV
just like it would if the .mmap field wasn't defined in the
file_operations structure.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20250214115547.0d7287d3@gandalf.local.home
Fixes: 9b7bdf6f6e ("tracing: Have trace_printk not use binary prints if boot buffer")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The meta data for a mapped ring buffer contains an array of indexes of all
the subbuffers. The first entry is the reader page, and the rest of the
entries lay out the order of the subbuffers in how the ring buffer link
list is to be created.
The validator currently makes sure that all the entries are within the
range of 0 and nr_subbufs. But it does not check if there are any
duplicates.
While working on the ring buffer, I corrupted this array, where I added
duplicates. The validator did not catch it and created the ring buffer
link list on top of it. Luckily, the corruption was only that the reader
page was also in the writer path and only presented corrupted data but did
not crash the kernel. But if there were duplicates in the writer side,
then it could corrupt the ring buffer link list and cause a crash.
Create a bitmask array with the size of the number of subbuffers. Then
clear it. When walking through the subbuf array checking to see if the
entries are within the range, test if its bit is already set in the
subbuf_mask. If it is, then there is duplicates and fail the validation.
If not, set the corresponding bit and continue.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20250214102820.7509ddea@gandalf.local.home
Fixes: c76883f18e ("ring-buffer: Add test if range of boot buffer is valid")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Currently if __tracing_resize_ring_buffer() returns an error, the
tracing_resize_ringbuffer() returns -ENOMEM. But it may not be a memory
issue that caused the function to fail. If the ring buffer is memory
mapped, then the resizing of the ring buffer will be disabled. But if the
user tries to resize the buffer, it will get an -ENOMEM returned, which is
confusing because there is plenty of memory. The actual error returned was
-EBUSY, which would make much more sense to the user.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20250213134132.7e4505d7@gandalf.local.home
Fixes: 117c39200d ("ring-buffer: Introducing ring-buffer mapping functions")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Memory mapping the tracing ring buffer will disable resizing the buffer.
But if there's an error in the memory mapping like an invalid parameter,
the function exits out without re-enabling the resizing of the ring
buffer, preventing the ring buffer from being resized after that.
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/20250213131957.530ec3c5@gandalf.local.home
Fixes: 117c39200d ("ring-buffer: Introducing ring-buffer mapping functions")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Pretty much every caller of is_endbr() actually wants to test something at an
address and ends up doing get_kernel_nofault(). Fold the lot into a more
convenient helper.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20250207122546.181367417@infradead.org
The code was restructured where the function graph notrace code, that
would not trace a function and all its children is done by setting a
NOTRACE flag when the function that is not to be traced is hit.
There's a TRACE_GRAPH_NOTRACE_BIT which defines the bit in the flags and a
TRACE_GRAPH_NOTRACE which is the mask with that bit set. But the
restructuring used TRACE_GRAPH_NOTRACE_BIT when it should have used
TRACE_GRAPH_NOTRACE.
For example:
# cd /sys/kernel/tracing
# echo set_track_prepare stack_trace_save > set_graph_notrace
# echo function_graph > current_tracer
# cat trace
[..]
0) | __slab_free() {
0) | free_to_partial_list() {
0) | arch_stack_walk() {
0) | __unwind_start() {
0) 0.501 us | get_stack_info();
Where a non filter trace looks like:
# echo > set_graph_notrace
# cat trace
0) | free_to_partial_list() {
0) | set_track_prepare() {
0) | stack_trace_save() {
0) | arch_stack_walk() {
0) | __unwind_start() {
Where the filter should look like:
# cat trace
0) | free_to_partial_list() {
0) | _raw_spin_lock_irqsave() {
0) 0.350 us | preempt_count_add();
0) 0.351 us | do_raw_spin_lock();
0) 2.440 us | }
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250208001511.535be150@batman.local.home
Fixes: b84214890a ("function_graph: Move graph notrace bit to shadow stack global var")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add the const qualifier to all the ctl_tables in the tree except for
watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls,
loadpin_sysctl_table and the ones calling register_net_sysctl (./net,
drivers/inifiniband dirs). These are special cases as they use a
registration function with a non-const qualified ctl_table argument or
modify the arrays before passing them on to the registration function.
Constifying ctl_table structs will prevent the modification of
proc_handler function pointers as the arrays would reside in .rodata.
This is made possible after commit 78eb4ea25c ("sysctl: treewide:
constify the ctl_table argument of proc_handlers") constified all the
proc_handlers.
Created this by running an spatch followed by a sed command:
Spatch:
virtual patch
@
depends on !(file in "net")
disable optional_qualifier
@
identifier table_name != {
watchdog_hardlockup_sysctl,
iwcm_ctl_table,
ucma_ctl_table,
memory_allocation_profiling_sysctls,
loadpin_sysctl_table
};
@@
+ const
struct ctl_table table_name [] = { ... };
sed:
sed --in-place \
-e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \
kernel/utsname_sysctl.c
Reviewed-by: Song Liu <song@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI
Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Acked-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
- Add a test suite to test the tool
Add a small test suite that can be used to test rtla's basic features to
at least have something to test when applying changes.
- Automate manual steps in monitor creation
While creating a new monitor in RV, besides generating code from dot2k,
there are a few manual steps which can be tedious and error prone, like
adding the tracepoints, makefile lines and kconfig, or selecting events
that start the monitor in the initial state.
Updates were made to try and automate as much as possible among those steps to
make creating a new RV monitor much quicker. It is still requires to
select proper tracepoints, this step is harder to automate in a general
way and, in several cases, would still need user intervention.
- Have rtla timerlat hist and top set OSNOISE_WORKLOAD flag
Have both rtla-timerlat-hist and rtla-timerlat-top set OSNOISE_WORKLOAD to
the proper value ("on" when running with -k, "off" when running with -u)
every time the option is available instead of setting it only when running
with -u.
This prevents rtla timerlat -k from giving no results when
NO_OSNOISE_WORKLOAD is set, either manually or by an abnormally exited earlier
run of rtla timerlat -u.
- Stop rtla timerlat on signal properly when overloaded
There is an issue where if rtla is run on machines with a high number of
CPUs (100+), timerlat can generate more samples than rtla is able to process
via tracefs_iterate_raw_events. This is especially common when the interval
is set to 100us (rteval and cyclictest default) as opposed to the rtla
default of 1000us, but also happens with the rtla default.
Currently, this leads to rtla hanging and having to be terminated with
SIGTERM. SIGINT setting stop_tracing is not enough, since more and more
events are coming and tracefs_iterate_raw_events never exits.
To fix this: Stop the timerlat tracer on SIGINT/SIGALRM to ensure no more
events are generated when rtla is supposed to exit.
Also on receiving SIGINT/SIGALRM twice, abort iteration immediately with
tracefs_iterate_stop, making rtla exit right away instead of waiting for all
events to be processed.
- Account for missed events
Due to tracefs buffer overflow, it can happen that rtla misses events,
making the tracing results inaccurate.
Count both the number of missed events and the total number of processed
events, and display missed events as well as their percentage. The numbers
are displayed for both osnoise and timerlat, even though for the earlier,
missed events are generally not expected.
For hist, the number is displayed at the end of the run; for top, it is
displayed on each printing of the top table.
- Changes to make osnoise more robust
There was a dependency in the code that the first field of the
osnoise_tool structure was the trace field. If that that ever changed,
then the code work break. Change the code to encapsulate this dependency
where the code that uses the structure does not have this dependency.
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Merge tag 'trace-tools-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull rv and tools/rtla updates from Steven Rostedt:
- Add a test suite to test the tool
Add a small test suite that can be used to test rtla's basic features
to at least have something to test when applying changes.
- Automate manual steps in monitor creation
While creating a new monitor in RV, besides generating code from
dot2k, there are a few manual steps which can be tedious and error
prone, like adding the tracepoints, makefile lines and kconfig, or
selecting events that start the monitor in the initial state.
Updates were made to try and automate as much as possible among those
steps to make creating a new RV monitor much quicker. It is still
requires to select proper tracepoints, this step is harder to
automate in a general way and, in several cases, would still need
user intervention.
- Have rtla timerlat hist and top set OSNOISE_WORKLOAD flag
Have both rtla-timerlat-hist and rtla-timerlat-top set
OSNOISE_WORKLOAD to the proper value ("on" when running with -k,
"off" when running with -u) every time the option is available
instead of setting it only when running with -u.
This prevents rtla timerlat -k from giving no results when
NO_OSNOISE_WORKLOAD is set, either manually or by an abnormally
exited earlier run of rtla timerlat -u.
- Stop rtla timerlat on signal properly when overloaded
There is an issue where if rtla is run on machines with a high number
of CPUs (100+), timerlat can generate more samples than rtla is able
to process via tracefs_iterate_raw_events. This is especially common
when the interval is set to 100us (rteval and cyclictest default) as
opposed to the rtla default of 1000us, but also happens with the rtla
default.
Currently, this leads to rtla hanging and having to be terminated
with SIGTERM. SIGINT setting stop_tracing is not enough, since more
and more events are coming and tracefs_iterate_raw_events never
exits.
To fix this: Stop the timerlat tracer on SIGINT/SIGALRM to ensure no
more events are generated when rtla is supposed to exit.
Also on receiving SIGINT/SIGALRM twice, abort iteration immediately
with tracefs_iterate_stop, making rtla exit right away instead of
waiting for all events to be processed.
- Account for missed events
Due to tracefs buffer overflow, it can happen that rtla misses
events, making the tracing results inaccurate.
Count both the number of missed events and the total number of
processed events, and display missed events as well as their
percentage. The numbers are displayed for both osnoise and timerlat,
even though for the earlier, missed events are generally not
expected.
For hist, the number is displayed at the end of the run; for top, it
is displayed on each printing of the top table.
- Changes to make osnoise more robust
There was a dependency in the code that the first field of the
osnoise_tool structure was the trace field. If that that ever
changed, then the code work break. Change the code to encapsulate
this dependency where the code that uses the structure does not have
this dependency.
* tag 'trace-tools-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (22 commits)
rtla: Report missed event count
rtla: Add function to report missed events
rtla: Count all processed events
rtla: Count missed trace events
tools/rtla: Add osnoise_trace_is_off()
rtla/timerlat_top: Set OSNOISE_WORKLOAD for kernel threads
rtla/timerlat_hist: Set OSNOISE_WORKLOAD for kernel threads
rtla/osnoise: Distinguish missing workload option
rtla/timerlat_top: Abort event processing on second signal
rtla/timerlat_hist: Abort event processing on second signal
rtla/timerlat_top: Stop timerlat tracer on signal
rtla/timerlat_hist: Stop timerlat tracer on signal
rtla: Add trace_instance_stop
tools/rtla: Add basic test suite
verification/dot2k: Implement event type detection
verification/dot2k: Auto patch current kernel source
verification/dot2k: Simplify manual steps in monitor creation
rv: Simplify manual steps in monitor creation
verification/dot2k: Add support for name and description options
verification/dot2k: More robust template variables
...
- Reset idle tasks on reset for runtime verifier
When the runtime verifier is reset, it resets the task's data that is being
monitored. But it only iterates for_each_process() which does not include
the idle tasks. As the idle tasks can be monitored, they need to be reset
as well.
- Fix the enabling and disabling of tracepoints in osnoise
If timerlat is enabled and the WORKLOAD flag is not set, then the osnoise
tracer will enable the migrate task tracepoint to monitor it for its own
workload. The test to enable the tracepoint is done against user space
modifiable parameters. On disabling of the tracer, those same parameters
are used to determine if the tracepoint should be disabled. The problem is
if user space were to modify the parameters after it enables the tracer
then it may not disable the tracepoint.
Instead, a static variable is used to keep track if the tracepoint was
enabled or not. Then when the tracer shuts down, it will use this variable
to decide to disable the tracepoint or not, instead of looking at the user
space parameters.
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Merge tag 'trace-rv-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull runtime verifier and osnoise fixes from Steven Rostedt:
- Reset idle tasks on reset for runtime verifier
When the runtime verifier is reset, it resets the task's data that is
being monitored. But it only iterates for_each_process() which does
not include the idle tasks. As the idle tasks can be monitored, they
need to be reset as well.
- Fix the enabling and disabling of tracepoints in osnoise
If timerlat is enabled and the WORKLOAD flag is not set, then the
osnoise tracer will enable the migrate task tracepoint to monitor it
for its own workload. The test to enable the tracepoint is done
against user space modifiable parameters. On disabling of the tracer,
those same parameters are used to determine if the tracepoint should
be disabled. The problem is if user space were to modify the
parameters after it enables the tracer then it may not disable the
tracepoint.
Instead, a static variable is used to keep track if the tracepoint
was enabled or not. Then when the tracer shuts down, it will use this
variable to decide to disable the tracepoint or not, instead of
looking at the user space parameters.
* tag 'trace-rv-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/osnoise: Fix resetting of tracepoints
rv: Reset per-task monitors also for idle tasks
If a timerlat tracer is started with the osnoise option OSNOISE_WORKLOAD
disabled, but then that option is enabled and timerlat is removed, the
tracepoints that were enabled on timerlat registration do not get
disabled. If the option is disabled again and timelat is started, then it
triggers a warning in the tracepoint code due to registering the
tracepoint again without ever disabling it.
Do not use the same user space defined options to know to disable the
tracepoints when timerlat is removed. Instead, set a global flag when it
is enabled and use that flag to know to disable the events.
~# echo NO_OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options
~# echo timerlat > /sys/kernel/tracing/current_tracer
~# echo OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options
~# echo nop > /sys/kernel/tracing/current_tracer
~# echo NO_OSNOISE_WORKLOAD > /sys/kernel/tracing/osnoise/options
~# echo timerlat > /sys/kernel/tracing/current_tracer
Triggers:
------------[ cut here ]------------
WARNING: CPU: 6 PID: 1337 at kernel/tracepoint.c:294 tracepoint_add_func+0x3b6/0x3f0
Modules linked in:
CPU: 6 UID: 0 PID: 1337 Comm: rtla Not tainted 6.13.0-rc4-test-00018-ga867c441128e-dirty #73
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:tracepoint_add_func+0x3b6/0x3f0
Code: 48 8b 53 28 48 8b 73 20 4c 89 04 24 e8 23 59 11 00 4c 8b 04 24 e9 36 fe ff ff 0f 0b b8 ea ff ff ff 45 84 e4 0f 84 68 fe ff ff <0f> 0b e9 61 fe ff ff 48 8b 7b 18 48 85 ff 0f 84 4f ff ff ff 49 8b
RSP: 0018:ffffb9b003a87ca0 EFLAGS: 00010202
RAX: 00000000ffffffef RBX: ffffffff92f30860 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff9bf59e91ccd0 RDI: ffffffff913b6410
RBP: 000000000000000a R08: 00000000000005c7 R09: 0000000000000002
R10: ffffb9b003a87ce0 R11: 0000000000000002 R12: 0000000000000001
R13: ffffb9b003a87ce0 R14: ffffffffffffffef R15: 0000000000000008
FS: 00007fce81209240(0000) GS:ffff9bf6fdd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e99b728000 CR3: 00000001277c0002 CR4: 0000000000172ef0
Call Trace:
<TASK>
? __warn.cold+0xb7/0x14d
? tracepoint_add_func+0x3b6/0x3f0
? report_bug+0xea/0x170
? handle_bug+0x58/0x90
? exc_invalid_op+0x17/0x70
? asm_exc_invalid_op+0x1a/0x20
? __pfx_trace_sched_migrate_callback+0x10/0x10
? tracepoint_add_func+0x3b6/0x3f0
? __pfx_trace_sched_migrate_callback+0x10/0x10
? __pfx_trace_sched_migrate_callback+0x10/0x10
tracepoint_probe_register+0x78/0xb0
? __pfx_trace_sched_migrate_callback+0x10/0x10
osnoise_workload_start+0x2b5/0x370
timerlat_tracer_init+0x76/0x1b0
tracing_set_tracer+0x244/0x400
tracing_set_trace_write+0xa0/0xe0
vfs_write+0xfc/0x570
? do_sys_openat2+0x9c/0xe0
ksys_write+0x72/0xf0
do_syscall_64+0x79/0x1c0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tomas Glozar <tglozar@redhat.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Link: https://lore.kernel.org/20250123204159.4450c88e@gandalf.local.home
Fixes: e88ed227f6 ("tracing/timerlat: Add user-space interface")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Have emulating atomic64 use arch_spin_locks instead of raw_spin_locks
The tracing ring buffer events have a small timestamp that holds the
delta between itself and the event before it. But this can be tricky
to update when interrupts come in. It originally just set the deltas
to zero for events that interrupted the adding of another event which
made all the events in the interrupt have the same timestamp as the
event it interrupted. This was not suitable for many tools, so it
was eventually fixed. But that fix required adding an atomic64 cmpxchg
on the timestamp in cases where an event was added while another
event was in the process of being added.
Originally, for 32 bit architectures, the manipulation of the 64 bit
timestamp was done by a structure that held multiple 32bit words to hold
parts of the timestamp and a counter. But as updates to the ring buffer
were done, maintaining this became too complex and was replaced by the
atomic64 generic operations which are now used by both 64bit and 32bit
architectures. Shortly after that, it was reported that riscv32 and
other 32 bit architectures that just used the generic atomic64 were
locking up. This was because the generic atomic64 operations defined in
lib/atomic64.c uses a raw_spin_lock() to emulate an atomic64 operation.
