linux-stable.git/tools/perf/util/tool.c, branch linux-rolling-stable

perf tool: Fix missing schedstat delegates and dont_split_sample_group in delegate_tool

2026-07-24T14:19:59+00:00

[ Upstream commit 09d355618f7ccc27ffc7fc668b2e232872962079 ]

delegate_tool was missing the delegate overrides for schedstat_cpu
and schedstat_domain. As a result, when allocated with zalloc, these
callbacks defaulted to NULL, causing a segmentation fault crash if
any schedstat events were delivered during event processing.
Fix this by adding delegate_schedstat_cpu and delegate_schedstat_domain
via the CREATE_DELEGATE_OP2 macro, and ensuring delegate_tool__init
correctly registers them.

Additionally, delegate_tool__init completely omitted copying the
dont_split_sample_group property from the delegate. This would cause
wrapper tools to default the flag to false, which corrupts piped event
processing (e.g., in perf inject) by triggering duplicate event
deliveries on split sample values in deliver_sample_group().

Similarly, perf_tool__init() omitted the initialization of this
boolean field. On stack-allocated tools that rely on this initializer
(like intel-tpebs or __cmd_evlist), this could result in uninitialized
stack garbage evaluating to true—silently dropping non-leader event
members in deliver_sample_group().

Fix both issues by properly copying the field in delegate_tool__init
and initializing it to false in perf_tool__init.

Fixes: 6331b266935916bf ("perf tool: Add a delegate_tool that just delegates actions to another tool")
Fixes: 79bcd34e0f3da39f ("perf inject: Fix leader sampling inserting additional samples")
Assisted-by: Gemini-CLI:Google Gemini 3
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Gabriel Marin 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf sched stats: Add record and rawdump support

2026-01-22T15:29:28+00:00

Define new, perf tool only, sample types and their layouts. Add logic
to parse /proc/schedstat, convert it to perf sample format and save
samples to perf.data file with `perf sched stats record` command.

Also add logic to read perf.data file, interpret schedstat samples and
print rawdump of samples with `perf script -D`.

Note that, /proc/schedstat file output is standardized with version
number. The patch supports v15 but older or newer version can be added
easily.

Co-developed-by: Ravi Bangoria 
Signed-off-by: Ravi Bangoria 
Signed-off-by: Swapnil Sapkal 
Tested-by: Chen Yu 
Tested-by: James Clark 
Acked-by: Ian Rogers 
Acked-by: Peter Zijlstra 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Anubhav Shelat 
Cc: Ben Gainey 
Cc: Blake Jones 
Cc: Chun-Tse Shao 
Cc: David Vernet 
Cc: Dmitriy Vyukov 
Cc: Dr. David Alan Gilbert 
Cc: Gautham Shenoy 
Cc: Graham Woodward 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Juri Lelli 
Cc: K Prateek Nayak 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Madadi Vineeth Reddy 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Sandipan Das 
Cc: Santosh Shukla 
Cc: Shrikanth Hegde 
Cc: Steven Rostedt (VMware) 
Cc: Tejun Heo 
Cc: Thomas Falcon 
Cc: Tim Chen 
Cc: Vincent Guittot 
Cc: Yang Jihong 
Cc: Yujie Liu 
Cc: Zhongqiu Han 
[ PRIu64 needs uint64_t, not 'unsigned long' to work on both 32-bit and 64-bit ]
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Merge deferred user callchains

2025-12-03T05:59:14+00:00

Save samples with deferred callchains in a separate list and deliver
them after merging the user callchains.  If users don't want to merge
they can set tool->merge_deferred_callchains to false to prevent the
behavior.

With previous result, now perf script will show the merged callchains.

