Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) client-ip=2620:137:e000::3:6;
Message-ID: <e673d8d6-bfa8-be30-d1c1-fe09b5f811e3@redhat.com>
Date:   Fri, 6 Oct 2023 14:07:16 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.15.1
Subject: Re: [RFC PATCH 0/2] Introduce a way to expose the interpreted file
 with binfmt_misc
Content-Language: en-US
To:     "Guilherme G. Piccoli" <gpiccoli@igalia.com>,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc:     linux-mm@kvack.org, kernel-dev@igalia.com, kernel@gpiccoli.net,
        keescook@chromium.org, ebiederm@xmission.com, oleg@redhat.com,
        yzaikin@google.com, mcgrof@kernel.org, akpm@linux-foundation.org,
        brauner@kernel.org, viro@zeniv.linux.org.uk, willy@infradead.org,
        dave@stgolabs.net, sonicadvance1@gmail.com, joshua@froggi.es
References: <20230907204256.3700336-1-gpiccoli@igalia.com>
From:   David Hildenbrand <david@redhat.com>
Organization: Red Hat
In-Reply-To: <20230907204256.3700336-1-gpiccoli@igalia.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 07.09.23 22:24, Guilherme G. Piccoli wrote:
> Currently the kernel provides a symlink to the executable binary, in the
> form of procfs file exe_file (/proc/self/exe_file for example). But what
> happens in interpreted scenarios (like binfmt_misc) is that such link
> always points to the *interpreter*. For cases of Linux binary emulators,
> like FEX [0] for example, it's then necessary to somehow mask that and
> emulate the true binary path.

I'm absolutely no expert on that, but I'm wondering if, instead of 
modifying exe_file and adding an interpreter file, you'd want to leave 
exe_file alone and instead provide an easier way to obtain the 
interpreted file.

Can you maybe describe why modifying exe_file is desired (about which 
consumers are we worrying? ) and what exactly FEX does to handle that 
(how does it mask that?).

So a bit more background on the challenges without this change would be 
appreciated.

-- 
Cheers,

David / dhildenb