The problem here was that raw_spin_lock() can also be traced by the
function tracer (which is commonly used for debugging raw spin locks).
Since the function tracer uses the tracing ring buffer, which now is being
traced internally, this was triggering a recursion and setting off a
warning that the spin locks were recusing.
There's no reason for the code that emulates atomic64 operations to be
using raw_spin_locks which have a lot of debugging infrastructure attached
to them (depending on the config options). Instead it should be using
the arch_spin_lock() which does not have any infrastructure attached to
them and is used by low level infrastructure like RCU locks, lockdep
and of course tracing. Using arch_spin_lock()s fixes this issue.
- Do not trace in NMI if the architecture uses emulated atomic64 operations
Another issue with using the emulated atomic64 operations that uses
spin locks to emulate the atomic64 operations is that they cannot be
used in NMI context. As an NMI can trigger while holding the atomic64
spin locks it can try to take the same lock and cause a deadlock.
Have the ring buffer fail recording events if in NMI context and the
architecture uses the emulated atomic64 operations.
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Merge tag 'trace-ringbuffer-v6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull trace fing buffer fix from Steven Rostedt:
"Fix atomic64 operations on some architectures for the tracing ring
buffer:
- Have emulating atomic64 use arch_spin_locks instead of
raw_spin_locks
The tracing ring buffer events have a small timestamp that holds
the delta between itself and the event before it. But this can be
tricky to update when interrupts come in. It originally just set
the deltas to zero for events that interrupted the adding of
another event which made all the events in the interrupt have the
same timestamp as the event it interrupted. This was not suitable
for many tools, so it was eventually fixed. But that fix required
adding an atomic64 cmpxchg on the timestamp in cases where an event
was added while another event was in the process of being added.
Originally, for 32 bit architectures, the manipulation of the 64
bit timestamp was done by a structure that held multiple 32bit
words to hold parts of the timestamp and a counter. But as updates
to the ring buffer were done, maintaining this became too complex
and was replaced by the atomic64 generic operations which are now
used by both 64bit and 32bit architectures. Shortly after that, it
was reported that riscv32 and other 32 bit architectures that just
used the generic atomic64 were locking up. This was because the
generic atomic64 operations defined in lib/atomic64.c uses a
raw_spin_lock() to emulate an atomic64 operation. The problem here
was that raw_spin_lock() can also be traced by the function tracer
(which is commonly used for debugging raw spin locks). Since the
function tracer uses the tracing ring buffer, which now is being
traced internally, this was triggering a recursion and setting off
a warning that the spin locks were recusing.
There's no reason for the code that emulates atomic64 operations to
be using raw_spin_locks which have a lot of debugging
infrastructure attached to them (depending on the config options).
Instead it should be using the arch_spin_lock() which does not have
any infrastructure attached to them and is used by low level
infrastructure like RCU locks, lockdep and of course tracing. Using
arch_spin_lock()s fixes this issue.
- Do not trace in NMI if the architecture uses emulated atomic64
operations
Another issue with using the emulated atomic64 operations that uses
spin locks to emulate the atomic64 operations is that they cannot
be used in NMI context. As an NMI can trigger while holding the
atomic64 spin locks it can try to take the same lock and cause a
deadlock.
Have the ring buffer fail recording events if in NMI context and
the architecture uses the emulated atomic64 operations"
* tag 'trace-ringbuffer-v6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
atomic64: Use arch_spin_locks instead of raw_spin_locks
ring-buffer: Do not allow events in NMI with generic atomic64 cmpxchg()
The calltime and rettime were used by the function graph tracer to
calculate the timings of functions where it traced their entry and exit.
The calltime and rettime were stored in the generic structures that
were used for the mechanisms to add an entry and exit callback.
Now that function graph infrastructure is used by other subsystems than
just the tracer, the calltime and rettime are not needed for them.
Remove the calltime and rettime from the generic fgraph infrastructure
and have the callers that require them handle them.
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Merge tag 'ftrace-v6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull fgraph updates from Steven Rostedt:
"Remove calltime and rettime from fgraph infrastructure
The calltime and rettime were used by the function graph tracer to
calculate the timings of functions where it traced their entry and
exit. The calltime and rettime were stored in the generic structures
that were used for the mechanisms to add an entry and exit callback.
Now that function graph infrastructure is used by other subsystems
than just the tracer, the calltime and rettime are not needed for
them. Remove the calltime and rettime from the generic fgraph
infrastructure and have the callers that require them handle them"
* tag 'ftrace-v6.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
fgraph: Remove calltime and rettime from generic operations
- Cleanup with guard() and free() helpers
There were several places in the code that had a lot of "goto out" in the
error paths to either unlock a lock or free some memory that was
allocated. But this is error prone. Convert the code over to use the
guard() and free() helpers that let the compiler unlock locks or free
memory when the function exits.
- Update the Rust tracepoint code to use the C code too
There was some duplication of the tracepoint code for Rust that did the
same logic as the C code. Add a helper that makes it possible for both
algorithms to use the same logic in one place.
- Add poll to trace event hist files
It is useful to know when an event is triggered, or even with some
filtering. Since hist files of events get updated when active and the
event is triggered, allow applications to poll the hist file and wake up
when an event is triggered. This will let the application know that the
event it is waiting for happened.
- Add :mod: command to enable events for current or future modules
The function tracer already has a way to enable functions to be traced in
modules by writing ":mod:<module>" into set_ftrace_filter. That will
enable either all the functions for the module if it is loaded, or if it
is not, it will cache that command, and when the module is loaded that
matches <module>, its functions will be enabled. This also allows init
functions to be traced. But currently events do not have that feature.
Add the command where if ':mod:<module>' is written into set_event, then
either all the modules events are enabled if it is loaded, or cache it so
that the module's events are enabled when it is loaded. This also works
from the kernel command line, where "trace_event=:mod:<module>", when the
module is loaded at boot up, its events will be enabled then.
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Merge tag 'trace-v6.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- Cleanup with guard() and free() helpers
There were several places in the code that had a lot of "goto out" in
the error paths to either unlock a lock or free some memory that was
allocated. But this is error prone. Convert the code over to use the
guard() and free() helpers that let the compiler unlock locks or free
memory when the function exits.
- Update the Rust tracepoint code to use the C code too
There was some duplication of the tracepoint code for Rust that did
the same logic as the C code. Add a helper that makes it possible for
both algorithms to use the same logic in one place.
- Add poll to trace event hist files
It is useful to know when an event is triggered, or even with some
filtering. Since hist files of events get updated when active and the
event is triggered, allow applications to poll the hist file and wake
up when an event is triggered. This will let the application know
that the event it is waiting for happened.
- Add :mod: command to enable events for current or future modules
The function tracer already has a way to enable functions to be
traced in modules by writing ":mod:<module>" into set_ftrace_filter.
That will enable either all the functions for the module if it is
loaded, or if it is not, it will cache that command, and when the
module is loaded that matches <module>, its functions will be
enabled. This also allows init functions to be traced. But currently
events do not have that feature.
Add the command where if ':mod:<module>' is written into set_event,
then either all the modules events are enabled if it is loaded, or
cache it so that the module's events are enabled when it is loaded.
This also works from the kernel command line, where
"trace_event=:mod:<module>", when the module is loaded at boot up,
its events will be enabled then.
* tag 'trace-v6.14-3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits)
tracing: Fix output of set_event for some cached module events
tracing: Fix allocation of printing set_event file content
tracing: Rename update_cache() to update_mod_cache()
tracing: Fix #if CONFIG_MODULES to #ifdef CONFIG_MODULES
selftests/ftrace: Add test that tests event :mod: commands
tracing: Cache ":mod:" events for modules not loaded yet
tracing: Add :mod: command to enabled module events
selftests/tracing: Add hist poll() support test
tracing/hist: Support POLLPRI event for poll on histogram
tracing/hist: Add poll(POLLIN) support on hist file
tracing: Fix using ret variable in tracing_set_tracer()
tracepoint: Reduce duplication of __DO_TRACE_CALL
tracing/string: Create and use __free(argv_free) in trace_dynevent.c
tracing: Switch trace_stat.c code over to use guard()
tracing: Switch trace_stack.c code over to use guard()
tracing: Switch trace_osnoise.c code over to use guard() and __free()
tracing: Switch trace_events_synth.c code over to use guard()
tracing: Switch trace_events_filter.c code over to use guard()
tracing: Switch trace_events_trigger.c code over to use guard()
tracing: Switch trace_events_hist.c code over to use guard()
...
- kprobes: Cleanups using guard() and __free(): Use cleanup.h macros
to cleanup code and remove all gotos from kprobes code. This work
includes below changes.
