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V4L/DVB (13598): videobuf_dma_contig_user_get() for non-aligned offsets

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If a USERPTR address that is not aligned to page boundary is passed to the
videobuf_dma_contig_user_get() function, it saves a page aligned address to
the dma_handle. This is not correct. This issue is observed when using USERPTR
IO machism for buffer exchange.

Updates from last version:-

Adding offset for size calculation as per comment from Magnus Damm. This
ensures the last page is also included for checking if memory is
contiguous.

Signed-off-by: Muralidharan Karicheri <m-karicheri2@ti.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Muralidharan Karicheri 2009-12-10 16:47:48 -03:00 committed by Mauro Carvalho Chehab
parent 0d94e29459
commit 31bedfa506
1 changed files with 4 additions and 2 deletions
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6
drivers/media/video/videobuf-dma-contig.c
View file

@ -141,9 +141,11 @@ static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem,
struct vm_area_struct *vma;
unsigned long prev_pfn, this_pfn;
unsigned long pages_done, user_address;
unsigned int offset;
int ret;
mem->size = PAGE_ALIGN(vb->size);
offset = vb->baddr & ~PAGE_MASK;
mem->size = PAGE_ALIGN(vb->size + offset);
mem->is_userptr = 0;
ret = -EINVAL;
@ -166,7 +168,7 @@ static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem,
break;
if (pages_done == 0)
mem->dma_handle = this_pfn << PAGE_SHIFT;
mem->dma_handle = (this_pfn << PAGE_SHIFT) + offset;
else if (this_pfn != (prev_pfn + 1))
ret = -EFAULT;