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mm/frame-vector: remove FOLL_FORCE usage

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FOLL_FORCE is really only for ptrace access. According to commit
707947247e ("media: videobuf2-vmalloc: get_userptr: buffers are always
writable"), get_vaddr_frames() currently pins all pages writable as a
workaround for issues with read-only buffers.

FOLL_FORCE, however, seems to be a legacy leftover as it predates
commit 707947247e ("media: videobuf2-vmalloc: get_userptr: buffers are
always writable"). Let's just remove it.

Once the read-only buffer issue has been resolved, FOLL_WRITE could
again be set depending on the DMA direction.

Link: https://lkml.kernel.org/r/20221116102659.70287-17-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Acked-by: Tomasz Figa <tfiga@chromium.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
David Hildenbrand 2022-11-16 11:26:55 +01:00 committed by Andrew Morton
parent 70b96f24a4
commit cb78a634f3
1 changed files with 1 additions and 1 deletions
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2
drivers/media/common/videobuf2/frame_vector.c
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@ -50,7 +50,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
start = untagged_addr(start);
ret = pin_user_pages_fast(start, nr_frames,
FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM,
FOLL_WRITE | FOLL_LONGTERM,
(struct page **)(vec->ptrs));
if (ret > 0) {
vec->got_ref = true;