  $ perf script
  ...
  pwd    2312   121.163435:     249113 cpu/cycles/P:
          ffffffff845b78d8 __build_id_parse.isra.0+0x218 ([kernel.kallsyms])
          ffffffff83bb5bf6 perf_event_mmap+0x2e6 ([kernel.kallsyms])
          ffffffff83c31959 mprotect_fixup+0x1e9 ([kernel.kallsyms])
          ffffffff83c31dc5 do_mprotect_pkey+0x2b5 ([kernel.kallsyms])
          ffffffff83c3206f __x64_sys_mprotect+0x1f ([kernel.kallsyms])
          ffffffff845e6692 do_syscall_64+0x62 ([kernel.kallsyms])
          ffffffff8360012f entry_SYSCALL_64_after_hwframe+0x76 ([kernel.kallsyms])
              7f18fe337fa7 mprotect+0x7 (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2)
              7f18fe330e0f _dl_sysdep_start+0x7f (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2)
              7f18fe331448 _dl_start_user+0x0 (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2)
  ...

The old output can be get using --no-merge-callchain option.
Also perf report can get the user callchain entry at the end.

  $ perf report --no-children --stdio -q -S __build_id_parse.isra.0
  # symbol: __build_id_parse.isra.0
       8.40%  pwd      [kernel.kallsyms]
              |
              ---__build_id_parse.isra.0
                 perf_event_mmap
                 mprotect_fixup
                 do_mprotect_pkey
                 __x64_sys_mprotect
                 do_syscall_64
                 entry_SYSCALL_64_after_hwframe
                 mprotect
                 _dl_sysdep_start
                 _dl_start_user

Reviewed-by: Ian Rogers 
Signed-off-by: Namhyung Kim

perf tools: Minimal DEFERRED_CALLCHAIN support

2025-12-03T00:13:32+00:00

Add a new event type for deferred callchains and a new callback for the
struct perf_tool.  For now it doesn't actually handle the deferred
callchains but it just marks the sample if it has the PERF_CONTEXT_
USER_DEFFERED in the callchain array.

At least, perf report can dump the raw data with this change.  Actually
this requires the next commit to enable attr.defer_callchain, but if you
already have a data file, it'll show the following result.

  $ perf report -D
  ...
  0x2158@perf.data [0x40]: event: 22
  .
  . ... raw event: size 64 bytes
  .  0000:  16 00 00 00 02 00 40 00 06 00 00 00 0b 00 00 00  ......@.........
  .  0010:  03 00 00 00 00 00 00 00 a7 7f 33 fe 18 7f 00 00  ..........3.....
  .  0020:  0f 0e 33 fe 18 7f 00 00 48 14 33 fe 18 7f 00 00  ..3.....H.3.....
  .  0030:  08 09 00 00 08 09 00 00 e6 7a e7 35 1c 00 00 00  .........z.5....

  121163447014 0x2158 [0x40]: PERF_RECORD_CALLCHAIN_DEFERRED(IP, 0x2): 2312/2312: 0xb00000006
  ... FP chain: nr:3
  .....  0: 00007f18fe337fa7
  .....  1: 00007f18fe330e0f
  .....  2: 00007f18fe331448
  : unhandled!

Reviewed-by: Ian Rogers 
Signed-off-by: Namhyung Kim

perf tool: Add a delegate_tool that just delegates actions to another tool

2025-11-07T21:25:05+00:00

Add an ability to be able to compose perf_tools, by having one perform
an action and then calling a delegate. Currently the perf_tools have
if-then-elses setting the callback and then if-then-elses within the
callback. Understanding the behavior is complex as it is in two places
and logic for numerous operations, within things like perf inject, is
interwoven. By chaining perf_tools together based on command line
options this kind of code can be avoided.

Signed-off-by: Ian Rogers 
Signed-off-by: Namhyung Kim

perf tool: Add the perf_tool argument to all callbacks

2025-11-07T21:25:05+00:00

Getting context for what a tool is doing, such as the perf_inject
instance, using container_of the tool is a common pattern in the
code. This isn't possible event_op2, event_op3 and event_op4 callbacks
as the tool isn't passed. Add the argument and then fix function
signatures to match. As tools maybe reading a tool from somewhere
else, change that code to use the passed in tool.

Signed-off-by: Ian Rogers 
Signed-off-by: Namhyung Kim

perf session: Add accessor for session->header.env

2025-07-25T17:37:56+00:00

The perf_env from the header in the session is frequently accessed,
add an accessor function rather than access directly. Cache the value
to avoid repeated calls. No behavioral change.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250724163302.596743-10-irogers@google.com
Signed-off-by: Namhyung Kim

perf tools: display the new PERF_RECORD_BPF_METADATA event

2025-06-20T21:48:56+00:00

Here's some example "perf script -D" output for the new event type. The
": unhandled!" message is from tool.c, analogous to other behavior there.
I've elided some rows with all NUL characters for brevity, and I wrapped
one of the >75-column lines to fit in the commit guidelines.

