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| author | Marek Szyprowski <m.szyprowski@samsung.com> | 2012-06-12 15:18:16 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-11-25 20:21:32 +0100 |
| commit | d81e870d5afa1b0a95ea94c4052d3c7e973fae8c (patch) | |
| tree | fbf9102a76c986ca9b6527570d160c905e3f9e7c /drivers/media | |
| parent | [media] v4l: vb2-dma-contig: add reference counting for a device from allocat... (diff) | |
| download | linux-d81e870d5afa1b0a95ea94c4052d3c7e973fae8c.tar.xz linux-d81e870d5afa1b0a95ea94c4052d3c7e973fae8c.zip | |
[media] v4l: vb2-dma-contig: fail if user ptr buffer is not correctly aligned
The DMA transfer must be aligned to a specific value. If userptr is not aligned
to DMA requirements then unexpected corruptions of the memory may occur before
or after a buffer. To prevent such situations, all unligned userptr buffers
are rejected at VIDIOC_QBUF.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-dma-contig.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index b35f38e9f2d7..27de1bb731db 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -491,6 +491,18 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr, struct vm_area_struct *vma; struct sg_table *sgt; unsigned long contig_size; + unsigned long dma_align = dma_get_cache_alignment(); + + /* Only cache aligned DMA transfers are reliable */ + if (!IS_ALIGNED(vaddr | size, dma_align)) { + pr_debug("user data must be aligned to %lu bytes\n", dma_align); + return ERR_PTR(-EINVAL); + } + + if (!size) { + pr_debug("size is zero\n"); + return ERR_PTR(-EINVAL); + } buf = kzalloc(sizeof *buf, GFP_KERNEL); if (!buf) |