From: "Daniel W. S. Almeida" <[email protected]>
Fixes the following coccinelle report:
drivers/media/usb/uvc/uvc_ctrl.c:1860:5-11:
ERROR: invalid reference to the index variable of the iterator on line 1854
By introducing a temporary variable to iterate the list.
Do not dereference the 'entity' pointer if it is not found in the list.
Found using - Coccinelle (http://coccinelle.lip6.fr)
Signed-off-by: Daniel W. S. Almeida <[email protected]>
---
drivers/media/usb/uvc/uvc_ctrl.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index e399b9fad757..567bdedc2ff2 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1842,7 +1842,8 @@ static int uvc_ctrl_init_xu_ctrl(struct uvc_device *dev,
int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
struct uvc_xu_control_query *xqry)
{
- struct uvc_entity *entity;
+ struct uvc_entity *entity = NULL;
+ struct uvc_entity *cursor = NULL;
struct uvc_control *ctrl;
unsigned int i, found = 0;
u32 reqflags;
@@ -1851,13 +1852,15 @@ int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
int ret;
/* Find the extension unit. */
- list_for_each_entry(entity, &chain->entities, chain) {
- if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT &&
- entity->id == xqry->unit)
+ list_for_each_entry(cursor, &chain->entities, chain) {
+ if (UVC_ENTITY_TYPE(cursor) == UVC_VC_EXTENSION_UNIT &&
+ cursor->id == xqry->unit) {
+ entity = cursor;
break;
+ }
}
- if (entity->id != xqry->unit) {
+ if (!entity || entity->id != xqry->unit) {
uvc_trace(UVC_TRACE_CONTROL, "Extension unit %u not found.\n",
xqry->unit);
return -ENOENT;
--
2.28.0
Hi Daniel,
Thank you for the patch.
On Fri, Aug 07, 2020 at 05:35:30AM -0300, Daniel W. S. Almeida wrote:
> From: "Daniel W. S. Almeida" <[email protected]>
>
> Fixes the following coccinelle report:
>
> drivers/media/usb/uvc/uvc_ctrl.c:1860:5-11:
> ERROR: invalid reference to the index variable of the iterator on line 1854
>
> By introducing a temporary variable to iterate the list.
>
> Do not dereference the 'entity' pointer if it is not found in the list.
>
> Found using - Coccinelle (http://coccinelle.lip6.fr)
>
> Signed-off-by: Daniel W. S. Almeida <[email protected]>
> ---
> drivers/media/usb/uvc/uvc_ctrl.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index e399b9fad757..567bdedc2ff2 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -1842,7 +1842,8 @@ static int uvc_ctrl_init_xu_ctrl(struct uvc_device *dev,
> int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
> struct uvc_xu_control_query *xqry)
> {
> - struct uvc_entity *entity;
> + struct uvc_entity *entity = NULL;
> + struct uvc_entity *cursor = NULL;
cursor doesn't have to be initialized to NULL.
It may be a style preference, but instead of a cursor variable that
doesn't tell in its name what it refers to, I'd prefer a
bool found = false;
> struct uvc_control *ctrl;
> unsigned int i, found = 0;
> u32 reqflags;
> @@ -1851,13 +1852,15 @@ int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
> int ret;
>
> /* Find the extension unit. */
> - list_for_each_entry(entity, &chain->entities, chain) {
> - if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT &&
> - entity->id == xqry->unit)
> + list_for_each_entry(cursor, &chain->entities, chain) {
> + if (UVC_ENTITY_TYPE(cursor) == UVC_VC_EXTENSION_UNIT &&
> + cursor->id == xqry->unit) {
All this would keep using entity.
> + entity = cursor;
And this would be replaced with
found = true;
> break;
> + }
> }
>
> - if (entity->id != xqry->unit) {
> + if (!entity || entity->id != xqry->unit) {
The second part of the check isn't needed, it was only meant to check if
the entity has been found.
Here, we'd have
if (!found) {
I'f you're OK with these changes there's no need to resubmit, I can
update when applying. Please let me know how you'd like to proceed.
> uvc_trace(UVC_TRACE_CONTROL, "Extension unit %u not found.\n",
> xqry->unit);
> return -ENOENT;
--
Regards,
Laurent Pinchart
Hi Daniel,
On Sat, Aug 08, 2020 at 11:40:13PM +0300, Laurent Pinchart wrote:
> On Fri, Aug 07, 2020 at 05:35:30AM -0300, Daniel W. S. Almeida wrote:
> > From: "Daniel W. S. Almeida" <[email protected]>
> >
> > Fixes the following coccinelle report:
> >
> > drivers/media/usb/uvc/uvc_ctrl.c:1860:5-11:
> > ERROR: invalid reference to the index variable of the iterator on line 1854
> >
> > By introducing a temporary variable to iterate the list.
> >
> > Do not dereference the 'entity' pointer if it is not found in the list.
> >
> > Found using - Coccinelle (http://coccinelle.lip6.fr)
> >
> > Signed-off-by: Daniel W. S. Almeida <[email protected]>
> > ---
> > drivers/media/usb/uvc/uvc_ctrl.c | 13 ++++++++-----
> > 1 file changed, 8 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> > index e399b9fad757..567bdedc2ff2 100644
> > --- a/drivers/media/usb/uvc/uvc_ctrl.c
> > +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> > @@ -1842,7 +1842,8 @@ static int uvc_ctrl_init_xu_ctrl(struct uvc_device *dev,
> > int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
> > struct uvc_xu_control_query *xqry)
> > {
> > - struct uvc_entity *entity;
> > + struct uvc_entity *entity = NULL;
> > + struct uvc_entity *cursor = NULL;
>
> cursor doesn't have to be initialized to NULL.
>
> It may be a style preference, but instead of a cursor variable that
> doesn't tell in its name what it refers to, I'd prefer a
>
> bool found = false;
>
> > struct uvc_control *ctrl;
> > unsigned int i, found = 0;
> > u32 reqflags;
> > @@ -1851,13 +1852,15 @@ int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
> > int ret;
> >
> > /* Find the extension unit. */
> > - list_for_each_entry(entity, &chain->entities, chain) {
> > - if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT &&
> > - entity->id == xqry->unit)
> > + list_for_each_entry(cursor, &chain->entities, chain) {
> > + if (UVC_ENTITY_TYPE(cursor) == UVC_VC_EXTENSION_UNIT &&
> > + cursor->id == xqry->unit) {
>
> All this would keep using entity.
>
> > + entity = cursor;
>
> And this would be replaced with
>
> found = true;
>
> > break;
> > + }
I forgot to mention that the indentation is incorrect here.
> > }
> >
> > - if (entity->id != xqry->unit) {
> > + if (!entity || entity->id != xqry->unit) {
>
> The second part of the check isn't needed, it was only meant to check if
> the entity has been found.
>
> Here, we'd have
>
> if (!found) {
>
> I'f you're OK with these changes there's no need to resubmit, I can
> update when applying. Please let me know how you'd like to proceed.
>
> > uvc_trace(UVC_TRACE_CONTROL, "Extension unit %u not found.\n",
> > xqry->unit);
> > return -ENOENT;
--
Regards,
Laurent Pinchart
Hi Laurent!
> I'f you're OK with these changes there's no need to resubmit, I can
> update when applying. Please let me know how you'd like to proceed.
That's OK with me!
Thanks for reviewing.
- Daniel