0x50fc8@perf.data [0x260]: event: 84
.
. ... raw event: size 608 bytes
.  0000:  54 00 00 00 00 00 60 02 62 70 66 5f 70 72 6f 67  T.....`.bpf_prog
.  0010:  5f 31 65 30 61 32 65 33 36 36 65 35 36 66 31 61  _1e0a2e366e56f1a
.  0020:  32 5f 70 65 72 66 5f 73 61 6d 70 6c 65 5f 66 69  2_perf_sample_fi
.  0030:  6c 74 65 72 00 00 00 00 00 00 00 00 00 00 00 00  lter............
.  0040:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[...]
.  0110:  74 65 73 74 5f 76 61 6c 75 65 00 00 00 00 00 00  test_value......
.  0120:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[...]
.  0150:  34 32 00 00 00 00 00 00 00 00 00 00 00 00 00 00  42..............
.  0160:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
[...]

0 0x50fc8 [0x260]: PERF_RECORD_BPF_METADATA \
      prog bpf_prog_1e0a2e366e56f1a2_perf_sample_filter
  entry 0:           test_value = 42
: unhandled!

Signed-off-by: Blake Jones 
Link: https://lore.kernel.org/r/20250612194939.162730-5-blakejones@google.com
Signed-off-by: Namhyung Kim

perf record: Add 8-byte aligned event type PERF_RECORD_COMPRESSED2

2025-05-16T20:31:40+00:00

The original PERF_RECORD_COMPRESS is not 8-byte aligned, which can cause
asan runtime error:

  # Build with asan
  $ make -C tools/perf O=/tmp/perf DEBUG=1 EXTRA_CFLAGS="-O0 -g -fno-omit-frame-pointer -fsanitize=undefined"
  # Test success with many asan runtime errors:
  $ /tmp/perf/perf test "Zstd perf.data compression/decompression" -vv
   83: Zstd perf.data compression/decompression:
  ...
  util/session.c:1959:13: runtime error: member access within misaligned address 0x7f69e3f99653 for type 'union perf_event', which requires 13 byte alignment
  0x7f69e3f99653: note: pointer points here
   d0  3a 50 69 44 00 00 00 00  00 08 00 bb 07 00 00 00  00 00 00 44 00 00 00 00  00 00 00 ff 07 00 00
                ^
  util/session.c:2163:22: runtime error: member access within misaligned address 0x7f69e3f99653 for type 'union perf_event', which requires 8 byte alignment
  0x7f69e3f99653: note: pointer points here
   d0  3a 50 69 44 00 00 00 00  00 08 00 bb 07 00 00 00  00 00 00 44 00 00 00 00  00 00 00 ff 07 00 00
                ^
  ...

Since there is no way to align compressed data in zstd compression, this
patch add a new event type `PERF_RECORD_COMPRESSED2`, which adds a field
`data_size` to specify the actual compressed data size.

The `header.size` contains the total record size, including the padding
at the end to make it 8-byte aligned.

Tested with `Zstd perf.data compression/decompression`

Signed-off-by: Chun-Tse Shao 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ben Gainey 
Cc: Christophe Leroy 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Nick Terrell 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20250303183646.327510-1-ctshao@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tool: Remove perf_tool__fill_defaults()

2024-08-12T21:13:58+00:00

Now all tools are fully initialized prior to use it has no use so
remove.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Anshuman Khandual 
Cc: Athira Rajeev 
Cc: Huacai Chen 
Cc: Ilkka Koskinen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Jonathan Cameron 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Nick Desaulniers 
Cc: Nick Terrell 
Cc: Oliver Upton 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Sun Haiyong 
Cc: Suzuki Poulouse 
Cc: Will Deacon 
Cc: Yanteng Si 
Cc: Yicong Yang 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20240812204720.631678-27-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo