Unfortunately, we ended up with the wrong version of the patch "fix info leak with DMA_FROM_DEVICE" getting merged. We got v4 merged, but the version we want is v7 with some minor tweaks which were supposed to be applied by Christoph (swiotlb maintainer). After pointing this out, I was asked by Christoph to create an incremental fix.
IMHO the cleanest way to do this is a reverting the incorrect version of the patch and applying the correct one. I hope that qualifies as an incremental fix.
The main differences between what we got and what we need are: * swiotlb_sync_single_for_device is also required to do an extra bounce * It was decided that we want to defer introducing DMA_ATTR_OVERWRITE, until we have exploiters * And anyway DMA_ATTR_OVERWRITE must take precedence over DMA_ATTR_SKIP_CPU_SYNC, so the v4 implementation of DMA_ATTR_OVERWRITE ain't even orrect.
Halil Pasic (2): Revert "swiotlb: fix info leak with DMA_FROM_DEVICE" swiotlb: fix info leak with DMA_FROM_DEVICE
Documentation/core-api/dma-attributes.rst | 8 -------- include/linux/dma-mapping.h | 8 -------- kernel/dma/swiotlb.c | 23 +++++++++++++++-------- 3 files changed, 15 insertions(+), 24 deletions(-)
base-commit: 38f80f42147ff658aff218edb0a88c37e58bf44f