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Commit 9df97414 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Alistair Delva
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UPSTREAM: media/v4l2-core: untag user pointers in videobuf_dma_contig_user_get 

(Upstream commit e275faf367e3a3b9db06a71924b199f429d3d508).

This patch is a part of a series that extends kernel ABI to allow to pass
tagged user pointers (with the top byte set to something else other than
0x00) as syscall arguments.

videobuf_dma_contig_user_get() uses provided user pointers for vma
lookups, which can only by done with untagged pointers.

Untag the pointers in this function.

Link: http://lkml.kernel.org/r/100436d5f8e4349a78f27b0bbb27e4801fcb946b.1563904656.git.andreyknvl@google.com


Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Reviewed-by: default avatarKhalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Bug: 135692346
Change-Id: I23682c456e3dd8d87df536bc60fd4253d9403c28
parent d224d76f

drivers/media/v4l2-core/videobuf-dma-contig.c

+5 −4
Original line number Diff line number Diff line
@@ -160,6 +160,7 @@ static void videobuf_dma_contig_user_put(struct videobuf_dma_contig_memory *mem) 
static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem,

					struct videobuf_buffer *vb)

{

	unsigned long untagged_baddr = untagged_addr(vb->baddr);

	struct mm_struct *mm = current->mm;

	struct vm_area_struct *vma;

	unsigned long prev_pfn, this_pfn;
@@ -167,22 +168,22 @@ static int videobuf_dma_contig_user_get(struct videobuf_dma_contig_memory *mem, 
	unsigned int offset;

	int ret;



	offset = vb->baddr & ~PAGE_MASK;

	offset = untagged_baddr & ~PAGE_MASK;

	mem->size = PAGE_ALIGN(vb->size + offset);

	ret = -EINVAL;



	down_read(&mm->mmap_sem);



	vma = find_vma(mm, vb->baddr);

	vma = find_vma(mm, untagged_baddr);

	if (!vma)

		goto out_up;



	if ((vb->baddr + mem->size) > vma->vm_end)

	if ((untagged_baddr + mem->size) > vma->vm_end)

		goto out_up;



	pages_done = 0;

	prev_pfn = 0; /* kill warning */

	user_address = vb->baddr;

	user_address = untagged_baddr;



	while (pages_done < (mem->size >> PAGE_SHIFT)) {

		ret = follow_pfn(vma, user_address, &this_pfn);