author | Marek Szyprowski <m.szyprowski@samsung.com> | |
Thu, 23 Apr 2015 11:46:16 +0000 (12:46 +0100) | ||
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
Sat, 4 Jul 2015 02:49:04 +0000 (19:49 -0700) | ||
commit | 22ff38e850b7fc87bdcccbebe92c3e7764ffe389 | |
tree | 2cd8d9e51395cb1565e315647842e0f966aa5185 | tree | snapshot (tar.xz tar.gz zip) |
parent | 762167f98c6aa8d47c801f8b6ac20bf30d786a4b | commit | diff |
arm64: dma-mapping: always clear allocated buffers
commit 6829e274a623187c24f7cfc0e3d35f25d087fcc5 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>
[will: ported to 3.14.y]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6829e274a623187c24f7cfc0e3d35f25d087fcc5 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>
[will: ported to 3.14.y]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/arm64/mm/dma-mapping.c | diff | blob | history |