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=-5.5 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,USER_AGENT_SANE_1 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 CA1B2C433E0 for ; Sun, 24 Jan 2021 16:20:34 +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 81D95229F0 for ; Sun, 24 Jan 2021 16:20:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81D95229F0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=armlinux.org.uk 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:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KIMw7J6F4VmevtL5heQOAk4Iu06pOv37V/JHmWP9aig=; b=HWnE8QyPpZGaswphjPu2fFBd1 S+oZBV+tlzG9IjxU/Iazm3edML9EO/1i//orbROQDhXdb+TJIsl83aU+UNc/AfS59PCgwto1TuLxJ fVtXiGAQR1TgTbsBXfYX96f1eWFPRPg5QlimtIaOWe6lSCh5DGXUpchfgOSxoEwZ2v4bmtK7iEEYe DBCuzumXVWeXlqUOqR9ZfC44VKcOCDc7Jls3gafvoJIgw5sdOe3ShnD/xxl0sUxOep4ucf6NbJBWk YUctARtMTwRhtGykXhQCtNqzRsqVyCliC9mtqkbbC2nRTGeklkofXmhN0PcfvfINfVGKOV8Um9hDI N9papD0VQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l3i64-0007ch-Gp; Sun, 24 Jan 2021 16:18:40 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l3i62-0007cE-B3 for linux-arm-kernel@lists.infradead.org; Sun, 24 Jan 2021 16:18:39 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=1pg4cdXlMAbdziEfbVcYi3dESSB+B9ekBEsbpRDzUgk=; b=1gOEegY/EeXexnN8VuEfVPwbl 90XE90qIZK2yikP3DmzXdOO80TAjnkJIbDMjZJmj36vIIT/rkbdFsk4oUExk245cePWfS931trn28 v9KzK7KROIhP3UOeWVNa1jT8g1AiqO/O82HzJBPscGaCl4j15J/XgGXLAZXJqP+JdDOLlDSiwB9Ym McvVaLqzVyAAfkYS/ZQKJrML3hP9DGpJewl3XxAfyQLku0T0Lv0snrTWJUlkzK9mdrDdxcJuOi4+f 1l5u1FZYzk04wursAXvGhD18FHKw1s4xMZP1ysW6Pn3NGvSGa2DcF1eAgjjHGX4i0UqCoLNUsGYB7 x/8/K99bg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:52180) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1l3i5x-0002V6-Lf; Sun, 24 Jan 2021 16:18:33 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1l3i5v-0001r1-K6; Sun, 24 Jan 2021 16:18:31 +0000 Date: Sun, 24 Jan 2021 16:18:31 +0000 From: Russell King - ARM Linux admin To: Ard Biesheuvel Subject: Re: [PATCH] ARM: decompressor: cover BSS in cache clean and reorder with MMU disable on v7 Message-ID: <20210124161831.GB1551@shell.armlinux.org.uk> References: <20210122152012.30075-1-ardb@kernel.org> <20210122161312.GS1551@shell.armlinux.org.uk> <20210124152127.GA1551@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210124_111838_442419_325F48AB X-CRM114-Status: GOOD ( 15.74 ) 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: Marc Zyngier , 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 Sun, Jan 24, 2021 at 04:45:14PM +0100, Ard Biesheuvel wrote: > Fair enough. I don't think we will ever be able to get to the bottom of this. DDI0406 does say that the data accesses will have a "strongly ordered" memory type, and that the unexpected cache hit behaviour is implementation defined. That leaves the door open for different behaviours at different cache levels in a SoC, especially when each cache level is designed by a different entity. So, without a greater understanding of how each level of cache operates and how they interact with each other, I don't think there's much hope of knowing definitely what is causing the observed behaviour. Hence, we agree. > So on the basis that this patch adds back a full cache > clean+invalidate that was inadvertently removed by my previous patch, > I think we should apply this patch. GIven that this change can be > traced back to commit 401b368caaecdce1cf8f05bab448172752230cb0, we > should probably include > > Fixes: 401b368caaec ("ARM: decompressor: switch to by-VA cache > maintenance for v7 cores") > > Are you on board with that? Yes, I think that's definitely the commit which introduced this bug. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel