From patchwork Fri May 25 17:21:16 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10428145 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A7D326025B for ; Fri, 25 May 2018 17:37:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 99E1F2944E for ; Fri, 25 May 2018 17:37:47 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8E3D229764; Fri, 25 May 2018 17:37:47 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, DKIM_VALID, MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 117622944E for ; Fri, 25 May 2018 17:37:46 +0000 (UTC) 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:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=YdEv4QJZ3IOIYP7fwyKoaVXP6mLSxfGYDJvDA6X3m7k=; b=UBg+84IU0fUTwpX5N3yKiFFYQH 44ci3zNIdYJODLkuLA3fTGju99kJh9K3/NMHLGCGZOwJYB0BLf305h3KC4VybvKjhdXxNqnkAV8Dl GHi5TQH9gKWVwzqL5eRHHKlucOeEatpIMsaLrovjClL2gmQnaUMGENlnGBc7tTdeLnu91+RapOB21 8J8I5YAxuEdzuevAvJ1XuwKkh7EcyAndyjebFfZ6MUsf4gSc6eFrEctBLHnBUTGMYhKx829QGOBFY EoXPi/h6QY8oNlfBrHlflsskdMRAadpNYzBO+9iz1dSnFW7YwHp33IYoa7ZR5AVDtL9joI4DsyXyh 1h7S0Mbg==; 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 1fMGej-0001yJ-2g; Fri, 25 May 2018 17:37:33 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fMGcz-0000p0-0m for linux-arm-kernel@bombadil.infradead.org; Fri, 25 May 2018 17:35:45 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=References:In-Reply-To:Message-Id:Date: Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=lUjckscRelX9WqN/6FUbYAqpLfBHLKlTJUaLXI/81Ro=; b=L1AjOBJ2gB7fw5oaS3Mlq/EAe aHWn5k2XOq9Vo70jVPjHZ+z9HtiWWfqNt6EXPY5iY/7vs+0xMRro94B57G6POtMr/FWzIdYnR55JW j9VlvREz3A7XFDtv8t2/kysR36FsxDTDBwYB5vfVU62OYCEyhAq3dkTwSTfMtghl1PqZWyOh8cB/Z vbYrDC0wS6PpwnpUi/xf/5lnD2ckjpUPtQbg3Xgqlx7agokrd8tFj4025qPbftx5ixyv2LYk2P3IX WPBQEkIHksBRT36AUhCDVkRjDGsAF4FTbCkVlLG7WDBOt7Ep/4cuKCRA4baGmXyAZJv756L1waszs tGyNUAXkg==; Received: from mail-wm0-x241.google.com ([2a00:1450:400c:c09::241]) by casper.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fMGPM-0001HM-PV for linux-arm-kernel@lists.infradead.org; Fri, 25 May 2018 17:21:42 +0000 Received: by mail-wm0-x241.google.com with SMTP id l1-v6so16524299wmb.2 for ; Fri, 25 May 2018 10:21:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=lUjckscRelX9WqN/6FUbYAqpLfBHLKlTJUaLXI/81Ro=; b=D7wi0tvjGH19GsmXvbUDFetH80WmiT4sVJkuo+6TlZIwGVZF+aeiQcRS/zVmd8hsoX 4M3pb80fq+hrweG1H8PrClMPr0hbj9DeVne7liNqjwdm1xO7kVtHU0nQdAP7Xgve6OTz xZFS2mXfuYsHhxMX8ju2+atPxjD8N4oyk82Sqixng6MM03/1agy4pcjqY3JKOspVMF/R htHGVfzb1Jw7DL/BhVN9GlqBWuH5Z1XUHAf2OyyrFroQLSm31Vc7+wfISANc/L32WF66 VrBD4kL+p7jsiTrPilKzWRPii3adIgj/29FCdh1mhNf1eqQIOp9IMFnJyOutowNb5SYh wpQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=lUjckscRelX9WqN/6FUbYAqpLfBHLKlTJUaLXI/81Ro=; b=YuE5zYZjp/uniBxYhDybidOcabvI8ul2q0kIfGfMv3Ph9ac+7i9WGoDZUa8M/IuM1w AzGe7ECyqQ+ur+QqOA8tGyusaHP0sYQkq3jKt0oxPEE3yWz8DSSHWI3Qym8zaPDINuXu cxiiIiMrYbd04yibHcQAErb/ddUNKc4SvWFiPx1y8Be/hSYHdKMKfozm/s8WBoaJ8mB+ dTiymLcbediGSB85ywbYHCsjtiiHE1aJ13Mx9CxXUgOh8sJOFLrrO3Ie/fpYcRNLMUxT CwJ1LDOMGZ/NLfrVL7lhMZFKZeuGdQmwvYf1nPLhs1Z9KHsMAV/3oMIzfpYIkPNgWQFE tEhw== X-Gm-Message-State: ALKqPwdM36VN+NaK2JmmIRmhwNjEGOnYolDLGT9OddfIi2yOvLQwz1cr LAHH03zHhAceCupRNROdMZjo3w== X-Google-Smtp-Source: ADUXVKIm/vYg/sw9XUuIzvcDV9itQGOEJwWKLZCdqZ3j8/6iqc1AzAIteFMZ2ogZuXnxueZDrFqurQ== X-Received: by 2002:a1c:9249:: with SMTP id u70-v6mr2252097wmd.128.1527268888271; Fri, 25 May 2018 10:21:28 -0700 (PDT) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:84be:a42a:826d:c530]) by smtp.gmail.com with ESMTPSA id s5-v6sm26579964wra.48.2018.05.25.10.21.26 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 25 May 2018 10:21:27 -0700 (PDT) From: Andrey Konovalov To: Catalin Marinas , Will Deacon , Mark Rutland , Robin Murphy , Al Viro , Andrey Konovalov , Kees Cook , Kate Stewart , Greg Kroah-Hartman , Andrew Morton , Ingo Molnar , "Kirill A . Shutemov" , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 6/6] arm64: update Documentation/arm64/tagged-pointers.txt Date: Fri, 25 May 2018 19:21:16 +0200 Message-Id: X-Mailer: git-send-email 2.17.0.921.gf22659ad46-goog In-Reply-To: References: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180525_182140_833522_3F2B7DA7 X-CRM114-Status: GOOD ( 17.17 ) 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: Chintan Pandya , Jacob Bramley , Ruben Ayrapetyan , Lee Smith , Kostya Serebryany , Dmitry Vyukov , Ramana Radhakrishnan , Evgeniy Stepanov MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Add a note that work on passing tagged user pointers to the kernel via syscalls has started, but might not be complete yet. Signed-off-by: Andrey Konovalov --- Documentation/arm64/tagged-pointers.txt | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/Documentation/arm64/tagged-pointers.txt b/Documentation/arm64/tagged-pointers.txt index a25a99e82bb1..361481283f00 100644 --- a/Documentation/arm64/tagged-pointers.txt +++ b/Documentation/arm64/tagged-pointers.txt @@ -35,8 +35,9 @@ Using non-zero address tags in any of these locations may result in an error code being returned, a (fatal) signal being raised, or other modes of failure. -For these reasons, passing non-zero address tags to the kernel via -system calls is forbidden, and using a non-zero address tag for sp is +Some initial work for supporting non-zero address tags passed to the +kernel via system calls has been done, but the kernel doesn't provide +any guarantees at this point. Using a non-zero address tag for sp is strongly discouraged. Programs maintaining a frame pointer and frame records that use non-zero