dma-debug: make memory range checks more consistent

Impact: extend on-kernel-stack DMA debug checks to all !highmem pages

We only checked dma_map_single() - extend it to dma_map_page()
and dma_map_sg() as well.

Also, fix dma_map_single() corner case bug: make sure we dont
stack-check highmem (not mapped) pages.

Reported-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
LKML-Reference: <1237818908-26516-1-git-send-email-joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 5 deletions

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index f9e6d38b4b34..1a992089486c 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -722,10 +722,11 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
         entry->size      = size;
         entry->direction = direction;
 
-        if (map_single) {
-                void *addr = ((char *)page_address(page)) + offset;
-
+        if (map_single)
                 entry->type = dma_debug_single;
+
+        if (!PageHighMem(page)) {
+                void *addr = ((char *)page_address(page)) + offset;
                 check_for_stack(dev, addr);
                 check_for_illegal_area(dev, addr, size);
         }
@@ -779,8 +780,10 @@ void debug_dma_map_sg(struct device *dev, struct scatterlist *sg,
                 entry->sg_call_ents   = nents;
                 entry->sg_mapped_ents = mapped_ents;
 
-                check_for_stack(dev, sg_virt(s));
-                check_for_illegal_area(dev, sg_virt(s), s->length);
+                if (!PageHighMem(sg_page(s))) {
+                        check_for_stack(dev, sg_virt(s));
+                        check_for_illegal_area(dev, sg_virt(s), s->length);
+                }
 
                 add_dma_entry(entry);
         }