• Marek Szyprowski's avatar
    arm64: dma-mapping: always clear allocated buffers · 6829e274
    Marek Szyprowski authored
    
    
    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.
    
    Cc: <stable@vger.kernel.org> # v3.14+
    Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
    6829e274
dma-mapping.c 11.3 KB