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From: "Günther Noack" <gnoack3000@gmail.com>
To: Alejandro Colomar <alx.manpages@gmail.com>
Cc: "Mickaël Salaün" <mic@digikod.net>,
	"Michael Kerrisk" <mtk.manpages@gmail.com>,
	linux-man@vger.kernel.org
Subject: Re: [PATCH v7 1/1] landlock.7: Explain the best-effort fallback mechanism in the example
Date: Wed, 19 Apr 2023 20:21:50 +0200	[thread overview]
Message-ID: <20230419.704027e98f41@gnoack.org> (raw)
In-Reply-To: <84d7c516-41c2-cac6-b5f4-2348eb7201a9@gmail.com>

On Tue, Apr 18, 2023 at 04:24:49PM +0200, Alejandro Colomar wrote:
> Hi Mickaël,
> 
> On 4/17/23 22:45, Mickaël Salaün wrote:
> 
> [...]
> 
> >> +int abi = landlock_create_ruleset(NULL, 0,
> >> +                                  LANDLOCK_CREATE_RULESET_VERSION);
> >> +if (abi <= 0) {
> >> +    /*
> >> +     * Kernel too old, not compiled with Landlock,
> >> +     * or Landlock was not enabled at boot time.
> >> +     */
> >> +    perror("Giving up \- No Landlock support");
> 
> [...]
> 
> > As a side note, this syscall and this flag should never return 0, but if 
> > it does (e.g. because of weird seccomp filter), the errno value might be 
> > unspecified.
> 
> Hmm, good catch, we should test for `== -1`, rather than `< 0`.
> Michael Kerrisk explicitly wanted this, and I agree with him, as it makes
> the code slightly more readable (explicit).

Ack, I'll send a small follow-up.

–Günther


  reply	other threads:[~2023-04-19 18:22 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-04-17 17:25 [PATCH v7 0/1] landlock.7: Explain best-effort fallback in example Günther Noack
2023-04-17 17:25 ` [PATCH v7 1/1] landlock.7: Explain the best-effort fallback mechanism in the example Günther Noack
2023-04-17 20:45   ` Mickaël Salaün
2023-04-18 14:24     ` Alejandro Colomar
2023-04-19 18:21       ` Günther Noack [this message]
2023-04-17 18:50 ` [PATCH v7 0/1] landlock.7: Explain best-effort fallback in example Alejandro Colomar

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