From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: stable@vger.kernel.org
Cc: suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org,
mathieu.poirier@linaro.org, gregkh@linuxfoundation.org,
Sasha Levin <sashal@kernel.org>,
linux-kernel@vger.kernel.org
Subject: [stable] [PATCH 2/2] coresight: tmc-etf: Do not call smp_processor_id from preemptible
Date: Wed, 8 Jan 2020 11:05:41 +0000 [thread overview]
Message-ID: <20200108110541.318672-2-suzuki.poulose@arm.com> (raw)
In-Reply-To: <20200108110541.318672-1-suzuki.poulose@arm.com>
[ Upstream commit 024c1fd9dbcc1d8a847f1311f999d35783921b7f ]
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
caller is tmc_alloc_etf_buffer+0x5c/0x60
CPU: 2 PID: 2544 Comm: perf Not tainted 5.1.0-rc6-147786-g116841e #344
Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Feb 1 2019
Call trace:
dump_backtrace+0x0/0x150
show_stack+0x14/0x20
dump_stack+0x9c/0xc4
debug_smp_processor_id+0x10c/0x110
tmc_alloc_etf_buffer+0x5c/0x60
etm_setup_aux+0x1c4/0x230
rb_alloc_aux+0x1b8/0x2b8
perf_mmap+0x35c/0x478
mmap_region+0x34c/0x4f0
do_mmap+0x2d8/0x418
vm_mmap_pgoff+0xd0/0xf8
ksys_mmap_pgoff+0x88/0xf8
__arm64_sys_mmap+0x28/0x38
el0_svc_handler+0xd8/0x138
el0_svc+0x8/0xc
Use NUMA_NO_NODE hint instead of using the current node for events
not bound to CPUs.
Fixes: 2e499bbc1a929ac ("coresight: tmc: implementing TMC-ETF AUX space API")
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: stable <stable@vger.kernel.org> # v4.9 to v4.19
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20190620221237.3536-4-mathieu.poirier@linaro.org
---
drivers/hwtracing/coresight/coresight-tmc-etf.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index e31061308e19..e90af39283b1 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -304,9 +304,7 @@ static void *tmc_alloc_etf_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);
/* Allocate memory structure for interaction with Perf */
buf = kzalloc_node(sizeof(struct cs_buffers), GFP_KERNEL, node);
--
2.24.1
next prev parent reply other threads:[~2020-01-08 11:05 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-08 11:05 [stable] [PATCH 1/2] coresight: etb10: Do not call smp_processor_id from preemptible Suzuki K Poulose
2020-01-08 11:05 ` Suzuki K Poulose [this message]
2020-01-09 14:35 ` Sasha Levin
2020-01-09 14:36 ` Suzuki Kuruppassery Poulose
2020-01-15 15:11 ` Greg KH
2020-01-15 16:44 ` Suzuki Kuruppassery Poulose
2020-01-15 17:21 ` Greg KH
2020-01-15 17:28 ` Suzuki Kuruppassery Poulose
2020-01-28 8:15 ` Greg KH
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