Commit Graph

431 Commits

Author SHA1 Message Date
Linus Torvalds
6439079365 Probes updates for v7.3:
- probes: Advanced BTF typecasting and variable fetch enhancements
   . Typecast support across probe events: Extended BTF typecasting syntax
     (e.g., (STRUCT)PARAM->MEMBER) to kprobes, uprobes, and fprobes on
     function entry and return.
   . Nested typecasts: Added support for chaining and nesting typecasts up
     to 3 levels, including casting registers and stack variables.
   . Field specifier option: Added (STRUCT,FIELD) syntax to emulate
     container_of(), allowing retrieval of parent structures from member
     pointers.
   . $current variable support: Introduced $current special variable to
     access the running task_struct via BTF dereferencing.
   . Per-CPU variable access: Added this_cpu_read() and this_cpu_ptr()
     fetcharg methods to trace CPU-local data safely.
   . Fetcharg bytecode dumper: Added CONFIG_PROBE_EVENTS_DUMP_FETCHARG to
     dump the compiled fetcharg bytecode instructions as comments in
     dynamic_events.
   . Extended symbol name handling: Removed the MAX_COMMON_HEAD_LEN limit
     and extended MAX_ARGSTR_LEN to 256 bytes, enabling probing of long
     symbols, mangled Rust symbols and complex BTF expressions.
   . eprobe variable syntax: Allowed eprobes to reference event fields
     directly without requiring a '$' prefix.
   . Cleanup unused parameters, redundant codes, duplicate macros and
     pointer arithmetic.
   . Use a ternary operator for simplifying fetch_type_from_btf_type().
 
 - bootconfig / boottime-trace: Expanded dynamic probe support
   . Added boot-time tracing configuration support for event probes
     (eprobes), function probes (fprobes), and tracepoint probes
     (tprobes).
   . ftrace2bootconfig: Allowed comment lines ('#') in dynamic_events file.
 
 - fprobe / kprobe: Optimization, robustness, and cleanups
   . fprobe: Simplified fprobe_remove_ips() by reusing graph and ftrace
     helpers.
   . fprobe: Removed __packed attribute from struct __fprobe_header to avoid
     unaligned memory access penalties on RISC architectures.
   . kprobe & fprobe: Removed redundant memset() calls in perf event probe
     handlers.
   . kprobes: Replaced legacy __ASSEMBLY__ with __ASSEMBLER__ in header
     files.
 
 - selftests & refactoring:
   . Refactored parse_probe_arg() and parse_probe_vars(), and eliminated
     recursion in probe argument parsing to protect kernel stack depth.
   . Added selftests for BTF typecasts and module probing without module
     prefixes.
   . Forced LC_ALL=C in ftracetest to prevent test failures on localized
     systems.
   . Refactored btf_type_skip_modifiers() to remove ignored id parameter.
   . Sorted ERRORS list in trace_probe.h alphabetically.
   . Fixed typo in fprobe docs, and trace_fprobe function name.
   . Renamed FETCH_OP_DATA to FETCH_OP_IMMSTR.
   . Made file offset error message probe-agnostic.
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Merge tag 'probes-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:
 "BTF typecasting and variable fetch enhancements:

   - Typecast support across probe events: Extended BTF typecasting
     syntax (e.g., (STRUCT)PARAM->MEMBER) to kprobes, uprobes, and
     fprobes on function entry and return

   - Nested typecasts: Added support for chaining and nesting typecasts
     up to 3 levels, including casting registers and stack variables

   - Field specifier option: Added (STRUCT,FIELD) syntax to emulate
     container_of(), allowing retrieval of parent structures from member
     pointers

   - $current variable support: Introduced $current special variable to
     access the running task_struct via BTF dereferencing

   - Per-CPU variable access: Added this_cpu_read() and this_cpu_ptr()
     fetcharg methods to trace CPU-local data safely

   - Fetcharg bytecode dumper: Added CONFIG_PROBE_EVENTS_DUMP_FETCHARG
     to dump the compiled fetcharg bytecode instructions as comments in
     dynamic_events

   - Extended symbol name handling: Removed the MAX_COMMON_HEAD_LEN
     limit and extended MAX_ARGSTR_LEN to 256 bytes, enabling probing of
     long symbols, mangled Rust symbols and complex BTF expressions

   - eprobe variable syntax: Allowed eprobes to reference event fields
     directly without requiring a '$' prefix

   - Cleanup unused parameters, redundant codes, duplicate macros and
     pointer arithmetic

   - Use a ternary operator for simplifying fetch_type_from_btf_type()

  Expanded boot time dynamic probe support:

   - Add boot-time tracing configuration support for event probes
     (eprobes), function probes (fprobes), and tracepoint probes
     (tprobes)

   - Allow comment lines ('#') in dynamic_events file

  Optimization, robustness, and cleanups:

   - Simplify fprobe_remove_ips() by reusing graph and ftrace helpers

   - Remove __packed attribute from struct __fprobe_header to avoid
     unaligned memory access penalties on RISC architectures

   - Remove redundant memset() calls in perf event probe handlers

   - Replace legacy __ASSEMBLY__ with __ASSEMBLER__ in header files

  Selftests & refactoring:

   - Refactor parse_probe_arg() and parse_probe_vars(), and eliminate
     recursion in probe argument parsing to protect kernel stack depth

   - Add selftests for BTF typecasts and module probing without module
     prefixes

   - Force LC_ALL=C in ftracetest to prevent test failures on localized
     systems

   - Refactor btf_type_skip_modifiers() to remove ignored id parameter

   - Sort ERRORS list in trace_probe.h alphabetically

   - Fix typo in fprobe docs, and trace_fprobe function name

   - Rename FETCH_OP_DATA to FETCH_OP_IMMSTR

   - Make file offset error message probe-agnostic"

* tag 'probes-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (37 commits)
  fprobe: Simplify fprobe_remove_ips() by reusing existing helpers
  tracing/boot: Add support for eprobe, fprobe, and tprobe events
  selftests/ftrace: Force C locale in ftracetest
  tracing/probes: Treating longer symbol name on event comparation
  docs: trace: fprobe: fix 'thos' spelling
  tracing/probes: Fix extra whitespace in trace_probe_kernel.h
  tracing/kprobe: Remove redundant memset in kprobe_perf_func()
  tracing/fprobe: Remove redundant memset in fentry_perf_func()
  tracing/fprobe: Remove redundant snprintf in trace_fprobe_match_command_head()
  tracing/probes: Simplify BTF_KIND_PTR case in fetch_type_from_btf_type()
  tracing/probes: Cleanup pointer arithmetic in store_trace_entry_data()
  tracing/probes: Remove unused parameter from parse_probe_var_retval()
  tracing/probes: Remove redundant bounds check in trace_probe_compare_arg_type()
  tracing/probes: Remove redundant boolean conversion in trace_probe_has_single_file()
  tracing/probes: Remove duplicate MAX_ARRAY_LEN macro definition
  selftests/ftrace: Add test case for a symbol in a module without module name
  tracing/probes: Eliminate recursion in parse_probe_arg()
  tracing/probes: Extend max length of argument string
  tracing/probes: Sort ERRORS list in trace_probe.h alphabetically
  tracing/probes: Refactor parse_probe_arg()
  ...
2026-08-20 15:11:52 -07:00
Linus Torvalds
0f23d56f17 linux_kselftest-next-7.3-rc1
Fixes zram test failure in kernel_gte() when using dash and a spelling
 error in ftrace poll test comment.
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Merge tag 'linux_kselftest-next-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest update from Shuah Khan:
 "Fix zram test failure in kernel_gte() when using dash and a spelling
  error in ftrace poll test comment"

* tag 'linux_kselftest-next-7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/zram: fix kernel_gte() for POSIX sh
  selftests/ftrace: fix spelling error in poll test comment
2026-08-17 20:52:03 -07:00
Rui Qi
c13fcd3951 selftests/ftrace: Force C locale in ftracetest
Some ftracetest test cases parse command output by matching English
field names. Tools such as readelf may localize their output via
gettext, while ftracetest currently inherits the user locale from
the environment.

If a translated field name is printed, parsing can fail even though
the tested kernel behavior is unchanged. For example, add_remove_uprobe
can fail to find the ELF entry point and then write a uprobe event with
a missing offset.

Export LC_ALL=C in the top-level ftracetest runner so every test case
gets stable command output by default.

Link: https://lore.kernel.org/all/20260807081512.2974757-2-qirui.001@bytedance.com/

Signed-off-by: Rui Qi <qirui.001@bytedance.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-08-08 01:06:59 +09:00
Rui Qi
24aa630f62 selftests/ftrace: Convert ELF entry point to file offset in uprobe test
The add_remove_uprobe test uses readelf -h to obtain the ELF entry
point (e_entry) and passes it directly as the offset to uprobe_events.
However, uprobe_events expects a file offset, not a virtual address.

For PIE binaries, the virtual address happens to equal the file offset
because the first LOAD segment has p_vaddr == p_offset, so the test
works by coincidence. But for non-PIE executables, e_entry is an
absolute virtual address that can far exceed the file size. When the
probe is enabled, uprobe_register() checks offset > i_size_read(inode)
and rejects it with -EINVAL.

Fix this by converting the virtual address to a file offset using the
ELF program headers: scan readelf -lW output for the LOAD segment
containing the entry point, then compute file_offset = e_entry -
p_vaddr + p_offset. For PIE binaries the result is unchanged; for
non-PIE binaries the offset is correctly translated.

The conversion uses only POSIX shell primitives, with no dependency on
gawk or perl.

Link: https://lore.kernel.org/all/20260807081512.2974757-3-qirui.001@bytedance.com/

Fixes: dc4b165855 ("selftests/ftrace: Use readelf to find entry point in uprobe test")
Cc: stable@vger.kernel.org
Signed-off-by: Rui Qi <qirui.001@bytedance.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-08-08 01:02:21 +09:00
Martin Kaiser
6e3abef2a2 selftests/ftrace: refactor eprobes test to fix argument checks
The add/remove eprobe test installs an eprobe for the openat syscall and
runs ls. It checks the filenames that were opened by ls against a
whitelist and a blacklist.

Commit 206b25c090 ("tracing: eprobe: read the complete FILTER_PTR_STRING
pointer") fixed access to some string fields in eprobes. This triggers
test failures as the blacklist does not allow relative paths for the
openat parameters.

What makes this test unstable is the fact that the openat calls vary a
lot between different systems.

Refactor the test to make it more robust. "cd <directory>" will issue a
chdir syscall with the target directory as parameter. Set an eprobe on
the sys_enter_chdir event and filter for the exact directory name. Allow
(fault) as fallback.

Link: https://lore.kernel.org/all/20260804194705.760893-1-martin@kaiser.cx/

Fixes: 206b25c090 ("tracing: eprobe: read the complete FILTER_PTR_STRING pointer")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202607151010.b68428e1-lkp@intel.com
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-08-05 09:01:48 +09:00
Masami Hiramatsu (Google)
1a087033a6 selftests/ftrace: Reset triggers at top level before instance loop
When running instance tests, 'ftracetest' creates a new ftrace instance
and runs the tests inside it. Before starting each test, it executes
'initialize_system()' to reset the ftrace state to initial-state.

However, since 'initialize_system()' is executed in the context of the
instance directory, it only cleans up triggers and filters of that
instance.
Any triggers or dynamic events left behind in the top-level instance by
previous failed top-level tests, are left completely untouched. These
top-level leftovers can cause subsequent instance-based tests to fail
or even crash the kernel.

Fix this by executing 'initialize_system()' in the top-level tracing
directory once before entering the instance loop.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/178425671889.84440.9477850701738666404.stgit@devnote2
Fixes: b5b77be812 ("selftests: ftrace: Allow some tests to be run in a tracing instance")
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2026-07-24 13:43:18 -04:00
Masami Hiramatsu (Google)
1a416ae446 selftests/ftrace: Add test case for a symbol in a module without module name
Add a test case for probing on a symbol in a module without module name.
When probing on a symbol in a module, ftrace accepts both the syntax that
<MODNAME>:<SYMBOL> and <SYMBOL>. Current test case only checks the former
syntax. This adds a test for the latter one.

Link: https://lore.kernel.org/all/169846405196.88147.17766692778800222203.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-15 11:06:18 +09:00
Masami Hiramatsu
1a0ffe10bf tracing/probes: Eliminate recursion in parse_probe_arg()
To avoid potential stack overflows on limited kernel stacks, convert
parse_probe_arg() from a recursive function into a loop-based
implementation with a simple local state stack.

Since recursion is eliminated using a loop with a fixed-size
stack in the context, this restricts the dereference nesting
depth. The maximum nesting depth of dereferences is now restricted
to the same limit as typecasts (TRACEPROBE_MAX_NESTED_LEVEL, which
is 8) and reports the same TOO_MANY_NESTED error. Update ftrace
selftests to reflect this restriction and simplify the checks.

Note that this change slightly alters the behavior of nested
dereferencing in fetcharg. Previously, dereferencing without BTF
allowed for up to 14 levels of nesting, whereas dereferencing
with BTF was limited to 3 levels. With this change, the nesting
depth is now limited to 8 levels in both cases.

Link: https://lore.kernel.org/all/178399141396.27810.5390060618628718661.stgit@devnote2/

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-14 22:43:40 +09:00
Masami Hiramatsu
47e4ec6871 tracing/probes: Extend max length of argument string
To support BTF argument parsing (such as accessing fields within nested
structures via typecasting), the maximum argument string length needs
to be extended. Extend MAX_ARGSTR_LEN from 63 to 255.

Since MAX_ARGSTR_LEN was previously reused to format command heads in
trace_*probe_match_command_head() functions, introduce a dedicated
MAX_COMMON_HEAD_LEN (63) macro for matching command heads and switch
these functions to use the new macro.

Link: https://lore.kernel.org/all/178399140457.27810.11387684872148824707.stgit@devnote2/

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-14 22:43:40 +09:00
Masami Hiramatsu (Google)
7d8d6ad659 tracing/probes: Add a new testcase for BTF typecasts
With the introduction of container_of-style BTF typecasting and
per-CPU variable access support in trace probes, we need a way to
verify their functionality and prevent regressions.

Add a new ftrace kselftest and update the trace event sample module
to test and validate these features.

Specifically, update the trace-events-sample module to set up a
periodic timer whose callback accesses a per-CPU counter. Introduce
a new sample trace event, foo_timer_fn, to trace this callback
and log the current counter value.

Then, add a new test case, btf_probe_event.tc, which defines a
dynamic probe on the timer callback. The probe uses BTF typecasting
to recover the parent structure from the timer argument and
this_cpu_read() to fetch the per-CPU counter. The test verifies
the integrity of the implementation by ensuring the values
recorded by the dynamic probe match those from the static tracepoint.

Link: https://lore.kernel.org/all/178271368625.1176915.13502654445483530822.stgit@devnote2/

Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-14 22:43:16 +09:00
Wang Yan
20f01a5565 selftests/ftrace: fix spelling error in poll test comment
Fix typo "happned" -> "happened" in ftrace poll test comment.

Link: https://lore.kernel.org/r/20260702015634.366201-1-wangyan01@kylinos.cn
Signed-off-by: Wang Yan <wangyan01@kylinos.cn>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2026-07-10 11:29:22 -06:00
Steven Rostedt
c5c413534d selftests/tracing: Have trigger-hist-poll.tc use sched_process_exit
Currently trigger-hist-poll.tc uses sched_process_free to test the polling
of the histogram file. The way it does that is to run sleep, then execute
the poll.c code that polls on the sched_process_free for up to 4 seconds
to test that when sleep triggers the sched_process_free trace event, it
will update the histogram and wake the poll.c code up.

The issue is that sched_process_free trace event is called by
delayed_put_task_struct() which is called after a RCU grace period has
ended. If CONFIG_RCU_LAZY is enabled, RCU callbacks are batched together
and do not execute right away. This causes the delayed_put_task_struct()
to be called after the poll.c function finishes and it will report an
error that it did not wake up on the event. That's because the event
didn't trigger during its wait time.

Use sched_process_exit instead, which is called when a process exits and
doesn't depend on RCU callbacks that may be delayed.

Link: https://lore.kernel.org/r/20260708163436.058cc3df@gandalf.local.home
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2026-07-10 10:14:42 -06:00
Steven Rostedt
22a78be412 selftests/ftrace: Fix reading enabled_functions in add_remove_fprobe_module test
The add_remove_fprobe_module test checks the number of functions added to
the enabled_functions file to make sure that the functions added or
removed is as expected. The issue is that it expects this file to be empty
on start up.

Now that systemd uses BPF that attaches to functions via ftrace, this file
is not empty in several systems:

 # cat /sys/kernel/tracing/enabled_functions
 bpf_lsm_file_open (1) R   D   M 	tramp: ftrace_regs_caller+0x0/0x61 (call_direct_funcs+0x0/0x50)
	direct(jmp)-->bpf_trampoline_6442529439+0x0/0xe9

Change the test to read the number of lines in enabled_functions at the
start of the test and subtract that from the value of the count for the
checks within the test.

Link: https://lore.kernel.org/r/20260708153239.055d56dd@gandalf.local.home
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2026-07-10 10:14:42 -06:00
Masami Hiramatsu (Google)
427c240a02 tracing/probes: Allow eprobe to use variable without $ prefix
The commit 69efd863a7 ("tracing/eprobes: Allow use of BTF names
to dereference pointers") allows eprobe to use event field without
"$" prefix when it is used with typecast, it is natual to allow it
without typecast.

Link: https://lore.kernel.org/all/178271358117.1176915.13520279547897961254.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-02 21:12:40 +09:00
Linus Torvalds
3eb20a97b3 linux_kselftest-next-7.2-rc1-second
Fixes ftrace test and kselftest document
 
 -- docs: remove obsolete wiki link from kselftest.rst
 -- ftrace: drop invalid top-level local in test_ownership
 -- ftrace: Fix trace_marker_raw test on 64K page kernels
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Merge tag 'linux_kselftest-next-7.2-rc1-second' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull more kselftest updates from Shuah Khan:
 "Docs:
    -remove obsolete wiki link from kselftest.rst

  ftrace:
    - drop invalid top-level local in test_ownership
    - Fix trace_marker_raw test on 64K page kernels"

* tag 'linux_kselftest-next-7.2-rc1-second' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  docs: kselftest: remove link to obsolete wiki
  selftests/ftrace: Fix trace_marker_raw test on 64K page kernels
  selftests/ftrace: Drop invalid top-level local in test_ownership
2026-06-23 07:35:37 -07:00
Tianchen Ding
65f26d15f7 selftests/ftrace: Fix trace_marker_raw test on 64K page kernels
On ARM64 kernels with 64K pages, the trace_marker_raw test fails because
bash's printf builtin uses stdio buffering which splits output into
multiple small write() calls to the tracefs file. Since each individual
write is within TRACE_MARKER_MAX_SIZE (4096), they all succeed, causing
the "too big" write test to incorrectly pass.

Fix by writing through dd with iflag=fullblock to guarantee a single
atomic write() syscall to trace_marker_raw.

Link: https://lore.kernel.org/r/20260601023251.1916483-1-dtcccc@linux.alibaba.com
Fixes: 37f4660138 ("selftests/tracing: Add basic test for trace_marker_raw file")
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2026-06-17 17:17:26 -06:00
Cao Ruichuang
808c447df2 selftests/ftrace: Drop invalid top-level local in test_ownership
test_ownership.tc is sourced by ftracetest under /bin/sh.

The script currently declares mount_point with local at file scope,
which makes /bin/sh abort with "local: not in a function" before the
test can reach the eventfs ownership checks.

Replace the top-level local declaration with a normal shell variable so
kernels that support the gid= tracefs mount option can run the test at
all.

Link: https://lore.kernel.org/r/20260407102613.81419-1-create0818@163.com
Fixes: 8b55572e51 ("tracing/selftests: Add tracefs mount options test")
Signed-off-by: Cao Ruichuang <create0818@163.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2026-06-17 16:27:17 -06:00
Masami Hiramatsu (Google)
85e0f27dd1 tracing/probes: Point the error offset correctly for eprobe argument error
Fix to point the error offset correctly for eprobe argument error.
In the cleanup commit 1b8b0cd754 ("tracing/probes: Move event parameter
fetching code to common parser"), due to incorrect backward compatibility
aimed at conforming to the test specifications, the error location was set
to 0 when a non-existent formal parameter was specified for Eprobe.
However, this should be corrected in both the test and the implementation
to point correct error position.

