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, 29 Jan 2020 09:24:40 +0000 (10:24 +0100)
commit93897ce10d934f3d5819a7fa10b926f4cf67845f
tree8870c65b214153487dc9d636adf9dd41b6480e88
parent564907b7713e3333c847c3eefe321ed354d56917
coresight: etb10: Do not call smp_processor_id from preemptible

commit 730766bae3280a25d40ea76a53dc6342e84e6513 upstream.

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