Commit 735de5ca authored by Hans Verkuil's avatar Hans Verkuil
Browse files

media: vb2: frame_vector.c: replace WARN_ONCE with a comment 



The WARN_ONCE was issued also in cases that had nothing to do with VM_IO
(e.g. if the start address was just a random value and uaccess fails with
-EFAULT).

There are no reports of WARN_ONCE being issued for actual VM_IO cases, so
just drop it and instead add a note to the comment before the function.

Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Reported-by: default avatarYikebaer Aizezi <yikebaer61@gmail.com>
parent 41ebaa5e

drivers/media/common/videobuf2/frame_vector.c

+4 −2
Original line number Diff line number Diff line
@@ -31,6 +31,10 @@ 
 * different type underlying the specified range of virtual addresses.

 * When the function isn't able to map a single page, it returns error.

 *

 * Note that get_vaddr_frames() cannot follow VM_IO mappings. It used

 * to be able to do that, but that could (racily) return non-refcounted

 * pfns.

 *

 * This function takes care of grabbing mmap_lock as necessary.

 */

int get_vaddr_frames(unsigned long start, unsigned int nr_frames, bool write,
@@ -59,8 +63,6 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, bool write, 
	if (likely(ret > 0))

		return ret;



	/* This used to (racily) return non-refcounted pfns. Let people know */

	WARN_ONCE(1, "get_vaddr_frames() cannot follow VM_IO mapping");

	vec->nr_frames = 0;

	return ret ? ret : -EFAULT;

}