Link: https://lore.kernel.org/all/177967567399.209006.1451571244515632097.stgit@devnote2/

Fixes: 1b8b0cd754 ("tracing/probes: Move event parameter fetching code to common parser")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2026-05-30 22:45:50 +09:00
Masami Hiramatsu (Google)
453553e1ed selftests/ftrace: Add a testcase for multiple fprobe events
Add a testcase for multiple fprobe events on the same function
so that it clears ftrace hash map correctly when removing the
events.

Link: https://lore.kernel.org/all/177669370353.132053.16801520791509406141.stgit@mhiramat.tok.corp.google.com/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-04-22 09:26:46 +09:00
Masami Hiramatsu (Google)
132001e9f9 selftests/ftrace: Add a testcase for fprobe events on module
Add a testcase for fprobe events on module, which unloads a kernel
module on which fprobe events are probing and ensure the ftrace
hash map is cleared correctly.

Link: https://lore.kernel.org/all/177669369564.132053.623527664540176496.stgit@mhiramat.tok.corp.google.com/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-04-22 09:26:37 +09:00
Linus Torvalds
cb30bf881c tracing updates for v7.1:
- Fix printf format warning for bprintf
 
   sunrpc uses a trace_printk() that triggers a printf warning during the
   compile. Move the __printf() attribute around for when debugging is not
   enabled the warning will go away.
 
 - Remove redundant check for EVENT_FILE_FL_FREED in event_filter_write()
 
   The FREED flag is checked in the call to event_file_file() and then
   checked again right afterward, which is unneeded.
 
 - Clean up event_file_file() and event_file_data() helpers
 
   These helper functions played a different role in the past, but now with
   eventfs, the READ_ONCE() isn't needed. Simplify the code a bit and also
   add a warning to event_file_data() if the file or its data is not present.
 
 - Remove updating file->private_data in tracing open
 
   All access to the file private data is handled by the helper functions,
   which do not use file->private_data. Stop updating it on open.
 
 - Show ENUM names in function arguments via BTF in function tracing
 
   When showing the function arguments when func-args option is set for
   function tracing, if one of the arguments is found to be an enum, show the
   name of the enum instead of its number.
 
 - Add new trace_call__##name() API for tracepoints
 
   Tracepoints are enabled via static_branch() blocks, where when not
   enabled, there's only a nop that is in the code where the execution will
   just skip over it. When tracing is enabled, the nop is converted to a
   direct jump to the tracepoint code. Sometimes more calculations are
   required to be performed to update the parameters of the tracepoint. In
   this case, trace_##name##_enabled() is called which is a static_branch()
   that gets enabled only when the tracepoint is enabled. This allows the
   extra calculations to also be skipped by the nop:
 
   if (trace_foo_enabled()) {
       x = bar();
       trace_foo(x);
   }
 
   Where the x=bar() is only performed when foo is enabled. The problem with
   this approach is that there's now two static_branch() calls. One for
   checking if the tracepoint is enabled, and then again to know if the
   tracepoint should be called. The second one is redundant.
 
   Introduce trace_call__foo() that will call the foo() tracepoint directly
   without doing a static_branch():
 
   if (trace_foo_enabled()) {
       x = bar();
       trace_call__foo();
   }
 
 - Update various locations to use the new trace_call__##name() API
 
 - Move snapshot code out of trace.c
 
   Cleaning up trace.c to not be a "dump all", move the snapshot code out of
   it and into a new trace_snapshot.c file.
 
 - Clean up some "%*.s" to "%*s"
 
 - Allow boot kernel command line options to be called multiple times
 
   Have options like:
 
     ftrace_filter=foo ftrace_filter=bar ftrace_filter=zoo
 
   Equal to:
 
     ftrace_filter=foo,bar,zoo
 
 - Fix ipi_raise event CPU field to be a CPU field
 
   The ipi_raise target_cpus field is defined as a __bitmask(). There is now a
   __cpumask() field definition. Update the field to use that.
 
 - Have hist_field_name() use a snprintf() and not a series of strcat()
 
   It's safer to use snprintf() that a series of strcat().
 
 - Fix tracepoint regfunc balancing
 
   A tracepoint can define a "reg" and "unreg" function that gets called
   before the tracepoint is enabled, and after it is disabled respectively.
   But on error, after the "reg" func is called and the tracepoint is not
   enabled, the "unreg" function is not called to tear down what the "reg"
   function performed.
 
 - Fix output that shows what histograms are enabled
 
   Event variables are displayed incorrectly in the histogram output.
 
   Instead of "sched.sched_wakeup.$var", it is showing
   "$sched.sched_wakeup.var" where the '$' is in the incorrect location.
 
 - Some other simple cleanups.
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Merge tag 'trace-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing updates from Steven Rostedt:

 - Fix printf format warning for bprintf

   sunrpc uses a trace_printk() that triggers a printf warning during
   the compile. Move the __printf() attribute around for when debugging
   is not enabled the warning will go away

 - Remove redundant check for EVENT_FILE_FL_FREED in
   event_filter_write()

   The FREED flag is checked in the call to event_file_file() and then
   checked again right afterward, which is unneeded

 - Clean up event_file_file() and event_file_data() helpers

   These helper functions played a different role in the past, but now
   with eventfs, the READ_ONCE() isn't needed. Simplify the code a bit
   and also add a warning to event_file_data() if the file or its data
   is not present

 - Remove updating file->private_data in tracing open

   All access to the file private data is handled by the helper
   functions, which do not use file->private_data. Stop updating it on
   open

 - Show ENUM names in function arguments via BTF in function tracing

   When showing the function arguments when func-args option is set for
   function tracing, if one of the arguments is found to be an enum,
   show the name of the enum instead of its number

 - Add new trace_call__##name() API for tracepoints

   Tracepoints are enabled via static_branch() blocks, where when not
   enabled, there's only a nop that is in the code where the execution
   will just skip over it. When tracing is enabled, the nop is converted
   to a direct jump to the tracepoint code. Sometimes more calculations
   are required to be performed to update the parameters of the
   tracepoint. In this case, trace_##name##_enabled() is called which is
   a static_branch() that gets enabled only when the tracepoint is
   enabled. This allows the extra calculations to also be skipped by the
   nop:

	if (trace_foo_enabled()) {
		x = bar();
		trace_foo(x);
	}

   Where the x=bar() is only performed when foo is enabled. The problem
   with this approach is that there's now two static_branch() calls. One
   for checking if the tracepoint is enabled, and then again to know if
   the tracepoint should be called. The second one is redundant

   Introduce trace_call__foo() that will call the foo() tracepoint
   directly without doing a static_branch():

	if (trace_foo_enabled()) {
		x = bar();
		trace_call__foo();
	}

 - Update various locations to use the new trace_call__##name() API

 - Move snapshot code out of trace.c

   Cleaning up trace.c to not be a "dump all", move the snapshot code
   out of it and into a new trace_snapshot.c file

 - Clean up some "%*.s" to "%*s"

 - Allow boot kernel command line options to be called multiple times

   Have options like:

	ftrace_filter=foo ftrace_filter=bar ftrace_filter=zoo

   Equal to:

	ftrace_filter=foo,bar,zoo

 - Fix ipi_raise event CPU field to be a CPU field

   The ipi_raise target_cpus field is defined as a __bitmask(). There is
   now a __cpumask() field definition. Update the field to use that

 - Have hist_field_name() use a snprintf() and not a series of strcat()

   It's safer to use snprintf() that a series of strcat()

 - Fix tracepoint regfunc balancing

   A tracepoint can define a "reg" and "unreg" function that gets called
   before the tracepoint is enabled, and after it is disabled
   respectively. But on error, after the "reg" func is called and the
   tracepoint is not enabled, the "unreg" function is not called to tear
   down what the "reg" function performed

 - Fix output that shows what histograms are enabled

   Event variables are displayed incorrectly in the histogram output

   Instead of "sched.sched_wakeup.$var", it is showing
   "$sched.sched_wakeup.var" where the '$' is in the incorrect location

 - Some other simple cleanups

* tag 'trace-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (24 commits)
  selftests/ftrace: Add test case for fully-qualified variable references
  tracing: Fix fully-qualified variable reference printing in histograms
  tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func()
  tracing: Rebuild full_name on each hist_field_name() call
  tracing: Report ipi_raise target CPUs as cpumask
  tracing: Remove duplicate latency_fsnotify() stub
  tracing: Preserve repeated trace_trigger boot parameters
  tracing: Append repeated boot-time tracing parameters
  tracing: Remove spurious default precision from show_event_trigger/filter formats
  cpufreq: Use trace_call__##name() at guarded tracepoint call sites
  tracing: Remove tracing_alloc_snapshot() when snapshot isn't defined
  tracing: Move snapshot code out of trace.c and into trace_snapshot.c
  mm: damon: Use trace_call__##name() at guarded tracepoint call sites
  btrfs: Use trace_call__##name() at guarded tracepoint call sites
  spi: Use trace_call__##name() at guarded tracepoint call sites
  i2c: Use trace_call__##name() at guarded tracepoint call sites
  kernel: Use trace_call__##name() at guarded tracepoint call sites
  tracepoint: Add trace_call__##name() API
  tracing: trace_mmap.h: fix a kernel-doc warning
  tracing: Pretty-print enum parameters in function arguments
  ...
2026-04-17 09:43:12 -07:00
Linus Torvalds
01f492e181 Arm:
- Add support for tracing in the standalone EL2 hypervisor code, which
   should help both debugging and performance analysis.  This uses the
   new infrastructure for 'remote' trace buffers that can be exposed
   by non-kernel entities such as firmware, and which came through the
   tracing tree.
 
 - Add support for GICv5 Per Processor Interrupts (PPIs), as the starting
   point for supporting the new GIC architecture in KVM.
 
