lkml.org 
[lkml]   [2015]   [Sep]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/4] dmapool: Fix overflow condition in pool_find_page
Date
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>
---
mm/dmapool.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/dmapool.c b/mm/dmapool.c
index 71a8998..312a716 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;
--
1.9.1


\
 
 \ /
  Last update: 2015-09-25 14:21    [W:0.112 / U:0.032 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site