kernel/linux.git/tools/perf/util/dsos.c, branch linux-7.1.y

perf tools: Replace basename() calls with perf_basename()

2026-04-09T02:21:05+00:00

As noticed in a sashiko review for a patch adding a missing libgen.h in a file using basename(): https://sashiko.dev/#/patchset/20260402001740.2220481-1-acme%40kernel.org So avoid these subtleties and instead reuse the gnu_basename() function we had in srcline.c, renaming it to perf_basename() and replace basename() calls with it, simplifying several cases by removing now needless strdups. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim

perf tools: prevent null dsos from being added

2026-04-02T19:51:10+00:00

When sorting the dso array we sometimes get a crash due to null comparisons in comparator functions. So prevent __dsos__add from adding null to the dso array to avoid out-of-memory related errors. Signed-off-by: Anubhav Shelat Reviewed-by: Ian Rogers 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 dso: Move build_id to dso_id

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

The dso_id previously contained the major, minor, inode and inode generation information from a mmap2 event - the inode generation would be zero when reading from /proc/pid/maps. The build_id was in the dso. With build ID mmap2 events these fields wouldn't be initialized which would largely mean the special empty case where any dso would match for equality. This isn't desirable as if a dso is replaced we want the comparison to yield a difference. To support detecting the difference between DSOs based on build_id, move the build_id out of the DSO and into the dso_id. The dso_id is also stored in the DSO so nothing is lost. Capture in the dso_id what parts have been initialized and rename dso_id__inject to dso_id__improve_id so that it is clear the dso_id is being improved upon with additional information. With the build_id in the dso_id, use memcmp to compare for equality. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250724163302.596743-7-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 rwsem: Add clang's -Wthread-safety annotations

2025-05-21T18:07:13+00:00

Add annotations used by clang's -Wthread-safety. Fix dsos compilation errors caused by a lock of annotations. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Athira Rajeev Cc: Bill Wendling Cc: Chaitanya S Prakash Cc: Fei Lang Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Justin Stitt Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Stephen Brennan Link: https://lore.kernel.org/r/20250519224645.1810891-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf dso: Constify dso_id

2024-08-19T17:52:13+00:00

The passed dso_id is copied and so is never an out argument. Remove its mutability. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Anne Macedo Cc: Arnd Bergmann Cc: Athira Rajeev Cc: Casey Chen Cc: Chaitanya S Prakash Cc: Colin Ian King Cc: Dominique Martinet Cc: Ingo Molnar Cc: James Clark Cc: Jann Horn Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Masahiro Yamada Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sun Haiyong Cc: Weilin Wang Cc: Yang Jihong Cc: Yunseong Kim Cc: Ze Gao Link: https://lore.kernel.org/r/20240817064442.2152089-5-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf dsos: When adding a dso into sorted dsos maintain the sort order

2024-07-03T22:02:53+00:00

dsos__add would add at the end of the dso array possibly requiring a later find to re-sort the array. Patterns of find then add were becoming O(n*log n) due to the sorts. Change the add routine to be O(n) rather than O(1) but to maintain the sorted-ness of the dsos array so that later finds don't need the O(n*log n) sort. Fixes: 3f4ac23a9908 ("perf dsos: Switch backing storage to array from rbtree/list") Reported-by: Namhyung Kim Signed-off-by: Ian Rogers Cc: Steinar Gunderson Cc: Athira Rajeev Cc: Matt Fleming Link: https://lore.kernel.org/r/20240703172117.810918-3-irogers@google.com Signed-off-by: Namhyung Kim

perf tools: Fix a compiler warning of NULL pointer

2024-06-25T18:06:20+00:00

A compiler warning on the second argument of bsearch() should not be NULL, but there's a case we might pass it. Let's return early if we don't have any DSOs to search in __dsos__find_by_longname_id(). util/dsos.c:184:8: runtime error: null pointer passed as argument 2, which is declared to never be null Reported-by: kernel test robot Reviewed-by: Kan Liang Closes: https://lore.kernel.org/oe-lkp/202406180932.84be448c-oliver.sang@intel.com Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240621170528.608772-4-namhyung@kernel.org