. kprobes: Adopt guard() and scoped_guard()
. jump_label: Define guard() for jump_label_lock
. kprobes: Use guard() for external locks
. kprobes: Use guard for rcu_read_lock
. kprobes: Remove unneeded goto
. kprobes: Remove remaining gotos
- tracing/probes: Also cleanups tracing/*probe events code with guard()
and __free(). These patches are just to simplify the parser codes.
This work includes below changes.
. tracing/kprobe: Adopt guard() and scoped_guard()
. tracing/uprobe: Adopt guard() and scoped_guard()
. tracing/eprobe: Adopt guard() and scoped_guard()
. tracing: Use __free() in trace_probe for cleanup
. tracing: Use __free() for kprobe events to cleanup
. tracing/kprobes: Simplify __trace_kprobe_create() by removing gotos
- kprobes: Reduce preempt disable scope in check_kprobe_access_safe()
This reduces preempt disable time only when getting the module
refcount in check_kprobe_access_safe(). Previously it disabled
preempt needlessly for other checks including
jump_label_text_reserved(), but it took long time because of
the linear search.
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Merge tag 'probes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes updates from Masami Hiramatsu:
- kprobes: Cleanups using guard() and __free(): Use cleanup.h macros to
cleanup code and remove all gotos from kprobes code.
- tracing/probes: Also cleanups tracing/*probe events code with guard()
and __free(). These patches are just to simplify the parser codes.
- kprobes: Reduce preempt disable scope in check_kprobe_access_safe()
This reduces preempt disable time to only when getting the module
refcount in check_kprobe_access_safe().
Previously it disabled preempt needlessly for other checks including
jump_label_text_reserved(), which took a long time because of the
linear search.
* tag 'probes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/kprobes: Simplify __trace_kprobe_create() by removing gotos
tracing: Use __free() for kprobe events to cleanup
tracing: Use __free() in trace_probe for cleanup
kprobes: Remove remaining gotos
kprobes: Remove unneeded goto
kprobes: Use guard for rcu_read_lock
kprobes: Use guard() for external locks
jump_label: Define guard() for jump_label_lock
tracing/eprobe: Adopt guard() and scoped_guard()
tracing/uprobe: Adopt guard() and scoped_guard()
tracing/kprobe: Adopt guard() and scoped_guard()
kprobes: Adopt guard() and scoped_guard()
kprobes: Reduce preempt disable scope in check_kprobe_access_safe()
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Merge tag 'bpf-next-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
"A smaller than usual release cycle.
The main changes are:
- Prepare selftest to run with GCC-BPF backend (Ihor Solodrai)
In addition to LLVM-BPF runs the BPF CI now runs GCC-BPF in compile
only mode. Half of the tests are failing, since support for
btf_decl_tag is still WIP, but this is a great milestone.
- Convert various samples/bpf to selftests/bpf/test_progs format
(Alexis Lothoré and Bastien Curutchet)
- Teach verifier to recognize that array lookup with constant
in-range index will always succeed (Daniel Xu)
- Cleanup migrate disable scope in BPF maps (Hou Tao)
- Fix bpf_timer destroy path in PREEMPT_RT (Hou Tao)
- Always use bpf_mem_alloc in bpf_local_storage in PREEMPT_RT (Martin
KaFai Lau)
- Refactor verifier lock support (Kumar Kartikeya Dwivedi)
This is a prerequisite for upcoming resilient spin lock.
- Remove excessive 'may_goto +0' instructions in the verifier that
LLVM leaves when unrolls the loops (Yonghong Song)
- Remove unhelpful bpf_probe_write_user() warning message (Marco
Elver)
- Add fd_array_cnt attribute for prog_load command (Anton Protopopov)
This is a prerequisite for upcoming support for static_branch"
* tag 'bpf-next-6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (125 commits)
selftests/bpf: Add some tests related to 'may_goto 0' insns
bpf: Remove 'may_goto 0' instruction in opt_remove_nops()
bpf: Allow 'may_goto 0' instruction in verifier
selftests/bpf: Add test case for the freeing of bpf_timer
bpf: Cancel the running bpf_timer through kworker for PREEMPT_RT
bpf: Free element after unlock in __htab_map_lookup_and_delete_elem()
bpf: Bail out early in __htab_map_lookup_and_delete_elem()
bpf: Free special fields after unlock in htab_lru_map_delete_node()
tools: Sync if_xdp.h uapi tooling header
libbpf: Work around kernel inconsistently stripping '.llvm.' suffix
bpf: selftests: verifier: Add nullness elision tests
bpf: verifier: Support eliding map lookup nullness
bpf: verifier: Refactor helper access type tracking
bpf: tcp: Mark bpf_load_hdr_opt() arg2 as read-write
bpf: verifier: Add missing newline on verbose() call
selftests/bpf: Add distilled BTF test about marking BTF_IS_EMBEDDED
libbpf: Fix incorrect traversal end type ID when marking BTF_IS_EMBEDDED
libbpf: Fix return zero when elf_begin failed
selftests/bpf: Fix btf leak on new btf alloc failure in btf_distill test
veristat: Load struct_ops programs only once
...
The function graph infrastructure is now generic so that kretprobes,
fprobes and BPF can use it. But there is still some leftover logic that
only the function graph tracer itself uses. This is the calculation of the
calltime and return time of the functions. The calculation of the calltime
has been moved into the function graph tracer and those users that need it
so that it doesn't cause overhead to the other users. But the return
function timestamp was still called.
Instead of just moving the taking of the timestamp into the function graph
trace remove the calltime and rettime completely from the ftrace_graph_ret
structure. Instead, move it into the function graph return entry event
structure and this also moves all the calltime and rettime logic out of
the generic fgraph.c code and into the tracing code that uses it.
This has been reported to decrease the overhead by ~27%.
Link: https://lore.kernel.org/all/Z3aSuql3fnXMVMoM@krava/
Link: https://lore.kernel.org/all/173665959558.1629214.16724136597211810729.stgit@devnote2/
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250121194436.15bdf71a@gandalf.local.home
Reported-by: Jiri Olsa <olsajiri@gmail.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Have fprobes built on top of function graph infrastructure
The fprobe logic is an optimized kprobe that uses ftrace to attach to
functions when a probe is needed at the start or end of the function. The
fprobe and kretprobe logic implements a similar method as the function
graph tracer to trace the end of the function. That is to hijack the
return address and jump to a trampoline to do the trace when the function
exits. To do this, a shadow stack needs to be created to store the
original return address. Fprobes and function graph do this slightly
differently. Fprobes (and kretprobes) has slots per callsite that are
reserved to save the return address. This is fine when just a few points
are traced. But users of fprobes, such as BPF programs, are starting to add
many more locations, and this method does not scale.
The function graph tracer was created to trace all functions in the
kernel. In order to do this, when function graph tracing is started, every
task gets its own shadow stack to hold the return address that is going to
be traced. The function graph tracer has been updated to allow multiple
users to use its infrastructure. Now have fprobes be one of those users.
This will also allow for the fprobe and kretprobe methods to trace the
return address to become obsolete. With new technologies like CFI that
need to know about these methods of hijacking the return address, going
toward a solution that has only one method of doing this will make the
kernel less complex.
- Cleanup with guard() and free() helpers
There were several places in the code that had a lot of "goto out" in the
error paths to either unlock a lock or free some memory that was
allocated. But this is error prone. Convert the code over to use the
guard() and free() helpers that let the compiler unlock locks or free
memory when the function exits.
- Remove disabling of interrupts in the function graph tracer
When function graph tracer was first introduced, it could race with
interrupts and NMIs. To prevent that race, it would disable interrupts and
not trace NMIs. But the code has changed to allow NMIs and also
interrupts. This change was done a long time ago, but the disabling of
interrupts was never removed. Remove the disabling of interrupts in the
function graph tracer is it is not needed. This greatly improves its
performance.
- Allow the :mod: command to enable tracing module functions on the kernel
command line.
The function tracer already has a way to enable functions to be traced in
modules by writing ":mod:<module>" into set_ftrace_filter. That will
enable either all the functions for the module if it is loaded, or if it
is not, it will cache that command, and when the module is loaded that
matches <module>, its functions will be enabled. This also allows init
functions to be traced. But currently events do not have that feature.
Because enabling function tracing can be done very early at boot up
(before scheduling is enabled), the commands that can be done when
function tracing is started is limited. Having the ":mod:" command to
trace module functions as they are loaded is very useful. Update the
kernel command line function filtering to allow it.
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Merge tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace updates from Steven Rostedt:
- Have fprobes built on top of function graph infrastructure
The fprobe logic is an optimized kprobe that uses ftrace to attach to
functions when a probe is needed at the start or end of the function.
