- 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()
...
traceprobe_expand_meta_args() parses $argN with simple_strtoul() and
calls sprint_nth_btf_arg(n - 1, ...). For $arg0, n is 0 so the index is
-1. Because ctx->nr_params is signed, the "idx >= nr_params" guard in
sprint_nth_btf_arg() does not catch the negative index, and
ctx->params[-1].name_off is read out of bounds.
The normal per-argument path (parse_probe_vars()) already rejects
$arg0 via its argument-number check, but meta-argument expansion runs
before per-argument parsing and substitutes the value first, bypassing
that check.
Reject $arg0 explicitly during expansion.
Link: https://lore.kernel.org/all/20260724054435.146279-1-raushan.jhon@gmail.com/
Fixes: 18b1e870a4 ("tracing/probes: Add $arg* meta argument for all function args")
Cc: stable@vger.kernel.org
Signed-off-by: Raushan Patel <raushan.jhon@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
In store_trace_entry_data(), edata is cast to unsigned long for pointer
offset arithmetic before being cast back to unsigned long *. Cast edata
to u8 * instead.
Link: https://lore.kernel.org/all/178454425622.296567.16952341966130280432.stgit@devnote2/
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
In trace_probe_compare_arg_type(), prior to entering the comparison loop,
a->nr_args and b->nr_args are checked for equality. Since the loop
condition is i < a->nr_args, i is guaranteed to be less than b->nr_args
inside the loop.
Remove the redundant (b->nr_args <= i) check.
Link: https://lore.kernel.org/all/178454423769.296567.6694636865644203423.stgit@devnote2/
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
In __set_print_fmt(), LEN_OR_ZERO is defined as (len ? len - pos : 0).
If len is non-zero but smaller than pos, len - pos evaluates to a negative
integer. When passed as a size argument to snprintf(), this negative value
is cast to a large unsigned size_t, bypassing buffer size limits.
Ensure len > pos before subtracting to avoid integer underflow.
Link: https://lore.kernel.org/all/178454234934.290363.15247317871499514139.stgit@devnote2/
Fixes: 5bf652aaf4 ("tracing/probes: Integrate duplicate set_print_fmt()")
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
If trace_probe_log.argc is 0 in __trace_probe_log_err(), the loop
constructing the command string will not execute and p will remain equal to
command. Writing to *(p - 1) will cause an out-of-bounds access before
command. This should not happen, but better to be treated.
Reject if trace_probe_log.argc is 0.
Link: https://lore.kernel.org/all/178454233992.290363.18323091580600697731.stgit@devnote2/
Fixes: ab105a4fb8 ("tracing: Use tracing error_log with probe events")
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
In trace_probe_match_command_args(), a stack buffer buf[MAX_ARGSTR_LEN + 1]
(256 bytes) is used to format "<name>=<comm>". However, since name can
be up to 32 bytes (MAX_ARG_NAME_LEN) and comm up to 255 bytes
(MAX_ARGSTR_LEN), the formatted string can exceed 256 bytes and get
truncated by snprintf(), causing spurious argument matching failures.
Instead of formatting into a temporary buffer on stack, compare the
argument name, the '=' delimiter, and the comm expression directly.
Link: https://lore.kernel.org/all/178454233010.290363.10428767141343428804.stgit@devnote2/
Fixes: eb5bf81330 ("tracing/kprobe: Add per-probe delete from event")
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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>
Decompose parse_probe_vars() by extracting retval, stack, current task
struct, and function argument parsing logic into dedicated static
helper functions (parse_probe_var_retval, parse_probe_var_stack,
parse_probe_var_current, and parse_probe_var_arg). This simplifies
parse_probe_vars() and improves its readability.
Link: https://lore.kernel.org/all/178399137612.27810.14869178899276413372.stgit@devnote2/
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
When tracing the kernel local variables, sometimes we need to get the
CPU local variables. To access it, current simple dereference is not
enough.
Thus, introduce a special this_cpu_read() dereference to access per-cpu
variable for the current CPU (accessing other CPU variable may race with
updates on other CPUs). Also this_cpu_ptr() is for accessing per-cpu
pointer.
Those are working as same as the kernel percpu macro.
Link: https://lore.kernel.org/all/178271367680.1176915.4711734074448973989.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Since we can use the BTF to cast value to a structure pointer type,
it is useful to introduce "$current" special variable support to
fetcharg.
