Re: [PATCH] selftests/harness: Fix TEST_F()'s vfork handling

From: "Mickaël Salaün" <mic@digikod.net>
To: Jakub Kicinski <kuba@kernel.org>
Cc: "David S . Miller" <davem@davemloft.net>,
	"Kees Cook" <keescook@chromium.org>,
	"Mark Brown" <broonie@kernel.org>,
	"Shuah Khan" <shuah@kernel.org>,
	"Günther Noack" <gnoack@google.com>,
	"Will Drewry" <wad@chromium.org>,
	edumazet@google.com, jakub@cloudflare.com, pabeni@redhat.com,
	linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
	linux-security-module@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH] selftests/harness: Fix TEST_F()'s vfork handling
Date: Wed, 6 Mar 2024 08:32:13 +0100	[thread overview]
Message-ID: <20240306.aepaGah0tie2@digikod.net> (raw)
In-Reply-To: <20240306.Hei7aekahvaj@digikod.net>

On Wed, Mar 06, 2024 at 08:25:45AM +0100, Mickaël Salaün wrote:
> On Tue, Mar 05, 2024 at 12:25:54PM -0800, Jakub Kicinski wrote:
> > On Tue,  5 Mar 2024 21:10:29 +0100 Mickaël Salaün wrote:
> > > Always run fixture setup in the grandchild process, and by default also
> > > run the teardown in the same process.  However, this change makes it
> > > possible to run the teardown in a parent process when
> > > _metadata->teardown_parent is set to true (e.g. in fixture setup).
> > > 
> > > Fix TEST_SIGNAL() by forwarding grandchild's signal to its parent.  Fix
> > > seccomp tests by running the test setup in the parent of the test
> > > thread, as expected by the related test code.  Fix Landlock tests by
> > > waiting for the grandchild before processing _metadata.
> > > 
> > > Use of exit(3) in tests should be OK because the environment in which
> > > the vfork(2) call happen is already dedicated to the running test (with
> > > flushed stdio, setpgrp() call), see __run_test() and the call to fork(2)
> > > just before running the setup/test/teardown.  Even if the test
> > > configures its own exit handlers, they will not be run by the parent
> > > because it never calls exit(3), and the test function either ends with a
> > > call to _exit(2) or a signal.
> > > 
> > > Cc: David S. Miller <davem@davemloft.net>
> > > Cc: Günther Noack <gnoack@google.com>
> > > Cc: Jakub Kicinski <kuba@kernel.org>
> > > Cc: Kees Cook <keescook@chromium.org>
> > > Cc: Mark Brown <broonie@kernel.org>
> > > Cc: Shuah Khan <shuah@kernel.org>
> > > Cc: Will Drewry <wad@chromium.org>
> > > Fixes: 0710a1a73fb4 ("selftests/harness: Merge TEST_F_FORK() into TEST_F()")
> > > Link: https://lore.kernel.org/r/20240305201029.1331333-1-mic@digikod.net
> 
> Signed-off-by: Mickaël Salaün <mic@digikod.net>

Reported-by: Mark Brown <broonie@kernel.org>

> 
> > 
> > Your S-o-b is missing. Should be enough if you responded with it.
> > 
> > Code LGTM, thanks!
> >