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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_GIT 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 C2AE3C433E0 for ; Tue, 26 May 2020 01:42:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ADE78207DA for ; Tue, 26 May 2020 01:42:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388510AbgEZBmn (ORCPT ); Mon, 25 May 2020 21:42:43 -0400 Received: from out30-56.freemail.mail.aliyun.com ([115.124.30.56]:40486 "EHLO out30-56.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388442AbgEZBml (ORCPT ); Mon, 25 May 2020 21:42:41 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R431e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=laijs@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0TzfuFzj_1590457357; Received: from localhost(mailfrom:laijs@linux.alibaba.com fp:SMTPD_---0TzfuFzj_1590457357) by smtp.aliyun-inc.com(127.0.0.1); Tue, 26 May 2020 09:42:37 +0800 From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: Lai Jiangshan , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , x86@kernel.org, Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Alexandre Chartre , Changbin Du , Martin Molnar Subject: [RFC PATCH V2 6/7] x86/entry: is_debug_stack() don't check of DB1 stack Date: Tue, 26 May 2020 01:42:20 +0000 Message-Id: <20200526014221.2119-7-laijs@linux.alibaba.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200526014221.2119-1-laijs@linux.alibaba.com> References: <20200525152517.GY325280@hirez.programming.kicks-ass.net> <20200526014221.2119-1-laijs@linux.alibaba.com> 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 IST-shift code is removed from entry code, #DB will not at DB1 stack. So we remove the check of DB1 stack in is_debug_stack(). Cc: Andy Lutomirski Cc: Peter Zijlstra (Intel) Cc: Thomas Gleixner Cc: x86@kernel.org Signed-off-by: Lai Jiangshan --- arch/x86/kernel/nmi.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index 1c58454ac5fb..2f463f5880c6 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -500,15 +500,10 @@ static noinstr bool is_debug_stack(unsigned long addr) { struct cea_exception_stacks *cs = __this_cpu_read(cea_exception_stacks); unsigned long top = CEA_ESTACK_TOP(cs, DB); - unsigned long bot = CEA_ESTACK_BOT(cs, DB1); + unsigned long bot = CEA_ESTACK_BOT(cs, DB); if (__this_cpu_read(debug_stack_usage)) return true; - /* - * Note, this covers the guard page between DB and DB1 as well to - * avoid two checks. But by all means @addr can never point into - * the guard page. - */ return addr >= bot && addr < top; } #endif -- 2.20.1