From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFCFBC7EE25 for ; Thu, 8 Jun 2023 06:29:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234692AbjFHG3J (ORCPT ); Thu, 8 Jun 2023 02:29:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234391AbjFHG3H (ORCPT ); Thu, 8 Jun 2023 02:29:07 -0400 Received: from mail-ed1-f47.google.com (mail-ed1-f47.google.com [209.85.208.47]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1579C1FF3 for ; Wed, 7 Jun 2023 23:29:06 -0700 (PDT) Received: by mail-ed1-f47.google.com with SMTP id 4fb4d7f45d1cf-510d6b939bfso394121a12.0 for ; Wed, 07 Jun 2023 23:29:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686205744; x=1688797744; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=seSDBs2iSKzHixZsKT42rBb3Fve7AmQHnIoa9gvwdBE=; b=Bk+nSKVgyibd0bi0HrFmGY7dZ33LFmMjGTLfgjD2v7jGK8b86cFKGqNIUku/67Scuk BidoOCvBDy1oIdHL8FfI2bmu/s7VYiCCtSlreKd1XlCiuff5Pl34v1aeIa5EI4VDtbLq Lls+HonM6nl2H6x+OWOg69JBwLA28VfWppc8Z++1a/UjY7Qkb8J3QT5xzIjqNZpgEcqA XLyAwPPhl3xOdFTdqkLe1QgFOzzVEoQk9aopoV0Zy3l/pqvc5Cm1QJDYXEly9XW0ziiP +F9TCEqGrZ9vdJlBrYajB/Iu7oQoNPVw+ygDY8br+C5Y5Rz7NqlRP+AaHuVdSRTFtcX4 jskA== X-Gm-Message-State: AC+VfDyhIL0VehSY5u/OAYoGsTFsOeVsAwkp2RKJJ6BsropDtOatH+gL mLRfQnVygYGZuVX3RdTYv6A= X-Google-Smtp-Source: ACHHUZ6J4Jq+eaM+N/W547FDXtvrOnP9Wu+gVHBtzzvLUx6kLTGdoEJOaSN3MGv9NFEf4b/+LLMpbg== X-Received: by 2002:a05:6402:785:b0:50b:d76a:7904 with SMTP id d5-20020a056402078500b0050bd76a7904mr5764069edy.28.1686205744312; Wed, 07 Jun 2023 23:29:04 -0700 (PDT) Received: from [192.168.1.58] (185-219-167-24-static.vivo.cz. [185.219.167.24]) by smtp.gmail.com with ESMTPSA id w25-20020a056402129900b0051659c6d50csm164816edv.22.2023.06.07.23.29.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 07 Jun 2023 23:29:03 -0700 (PDT) Message-ID: <2a64981c-ee53-f146-32a4-e97d4c036259@kernel.org> Date: Thu, 8 Jun 2023 08:29:02 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.2 Subject: Re: [PATCH 3/3] x86: Disable running 32bit processes if ia32_disabled is passed Content-Language: en-US To: Thomas Gleixner , Andrew Cooper , Nikolay Borisov , x86@kernel.org Cc: linux-kernel@vger.kernel.org, mhocko@suse.com References: <20230607072936.3766231-1-nik.borisov@suse.com> <20230607072936.3766231-4-nik.borisov@suse.com> <87legvjxat.ffs@tglx> <80f2045b-f276-e127-8e46-87fb6994fb41@suse.com> <87fs73juwa.ffs@tglx> <87a5xbjpk2.ffs@tglx> <875d0ab7-4470-25e2-6c01-72e231aae515@citrix.com> <874jnjj5z2.ffs@tglx> <278d7231-ee27-602f-4ba7-45d45d6772b3@citrix.com> <871qimkdft.ffs@tglx> From: Jiri Slaby In-Reply-To: <871qimkdft.ffs@tglx> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08. 06. 23, 2:25, Thomas Gleixner wrote: >> For usecases where there ought not to be any 32bit code at all (and >> there absolutely are), it would be lovely if this could be enforced, >> rather than relying on blind hope that it doesn't happen. > > I think it's rather clear what needs to be done here to achieve that, > but that's completely orthogonal to the intent of the patch series in > question which aims to make CONFIG_IA32_EMULATION a boot time decision. Agreed. The original intent was only to disable the 32bit paths in the kernel. I.e. set CONFIG_IA32_EMULATION=n by a runtime switch. Then we came up with idea to disallow loading 32bit binaries to WARN people as the bins won't (mostly) work anyway. (We are/were aware this doesn't forbid running 32bit code.) But now, when we are doing that, I think we should disable 32 bits completely by the switch. I.e. don't provide 32bit segments and whatever. And make that clear and documented in the series. Because as it stands now, it's half-way. Agreed? This whole attempt served as a call for opinions which we got and which is perfect. thanks, -- js suse labs