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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 D6715C43331 for ; Fri, 27 Mar 2020 07:57:07 +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 A736020705 for ; Fri, 27 Mar 2020 07:57:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="lwHCMy2B"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="t9b1OtD3" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A736020705 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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: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=e4fnNTfklxgUbkYX+OswnVKdYx109Gh0JrPkfPN6GNk=; b=lwHCMy2BsHjLuT blUT/rsa5Hh+uHEoks9GrYVXnQtWsv5ewIcjX4gYyA1LjMINSa4YwCvbcY6uI3OWfPj8p6CDzvu5K LaIyeilESRMost0OJLKuf5CVGV0W60wHLHlUBvleo/GQdRoXod3nqTAFhxi18P6T+zhyVJufuLiBQ +Yaa+RFlIcg7XV6Q9eM5oRvxz1zlluTiT8LYQApcthWC5hsi9zcIULwVS0ra3g+VblknA4o8OQHwp /zxDQDV6oAyScdVV42UyXxoA6Ogs5zeLccRornd8ciwcLHfiXxyJZjzC1TTTlZ/wBZDBpn8J5t3Ju pf4pJEOovVHltiL79iHw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jHjrX-000326-5h; Fri, 27 Mar 2020 07:57:07 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jHjrT-00031b-5L for linux-arm-kernel@lists.infradead.org; Fri, 27 Mar 2020 07:57:04 +0000 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C48F720705; Fri, 27 Mar 2020 07:56:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585295821; bh=9BBoSkOWHW032cVKGTcrvJhhotZiT+ANj18ZoBrCpkg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=t9b1OtD3X/UpkIFwKYnNjPQq9u1VECA/E2qw4tC0xW2YLvb2ITdVJKQi+hPcKZKKd DBTPj/8X2RhhVYpBgOb+1eCUa/VljebF3l25VvGlJWsYWn91FENKSjzWGc8m1A3fg4 08biC9AumsRp46PYwk24V0nWqUobUrOFKRlJY6hU= Date: Fri, 27 Mar 2020 07:56:56 +0000 From: Will Deacon To: Catalin Marinas Subject: Re: [PATCH v2] arm64: Expose original FAR_EL1 value in sigcontext Message-ID: <20200327075655.GA32241@willie-the-truck> References: <20200312171755.177743-1-pcc@google.com> <20200325174001.234803-1-pcc@google.com> <20200326164538.GC26987@mbp> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200326164538.GC26987@mbp> 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-20200327_005703_231379_08864AC5 X-CRM114-Status: GOOD ( 15.43 ) 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: Andrey Konovalov , Kevin Brodsky , Kostya Serebryany , Evgenii Stepanov , Vincenzo Frascino , Peter Collingbourne , Linux ARM , Richard Henderson 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 On Thu, Mar 26, 2020 at 04:45:39PM +0000, Catalin Marinas wrote: > On Wed, Mar 25, 2020 at 10:40:01AM -0700, Peter Collingbourne wrote: > > The kernel currently clears the tag bits (i.e. bits 56-63) in the fault > > address exposed via siginfo.si_addr and sigcontext.fault_address. However, > > the tag bits may be needed by tools in order to accurately diagnose > > memory errors, such as HWASan [1] or future tools based on the Memory > > Tagging Extension (MTE). > > > > We should not stop clearing these bits in the existing fault address > > fields, because there may be existing userspace applications that are > > expecting the tag bits to be cleared. Instead, create a far_context in > > sigcontext (similar to the existing esr_context), and store the original > > value of FAR_EL1 (including the tag bits) there. > > > > [1] http://clang.llvm.org/docs/HardwareAssistedAddressSanitizerDesign.html > > > > Signed-off-by: Peter Collingbourne > > The patch looks fine. However, I wouldn't queue it for 5.7, it's too > close to the merging window and I'd like it to sit in linux-next for a > bit. Unless there are other comments, it looks fine to me for -rc8. You mean 5.8? I'm also a bit surprised not to see a docs update, given that we talk about the general lack of tags in siginfo_t towards the end of Documentation/arm64/tagged-pointers.rst Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel