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/alibaba_uncore_drw_pmu.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/perf/alibaba_uncore_drw_pmu.c b/drivers/perf/alibaba_uncore_drw_pmu.c
index a9277dcf90ce..251f0a2dee84 100644
--- a/drivers/perf/alibaba_uncore_drw_pmu.c
+++ b/drivers/perf/alibaba_uncore_drw_pmu.c
@@ -743,25 +743,28 @@ static void ali_drw_pmu_remove(struct platform_device *pdev)
static int ali_drw_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
{
+ cpumask_var_t node_online_cpus;
struct ali_drw_pmu_irq *irq;
struct ali_drw_pmu *drw_pmu;
unsigned int target;
int ret;
- cpumask_t node_online_cpus;
irq = hlist_entry_safe(node, struct ali_drw_pmu_irq, node);
if (cpu != irq->cpu)
return 0;
- ret = cpumask_and(&node_online_cpus,
+ if (!alloc_cpumask_var(&node_online_cpus, GFP_KERNEL))
+ return 0;
+
+ ret = cpumask_and(node_online_cpus,
cpumask_of_node(cpu_to_node(cpu)), cpu_online_mask);
if (ret)
- target = cpumask_any_but(&node_online_cpus, cpu);
+ target = cpumask_any_but(node_online_cpus, cpu);
else
target = cpumask_any_but(cpu_online_mask, cpu);
if (target >= nr_cpu_ids)
- return 0;
+ goto __free_cpumask;
/* We're only reading, but this isn't the place to be involving RCU */
mutex_lock(&ali_drw_pmu_irqs_lock);
@@ -772,6 +775,8 @@ static int ali_drw_pmu_offline_cpu(unsigned int cpu, struct hlist_node *node)
WARN_ON(irq_set_affinity_hint(irq->irq_num, cpumask_of(target)));
irq->cpu = target;
+__free_cpumask:
+ free_cpumask_var(node_online_cpus);
return 0;
}
--
2.27.0
