From: Hugh Dickins Date: Thu, 10 Nov 2016 18:46:11 +0000 (-0800) Subject: shmem: fix pageflags after swapping DMA32 object X-Git-Tag: v4.8.9~86 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c87739e5d029a61ef1bbaccd90d07194459f9640;p=thirdparty%2Fkernel%2Fstable.git shmem: fix pageflags after swapping DMA32 object commit 9956edf37e65e93fbb76dcff1236dff2323d306a upstream. 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- diff --git a/mm/shmem.c b/mm/shmem.c index 971fc83e64028..38aa5e0a955f6 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);