arm64: dma-mapping: always clear allocated buffers

Browse source

commit 6829e274a6 upstream.

Buffers allocated by dma_alloc_coherent() are always zeroed on Alpha,
ARM (32bit), MIPS, PowerPC, x86/x86_64 and probably other architectures.
It turned out that some drivers rely on this 'feature'. Allocated buffer
might be also exposed to userspace with dma_mmap() call, so clearing it
is desired from security point of view to avoid exposing random memory
to userspace. This patch unifies dma_alloc_coherent() behavior on ARM64
architecture with other implementations by unconditionally zeroing
allocated buffer.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
[ luis: backported to 3.16:
  - dropped changes to __alloc_from_pool() which doesn't exist in 3.16 ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

...

This commit is contained in:

Marek Szyprowski 2015-04-23 12:46:16 +01:00 • committed by Luis Henriques

parent cf62a98393

commit a92a43a16c

1 changed files with 1 additions and 2 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

3

arch/arm64/mm/dma-mapping.c

View file