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=-3.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_NEOMUTT 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 5D409C10F0E for ; Wed, 10 Apr 2019 03:37:46 +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 2894C206B6 for ; Wed, 10 Apr 2019 03:37:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="udaWXWth" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2894C206B6 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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=dYf6E5k13nOUVb4+B75+4gzbi4WJUKcG1MvbcbBjAsg=; b=udaWXWthpEWDyj TSEz1cruzC2yBPgNwGZHOR/8m86KQoXq5UTCFIceZcUEH1144ivqLdxa/zAyN+SONlBohZTktex5m Tj/WUwwVx79bdYyBC7s0Rk4Iqbj83tONPLI3QmPEWKJxYiHW2GY7du24xnV8uZ7lUz09ItXyCDvgj sZMvPfmTb/c542mhOKnAQCEp+Ja5dqPzKxiiYMWgy2BjHq3RPbVBuiW1nwD1wOarJzZBsPdy2cc9i 6Nsol1AY5aq0n7cGo92sozdO9LgWLlUgsoVZsbw3V+BnmylEEQ6Kl73isgEHCPtzgTSEYUpuA0lb6 VrW1LeBztSFIx8LBMg+A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hE43Q-0002GE-0y; Wed, 10 Apr 2019 03:37:40 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hE43N-0002Ft-9o for linux-arm-kernel@lists.infradead.org; Wed, 10 Apr 2019 03:37:38 +0000 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3143EF74B5; Wed, 10 Apr 2019 03:37:35 +0000 (UTC) Received: from treble (ovpn-120-231.rdu2.redhat.com [10.10.120.231]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F22E71001DC7; Wed, 10 Apr 2019 03:37:33 +0000 (UTC) Date: Tue, 9 Apr 2019 22:37:32 -0500 From: Josh Poimboeuf To: Ard Biesheuvel Subject: Re: [PATCH 0/6] objtool: Add support for Arm64 Message-ID: <20190410033732.ibtpnd36655afpfj@treble> References: <20190409135243.12424-1-raphael.gault@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 10 Apr 2019 03:37:35 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190409_203737_362355_DE87C596 X-CRM114-Status: GOOD ( 17.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Julien Thierry , Peter Zijlstra , Catalin Marinas , Will Deacon , Linux Kernel Mailing List , Raphael Gault , linux-arm-kernel 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 Tue, Apr 09, 2019 at 10:43:18AM -0700, Ard Biesheuvel wrote: > On Tue, 9 Apr 2019 at 06:53, Raphael Gault wrote: > > > > Hi, > > > > As of now, objtool only supports the x86_64 architecture but the > > groundwork has already been done in order to add support for other > > architecture without too much effort. > > > > This series of patches adds support for the arm64 architecture > > based on the Armv8.5 Architecture Reference Manual. > > > > I think it makes sense to clarify *why* we want this on arm64. Also, > we should identify things that objtool does today that maybe we don't > want on arm64, rather than buy into all of it by default. Agreed, the "why" should at least be in the cover letter. From my perspective, the "why" includes: - Live patching - objtool stack validation is the foundation for a reliable unwinder - ORC unwinder - benefits include presumed improved overall performance from disabling frame pointers, and the ability to unwind across interrupts and exceptions - PeterZ's new uaccess validation? -- Josh _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel