drivers/perf: arm_pmu: Fix NULL pointer dereference during probe

Patch 7f1d642fbb5c ("drivers/perf: arm-pmu: Fix handling of SPI lacking
interrupt-affinity property") unintended also fixes perf_event support
for bcm2835 which doesn't have PMU interrupts. Unfortunately this change
introduce a NULL pointer dereference on bcm2835, because irq_is_percpu
always expected to be called with a valid IRQ. So fix this regression
by validating the IRQ before.

Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Fixes: 7f1d642fbb5c ("drivers/perf: arm-pmu: Fix handling of SPI lacking "interrupt-affinity" property")
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 1b48bf0..f5e1008 100644 (file)
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -970,7 +970,7 @@ static int of_pmu_irq_cfg(struct arm_pmu *pmu)
        if (cpumask_weight(&pmu->supported_cpus) == 0) {
                int irq = platform_get_irq(pdev, 0);
 
-               if (irq_is_percpu(irq)) {
+               if (irq >= 0 && irq_is_percpu(irq)) {
                        /* If using PPIs, check the affinity of the partition */
                        int ret;