[PATCH v2] arm64: dma-mapping: Fix dma_mapping_error() when bypassing SWIOTLB

Aaro Koskinen aaro.koskinen at iki.fi
Thu Jan 26 12:35:37 PST 2017


On Thu, Jan 26, 2017 at 03:20:47PM +0000, Robin Murphy wrote:
> hell, and having had a closer look I found another sweet nugget - if
> someone calls dma_alloc_coherent() in non-blocking context, for a
> sufficiently large order that the initial __get_free_pages() call from
> swiotlb_alloc_coherent() fails (hey, small-memory systems *are* going to
> suffer fragmentation), then we'll end up poking around in yet more
> uninitialised internals trying to allocate out of the non-existent
> bounce buffer.

I think this shouldn't happen anymore after 524dabe1c68e ("arm64: Fix
swiotlb fallback allocation").


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