 - Finally add support for pKVM protected guests, where pages are unmapped
   from the host as they are faulted into the guest and can be shared back
   from the guest using pKVM hypercalls.  Protected guests are created
   using a new machine type identifier.  As the elusive guestmem has not
   yet delivered on its promises, anonymous memory is also supported.
 
   This is only a first step towards full isolation from the host; for
   example, the CPU register state and DMA accesses are not yet isolated.
   Because this does not really yet bring fully what it promises, it is
   hidden behind CONFIG_ARM_PKVM_GUEST + 'kvm-arm.mode=protected', and
   also triggers TAINT_USER when a VM is created.  Caveat emptor.
 
 - Rework the dreaded user_mem_abort() function to make it more
   maintainable, reducing the amount of state being exposed to the
   various helpers and rendering a substantial amount of state immutable.
 
 - Expand the Stage-2 page table dumper to support NV shadow page tables
   on a per-VM basis.
 
 - Tidy up the pKVM PSCI proxy code to be slightly less hard to follow.
 
 - Fix both SPE and TRBE in non-VHE configurations so that they do not
   generate spurious, out of context table walks that ultimately lead
   to very bad HW lockups.
 
 - A small set of patches fixing the Stage-2 MMU freeing in error cases.
 
 - Tighten-up accepted SMC immediate value to be only #0 for host
   SMCCC calls.
 
 - The usual cleanups and other selftest churn.
 
 LoongArch:
 
 - Use CSR_CRMD_PLV for kvm_arch_vcpu_in_kernel().
 
 - Add DMSINTC irqchip in kernel support.
 
 RISC-V:
 
 - Fix steal time shared memory alignment checks
 
 - Fix vector context allocation leak
 
 - Fix array out-of-bounds in pmu_ctr_read() and pmu_fw_ctr_read_hi()
 
 - Fix double-free of sdata in kvm_pmu_clear_snapshot_area()
 
 - Fix integer overflow in kvm_pmu_validate_counter_mask()
 
 - Fix shift-out-of-bounds in make_xfence_request()
 
 - Fix lost write protection on huge pages during dirty logging
 
 - Split huge pages during fault handling for dirty logging
 
 - Skip CSR restore if VCPU is reloaded on the same core
 
 - Implement kvm_arch_has_default_irqchip() for KVM selftests
 
 - Factored-out ISA checks into separate sources
 
 - Added hideleg to struct kvm_vcpu_config
 
 - Factored-out VCPU config into separate sources
 
 - Support configuration of per-VM HGATP mode from KVM user space
 
 s390:
 
 - Support for ESA (31-bit) guests inside nested hypervisors.
 
 - Remove restriction on memslot alignment, which is not needed anymore with
   the new gmap code.
 
 - Fix LPSW/E to update the bear (which of course is the breaking event
   address register).
 
 x86:
 
 - Shut up various UBSAN warnings on reading module parameter before they
   were initialized.
 
 - Don't zero-allocate page tables that are used for splitting hugepages in
   the TDP MMU, as KVM is guaranteed to set all SPTEs in the page table and
   thus write all bytes.
 
 - As an optimization, bail early when trying to unsync 4KiB mappings if the
   target gfn can just be mapped with a 2MiB hugepage.
 
 x86 generic:
 
 - Copy single-chunk MMIO write values into struct kvm_vcpu (more precisely
   struct kvm_mmio_fragment) to fix use-after-free stack bugs where KVM
   would dereference stack pointer after an exit to userspace.
 
 - Clean up and comment the emulated MMIO code to try to make it easier to
   maintain (not necessarily "easy", but "easier").
 
 - Move VMXON+VMXOFF and EFER.SVME toggling out of KVM (not *all* of VMX
   and SVM enabling) as it is needed for trusted I/O.
 
 - Advertise support for AVX512 Bit Matrix Multiply (BMM) instructions
 
 - Immediately fail the build if a required #define is missing in one of
   KVM's headers that is included multiple times.
 
 - Reject SET_GUEST_DEBUG with -EBUSY if there's an already injected
   exception, mostly to prevent syzkaller from abusing the uAPI to
   trigger WARNs, but also because it can help prevent userspace from
   unintentionally crashing the VM.
 
 - Exempt SMM from CPUID faulting on Intel, as per the spec.
 
 - Misc hardening and cleanup changes.
 
 x86 (AMD):
 
 - Fix and optimize IRQ window inhibit handling for AVIC; make it per-vCPU
   so that KVM doesn't prematurely re-enable AVIC if multiple
   vCPUs have to-be-injected IRQs.
 
 - Clean up and optimize the OSVW handling, avoiding a bug in which KVM would
   overwrite state when enabling virtualization on multiple CPUs in parallel.
   This should not be a problem because OSVW should usually be the same for
   all CPUs.
 
 - Drop a WARN in KVM_MEMORY_ENCRYPT_REG_REGION where KVM complains about a
   "too large" size based purely on user input.
 
 - Clean up and harden the pinning code for KVM_MEMORY_ENCRYPT_REG_REGION.
 
 - Disallow synchronizing a VMSA of an already-launched/encrypted vCPU, as
   doing so for an SNP guest will crash the host due to an RMP violation
   page fault.
 
 - Overhaul KVM's APIs for detecting SEV+ guests so that VM-scoped queries
   are required to hold kvm->lock, and enforce it by lockdep.  Fix various
   bugs where sev_guest() was not ensured to be stable for the whole
   duration of a function or ioctl.
 
 - Convert a pile of kvm->lock SEV code to guard().
 
 - Play nicer with userspace that does not enable KVM_CAP_EXCEPTION_PAYLOAD,
   for which KVM needs to set CR2 and DR6 as a response to ioctls such as
   KVM_GET_VCPU_EVENTS (even if the payload would end up in EXITINFO2
   rather than CR2, for example).  Only set CR2 and DR6 when consumption of
   the payload is imminent, but on the other hand force delivery of the
   payload in all paths where userspace retrieves CR2 or DR6.
 
 - Use vcpu->arch.cr2 when updating vmcb12's CR2 on nested #VMEXIT instead
   of vmcb02->save.cr2.  The value is out of sync after a save/restore
   or after a #PF is injected into L2.
 
 - Fix a class of nSVM bugs where some fields written by the CPU are not
   synchronized from vmcb02 to cached vmcb12 after VMRUN, and so are not
   up-to-date when saved by KVM_GET_NESTED_STATE.
 
 - Fix a class of bugs where the ordering between KVM_SET_NESTED_STATE and
   KVM_SET_{S}REGS could cause vmcb02 to be incorrectly initialized after
   save+restore.
 
 - Add a variety of missing nSVM consistency checks.
 
 - Fix several bugs where KVM failed to correctly update VMCB fields on
   nested #VMEXIT.
 
 - Fix several bugs where KVM failed to correctly synthesize #UD or #GP for
   SVM-related instructions.
 
 - Add support for save+restore of virtualized LBRs (on SVM).
 
 - Refactor various helpers and macros to improve clarity and (hopefully)
   make the code easier to maintain.
 
 - Aggressively sanitize fields when copying from vmcb12, to guard against
   unintentionally allowing L1 to utilize yet-to-be-defined features.
 
 - Fix several bugs where KVM botched rAX legality checks when emulating SVM
   instructions.  There are remaining issues in that KVM doesn't handle size
   prefix overrides for 64-bit guests.
 
 - Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails instead of
   somewhat arbitrarily synthesizing #GP (i.e. don't double down on AMD's
   architectural but sketchy behavior of generating #GP for "unsupported"
   addresses).
 
 - Cache all used vmcb12 fields to further harden against TOCTOU bugs.
 
 x86 (Intel):
 
 - Drop obsolete branch hint prefixes from the VMX instruction macros.
 
 - Use ASM_INPUT_RM() in __vmcs_writel() to coerce clang into using a
   register input when appropriate.
 
 - Code cleanups.
 
 guest_memfd:
 
 - Don't mark guest_memfd folios as accessed, as guest_memfd doesn't support
   reclaim, the memory is unevictable, and there is no storage to write
   back to.
 
 LoongArch selftests:
 
 - Add KVM PMU test cases
 
 s390 selftests:
 
 - Enable more memory selftests.
 
 x86 selftests:
 
 - Add support for Hygon CPUs in KVM selftests.
 
 - Fix a bug in the MSR test where it would get false failures on AMD/Hygon
   CPUs with exactly one of RDPID or RDTSCP.
 
 - Add an MADV_COLLAPSE testcase for guest_memfd as a regression test for a
   bug where the kernel would attempt to collapse guest_memfd folios against
   KVM's will.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm updates from Paolo Bonzini:
 "Arm:

   - Add support for tracing in the standalone EL2 hypervisor code,
     which should help both debugging and performance analysis. This
     uses the new infrastructure for 'remote' trace buffers that can be
     exposed by non-kernel entities such as firmware, and which came
     through the tracing tree

   - Add support for GICv5 Per Processor Interrupts (PPIs), as the
     starting point for supporting the new GIC architecture in KVM

   - Finally add support for pKVM protected guests, where pages are
     unmapped from the host as they are faulted into the guest and can
     be shared back from the guest using pKVM hypercalls. Protected
     guests are created using a new machine type identifier. As the
     elusive guestmem has not yet delivered on its promises, anonymous
     memory is also supported

     This is only a first step towards full isolation from the host; for
     example, the CPU register state and DMA accesses are not yet
     isolated. Because this does not really yet bring fully what it
     promises, it is hidden behind CONFIG_ARM_PKVM_GUEST +
     'kvm-arm.mode=protected', and also triggers TAINT_USER when a VM is
     created. Caveat emptor

   - Rework the dreaded user_mem_abort() function to make it more
     maintainable, reducing the amount of state being exposed to the
     various helpers and rendering a substantial amount of state
     immutable

   - Expand the Stage-2 page table dumper to support NV shadow page
     tables on a per-VM basis

   - Tidy up the pKVM PSCI proxy code to be slightly less hard to
     follow

   - Fix both SPE and TRBE in non-VHE configurations so that they do not
     generate spurious, out of context table walks that ultimately lead
     to very bad HW lockups

   - A small set of patches fixing the Stage-2 MMU freeing in error
     cases

   - Tighten-up accepted SMC immediate value to be only #0 for host
     SMCCC calls

