For CONFIG_CPUMASK_OFFSTACK=y kernel, explicit allocation of cpumask
variable on stack is not recommended since it can cause potential stack
overflow.
Instead, kernel code should always use *cpumask_var API(s) to allocate
cpumask var in config- neutral way, leaving allocation strategy to
CONFIG_CPUMASK_OFFSTACK.
Use *cpumask_var API(s) to address it.
Signed-off-by: Dawei Li <[email protected]>
---
drivers/perf/qcom_l2_pmu.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/perf/qcom_l2_pmu.c b/drivers/perf/qcom_l2_pmu.c
index 148df5ae8ef8..8fe0c7557521 100644
--- a/drivers/perf/qcom_l2_pmu.c
+++ b/drivers/perf/qcom_l2_pmu.c
@@ -801,9 +801,9 @@ static int l2cache_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)
static int l2cache_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
{
- struct cluster_pmu *cluster;
+ cpumask_var_t cluster_online_cpus;
struct l2cache_pmu *l2cache_pmu;
- cpumask_t cluster_online_cpus;
+ struct cluster_pmu *cluster;
unsigned int target;
l2cache_pmu = hlist_entry_safe(node, struct l2cache_pmu, node);
@@ -815,17 +815,20 @@ static int l2cache_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
if (cluster->on_cpu != cpu)
return 0;
+ if (!alloc_cpumask_var(&cluster_online_cpus, GFP_KERNEL))
+ return 0;
+
/* Give up ownership of cluster */
cpumask_clear_cpu(cpu, &l2cache_pmu->cpumask);
cluster->on_cpu = -1;
/* Any other CPU for this cluster which is still online */
- cpumask_and(&cluster_online_cpus, &cluster->cluster_cpus,
+ cpumask_and(cluster_online_cpus, &cluster->cluster_cpus,
cpu_online_mask);
- target = cpumask_any_but(&cluster_online_cpus, cpu);
+ target = cpumask_any_but(cluster_online_cpus, cpu);
if (target >= nr_cpu_ids) {
disable_irq(cluster->irq);
- return 0;
+ goto __free_cpumask;
}
perf_pmu_migrate_context(&l2cache_pmu->pmu, cpu, target);
@@ -833,6 +836,8 @@ static int l2cache_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
cpumask_set_cpu(target, &l2cache_pmu->cpumask);
WARN_ON(irq_set_affinity(cluster->irq, cpumask_of(target)));
+__free_cpumask:
+ free_cpumask_var(cluster_online_cpus);
return 0;
}
--
2.27.0