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/dwc_pcie_pmu.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/perf/dwc_pcie_pmu.c b/drivers/perf/dwc_pcie_pmu.c
index 957058ad0099..97037b6aaa97 100644
--- a/drivers/perf/dwc_pcie_pmu.c
+++ b/drivers/perf/dwc_pcie_pmu.c
@@ -690,33 +690,38 @@ static int dwc_pcie_pmu_offline_cpu(unsigned int cpu, struct hlist_node *cpuhp_n
{
struct dwc_pcie_pmu *pcie_pmu;
struct pci_dev *pdev;
- int node;
- cpumask_t mask;
unsigned int target;
+ cpumask_var_t mask;
+ int node;
pcie_pmu = hlist_entry_safe(cpuhp_node, struct dwc_pcie_pmu, cpuhp_node);
/* Nothing to do if this CPU doesn't own the PMU */
if (cpu != pcie_pmu->on_cpu)
return 0;
+ if (!alloc_cpumask_var(&mask, GFP_KERNEL))
+ return 0;
+
pcie_pmu->on_cpu = -1;
pdev = pcie_pmu->pdev;
node = dev_to_node(&pdev->dev);
- if (cpumask_and(&mask, cpumask_of_node(node), cpu_online_mask) &&
- cpumask_andnot(&mask, &mask, cpumask_of(cpu)))
- target = cpumask_any(&mask);
+ if (cpumask_and(mask, cpumask_of_node(node), cpu_online_mask) &&
+ cpumask_andnot(mask, mask, cpumask_of(cpu)))
+ target = cpumask_any(mask);
else
target = cpumask_any_but(cpu_online_mask, cpu);
if (target >= nr_cpu_ids) {
pci_err(pdev, "There is no CPU to set\n");
- return 0;
+ goto __free_cpumask;
}
/* This PMU does NOT support interrupt, just migrate context. */
perf_pmu_migrate_context(&pcie_pmu->pmu, cpu, target);
pcie_pmu->on_cpu = target;
+__free_cpumask:
+ free_cpumask_var(mask);
return 0;
}
--
2.27.0