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" <dwlsalmeida@xxxxxxxxx> > > > > 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 <dwlsalmeida@xxxxxxxxx> > > --- > > 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
