Re: [PATCH bpf-next 3/3] bpf: Update LSM selftests for bpf_ima_inode_hash

From: KP Singh <kpsingh@chromium.org>
To: Yonghong Song <yhs@fb.com>
Cc: James Morris <jmorris@namei.org>,
	open list <linux-kernel@vger.kernel.org>,
	bpf <bpf@vger.kernel.org>,
	Linux Security Module list 
	<linux-security-module@vger.kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Florent Revest <revest@chromium.org>,
	Brendan Jackman <jackmanb@chromium.org>,
	Mimi Zohar <zohar@linux.ibm.com>
Subject: Re: [PATCH bpf-next 3/3] bpf: Update LSM selftests for bpf_ima_inode_hash
Date: Sat, 21 Nov 2020 01:20:56 +0100	[thread overview]
Message-ID: <CACYkzJ7doNURahGQn=0d8k73USH85owoZ8yDdwtG48oQLNHYaw@mail.gmail.com> (raw)
In-Reply-To: <cad0ea25-8567-368a-1f99-b4adc7440a7f@fb.com>

On Fri, Nov 20, 2020 at 7:11 PM Yonghong Song <yhs@fb.com> wrote:
>
>
>
> On 11/20/20 5:17 AM, KP Singh wrote:
> > From: KP Singh <kpsingh@google.com>
> >
> > - Update the IMA policy before executing the test binary (this is not an
> >    override of the policy, just an append that ensures that hashes are
> >    calculated on executions).
> >
> > - Call the bpf_ima_inode_hash in the bprm_committed_creds hook and check
> >    if the call succeeded and a hash was calculated.
> >
> > Signed-off-by: KP Singh <kpsingh@google.com>
>
> LGTM with a few nits below.
>
> Acked-by: Yonghong Song <yhs@fb.com>
>
> > ---
> >   tools/testing/selftests/bpf/config            |  3 ++

[...]

> >   }
> >
> [...]
> > +
> >   void test_test_lsm(void)
> >   {
> >       struct lsm *skel = NULL;
> > @@ -66,6 +88,10 @@ void test_test_lsm(void)
> >       if (CHECK(err, "attach", "lsm attach failed: %d\n", err))
> >               goto close_prog;
> >
> > +     err = update_ima_policy();
> > +     if (CHECK(err != 0, "update_ima_policy", "error = %d\n", err))
> > +             goto close_prog;
>
> "err != 0" => err?
> "error = %d" => "err %d" for consistency with other usage in this function.

Done.

>
> > +
> >       err = exec_cmd(&skel->bss->monitored_pid);
> >       if (CHECK(err < 0, "exec_cmd", "err %d errno %d\n", err, errno))
> >               goto close_prog;
> > @@ -83,6 +109,12 @@ void test_test_lsm(void)

[...]

> >   int mprotect_count = 0;
> >   int bprm_count = 0;
> > +int ima_hash_ret = -1;
>
> The helper returns type "long", but "int" type here should be fine too.

Changed it to long for correctness.