drivers/perf: arm_pmu: avoid CPU device_node reference leak

of_cpu_device_node_get increments the reference count on the CPU
device_node, so we must take care to of_node_put once we've finished
with it.

This patch fixes the perf IRQ probing code to avoid the leak.

Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 2365a32..be3755c 100644 (file)
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -823,9 +823,15 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu)
                }
 
                /* Now look up the logical CPU number */
-               for_each_possible_cpu(cpu)
-                       if (dn == of_cpu_device_node_get(cpu))
+               for_each_possible_cpu(cpu) {
+                       struct device_node *cpu_dn;
+
+                       cpu_dn = of_cpu_device_node_get(cpu);
+                       of_node_put(cpu_dn);
+
+                       if (dn == cpu_dn)
                                break;
+               }
 
                if (cpu >= nr_cpu_ids) {
                        pr_warn("Failed to find logical CPU for %s\n",