| Message ID | 20190619195318.19254-24-mathieu.poirier@linaro.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 730766bae3280a25d40ea76a53dc6342e84e6513 |
| Headers | show |
| Series | coresight: next v5.2-rc5 (V2) | expand |
On Wed, Jun 19, 2019 at 01:53:13PM -0600, Mathieu Poirier wrote: > From: Suzuki K Poulose <suzuki.poulose@arm.com> > > 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> > Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> > --- > drivers/hwtracing/coresight/coresight-etb10.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) Again, 5.2 and stable.
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)