From: Ganapatrao Kulkarni <redacted>

On some platforms(arm/arm64) which uses cpus map to get corresponding
cpuid string, cpuid can be NULL for PMUs other than CORE PMUs.  Adding
check for NULL cpuid in function perf_pmu__find_map to avoid
segmentation fault.

Signed-off-by: Ganapatrao Kulkarni <redacted>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ganapatrao Kulkarni <redacted>
Cc: Jayachandran C <redacted>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <redacted>
Cc: Shaokun Zhang <redacted>
Cc: Will Deacon <redacted>
Cc: linux-arm-kernel at lists.infradead.org
Link: http://lkml.kernel.org/r/20171016183222.25750-6-ganapatrao.kulkarni at cavium.com
Signed-off-by: Arnaldo Carvalho de Melo <redacted>
---
 tools/perf/util/pmu.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 732ff579ec65..8b7c151579c0 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c

@@ -601,6 +601,12 @@ struct pmu_events_map *perf_pmu__find_map(struct perf_pmu *pmu)
 	char *cpuid = perf_pmu__getcpuid(pmu);
 	int i;
 
+	/* on some platforms which uses cpus map, cpuid can be NULL for
+	 * PMUs other than CORE PMUs.
+	 */
+	if (!cpuid)
+		return NULL;
+
 	i = 0;
 	for (;;) {
 		map = &pmu_events_map[i++];

-- 
2.13.6