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=-2.3 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 11B33C433E0 for ; Mon, 1 Jun 2020 09:14:50 +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 D020D206E2 for ; Mon, 1 Jun 2020 09:14:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QAF5pQZ0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D020D206E2 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=/LNDPaC6wzeJKed4Ci+MEdUiXqsOVRRIAyAzm9IAF/g=; b=QAF5pQZ0HG1VWe 2pihw2VyWXQW84UGSGo8dGL74TJejn9JFDgEAA5h3smO895ucQiwWNfOMVukUYBFCVx+t7svtader IrUhO3RR5bdEWgSR/h5/sOK0iLokTXtf6fSdCy7js50aHnj5iOMaX6frHCw3z8+dr5kfX673RyoGa C8QmkTV89h3ZseNnbH0bjg3D7V5+/+6pLYqLtjfDKVW42eJghKaG0+ObxETxIruMjM4JI1zkNv2E3 ZV5ccL6KD/dj2QTJPV4XGdtzJsaKtXx1ktX//qsV8xLCMgQ3GNgdeOnq2v6/0AJILjNSsICMibpyC vSNkUQBF5QgGXci4ySTQ==; 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 1jfgWv-0005Fa-En; Mon, 01 Jun 2020 09:14:49 +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 1jfgWs-0005En-Ap for linux-arm-kernel@lists.infradead.org; Mon, 01 Jun 2020 09:14:47 +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 CE0E21FB; Mon, 1 Jun 2020 02:14:44 -0700 (PDT) Received: from arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B12293F305; Mon, 1 Jun 2020 02:14:43 -0700 (PDT) Date: Mon, 1 Jun 2020 10:14:41 +0100 From: Dave Martin To: Keno Fischer Subject: Re: arm64: Register modification during syscall entry/exit stop Message-ID: <20200601091441.GW5031@arm.com> References: <20200519081551.GA9980@willie-the-truck> <20200520174149.GB27629@willie-the-truck> <20200527095528.GC11111@willie-the-truck> <20200527101929.GT5031@arm.com> <20200531093320.GA30204@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200601_021446_413602_1579CD51 X-CRM114-Status: GOOD ( 13.62 ) 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: Kyle Huey , Catalin Marinas , Linux Kernel Mailing List , Oleg Nesterov , Will Deacon , 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 On Sun, May 31, 2020 at 12:13:18PM -0400, Keno Fischer wrote: > > Keno -- are you planning to send out a patch? You previously spoke about > > implementing this using PTRACE_SETOPTIONS. > > Yes, I'll have a patch for you. Though I've come to the conclusion > that introducing a new regset is probably a better way to solve it. > We can then also expose orig_x0 at the same time and give it sane semantics > (there's some problems with the way it works currently - I'll write it up > together with the patch). I'd worry that having a new ptrace option would be useless bug- compatibility that is just going to bitrot. Can you explain why userspace would write a changed value for x7 but at the same time need that new to be thrown away? That sounds like a nonsensical thing for userspace to be doing. Cheers ---Dave _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel