kernel/linux.git/tools/perf/util/dso.c, branch v6.18.22

perf tools: Get debug info of DSO properly

2026-03-04T12:19:24+00:00

[ Upstream commit 069e603d8248dac98b1ef2909e2f1c4169b9da11 ] The dso__debuginfo() just used the path name to open the file but it may be outdated. It should check build-ID and use the file in the build-ID cache if available rather than just using the path name. Let's factor out dso__get_filename() to avoid code duplicate. Fixes: 53a61a6ca279165d ("perf annotate: Add dso__debuginfo() helper") Reviewed-by: Ian Rogers Signed-off-by: Namhyung Kim Cc: Adrian Hunter 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 dso: Clean up read_symbol() error handling

2025-10-06T19:35:28+00:00

Ensure errno is set and return to caller for error handling. Unusually for perf the value isn't negated as expected by symbol__strerror_disassemble(). Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Andi Kleen Cc: Athira Rajeev Cc: Bill Wendling Cc: Charlie Jenkins Cc: Collin Funk Cc: Dmitriy Vyukov Cc: Dr. David Alan Gilbert Cc: Eric Biggers Cc: Haibo Xu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Justin Stitt Cc: Li Huafei Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Song Liu Cc: Stephen Brennan Signed-off-by: Arnaldo Carvalho de Melo

perf dso: Support BPF programs in dso__read_symbol()

2025-10-06T19:35:28+00:00

Set the buffer to the code in the BPF linear info. This enables BPF JIT code disassembly by LLVM and capstone. Move the common but minimal disassmble_bpf_image call to disassemble_objdump so that it is only called after falling back to the objdump option. Similarly move the disassmble_bpf function to disassemble_objdump and rename to disassmble_bpf_libbfd to make it clearer that this support relies on libbfd. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Andi Kleen Cc: Athira Rajeev Cc: Bill Wendling Cc: Charlie Jenkins Cc: Collin Funk Cc: Dmitriy Vyukov Cc: Dr. David Alan Gilbert Cc: Eric Biggers Cc: Haibo Xu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Justin Stitt Cc: Li Huafei Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Song Liu Cc: Stephen Brennan Signed-off-by: Arnaldo Carvalho de Melo

perf dso: Move read_symbol() from llvm/capstone to dso

2025-10-06T19:35:25+00:00

Move the read_symbol function to dso.h, make the return type const and add a mutable out_buf out parameter. In future changes this will allow a code pointer to be returned without necessary allocating memory. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Andi Kleen Cc: Athira Rajeev Cc: Bill Wendling Cc: Charlie Jenkins Cc: Collin Funk Cc: Dmitriy Vyukov Cc: Dr. David Alan Gilbert Cc: Eric Biggers Cc: Haibo Xu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Justin Stitt Cc: Li Huafei Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Peter Zijlstra Cc: Song Liu Cc: Stephen Brennan Signed-off-by: Arnaldo Carvalho de Melo

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 dso: With ref count checking, avoid dso_data holding dso live

2025-07-03T02:05:27+00:00

With the dso_data embedded in a dso there is a reference counted pointer to the dso rather than using container_of with reference count checking. This data can hold the dso live meaning that no dso__put ever deletes it. Add a check for this case and close the dso_data when it happens. There isn't an infinite loop as the dso_data clears the file descriptor prior to putting on the dso. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250624190326.2038704-5-irogers@google.com Signed-off-by: Namhyung Kim

perf dso: Minor refactor to allow clang's Wthread-safety analysis

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

The pattern: ``` if (x) { lock(...) } block1; if (x) { unlock(...) } ``` defeats clang's -Wthread-safety analysis where it complains of locks held on one path and not another. Add helper functions for "block1" then restructure as: ``` if (x) { lock(...); block1(); unlock(...); } else { block1(); } ``` 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/20250519224645.1810891-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf dso: Add support for reading the e_machine type for a dso

2025-03-21T05:58:02+00:00

For ELF file dsos read the e_machine from the ELF header. For kernel types assume the e_machine matches the perf tool. In other cases return EM_NONE. When reading from the ELF header use DSO__SWAP that may need dso->needs_swap initializing. Factor out dso__swap_init to allow this. Signed-off-by: Ian Rogers Reviewed-by: Namhyung Kim Acked-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/r/20250319050741.269828-7-irogers@google.com Signed-off-by: Namhyung Kim

perf dso: Use lock annotations to fix asan deadlock

2025-03-18T05:07:18+00:00

dso__list_del with address sanitizer and/or reference count checking will call dso__put that can call dso__data_close reentrantly trying to lock the dso__data_open_lock and deadlocking. Switch from pthread mutexes to perf's mutex so that lock checking is performed in debug builds. Add lock annotations that diagnosed the problem. Release the dso__data_open_lock around the dso__put to avoid the deadlock. Change the declaration of dso__data_get_fd to return a boolean, indicating the fd is valid and the lock is held, to make it compatible with the thread safety annotations as a try lock. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250318043151.137973-3-irogers@google.com Signed-off-by: Namhyung Kim