The fprobe and kretprobe logic implements a similar method as the
function graph tracer to trace the end of the function. That is to
hijack the return address and jump to a trampoline to do the trace
when the function exits. To do this, a shadow stack needs to be
created to store the original return address. Fprobes and function
graph do this slightly differently. Fprobes (and kretprobes) has
slots per callsite that are reserved to save the return address. This
is fine when just a few points are traced. But users of fprobes, such
as BPF programs, are starting to add many more locations, and this
method does not scale.
The function graph tracer was created to trace all functions in the
kernel. In order to do this, when function graph tracing is started,
every task gets its own shadow stack to hold the return address that
is going to be traced. The function graph tracer has been updated to
allow multiple users to use its infrastructure. Now have fprobes be
one of those users. This will also allow for the fprobe and kretprobe
methods to trace the return address to become obsolete. With new
technologies like CFI that need to know about these methods of
hijacking the return address, going toward a solution that has only
one method of doing this will make the kernel less complex.
- Cleanup with guard() and free() helpers
There were several places in the code that had a lot of "goto out" in
the error paths to either unlock a lock or free some memory that was
allocated. But this is error prone. Convert the code over to use the
guard() and free() helpers that let the compiler unlock locks or free
memory when the function exits.
- Remove disabling of interrupts in the function graph tracer
When function graph tracer was first introduced, it could race with
interrupts and NMIs. To prevent that race, it would disable
interrupts and not trace NMIs. But the code has changed to allow NMIs
and also interrupts. This change was done a long time ago, but the
disabling of interrupts was never removed. Remove the disabling of
interrupts in the function graph tracer is it is not needed. This
greatly improves its performance.
- Allow the :mod: command to enable tracing module functions on the
kernel command line.
The function tracer already has a way to enable functions to be
traced in modules by writing ":mod:<module>" into set_ftrace_filter.
That will enable either all the functions for the module if it is
loaded, or if it is not, it will cache that command, and when the
module is loaded that matches <module>, its functions will be
enabled. This also allows init functions to be traced. But currently
events do not have that feature.
Because enabling function tracing can be done very early at boot up
(before scheduling is enabled), the commands that can be done when
function tracing is started is limited. Having the ":mod:" command to
trace module functions as they are loaded is very useful. Update the
kernel command line function filtering to allow it.
* tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits)
ftrace: Implement :mod: cache filtering on kernel command line
tracing: Adopt __free() and guard() for trace_fprobe.c
bpf: Use ftrace_get_symaddr() for kprobe_multi probes
ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr
Documentation: probes: Update fprobe on function-graph tracer
selftests/ftrace: Add a test case for repeating register/unregister fprobe
selftests: ftrace: Remove obsolate maxactive syntax check
tracing/fprobe: Remove nr_maxactive from fprobe
fprobe: Add fprobe_header encoding feature
fprobe: Rewrite fprobe on function-graph tracer
s390/tracing: Enable HAVE_FTRACE_GRAPH_FUNC
ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC
bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled
tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
tracing: Add ftrace_fill_perf_regs() for perf event
tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs
fprobe: Use ftrace_regs in fprobe exit handler
fprobe: Use ftrace_regs in fprobe entry handler
fgraph: Pass ftrace_regs to retfunc
fgraph: Replace fgraph_ret_regs with ftrace_regs
...
- Clean up the __rb_map_vma() logic
The logic of __rb_map_vma() has a error check with WARN_ON() that makes
sure that the index does not go past the end of the array of buffers. The
test in the loop pretty much guarantees that it will never happen, but
since the relation of the variables used is a little complex, the
WARN_ON() check was added. It was noticed that the array was dereferenced
before this check and if the logic does break and for some reason the
logic goes past the array, there will be an out of bounds access here.
Move the access to after the WARN_ON().
- Consolidate how the ring buffer is determined to be empty
Currently there's two ways that are used to determine if the ring buffer
is empty. One relies on the status of the commit and reader pages and what
was read, and the other is on what was written vs what was read. By using
the number of entries (written) method, it can be used for reading events
that are out of the kernel's control (what pKVM will use). Move to this
method to make it easier to implement a pKVM ring buffer that the kernel
can read.
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Merge tag 'trace-ringbuffer-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull trace ring-buffer updates from Steven Rostedt:
- Clean up the __rb_map_vma() logic
The logic of __rb_map_vma() has a error check with WARN_ON() that
makes sure that the index does not go past the end of the array of
buffers. The test in the loop pretty much guarantees that it will
never happen, but since the relation of the variables used is a
little complex, the WARN_ON() check was added. It was noticed that
the array was dereferenced before this check and if the logic does
break and for some reason the logic goes past the array, there will
be an out of bounds access here. Move the access to after the
WARN_ON().
- Consolidate how the ring buffer is determined to be empty
Currently there's two ways that are used to determine if the ring
buffer is empty. One relies on the status of the commit and reader
pages and what was read, and the other is on what was written vs what
was read. By using the number of entries (written) method, it can be
used for reading events that are out of the kernel's control (what
pKVM will use). Move to this method to make it easier to implement a
pKVM ring buffer that the kernel can read.
* tag 'trace-ringbuffer-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Make reading page consistent with the code logic
ring-buffer: Check for empty ring-buffer with rb_num_of_entries()
The following works fine:
~# echo ':mod:trace_events_sample' > /sys/kernel/tracing/set_event
~# cat /sys/kernel/tracing/set_event
*:*:mod:trace_events_sample
~#
But if a name is given without a ':' where it can match an event name or
system name, the output of the cached events does not include a new line:
~# echo 'foo_bar:mod:trace_events_sample' > /sys/kernel/tracing/set_event
~# cat /sys/kernel/tracing/set_event
foo_bar:mod:trace_events_sample~#
Add the '\n' to that as well.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250121151336.6c491844@gandalf.local.home
Fixes: b355247df1 ("tracing: Cache ":mod:" events for modules not loaded yet")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The adding of cached events for modules not loaded yet required a
descriptor to separate the iteration of events with the iteration of
cached events for a module. But the allocation used the size of the
pointer and not the size of the contents to allocate its data and caused a
slab-out-of-bounds.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20250121151236.47fcf433@gandalf.local.home
Reported-by: Sasha Levin <sashal@kernel.org>
Closes: https://lore.kernel.org/all/Z4_OHKESRSiJcr-b@lappy/
Fixes: b355247df1 ("tracing: Cache ":mod:" events for modules not loaded yet")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Some architectures can not safely do atomic64 operations in NMI context.
Since the ring buffer relies on atomic64 operations to do its time
keeping, if an event is requested in NMI context, reject it for these
architectures.
