From patchwork Tue Jul 10 22:26:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu-cheng Yu X-Patchwork-Id: 10518215 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 E20326032A for ; Tue, 10 Jul 2018 22:33:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D32F22623D for ; Tue, 10 Jul 2018 22:33:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C73D028F39; Tue, 10 Jul 2018 22:33:14 +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, MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5C8972623D for ; Tue, 10 Jul 2018 22:33:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 476EE6B0290; Tue, 10 Jul 2018 18:33:13 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 44C626B0292; Tue, 10 Jul 2018 18:33:13 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 364C96B0293; Tue, 10 Jul 2018 18:33:13 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-pl0-f69.google.com (mail-pl0-f69.google.com [209.85.160.69]) by kanga.kvack.org (Postfix) with ESMTP id E7BB36B0292 for ; Tue, 10 Jul 2018 18:33:12 -0400 (EDT) Received: by mail-pl0-f69.google.com with SMTP id w1-v6so13258285plq.8 for ; Tue, 10 Jul 2018 15:33:12 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:from:to:cc :subject:date:message-id:in-reply-to:references; bh=vsWbAJ9dwtrANSA+1mry1OkwYd4ERwB0LycaMYYnhOk=; b=V/mchEvi8ceM0KBdy2aXch0d7uN2PB2++neOcKZu06WV94mtw6x6tuoSBQiRVDIRjA EFjyBoJYLwdALoXth3AchmZp8z3vXlAzBFknRmyL63TAJR0/2VvDn+1Qxl6FxZWQU55F ulhEfRvb0z3w21laPGFEHFT6NmHXrGBLsrioZI9IOhRlOMOz7KOFCDRR+598OZvZ8ltb YXPlESTOfMZULgEl8QH06ChkOnFu3sKE56PkocXXygIsX1YXX8ktabaMgOY23dsQIMl7 DnLDvzKiEBG8gRS6PXw/9AZ+QH26E0+XmIwzVQgN8XY/W4lWwuXxv7YfbN53tXosFmXm SMUw== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of yu-cheng.yu@intel.com designates 192.55.52.93 as permitted sender) smtp.mailfrom=yu-cheng.yu@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Gm-Message-State: APt69E0RUx3O83BCz7F3GLWgxCZ4EcQ9+KrsCfzIqDuNX/P8TryoE69u fzDX3/Z56izpTQ8hD37O+6VOflUEYDaZdh25GFJaDK8o9PjILtRAsQ5tXYBxEMhqrwiwbRGIx+t iBMS6TnbS1E0+ytFI7pQSIQA5tndMGUzMZKByFSeDM3KYhqpfX2e8HLsiyzIEo7+pEQ== X-Received: by 2002:a63:b047:: with SMTP id z7-v6mr24534218pgo.335.1531261992589; Tue, 10 Jul 2018 15:33:12 -0700 (PDT) X-Google-Smtp-Source: AAOMgpeoJXduqVXQphmqkb2xdH6saDnQpPXF9fNQ9TtHH1g/Gb3YriGErCQrlwz2aAoaQ034qwLs X-Received: by 2002:a63:b047:: with SMTP id z7-v6mr24529155pgo.335.1531261873308; Tue, 10 Jul 2018 15:31:13 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1531261873; cv=none; d=google.com; s=arc-20160816; b=ar8OLzPn+VApW+Oho8InBhPIDBSMBPt/b/mUIaUDQ7/lO5++0Xx4TP5zkPFRxXs2ok iM3VYnnjt5WXE9y44oG+6jVdp/o9eOV4/GoJWqGmEnokxyGxToZEm/V7CnRdLVnY23sp TN5J9/XNvT8Ip2x6Y5AJtvnMnNJl/8VpV0EchAMkja4jvqB8z8HUV8UWUtRgE55EgQf0 0QqS/vlDIRvtvvaFeYbOFS7rvSYqid34SNQ7UNmrWcxafgk7dvQ1j89Ju6wG9eqNpuKi +8DeDt3x9lUyi51Wjs9izGrVV9exNDuQVbkeNkhGMRGYzS55+f604hqBXoNeLjRonIII Nx4A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :arc-authentication-results; bh=vsWbAJ9dwtrANSA+1mry1OkwYd4ERwB0LycaMYYnhOk=; b=LgPCQ5HtRghe17N/sLZ6ngiIp5Q+fE/81ZxhLzaPhS/fYKdzEelkqcy4UKMDKnEyLK iiJ6ViNI77EDjZezWkyDQZYDFPbx5rXTwIrORr/4fxKOppOcx+l8Hx5eaaD5zoGG/bn6 3vur4S+lqxuQKRTD70a1aX7j7IYvZuZqetiY8DnvbhNa7Xn8oSGWUEx20EBSyldlJR5b Vebnh8g4SGuu77V/MhxcUIQo2y98idLzqNJ7pKs+dl0Z8fLHlyXkpMyFBtkg/n8i2mBM glWQpdvJaixI4byAv6wEXuAStQK2S4qnCPP4K/OHOedr123B3Iee75PvE+ZUEplDLhKc wrOQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of yu-cheng.yu@intel.com designates 192.55.52.93 as permitted sender) smtp.mailfrom=yu-cheng.yu@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTPS id q185-v6si17504162pga.322.2018.07.10.15.31.