* [PATCH] coresight: tpdm: initialize spinlock before exposing sysfs
@ 2026-08-25 2:06 yingchao
2026-08-25 3:09 ` Jie Gan
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: yingchao @ 2026-08-25 2:06 UTC (permalink / raw)
To: Suzuki K Poulose, Alexander Shishkin
Cc: Mike Leach, James Clark, Leo Yan, Mao Jinlong, Tao Zhang,
jinlong.mao, qinyungao, coresight, linux-arm-kernel,
linux-kernel, Yingchao Deng
From: Yingchao Deng <dengyingchao@kylinsec.com.cn>
tpdm_probe() initializes drvdata->spinlock after coresight_register(), but
the sysfs attributes registered by coresight_register() use the spinlock.
This exposes a window where a concurrent sysfs write can lock an
uninitialized spinlock.
Initialize the spinlock before coresight_register().
Fixes: b3c71626a933 ("Coresight: Add coresight TPDM source driver")
Signed-off-by: Yingchao Deng <dengyingchao@kylinsec.com.cn>
---
drivers/hwtracing/coresight/coresight-tpdm.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 8464edbba2d4..50d1351772b9 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -1457,12 +1457,12 @@ static int tpdm_probe(struct device *dev, struct resource *res)
desc.groups = tpdm_attr_grps;
else
desc.groups = static_tpdm_attr_grps;
+ spin_lock_init(&drvdata->spinlock);
+
drvdata->csdev = coresight_register(&desc);
if (IS_ERR(drvdata->csdev))
return PTR_ERR(drvdata->csdev);
- spin_lock_init(&drvdata->spinlock);
-
return 0;
}
--
2.33.0
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] coresight: tpdm: initialize spinlock before exposing sysfs
2026-08-25 2:06 [PATCH] coresight: tpdm: initialize spinlock before exposing sysfs yingchao
@ 2026-08-25 3:09 ` Jie Gan
2026-09-07 3:08 ` yingchao deng
2026-09-08 16:18 ` Leo Yan
2 siblings, 0 replies; 4+ messages in thread
From: Jie Gan @ 2026-08-25 3:09 UTC (permalink / raw)
To: yingchao, Suzuki K Poulose, Alexander Shishkin
Cc: Mike Leach, James Clark, Leo Yan, Mao Jinlong, Tao Zhang,
jinlong.mao, qinyungao, coresight, linux-arm-kernel,
linux-kernel
On 8/25/2026 10:06 AM, yingchao wrote:
> From: Yingchao Deng <dengyingchao@kylinsec.com.cn>
>
> tpdm_probe() initializes drvdata->spinlock after coresight_register(), but
> the sysfs attributes registered by coresight_register() use the spinlock.
> This exposes a window where a concurrent sysfs write can lock an
> uninitialized spinlock.
>
There is only a very small window during which users have a chance to
access the sysfs nodes. But still worthy to fix it.
Reviewed-by: Jie Gan <jie.gan@oss.qualcomm.com>
> Initialize the spinlock before coresight_register().
>
> Fixes: b3c71626a933 ("Coresight: Add coresight TPDM source driver")
> Signed-off-by: Yingchao Deng <dengyingchao@kylinsec.com.cn>
> ---
> drivers/hwtracing/coresight/coresight-tpdm.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
> index 8464edbba2d4..50d1351772b9 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
> @@ -1457,12 +1457,12 @@ static int tpdm_probe(struct device *dev, struct resource *res)
> desc.groups = tpdm_attr_grps;
> else
> desc.groups = static_tpdm_attr_grps;
> + spin_lock_init(&drvdata->spinlock);
> +
> drvdata->csdev = coresight_register(&desc);
> if (IS_ERR(drvdata->csdev))
> return PTR_ERR(drvdata->csdev);
>
> - spin_lock_init(&drvdata->spinlock);
> -
> return 0;
> }
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] coresight: tpdm: initialize spinlock before exposing sysfs
2026-08-25 2:06 [PATCH] coresight: tpdm: initialize spinlock before exposing sysfs yingchao
2026-08-25 3:09 ` Jie Gan
@ 2026-09-07 3:08 ` yingchao deng
2026-09-08 16:18 ` Leo Yan
2 siblings, 0 replies; 4+ messages in thread
From: yingchao deng @ 2026-09-07 3:08 UTC (permalink / raw)
To: Suzuki K Poulose, Alexander Shishkin, Mike Leach, James Clark, Leo Yan
Cc: Mao Jinlong, Tao Zhang, jinlong.mao, qinyungao, coresight,
linux-arm-kernel, linux-kernel, Jie Gan
Gentle reminder
On 25/08/2026 10:06, yingchao wrote:
> From: Yingchao Deng <dengyingchao@kylinsec.com.cn>
>
> tpdm_probe() initializes drvdata->spinlock after coresight_register(), but
> the sysfs attributes registered by coresight_register() use the spinlock.
> This exposes a window where a concurrent sysfs write can lock an
> uninitialized spinlock.
>
> Initialize the spinlock before coresight_register().
>
> Fixes: b3c71626a933 ("Coresight: Add coresight TPDM source driver")
> Signed-off-by: Yingchao Deng <dengyingchao@kylinsec.com.cn>
> ---
> drivers/hwtracing/coresight/coresight-tpdm.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
> index 8464edbba2d4..50d1351772b9 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
> @@ -1457,12 +1457,12 @@ static int tpdm_probe(struct device *dev, struct resource *res)
> desc.groups = tpdm_attr_grps;
> else
> desc.groups = static_tpdm_attr_grps;
> + spin_lock_init(&drvdata->spinlock);
> +
> drvdata->csdev = coresight_register(&desc);
> if (IS_ERR(drvdata->csdev))
> return PTR_ERR(drvdata->csdev);
>
> - spin_lock_init(&drvdata->spinlock);
> -
> return 0;
> }
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] coresight: tpdm: initialize spinlock before exposing sysfs
2026-08-25 2:06 [PATCH] coresight: tpdm: initialize spinlock before exposing sysfs yingchao
2026-08-25 3:09 ` Jie Gan
2026-09-07 3:08 ` yingchao deng
@ 2026-09-08 16:18 ` Leo Yan
2 siblings, 0 replies; 4+ messages in thread
From: Leo Yan @ 2026-09-08 16:18 UTC (permalink / raw)
To: yingchao
Cc: Suzuki K Poulose, Alexander Shishkin, Mike Leach, James Clark,
Mao Jinlong, Tao Zhang, jinlong.mao, qinyungao, coresight,
linux-arm-kernel, linux-kernel
On Tue, Aug 25, 2026 at 10:06:47AM +0800, yingchao wrote:
> From: Yingchao Deng <dengyingchao@kylinsec.com.cn>
>
> tpdm_probe() initializes drvdata->spinlock after coresight_register(), but
> the sysfs attributes registered by coresight_register() use the spinlock.
> This exposes a window where a concurrent sysfs write can lock an
> uninitialized spinlock.
>
> Initialize the spinlock before coresight_register().
>
> Fixes: b3c71626a933 ("Coresight: Add coresight TPDM source driver")
> Signed-off-by: Yingchao Deng <dengyingchao@kylinsec.com.cn>
Reviewed-by: Leo Yan <leo.yan@arm.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-09-08 16:18 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2026-08-25 2:06 [PATCH] coresight: tpdm: initialize spinlock before exposing sysfs yingchao
2026-08-25 3:09 ` Jie Gan
2026-09-07 3:08 ` yingchao deng
2026-09-08 16:18 ` Leo Yan
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