Cc: stable@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/20250120235721.407068250@goodmis.org
Fixes: c84897c0ff ("ring-buffer: Remove 32bit timestamp logic")
Closes: https://lore.kernel.org/all/86fb4f86-a0e4-45a2-a2df-3154acc4f086@gaisler.com/
Reported-by: Ludwig Rydberg <ludwig.rydberg@gaisler.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
- Seqlock optimizations that arose in a perf context and were
merged into the perf tree:
- seqlock: Add raw_seqcount_try_begin (Suren Baghdasaryan)
- mm: Convert mm_lock_seq to a proper seqcount ((Suren Baghdasaryan)
- mm: Introduce mmap_lock_speculate_{try_begin|retry} (Suren Baghdasaryan)
- mm/gup: Use raw_seqcount_try_begin() (Peter Zijlstra)
- Core perf enhancements:
- Reduce 'struct page' footprint of perf by mapping pages
in advance (Lorenzo Stoakes)
- Save raw sample data conditionally based on sample type (Yabin Cui)
- Reduce sampling overhead by checking sample_type in
perf_sample_save_callchain() and perf_sample_save_brstack() (Yabin Cui)
- Export perf_exclude_event() (Namhyung Kim)
- Uprobes scalability enhancements: (Andrii Nakryiko)
- Simplify find_active_uprobe_rcu() VMA checks
- Add speculative lockless VMA-to-inode-to-uprobe resolution
- Simplify session consumer tracking
- Decouple return_instance list traversal and freeing
- Ensure return_instance is detached from the list before freeing
- Reuse return_instances between multiple uretprobes within task
- Guard against kmemdup() failing in dup_return_instance()
- AMD core PMU driver enhancements:
- Relax privilege filter restriction on AMD IBS (Namhyung Kim)
- AMD RAPL energy counters support: (Dhananjay Ugwekar)
- Introduce topology_logical_core_id() (K Prateek Nayak)
- Remove the unused get_rapl_pmu_cpumask() function
- Remove the cpu_to_rapl_pmu() function
- Rename rapl_pmu variables
- Make rapl_model struct global
- Add arguments to the init and cleanup functions
- Modify the generic variable names to *_pkg*
- Remove the global variable rapl_msrs
- Move the cntr_mask to rapl_pmus struct
- Add core energy counter support for AMD CPUs
- Intel core PMU driver enhancements:
- Support RDPMC 'metrics clear mode' feature (Kan Liang)
- Clarify adaptive PEBS processing (Kan Liang)
- Factor out functions for PEBS records processing (Kan Liang)
- Simplify the PEBS records processing for adaptive PEBS (Kan Liang)
- Intel uncore driver enhancements: (Kan Liang)
- Convert buggy pmu->func_id use to pmu->registered
- Support more units on Granite Rapids
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull performance events updates from Ingo Molnar:
"Seqlock optimizations that arose in a perf context and were merged
into the perf tree:
- seqlock: Add raw_seqcount_try_begin (Suren Baghdasaryan)
- mm: Convert mm_lock_seq to a proper seqcount (Suren Baghdasaryan)
- mm: Introduce mmap_lock_speculate_{try_begin|retry} (Suren
Baghdasaryan)
- mm/gup: Use raw_seqcount_try_begin() (Peter Zijlstra)
Core perf enhancements:
- Reduce 'struct page' footprint of perf by mapping pages in advance
(Lorenzo Stoakes)
- Save raw sample data conditionally based on sample type (Yabin Cui)
- Reduce sampling overhead by checking sample_type in
perf_sample_save_callchain() and perf_sample_save_brstack() (Yabin
Cui)
- Export perf_exclude_event() (Namhyung Kim)
Uprobes scalability enhancements: (Andrii Nakryiko)
- Simplify find_active_uprobe_rcu() VMA checks
- Add speculative lockless VMA-to-inode-to-uprobe resolution
- Simplify session consumer tracking
- Decouple return_instance list traversal and freeing
- Ensure return_instance is detached from the list before freeing
- Reuse return_instances between multiple uretprobes within task
- Guard against kmemdup() failing in dup_return_instance()
AMD core PMU driver enhancements:
- Relax privilege filter restriction on AMD IBS (Namhyung Kim)
AMD RAPL energy counters support: (Dhananjay Ugwekar)
- Introduce topology_logical_core_id() (K Prateek Nayak)
- Remove the unused get_rapl_pmu_cpumask() function
- Remove the cpu_to_rapl_pmu() function
- Rename rapl_pmu variables
- Make rapl_model struct global
- Add arguments to the init and cleanup functions
- Modify the generic variable names to *_pkg*
- Remove the global variable rapl_msrs
- Move the cntr_mask to rapl_pmus struct
- Add core energy counter support for AMD CPUs
Intel core PMU driver enhancements:
- Support RDPMC 'metrics clear mode' feature (Kan Liang)
- Clarify adaptive PEBS processing (Kan Liang)
- Factor out functions for PEBS records processing (Kan Liang)
- Simplify the PEBS records processing for adaptive PEBS (Kan Liang)
Intel uncore driver enhancements: (Kan Liang)
- Convert buggy pmu->func_id use to pmu->registered
- Support more units on Granite Rapids"
* tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
perf: map pages in advance
perf/x86/intel/uncore: Support more units on Granite Rapids
perf/x86/intel/uncore: Clean up func_id
perf/x86/intel: Support RDPMC metrics clear mode
uprobes: Guard against kmemdup() failing in dup_return_instance()
perf/x86: Relax privilege filter restriction on AMD IBS
perf/core: Export perf_exclude_event()
uprobes: Reuse return_instances between multiple uretprobes within task
uprobes: Ensure return_instance is detached from the list before freeing
uprobes: Decouple return_instance list traversal and freeing
uprobes: Simplify session consumer tracking
uprobes: add speculative lockless VMA-to-inode-to-uprobe resolution
uprobes: simplify find_active_uprobe_rcu() VMA checks
mm: introduce mmap_lock_speculate_{try_begin|retry}
mm: convert mm_lock_seq to a proper seqcount
mm/gup: Use raw_seqcount_try_begin()
seqlock: add raw_seqcount_try_begin
perf/x86/rapl: Add core energy counter support for AMD CPUs
perf/x86/rapl: Move the cntr_mask to rapl_pmus struct
perf/x86/rapl: Remove the global variable rapl_msrs
...
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Merge tag 'for-6.14/block-20250118' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- NVMe pull requests via Keith:
- Target support for PCI-Endpoint transport (Damien)
- TCP IO queue spreading fixes (Sagi, Chaitanya)
- Target handling for "limited retry" flags (Guixen)
- Poll type fix (Yongsoo)
- Xarray storage error handling (Keisuke)
- Host memory buffer free size fix on error (Francis)
- MD pull requests via Song:
- Reintroduce md-linear (Yu Kuai)
- md-bitmap refactor and fix (Yu Kuai)
- Replace kmap_atomic with kmap_local_page (David Reaver)
- Quite a few queue freeze and debugfs deadlock fixes
Ming introduced lockdep support for this in the 6.13 kernel, and it
has (unsurprisingly) uncovered quite a few issues
- Use const attributes for IO schedulers
- Remove bio ioprio wrappers
- Fixes for stacked device atomic write support
- Refactor queue affinity helpers, in preparation for better supporting
isolated CPUs
- Cleanups of loop O_DIRECT handling
- Cleanup of BLK_MQ_F_* flags
- Add rotational support for null_blk
- Various fixes and cleanups
* tag 'for-6.14/block-20250118' of git://git.kernel.dk/linux: (106 commits)
block: Don't trim an atomic write
block: Add common atomic writes enable flag
md/md-linear: Fix a NULL vs IS_ERR() bug in linear_add()
block: limit disk max sectors to (LLONG_MAX >> 9)
block: Change blk_stack_atomic_writes_limits() unit_min check
block: Ensure start sector is aligned for stacking atomic writes
blk-mq: Move more error handling into blk_mq_submit_bio()
block: Reorder the request allocation code in blk_mq_submit_bio()
nvme: fix bogus kzalloc() return check in nvme_init_effects_log()
md/md-bitmap: move bitmap_{start, end}write to md upper layer
md/raid5: implement pers->bitmap_sector()
md: add a new callback pers->bitmap_sector()
md/md-bitmap: remove the last parameter for bimtap_ops->endwrite()
md/md-bitmap: factor behind write counters out from bitmap_{start/end}write()
md: Replace deprecated kmap_atomic() with kmap_local_page()
md: reintroduce md-linear
partitions: ldm: remove the initial kernel-doc notation
blk-cgroup: rwstat: fix kernel-doc warnings in header file
blk-cgroup: fix kernel-doc warnings in header file
nbd: fix partial sending
...
The static function in trace_events.c called update_cache() is too generic
and conflicts with the function defined in arch/openrisc/include/asm/pgtable.h
Rename it to update_mod_cache() to make it less generic.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250120172756.4ecfb43f@batman.local.home
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501210550.Ufrj5CRn-lkp@intel.com/
Fixes: b355247df1 ("tracing: Cache ":mod:" events for modules not loaded yet")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Merge tag 'kernel-6.14-rc1.pid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull pid_max namespacing update from Christian Brauner:
"The pid_max sysctl is a global value. For a long time the default
value has been 65535 and during the pidfd dicussions Linus proposed to
bump pid_max by default. Based on this discussion systemd started
bumping pid_max to 2^22. So all new systems now run with a very high
pid_max limit with some distros having also backported that change.
The decision to bump pid_max is obviously correct. It just doesn't
make a lot of sense nowadays to enforce such a low pid number. There's
sufficient tooling to make selecting specific processes without typing
really large pid numbers available.
In any case, there are workloads that have expections about how large
pid numbers they accept. Either for historical reasons or
architectural reasons. One concreate example is the 32-bit version of
Android's bionic libc which requires pid numbers less than 65536.
There are workloads where it is run in a 32-bit container on a 64-bit
kernel. If the host has a pid_max value greater than 65535 the libc
will abort thread creation because of size assumptions of
pthread_mutex_t.
That's a fairly specific use-case however, in general specific
workloads that are moved into containers running on a host with a new
kernel and a new systemd can run into issues with large pid_max
values. Obviously making assumptions about the size of the allocated
pid is suboptimal but we have userspace that does it.
Of course, giving containers the ability to restrict the number of
processes in their respective pid namespace indepent of the global
limit through pid_max is something desirable in itself and comes in
handy in general.
Independent of motivating use-cases the existence of pid namespaces
makes this also a good semantical extension and there have been prior
proposals pushing in a similar direction. The trick here is to
minimize the risk of regressions which I think is doable. The fact
that pid namespaces are hierarchical will help us here.