   - The usual cleanups and other selftest churn

  LoongArch:

   - Use CSR_CRMD_PLV for kvm_arch_vcpu_in_kernel()

   - Add DMSINTC irqchip in kernel support

  RISC-V:

   - Fix steal time shared memory alignment checks

   - Fix vector context allocation leak

   - Fix array out-of-bounds in pmu_ctr_read() and pmu_fw_ctr_read_hi()

   - Fix double-free of sdata in kvm_pmu_clear_snapshot_area()

   - Fix integer overflow in kvm_pmu_validate_counter_mask()

   - Fix shift-out-of-bounds in make_xfence_request()

   - Fix lost write protection on huge pages during dirty logging

   - Split huge pages during fault handling for dirty logging

   - Skip CSR restore if VCPU is reloaded on the same core

   - Implement kvm_arch_has_default_irqchip() for KVM selftests

   - Factored-out ISA checks into separate sources

   - Added hideleg to struct kvm_vcpu_config

   - Factored-out VCPU config into separate sources

   - Support configuration of per-VM HGATP mode from KVM user space

  s390:

   - Support for ESA (31-bit) guests inside nested hypervisors

   - Remove restriction on memslot alignment, which is not needed
     anymore with the new gmap code

   - Fix LPSW/E to update the bear (which of course is the breaking
     event address register)

  x86:

   - Shut up various UBSAN warnings on reading module parameter before
     they were initialized

   - Don't zero-allocate page tables that are used for splitting
     hugepages in the TDP MMU, as KVM is guaranteed to set all SPTEs in
     the page table and thus write all bytes

   - As an optimization, bail early when trying to unsync 4KiB mappings
     if the target gfn can just be mapped with a 2MiB hugepage

  x86 generic:

   - Copy single-chunk MMIO write values into struct kvm_vcpu (more
     precisely struct kvm_mmio_fragment) to fix use-after-free stack
     bugs where KVM would dereference stack pointer after an exit to
     userspace

   - Clean up and comment the emulated MMIO code to try to make it
     easier to maintain (not necessarily "easy", but "easier")

   - Move VMXON+VMXOFF and EFER.SVME toggling out of KVM (not *all* of
     VMX and SVM enabling) as it is needed for trusted I/O

   - Advertise support for AVX512 Bit Matrix Multiply (BMM) instructions

   - Immediately fail the build if a required #define is missing in one
     of KVM's headers that is included multiple times

   - Reject SET_GUEST_DEBUG with -EBUSY if there's an already injected
     exception, mostly to prevent syzkaller from abusing the uAPI to
     trigger WARNs, but also because it can help prevent userspace from
     unintentionally crashing the VM

   - Exempt SMM from CPUID faulting on Intel, as per the spec

   - Misc hardening and cleanup changes

  x86 (AMD):

   - Fix and optimize IRQ window inhibit handling for AVIC; make it
     per-vCPU so that KVM doesn't prematurely re-enable AVIC if multiple
     vCPUs have to-be-injected IRQs

   - Clean up and optimize the OSVW handling, avoiding a bug in which
     KVM would overwrite state when enabling virtualization on multiple
     CPUs in parallel. This should not be a problem because OSVW should
     usually be the same for all CPUs

   - Drop a WARN in KVM_MEMORY_ENCRYPT_REG_REGION where KVM complains
     about a "too large" size based purely on user input

   - Clean up and harden the pinning code for KVM_MEMORY_ENCRYPT_REG_REGION

   - Disallow synchronizing a VMSA of an already-launched/encrypted
     vCPU, as doing so for an SNP guest will crash the host due to an
     RMP violation page fault

   - Overhaul KVM's APIs for detecting SEV+ guests so that VM-scoped
     queries are required to hold kvm->lock, and enforce it by lockdep.
     Fix various bugs where sev_guest() was not ensured to be stable for
     the whole duration of a function or ioctl

   - Convert a pile of kvm->lock SEV code to guard()

   - Play nicer with userspace that does not enable
     KVM_CAP_EXCEPTION_PAYLOAD, for which KVM needs to set CR2 and DR6
     as a response to ioctls such as KVM_GET_VCPU_EVENTS (even if the
     payload would end up in EXITINFO2 rather than CR2, for example).
     Only set CR2 and DR6 when consumption of the payload is imminent,
     but on the other hand force delivery of the payload in all paths
     where userspace retrieves CR2 or DR6

   - Use vcpu->arch.cr2 when updating vmcb12's CR2 on nested #VMEXIT
     instead of vmcb02->save.cr2. The value is out of sync after a
     save/restore or after a #PF is injected into L2

   - Fix a class of nSVM bugs where some fields written by the CPU are
     not synchronized from vmcb02 to cached vmcb12 after VMRUN, and so
     are not up-to-date when saved by KVM_GET_NESTED_STATE

   - Fix a class of bugs where the ordering between KVM_SET_NESTED_STATE
     and KVM_SET_{S}REGS could cause vmcb02 to be incorrectly
     initialized after save+restore

   - Add a variety of missing nSVM consistency checks

   - Fix several bugs where KVM failed to correctly update VMCB fields
     on nested #VMEXIT

   - Fix several bugs where KVM failed to correctly synthesize #UD or
     #GP for SVM-related instructions

   - Add support for save+restore of virtualized LBRs (on SVM)

   - Refactor various helpers and macros to improve clarity and
     (hopefully) make the code easier to maintain

   - Aggressively sanitize fields when copying from vmcb12, to guard
     against unintentionally allowing L1 to utilize yet-to-be-defined
     features

   - Fix several bugs where KVM botched rAX legality checks when
     emulating SVM instructions. There are remaining issues in that KVM
     doesn't handle size prefix overrides for 64-bit guests

   - Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails
     instead of somewhat arbitrarily synthesizing #GP (i.e. don't double
     down on AMD's architectural but sketchy behavior of generating #GP
     for "unsupported" addresses)

   - Cache all used vmcb12 fields to further harden against TOCTOU bugs

  x86 (Intel):

   - Drop obsolete branch hint prefixes from the VMX instruction macros

   - Use ASM_INPUT_RM() in __vmcs_writel() to coerce clang into using a
     register input when appropriate

   - Code cleanups

  guest_memfd:

   - Don't mark guest_memfd folios as accessed, as guest_memfd doesn't
     support reclaim, the memory is unevictable, and there is no storage
     to write back to

  LoongArch selftests:

   - Add KVM PMU test cases

  s390 selftests:

   - Enable more memory selftests

  x86 selftests:

   - Add support for Hygon CPUs in KVM selftests

   - Fix a bug in the MSR test where it would get false failures on
     AMD/Hygon CPUs with exactly one of RDPID or RDTSCP

   - Add an MADV_COLLAPSE testcase for guest_memfd as a regression test
     for a bug where the kernel would attempt to collapse guest_memfd
     folios against KVM's will"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (373 commits)
  KVM: x86: use inlines instead of macros for is_sev_*guest
  x86/virt: Treat SVM as unsupported when running as an SEV+ guest
  KVM: SEV: Goto an existing error label if charging misc_cg for an ASID fails
  KVM: SVM: Move lock-protected allocation of SEV ASID into a separate helper
  KVM: SEV: use mutex guard in snp_handle_guest_req()
  KVM: SEV: use mutex guard in sev_mem_enc_unregister_region()
  KVM: SEV: use mutex guard in sev_mem_enc_ioctl()
  KVM: SEV: use mutex guard in snp_launch_update()
  KVM: SEV: Assert that kvm->lock is held when querying SEV+ support
  KVM: SEV: Document that checking for SEV+ guests when reclaiming memory is "safe"
  KVM: SEV: Hide "struct kvm_sev_info" behind CONFIG_KVM_AMD_SEV=y
  KVM: SEV: WARN on unhandled VM type when initializing VM
  KVM: LoongArch: selftests: Add PMU overflow interrupt test
  KVM: LoongArch: selftests: Add basic PMU event counting test
  KVM: LoongArch: selftests: Add cpucfg read/write helpers
  LoongArch: KVM: Add DMSINTC inject msi to vCPU
  LoongArch: KVM: Add DMSINTC device support
  LoongArch: KVM: Make vcpu_is_preempted() as a macro rather than function
  LoongArch: KVM: Move host CSR_GSTAT save and restore in context switch
  LoongArch: KVM: Move host CSR_EENTRY save and restore in context switch
  ...
2026-04-17 07:18:03 -07:00
Linus Torvalds
e4bf304f00 ring-buffer updates for 7.1:
- Add remote buffers for pKVM
 
   pKVM has a hypervisor component that is used to protect the guest from the
   host kernel. This hypervisor is a black box to the kernel as the kernel is
   to user space. The remote buffers are used to have a memory mapping
   between the hypervisor and the kernel where kernel may send commands to
   enable tracing within the hypervisor. Then the kernel will read this
   memory mapping just like user space can read the memory mapped ring buffer
   of the kernel tracing system.
 
   Since the hypervisor only has a single context, it doesn't need to worry
   about races between normal context, interrupt context and NMIs like the
   kernel does. The ring buffer it uses doesn't need to be as complex. The
   remote buffers are a simple version of the ring buffer that works in a
   single context. They are still per-CPU and use sub buffers. The data
   layout is the same as the kernel's ring buffer to share the same parsing.
 
   Currently, only ARM64 implements pKVM, but there's work to implement it
   also in x86. The remote buffer code is separated out from the ARM
   implementation so that it can be used in the future by x86.
 
   The ARM64 updates for pKVM is in the ARM/KVM tree and it merged in the
   remote buffers of this tree.
 
 - Merge commit f35dbac694 ("ring-buffer: Fix to update per-subbuf entries of persistent ring buffer")`
 
   A fix was merged upstream that some new changes depended on. The upstream
   commit was merged into the ring buffer branch to fulfil the dependency.
 
 - Make the backup instance non reusable
 
   The backup instance is a copy of the persistent ring buffer so that the
   persistent ring buffer could start recording again without using the data
   from the previous boot. The backup isn't for normal tracing. It is made
   read-only, and after it is consumed, it is automatically removed.
 