User can define a fetcharg to access current task_struct properties
using BTF info. e.g.
$current->cpus_ptr
Link: https://lore.kernel.org/all/178271366709.1176915.15320906169981578568.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Add a field specifier option for the typecast. This works like
container_of() macro.
(STRUCT[,FIELD[.FIELD2...]])VAR
This is equivalent to :
container_of(VAR, struct STRUCT, FIELD[.FIELD2...])
For example:
echo "f tick_nohz_handler next_tick=(tick_sched,sched_timer)timer->next_tick" >> dynamic_events
This will trace tick_nohz_handler() with its tick_sched::next_tick which
is converted from @timer by contianer_of(tick, struct tick_sched, sched_timer).
So, if you enabkle both fprobes:tick_nohz_handler__entry and
timer:hrtimer_expire_entry events, we will see something like:
<idle>-0 [002] d.h1. 3778.087272: hrtimer_expire_entry: hrtimer=00000000d63db328 f
unction=tick_nohz_handler now=3777450051040
<idle>-0 [002] d.h1. 3778.087281: tick_nohz_handler__entry: (tick_nohz_handler+0x4
/0x140) next_tick=3777450000000
Link: https://lore.kernel.org/all/178271365745.1176915.725923927180862257.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
This allows type casting to various fetchargs without parentheses
by recursively calling parse_probe_arg on the target when type
casting is used.
For example, this allows the following expressions:
- (STRUCT)%REG->FIELD
- (STRUCT)$stackN->FIELD
- (STRUCT)@SYM->FIELD
Note that @SYM+/-OFFSET with typecast needs parentheses like:
- (STRUCT)(@SYM-8)->FIELD
Link: https://lore.kernel.org/all/178271364804.1176915.17600229399446264813.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
When we hit an open parenthesis right after typecast closing
parenthesis, it means we have nested typecast. This allows us to
typecast a generic data member in a structure to a pointer to
another structure.
For example, to cast a DATA_MEMBER of VAR structure to STRUCT pointer
and get MEMBER value.
(STRUCT)(VAR->DATA_MEMBER)->MEMBER
Also, we can nest typecast.
(STRUCT1)((STRUCT2)$ARG->FIELD2)->FIELD1
Currently the max nest level is limited to 3.
This also allows user to use typecasting for registers or stacks on
kprobe events. e.g.
(STRUCT)(%ax)->MEMBER
(STRUCT)($stack0)->MEMBER
Link: https://lore.kernel.org/all/178271363855.1176915.16793301788257446529.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Support BTF typecast feature on other probe events, but only if it is
kernel function entry or return, and must use function parameter name
or $retval. This means you can do:
(STRUCT)PARAM->MEMBER
Note: you can not use other variables like $stackN, %reg etc. That
needs nesting support.
To support other probe events, we just need to use last_struct type
when we find a function parameter in parse_btf_arg().
This also updates <tracefs>/README file to show struct typecast.
Link: https://lore.kernel.org/all/178271362928.1176915.12235759508786922490.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
For debugging probe events, it is helpful to verify the compiled
fetch instructions for each probe argument. This introduces a new
kernel config CONFIG_PROBE_EVENTS_DUMP_FETCHARG to decode the
instruction sequence of each argument and display it under a
commented line starting with '#' immediately following the dynamic
event definition (such as in dynamic_events, kprobe_events,
uprobe_events, etc.).
For example:
/sys/kernel/tracing # cat dynamic_events
p:kprobes/p_vfs_read_0 vfs_read arg1=+0(file):ustring arg2=%ax:x16
# arg1: ARG(0) -> ST_USTRING(offset=0,size=4) -> END
# arg2: REG(80) -> ST_RAW(size=2) -> END
Link: https://lore.kernel.org/all/178271359508.1176915.11895926894608440183.stgit@devnote2/
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
We can pass NULL as id pointer to btf_type_skip_modifiers if we do not
need the id of the returned btf_type.
Link: https://lore.kernel.org/all/20260623132937.3494895-1-martin@kaiser.cx/
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
The shared probe argument parser rejects file offsets for kernel probes.
This path is used outside the kprobe event parser too, but the diagnostic
currently says "with kprobe" even when emitted from another probe path.
Make the diagnostic probe-agnostic.
