* [PATCH 1/3] media: imx: Unregister csc/scaler only if registered
@ 2020-12-28 12:21 Ezequiel Garcia
2020-12-28 12:21 ` [PATCH 2/3] media: imx: Fix csc/scaler unregister Ezequiel Garcia
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: Ezequiel Garcia @ 2020-12-28 12:21 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>
---
drivers/staging/media/imx/imx-media-dev.c | 6 +++++-
1 file changed, 5 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..b6d5f844ad79 100644
--- a/drivers/staging/media/imx/imx-media-dev.c
+++ b/drivers/staging/media/imx/imx-media-dev.c
@@ -107,10 +107,14 @@ 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] 7+ messages in thread
* [PATCH 2/3] media: imx: Fix csc/scaler unregister
2020-12-28 12:21 [PATCH 1/3] media: imx: Unregister csc/scaler only if registered Ezequiel Garcia
@ 2020-12-28 12:21 ` Ezequiel Garcia
2021-01-04 17:27 ` Philipp Zabel
2020-12-28 12:21 ` [PATCH 3/3] media: imx: Clean capture unregister Ezequiel Garcia
2021-01-04 17:16 ` [PATCH 1/3] media: imx: Unregister csc/scaler only if registered Philipp Zabel
2 siblings, 1 reply; 7+ messages in thread
From: Ezequiel Garcia @ 2020-12-28 12:21 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>
---
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] 7+ messages in thread
* [PATCH 3/3] media: imx: Clean capture unregister
2020-12-28 12:21 [PATCH 1/3] media: imx: Unregister csc/scaler only if registered Ezequiel Garcia
2020-12-28 12:21 ` [PATCH 2/3] media: imx: Fix csc/scaler unregister Ezequiel Garcia
@ 2020-12-28 12:21 ` Ezequiel Garcia
2021-01-04 17:29 ` Philipp Zabel
2021-01-04 17:16 ` [PATCH 1/3] media: imx: Unregister csc/scaler only if registered Philipp Zabel
2 siblings, 1 reply; 7+ messages in thread
From: Ezequiel Garcia @ 2020-12-28 12:21 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.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
---
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] 7+ messages in thread
* Re: [PATCH 1/3] media: imx: Unregister csc/scaler only if registered
2020-12-28 12:21 [PATCH 1/3] media: imx: Unregister csc/scaler only if registered Ezequiel Garcia
2020-12-28 12:21 ` [PATCH 2/3] media: imx: Fix csc/scaler unregister Ezequiel Garcia
2020-12-28 12:21 ` [PATCH 3/3] media: imx: Clean capture unregister Ezequiel Garcia
@ 2021-01-04 17:16 ` Philipp Zabel
2021-01-04 20:19 ` Ezequiel Garcia
2 siblings, 1 reply; 7+ messages in thread
From: Philipp Zabel @ 2021-01-04 17:16 UTC (permalink / raw)
To: Ezequiel Garcia, linux-media, Hans Verkuil
Cc: kernel, Laurent Pinchart, Steve Longerbeam, NXP Linux Team
Hi Ezequiel,
On Mon, 2020-12-28 at 09:21 -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>
> ---
> drivers/staging/media/imx/imx-media-dev.c | 6 +++++-
> 1 file changed, 5 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..b6d5f844ad79 100644
> --- a/drivers/staging/media/imx/imx-media-dev.c
> +++ b/drivers/staging/media/imx/imx-media-dev.c
> @@ -107,10 +107,14 @@ static int imx_media_remove(struct platform_device *pdev)
>
> v4l2_info(&imxmd->v4l2_dev, "Removing imx-media\n");
>
> + if (imxmd->m2m_vdev) {
Thank you, it's even worse. If imx_media_csc_scaler_device_init() fails
in imx6_media_probe_complete(), imxmd->m2m_vdev contains an error value.
So either this should check
if (!IS_ERR_OR_NULL(imxmd->m2m_vdev))
or (probably better) probe_complete should be changed as well.
