https://github.com/torvalds/linux
Revision dcf7fe9d89763a28e0f43975b422ff141fe79e43 authored by Andrea Arcangeli on 30 November 2018, 22:09:43 UTC, committed by Linus Torvalds on 30 November 2018, 22:56:14 UTC
Set the page dirty if VM_WRITE is not set because in such case the pte
won't be marked dirty and the page would be reclaimed without writepage
(i.e. swapout in the shmem case).
This was found by source review. Most apps (certainly including QEMU)
only use UFFDIO_COPY on PROT_READ|PROT_WRITE mappings or the app can't
modify the memory in the first place. This is for correctness and it
could help the non cooperative use case to avoid unexpected data loss.
Link: http://lkml.kernel.org/r/20181126173452.26955-6-aarcange@redhat.com
Reviewed-by: Hugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org
Fixes: 4c27fe4c4c84 ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support")
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent e2a50c1
Tip revision: dcf7fe9d89763a28e0f43975b422ff141fe79e43 authored by Andrea Arcangeli on 30 November 2018, 22:09:43 UTC
userfaultfd: shmem: UFFDIO_COPY: set the page dirty if VM_WRITE is not set
userfaultfd: shmem: UFFDIO_COPY: set the page dirty if VM_WRITE is not set
Tip revision: dcf7fe9
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| crypto | ||
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| include | ||
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| kernel | ||
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| .clang-format | -rw-r--r-- | 12.7 KB |
| .cocciconfig | -rw-r--r-- | 59 bytes |
| .get_maintainer.ignore | -rw-r--r-- | 31 bytes |
| .gitattributes | -rw-r--r-- | 30 bytes |
| .gitignore | -rw-r--r-- | 1.5 KB |
| .mailmap | -rw-r--r-- | 10.5 KB |
| COPYING | -rw-r--r-- | 423 bytes |
| CREDITS | -rw-r--r-- | 96.6 KB |
| Kbuild | -rw-r--r-- | 2.2 KB |
| Kconfig | -rw-r--r-- | 563 bytes |
| MAINTAINERS | -rw-r--r-- | 472.8 KB |
| Makefile | -rw-r--r-- | 59.7 KB |
| README | -rw-r--r-- | 727 bytes |
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