Commit 41e20983 authored Oct 26, 2009 by Wu Fengguang Committed by Linus Torvalds Oct 29, 2009

vmscan: limit VM_EXEC protection to file pages



It is possible to have !Anon but SwapBacked pages, and some apps could
create huge number of such pages with MAP_SHARED|MAP_ANONYMOUS.  These
pages go into the ANON lru list, and hence shall not be protected: we only
care mapped executable files.  Failing to do so may trigger OOM.

Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent b76146ed

mm/vmscan.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1356,7 +1356,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
		* IO, plus JVM can create lots of anon VM_EXEC pages,
		* so we ignore them here.
		*/
		if ((vm_flags & VM_EXEC) && !PageAnon(page)) {
		if ((vm_flags & VM_EXEC) && page_is_file_cache(page)) {
		list_add(&page->lru, &l_active);
		continue;
		}