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authorLaura Abbott <lauraa@codeaurora.org>2015-03-25 15:55:26 -0700
committerSasha Levin <sasha.levin@oracle.com>2015-04-24 17:13:43 -0400
commita38edfb21325d2397dc08c76258682a8b7a51028 (patch)
tree14dfb1035dd682d20e8be8b00dd35676bc2ddbab /mm
parentec4db2665afe7cf1f903fa9bc4e924164813cc2d (diff)
downloadlinux-rt-a38edfb21325d2397dc08c76258682a8b7a51028.tar.gz
mm/page_alloc.c: call kernel_map_pages in unset_migrateype_isolate
[ Upstream commit cfa869438282be84ad4110bba5027ef1fbbe71e4 ] Commit 3c605096d315 ("mm/page_alloc: restrict max order of merging on isolated pageblock") changed the logic of unset_migratetype_isolate to check the buddy allocator and explicitly call __free_pages to merge. The page that is being freed in this path never had prep_new_page called so set_page_refcounted is called explicitly but there is no call to kernel_map_pages. With the default kernel_map_pages this is mostly harmless but if kernel_map_pages does any manipulation of the page tables (unmapping or setting pages to read only) this may trigger a fault: alloc_contig_range test_pages_isolated(ceb00, ced00) failed Unable to handle kernel paging request at virtual address ffffffc0cec00000 pgd = ffffffc045fc4000 [ffffffc0cec00000] *pgd=0000000000000000 Internal error: Oops: 9600004f [#1] PREEMPT SMP Modules linked in: exfatfs CPU: 1 PID: 23237 Comm: TimedEventQueue Not tainted 3.10.49-gc72ad36-dirty #1 task: ffffffc03de52100 ti: ffffffc015388000 task.ti: ffffffc015388000 PC is at memset+0xc8/0x1c0 LR is at kernel_map_pages+0x1ec/0x244 Fix this by calling kernel_map_pages to ensure the page is set in the page table properly Fixes: 3c605096d315 ("mm/page_alloc: restrict max order of merging on isolated pageblock") Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Gioh Kim <gioh.kim@lge.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'mm')
-rw-r--r--mm/page_isolation.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index c8778f7e208e..ec66134fb2a5 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -103,6 +103,7 @@ void unset_migratetype_isolate(struct page *page, unsigned migratetype)
if (!is_migrate_isolate_page(buddy)) {
__isolate_free_page(page, order);
+ kernel_map_pages(page, (1 << order), 1);
set_page_refcounted(page);
isolated_page = page;
}