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[209.85.208.173]) by smtp.gmail.com with ESMTPSA id w15sm660920lfd.95.2021.01.14.13.11.28 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 14 Jan 2021 13:11:29 -0800 (PST) Received: by mail-lj1-f173.google.com with SMTP id e7so8064113ljg.10 for ; Thu, 14 Jan 2021 13:11:28 -0800 (PST) X-Received: by 2002:a2e:6f17:: with SMTP id k23mr3837756ljc.411.1610658688595; Thu, 14 Jan 2021 13:11:28 -0800 (PST) MIME-Version: 1.0 References: <20210114175934.13070-1-will@kernel.org> <20210114175934.13070-5-will@kernel.org> <20210114190021.GB13135@willie-the-truck> <20210114194129.GA13314@willie-the-truck> In-Reply-To: <20210114194129.GA13314@willie-the-truck> From: Linus Torvalds Date: Thu, 14 Jan 2021 13:11:12 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC PATCH 4/8] mm: Separate fault info out of 'struct vm_fault' To: Will Deacon Cc: Nick Desaulniers , Linux Kernel Mailing List , Linux-MM , Linux ARM , Catalin Marinas , Jan Kara , Minchan Kim , Andrew Morton , "Kirill A . Shutemov" , Vinayak Menon , Hugh Dickins , Android Kernel Team Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 14, 2021 at 11:41 AM Will Deacon wrote: > > Sure enough, an arm64 defconfig builds perfectly alright with that change, > but it really shouldn't. I'm using clang 11.0.5, so I had another go with > GCC 9.2.1 and bang: Ok, looks like a clang bug, but a reasonably benign one. As long as we have sufficient coverage with gcc, we'll get error reporting in a timely manner for any new incorrect assignments, so I think we can do that constant anonymous struct even if it does mean that clang might let some bad cases through (I personally use gcc for build testing, and then clang for building my boot kernels, so I'd catch anything x86-64 allmodconfig in my build tests). And keeping it unnamed it would avoid a lot of noisy churn.. Linus 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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 82F8CC433E0 for ; Thu, 14 Jan 2021 21:11:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E959F23A3B for ; Thu, 14 Jan 2021 21:11:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E959F23A3B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2253F8D012B; Thu, 14 Jan 2021 16:11:34 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1D5B68D00F0; Thu, 14 Jan 2021 16:11:34 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0C47F8D012B; Thu, 14 Jan 2021 16:11:34 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0240.hostedemail.com [216.40.44.240]) by kanga.kvack.org (Postfix) with ESMTP id E880C8D00F0 for ; Thu, 14 Jan 2021 16:11:33 -0500 (EST) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id A7642181AEF31 for ; Thu, 14 Jan 2021 21:11:33 +0000 (UTC) X-FDA: 77705626866.18.loss08_2713d1c27529 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin18.hostedemail.com (Postfix) with ESMTP id 7C6C3100ED0F5 for ; Thu, 14 Jan 2021 21:11:33 +0000 (UTC) X-HE-Tag: loss08_2713d1c27529 X-Filterd-Recvd-Size: 4608 Received: from mail-lf1-f47.google.com (mail-lf1-f47.google.com [209.85.167.47]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Thu, 14 Jan 2021 21:11:33 +0000 (UTC) Received: by mail-lf1-f47.google.com with SMTP id s26so10068668lfc.8 for ; Thu, 14 Jan 2021 13:11:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=WZbWNTyCdiUNNLsPZb0uOA1PP4wQXROq46k1F1yytJw=; b=hen/WPHdi8Ht1TwC4P1EMLL6ADt5dJQsfTqWvojSe7pq3AVL/qQ0ufNnDDHPKoOGSi MYVjA4WG9Ppv9qI7iT3VnsqoeJWQREPL+moru7JOkpLRprs9K6Jiq0aRVURVoY5lfYVr