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

perf symbol: Fix ENOENT case for filename__read_build_id

2026-07-24T14:17:26+00:00

commit 5c5f6fe32df2edb4f72bdca62ec2b9f20b7c5ba4 upstream.

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 
Signed-off-by: Greg Kroah-Hartman

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

2026-07-24T14:16:27+00:00

[ Upstream commit 834ebb5678d75d844f5d4f44ede78724d8c96630 ]

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 
Stable-dep-of: f973e52a9977 ("perf dso: Fix heap overflow in dso__get_filename() on decompressed path")
Signed-off-by: Sasha Levin

perf annotate: Fix BUILD_NONDISTRO=1 missing args->ms conversions to pointer

2026-03-04T12:19:26+00:00

[ Upstream commit dda5f926a1006c735b00ed5c27291fce64236656 ]

Fix a few missing conversions to pointer in the usage of 'struct
annotate_args' 'ms' member in symbol__disassemble_bpf_libbfd().

Fixes: 00419892bac28bf1 ("perf annotate: Fix args leak of map_symbol")
Reviewed-by: Ian Rogers 
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf libbfd: Ensure libbfd is initialized prior to use

2025-11-13T20:55:19+00:00

Multiple threads may be creating and destroying BFD objects in
situations like `perf top`.

Without appropriate initialization crashes may occur during libbfd's
cache management.

BFD's locks require recursive mutexes, add support for these.

Committer testing:

This happens only when building with 'make BUILD_NONDISTRO=1' and having
the binutils-devel package (or equivalent) installed, i.e. linking with
binutils devel files, an opt-in perf build.

Before:

  root@x1:~# perf top
  perf: Segmentation fault
  -------- backtrace --------
  
  root@x1:~#

After this patch it works as before.

Closes: https://lore.kernel.org/lkml/aQt66zhfxSA80xwt@gentoo.org/
Fixes: 95931d9a594dd0b5 ("perf libbfd: Move libbfd functionality to its own file")
Reported-by: Guilherme Amadio 
Signed-off-by: Ian Rogers 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
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 libbfd: Move libbfd functionality to its own file

2025-10-02T18:39:44+00:00

Move symbolization and srcline libbfd dependencies to a separate
libbfd.c. This mirrors moving llvm and capstone code. While this code
is deprecated as it is part of BUILD_NONDISTRO license incompatible
code, moving the code to its own file minimizes disruption in the main
files.

disasm_bpf.c is moved to libbfd.c also except for
symbol__disassemble_bpf_image which is currently more of a placeholder
function rather than something that provides disassembly support.

demangle-cxx.cpp code isn't migrated as it is very limited.

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: Mark Rutland 
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