dma: kmsan: unpoison DMA mappings

KMSAN doesn't know about DMA memory writes performed by devices.  We
unpoison such memory when it's mapped to avoid false positive reports.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Alexander Potapenko <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Andrey Konovalov <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Eric Biggers <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Ilya Leoshkevich <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Michael S. Tsirkin <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Cc: Vegard Nossum <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

1 files changed, 7 insertions, 3 deletions

diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 49cbf3e33de7..a8400aa9bcd4 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -10,6 +10,7 @@
 #include <linux/dma-map-ops.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
+#include <linux/kmsan.h>
 #include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
@@ -156,6 +157,7 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page,
 		addr = dma_direct_map_page(dev, page, offset, size, dir, attrs);
 	else
 		addr = ops->map_page(dev, page, offset, size, dir, attrs);
+	kmsan_handle_dma(page, offset, size, dir);
 	debug_dma_map_page(dev, page, offset, size, dir, addr, attrs);
 
 	return addr;
@@ -194,11 +196,13 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
 	else
 		ents = ops->map_sg(dev, sg, nents, dir, attrs);
 
-	if (ents > 0)
+	if (ents > 0) {
+		kmsan_handle_dma_sg(sg, nents, dir);
 		debug_dma_map_sg(dev, sg, nents, ents, dir, attrs);
-	else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM &&
-			      ents != -EIO && ents != -EREMOTEIO))
+	} else if (WARN_ON_ONCE(ents != -EINVAL && ents != -ENOMEM &&
+				ents != -EIO && ents != -EREMOTEIO)) {
 		return -EIO;
+	}
 
 	return ents;
 }