What we mostly care about is that when the host sets a low pid_max
limit, say (crazy number) 100 that no descendant pid namespace can
allocate a higher pid number in its namespace. Since pid allocation is
hierarchial this can be ensured by checking each pid allocation
against the pid namespace's pid_max limit. This means if the
allocation in the descendant pid namespace succeeds, the ancestor pid
namespace can reject it. If the ancestor pid namespace has a higher
limit than the descendant pid namespace the descendant pid namespace
will reject the pid allocation. The ancestor pid namespace will
obviously not care about this.
All in all this means pid_max continues to enforce a system wide limit
on the number of processes but allows pid namespaces sufficient leeway
in handling workloads with assumptions about pid values and allows
containers to restrict the number of processes in a pid namespace
through the pid_max interface"
* tag 'kernel-6.14-rc1.pid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
tests/pid_namespace: add pid_max tests
pid: allow pid_max to be set per pid namespace
A typo was introduced when adding the ":mod:" command that did
a "#if CONFIG_MODULES" instead of a "#ifdef CONFIG_MODULES".
Fix it.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/20250120125745.4ac90ca6@gandalf.local.home
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501190121.E2CIJuUj-lkp@intel.com/
Fixes: b355247df1 ("tracing: Cache ":mod:" events for modules not loaded yet")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Module functions can be set to set_ftrace_filter before the module is
loaded.
# echo :mod:snd_hda_intel > set_ftrace_filter
This will enable all the functions for the module snd_hda_intel. If that
module is not loaded, it is "cached" in the trace array for when the
module is loaded, its functions will be traced.
But this is not implemented in the kernel command line. That's because the
kernel command line filtering is added very early in boot up as it is
needed to be done before boot time function tracing can start, which is
also available very early in boot up. The code used by the
"set_ftrace_filter" file can not be used that early as it depends on some
other initialization to occur first. But some of the functions can.
Implement the ":mod:" feature of "set_ftrace_filter" in the kernel command
line parsing. Now function tracing on just a single module that is loaded
at boot up can be done.
Adding:
ftrace=function ftrace_filter=:mod:sna_hda_intel
To the kernel command line will only enable the sna_hda_intel module
functions when the module is loaded, and it will start tracing.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250116175832.34e39779@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When the :mod: command is written into /sys/kernel/tracing/set_event (or
that file within an instance), if the module specified after the ":mod:"
is not yet loaded, it will store that string internally. When the module
is loaded, it will enable the events as if the module was loaded when the
string was written into the set_event file.
This can also be useful to enable events that are in the init section of
the module, as the events are enabled before the init section is executed.
This also works on the kernel command line:
trace_event=:mod:<module>
Will enable the events for <module> when it is loaded.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250116143533.514730995@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add a :mod: command to enable only events from a given module from the
set_events file.
echo '*:mod:<module>' > set_events
Or
echo ':mod:<module>' > set_events
Will enable all events for that module. Specific events can also be
enabled via:
echo '<event>:mod:<module>' > set_events
Or
echo '<system>:<event>:mod:<module>' > set_events
Or
echo '*:<event>:mod:<module>' > set_events
The ":mod:" keyword is consistent with the function tracing filter to
enable functions from a given module.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/20250116143533.214496360@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The function graph tracer has become generic so that kretprobes and BPF
can use it along with function graph tracing itself. Some of the
infrastructure was specific for function graph tracing such as recording
the calltime and return time of the functions. Calling the clock code on a
high volume function does add overhead. The calculation of the calltime
was removed from the generic code and placed into the function graph
tracer itself so that the other users did not incur this overhead as they
did not need that timestamp.
The calltime field was still kept in the generic return entry structure
and the function graph return entry callback filled it as that structure
was passed to other code.
But this broke both irqsoff and wakeup latency tracer as they still
depended on the trace structure containing the calltime when the option
display-graph is set as it used some of those same functions that the
function graph tracer used. But now the calltime was not set and was just
zero. This caused the calculation of the function time to be the absolute
value of the return timestamp and not the length of the function.
# cd /sys/kernel/tracing
# echo 1 > options/display-graph
# echo irqsoff > current_tracer
The tracers went from:
# REL TIME CPU TASK/PID |||| DURATION FUNCTION CALLS
# | | | | |||| | | | | | |
0 us | 4) <idle>-0 | d..1. | 0.000 us | irqentry_enter();
3 us | 4) <idle>-0 | d..2. | | irq_enter_rcu() {
4 us | 4) <idle>-0 | d..2. | 0.431 us | preempt_count_add();
5 us | 4) <idle>-0 | d.h2. | | tick_irq_enter() {
5 us | 4) <idle>-0 | d.h2. | 0.433 us | tick_check_oneshot_broadcast_this_cpu();
6 us | 4) <idle>-0 | d.h2. | 2.426 us | ktime_get();
9 us | 4) <idle>-0 | d.h2. | | tick_nohz_stop_idle() {
10 us | 4) <idle>-0 | d.h2. | 0.398 us | nr_iowait_cpu();
11 us | 4) <idle>-0 | d.h1. | 1.903 us | }
11 us | 4) <idle>-0 | d.h2. | | tick_do_update_jiffies64() {
12 us | 4) <idle>-0 | d.h2. | | _raw_spin_lock() {
12 us | 4) <idle>-0 | d.h2. | 0.360 us | preempt_count_add();
13 us | 4) <idle>-0 | d.h3. | 0.354 us | do_raw_spin_lock();
14 us | 4) <idle>-0 | d.h2. | 2.207 us | }
15 us | 4) <idle>-0 | d.h3. | 0.428 us | calc_global_load();
16 us | 4) <idle>-0 | d.h3. | | _raw_spin_unlock() {
16 us | 4) <idle>-0 | d.h3. | 0.380 us | do_raw_spin_unlock();
17 us | 4) <idle>-0 | d.h3. | 0.334 us | preempt_count_sub();
18 us | 4) <idle>-0 | d.h1. | 1.768 us | }
18 us | 4) <idle>-0 | d.h2. | | update_wall_time() {
[..]
To:
# REL TIME CPU TASK/PID |||| DURATION FUNCTION CALLS
# | | | | |||| | | | | | |
0 us | 5) <idle>-0 | d.s2. | 0.000 us | _raw_spin_lock_irqsave();
0 us | 5) <idle>-0 | d.s3. | 312159583 us | preempt_count_add();
2 us | 5) <idle>-0 | d.s4. | 312159585 us | do_raw_spin_lock();
3 us | 5) <idle>-0 | d.s4. | | _raw_spin_unlock() {
3 us | 5) <idle>-0 | d.s4. | 312159586 us | do_raw_spin_unlock();
4 us | 5) <idle>-0 | d.s4. | 312159587 us | preempt_count_sub();
4 us | 5) <idle>-0 | d.s2. | 312159587 us | }
5 us | 5) <idle>-0 | d.s3. | | _raw_spin_lock() {
5 us | 5) <idle>-0 | d.s3. | 312159588 us | preempt_count_add();
6 us | 5) <idle>-0 | d.s4. | 312159589 us | do_raw_spin_lock();
7 us | 5) <idle>-0 | d.s3. | 312159590 us | }
8 us | 5) <idle>-0 | d.s4. | 312159591 us | calc_wheel_index();
9 us | 5) <idle>-0 | d.s4. | | enqueue_timer() {
9 us | 5) <idle>-0 | d.s4. | | wake_up_nohz_cpu() {
11 us | 5) <idle>-0 | d.s4. | | native_smp_send_reschedule() {
11 us | 5) <idle>-0 | d.s4. | 312171987 us | default_send_IPI_single_phys();
12408 us | 5) <idle>-0 | d.s3. | 312171990 us | }
12408 us | 5) <idle>-0 | d.s3. | 312171991 us | }
12409 us | 5) <idle>-0 | d.s3. | 312171991 us | }
Where the calculation of the time for each function was the return time
minus zero and not the time of when the function returned.
Have these tracers also save the calltime in the fgraph data section and
retrieve it again on the return to get the correct timings again.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/20250113183124.61767419@gandalf.local.home
Fixes: f1f36e22be ("ftrace: Have calltime be saved in the fgraph storage")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
In the loop of __rb_map_vma(), the 's' variable is calculated from the
same logic that nr_pages is and they both come from nr_subbufs. But the
relationship is not obvious and there's a WARN_ON_ONCE() around the 's'
variable to make sure it never becomes equal to nr_subbufs within the
loop. If that happens, then the code is buggy and needs to be fixed.
The 'page' variable is calculated from cpu_buffer->subbuf_ids[s] which is
an array of 'nr_subbufs' entries. If the code becomes buggy and 's'
becomes equal to or greater than 'nr_subbufs' then this will be an out of
bounds hit before the WARN_ON() is triggered and the code exiting safely.
Make the 'page' initialization consistent with the code logic and assign
it after the out of bounds check.
