* FAILED: patch "[PATCH] coresight: etb10: Do not call smp_processor_id from" failed to apply to 5.1-stable tree
@ 2019-07-12 9:05 gregkh
0 siblings, 0 replies; only message in thread
From: gregkh @ 2019-07-12 9:05 UTC (permalink / raw)
To: suzuki.poulose, gregkh, mathieu.poirier, stable; +Cc: stable
The patch below does not apply to the 5.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 730766bae3280a25d40ea76a53dc6342e84e6513 Mon Sep 17 00:00:00 2001
From: Suzuki K Poulose <suzuki.poulose@arm.com>
Date: Thu, 20 Jun 2019 16:12:36 -0600
Subject: [PATCH] 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>
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)
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2019-07-12 9:05 FAILED: patch "[PATCH] coresight: etb10: Do not call smp_processor_id from" failed to apply to 5.1-stable tree gregkh
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