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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-19 18:39:47 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-19 18:39:47 +0300 |
commit | 63ae602cea637ee4a6490d940c0da5d78bd0bbe0 (patch) | |
tree | 5da1eec3756fec9d62455c498442944a7f35149b /drivers/media/v4l2-core | |
parent | 1a1891d762d6e64daf07b5be4817e3fbb29e3c59 (diff) | |
parent | f307ab6dcea03f9d8e4d70508fd7d1ca57cfa7f9 (diff) | |
download | linux-63ae602cea637ee4a6490d940c0da5d78bd0bbe0.tar.xz |
Merge branch 'gup_flag-cleanups'
Merge the gup_flags cleanups from Lorenzo Stoakes:
"This patch series adjusts functions in the get_user_pages* family such
that desired FOLL_* flags are passed as an argument rather than
implied by flags.
The purpose of this change is to make the use of FOLL_FORCE explicit
so it is easier to grep for and clearer to callers that this flag is
being used. The use of FOLL_FORCE is an issue as it overrides missing
VM_READ/VM_WRITE flags for the VMA whose pages we are reading
from/writing to, which can result in surprising behaviour.
The patch series came out of the discussion around commit 38e088546522
("mm: check VMA flags to avoid invalid PROT_NONE NUMA balancing"),
which addressed a BUG_ON() being triggered when a page was faulted in
with PROT_NONE set but having been overridden by FOLL_FORCE.
do_numa_page() was run on the assumption the page _must_ be one marked
for NUMA node migration as an actual PROT_NONE page would have been
dealt with prior to this code path, however FOLL_FORCE introduced a
situation where this assumption did not hold.
See
https://marc.info/?l=linux-mm&m=147585445805166
for the patch proposal"
Additionally, there's a fix for an ancient bug related to FOLL_FORCE and
FOLL_WRITE by me.
[ This branch was rebased recently to add a few more acked-by's and
reviewed-by's ]
* gup_flag-cleanups:
mm: replace access_process_vm() write parameter with gup_flags
mm: replace access_remote_vm() write parameter with gup_flags
mm: replace __access_remote_vm() write parameter with gup_flags
mm: replace get_user_pages_remote() write/force parameters with gup_flags
mm: replace get_user_pages() write/force parameters with gup_flags
mm: replace get_vaddr_frames() write/force parameters with gup_flags
mm: replace get_user_pages_locked() write/force parameters with gup_flags
mm: replace get_user_pages_unlocked() write/force parameters with gup_flags
mm: remove write/force parameters from __get_user_pages_unlocked()
mm: remove write/force parameters from __get_user_pages_locked()
mm: remove gup_flags FOLL_WRITE games from __get_user_pages()
Diffstat (limited to 'drivers/media/v4l2-core')
-rw-r--r-- | drivers/media/v4l2-core/videobuf-dma-sg.c | 7 | ||||
-rw-r--r-- | drivers/media/v4l2-core/videobuf2-memops.c | 6 |
2 files changed, 10 insertions, 3 deletions
diff --git a/drivers/media/v4l2-core/videobuf-dma-sg.c b/drivers/media/v4l2-core/videobuf-dma-sg.c index f300f060b3f3..1db0af6c7f94 100644 --- a/drivers/media/v4l2-core/videobuf-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf-dma-sg.c @@ -156,6 +156,7 @@ static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma, { unsigned long first, last; int err, rw = 0; + unsigned int flags = FOLL_FORCE; dma->direction = direction; switch (dma->direction) { @@ -178,12 +179,14 @@ static int videobuf_dma_init_user_locked(struct videobuf_dmabuf *dma, if (NULL == dma->pages) return -ENOMEM; + if (rw == READ) + flags |= FOLL_WRITE; + dprintk(1, "init user [0x%lx+0x%lx => %d pages]\n", data, size, dma->nr_pages); err = get_user_pages(data & PAGE_MASK, dma->nr_pages, - rw == READ, 1, /* force */ - dma->pages, NULL); + flags, dma->pages, NULL); if (err != dma->nr_pages) { dma->nr_pages = (err >= 0) ? err : 0; diff --git a/drivers/media/v4l2-core/videobuf2-memops.c b/drivers/media/v4l2-core/videobuf2-memops.c index 3c3b517f1d1c..1cd322e939c7 100644 --- a/drivers/media/v4l2-core/videobuf2-memops.c +++ b/drivers/media/v4l2-core/videobuf2-memops.c @@ -42,6 +42,10 @@ struct frame_vector *vb2_create_framevec(unsigned long start, unsigned long first, last; unsigned long nr; struct frame_vector *vec; + unsigned int flags = FOLL_FORCE; + + if (write) + flags |= FOLL_WRITE; first = start >> PAGE_SHIFT; last = (start + length - 1) >> PAGE_SHIFT; @@ -49,7 +53,7 @@ struct frame_vector *vb2_create_framevec(unsigned long start, vec = frame_vector_create(nr); if (!vec) return ERR_PTR(-ENOMEM); - ret = get_vaddr_frames(start & PAGE_MASK, nr, write, true, vec); + ret = get_vaddr_frames(start & PAGE_MASK, nr, flags, vec); if (ret < 0) goto out_destroy; /* We accept only complete set of PFNs */ |