On Tue, Mar 12, 2019 at 05:16:37PM +0800, Yue Haibing wrote: > From: YueHaibing <[email protected]> > > Like commit 518a2f1925c3 ("dma-mapping: zero memory returned > from dma_alloc_*"), if we want to map memory from the DMA > allocator to userspace it must be zeroed at allocation time > to prevent stale data leaks. On arm platform, if the allocator > is pool_allocator in __dma_alloc, then the mem is alloced by > __alloc_from_pool, which also need be zeroed.
The observations looks correct, and because this memory is already remapped I don't think we need __dma_clear_buffer here. But I'd love to see a review from Russell as well.
