Received: by 2002:ac0:a5a6:0:0:0:0:0 with SMTP id m35-v6csp511094imm; Thu, 30 Aug 2018 04:43:19 -0700 (PDT) X-Google-Smtp-Source: ANB0VdaCGRkqo8zBMjQYHaO+9/a1jkkHgTmpiLJ2MxjRGp9Nkf/WmPVO23G5ZxHgHGoYmgU01iJu X-Received: by 2002:a17:902:981:: with SMTP id 1-v6mr5003112pln.60.1535629399334; Thu, 30 Aug 2018 04:43:19 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1535629399; cv=none; d=google.com; s=arc-20160816; b=hdsGQH+MG2xPFHy0OO3RsCkOes/DfABGSbyKUbS8BxMXBJtJ0PVJGknZsYJhN3WPz2 6+BMGbrY4Kmxv7C4BcZykxlXJZuhqwqxsKmB5DYgIY4ybOZlYu+NijKUjscWQn+sG2oa BSwU7Hvc6SCvBdhGaHkk3qjagNrXxbXHxziNq9QOVkJDVqMgIakrlwDL3IFWOobkScLB f4fybyoT6KAg0mTs1/PVrjuCL2D49fLh/OG5ZQiMBHGFpduQ5BMW0Oxo5n5XsU6DBIcV BNSssqVegVzpynW9yTQ+9cAfAXSXAUyZJcZ8tPlJsbSxGs+CuHj7BCRFH+o736bCYi0v UeIg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:arc-authentication-results; bh=W/jdbb2Vq3Kiym03/gav3BOUvcnL67E9+cfyfM7MhIU=; b=RAcgygi9XUqYE3V6CU91C3DmCMam87Caq4T4pGdza1D4YKywREuICiigvc8xRsd1iv pj6REAr9cgsuPOJmkAHDrOCR3aojWFAKZpdIlk+nPeAuZnFVngGhlADVaWSVgk2sGf6v JsFUYcZ+EMOcy/TinuLUkVdBkfSvZQVCgqkkYz+I2vs+KF1Lx7ojKR+I4OHE8y9satC8 yig5SylIg0VJtmTKlaz+iXcpTv8zltmfQyfxYjPRVXyO+MvXgeB+ONrx6s/ki3MQcxJa Gkp9dgKVreG1FAOA2WKwjbbnu2MX4hiK7Y0gHoWK3NXvKfBsgTDYkkTK143DWkHbhdDR Sm0Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b="DMD4I/SS"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id l185-v6si6568322pfl.134.2018.08.30.04.43.00; Thu, 30 Aug 2018 04:43:19 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b="DMD4I/SS"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728682AbeH3PnT (ORCPT + 99 others); Thu, 30 Aug 2018 11:43:19 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:39796 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728227AbeH3PnS (ORCPT ); Thu, 30 Aug 2018 11:43:18 -0400 Received: by mail-wm0-f67.google.com with SMTP id q8-v6so1681562wmq.4 for ; Thu, 30 Aug 2018 04:41:34 -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 :mime-version:content-transfer-encoding; bh=W/jdbb2Vq3Kiym03/gav3BOUvcnL67E9+cfyfM7MhIU=; b=DMD4I/SS8lJ+d3U1+HP9Yl6kLLZHPhvAdJS/JxxXCHjmDxUF/UgLbg2LpoqOkcwLuR wQQPHq4FCtWNS5xr7a3yBgBLJiWBX59b39kyQUx1OqIRTZZTjyRpftdyJmGkxbABZFU6 5KDwphISdpfEXbTOa+4UH4EiTU/0Wi30p9H0GhSfdYr6ze+w3YzNJGGCjrGlYOzyxLmh iWSjewMZmvPQ1GwgRIhyGXsGTzAm8HlL91OxzULxqV+6QAR/5fdqnSyQQBmOZsTukWgi 9+fmCsSQzqxxTagM+2Wx2wT5yLGsY3A4DZXaZsUTAtgiarABDJqijOFj2slq5uuV7G9d s3yw== 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:mime-version:content-transfer-encoding; bh=W/jdbb2Vq3Kiym03/gav3BOUvcnL67E9+cfyfM7MhIU=; b=getfZdZobzOeEWd1u56V4YJzU4SQVEKKif/HSGhgfz8QIqkbxCUvj1czrHDg659FX4 4bGEzEk8uyrcV5c0Ul+FqM9nOca1MfoPGzGJpOqageo+ezwJ5O5XESNxI2/oDnMm2/JI yUFoKsXJeyvjthz7/ZqZIuzXlKL3A4LiwGSEAZ2q8o64c5hPJesGH2stopIe8m0jL0Zk IVmL9r0rDBonY3hHlcYMcPu0wZO8i79Pur01DXEZkRa9Vrhfa3ss9Dy1qJ60pZAkxrf9 Ci6q8urf7nVoA0NplMx/Qe8v5QwMs8DjxGPbPiuP8jQBh+GAJMIMIarRY8wSQGoVHSm0 erGA== X-Gm-Message-State: APzg51A9sY6Ue1cnh9ZKNin/8JPe06JJmwwcs7nnIew/eSONiLvusyGr OwfVHvVnHK8lhTYog3gNRvQMgA== X-Received: by 2002:a1c:e54:: with SMTP id 81-v6mr1614151wmo.84.1535629293894; Thu, 30 Aug 2018 04:41:33 -0700 (PDT) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:84be:a42a:826d:c530]) by smtp.gmail.com with ESMTPSA id z184-v6sm2175218wmz.0.2018.08.30.04.41.32 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 30 Aug 2018 04:41:33 -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" , Shuah Khan , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Chintan Pandya Subject: [PATCH v6 09/11] arm64: update Documentation/arm64/tagged-pointers.txt Date: Thu, 30 Aug 2018 13:41:14 +0200 Message-Id: <594756b2aa9fea948f4da3cd01ffa8a5acbc5805.1535629099.git.andreyknvl@google.com> X-Mailer: git-send-email 2.19.0.rc0.228.g281dcd1b4d0-goog In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 -- 2.19.0.rc0.228.g281dcd1b4d0-goog