Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Sun, 10 Oct 2021 14:48:14 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     =?ISO-8859-1?Q?Micka=EBl_Sala=FCn?= <mic@digikod.net>
Cc:     Al Viro <viro@zeniv.linux.org.uk>,
        Aleksa Sarai <cyphar@cyphar.com>,
        Andy Lutomirski <luto@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Casey Schaufler <casey@schaufler-ca.com>,
        Christian Brauner <christian.brauner@ubuntu.com>,
        Christian Heimes <christian@python.org>,
        Deven Bowers <deven.desai@linux.microsoft.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Eric Biggers <ebiggers@kernel.org>,
        Eric Chiang <ericchiang@google.com>,
        Florian Weimer <fweimer@redhat.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        James Morris <jmorris@namei.org>, Jan Kara <jack@suse.cz>,
        Jann Horn <jannh@google.com>, Jonathan Corbet <corbet@lwn.net>,
        Kees Cook <keescook@chromium.org>,
        Lakshmi Ramasubramanian <nramas@linux.microsoft.com>,
        "Madhavan T . Venkataraman" <madvenka@linux.microsoft.com>,
        Matthew Garrett <mjg59@google.com>,
        Matthew Wilcox <willy@infradead.org>,
        Miklos Szeredi <mszeredi@redhat.com>,
        Mimi Zohar <zohar@linux.ibm.com>,
        Paul Moore <paul@paul-moore.com>,
        Philippe =?ISO-8859-1?Q?Tr=E9buchet?= 
        <philippe.trebuchet@ssi.gouv.fr>,
        Scott Shell <scottsh@microsoft.com>,
        Shuah Khan <shuah@kernel.org>,
        Steve Dower <steve.dower@python.org>,
        Steve Grubb <sgrubb@redhat.com>,
        Thibaut Sautereau <thibaut.sautereau@ssi.gouv.fr>,
        Vincent Strubel <vincent.strubel@ssi.gouv.fr>,
        kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-integrity@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org
Subject: Re: [PATCH v14 0/3] Add trusted_for(2) (was O_MAYEXEC)
Message-Id: <20211010144814.d9fb99de6b0af65b67dc96cb@linux-foundation.org>
In-Reply-To: <20211008104840.1733385-1-mic@digikod.net>
References: <20211008104840.1733385-1-mic@digikod.net>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Fri,  8 Oct 2021 12:48:37 +0200 Micka=EBl Sala=FCn <mic@digikod.net> wro=
te:

> The final goal of this patch series is to enable the kernel to be a
> global policy manager by entrusting processes with access control at
> their level.  To reach this goal, two complementary parts are required:
> * user space needs to be able to know if it can trust some file
>   descriptor content for a specific usage;
> * and the kernel needs to make available some part of the policy
>   configured by the system administrator.

Apologies if I missed this...

It would be nice to see a description of the proposed syscall interface
in these changelogs!  Then a few questions I have will be answered...

long trusted_for(const int fd,
		 const enum trusted_for_usage usage,
		 const u32 flags)

- `usage' must be equal to TRUSTED_FOR_EXECUTION, so why does it
  exist?  Some future modes are planned?  Please expand on this.

- `flags' is unused (must be zero).  So why does it exist?  What are
  the plans here?

- what values does the syscall return and what do they mean?