Link: https://lore.kernel.org/all/20260622160032.99834-1-pyudistira519@gmail.com/
Signed-off-by: Yudistira Putra <pyudistira519@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Since $comm or $COMM are not event field but special fetcharg
variables to access current->comm, It should not be accessed
without '$' prefix even with typecast.
Link: https://lore.kernel.org/all/178231209724.732967.12049805699091810641.stgit@devnote2/
Fixes: 69efd863a7 ("tracing/eprobes: Allow use of BTF names to dereference pointers")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Since commit 533059281e ("tracing: probeevent: Introduce new argument
fetching code") wrongly use @offset local variable during the parsing,
the offset value is added twice when dereferencing.
Reset the @offset after setting it in FETCH_OP_FOFFS.
Link: https://lore.kernel.org/all/178217905962.643090.1978577464942171332.stgit@devnote2/
Fixes: 533059281e ("tracing: probeevent: Introduce new argument fetching code")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Add syntax to the parsing of eprobes to be able to typecast a trace event
field that is a pointer to a structure.
Currently, a dereference must be a number, where the user has to figure
out manually the offset of a member of a structure that they want to
dereference.
But for event probes that records a field that happens to be a pointer to
a structure, it cannot dereference these values with BTF naming, but
must use numerical offsets.
For example, to find out what device a sk_buff is pointing to in the
net_dev_xmit trace event, one must first use gdb to find the offsets of the
members of the structures:
(gdb) p &((struct sk_buff *)0)->dev
$1 = (struct net_device **) 0x10
(gdb) p &((struct net_device *)0)->name
$2 = (char (*)[16]) 0x118
And then use the raw numbers to dereference:
# echo 'e:xmit net.net_dev_xmit +0x118(+0x10($skbaddr)):string' >> dynamic_events
If BTF is in the kernel, then instead, the skbaddr can be typecast to
sk_buff and use the normal dereference logic.
# echo 'e:xmit net.net_dev_xmit (sk_buff)skbaddr->dev->name:string' >> dynamic_events
# echo 1 > events/eprobes/xmit/enable
# cat trace
[..]
sshd-session-1022 [000] b..2. 860.249343: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.250061: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.250142: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.263553: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.283820: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.302716: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.322905: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.342828: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.362268: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.382335: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.400856: xmit: (net.net_dev_xmit) arg1="enp7s0"
sshd-session-1022 [000] b..2. 860.419893: xmit: (net.net_dev_xmit) arg1="enp7s0"
The syntax is simply: (STRUCT)(FIELD)->MEMBER[->MEMBER..]
Also add comments around the #else and #endif of #ifdef CONFIG_PROBE_EVENTS_BTF_ARGS
to know what they are for.
Link: https://lore.kernel.org/all/20260601130746.2139d926@gandalf.local.home/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Store probe entry fetch instructions in the probe_entry_arg
allocation instead of allocating a separate instruction array.
This keeps the entry fetch code tied to the entry argument lifetime while
leaving regular probe_arg instruction arrays separately allocated and
freed.
Assisted-by: Codex:GPT-5.5
Link: https://lore.kernel.org/all/20260520215817.16560-1-rosenp@gmail.com/
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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>
There currently isn't a max limit an event probe can be. One could make an
event greater than PAGE_SIZE, which makes the event useless because if
it's bigger than the max event that can be recorded into the ring buffer,
then it will never be recorded.
A event probe should never need to be greater than 3K, so make that the
max size. As long as the max is less than the max that can be recorded
onto the ring buffer, it should be fine.
Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Fixes: 93ccae7a22 ("tracing/kprobes: Support basic types on dynamic events")
Link: https://patch.msgid.link/20260428122302.706610ba@gandalf.local.home
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
parse_probe_arg() accepts quoted immediate strings and passes the body
after the opening quote to __parse_imm_string(). That helper currently
computes strlen(str) and immediately dereferences str[len - 1], which
underflows when the body is empty and not closed with double-quotation.
Reject empty non-closed immediate strings before checking for the closing quote.
Link: https://lore.kernel.org/all/20260401160315.88518-1-pengpeng@iscas.ac.cn/
Fixes: a42e3c4de9 ("tracing/probe: Add immediate string parameter support")
Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
This converts some of the visually simpler cases that have been split
over multiple lines. I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.
Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script. I probably had made it a bit _too_ trivial.
So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.
The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
- Fix accounting of stop_count in file release
On opening the trace file, if "pause-on-trace" option is set, it will
increment the stop_count. On file release, it checks if stop_count is set,
and if so it decrements it. Since this code was originally written, the
stop_count can be incremented by other use cases. This makes just checking
the stop_count not enough to know if it should be decremented.
