From 9956edf37e65e93fbb76dcff1236dff2323d306a Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 10 Nov 2016 10:46:11 -0800 Subject: [PATCH] shmem: fix pageflags after swapping DMA32 object If shmem_alloc_page() does not set PageLocked and PageSwapBacked, then shmem_replace_page() needs to do so for itself. Without this, it puts newpage on the wrong lru, re-unlocks the unlocked newpage, and system descends into "Bad page" reports and freeze; or if CONFIG_DEBUG_VM=y, it hits an earlier VM_BUG_ON_PAGE(!PageLocked), depending on config. But shmem_replace_page() is not a common path: it's only called when swapin (or swapoff) finds the page was already read into an unsuitable zone: usually all zones are suitable, but gem objects for a few drm devices (gma500, omapdrm, crestline, broadwater) require zone DMA32 if there's more than 4GB of ram. Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1611062003510.11253@eggly.anvils Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Cc: [4.8.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/shmem.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/shmem.c b/mm/shmem.c index ad7813d73ea7..166ebf5d2bce 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1483,6 +1483,8 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp, copy_highpage(newpage, oldpage); flush_dcache_page(newpage); + __SetPageLocked(newpage); + __SetPageSwapBacked(newpage); SetPageUptodate(newpage); set_page_private(newpage, swap_index); SetPageSwapCache(newpage); -- 2.20.1