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=-0.8 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 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 B70E5C2BA83 for ; Thu, 13 Feb 2020 11:24:05 +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 783DE2073C for ; Thu, 13 Feb 2020 11:24:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sTkeK06u" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 783DE2073C 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=4FeORELzv9+BfwO4W0yQVa60OctPBySDFQWwo89i864=; b=sTkeK06uIhWO9G AMBhv68R1j/wH8w3lvDGC3Vtosd9T4+wyUhms8npPPCcA1vEMe+g3+1SFkrkZBI20O+0sokc53Lij VjbICsrJFWZ1BPx3fAsGqKGConVIXvVAcsKXswmzjRMcida9/w8S3Lj2VyrCsj504l8soJIng3/AQ seKwEHFoUDvOGCkdyOZIed622Rt2BN5mzSQR+lwObEJQM+KxzbEsApLkuRFZBv6ZnIkFNCxz+dkID EhcI5pb83GwZanbjdhaytoO9p707EMbMOiLnfdM5XRgLvV/oIEjWSoivHWfP+Ql6WZWmW9txTLfEV 0h0VWBQbMRynOGH9dhUA==; 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 1j2Cb6-0006Qa-Dv; Thu, 13 Feb 2020 11:23:56 +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 1j2Cb2-0006Pv-UG for linux-arm-kernel@lists.infradead.org; Thu, 13 Feb 2020 11:23:54 +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 2FE651FB; Thu, 13 Feb 2020 03:23:50 -0800 (PST) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.71]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6ACBA3F6CF; Thu, 13 Feb 2020 03:23:48 -0800 (PST) Date: Thu, 13 Feb 2020 11:23:46 +0000 From: Catalin Marinas To: Peter Collingbourne Subject: Re: [PATCH 00/22] arm64: Memory Tagging Extension user-space support Message-ID: <20200213112346.GA639258@arrakis.emea.arm.com> References: <20191211184027.20130-1-catalin.marinas@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200213_032353_020015_F7AC80A0 X-CRM114-Status: GOOD ( 14.76 ) 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: linux-arch@vger.kernel.org, Richard Earnshaw , Kostya Kortchinsky , Kostya Serebryany , Szabolcs Nagy , Marc Zyngier , Kevin Brodsky , linux-mm@kvack.org, Evgenii Stepanov , Andrey Konovalov , Vincenzo Frascino , Will Deacon , Linux ARM 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, Dec 13, 2019 at 10:05:10AM -0800, Peter Collingbourne wrote: > On Wed, Dec 11, 2019 at 10:40 AM Catalin Marinas > wrote: > > This series proposes the initial user-space support for the ARMv8.5 > > Memory Tagging Extension [1]. > > Thanks for sending out this series. I have been testing it on Android > with the FVP model and my in-development scudo changes that add memory > tagging support [1], and have not noticed any problems so far. Thanks for the comments so far and the testing. I'll post a v2 next week. > > - Clarify whether mmap(tagged_addr, PROT_MTE) pre-tags the memory with > > the tag given in the tagged_addr hint. Strong justification is > > required for this as it would force arm64 to disable the zero page. > > We would like to use this feature in scudo to tag large (>128KB on > Android) allocations, which are currently allocated via mmap rather > than from an allocation pool. Otherwise we would need to pay the cost > (perf and RSS) of faulting all of their pages at allocation time > instead of on demand, if we want to tag them. Would the default tag of 0 be sufficient here? We disable match-all for user-space already, so 0 is not a wildcard. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel