Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9cc90c66 authored by Andrea Arcangeli's avatar Andrea Arcangeli Committed by Linus Torvalds
Browse files

userfaultfd: shmem: lock the page before adding it to pagecache 

A VM_BUG_ON triggered on the shmem selftest.

Link: http://lkml.kernel.org/r/20161216144821.5183-36-aarcange@redhat.com


Signed-off-by: default avatarAndrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Michael Rapoport <RAPOPORT@il.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 419624da

mm/shmem.c

+5 −0
Original line number Diff line number Diff line
@@ -2245,6 +2245,10 @@ int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, 
		*pagep = NULL;

	}



	VM_BUG_ON(PageLocked(page) || PageSwapBacked(page));

	__SetPageLocked(page);

	__SetPageSwapBacked(page);



	ret = mem_cgroup_try_charge(page, dst_mm, gfp, &memcg, false);

	if (ret)

		goto out_release;
@@ -2294,6 +2298,7 @@ int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, 
out_release_uncharge:

	mem_cgroup_cancel_charge(page, memcg, false);

out_release:

	unlock_page(page);

	put_page(page);

out_dec_used_blocks:

	if (sbinfo->max_blocks)