X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=mm%2Fmemory.c;h=0e18b4d649ec82abc83c208e5f9dce9cbb2cf905;hb=6e1bd1ab1d9ab8e83cdc940df82fbf8418e2593f;hp=71b161b73bb503be50556e9ff302ca0c7eaba396;hpb=df423dc7f2a801b9a45d7c501a8eb5c529455ea1;p=~andy%2Flinux

diff --git a/mm/memory.c b/mm/memory.c
index 71b161b73bb..0e18b4d649e 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2680,10 +2680,12 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
 
 	/*
-	 * Make sure try_to_free_swap didn't release the swapcache
-	 * from under us. The page pin isn't enough to prevent that.
+	 * Make sure try_to_free_swap or reuse_swap_page or swapoff did not
+	 * release the swapcache from under us.  The page pin, and pte_same
+	 * test below, are not enough to exclude that.  Even if it is still
+	 * swapcache, we need to check that the page's swap has not changed.
 	 */
-	if (unlikely(!PageSwapCache(page)))
+	if (unlikely(!PageSwapCache(page) || page_private(page) != entry.val))
 		goto out_page;
 
 	if (ksm_might_need_to_copy(page, vma, address)) {