diff options
| author | Ian Rogers <irogers@google.com> | 2025-12-04 00:47:01 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-01-08 12:14:12 +0300 |
| commit | 6b4f044d9cd8a61cfd6ec1e9774ac48b29fcc646 (patch) | |
| tree | 83aec888216ef44e9f85c7b0a746d50c71557d9e /tools/lib | |
| parent | 3f7a5d52a4ea9cc6a4a0dfd19e003fb5e886438d (diff) | |
| download | linux-6b4f044d9cd8a61cfd6ec1e9774ac48b29fcc646.tar.xz | |
libperf cpumap: Fix perf_cpu_map__max for an empty/NULL map
[ Upstream commit a0a4173631bfcfd3520192c0a61cf911d6a52c3a ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools/lib')
| -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 cae799ad44e1..e5938b91199f 100644 --- a/tools/lib/perf/cpumap.c +++ b/tools/lib/perf/cpumap.c @@ -409,10 +409,12 @@ 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'. */ |