* [PATCH v2 1/3] media: imx: Unregister csc/scaler only if registered
@ 2021-01-04 20:34 Ezequiel Garcia
2021-01-04 20:34 ` [PATCH v2 2/3] media: imx: Fix csc/scaler unregister Ezequiel Garcia
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Ezequiel Garcia @ 2021-01-04 20:34 UTC (permalink / raw)
To: linux-media, Hans Verkuil
Cc: kernel, Laurent Pinchart, Steve Longerbeam, Philipp Zabel,
NXP Linux Team, Ezequiel Garcia
The csc/scaler device pointer (imxmd->m2m_vdev) is assigned
after the imx media device v4l2-async probe completes,
therefore we need to check if the device is non-NULL
before trying to unregister it.
This can be the case if the non-completed imx media device
is unbinded (or the driver is removed), leading to a kernel oops.
Fixes: a8ef0488cc59 ("media: imx: add csc/scaler mem2mem device")
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
---
v2:
* As noted by Philipp, set m2m_vdev to NULL if the csc/scaler
registration fails.
---
drivers/staging/media/imx/imx-media-dev.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/media/imx/imx-media-dev.c b/drivers/staging/media/imx/imx-media-dev.c
index 6d2205461e56..338b8bd0bb07 100644
--- a/drivers/staging/media/imx/imx-media-dev.c
+++ b/drivers/staging/media/imx/imx-media-dev.c
@@ -53,6 +53,7 @@ static int imx6_media_probe_complete(struct v4l2_async_notifier *notifier)
imxmd->m2m_vdev = imx_media_csc_scaler_device_init(imxmd);
if (IS_ERR(imxmd->m2m_vdev)) {
ret = PTR_ERR(imxmd->m2m_vdev);
+ imxmd->m2m_vdev = NULL;
goto unlock;
}
@@ -107,10 +108,14 @@ static int imx_media_remove(struct platform_device *pdev)
v4l2_info(&imxmd->v4l2_dev, "Removing imx-media\n");
+ if (imxmd->m2m_vdev) {
+ imx_media_csc_scaler_device_unregister(imxmd->m2m_vdev);
+ imxmd->m2m_vdev = NULL;
+ }
+
v4l2_async_notifier_unregister(&imxmd->notifier);
imx_media_unregister_ipu_internal_subdevs(imxmd);
v4l2_async_notifier_cleanup(&imxmd->notifier);
- imx_media_csc_scaler_device_unregister(imxmd->m2m_vdev);
media_device_unregister(&imxmd->md);
v4l2_device_unregister(&imxmd->v4l2_dev);
media_device_cleanup(&imxmd->md);
--
2.29.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 2/3] media: imx: Fix csc/scaler unregister
2021-01-04 20:34 [PATCH v2 1/3] media: imx: Unregister csc/scaler only if registered Ezequiel Garcia
@ 2021-01-04 20:34 ` Ezequiel Garcia
2021-01-04 20:34 ` [PATCH v2 3/3] media: imx: Clean capture unregister Ezequiel Garcia
2021-01-05 9:33 ` [PATCH v2 1/3] media: imx: Unregister csc/scaler only if registered Philipp Zabel
2 siblings, 0 replies; 5+ messages in thread
From: Ezequiel Garcia @ 2021-01-04 20:34 UTC (permalink / raw)
To: linux-media, Hans Verkuil
Cc: kernel, Laurent Pinchart, Steve Longerbeam, Philipp Zabel,
NXP Linux Team, Ezequiel Garcia
The csc/scaler device private struct is released by
ipu_csc_scaler_video_device_release(), which can be called
by video_unregister_device() if there are no users
of the underlying struct video device.
Therefore, the mutex can't be held when calling
video_unregister_device() as its memory may be freed
by it, leading to a kernel oops.
Fortunately, the fix is quite simple as no locking
is needed when calling video_unregister_device(): v4l2-core
already has its own internal locking, and the structures
are also properly refcounted.
Fixes: a8ef0488cc59 ("media: imx: add csc/scaler mem2mem device")
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
---
drivers/staging/media/imx/imx-media-csc-scaler.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/drivers/staging/media/imx/imx-media-csc-scaler.c b/drivers/staging/media/imx/imx-media-csc-scaler.c
index fab1155a5958..63a0204502a8 100644
--- a/drivers/staging/media/imx/imx-media-csc-scaler.c
+++ b/drivers/staging/media/imx/imx-media-csc-scaler.c
@@ -869,11 +869,7 @@ void imx_media_csc_scaler_device_unregister(struct imx_media_video_dev *vdev)
struct ipu_csc_scaler_priv *priv = vdev_to_priv(vdev);
struct video_device *vfd = priv->vdev.vfd;
- mutex_lock(&priv->mutex);
-
video_unregister_device(vfd);
-
- mutex_unlock(&priv->mutex);
}
struct imx_media_video_dev *
--
2.29.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 3/3] media: imx: Clean capture unregister
2021-01-04 20:34 [PATCH v2 1/3] media: imx: Unregister csc/scaler only if registered Ezequiel Garcia
2021-01-04 20:34 ` [PATCH v2 2/3] media: imx: Fix csc/scaler unregister Ezequiel Garcia
@ 2021-01-04 20:34 ` Ezequiel Garcia
2021-01-05 9:33 ` Philipp Zabel
2021-01-05 9:33 ` [PATCH v2 1/3] media: imx: Unregister csc/scaler only if registered Philipp Zabel
2 siblings, 1 reply; 5+ messages in thread
From: Ezequiel Garcia @ 2021-01-04 20:34 UTC (permalink / raw)
To: linux-media, Hans Verkuil
Cc: kernel, Laurent Pinchart, Steve Longerbeam, Philipp Zabel,
NXP Linux Team, Ezequiel Garcia
No locking is needed to call video_unregister_device(). Drop it.
