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=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 B4C70C54FCB for ; Wed, 22 Apr 2020 14:27:06 +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 670982082E for ; Wed, 22 Apr 2020 14:27:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="fADx4pvH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 670982082E 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: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=yVjvs8hCp19dEKgVA0ggvboXZ/E42hlUCrSgsrYAKSQ=; b=fADx4pvH//mOoc VNEWJWv2hSNLy7bRc3xf2LDXPHxLHEhjuagdSz2RPeIKVOI9s3NwqzzPLRjo5MUgwgADlI+PFm/NO 2tjNf/8trTYXL5svUnlmzMqizVx7FXDyfbVN2SHlItC7IaIM7+q4oYfyUX2WdN4Nk9+yp0CR7SRHu 9dpyptNPatH7vcMPxV7Cnr/0kJHjC8Xqu7jRBVwLsAIXyQGIElXnpM20wfrH2aYgPD6dIxA74gGyr Y6cPJEnJNpsxVoxwryo5JiwatkjprOGso3f03FpT8c9zTYSu/0ehHp3ITOvjibrYpy4DGiOnCkj04 FTK/gwhJRULo6LyWw8Vw==; 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 1jRGLB-0001uM-6b; Wed, 22 Apr 2020 14:27:05 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jRGK9-0000t6-3F for linux-arm-kernel@lists.infradead.org; Wed, 22 Apr 2020 14:26:03 +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 8A84E30E; Wed, 22 Apr 2020 07:26:00 -0700 (PDT) Received: from gaia (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4D0EB3F68F; Wed, 22 Apr 2020 07:25:59 -0700 (PDT) Date: Wed, 22 Apr 2020 15:25:53 +0100 From: Catalin Marinas To: Peter Collingbourne Subject: Re: [PATCH v3] arm64: Expose original FAR_EL1 value in sigcontext Message-ID: <20200422142552.GE3585@gaia> References: <20200325174001.234803-1-pcc@google.com> <20200327191915.257116-1-pcc@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200327191915.257116-1-pcc@google.com> 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-20200422_072601_218063_B5C4EE90 X-CRM114-Status: GOOD ( 11.31 ) 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 , Will Deacon , 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 Fri, Mar 27, 2020 at 12:19:15PM -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 Reviewed-by: Catalin Marinas _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel