6 new syscalls without tests (was: [PATCH] vfs: move_mount: reject moving kernel internal mounts)

From: Eric Biggers
Date: Tue Jul 09 2019 - 23:23:17 EST


On Tue, Jul 09, 2019 at 09:54:24PM +0100, Al Viro wrote:
> On Tue, Jul 09, 2019 at 12:40:01PM -0700, Eric Biggers wrote:
> > On Tue, Jul 02, 2019 at 11:22:59AM -0700, Eric Biggers wrote:
> > >
> > > Sure, but the new mount syscalls still need tests. Where are the tests?
> > >
> >
> > Still waiting for an answer to this question.
>
> In samples/vfs/fsmount.c, IIRC, and that's not much of a test.

A sample program doesn't count. There need to be tests that can be run
automatically as part of a well known test suite, such as LTP, kselftests, or
xfstests. Why is this not mandatory for new syscalls to be accepted? What if
they are broken and we don't know? See what happened with copy_file_range():
https://lwn.net/Articles/774114/

- Eric