jLkCnNQivZmx2z41fetvafqYYGLGeUBOPuu18= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WZbWNTyCdiUNNLsPZb0uOA1PP4wQXROq46k1F1yytJw=; b=YF7KZoxQURELu7Ag1lJLTXrdGkwABJW489iQlcqVhKqV+wj2Je+i3U0pLkUsofkz0c BMR4xoNKkgCrkb0BRzPqyORJLpzVJxNwC7GqBVZ3LDPO+zuSedVn2j1X2QoatHKDa2/p LTqNncTG6iufwjy4OAwrpDsoC9VUwMuLE9nOfoFsnNlZ8b7la9Xu9rXm25XInSelW9t+ PB4IDq3awlgocQnlWP/aiyphXSlbylD0KFxOCjhRd8fweAPa7d1VZ0Ab6Q3WRyOt8fLb diQszET0l7xRamuFNl9VlP6jEIEJ+zSlDJ3oIVm3+77LxNCeINgYXCsB0YlMAbEFvhDQ igeQ== X-Gm-Message-State: AOAM5327kK8J465/JsTmBbNtm/IkJsqSYC5UH2XqdxdZosoSwFT6zW/j lgUToxbzU/UhfsfyozH2mkwcIxRfi3UTYw== X-Google-Smtp-Source: ABdhPJx01e2RzTbft0f0Hu1QmmbK1jzUaZZ4lAYGuYdNlAzrY3gtJHMcY6sM23a0l+kzaU+129HWvg== X-Received: by 2002:a19:8451:: with SMTP id g78mr3786787lfd.402.1610658691011; Thu, 14 Jan 2021 13:11:31 -0800 (PST) Received: from mail-lj1-f173.google.com (mail-lj1-f173.google.com. [209.85.208.173]) by smtp.gmail.com with ESMTPSA id v10sm571978lji.130.2021.01.14.13.11.28 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 14 Jan 2021 13:11:29 -0800 (PST) Received: by mail-lj1-f173.google.com with SMTP id n8so8082849ljg.3 for ; Thu, 14 Jan 2021 13:11:28 -0800 (PST) X-Received: by 2002:a2e:6f17:: with SMTP id k23mr3837756ljc.411.1610658688595; Thu, 14 Jan 2021 13:11:28 -0800 (PST) MIME-Version: 1.0 References: <20210114175934.13070-1-will@kernel.org> <20210114175934.13070-5-will@kernel.org> <20210114190021.GB13135@willie-the-truck> <20210114194129.GA13314@willie-the-truck> In-Reply-To: <20210114194129.GA13314@willie-the-truck> From: Linus Torvalds Date: Thu, 14 Jan 2021 13:11:12 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC PATCH 4/8] mm: Separate fault info out of 'struct vm_fault' To: Will Deacon Cc: Nick Desaulniers , Linux Kernel Mailing List , Linux-MM , Linux ARM , Catalin Marinas , Jan Kara , Minchan Kim , Andrew Morton , "Kirill A . Shutemov" , Vinayak Menon , Hugh Dickins , Android Kernel Team Content-Type: text/plain; charset="UTF-8" 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, Jan 14, 2021 at 11:41 AM Will Deacon wrote: > > Sure enough, an arm64 defconfig builds perfectly alright with that change, > but it really shouldn't. I'm using clang 11.0.5, so I had another go with > GCC 9.2.1 and bang: Ok, looks like a clang bug, but a reasonably benign one. As long as we have sufficient coverage with gcc, we'll get error reporting in a timely manner for any new incorrect assignments, so I think we can do that constant anonymous struct even if it does mean that clang might let some bad cases through (I personally use gcc for build testing, and then clang for building my boot kernels, so I'd catch anything x86-64 allmodconfig in my build tests). And keeping it unnamed it would avoid a lot of noisy churn.. Linus 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=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 39ADBC433DB for ; Thu, 14 Jan 2021 21:12:56 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CC51B23436 for ; Thu, 14 Jan 2021 21:12:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC51B23436 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From:In-Reply-To: References:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Jl4LrdoL37JV1xzbeTLuL+WX/zKqu/8zOesOSF60x8I=; b=CBE52ChYYPf3ZRYzbxVdEQXC/ Qy5HUS8g4AfIfNimY7UZK+ATdJaXj8mAYsNbJFSD+CX9ESociQaNup1iOCOnBS5a+hPGLUVvw2X5S WuLgo5y04fCmRdK03UwNxCV929iNFmijqojpAEFjnKx9Zn0D268ZlOdh4kuQHUNgHTEak4bnLtaud 5ogisIUlju6kaCvf68v4oTJCYxeKdr2YIpWxNoeehdVIZFe7Nl9huK0SsFWCkVGznLhU/NlEbgcrc J/We/E8PiFlTBFY63QTB8FXfG+7pbpfz2wgBW9/xVnf0nuHG2hy4EwsWjvHZhLH1XD7N4mIZuMZwk