Add a new iterator flag called "PAUSE" and have it set if the open
disables tracing and only decrement the stop_count if that flag is set on
close.
- Remove length field in trace_seq_printf() of print_synth_event()
When printing the synthetic event that has a static length array field,
the vsprintf() of the trace_seq_printf() triggered a "(efault)" in the
output. That's because the print_fmt replaced the "%.*s" with "%s" causing
the arguments to be off.
- Fix a bunch of typos
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Merge tag 'trace-v6.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix accounting of stop_count in file release
On opening the trace file, if "pause-on-trace" option is set, it will
increment the stop_count. On file release, it checks if stop_count is
set, and if so it decrements it. Since this code was originally
written, the stop_count can be incremented by other use cases. This
makes just checking the stop_count not enough to know if it should be
decremented.
Add a new iterator flag called "PAUSE" and have it set if the open
disables tracing and only decrement the stop_count if that flag is
set on close.
- Remove length field in trace_seq_printf() of print_synth_event()
When printing the synthetic event that has a static length array
field, the vsprintf() of the trace_seq_printf() triggered a
"(efault)" in the output. That's because the print_fmt replaced the
"%.*s" with "%s" causing the arguments to be off.
- Fix a bunch of typos
* tag 'trace-v6.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing: Fix typo in trace_seq.c
tracing: Fix typo in trace_probe.c
tracing: Fix multiple typos in trace_osnoise.c
tracing: Fix multiple typos in trace_events_user.c
tracing: Fix typo in trace_events_trigger.c
tracing: Fix typo in trace_events_hist.c
tracing: Fix typo in trace_events_filter.c
tracing: Fix multiple typos in trace_events.c
tracing: Fix multiple typos in trace.c
tracing: Fix typo in ring_buffer_benchmark.c
tracing: Fix multiple typos in ring_buffer.c
tracing: Fix typo in fprobe.c
tracing: Fix typo in fpgraph.c
tracing: Fix fixed array of synthetic event
tracing: Fix enabling of tracing on file release
- 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
Since traceprobe_parse_event_name() is a bit complicated, add a
kerneldoc for explaining the behavior.
Link: https://lore.kernel.org/all/175323430565.57270.2602609519355112748.stgit@devnote2/
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Sort the #include directives in trace_probe* files alphabetically for
easier maintenance and avoid double includes.
This also groups headers as linux-generic, asm-generic, and local
headers.
Link: https://lore.kernel.org/all/175323424678.57270.11975372127870059007.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
After a recent change in clang to strengthen uninitialized warnings [1],
it points out that in one of the error paths in parse_btf_arg(), params
is used uninitialized:
kernel/trace/trace_probe.c:660:19: warning: variable 'params' is uninitialized when used here [-Wuninitialized]
660 | return PTR_ERR(params);
| ^~~~~~
Match many other NO_BTF_ENTRY error cases and return -ENOENT, clearing
up the warning.
Link: https://lore.kernel.org/all/20250715-trace_probe-fix-const-uninit-warning-v1-1-98960f91dd04@kernel.org/
Cc: stable@vger.kernel.org
Closes: https://github.com/ClangBuiltLinux/linux/issues/2110
Fixes: d157d76944 ("tracing/probes: Support BTF field access from $retval")
Link: 2464313eef [1]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cleanup __store_entry_arg() so that it is easier to understand.
The main complexity may come from combining the loops for finding
stored-entry-arg and max-offset and appending new entry.
This split those different loops into 3 parts, lookup the same
entry-arg, find the max offset and append new entry.
Link: https://lore.kernel.org/all/174323039929.348535.4705349977127704120.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Since the shared trace_probe_log variable can be accessed and
modified via probe event create operation of kprobe_events,
uprobe_events, and dynamic_events, it should be protected.
In the dynamic_events, all operations are serialized by
`dyn_event_ops_mutex`. But kprobe_events and uprobe_events
interfaces are not serialized.
To solve this issue, introduces dyn_event_create(), which runs
create() operation under the mutex, for kprobe_events and
uprobe_events. This also uses lockdep to check the mutex is
held when using trace_probe_log* APIs.
