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authorRobin Murphy <robin.murphy@arm.com>2015-10-01 15:37:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-10-01 21:42:35 -0400
commit676bd99178cd962ed24ffdad222b7069d330a969 (patch)
treeca76fb3382ada58d059dae22fb60f18b7437c8d4
parent44241628bb207ec211bebd156aaf69470d90c209 (diff)
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dmapool: fix overflow condition in pool_find_page()
If a DMA pool lies at the very top of the dma_addr_t range (as may happen with an IOMMU involved), the calculated end address of the pool wraps around to zero, and page lookup always fails. Tweak the relevant calculation to be overflow-proof. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Sakari Ailus <sakari.ailus@iki.fi> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/dmapool.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/dmapool.c b/mm/dmapool.c
index 71a8998cd03a..312a716fa14c 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -394,7 +394,7 @@ static struct dma_page *pool_find_page(struct dma_pool *pool, dma_addr_t dma)
list_for_each_entry(page, &pool->page_list, page_list) {
if (dma < page->dma)
continue;
- if (dma < (page->dma + pool->allocation))
+ if ((dma - page->dma) < pool->allocation)
return page;
}
return NULL;