From: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> Subject: userfaultfd: replace ENOSPC with ESRCH in case mm has gone during copy/zeropage When the process exit races with outstanding mcopy_atomic, it would be better to return ESRCH error. When such race occurs the process and it's mm are going away and returning "no such process" to the uffd monitor seems better fit than ENOSPC. Link: http://lkml.kernel.org/r/1502111545-32305-1-git-send-email-rppt@xxxxxxxxxxxxxxxxxx Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> Suggested-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx> Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/userfaultfd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN fs/userfaultfd.c~userfaultfd-replace-enospc-with-esrch-in-case-mm-has-gone-during-copy-zeropage fs/userfaultfd.c --- a/fs/userfaultfd.c~userfaultfd-replace-enospc-with-esrch-in-case-mm-has-gone-during-copy-zeropage +++ a/fs/userfaultfd.c @@ -1600,7 +1600,7 @@ static int userfaultfd_copy(struct userf uffdio_copy.len); mmput(ctx->mm); } else { - return -ENOSPC; + return -ESRCH; } if (unlikely(put_user(ret, &user_uffdio_copy->copy))) return -EFAULT; @@ -1647,7 +1647,7 @@ static int userfaultfd_zeropage(struct u uffdio_zeropage.range.len); mmput(ctx->mm); } else { - return -ENOSPC; + return -ESRCH; } if (unlikely(put_user(ret, &user_uffdio_zeropage->zeropage))) return -EFAULT; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
