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=-5.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 AEC22C2D0EC for ; Thu, 26 Mar 2020 16:45:51 +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 817B72073E for ; Thu, 26 Mar 2020 16:45:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="rSpVRXWu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 817B72073E 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=Y7WGdUEgkilBlr365DfosSuuQJ6B0G/DzmM8DpBqsmQ=; b=rSpVRXWuPYy1Lg 8ed9pH3uPlUKOtgBw1XtJahRrxd9kILiXllgCHICWR4DWQt0Z9FjcClQMJdGqHQ96t0RWR3Mr2vCy FLCaUJj1XIBbQDOut2b3EEVUv2LutLi6UowOqpaJWqaSMMfGH1/s8y5dWOik5s9/k21/CKnt94k8W bjCSsPyZzH4+ScNszXwdmL53/cZtyatqR4ZHq2GwCFZUTgfOg32VjRQ4tTjRhbUVI/Fhh4Azce3KA lQZTjV8zcCmohpI6wfLr0fFwYeHKE2+52+dsr29zize7uIvIFbFuxvq5X5wfBoG7lIsF3JlhO+D/i WXHsCB+vDNy+LOg60CKg==; 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 1jHVde-0007gB-2V; Thu, 26 Mar 2020 16:45:50 +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 1jHVda-0007fj-1I for linux-arm-kernel@lists.infradead.org; Thu, 26 Mar 2020 16:45:47 +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 B25747FA; Thu, 26 Mar 2020 09:45:43 -0700 (PDT) Received: from mbp (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6A38F3F71E; Thu, 26 Mar 2020 09:45:42 -0700 (PDT) Date: Thu, 26 Mar 2020 16:45:39 +0000 From: Catalin Marinas To: Peter Collingbourne Subject: Re: [PATCH v2] arm64: Expose original FAR_EL1 value in sigcontext Message-ID: <20200326164538.GC26987@mbp> References: <20200312171755.177743-1-pcc@google.com> <20200325174001.234803-1-pcc@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200325174001.234803-1-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-20200326_094546_121386_6B77AB6A X-CRM114-Status: GOOD ( 12.02 ) 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 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. Reviewed-by: Catalin Marinas Thanks. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel