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[209.85.219.173]) by smtp.gmail.com with ESMTPSA id y18-20020ac85f52000000b002ed08a7dc8dsm3030641qta.13.2022.04.21.00.00.13 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 Apr 2022 00:00:13 -0700 (PDT) Received: by mail-yb1-f173.google.com with SMTP id g14so3729780ybj.12 for ; Thu, 21 Apr 2022 00:00:13 -0700 (PDT) X-Received: by 2002:a5b:984:0:b0:63f:8c38:676c with SMTP id c4-20020a5b0984000000b0063f8c38676cmr23970174ybq.393.1650523990757; Wed, 20 Apr 2022 23:53:10 -0700 (PDT) MIME-Version: 1.0 References: <20220414091018.896737-1-niklas.cassel@wdc.com> <81788b56-5b15-7308-38c7-c7f2502c4e15@linux-m68k.org> <87levzzts4.fsf_-_@email.froward.int.ebiederm.org> <01b063d7-d5c2-8af0-ad90-ed6c069252c5@linux-m68k.org> In-Reply-To: <01b063d7-d5c2-8af0-ad90-ed6c069252c5@linux-m68k.org> From: Geert Uytterhoeven Date: Thu, 21 Apr 2022 08:52:59 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] binfmt_flat: Remove shared library support To: Greg Ungerer Cc: "Eric W. Biederman" , Kees Cook , Niklas Cassel , Damien Le Moal , Alexander Viro , Paul Walmsley , Palmer Dabbelt , Albert Ou , Mike Frysinger , "stable@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "linux-riscv@lists.infradead.org" , Linux-Arch , linux-m68k , Linux ARM , Linux-sh list , Yoshinori Sato , Rich Felker Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: AB3492001B X-Rspam-User: Authentication-Results: imf03.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf03.hostedemail.com: domain of geert.uytterhoeven@gmail.com designates 209.85.219.44 as permitted sender) smtp.mailfrom=geert.uytterhoeven@gmail.com X-Stat-Signature: zxhun1eq5r8nsua5uni7ruwt8hyj6mxb X-HE-Tag: 1650524412-507065 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Apr 21, 2022 at 1:53 AM Greg Ungerer wrote: > On 21/4/22 00:58, Eric W. Biederman wrote: > > In a recent discussion[1] it was reported that the binfmt_flat library > > support was only ever used on m68k and even on m68k has not been used > > in a very long time. > > > > The structure of binfmt_flat is different from all of the other binfmt > > implementations becasue of this shared library support and it made > > life and code review more effort when I refactored the code in fs/exec.c. > > > > Since in practice the code is dead remove the binfmt_flat shared libarary > > support and make maintenance of the code easier. > > > > [1] https://lkml.kernel.org/r/81788b56-5b15-7308-38c7-c7f2502c4e15@linux-m68k.org > > Signed-off-by: "Eric W. Biederman" > > --- > > > > Can the binfmt_flat folks please verify that the shared library support > > really isn't used? > > I can definitely confirm I don't use it on m68k. And I don't know of > anyone that has used it in many years. > > > > Was binfmt_flat being enabled on arm and sh the mistake it looks like? I think the question was intended to be Was *binfmt_flat_shared_flat* being enabled on arm and sh the mistake it looks like? > > > > arch/arm/configs/lpc18xx_defconfig | 1 - > > arch/arm/configs/mps2_defconfig | 1 - > > arch/arm/configs/stm32_defconfig | 1 - > > arch/arm/configs/vf610m4_defconfig | 1 - > > binfmt_flat works on ARM. I use it all the time. > According to those defconfigs those are all non-MMU systems, so > having binfmt_flat enabled makes some sense there. > > > > arch/sh/configs/rsk7201_defconfig | 1 - > > arch/sh/configs/rsk7203_defconfig | 1 - > > arch/sh/configs/se7206_defconfig | 1 - > > Those are all SH2 systems if I am reading the defconfigs correctly. > SH2 is non-MMU according to the Kconfig setup. So it makes sense that > binfmt_flat is enabled on those too. I've checked git history, and CONFIG_BINFMT_SHARED_FLAT was enabled in se7206_defconfig in a non-specific defconfig update, so no further info. The other two had it enabled since their introduction, so I guess they were just based on the former. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds