On Fri 22-08-14 18:01:09, Hans Verkuil wrote: > Commit f035eb4e976ef5a059e30bc91cfd310ff030a7d3 (videobuf2: fix lockdep warning) > unfortunately removed the mmap_sem lock that is needed around the call to > __qbuf_userptr. Amazingly nobody noticed this until Jan Kara pointed this out > to me. > > Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > Reported-by: Jan Kara <jack@xxxxxxx> ... > @@ -1627,7 +1628,9 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b) > ret = __qbuf_mmap(vb, b); > break; > case V4L2_MEMORY_USERPTR: I guess you are missing something like: mmap_sem = ¤t->mm->mmap_sem; Honza > + down_read(mmap_sem); > ret = __qbuf_userptr(vb, b); > + up_read(mmap_sem); > break; > case V4L2_MEMORY_DMABUF: > ret = __qbuf_dmabuf(vb, b); > -- > 2.0.1 > -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- 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
