diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2026-08-02 11:27:10 -0300 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2026-08-05 11:20:02 -0700 |
| commit | 60f2f5b7650bb8779af3087ef429fad4ed74a5c8 (patch) | |
| tree | ac3df4cde0fba1cefd9ed0afecc75f4c54230ed9 /tools | |
| parent | 01765b456f850aed7475b37111f1c50bf76aaf51 (diff) | |
perf header: Use write lock when translating BPF prog info pointers
write_bpf_prog_info() holds a read lock while temporarily mutating
info_linear via bpil_addr_to_offs()/bpil_offs_to_addr(). Between these
two calls, the pointers in info_linear contain file offsets instead of
heap addresses. Concurrent readers holding the same read lock see the
file offsets and dereference them as pointers.
Use down_write()/up_write() instead of down_read()/up_read() to exclude
concurrent readers during the addr-to-offset-to-addr translation window.
Fixes: 63ac7968a1fb ("perf bpf: Save bpf_prog_info information as headers to perf.data")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/perf/util/header.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index e90e541f546b..7db7da090a1e 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -1120,7 +1120,8 @@ static int write_bpf_prog_info(struct feat_fd *ff __maybe_unused, struct rb_node *next; int ret = 0; - down_read(&env->bpf_progs.lock); + /* write lock: bpil_addr_to_offs() temporarily mutates info_linear */ + down_write(&env->bpf_progs.lock); ret = do_write(ff, &env->bpf_progs.infos_cnt, sizeof(env->bpf_progs.infos_cnt)); @@ -1150,7 +1151,7 @@ static int write_bpf_prog_info(struct feat_fd *ff __maybe_unused, goto out; } out: - up_read(&env->bpf_progs.lock); + up_write(&env->bpf_progs.lock); return ret; #else pr_err("ERROR: Trying to write bpf_prog_info without libbpf support.\n"); |