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shmem: fix pageflags after swapping DMA32 object

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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 <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>	[4.8.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Hugh Dickins 2016-11-10 10:46:11 -08:00 committed by Linus Torvalds
parent 5e322beefc
commit 9956edf37e
1 changed files with 2 additions and 0 deletions
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2
mm/shmem.c
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@ -1483,6 +1483,8 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
copy_highpage(newpage, oldpage); copy_highpage(newpage, oldpage);
flush_dcache_page(newpage); flush_dcache_page(newpage);
__SetPageLocked(newpage);
__SetPageSwapBacked(newpage);
SetPageUptodate(newpage); SetPageUptodate(newpage);
set_page_private(newpage, swap_index); set_page_private(newpage, swap_index);
SetPageSwapCache(newpage); SetPageSwapCache(newpage);