diff options
| author | Ian Rogers <irogers@google.com> | 2025-12-03 13:47:01 -0800 |
|---|---|---|
| committer | Namhyung Kim <namhyung@kernel.org> | 2025-12-04 00:36:14 -0800 |
| commit | a0a4173631bfcfd3520192c0a61cf911d6a52c3a (patch) | |
| tree | ad012fd6b8169e7a1af4d9e3ccf58ae4301937d9 | |
| parent | 6744c0b182c1f371135bc3f4e62b96ad884c9f89 (diff) | |
libperf cpumap: Fix perf_cpu_map__max for an empty/NULL map
Passing an empty map to perf_cpu_map__max triggered a SEGV. Explicitly
test for the empty map.
Reported-by: Ingo Molnar <mingo@kernel.org>
Closes: https://lore.kernel.org/linux-perf-users/aSwt7yzFjVJCEmVp@gmail.com/
Tested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
| -rw-r--r-- | tools/lib/perf/cpumap.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c index 7e88417ba84d..4160e7d2e120 100644 --- a/tools/lib/perf/cpumap.c +++ b/tools/lib/perf/cpumap.c @@ -368,10 +368,12 @@ struct perf_cpu perf_cpu_map__max(const struct perf_cpu_map *map) .cpu = -1 }; - // cpu_map__trim_new() qsort()s it, cpu_map__default_new() sorts it as well. - return __perf_cpu_map__nr(map) > 0 - ? __perf_cpu_map__cpu(map, __perf_cpu_map__nr(map) - 1) - : result; + if (!map) + return result; + + // The CPUs are always sorted and nr is always > 0 as 0 length map is + // encoded as NULL. + return __perf_cpu_map__cpu(map, __perf_cpu_map__nr(map) - 1); } /** Is 'b' a subset of 'a'. */ |