Re: [PATCH 2/2] drivers/perf: arm_pmu: Fix NULL pointer dereference during probe

From: Kevin Hilman
Date: Wed Aug 31 2016 - 22:18:37 EST

Will Deacon <will.deacon@xxxxxxx> writes:

> On Sat, Aug 27, 2016 at 04:19:50PM +0000, Stefan Wahren wrote:
>> 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.
>> Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
>> Fixes: 7f1d642fbb5c ("drivers/perf: arm-pmu: Fix handling of SPI lacking \"interrupt-affinity\" property")
>> ---
>> drivers/perf/arm_pmu.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
> Thanks, these two look good to me. I'll queue them up as fixes and hopefully
> they'll land in -rc5.

FWIW, I tested this on bcm2835-rpi and verified it fixes the boot
problem in mainline.

Tested-by: Kevin Hilman <khilman@xxxxxxxxxxxx>