kernel/linux.git/tools/perf/util/debuginfo.c, branch v7.1-rc5

perf tools: Make more global variables static

2026-04-09T02:21:04+00:00

`make check` will run sparse on the perf code base. A frequent warning is "warning: symbol '...' was not declared. Should it be static?" Go through and make global definitions without declarations static. In some cases it is deliberate due to dlsym accessing the symbol, this change doesn't clean up the missing declarations for perf test suites. Sometimes things can opportunistically be made const. Making somethings static exposed unused functions warnings, so restructuring of ifdefs was necessary for that. These changes reduce the size of the perf binary by 568 bytes. Committer notes: Refreshed the patch, the original one fell thru the cracks, updated the size reduction. Remove the trace-event-scripting.c changes, break the build, noticed with container builds and with sashiko: https://sashiko.dev/#/patchset/20260401215306.2152898-1-acme%40kernel.org Also make two variables static to address another sashiko review comment: https://sashiko.dev/#/patchset/20260402001740.2220481-1-acme%40kernel.org Signed-off-by: Ian Rogers Acked-by: Ankur Arora Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Athira Rajeev Cc: Guo Ren Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Leo Yan Cc: Masami Hiramatsu Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Yujie Liu Signed-off-by: Arnaldo Carvalho de Melo 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 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 tools: Use symfs when opening debuginfo by path

2025-02-13T03:44:16+00:00

I found that it failed to load a binary using --symfs option. Say I have a binary in /home/user/prog/xxx and a perf data file with it. If I move them to a different machine and use --symfs, it tries to find the binary in some locations under symfs using dso__read_binary_type_filename(), but not the last one. ${symfs}/usr/lib/debug/home/user/prog/xxx.debug ${symfs}/usr/lib/debug/home/user/prog/xxx ${symfs}/home/user/prog/.debug/xxx /home/user/prog/xxx It should check ${symfs}/home/usr/prog/xxx. Let's fix it. Reviewed-by: Ian Rogers Acked-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20250212221445.437481-1-namhyung@kernel.org Signed-off-by: Namhyung Kim

perf tools: Add util/debuginfo.[ch] files

2023-11-10T12:03:54+00:00

Split debuginfo data structure and related functions into a separate file so that it can be used by other components than the probe-finder. Signed-off-by: Namhyung Kim Cc: Adrian Hunter Cc: Andi Kleen Cc: Ian Rogers Cc: Ingo Molnar Cc: Jiri Olsa Cc: Linus Torvalds Cc: Masami Hiramatsu (Google) Cc: Peter Zijlstra Cc: Stephane Eranian Cc: linux-toolchains@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Link: https://lore.kernel.org/r/20231110000012.3538610-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo