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 E1D21C32750 for ; Fri, 2 Aug 2019 10:08:48 +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 B87212067D for ; Fri, 2 Aug 2019 10:08:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="S2mcoOXm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B87212067D 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=sh/qQ7zZRViUokY+f1qfCTmH9TmNYypSLONWlEMizRE=; b=S2mcoOXmZWrQEx l59wzhTRVHTJ73+LwbGsXhJWYk0MlsGtoH5hlzfi92KahOCXV3uI2cDjDUGD3EfUl/PGLGB8L+Elx KmqZcNTO0ROSsuIhj+q2Ph3DoMp1vTk1WjkATEumo+reRP/j2SGsyg++rstUa1uuzfha6zwK41Voz da8YBxT/mgMc2OWJL5W5c2f0qp+faH61ZwYrt5nyp4Lywd9u4WPqDjeLeIVMd6BusL3qnEC0alN+u 6SmM3AIisXwYMHOU+lVRgc0C3nbvaFlQpVd1UWPkzVMwoE2uaDDT3OTRmjq2gQFf1wlzHZ5W30dz5 PTmES0qpEgIAPFRuGQgQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1htUUS-0000Oq-BO; Fri, 02 Aug 2019 10:08:48 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1htUUO-0000Mm-Vc for linux-arm-kernel@lists.infradead.org; Fri, 02 Aug 2019 10:08:46 +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 2C9EB344; Fri, 2 Aug 2019 03:08:39 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B1D323F71F; Fri, 2 Aug 2019 03:08:37 -0700 (PDT) Date: Fri, 2 Aug 2019 11:08:35 +0100 From: Catalin Marinas To: Dave Hansen Subject: Re: [PATCH v6 1/2] arm64: Define Documentation/arm64/tagged-address-abi.rst Message-ID: <20190802100835.GA4175@arrakis.emea.arm.com> References: <20190725135044.24381-1-vincenzo.frascino@arm.com> <20190725135044.24381-2-vincenzo.frascino@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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-20190802_030845_062727_B207A2C6 X-CRM114-Status: GOOD ( 12.09 ) 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, linux-doc@vger.kernel.org, Szabolcs Nagy , Andrey Konovalov , Will Deacon , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Vincenzo Frascino , 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 Hi Dave, On Wed, Jul 31, 2019 at 09:43:46AM -0700, Dave Hansen wrote: > On 7/25/19 6:50 AM, Vincenzo Frascino wrote: > > With the relaxed ABI proposed through this document, it is now possible > > to pass tagged pointers to the syscalls, when these pointers are in > > memory ranges obtained by an anonymous (MAP_ANONYMOUS) mmap(). > > I don't see a lot of description of why this restriction is necessary. > What's the problem with supporting MAP_SHARED? We could support MAP_SHARED | MAP_ANONYMOUS (and based on some internal discussions, this would be fine with the hardware memory tagging as well). What we don't want in the ABI is to support file mmap() for top-byte-ignore (or MTE). If you see a use-case, please let us know. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel