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| author | Mike Rapoport <rppt@linux.vnet.ibm.com> | 2017-02-24 14:58:31 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-24 17:46:55 -0800 |
| commit | 96333187ab16215888f2bce01985ca5a823da8ba (patch) | |
| tree | 7eb8866b6d2ab89b0bf058c3963089095049e893 /fs/userfaultfd.c | |
| parent | 27d02568f529e908399514dfbee8ee43bdfd5299 (diff) | |
| download | linux-96333187ab16215888f2bce01985ca5a823da8ba.tar.gz linux-96333187ab16215888f2bce01985ca5a823da8ba.tar.bz2 linux-96333187ab16215888f2bce01985ca5a823da8ba.zip | |
userfaultfd_copy: return -ENOSPC in case mm has gone
In the non-cooperative userfaultfd case, the process exit may race with
outstanding mcopy_atomic called by the uffd monitor. Returning -ENOSPC
instead of -EINVAL when mm is already gone will allow uffd monitor to
distinguish this case from other error conditions.
Link: http://lkml.kernel.org/r/1485542673-24387-6-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/userfaultfd.c')
| -rw-r--r-- | fs/userfaultfd.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index b676575f2268..625b7285a37b 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1607,6 +1607,8 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, ret = mcopy_atomic(ctx->mm, uffdio_copy.dst, uffdio_copy.src, uffdio_copy.len); mmput(ctx->mm); + } else { + return -ENOSPC; } if (unlikely(put_user(ret, &user_uffdio_copy->copy))) return -EFAULT; |