[tip:core/iommu] dma-debug: warn of unmapping an invalid dma address

[FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>]

Commit-ID:  35d40952dba7b0689a16bd1463fb7698f8dbe639
Gitweb:     http://git.kernel.org/tip/35d40952dba7b0689a16bd1463fb7698f8dbe639
Author:     FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
AuthorDate: Thu, 19 Mar 2009 10:39:31 +0900
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Thu, 19 Mar 2009 08:39:48 +0100

dma-debug: warn of unmapping an invalid dma address

Impact: extend DMA-debug checks

Calling dma_unmap families against an invalid dma address should be a
bug.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Joerg Roedel <joerg.roedel@amd.com>
LKML-Reference: <20090319103743N.fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 lib/dma-debug.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 9a350b4..f9e6d38 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -531,8 +531,11 @@ static void check_unmap(struct dma_debug_entry *ref)
 	struct hash_bucket *bucket;
 	unsigned long flags;
 
-	if (dma_mapping_error(ref->dev, ref->dev_addr))
+	if (dma_mapping_error(ref->dev, ref->dev_addr)) {
+		err_printk(ref->dev, NULL, "DMA-API: device driver tries "
+			   "to free an invalid DMA memory address\n");
 		return;
+	}
 
 	bucket = get_hash_bucket(ref, &flags);
 	entry = hash_bucket_find(bucket, ref);