vRMDjvT+A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l09u3-0003iR-DY; Thu, 14 Jan 2021 21:11:35 +0000 Received: from mail-lf1-x132.google.com ([2a00:1450:4864:20::132]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l09u0-0003hr-Sp for linux-arm-kernel@lists.infradead.org; Thu, 14 Jan 2021 21:11:33 +0000 Received: by mail-lf1-x132.google.com with SMTP id o17so10110629lfg.4 for ; Thu, 14 Jan 2021 13:11:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=WZbWNTyCdiUNNLsPZb0uOA1PP4wQXROq46k1F1yytJw=; b=hen/WPHdi8Ht1TwC4P1EMLL6ADt5dJQsfTqWvojSe7pq3AVL/qQ0ufNnDDHPKoOGSi MYVjA4WG9Ppv9qI7iT3VnsqoeJWQREPL+moru7JOkpLRprs9K6Jiq0aRVURVoY5lfYVr jLkCnNQivZmx2z41fetvafqYYGLGeUBOPuu18= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WZbWNTyCdiUNNLsPZb0uOA1PP4wQXROq46k1F1yytJw=; b=P759yFrshVAu+Iw7RoHvUmARVhnvKjrjOj06MzdSjP7fQm80tV4SkfMPFBwgXrcW/3 E56cBaDcNgvipJrCRo+1cCdIBfcHlv8eliS40SHCsS7iPO+zSi5KkRZ9dYfHRke8Pnv0 Ro+3j9ayfT1O9DY8bRqV6oSzalhJvuRzjqDI6ZELlY/uEKgS+i2idFjrz04J3KEU476X Dqm/a7RPi28zon/hOwnpgmS2k6x3vN70BHg92nl0uyJB5ARkZRMxp/A4OPp4ifqi8wqS uWNwAKlfq7YiW/1HHxs1UKrkHdEgzm+1zqH7ecB5OH4zYwC855Tg8iOuRHPX4EwROxRT GR/Q== X-Gm-Message-State: AOAM533jtL9EJwPpMyOcJIPP1sdB6y01w8NcXK65zwTPTO3EKSr9Ueoy 9oBrd+/oGRhcEszXxe7cWRDCllTf2Bz1sQ== X-Google-Smtp-Source: ABdhPJxRvBo83o7jiQe2Dpr+E3atZQzu61VH6+6maW+s7MoDXdyINDElhCPAuJHBh48O/X09l8Uacw== X-Received: by 2002:ac2:46d4:: with SMTP id p20mr4047391lfo.299.1610658690945; Thu, 14 Jan 2021 13:11:30 -0800 (PST) Received: from mail-lj1-f173.google.com (mail-lj1-f173.google.com. [209.85.208.173]) by smtp.gmail.com with ESMTPSA id q190sm568749ljb.8.2021.01.14.13.11.28 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 14 Jan 2021 13:11:29 -0800 (PST) Received: by mail-lj1-f173.google.com with SMTP id b10so8066842ljp.6 for ; Thu, 14 Jan 2021 13:11:28 -0800 (PST) X-Received: by 2002:a2e:6f17:: with SMTP id k23mr3837756ljc.411.1610658688595; Thu, 14 Jan 2021 13:11:28 -0800 (PST) MIME-Version: 1.0 References: <20210114175934.13070-1-will@kernel.org> <20210114175934.13070-5-will@kernel.org> <20210114190021.GB13135@willie-the-truck> <20210114194129.GA13314@willie-the-truck> In-Reply-To: <20210114194129.GA13314@willie-the-truck> From: Linus Torvalds Date: Thu, 14 Jan 2021 13:11:12 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC PATCH 4/8] mm: Separate fault info out of 'struct vm_fault' To: Will Deacon X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210114_161133_049570_3FE36EF9 X-CRM114-Status: GOOD ( 11.75 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jan Kara , Minchan Kim , Catalin Marinas , Nick Desaulniers , Linux Kernel Mailing List , Linux-MM , Vinayak Menon , Hugh Dickins , "Kirill A . Shutemov" , Andrew Morton , Android Kernel Team , Linux ARM Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jan 14, 2021 at 11:41 AM Will Deacon wrote: > > Sure enough, an arm64 defconfig builds perfectly alright with that change, > but it really shouldn't. I'm using clang 11.0.5, so I had another go with > GCC 9.2.1 and bang: Ok, looks like a clang bug, but a reasonably benign one. As long as we have sufficient coverage with gcc, we'll get error reporting in a timely manner for any new incorrect assignments, so I think we can do that constant anonymous struct even if it does mean that clang might let some bad cases through (I personally use gcc for build testing, and then clang for building my boot kernels, so I'd catch anything x86-64 allmodconfig in my build tests). And keeping it unnamed it would avoid a lot of noisy churn.. Linus _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel