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authorSuzuki K Poulose <suzuki.poulose@arm.com>2019-06-20 16:12:36 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-01-29 16:43:23 +0100
commit63906caff4a8a24e6c5a55c1b81ec0d308a152fd (patch)
tree24a1289bcb5d2c423dc1313be21a9b5f8aa71bc3
parent03e520dcdc0ab793074503bc1422ccc948aad254 (diff)
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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>
-rw-r--r--drivers/hwtracing/coresight/coresight-etb10.c4
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 0dad8626bcfb..6cf28b049635 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -275,9 +275,7 @@ static void *etb_alloc_buffer(struct coresight_device *csdev, int cpu,
int node;
struct cs_buffers *buf;
- if (cpu == -1)
- cpu = smp_processor_id();
- node = cpu_to_node(cpu);
+ node = (cpu == -1) ? NUMA_NO_NODE : cpu_to_node(cpu);
buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
if (!buf)