Link: https://lore.kernel.org/all/174684868120.551552.3068655787654268804.stgit@devnote2/
Reported-by: Paul Cacheux <paulcacheux@gmail.com>
Closes: https://lore.kernel.org/all/20250510074456.805a16872b591e2971a4d221@kernel.org/
Fixes: ab105a4fb8 ("tracing: Use tracing error_log with probe events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
strlen() returns a string length excluding the null byte. If the string
length equals to the maximum buffer length, the buffer will have no
space for the NULL terminating character.
This commit checks this condition and returns failure for it.
Link: https://lore.kernel.org/all/20241007144724.920954-1-leo.yan@arm.com/
Fixes: dec65d79fd ("tracing/probe: Check event name length correctly")
Signed-off-by: Leo Yan <leo.yan@arm.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
btf_find_struct_member() might return NULL or an error via the
ERR_PTR() macro. However, its caller in parse_btf_field() only checks
for the NULL condition. Fix this by using IS_ERR() and returning the
error up the stack.
Link: https://lore.kernel.org/all/20240527094351.15687-1-clopez@suse.de/
Fixes: c440adfbe3 ("tracing/probes: Support BTF based data structure field access")
Signed-off-by: Carlos López <clopez@suse.de>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
- tracing/probes: Adding new pseudo-types %pd and %pD support for dumping
dentry name from 'struct dentry *' and file name from 'struct file *'.
- uprobes: Some performance optimizations have been done.
. Speed up the BPF uprobe event by delaying the fetching of the uprobe
event arguments that are not used in BPF.
. Avoid locking by speculatively checking whether uprobe event is valid.
. Reduce lock contention by using read/write_lock instead of spinlock for
uprobe list operation. This improved BPF uprobe benchmark result 43% on
average.
- rethook: Removes non-fatal warning messages when tracing stack from BPF
and skip rcu_is_watching() validation in rethook if possible.
- objpool: Optimizing objpool (which is used by kretprobes and fprobe as
rethook backend storage) by inlining functions and avoid caching nr_cpu_ids
because it is a const value.
- fprobe: Add entry/exit callbacks types (code cleanup)
- kprobes: Check ftrace was killed in kprobes if it uses ftrace.
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Merge tag 'probes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes updates from Masami Hiramatsu:
- tracing/probes: Add new pseudo-types %pd and %pD support for dumping
dentry name from 'struct dentry *' and file name from 'struct file *'
- uprobes performance optimizations:
- Speed up the BPF uprobe event by delaying the fetching of the
uprobe event arguments that are not used in BPF
- Avoid locking by speculatively checking whether uprobe event is
valid
- Reduce lock contention by using read/write_lock instead of
spinlock for uprobe list operation. This improved BPF uprobe
benchmark result 43% on average
- rethook: Remove non-fatal warning messages when tracing stack from
BPF and skip rcu_is_watching() validation in rethook if possible
- objpool: Optimize objpool (which is used by kretprobes and fprobe as
rethook backend storage) by inlining functions and avoid caching
nr_cpu_ids because it is a const value
- fprobe: Add entry/exit callbacks types (code cleanup)
- kprobes: Check ftrace was killed in kprobes if it uses ftrace
* tag 'probes-v6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
kprobe/ftrace: bail out if ftrace was killed
selftests/ftrace: Fix required features for VFS type test case
objpool: cache nr_possible_cpus() and avoid caching nr_cpu_ids
objpool: enable inlining objpool_push() and objpool_pop() operations
rethook: honor CONFIG_FTRACE_VALIDATE_RCU_IS_WATCHING in rethook_try_get()
ftrace: make extra rcu_is_watching() validation check optional
uprobes: reduce contention on uprobes_tree access
rethook: Remove warning messages printed for finding return address of a frame.
fprobe: Add entry/exit callbacks types
selftests/ftrace: add fprobe test cases for VFS type "%pd" and "%pD"
selftests/ftrace: add kprobe test cases for VFS type "%pd" and "%pD"
Documentation: tracing: add new type '%pd' and '%pD' for kprobe
tracing/probes: support '%pD' type for print struct file's name
tracing/probes: support '%pd' type for print struct dentry's name
uprobes: add speculative lockless system-wide uprobe filter check
uprobes: prepare uprobe args buffer lazily
uprobes: encapsulate preparation of uprobe args buffer
Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c
35d92abfba ("net: hns3: fix kernel crash when devlink reload during initialization")
2a1a1a7b5f ("net: hns3: add command queue trace for hns3")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
