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authorStephen Boyd <swboyd@chromium.org>2018-10-08 10:20:07 +0300
committerChristoph Hellwig <hch@lst.de>2018-10-08 10:44:17 +0300
commit99c65fa7c59ff558e70db8aa61bbdece5d3a9588 (patch)
tree5a72a54e4d6d2104b3aeedd86d84563d2d545af5 /include/linux/dma-mapping.h
parent1fc8e6423edb4bba365b0780c2fcddfb921b24b2 (diff)
downloadlinux-99c65fa7c59ff558e70db8aa61bbdece5d3a9588.tar.xz
dma-debug: Check for drivers mapping invalid addresses in dma_map_single()
I recently debugged a DMA mapping oops where a driver was trying to map a buffer returned from request_firmware() with dma_map_single(). Memory returned from request_firmware() is mapped into the vmalloc region and this isn't a valid region to map with dma_map_single() per the DMA documentation's "What memory is DMA'able?" section. Unfortunately, we don't really check that in the DMA debugging code, so enabling DMA debugging doesn't help catch this problem. Let's add a new DMA debug function to check for a vmalloc address or an invalid virtual address and print a warning if this happens. This makes it a little easier to debug these sorts of problems, instead of seeing odd behavior or crashes when drivers attempt to map the vmalloc space for DMA. Cc: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'include/linux/dma-mapping.h')
-rw-r--r--include/linux/dma-mapping.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 562af6b45f23..547a48bcfa3d 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -229,6 +229,7 @@ static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
dma_addr_t addr;
BUG_ON(!valid_dma_direction(dir));
+ debug_dma_map_single(dev, ptr, size);
addr = ops->map_page(dev, virt_to_page(ptr),
offset_in_page(ptr), size,
dir, attrs);