The bug is here: return cluster;

The list iterator value 'cluster' will *always* be set and non-NULL by list_for_each_entry(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element is found.

To fix the bug, return 'cluster' when found, otherwise return NULL.

Cc: stable@vger.kernel.org Fixes: 21bdbb7102ede ("perf: add qcom l2 cache perf events driver") Signed-off-by: Xiaomeng Tong xiam0nd.tong@gmail.com --- drivers/perf/qcom_l2_pmu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/perf/qcom_l2_pmu.c b/drivers/perf/qcom_l2_pmu.c index 7640491aab12..30234c261b05 100644 --- a/drivers/perf/qcom_l2_pmu.c +++ b/drivers/perf/qcom_l2_pmu.c @@ -736,7 +736,7 @@ static struct cluster_pmu *l2_cache_associate_cpu_with_cluster( { u64 mpidr; int cpu_cluster_id; - struct cluster_pmu *cluster = NULL; + struct cluster_pmu *cluster;

/* * This assumes that the cluster_id is in MPIDR[aff1] for @@ -758,10 +758,10 @@ static struct cluster_pmu *l2_cache_associate_cpu_with_cluster( cluster->cluster_id); cpumask_set_cpu(cpu, &cluster->cluster_cpus); *per_cpu_ptr(l2cache_pmu->pmu_cluster, cpu) = cluster; - break; + return cluster; }

- return cluster; + return NULL; }

static int l2cache_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)