diff options
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/swiotlb.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 0ed0e1f215c7..274587a57717 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -597,9 +597,14 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, io_tlb_orig_addr[index + i] = slot_addr(orig_addr, i); tlb_addr = slot_addr(io_tlb_start, index) + offset; - if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && - (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) - swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE); + /* + * When dir == DMA_FROM_DEVICE we could omit the copy from the orig + * to the tlb buffer, if we knew for sure the device will + * overwirte the entire current content. But we don't. Thus + * unconditional bounce may prevent leaking swiotlb content (i.e. + * kernel memory) to user-space. + */ + swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE); return tlb_addr; } |