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| author | Suzuki K Poulose <suzuki.poulose@arm.com> | 2019-06-20 16:12:36 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-03 21:15:33 +0200 |
| commit | 730766bae3280a25d40ea76a53dc6342e84e6513 (patch) | |
| tree | 0b687dc2d4112f9728440c5cf52af1ad4dcb7268 /drivers/hwtracing/coresight | |
| parent | 024c1fd9dbcc1d8a847f1311f999d35783921b7f (diff) | |
| download | linux-730766bae3280a25d40ea76a53dc6342e84e6513.tar.gz linux-730766bae3280a25d40ea76a53dc6342e84e6513.tar.bz2 linux-730766bae3280a25d40ea76a53dc6342e84e6513.zip | |
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/coresight')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-etb10.c | 6 |
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) |