linux-toradex.git/tools/perf/builtin-buildid-cache.c, branch v7.0-rc2

perf symbol: Fix ENOENT case for filename__read_build_id

2025-12-17T15:30:51+00:00

Some callers of filename__read_build_id assume the error value must be
-1, fix by making them handle all < 0 values.

If is_regular_file fails in filename__read_build_id then it could be
the file is missing (ENOENT) and it would be wrong to return
-EWOULDBLOCK in that case. Fix the logic so -EWOULDBLOCK is only
reported if other errors with stat haven't occurred.

Fixes: 834ebb5678d7 ("perf tools: Don't read build-ids from non-regular files")
Signed-off-by: Ian Rogers 
Reviewed-by: James Clark 
Signed-off-by: Namhyung Kim

perf tools: Don't read build-ids from non-regular files

2025-11-26T18:13:38+00:00

Simplify the build ID reading code by removing the non-blocking option.
Having to pass the correct option to this function was fragile and a
mistake would result in a hang, see the linked fix. Furthermore,
compressed files are always opened blocking anyway, ignoring the
non-blocking option.

We also don't expect to read build IDs from non-regular files. The only
hits to this function that are non-regular are devices that won't be elf
files with build IDs, for example "/dev/dri/renderD129".

Now instead of opening these as non-blocking and failing to read, we
skip them. Even if something like a pipe or character device did have a
build ID, I don't think it would have worked because you need to call
read() in a loop, check for -EAGAIN and handle timeouts to make
non-blocking reads work.

Link: https://lore.kernel.org/linux-perf-users/20251022-james-perf-fix-dso-block-v1-1-c4faab150546@linaro.org/
Signed-off-by: James Clark 
Signed-off-by: Namhyung Kim

perf symbol: Add blocking argument to filename__read_build_id

2025-08-25T22:07:18+00:00

When synthesizing build-ids, for build ID mmap2 events, they will be
added for data mmaps if -d/--data is specified. The files opened for
their build IDs may block on the open causing perf to hang during
synthesis. There is some robustness in existing calls to
filename__read_build_id by checking the file path is to a regular
file, which unfortunately fails for symlinks. Rather than adding more
is_regular_file calls, switch filename__read_build_id to take a
"block" argument and specify O_NONBLOCK when this is false. The
existing is_regular_file checking callers and the event synthesis
callers are made to pass false and thereby avoiding the hang.

Fixes: 53b00ff358dc ("perf record: Make --buildid-mmap the default")
Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250823000024.724394-3-irogers@google.com
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 build-id: Ensure struct build_id is empty before use

2025-07-25T17:37:55+00:00

If a build ID is read then not all code paths may ensure it is empty
before use. Initialize the build_id to be zero-ed unless there is
clear initialization such as a call to build_id__init.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250724163302.596743-6-irogers@google.com
Signed-off-by: Namhyung Kim

perf build-id: Change sprintf functions to snprintf

2025-07-25T17:37:13+00:00

Pass in a size argument rather than implying all build id strings must
be SBUILD_ID_SIZE.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250724163302.596743-4-irogers@google.com
[ fixed some build errors ]
Signed-off-by: Namhyung Kim

perf dso: Add reference count checking and accessor functions

2024-05-06T18:28:49+00:00

Add reference count checking to struct dso, this can help with
implementing correct reference counting discipline. To avoid
RC_CHK_ACCESS everywhere, add accessor functions for the variables in
struct dso.

The majority of the change is mechanical in nature and not easy to
split up.

Committer testing:

'perf test' up to this patch shows no regressions.

But:

  util/symbol.c: In function ‘dso__load_bfd_symbols’:
  util/symbol.c:1683:9: error: too few arguments to function ‘dso__set_adjust_symbols’
   1683 |         dso__set_adjust_symbols(dso);
        |         ^~~~~~~~~~~~~~~~~~~~~~~
  In file included from util/symbol.c:21:
  util/dso.h:268:20: note: declared here
    268 | static inline void dso__set_adjust_symbols(struct dso *dso, bool val)
        |                    ^~~~~~~~~~~~~~~~~~~~~~~
  make[6]: *** [/home/acme/git/perf-tools-next/tools/build/Makefile.build:106: /tmp/tmp.ZWHbQftdN6/util/symbol.o] Error 1
    MKDIR   /tmp/tmp.ZWHbQftdN6/tests/workloads/
  make[6]: *** Waiting for unfinished jobs....

This was updated:

  -       symbols__fixup_end(&dso->symbols, false);
  -       symbols__fixup_duplicate(&dso->symbols);
  -       dso->adjust_symbols = 1;
  +       symbols__fixup_end(dso__symbols(dso), false);
  +       symbols__fixup_duplicate(dso__symbols(dso));
  +       dso__set_adjust_symbols(dso);

But not build tested with BUILD_NONDISTRO and libbfd devel files installed
(binutils-devel on fedora).

Add the missing argument:

   	symbols__fixup_end(dso__symbols(dso), false);
   	symbols__fixup_duplicate(dso__symbols(dso));
  -	dso__set_adjust_symbols(dso);
  +	dso__set_adjust_symbols(dso, true);

Signed-off-by: Ian Rogers 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Ahelenia Ziemiańska 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Athira Rajeev 
Cc: Ben Gainey 
Cc: Changbin Du 
Cc: Chengen Du 
Cc: Colin Ian King 
Cc: Dima Kogan 
Cc: Ilkka Koskinen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: K Prateek Nayak 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Li Dong 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Paran Lee 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Sun Haiyong 
Cc: Thomas Richter 
Cc: Tiezhu Yang 
Cc: Yanteng Si 
Cc: zhaimingbing 
Link: https://lore.kernel.org/r/20240504213803.218974-6-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-cache: Fix use of uninitialized value

2023-10-12T17:01:56+00:00

The buildid filename is first determined and then from this the
buildid read. If getting the filename fails then the buildid will be
used for a later memcmp uninitialized. Detected by clang-tidy.

Signed-off-by: Ian Rogers 
Acked-by: Namhyung Kim 
Cc: Ravi Bangoria 
Cc: Nick Desaulniers 
Cc: Yang Jihong 
Cc: Huacai Chen 
Cc: Nathan Chancellor 
Cc: Kan Liang 
Cc: llvm@lists.linux.dev
Cc: Ming Wang 
Cc: Tom Rix 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20231009183920.200859-7-irogers@google.com
Signed-off-by: Namhyung Kim

perf record: Disable debuginfod by default

2022-01-15T20:41:25+00:00

Fedora 35 sets DEBUGINFOD_URLS by default, which might lead to
unexpected stalls in perf record exit path, when we try to cache
profiled binaries.

  # DEBUGINFOD_PROGRESS=1 ./perf record -a
  ^C[ perf record: Woken up 1 times to write data ]
  Downloading from https://debuginfod.fedoraproject.org/ 447069
  Downloading from https://debuginfod.fedoraproject.org/ 1502175
  Downloading \^Z

Disabling DEBUGINFOD_URLS by default in perf record and adding
debuginfod option and .perfconfig variable support to enable id.

  Default without debuginfo processing:
  # perf record -a

  Using system debuginfod setup:
  # perf record -a --debuginfod

  Using custom debuginfd url:
  # perf record -a --debuginfod='https://evenbetterdebuginfodserver.krava'

Adding single perf_debuginfod_setup function and using
it also in perf buildid-cache command.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Frank Ch. Eigler 
Cc: Ian Rogers 
Cc: Mark Rutland 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20211209200425.303561-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Remove repipe argument from perf_session__new()

2021-08-02T13:06:51+00:00

The repipe argument is only used by perf inject and the all others
passes 'false'.  Let's remove it from the function signature and add
__perf_session__new() to be called from perf inject directly.

This is a preparation of the change the pipe input/output.

Signed-off-by: Namhyung Kim 
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Ian Rogers 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20210719223153.1618812-2-namhyung@kernel.org
[ Fixed up some trivial conflicts as this patchset fell thru the cracks ;-( ]
Signed-off-by: Arnaldo Carvalho de Melo