Also, drop the superfluous video_is_registered() call, which is
done by video_unregister_device(), and re-order media_entity_cleanup()
and video_unregister_device() calls.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
---
v2:
* As suggested by Philipp, write a more complete commit description.
---
drivers/staging/media/imx/imx-media-capture.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/drivers/staging/media/imx/imx-media-capture.c b/drivers/staging/media/imx/imx-media-capture.c
index c1931eb2540e..e10ce103a5b4 100644
--- a/drivers/staging/media/imx/imx-media-capture.c
+++ b/drivers/staging/media/imx/imx-media-capture.c
@@ -816,14 +816,8 @@ void imx_media_capture_device_unregister(struct imx_media_video_dev *vdev)
struct capture_priv *priv = to_capture_priv(vdev);
struct video_device *vfd = priv->vdev.vfd;
- mutex_lock(&priv->mutex);
-
- if (video_is_registered(vfd)) {
- video_unregister_device(vfd);
- media_entity_cleanup(&vfd->entity);
- }
-
- mutex_unlock(&priv->mutex);
+ media_entity_cleanup(&vfd->entity);
+ video_unregister_device(vfd);
}
EXPORT_SYMBOL_GPL(imx_media_capture_device_unregister);
--
2.29.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2 1/3] media: imx: Unregister csc/scaler only if registered
2021-01-04 20:34 [PATCH v2 1/3] media: imx: Unregister csc/scaler only if registered Ezequiel Garcia
2021-01-04 20:34 ` [PATCH v2 2/3] media: imx: Fix csc/scaler unregister Ezequiel Garcia
2021-01-04 20:34 ` [PATCH v2 3/3] media: imx: Clean capture unregister Ezequiel Garcia
@ 2021-01-05 9:33 ` Philipp Zabel
2 siblings, 0 replies; 5+ messages in thread
From: Philipp Zabel @ 2021-01-05 9:33 UTC (permalink / raw)
To: Ezequiel Garcia, linux-media, Hans Verkuil
Cc: kernel, Laurent Pinchart, Steve Longerbeam, NXP Linux Team
On Mon, 2021-01-04 at 17:34 -0300, Ezequiel Garcia wrote:
> The csc/scaler device pointer (imxmd->m2m_vdev) is assigned
> after the imx media device v4l2-async probe completes,
> therefore we need to check if the device is non-NULL
> before trying to unregister it.
>
> This can be the case if the non-completed imx media device
> is unbinded (or the driver is removed), leading to a kernel oops.
>
> Fixes: a8ef0488cc59 ("media: imx: add csc/scaler mem2mem device")
> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
regards
Philipp
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 3/3] media: imx: Clean capture unregister
2021-01-04 20:34 ` [PATCH v2 3/3] media: imx: Clean capture unregister Ezequiel Garcia
@ 2021-01-05 9:33 ` Philipp Zabel
0 siblings, 0 replies; 5+ messages in thread
From: Philipp Zabel @ 2021-01-05 9:33 UTC (permalink / raw)
To: Ezequiel Garcia, linux-media, Hans Verkuil
Cc: kernel, Laurent Pinchart, Steve Longerbeam, NXP Linux Team
On Mon, 2021-01-04 at 17:34 -0300, Ezequiel Garcia wrote:
> No locking is needed to call video_unregister_device(). Drop it.
>
> Also, drop the superfluous video_is_registered() call, which is
> done by video_unregister_device(), and re-order media_entity_cleanup()
> and video_unregister_device() calls.
>
> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
regards
Philipp
^ permalink raw reply [flat|nested] 5+ messages in thread
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2021-01-04 20:34 [PATCH v2 1/3] media: imx: Unregister csc/scaler only if registered Ezequiel Garcia
2021-01-04 20:34 ` [PATCH v2 2/3] media: imx: Fix csc/scaler unregister Ezequiel Garcia
2021-01-04 20:34 ` [PATCH v2 3/3] media: imx: Clean capture unregister Ezequiel Garcia
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2021-01-05 9:33 ` [PATCH v2 1/3] media: imx: Unregister csc/scaler only if registered Philipp Zabel
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