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 10 Jul 2018 15:31:13 -0700 (PDT) Received-SPF: pass (google.com: domain of yu-cheng.yu@intel.com designates 192.55.52.93 as permitted sender) client-ip=192.55.52.93; Authentication-Results: mx.google.com; spf=pass (google.com: domain of yu-cheng.yu@intel.com designates 192.55.52.93 as permitted sender) smtp.mailfrom=yu-cheng.yu@intel.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jul 2018 15:31:12 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,335,1526367600"; d="scan'208";a="70305407" Received: from 2b52.sc.intel.com ([143.183.136.52]) by fmsmga004.fm.intel.com with ESMTP; 10 Jul 2018 15:31:12 -0700 From: Yu-cheng Yu To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , "Ravi V. Shankar" , Vedvyas Shanbhogue Cc: Yu-cheng Yu Subject: [RFC PATCH v2 12/27] x86/mm: Shadow stack page fault error checking Date: Tue, 10 Jul 2018 15:26:24 -0700 Message-Id: <20180710222639.8241-13-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180710222639.8241-1-yu-cheng.yu@intel.com> References: <20180710222639.8241-1-yu-cheng.yu@intel.com> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: X-Virus-Scanned: ClamAV using ClamSMTP If a page fault is triggered by a shadow stack access (e.g. call/ret) or shadow stack management instructions (e.g. wrussq), then bit[6] of the page fault error code is set. In access_error(), we check if a shadow stack page fault is within a shadow stack memory area. Signed-off-by: Yu-cheng Yu --- arch/x86/include/asm/traps.h | 2 ++ arch/x86/mm/fault.c | 11 +++++++++++ 2 files changed, 13 insertions(+) diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 5196050ff3d5..58ea2f5722e9 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -157,6 +157,7 @@ enum { * bit 3 == 1: use of reserved bit detected * bit 4 == 1: fault was an instruction fetch * bit 5 == 1: protection keys block access + * bit 6 == 1: shadow stack access fault */ enum x86_pf_error_code { X86_PF_PROT = 1 << 0, @@ -165,5 +166,6 @@ enum x86_pf_error_code { X86_PF_RSVD = 1 << 3, X86_PF_INSTR = 1 << 4, X86_PF_PK = 1 << 5, + X86_PF_SHSTK = 1 << 6, }; #endif /* _ASM_X86_TRAPS_H */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 2aafa6ab6103..fcd5739151f9 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1163,6 +1163,17 @@ access_error(unsigned long error_code, struct vm_area_struct *vma) (error_code & X86_PF_INSTR), foreign)) return 1; + /* + * Verify X86_PF_SHSTK is within a shadow stack VMA. + * It is always an error if there is a shadow stack + * fault outside a shadow stack VMA. + */ + if (error_code & X86_PF_SHSTK) { + if (!(vma->vm_flags & VM_SHSTK)) + return 1; + return 0; + } + if (error_code & X86_PF_WRITE) { /* write, present and write, not present: */ if (unlikely(!(vma->vm_flags & VM_WRITE)))