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authorSuzuki K Poulose <suzuki.poulose@arm.com>2019-06-20 16:12:36 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-07-03 21:15:33 +0200
commit730766bae3280a25d40ea76a53dc6342e84e6513 (patch)
tree0b687dc2d4112f9728440c5cf52af1ad4dcb7268 /drivers/hwtracing
parent024c1fd9dbcc1d8a847f1311f999d35783921b7f (diff)
downloadlinux-730766bae3280a25d40ea76a53dc6342e84e6513.tar.bz2
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>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/coresight/coresight-etb10.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index d5b9edecf76e..3810290e6d07 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -374,12 +374,10 @@ static void *etb_alloc_buffer(struct coresight_device *csdev,
struct perf_event *event, void **pages,
int nr_pages, bool overwrite)
{
- int node, cpu = event->cpu;
+ int node;
struct cs_buffers *buf;
- if (cpu == -1)
- cpu = smp_processor_id();
- node = cpu_to_node(cpu);
+ node = (event->cpu == -1) ? NUMA_NO_NODE : cpu_to_node(event->cpu);
buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
if (!buf)