> + 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);
regards
Philipp
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 2/3] media: imx: Fix csc/scaler unregister
2020-12-28 12:21 ` [PATCH 2/3] media: imx: Fix csc/scaler unregister Ezequiel Garcia
@ 2021-01-04 17:27 ` Philipp Zabel
0 siblings, 0 replies; 7+ messages in thread
From: Philipp Zabel @ 2021-01-04 17:27 UTC (permalink / raw)
To: Ezequiel Garcia, linux-media, Hans Verkuil
Cc: kernel, Laurent Pinchart, Steve Longerbeam, NXP Linux Team
On Mon, 2020-12-28 at 09:21 -0300, Ezequiel Garcia wrote:
> 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>
> ---
> 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 *
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
regards
Philipp
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 3/3] media: imx: Clean capture unregister
2020-12-28 12:21 ` [PATCH 3/3] media: imx: Clean capture unregister Ezequiel Garcia
@ 2021-01-04 17:29 ` Philipp Zabel
0 siblings, 0 replies; 7+ messages in thread
From: Philipp Zabel @ 2021-01-04 17:29 UTC (permalink / raw)
To: Ezequiel Garcia, linux-media, Hans Verkuil
Cc: kernel, Laurent Pinchart, Steve Longerbeam, NXP Linux Team
On Mon, 2020-12-28 at 09:21 -0300, Ezequiel Garcia wrote:
> No locking is needed to call video_unregister_device(). Drop it.
The commit message should probably also mention that the superfluous
video_is_registered() check is dropped and media_entity_cleanup() and
video_unregister_device() are reordered.
> Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> ---
> 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);
regards
Philipp
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/3] media: imx: Unregister csc/scaler only if registered
2021-01-04 17:16 ` [PATCH 1/3] media: imx: Unregister csc/scaler only if registered Philipp Zabel
@ 2021-01-04 20:19 ` Ezequiel Garcia
0 siblings, 0 replies; 7+ messages in thread
From: Ezequiel Garcia @ 2021-01-04 20:19 UTC (permalink / raw)
To: Philipp Zabel, linux-media, Hans Verkuil
Cc: kernel, Laurent Pinchart, Steve Longerbeam, NXP Linux Team
Hello Philipp,
Thanks for the quick review.
On Mon, 2021-01-04 at 18:16 +0100, Philipp Zabel wrote:
> Hi Ezequiel,
>
> On Mon, 2020-12-28 at 09:21 -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>
> > ---
> > drivers/staging/media/imx/imx-media-dev.c | 6 +++++-
> > 1 file changed, 5 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..b6d5f844ad79 100644
> > --- a/drivers/staging/media/imx/imx-media-dev.c
> > +++ b/drivers/staging/media/imx/imx-media-dev.c
> > @@ -107,10 +107,14 @@ static int imx_media_remove(struct platform_device *pdev)
> >
> > v4l2_info(&imxmd->v4l2_dev, "Removing imx-media\n");
> >
> > + if (imxmd->m2m_vdev) {
>
> Thank you, it's even worse. If imx_media_csc_scaler_device_init() fails
> in imx6_media_probe_complete(), imxmd->m2m_vdev contains an error value.
>
> So either this should check
>
> if (!IS_ERR_OR_NULL(imxmd->m2m_vdev))
>
> or (probably better) probe_complete should be changed as well.
>
Good catch. I guess the simplest solution for that is to
clear the m2m_vdev pointer in imx6_media_probe_complete,
if it fails.
Thanks,
Ezequiel
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2021-01-04 20:20 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-12-28 12:21 [PATCH 1/3] media: imx: Unregister csc/scaler only if registered Ezequiel Garcia
2020-12-28 12:21 ` [PATCH 2/3] media: imx: Fix csc/scaler unregister Ezequiel Garcia
2021-01-04 17:27 ` Philipp Zabel
2020-12-28 12:21 ` [PATCH 3/3] media: imx: Clean capture unregister Ezequiel Garcia
2021-01-04 17:29 ` Philipp Zabel
2021-01-04 17:16 ` [PATCH 1/3] media: imx: Unregister csc/scaler only if registered Philipp Zabel
2021-01-04 20:19 ` Ezequiel Garcia
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