 - Have backup copy persistent instance before it starts recording
 
   To allow the persistent ring buffer to start recording from the kernel
   command line commands, move the copy of the backup instance to before the
   the command line options start recording.
 
 - Report header_page overwrite field as "char" and not "int'
 
   The rust parser of the header_page file was triggering a warning when it
   defined the overwrite variable as "int" but it was only a single byte in
   size.
 
 - Fix memory barriers for the trace_buffer CPU mask
 
   When a CPU comes online, the bit is set to allow readers to know that the
   CPU buffer is allocated. The bit is set after the allocation is done, and
   a smp_wmb() is performed after the allocation and before the setting of
   the bit. But instead of adding a smp_rmb() to all readers, since once a
   buffer is created for a CPU it is not deleted if that CPU goes offline, so
   this allocation is almost always done at boot up before any readers exist.
 
   If for the unlikely case where a CPU comes online for the first time after
   the system boot has finished, send an IPI to all CPUs to force the
   smp_rmb() for each CPU.
 
 - Show clock function being used in debugging ring buffer data
 
   When the ring buffer checks are enabled and the ring buffer detects an
   inconsistency in the times of the invents, print out the clock being used
   when the error occurred. There was a very hard to hit bug that would
   happen every so often and it ended up being only triggered when the jiffies
   clock was being used. If the bug showed the clock being used, it would
   have been much easier to find the problem (which was an internal function
   was being traced which caused the clock accounting to go off).
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Merge tag 'trace-ringbuffer-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ring-buffer updates from Steven Rostedt:

 - Add remote buffers for pKVM

   pKVM has a hypervisor component that is used to protect the guest
   from the host kernel. This hypervisor is a black box to the kernel as
   the kernel is to user space. The remote buffers are used to have a
   memory mapping between the hypervisor and the kernel where kernel may
   send commands to enable tracing within the hypervisor. Then the
   kernel will read this memory mapping just like user space can read
   the memory mapped ring buffer of the kernel tracing system.

   Since the hypervisor only has a single context, it doesn't need to
   worry about races between normal context, interrupt context and NMIs
   like the kernel does. The ring buffer it uses doesn't need to be as
   complex. The remote buffers are a simple version of the ring buffer
   that works in a single context. They are still per-CPU and use sub
   buffers. The data layout is the same as the kernel's ring buffer to
   share the same parsing.

   Currently, only ARM64 implements pKVM, but there's work to implement
   it also in x86. The remote buffer code is separated out from the ARM
   implementation so that it can be used in the future by x86.

   The ARM64 updates for pKVM is in the ARM/KVM tree and it merged in
   the remote buffers of this tree.

 - Make the backup instance non reusable

   The backup instance is a copy of the persistent ring buffer so that
   the persistent ring buffer could start recording again without using
   the data from the previous boot. The backup isn't for normal tracing.
   It is made read-only, and after it is consumed, it is automatically
   removed.

 - Have backup copy persistent instance before it starts recording

   To allow the persistent ring buffer to start recording from the
   kernel command line commands, move the copy of the backup instance to
   before the the command line options start recording.

 - Report header_page overwrite field as "char" and not "int'

   The rust parser of the header_page file was triggering a warning when
   it defined the overwrite variable as "int" but it was only a single
   byte in size.

 - Fix memory barriers for the trace_buffer CPU mask

   When a CPU comes online, the bit is set to allow readers to know that
   the CPU buffer is allocated. The bit is set after the allocation is
   done, and a smp_wmb() is performed after the allocation and before
   the setting of the bit. But instead of adding a smp_rmb() to all
   readers, since once a buffer is created for a CPU it is not deleted
   if that CPU goes offline, so this allocation is almost always done at
   boot up before any readers exist.

   If for the unlikely case where a CPU comes online for the first time
   after the system boot has finished, send an IPI to all CPUs to force
   the smp_rmb() for each CPU.

 - Show clock function being used in debugging ring buffer data

   When the ring buffer checks are enabled and the ring buffer detects
   an inconsistency in the times of the invents, print out the clock
   being used when the error occurred. There was a very hard to hit bug
   that would happen every so often and it ended up being only triggered
   when the jiffies clock was being used. If the bug showed the clock
   being used, it would have been much easier to find the problem (which
   was an internal function was being traced which caused the clock
   accounting to go off).

* tag 'trace-ringbuffer-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits)
  ring-buffer: Prevent off-by-one array access in ring_buffer_desc_page()
  ring-buffer: Report header_page overwrite as char
  tracing: Allow backup to save persistent ring buffer before it starts
  tracing/Documentation: Add a section about backup instance
  tracing: Remove the backup instance automatically after read
  tracing: Make the backup instance non-reusable
  ring-buffer: Enforce read ordering of trace_buffer cpumask and buffers
  ring-buffer: Show what clock function is used on timestamp errors
  tracing: Check for undefined symbols in simple_ring_buffer
  tracing: load/unload page callbacks for simple_ring_buffer
  Documentation: tracing: Add tracing remotes
  tracing: selftests: Add trace remote tests
  tracing: Add a trace remote module for testing
  tracing: Introduce simple_ring_buffer
  ring-buffer: Export buffer_data_page and macros
  tracing: Add helpers to create trace remote events
  tracing: Add events/ root files to trace remotes
  tracing: Add events to trace remotes
  tracing: Add init callback to trace remotes
  tracing: Add non-consuming read to trace remotes
  ...
2026-04-15 15:59:46 -07:00
Tom Zanussi
621a59d8fc selftests/ftrace: Add test case for fully-qualified variable references
This test adds a variable (ts0) to two events (sched_waking and
sched_wakeup) and uses a fully-qualified variable reference to expicitly
choose a particular one (sched_wakeup.$ts0) when calculating the wakeup
latency.

Link: https://patch.msgid.link/ce9d96aeb84b2d40bd469fe9a346e225442873b1.1776112478.git.zanussi@kernel.org
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-04-14 05:28:38 -04:00
Cao Ruichuang
f8e0a5a174 selftests/ftrace: Quote check_requires comparisons
check_requires() compares requirement strings that can contain shell
pattern characters such as '[' and ']'. Under /bin/sh, the unquoted
test expressions can emit 'unexpected operator' warnings while parsing
README-backed requirements.

Quote the relevant comparisons and path checks so the helper handles
those patterns without spurious shell warnings.

Validated by rerunning fprobe_syntax_errors.tc and confirming the
previous '/bin/sh: unexpected operator' lines disappear from the
detailed ftracetest log.

Signed-off-by: Cao Ruichuang <create0818@163.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20260408043212.8063-1-create0818@163.com
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2026-04-13 11:05:39 -06:00
Vincent Donnefort
ec07906bdc tracing: selftests: Extend hotplug testing for trace remotes
The hotplug testing only tries reading a trace remote buffer, loaded
before a CPU is offline. Extend this testing to cover:

  * A trace remote buffer loaded after a CPU is offline.
  * A trace remote buffer loaded before a CPU is online.

Because of these added test cases, move the hotplug testing into a
separate hotplug.tc file.

Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260401045100.3394299-3-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-04-02 14:16:09 +01:00
Masami Hiramatsu (Google)
3d0b8e4507 selftests/tracing: Fix to check awk supports non POSIX strtonum()
Check the awk command supports non POSIX strtonum() function in
the trace_marker_raw test case.

Fixes: 37f4660138 ("selftests/tracing: Add basic test for trace_marker_raw file")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/177071726229.2369897.11506524546451139051.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2026-03-31 13:06:24 -06:00
Masami Hiramatsu (Google)
e011853dd7 selftests/tracing: Fix to make --logdir option work again
Since commit a0aa283c53 ("selftest/ftrace: Generalise ftracetest to
use with RV") moved the default LOG_DIR setting after --logdir option
parser, it overwrites the user given LOG_DIR.
This fixes it to check the --logdir option parameter when setting new
default LOG_DIR with a new TOP_DIR.

Fixes: a0aa283c53 ("selftest/ftrace: Generalise ftracetest to use with RV")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Tested-by: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/r/177071725191.2369897.14781037901532893911.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2026-03-31 13:06:18 -06:00
Vincent Donnefort
39d5ca62a3 tracing: selftests: Add hypervisor trace remote tests
Run the trace remote selftests with the trace remote 'hypervisor', This
trace remote is most likely created when the arm64 KVM nVHE/pKVM
hypervisor is in use.

Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://patch.msgid.link/20260309162516.2623589-31-vdonnefort@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-11 08:51:17 +00:00
Vincent Donnefort
0a1b03251d tracing: selftests: Add trace remote tests
Exercise the tracefs interface for trace remote with a set of tests to
check:

  * loading/unloading (unloading.tc)
  * reset (reset.tc)
  * size changes (buffer_size.tc)
  * consuming read (trace_pipe.tc)
  * non-consuming read (trace.tc)

Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: linux-kselftest@vger.kernel.org
Link: https://patch.msgid.link/20260309162516.2623589-16-vdonnefort@google.com
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-03-09 12:33:55 -04:00
Fushuai Wang
6e39903c73 selftests/tracing: Fix test_multiple_writes stall
When /sys/kernel/tracing/buffer_size_kb is less than 12KB,
the test_multiple_writes test will stall and wait for more
input due to insufficient buffer space.

Check current buffer_size_kb value before the test. If it is
less than 12KB, it temporarily increase the buffer to 12KB,
and restore the original value after the tests are completed.

Link: https://lore.kernel.org/r/20260109033620.25727-1-fushuai.wang@linux.dev
Fixes: 37f4660138 ("selftests/tracing: Add basic test for trace_marker_raw file")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2026-01-09 15:49:32 -07:00
Zheng Yejian
0eccd4acd6 selftests/ftrace: Test toplevel-enable for instance
'available_events' is actually not required by
'test.d/event/toplevel-enable.tc' and its Existence has been tested in
'test.d/00basic/basic4.tc'.

So the require of 'available_events' can be dropped and then we can add
'instance' flag to test 'test.d/event/toplevel-enable.tc' for instance.

