On 11/02/2013 02:31 PM, Mauro Carvalho Chehab wrote: > Dynamic static allocation is evil, as Kernel stack is too low, and > compilation complains about it on some archs: > > drivers/media/v4l2-core/v4l2-async.c:238:1: warning: 'v4l2_async_notifier_unregister' uses dynamic stack allocation [enabled by default] > > Instead, let's enforce a limit for the buffer. > > In this specific case, there's a hard limit imposed by V4L2_MAX_SUBDEVS, > with is currently 128. That means that the buffer size can be up to > 128x8 = 1024 bytes (on a 64bits kernel), with is too big for stack. > > Worse than that, someone could increase it and cause real troubles. > > So, let's use dynamically allocated data, instead. > > Signed-off-by: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx> > Cc: Guennadi Liakhovetski <g.liakhovetski@xxxxxx> > --- > drivers/media/v4l2-core/v4l2-async.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c > index c85d69da35bd..071596869036 100644 > --- a/drivers/media/v4l2-core/v4l2-async.c > +++ b/drivers/media/v4l2-core/v4l2-async.c > @@ -189,12 +189,14 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier) > struct v4l2_subdev *sd, *tmp; > unsigned int notif_n_subdev = notifier->num_subdevs; > unsigned int n_subdev = min(notif_n_subdev, V4L2_MAX_SUBDEVS); > - struct device *dev[n_subdev]; > + struct device **dev; > int i = 0; > > if (!notifier->v4l2_dev) > return; > > + dev = kmalloc(sizeof(*dev) * n_subdev, GFP_KERNEL); > + No check for dev == NULL? Regards, Hans > mutex_lock(&list_lock); > > list_del(¬ifier->list); > @@ -228,6 +230,7 @@ void v4l2_async_notifier_unregister(struct v4l2_async_notifier *notifier) > } > put_device(d); > } > + kfree(dev); > > notifier->v4l2_dev = NULL; > > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
