diff options
| author | Ian Rogers <irogers@google.com> | 2025-09-14 11:24:37 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2025-10-02 15:02:47 -0300 |
| commit | 8dc364fa484df22d301a16148d1b356931d0cbb0 (patch) | |
| tree | a4ead39f5a56ce187c9a7ae480a20fef6eb42079 | |
| parent | de1111f91a7a681303265938c2ad32f5ec3f21b7 (diff) | |
libperf mmap: In user mmap rdpmc avoid undefined behavior
A shift left of a signed 64-bit s64 may overflow and result in
undefined behavior caught by ubsan. Switch to a u64 instead.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/lib/perf/mmap.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/tools/lib/perf/mmap.c b/tools/lib/perf/mmap.c index c1a51d925e0e..ec124eb0ec0a 100644 --- a/tools/lib/perf/mmap.c +++ b/tools/lib/perf/mmap.c @@ -508,7 +508,7 @@ int perf_mmap__read_self(struct perf_mmap *map, struct perf_counts_values *count idx = READ_ONCE(pc->index); cnt = READ_ONCE(pc->offset); if (pc->cap_user_rdpmc && idx) { - s64 evcnt = read_perf_counter(idx - 1); + u64 evcnt = read_perf_counter(idx - 1); u16 width = READ_ONCE(pc->pmc_width); evcnt <<= 64 - width; |