Test result show as below:
 # ./ftracetest test.d/event/toplevel-enable.tc
 === Ftrace unit tests ===
 [1] event tracing - enable/disable with top level files [PASS]
 [2] (instance)  event tracing - enable/disable with top level files [PASS]

 # of passed:  2
 # of failed:  0
 # of unresolved:  0
 # of untested:  0
 # of unsupported:  0
 # of xfailed:  0
 # of undefined(test bug):  0

Link: https://lore.kernel.org/r/20230509203659.1173917-1-zhengyejian1@huawei.com
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-12-31 12:46:12 -07:00
Yipeng Zou
b889b4fb4c selftests/ftrace: traceonoff_triggers: strip off names
The func_traceonoff_triggers.tc sometimes goes to fail
on my board, Kunpeng-920.

[root@localhost]# ./ftracetest ./test.d/ftrace/func_traceonoff_triggers.tc -l fail.log
=== Ftrace unit tests ===
[1] ftrace - test for function traceon/off triggers     [FAIL]
[2] (instance)  ftrace - test for function traceon/off triggers [UNSUPPORTED]

I look up the log, and it shows that the md5sum is different between csum1 and csum2.

++ cnt=611
++ sleep .1
+++ cnt_trace
+++ grep -v '^#' trace
+++ wc -l
++ cnt2=611
++ '[' 611 -ne 611 ']'
+++ cat tracing_on
++ on=0
++ '[' 0 '!=' 0 ']'
+++ md5sum trace
++ csum1='76896aa74362fff66a6a5f3cf8a8a500  trace'
++ sleep .1
+++ md5sum trace
++ csum2='ee8625a21c058818fc26e45c1ed3f6de  trace'
++ '[' '76896aa74362fff66a6a5f3cf8a8a500  trace' '!=' 'ee8625a21c058818fc26e45c1ed3f6de  trace' ']'
++ fail 'Tracing file is still changing'
++ echo Tracing file is still changing
Tracing file is still changing
++ exit_fail
++ exit 1

So I directly dump the trace file before md5sum, the diff shows that:

[root@localhost]# diff trace_1.log trace_2.log -y --suppress-common-lines
dockerd-12285   [036] d.... 18385.510290: sched_stat | <...>-12285   [036] d.... 18385.510290: sched_stat
dockerd-12285   [036] d.... 18385.510291: sched_swit | <...>-12285   [036] d.... 18385.510291: sched_swit
<...>-740       [044] d.... 18385.602859: sched_stat | kworker/44:1-740 [044] d.... 18385.602859: sched_stat
<...>-740       [044] d.... 18385.602860: sched_swit | kworker/44:1-740 [044] d.... 18385.602860: sched_swit

And we can see that <...> filed be filled with names.

We can strip off the names there to fix that.

After strip off the names:

kworker/u257:0-12 [019] d..2.  2528.758910: sched_stat | -12 [019] d..2.  2528.758910: sched_stat_runtime: comm=k
kworker/u257:0-12 [019] d..2.  2528.758912: sched_swit | -12 [019] d..2.  2528.758912: sched_switch: prev_comm=kw
<idle>-0          [000] d.s5.  2528.762318: sched_waki | -0  [000] d.s5.  2528.762318: sched_waking: comm=sshd pi
<idle>-0          [037] dNh2.  2528.762326: sched_wake | -0  [037] dNh2.  2528.762326: sched_wakeup: comm=sshd pi
<idle>-0          [037] d..2.  2528.762334: sched_swit | -0  [037] d..2.  2528.762334: sched_switch: prev_comm=sw

Link: https://lore.kernel.org/r/20230818013226.2182299-1-zouyipeng@huawei.com
Fixes: d87b29179a ("selftests: ftrace: Use md5sum to take less time of checking logs")
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-12-31 12:45:25 -07:00
Linus Torvalds
0b1b4a3d8e Runtime verifier updates for v6.19:
- Adapt the ftracetest script to be run from a different folder
 
   This uses the already existing OPT_TEST_DIR but extends it further to run
   independent tests, then add an --rv flag to allow using the script for
   testing RV (mostly) independently on ftrace.
 
 - Add basic RV selftests in selftests/verification for more validations
 
   Add more validations for available/enabled monitors and reactors. This
   could have caught the bug introducing kernel panic solved above. Tests use
   ftracetest.
 
 - Convert react() function in reactor to use va_list directly
 
   Use a central helper to handle the variadic arguments. Clean up macros
   and mark functions as static.
 
 - Add lockdep annotations to reactors to have lockdep complain of errors
 
   If the reactors are called from improper context. Useful to develop new
   reactors. This highlights a warning in the panic reactor that is related
   to the printk subsystem and not to RV.
 
 - Convert core RV code to use lock guards and __free helpers
 
   This completely removes goto statements.
 
 - Fix compilation if !CONFIG_RV_REACTORS
 
   Fix the warning by keeping LTL monitor variable as always static.
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Merge tag 'trace-rv-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull runtime verifier updates from Steven Rostedt:

 - Adapt the ftracetest script to be run from a different folder

   This uses the already existing OPT_TEST_DIR but extends it further to
   run independent tests, then add an --rv flag to allow using the
   script for testing RV (mostly) independently on ftrace.

 - Add basic RV selftests in selftests/verification for more validations

   Add more validations for available/enabled monitors and reactors.
   This could have caught the bug introducing kernel panic solved above.
   Tests use ftracetest.

 - Convert react() function in reactor to use va_list directly

   Use a central helper to handle the variadic arguments. Clean up
   macros and mark functions as static.

 - Add lockdep annotations to reactors to have lockdep complain of
   errors

   If the reactors are called from improper context. Useful to develop
   new reactors. This highlights a warning in the panic reactor that is
   related to the printk subsystem and not to RV.

 - Convert core RV code to use lock guards and __free helpers

   This completely removes goto statements.

 - Fix compilation if !CONFIG_RV_REACTORS

   Fix the warning by keeping LTL monitor variable as always static.

* tag 'trace-rv-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  rv: Fix compilation if !CONFIG_RV_REACTORS
  rv: Convert to use __free
  rv: Convert to use lock guard
  rv: Add explicit lockdep context for reactors
  rv: Make rv_reacting_on() static
  rv: Pass va_list to reactors
  selftests/verification: Add initial RV tests
  selftest/ftrace: Generalise ftracetest to use with RV
2025-12-05 10:17:00 -08:00
Linus Torvalds
2488655b2f linux_kselftest-next-6.19-rc1
Adds basic test for trace_marker_raw file to tracing selftest.
 Fixes invalid array access in printf dma_map_benchmark selftest.
 Adds tprobe enable/disable testcase to tracing selftest.
 Updates fprobe selftest for ftrace based fprobe.
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Merge tag 'linux_kselftest-next-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest updates from Shuah Khan:

 - Add basic test for trace_marker_raw file to tracing selftest

 - Fix invalid array access in printf dma_map_benchmark selftest

 - Add tprobe enable/disable testcase to tracing selftest

 - Update fprobe selftest for ftrace based fprobe

* tag 'linux_kselftest-next-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: tracing: Update fprobe selftest for ftrace based fprobe
  selftests: tracing: Add tprobe enable/disable testcase
  selftests/run_kselftest.sh: exit with error if tests fail
  selftests/dma: fix invalid array access in printf
  selftests/tracing: Add basic test for trace_marker_raw file
2025-12-03 15:08:18 -08:00
Masami Hiramatsu (Google)
a2f7990d33 selftests: tracing: Update fprobe selftest for ftrace based fprobe
Since the ftrace fprobe is both fgraph and ftrace based implemented,
the selftest needs to be updated. This does not count the actual
number of lines, but just check the differences.

Link: https://lore.kernel.org/r/176295318112.431538.11780280333728368327.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-11-19 15:55:14 -07:00
Masami Hiramatsu (Google)
a1ca238936 selftests: tracing: Add tprobe enable/disable testcase
Commit 2867495dea ("tracing: tprobe-events: Register tracepoint when
enable tprobe event") caused regression bug and tprobe did not work.
To prevent similar problems, add a testcase which enables/disables a
tprobe and check the results.

Link: https://lore.kernel.org/r/176252610176.214996.3978515319000806265.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-11-19 15:55:08 -07:00
Gabriele Monaco
a0aa283c53 selftest/ftrace: Generalise ftracetest to use with RV
The ftracetest script is a fairly complete test framework for tracefs-like
subsystem, but it can only be used for ftrace selftests.

If OPT_TEST_DIR is provided and includes a function file, use that as
test directory going forward rather than just grabbing tests from it.

Generalise function names like initialize_ftrace to initialize_system.

Add the --rv argument to set up the test for rv, basically changing the
trace directory to $TRACING_DIR/rv and displaying an error if that
cannot be found.

This prepares for rv selftests inclusion.

Link: https://lore.kernel.org/r/20251017115203.140080-2-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
2025-11-11 12:40:15 +01:00
Steven Rostedt
dd4adb986a selftests/tracing: Run sample events to clear page cache events
The tracing selftest "event-filter-function.tc" was failing because it
first runs the "sample_events" function that triggers the kmem_cache_free
event and it looks at what function was used during a call to "ls".

But the first time it calls this, it could trigger events that are used to
pull pages into the page cache.

The rest of the test uses the function it finds during that call to see if
it will be called in subsequent "sample_events" calls. But if there's no
need to pull pages into the page cache, it will not trigger that function
and the test will fail.

Call the "sample_events" twice to trigger all the page cache work before
it calls it to find a function to use in subsequent checks.

Cc: stable@vger.kernel.org
Fixes: eb50d0f250 ("selftests/ftrace: Choose target function for filter test from samples")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-11-10 18:00:07 -07:00
Steven Rostedt
37f4660138 selftests/tracing: Add basic test for trace_marker_raw file
Commit 64cf7d058a ("tracing: Have trace_marker use per-cpu data to read
user space") made an update that fixed both trace_marker and
trace_marker_raw. But the small difference made to trace_marker_raw had a
blatant bug in it that any basic testing would have uncovered.
Unfortunately, the self tests have tests for trace_marker but nothing for
trace_marker_raw which allowed the bug to get upstream.

Add basic selftests to test trace_marker_raw so that this doesn't happen
again.

