[PATCH] i386: make pci_map_single/pci_map_sg warn for zero length.
As suggested by Linus.
This catches driver bugs that could cause corruption on IOMMU architectures.
Also I converted the BUGs to out_of_line_bug()s to save a bit
of text space.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-i386/dma-mapping.h b/include/asm-i386/dma-mapping.h
index 6c37a9a..9cf20ca 100644
--- a/include/asm-i386/dma-mapping.h
+++ b/include/asm-i386/dma-mapping.h
@@ -6,6 +6,7 @@
#include <asm/cache.h>
#include <asm/io.h>
#include <asm/scatterlist.h>
+#include <asm/bug.h>
#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
@@ -20,7 +21,9 @@
dma_map_single(struct device *dev, void *ptr, size_t size,
enum dma_data_direction direction)
{
- BUG_ON(direction == DMA_NONE);
+ if (direction == DMA_NONE)
+ BUG();
+ WARN_ON(size == 0);
flush_write_buffers();
return virt_to_phys(ptr);
}
@@ -29,7 +32,8 @@
dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
enum dma_data_direction direction)
{
- BUG_ON(direction == DMA_NONE);
+ if (direction == DMA_NONE)
+ BUG();
}
static inline int
@@ -38,7 +42,9 @@
{
int i;
- BUG_ON(direction == DMA_NONE);
+ if (direction == DMA_NONE)
+ BUG();
+ WARN_ON(nents == 0 || sg[0].length == 0);
for (i = 0; i < nents; i++ ) {
BUG_ON(!sg[i].page);
