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=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 0ACA0C43331 for ; Fri, 6 Sep 2019 15:18:51 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 D3E3B20650 for ; Fri, 6 Sep 2019 15:18:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="K8b0NvTI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D3E3B20650 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.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:Date: Message-ID:References:To:Subject:From:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=mbjE5hu8zyjRJGdiOfw8D9V1q6vvxRcrMYLW0iZgGmw=; b=K8b0NvTIMvK4xI NeKm0oJrJGmArOS9TEzoUFxDzDn/tpXiDAHX40jK+aB78HSVW9uKpTaSkd2NctLP8JiNIWMMWv7Fl 22HeU2N71ykfZnnisaOELVPDcCsDcRYMuK1uhIN+iGH5RV+h88I4hIDLGHxy24qPHyV4UJT/Y6W/V lsl6gf+zqftB3YTMtb+b3nuWmIx7moMQDfp5qhBQK23UKDN2rlSFiZKCGy1HvLWTxC4K8hZn6w7in Q5WJJ0xWpBZ+ziN3njTyvUoZ9uxSzyWvLsEAMgjwTwpnvyNz82sVrYD9wxWtnu63s+qIVDkbkmLlE dgJpTip1SHxNGvv5R+VA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i6G0d-0003cV-Sl; Fri, 06 Sep 2019 15:18:48 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i6Fzq-0002vo-4V; Fri, 06 Sep 2019 15:17:59 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9B9CE1596; Fri, 6 Sep 2019 08:17:57 -0700 (PDT) Received: from [10.1.196.105] (unknown [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0D1163F59C; Fri, 6 Sep 2019 08:17:54 -0700 (PDT) From: James Morse Subject: Re: [PATCH v3 05/17] arm64, hibernate: check pgd table allocation To: Pavel Tatashin References: <20190821183204.23576-1-pasha.tatashin@soleen.com> <20190821183204.23576-6-pasha.tatashin@soleen.com> Message-ID: Date: Fri, 6 Sep 2019 16:17:53 +0100 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190821183204.23576-6-pasha.tatashin@soleen.com> Content-Language: en-GB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190906_081758_282335_85959227 X-CRM114-Status: GOOD ( 14.54 ) 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: sashal@kernel.org, mark.rutland@arm.com, vladimir.murzin@arm.com, corbet@lwn.net, marc.zyngier@arm.com, catalin.marinas@arm.com, bhsharma@redhat.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, jmorris@namei.org, linux-mm@kvack.org, ebiederm@xmission.com, matthias.bgg@gmail.com, will@kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Pavel, On 21/08/2019 19:31, Pavel Tatashin wrote: > There is a bug in create_safe_exec_page(), when page table is allocated > it is not checked that table is allocated successfully: > > But it is dereferenced in: pgd_none(READ_ONCE(*pgdp)). If there is a bug, it shouldn't be fixed part way through a series. This makes it difficult to backport the fix. Please split this out as an independent patch with a 'Fixes:' tag for the commit that introduced the bug. > Another issue, So this patch does two things? That is rarely a good idea. Again, this makes it difficult to backport the fix. > is that phys_to_ttbr() uses an offset in page table instead > of pgd directly. If you were going to reuse this, that would be a bug. But because the only page that is being mapped, is mapped to PAGE_SIZE, all the top bits will be 0. The offset calls are boiler-plate. It doesn't look intentional, but its harmless. Please separate out the potential NULL-dereference bits so there is a clean stand-alone fix that can be sent to the stable trees. Thanks, James _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel