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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 6A856C43382 for ; Fri, 28 Sep 2018 16:06:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 37F6D20684 for ; Fri, 28 Sep 2018 16:06:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 37F6D20684 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729474AbeI1Waj (ORCPT ); Fri, 28 Sep 2018 18:30:39 -0400 Received: from mga06.intel.com ([134.134.136.31]:3595 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726473AbeI1Wai (ORCPT ); Fri, 28 Sep 2018 18:30:38 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Sep 2018 09:06:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,315,1534834800"; d="scan'208";a="90428787" Received: from viggo.jf.intel.com (HELO localhost.localdomain) ([10.54.77.144]) by fmsmga002.fm.intel.com with ESMTP; 28 Sep 2018 09:06:08 -0700 Subject: [PATCH 4/8] x86/mm: add clarifying comments for user addr space To: linux-kernel@vger.kernel.org Cc: Dave Hansen , sean.j.christopherson@intel.com, peterz@infradead.org, tglx@linutronix.de, x86@kernel.org, luto@kernel.org, jannh@google.com From: Dave Hansen Date: Fri, 28 Sep 2018 09:02:25 -0700 References: <20180928160219.3402F0AA@viggo.jf.intel.com> In-Reply-To: <20180928160219.3402F0AA@viggo.jf.intel.com> Message-Id: <20180928160225.FFD44B8D@viggo.jf.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dave Hansen The SMAP and Reserved checking do not have nice comments. Add some to clarify and make it match everything else. Signed-off-by: Dave Hansen Cc: Sean Christopherson Cc: "Peter Zijlstra (Intel)" Cc: Thomas Gleixner Cc: x86@kernel.org Cc: Andy Lutomirski Cc: Jann Horn Cc: Sean Christopherson --- b/arch/x86/mm/fault.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff -puN arch/x86/mm/fault.c~pkeys-fault-warnings-02 arch/x86/mm/fault.c --- a/arch/x86/mm/fault.c~pkeys-fault-warnings-02 2018-09-27 10:17:22.992343568 -0700 +++ b/arch/x86/mm/fault.c 2018-09-27 10:17:22.996343568 -0700 @@ -1278,9 +1278,17 @@ void do_user_addr_fault(struct pt_regs * if (unlikely(kprobes_fault(regs))) return; + /* + * Reserved bits are never expected to be set on + * entries in the user portion of the page tables. + */ if (unlikely(hw_error_code & X86_PF_RSVD)) pgtable_bad(regs, hw_error_code, address); + /* + * Check for invalid kernel (supervisor) access to user + * pages in the user address space. + */ if (unlikely(smap_violation(hw_error_code, regs))) { bad_area_nosemaphore(regs, hw_error_code, address, NULL); return; _