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| author | Namhyung Kim <namhyung@kernel.org> | 2024-11-26 19:13:31 -0800 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2024-12-02 12:36:20 -0800 |
| commit | 23c44f6c83257923b179461694edcf62749bedd5 (patch) | |
| tree | 8e0f3bb9f50acae48f0562c5828eee5d49b3995e /tools/perf | |
| parent | 40384c840ea1944d7c5a392e8975ed088ecf0b37 (diff) | |
| download | lwn-23c44f6c83257923b179461694edcf62749bedd5.tar.gz lwn-23c44f6c83257923b179461694edcf62749bedd5.zip | |
perf tools: Fix build-id event recording
The build-id events written at the end of the record session are broken
due to unexpected data. The write_buildid() writes the fixed length
event first and then variable length filename.
But a recent change made it write more data in the padding area
accidentally. So readers of the event see zero-filled data for the
next entry and treat it incorrectly. This resulted in wrong kernel
symbols because the kernel DSO loaded a random vmlinux image in the
path as it didn't have a valid build-id.
Fixes: ae39ba16554e ("perf inject: Fix build ID injection")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/Z0aRFFW9xMh3mqKB@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Diffstat (limited to 'tools/perf')
| -rw-r--r-- | tools/perf/util/build-id.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index 8982f68e7230..e763e8d99a43 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -277,7 +277,7 @@ static int write_buildid(const char *name, size_t name_len, struct build_id *bid struct perf_record_header_build_id b; size_t len; - len = sizeof(b) + name_len + 1; + len = name_len + 1; len = PERF_ALIGN(len, sizeof(u64)); memset(&b, 0, sizeof(b)); @@ -286,7 +286,7 @@ static int write_buildid(const char *name, size_t name_len, struct build_id *bid misc |= PERF_RECORD_MISC_BUILD_ID_SIZE; b.pid = pid; b.header.misc = misc; - b.header.size = len; + b.header.size = sizeof(b) + len; err = do_write(fd, &b, sizeof(b)); if (err < 0) |