drivers/perf: arm_pmu: Fix reference count of a device_node in of_pmu_irq_cfg

The only function called by of_pmu_irq_cfg that will increment the
reference count on dn is of_parse_phandle.

Each time we successfully parse a possible CPU from an
interrupt-affinity property, we increment the refcount of that CPU node
once via of_parse_handle. After validating the CPU is possible, we
decrement the refcount once. Subsequently, we decrement the refcount
again, either as part of an early break if we don't have a matching SPI,
or as part of the end of the loop body.

This will lead to decrementing twice the refcounnt.
Remove the second pairs of call to of_node_put as nobody is using dn
between the first and second call to of_node_put.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index f2d01d4..6401f0c 100644 (file)
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -950,17 +950,14 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu)
 
                /* For SPIs, we need to track the affinity per IRQ */
                if (using_spi) {
-                       if (i >= pdev->num_resources) {
-                               of_node_put(dn);
+                       if (i >= pdev->num_resources)
                                break;
-                       }
 
                        irqs[i] = cpu;
                }
 
                /* Keep track of the CPUs containing this PMU type */
                cpumask_set_cpu(cpu, &pmu->supported_cpus);
-               of_node_put(dn);
                i++;
        } while (1);