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 <dawei.li@xxxxxxxxxxxx>
---
drivers/perf/hisilicon/hisi_uncore_pmu.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c
index 04031450d5fe..06891d23b21c 100644
--- a/drivers/perf/hisilicon/hisi_uncore_pmu.c
+++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c
@@ -504,7 +504,7 @@ int hisi_uncore_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
{
struct hisi_pmu *hisi_pmu = hlist_entry_safe(node, struct hisi_pmu,
node);
- cpumask_t pmu_online_cpus;
+ cpumask_var_t pmu_online_cpus;
unsigned int target;
if (!cpumask_test_and_clear_cpu(cpu, &hisi_pmu->associated_cpus))
@@ -514,21 +514,26 @@ int hisi_uncore_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
if (hisi_pmu->on_cpu != cpu)
return 0;
+ if (!alloc_cpumask_var(&pmu_online_cpus, GFP_KERNEL))
+ return 0;
+
/* Give up ownership of the PMU */
hisi_pmu->on_cpu = -1;
/* Choose a new CPU to migrate ownership of the PMU to */
- cpumask_and(&pmu_online_cpus, &hisi_pmu->associated_cpus,
+ cpumask_and(pmu_online_cpus, &hisi_pmu->associated_cpus,
cpu_online_mask);
- target = cpumask_any_but(&pmu_online_cpus, cpu);
+ target = cpumask_any_but(pmu_online_cpus, cpu);
if (target >= nr_cpu_ids)
- return 0;
+ goto __free_cpumask;
perf_pmu_migrate_context(&hisi_pmu->pmu, cpu, target);
/* Use this CPU for event counting */
hisi_pmu->on_cpu = target;
WARN_ON(irq_set_affinity(hisi_pmu->irq, cpumask_of(target)));
+__free_cpumask:
+ free_cpumask_var(pmu_online_cpus);
return 0;
}
EXPORT_SYMBOL_GPL(hisi_uncore_pmu_offline_cpu);
--
2.27.0
