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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5BE81C2D0A8 for ; Wed, 23 Sep 2020 13:23:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 719A12311E for ; Wed, 23 Sep 2020 13:23:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 719A12311E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 6454C6B0003; Wed, 23 Sep 2020 09:23:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5F38F6B005A; Wed, 23 Sep 2020 09:23:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 508A26B005C; Wed, 23 Sep 2020 09:23:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0089.hostedemail.com [216.40.44.89]) by kanga.kvack.org (Postfix) with ESMTP id 386E46B0003 for ; Wed, 23 Sep 2020 09:23:11 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id D1E02181AEF07 for ; Wed, 23 Sep 2020 13:23:10 +0000 (UTC) X-FDA: 77294392140.04.rest33_210841d27156 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin04.hostedemail.com (Postfix) with ESMTP id A29D08009659; Wed, 23 Sep 2020 13:23:10 +0000 (UTC) X-HE-Tag: rest33_210841d27156 X-Filterd-Recvd-Size: 2748 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [195.92.253.2]) by imf37.hostedemail.com (Postfix) with ESMTP; Wed, 23 Sep 2020 13:23:09 +0000 (UTC) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kL4jW-004YbY-CV; Wed, 23 Sep 2020 13:22:54 +0000 Date: Wed, 23 Sep 2020 14:22:54 +0100 From: Al Viro To: Pavel Begunkov Cc: Arnd Bergmann , Andy Lutomirski , Christoph Hellwig , Andrew Morton , Jens Axboe , David Howells , linux-arm-kernel , X86 ML , LKML , "open list:MIPS" , Parisc List , linuxppc-dev , linux-s390 , sparclinux , linux-block , Linux SCSI List , Linux FS Devel , linux-aio , io-uring@vger.kernel.org, linux-arch , Linux-MM , Network Development , keyrings@vger.kernel.org, LSM List Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-ID: <20200923132254.GI3421308@ZenIV.linux.org.uk> References: <563138b5-7073-74bc-f0c5-b2bad6277e87@gmail.com> <486c92d0-0f2e-bd61-1ab8-302524af5e08@gmail.com> <91209170-dcb4-d9ee-afa0-a819f8877b86@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <91209170-dcb4-d9ee-afa0-a819f8877b86@gmail.com> 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 Wed, Sep 23, 2020 at 11:01:34AM +0300, Pavel Begunkov wrote: > > I'm not following why that would be considered a valid option, > > as that clearly breaks existing users that update from a 32-bit > > kernel to a 64-bit one. > > Do you mean users who move 32-bit binaries (without recompiling) to a > new x64 kernel? Does the kernel guarantees that to work? Yes. No further (printable) comments for now...