coresight: etb10: Do not call smp_processor_id from preemptible
authorSuzuki K Poulose <suzuki.poulose@arm.com>
Thu, 20 Jun 2019 22:12:36 +0000 (16:12 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 3 Jul 2019 19:15:33 +0000 (21:15 +0200)
commit730766bae3280a25d40ea76a53dc6342e84e6513
tree0b687dc2d4112f9728440c5cf52af1ad4dcb7268
parent024c1fd9dbcc1d8a847f1311f999d35783921b7f
coresight: etb10: Do not call smp_processor_id from preemptible

During a perf session we try to allocate buffers on the "node" associated
with the CPU the event is bound to. If it is not bound to a CPU, we
use the current CPU node, using smp_processor_id(). However this is unsafe
in a pre-emptible context and could generate the splats as below :

 BUG: using smp_processor_id() in preemptible [00000000] code: perf/2544

Use NUMA_NO_NODE hint instead of using the current node for events
not bound to CPUs.

Fixes: 2997aa4063d97fdb39 ("coresight: etb10: implementing AUX API")
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: stable <stable@vger.kernel.org> # 4.6+
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20190620221237.3536-5-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hwtracing/coresight/coresight-etb10.c