linux/kernel/dma
Robin Murphy 4a37f3dd9a dma-direct: don't over-decrypt memory
The original x86 sev_alloc() only called set_memory_decrypted() on
memory returned by alloc_pages_node(), so the page order calculation
fell out of that logic. However, the common dma-direct code has several
potential allocators, not all of which are guaranteed to round up the
underlying allocation to a power-of-two size, so carrying over that
calculation for the encryption/decryption size was a mistake. Fix it by
rounding to a *number* of pages, rather than an order.

Until recently there was an even worse interaction with DMA_DIRECT_REMAP
where we could have ended up decrypting part of the next adjacent
vmalloc area, only averted by no architecture actually supporting both
configs at once. Don't ask how I found that one out...

Fixes: c10f07aa27 ("dma/direct: Handle force decryption for DMA coherent buffers in common code")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Rientjes <rientjes@google.com>
2022-05-23 15:25:40 +02:00
..
coherent.c dma-mapping: use 'bitmap_zalloc()' when applicable 2021-10-27 08:20:09 +02:00
contiguous.c cma: factor out minimum alignment requirement 2022-03-22 15:57:05 -07:00
debug.c dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC 2022-05-11 19:48:34 +02:00
debug.h dma-debug: teach add_dma_entry() about DMA_ATTR_SKIP_CPU_SYNC 2021-10-18 12:46:45 +02:00
direct.c dma-direct: don't over-decrypt memory 2022-05-23 15:25:40 +02:00
direct.h dma-direct: use is_swiotlb_active in dma_direct_map_page 2022-04-18 07:21:08 +02:00
dummy.c dma-mapping: return error code from dma_dummy_map_sg() 2021-08-09 17:13:06 +02:00
Kconfig dma-mapping: remove CONFIG_DMA_REMAP 2022-03-03 14:00:57 +03:00
Makefile dma-mapping: remove CONFIG_DMA_REMAP 2022-03-03 14:00:57 +03:00
map_benchmark.c dma-mapping: benchmark: extract a common header file for map_benchmark definition 2022-03-10 07:41:14 +01:00
mapping.c dma-mapping: move pgprot_decrypted out of dma_pgprot 2022-04-01 06:46:51 +02:00
ops_helpers.c dma-mapping: handle vmalloc addresses in dma_common_{mmap,get_sgtable} 2021-07-16 11:30:26 +02:00
pool.c dma/pool: create dma atomic pool only if dma zone has managed pages 2022-01-15 16:30:29 +02:00
remap.c kernel/dma: remove unnecessary unmap_kernel_range 2021-04-30 11:20:40 -07:00
swiotlb.c swiotlb: max mapping size takes min align mask into account 2022-05-17 11:21:52 +02:00