The patch titled
Subject: userfaultfd: shmem: lock the page before adding it to pagecache
has been added to the -mm tree. Its filename is
userfaultfd-shmem-lock-the-page-before-adding-it-to-pagecache.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/userfaultfd-shmem-lock-the-page-before-adding-it-to-pagecache.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/userfaultfd-shmem-lock-the-page-before-adding-it-to-pagecache.patch
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------------------------------------------------------
From: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Subject: 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@xxxxxxxxxx
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>
Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>
Cc: Michael Rapoport <RAPOPORT@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/shmem.c | 5 +++++
1 file changed, 5 insertions(+)
diff -puN mm/shmem.c~userfaultfd-shmem-lock-the-page-before-adding-it-to-pagecache mm/shmem.c
--- a/mm/shmem.c~userfaultfd-shmem-lock-the-page-before-adding-it-to-pagecache
+++ a/mm/shmem.c
@@ -2238,6 +2238,10 @@ int shmem_mcopy_atomic_pte(struct mm_str
*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;
@@ -2287,6 +2291,7 @@ out_release_uncharge_unlock:
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)
_
Patches currently in -mm which might be from aarcange@xxxxxxxxxx are
userfaultfd-document-_ior-_iow.patch
userfaultfd-correct-comment-about-uffd_feature_pagefault_flag_wp.patch
userfaultfd-convert-bug-to-warn_on_once.patch
userfaultfd-use-vma_is_anonymous.patch
userfaultfd-non-cooperative-report-all-available-features-to-userland.patch
userfaultfd-non-cooperative-add-fork-event-build-warning-fix.patch
userfaultfd-non-cooperative-optimize-mremap_userfaultfd_complete.patch
userfaultfd-non-cooperative-avoid-madv_dontneed-race-condition.patch
userfaultfd-non-cooperative-wake-userfaults-after-uffdio_unregister.patch
userfaultfd-hugetlbfs-gup-support-vm_fault_retry.patch
userfaultfd-hugetlbfs-uffd_feature_missing_hugetlbfs.patch
userfaultfd-shmem-add-tlbflushh-header-for-microblaze.patch
userfaultfd-shmem-lock-the-page-before-adding-it-to-pagecache.patch
userfaultfd-shmem-avoid-leaking-blocks-and-used-blocks-in-uffdio_copy.patch
userfaultfd-hugetlbfs-uffd_feature_missing_shmem.patch
userfaultfd-selftest-test-uffdio_zeropage-on-all-memory-types.patch
mm-mprotect-use-pmd_trans_unstable-instead-of-taking-the-pmd_lock.patch
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