Re: [PATCH 05/10] x86: add check code for map/unmap_single code

On Sat, Nov 22, 2008 at 12:27:41PM +0900, FUJITA Tomonori wrote:

On Fri, 21 Nov 2008 17:26:05 +0100
Joerg Roedel [off-list ref] wrote:

quoted

Impact: detect bugs in map/unmap_single usage

Signed-off-by: Joerg Roedel <redacted>
---
 arch/x86/include/asm/dma-mapping.h |    9 +++++-
 arch/x86/include/asm/dma_debug.h   |   20 +++++++++++++
 arch/x86/kernel/pci-dma-debug.c    |   55 ++++++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 83d7b7d..c9bead2 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h

@@ -98,9 +98,14 @@ dma_map_single(struct device *hwdev, void *ptr, size_t size,
 	       int direction)
 {
 	struct dma_mapping_ops *ops = get_dma_ops(hwdev);
+	dma_addr_t addr;
 
 	BUG_ON(!valid_dma_direction(direction));
-	return ops->map_single(hwdev, virt_to_phys(ptr), size, direction);
+	addr = ops->map_single(hwdev, virt_to_phys(ptr), size, direction);
+
+	debug_map_single(hwdev, ptr, size, direction, addr);

debug_map_single could fail due to OOM. Then debug_unmap_single in
dma_unmap_single gives a false warning because it can't find the
dma_debug_entry?

True. I will add a check to disable checking when a map operation has
failed.

Joerg