Link: https://lore.kernel.org/20250110162612.13983-1-aha310510@gmail.com
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
[ sdr: rewrote change log ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Currently there are two ways of identifying an empty ring-buffer. One
relying on the current status of the commit / reader page
(rb_per_cpu_empty()) and the other on the write and read counters
(rb_num_of_entries() used in rb_get_reader_page()).
with rb_num_of_entries(). This intends to ease later
introduction of ring-buffer writers which are out of the kernel control
and with whom, the only information available is through the meta-page
counters.
Link: https://lore.kernel.org/20250108114536.627715-2-vdonnefort@google.com
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add ftrace_get_entry_ip() which is only for ftrace based probes, and use
it for kprobe multi probes because they are based on fprobe which uses
ftrace instead of kprobes.
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/173566081414.878879.10631096557346094362.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
In __trace_kprobe_create(), if something fails it must goto error block
to free objects. But when strdup() a symbol, it returns without that.
Fix it to goto the error block to free objects correctly.
Link: https://lore.kernel.org/all/173643297743.1514810.2408159540454241947.stgit@devnote2/
Fixes: 6212dd2968 ("tracing/kprobes: Use dyn_event framework for kprobe events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When kprobe multi bpf program can't be executed due to recursion check,
we currently return 0 (success) to fprobe layer where it's ignored for
standard kprobe multi probes.
For kprobe session the success return value will make fprobe layer to
install return probe and try to execute it as well.
But the return session probe should not get executed, because the entry
part did not run. FWIW the return probe bpf program most likely won't get
executed, because its recursion check will likely fail as well, but we
don't need to run it in the first place.. also we can make this clear
and obvious.
It also affects missed counts for kprobe session program execution, which
are now doubled (extra count for not executed return probe).
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20250106175048.1443905-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit ef1b808e3b ("bpf: Fix UAF via mismatching bpf_prog/attachment
RCU flavors") resolved a possible UAF issue in uprobes that attach
non-sleepable bpf prog by explicitly waiting for a tasks-trace-RCU grace
period. But, in the current implementation, synchronize_rcu_tasks_trace
is included within the mutex critical section, which increases the
length of the critical section and may affect performance. So let's move
out synchronize_rcu_tasks_trace from mutex CS.
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20250104013946.1111785-1-pulehui@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Since POLLIN will not be flushed until the hist file is read, the user
needs to repeatedly read() and poll() on the hist file for monitoring the
event continuously. But the read() is somewhat redundant when the user is
only monitoring for event updates.
Add POLLPRI poll event on the hist file so the event returns when a
histogram is updated after open(), poll() or read(). Thus it is possible
to wait for the next event without having to issue a read().
Cc: Shuah Khan <shuah@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173527248770.464571.2536902137325258133.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Add poll syscall support on the `hist` file. The Waiter will be waken
up when the histogram is updated with POLLIN.
Currently, there is no way to wait for a specific event in userspace.
So user needs to peek the `trace` periodicaly, or wait on `trace_pipe`.
But it is not a good idea to peek at the `trace` for an event that
randomly happens. And `trace_pipe` is not coming back until a page is
filled with events.
This allows a user to wait for a specific event on the `hist` file. User
can set a histogram trigger on the event which they want to monitor
and poll() on its `hist` file. Since this poll() returns POLLIN, the next
poll() will return soon unless a read() happens on that hist file.
NOTE: To read the hist file again, you must set the file offset to 0,
but just for monitoring the event, you may not need to read the
histogram.
Cc: Shuah Khan <shuah@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173527247756.464571.14236296701625509931.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
When the function tracing_set_tracer() switched over to using the guard()
infrastructure, it did not need to save the 'ret' variable and would just
return the value when an error arised, instead of setting ret and jumping
to an out label.
When CONFIG_TRACER_SNAPSHOT is enabled, it had code that expected the
"ret" variable to be initialized to zero and had set 'ret' while holding
an arch_spin_lock() (not used by guard), and then upon releasing the lock
it would check 'ret' and exit if set. But because ret was only set when an
error occurred while holding the locks, 'ret' would be used uninitialized
if there was no error. The code in the CONFIG_TRACER_SNAPSHOT block should
be self contain. Make sure 'ret' is also set when no error occurred.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250106111143.2f90ff65@gandalf.local.home
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202412271654.nJVBuwmF-lkp@intel.com/
Fixes: d33b10c0c7 ("tracing: Switch trace.c code over to use guard()")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
- Add needed READ_ONCE() around access to the fgraph array element
The updates to the fgraph array can happen when callbacks are registered
and unregistered. The __ftrace_return_to_handler() can handle reading
either the old value or the new value. But once it reads that value
it must stay consistent otherwise the check that looks to see if the
value is a stub may show false, but if the compiler decides to re-read
after that check, it can be true which can cause the code to crash
later on.
- Make function profiler use the top level ops for filtering again
When function graph became available for instances, its filter ops became
independent from the top level set_ftrace_filter. In the process the
function profiler received its own filter ops as well. But the function
profiler uses the top level set_ftrace_filter file and does not have one
of its own. In giving it its own filter ops, it lost any user interface
it once had. Make it use the top level set_ftrace_filter file again.
This fixes a regression.
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Merge tag 'ftrace-v6.13-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull ftrace fixes from Steven Rostedt:
- Add needed READ_ONCE() around access to the fgraph array element
The updates to the fgraph array can happen when callbacks are
registered and unregistered. The __ftrace_return_to_handler() can
handle reading either the old value or the new value. But once it
reads that value it must stay consistent otherwise the check that
looks to see if the value is a stub may show false, but if the
compiler decides to re-read after that check, it can be true which
can cause the code to crash later on.
- Make function profiler use the top level ops for filtering again
When function graph became available for instances, its filter ops
became independent from the top level set_ftrace_filter. In the
process the function profiler received its own filter ops as well.
But the function profiler uses the top level set_ftrace_filter file
and does not have one of its own. In giving it its own filter ops, it
lost any user interface it once had. Make it use the top level
set_ftrace_filter file again. This fixes a regression.
* tag 'ftrace-v6.13-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ftrace: Fix function profiler's filtering functionality
fgraph: Add READ_ONCE() when accessing fgraph_array[]
Commit c132be2c4f ("function_graph: Have the instances use their own
ftrace_ops for filtering"), function profiler (enabled via
function_profile_enabled) has been showing statistics for all functions,
ignoring set_ftrace_filter settings.
While tracers are instantiated, the function profiler is not. Therefore, it
should use the global set_ftrace_filter for consistency. This patch
modifies the function profiler to use the global filter, fixing the
filtering functionality.
Before (filtering not working):
```
root@localhost:~# echo 'vfs*' > /sys/kernel/tracing/set_ftrace_filter
root@localhost:~# echo 1 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# sleep 1
root@localhost:~# echo 0 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# head /sys/kernel/tracing/trace_stat/*
Function Hit Time Avg
s^2
-------- --- ---- ---
---
schedule 314 22290594 us 70989.15 us
40372231 us
x64_sys_call 1527 8762510 us 5738.382 us
3414354 us
schedule_hrtimeout_range 176 8665356 us 49234.98 us
405618876 us
__x64_sys_ppoll 324 5656635 us 17458.75 us
19203976 us
do_sys_poll 324 5653747 us 17449.83 us
19214945 us
schedule_timeout 67 5531396 us 82558.15 us
2136740827 us
__x64_sys_pselect6 12 3029540 us 252461.7 us
63296940171 us
do_pselect.constprop.0 12 3029532 us 252461.0 us
63296952931 us
```
After (filtering working):
```
root@localhost:~# echo 'vfs*' > /sys/kernel/tracing/set_ftrace_filter
root@localhost:~# echo 1 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# sleep 1
root@localhost:~# echo 0 > /sys/kernel/tracing/function_profile_enabled
root@localhost:~# head /sys/kernel/tracing/trace_stat/*
Function Hit Time Avg
s^2
-------- --- ---- ---
---
vfs_write 462 68476.43 us 148.217 us
25874.48 us
vfs_read 641 9611.356 us 14.994 us
28868.07 us
vfs_fstat 890 878.094 us 0.986 us
1.667 us
vfs_fstatat 227 757.176 us 3.335 us
18.928 us
vfs_statx 226 610.610 us 2.701 us
17.749 us
vfs_getattr_nosec 1187 460.919 us 0.388 us
0.326 us
vfs_statx_path 297 343.287 us 1.155 us
11.116 us
vfs_rename 6 291.575 us 48.595 us
9889.236 us
```
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/20250101190820.72534-1-enjuk@amazon.com
Fixes: c132be2c4f ("function_graph: Have the instances use their own ftrace_ops for filtering")
Signed-off-by: Kohei Enju <enjuk@amazon.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
