On Thu 27-07-17 09:26:59, Mike Rapoport wrote: > 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.
Normally we tend to return ESRCH in such case. ENOSPC sounds rather confusing... > Cc: [email protected] > Fixes: 96333187ab162 ("userfaultfd_copy: return -ENOSPC in case mm has gone") > > Signed-off-by: Mike Rapoport <[email protected]> > --- > > Unfortunately, I've overlooked userfaultfd_zeropage when I updated > userfaultd_copy :( > > fs/userfaultfd.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c > index cadcd12a3d35..2d8c2d848668 100644 > --- a/fs/userfaultfd.c > +++ b/fs/userfaultfd.c > @@ -1643,6 +1643,8 @@ static int userfaultfd_zeropage(struct userfaultfd_ctx > *ctx, > ret = mfill_zeropage(ctx->mm, uffdio_zeropage.range.start, > uffdio_zeropage.range.len); > mmput(ctx->mm); > + } else { > + return -ENOSPC; > } > if (unlikely(put_user(ret, &user_uffdio_zeropage->zeropage))) > return -EFAULT; > -- > 2.7.4 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to [email protected]. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"[email protected]";> [email protected] </a> -- Michal Hocko SUSE Labs
