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Date:   Fri, 29 Sep 2023 10:06:14 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Pedro Falcato <pedro.falcato@gmail.com>
Cc:     Eric Biederman <ebiederm@xmission.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Christian Brauner <brauner@kernel.org>,
        linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
        Sebastian Ott <sebott@redhat.com>,
        Thomas =?iso-8859-1?Q?Wei=DFschuh?= <linux@weissschuh.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org,
        linux-arch@vger.kernel.org
Subject: Re: [PATCH v4 4/6] binfmt_elf: Use elf_load() for library
Message-ID: <202309291005.80DD5F55E9@keescook>
References: <20230929031716.it.155-kees@kernel.org>
 <20230929032435.2391507-4-keescook@chromium.org>
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On Fri, Sep 29, 2023 at 01:12:13PM +0100, Pedro Falcato wrote:
> On Fri, Sep 29, 2023 at 4:24 AM Kees Cook <keescook@chromium.org> wrote:
> >
> > While load_elf_library() is a libc5-ism, we can still replace most of
> > its contents with elf_load() as well, further simplifying the code.
> 
> While I understand you want to break as little as possible (as the ELF
> loader maintainer), I'm wondering if we could axe CONFIG_USELIB
> altogether? Since CONFIG_BINFMT_AOUT also got axed. Does this have
> users anywhere?

I can't even find a libc5 image I can test. :P

I made it non-default in '22:

7374fa33dc2d ("init/Kconfig: remove USELIB syscall by default")

I'm not sure we can drop it entirely, though.

-- 
Kees Cook