Link: https://lore.kernel.org/r/20251014145149.3e3c1033@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-11-06 15:23:50 -07:00
Linus Torvalds
b7dbc2e813 Probes updates for v6.17:
- 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
2025-07-30 15:38:01 -07:00
Steven Rostedt
213879061a selftests/tracing: Fix false failure of subsystem event test
The subsystem event test enables all "sched" events and makes sure there's
at least 3 different events in the output. It used to cat the entire trace
file to | wc -l, but on slow machines, that could last a very long time.
To solve that, it was changed to just read the first 100 lines of the
trace file. This can cause false failures as some events repeat so often,
that the 100 lines that are examined could possibly be of only one event.

Instead, create an awk script that looks for 3 different events and will
exit out after it finds them. This will find the 3 events the test looks
for (eventually if it works), and still exit out after the test is
satisfied and not cause slower machines to run forever.

Link: https://lore.kernel.org/r/20250721134212.53c3e140@batman.local.home
Reported-by: Tengda Wu <wutengda@huaweicloud.com>
Closes: https://lore.kernel.org/all/20250710130134.591066-1-wutengda@huaweicloud.com/
Fixes: 1a4ea83a6e ("selftests/ftrace: Limit length in subsystem-enable tests")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-07-24 15:52:20 -06:00
Masami Hiramatsu (Google)
a089bb2822 selftests: tracing: Use mutex_unlock for testing glob filter
Since commit c5b6ababd2 ("locking/mutex: implement
mutex_trylock_nested") makes mutex_trylock() as an inlined
function if CONFIG_DEBUG_LOCK_ALLOC=y, we can not use
mutex_trylock() for testing the glob filter of ftrace.

Use mutex_unlock instead.

Link: https://lore.kernel.org/r/175151680309.2149615.9795104805153538717.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-07-07 15:34:10 -06:00
Masami Hiramatsu (Google)
434f6703ce selftests: tracing: Enable fprobe events before checking enable_functions
Since the fprobe is not registered before enabling the fprobe events,
enable_functions is also empty before enabling it. Thus the tests
which checking enable_functions must ensure the event is enabled before
testing the enable_functions.

Link: https://lore.kernel.org/all/174343538009.843280.6583146613234713007.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2025-07-02 09:45:21 +09:00
Ayush Jain
ab4b00407d selftests/ftrace: Convert poll to a gen_file
Poll program is a helper to ftracetest, thus make it a
generic file and remove it from being run as a test.

Currently when executing tests using
    $ make run_tests
      CC       poll
    TAP version 13
    1..2
    # timeout set to 0
    # selftests: ftrace: poll
    # Error: Polling file is not specified
    not ok 1 selftests: ftrace: poll # exit=255

Fix this by using TEST_GEN_FILES to build the 'poll' binary as a helper
rather than as a test.

Fixes: 80c3e28528 ("selftests/tracing: Add hist poll() support test")

Link: https://lore.kernel.org/r/20250409044632.363285-1-Ayush.jain3@amd.com
Signed-off-by: Ayush Jain <Ayush.jain3@amd.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-05-09 12:43:10 -06:00
Linus Torvalds
fa6ad96dca tracing fixes for v6.15
- Initialize hash variables in ftrace subops logic
 
   The fix that simplified the ftrace subops logic opened a path where some
   variables could be used without being initialized, and done subtly where
   the compiler did not catch it. Initialize those variables to the
   EMPTY_HASH, which is the default hash.
 
 - Reinitialize the hash pointers after they are freed
 
   Some of the hash pointers in the subop logic were freed but may still be
   referenced later. To prevent use-after-free bugs, initialize them back to
   the EMPTY_HASH.
 
 - Free the ftrace hashes when they are replaced
 
   The fix that simplified the subops logic updated some hash pointers, but
   left the original hash that they were pointing to where they are no longer
   used. This caused a memory leak. Free the hashes that are pointed to by
   the pointers when they are replaced.
 
 - Fix size initialization of ftrace direct function hash
 
   The ftrace direct function hash used by BPF initialized the hash size
   incorrectly. It checked the size of items to a hard coded 32, which made
   the hash bit size of 5. The hash size is supposed to be limited by the bit
   size of the hash, as the bitmask is allowed to be greater than 5. Rework
   the size check to first pass the number of elements to fls() and then
   compare that to FTRACE_HASH_MAX_BITS before allocating the hash.
 
 - Fix format output of ftrace_graph_ent_entry event
 
   The field depth of the ftrace_graph_ent_entry event is of size 4 but the
   output showed it as unsigned long and use "%lu". Change it to unsigned int
   and use "%u" in the print format that is displayed to user space.
 
 - Fix the trace event filter on strings
 
   Events can be filtered on numbers or string values. The return value
   checked from strncpy_from_kernel_nofault() and strncpy_from_user_nofault()
   was used to determine if reading the strings would fault or not. It would
   return fault if the value was non zero, which is basically meant that it
   was always considering the read as a fault.
 
 - Add selftest to test trace event string filtering
 
   In order to catch the breakage of the string filtering, add a self test to
   make sure that it continues to work.
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Merge tag 'trace-v6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Initialize hash variables in ftrace subops logic

   The fix that simplified the ftrace subops logic opened a path where
   some variables could be used without being initialized, and done
   subtly where the compiler did not catch it. Initialize those
   variables to the EMPTY_HASH, which is the default hash.

 - Reinitialize the hash pointers after they are freed

   Some of the hash pointers in the subop logic were freed but may still
   be referenced later. To prevent use-after-free bugs, initialize them
   back to the EMPTY_HASH.

 - Free the ftrace hashes when they are replaced

   The fix that simplified the subops logic updated some hash pointers,
   but left the original hash that they were pointing to where they are
   no longer used. This caused a memory leak. Free the hashes that are
   pointed to by the pointers when they are replaced.

 - Fix size initialization of ftrace direct function hash

   The ftrace direct function hash used by BPF initialized the hash size
   incorrectly. It checked the size of items to a hard coded 32, which
   made the hash bit size of 5. The hash size is supposed to be limited
   by the bit size of the hash, as the bitmask is allowed to be greater
   than 5. Rework the size check to first pass the number of elements to
   fls() and then compare that to FTRACE_HASH_MAX_BITS before allocating
   the hash.

 - Fix format output of ftrace_graph_ent_entry event

   The field depth of the ftrace_graph_ent_entry event is of size 4 but
   the output showed it as unsigned long and use "%lu". Change it to
   unsigned int and use "%u" in the print format that is displayed to
   user space.

 - Fix the trace event filter on strings

   Events can be filtered on numbers or string values. The return value
   checked from strncpy_from_kernel_nofault() and
   strncpy_from_user_nofault() was used to determine if reading the
   strings would fault or not. It would return fault if the value was
   non zero, which is basically meant that it was always considering the
   read as a fault.

 - Add selftest to test trace event string filtering

   In order to catch the breakage of the string filtering, add a self
   test to make sure that it continues to work.

* tag 'trace-v6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: selftests: Add testing a user string to filters
  tracing: Fix filter string testing
  ftrace: Fix type of ftrace_graph_ent_entry.depth
  ftrace: fix incorrect hash size in register_ftrace_direct()
  ftrace: Free ftrace hashes after they are replaced in the subops code
  ftrace: Reinitialize hash to EMPTY_HASH after freeing
  ftrace: Initialize variables for ftrace_startup/shutdown_subops()
2025-04-19 11:57:36 -07:00
Steven Rostedt
d481ee3524 tracing: selftests: Add testing a user string to filters
Running the following commands was broken:

  # 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

And would produce nothing when it should have produced something like:

      ls-1192    [007] .....  8169.828333: sys_openat(dfd: ffffffffffffff9c, filename: 7efc18359904, flags: 80000, mode: 0)

Add a test to check this case so that it will be caught if it breaks
again.

Link: https://lore.kernel.org/linux-trace-kernel/20250417183003.505835fb@gandalf.local.home/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/20250418101208.38dc81f5@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-04-18 11:26:01 -04:00
Steven Rostedt
07be53cfa8 selftests/ftrace: Differentiate bash and dash in dynevent_limitations.tc
bash and dash evaluate variables differently.
dash will evaluate '\\' every time it is read whereas bash does not.

  TEST_STRING="$TEST_STRING \\$i"
  echo $TEST_STRING

With i=123
On bash, that will print "\123"
but on dash, that will print the escape sequence of \123 as the \ will be
interpreted again in the echo.

The dynevent_limitations.tc test created a very large list of arguments to
test the maximum number of arguments to pass to the dynamic events file.
It had a loop of:

   TEST_STRING=$1
   # Acceptable
   for i in `seq 1 $MAX_ARGS`; do
     TEST_STRING="$TEST_STRING \\$i"
   done
   echo "$TEST_STRING" >> dynamic_events

This worked fine on bash, but when run on dash it failed.

This was due to dash interpreting the "\\$i" twice. Once when it was
assigned to TEST_STRING and a second time with the echo $TEST_STRING.

bash does not process the backslash more than the first time.

To solve this, assign a double backslash to a variable "bs" and then echo
it to "ts". If "ts" changes, it is dash, if not, it is bash. Then update
"bs" accordingly, and use that to assign TEST_STRING.

Now this could possibly just check if "$BASH" is defined or not, but this
is testing if the issue exists and not just which shell is being used.

Link: https://lore.kernel.org/r/20250414210900.4de5e8b9@gandalf.local.home
Fixes: 581a7b26ab ("selftests/ftrace: Add dynamic events argument limitation test case")
Reported-by: Mark Brown <broonie@kernel.org>
Closes: https://lore.kernel.org/all/350786cc-9e40-4396-ab95-4f10d69122fb@sirena.org.uk/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2025-04-16 12:47:41 -06:00
Steven Rostedt
a1fc89d409 tracing/selftest: Add test to better test subops filtering of function graph
A bug was discovered that showed the accounting of the subops of the
ftrace_ops filtering was incorrect. Add a new test to better test the
filtering.

This test creates two instances, where it will add various filters to both
the set_ftrace_filter and the set_ftrace_notrace files and enable
function_graph. Then it looks into the enabled_functions file to make sure
that the filters are behaving correctly.

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/20250409152720.380778379@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-04-11 16:02:08 -04:00
Linus Torvalds
a7e135fe59 Probes updates for v6.15:
- 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
2025-03-27 19:31:34 -07:00