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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 27F55C433F5 for ; Fri, 7 Sep 2018 19:51:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB72720844 for ; Fri, 7 Sep 2018 19:51:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DB72720844 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 S1727043AbeIHAd6 (ORCPT ); Fri, 7 Sep 2018 20:33:58 -0400 Received: from mga17.intel.com ([192.55.52.151]:2878 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725987AbeIHAd5 (ORCPT ); Fri, 7 Sep 2018 20:33:57 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Sep 2018 12:51:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,343,1531810800"; d="scan'208";a="88584859" Received: from viggo.jf.intel.com (HELO localhost.localdomain) ([10.54.77.144]) by orsmga001.jf.intel.com with ESMTP; 07 Sep 2018 12:51:29 -0700 Subject: [RFC][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 From: Dave Hansen Date: Fri, 07 Sep 2018 12:48:58 -0700 References: <20180907194852.3C351B82@viggo.jf.intel.com> In-Reply-To: <20180907194852.3C351B82@viggo.jf.intel.com> Message-Id: <20180907194858.FD74A39F@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 --- 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 2018-09-07 11:21:47.182751900 -0700 +++ b/arch/x86/mm/fault.c 2018-09-07 11:21:47.185751900 -0700 @@ -1274,9 +1274,17 @@ void do_user_addr_space_fault(struct pt_ 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; _