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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 C34BBC433DF for ; Mon, 15 Jun 2020 22:31:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA1742074D for ; Mon, 15 Jun 2020 22:31:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726537AbgFOWbv (ORCPT ); Mon, 15 Jun 2020 18:31:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725843AbgFOWbu (ORCPT ); Mon, 15 Jun 2020 18:31:50 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93FD8C061A0E; Mon, 15 Jun 2020 15:31:50 -0700 (PDT) Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jkxdn-0006xU-Qh; Tue, 16 Jun 2020 00:31:44 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id C4A161C0085; Tue, 16 Jun 2020 00:31:42 +0200 (CEST) Date: Mon, 15 Jun 2020 22:31:42 -0000 From: "tip-bot2 for Peter Zijlstra" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/entry] x86/entry, bug: Comment the instrumentation_begin() usage for WARN() Cc: "Peter Zijlstra (Intel)" , x86 , LKML MIME-Version: 1.0 Message-ID: <159226030243.16989.1181108519578141239.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/entry branch of tip: Commit-ID: 8e8bb06d199a5aa7a534aa3b3fc0abbbc11ca438 Gitweb: https://git.kernel.org/tip/8e8bb06d199a5aa7a534aa3b3fc0abbbc11ca438 Author: Peter Zijlstra AuthorDate: Thu, 04 Jun 2020 11:17:40 +02:00 Committer: Peter Zijlstra CommitterDate: Mon, 15 Jun 2020 14:10:10 +02:00 x86/entry, bug: Comment the instrumentation_begin() usage for WARN() Explain the rationale for annotating WARN(), even though, strictly speaking printk() and friends are very much not safe in many of the places we put them. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/bug.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/include/asm/bug.h b/arch/x86/include/asm/bug.h index fb34ff6..0281895 100644 --- a/arch/x86/include/asm/bug.h +++ b/arch/x86/include/asm/bug.h @@ -75,6 +75,12 @@ do { \ unreachable(); \ } while (0) +/* + * This instrumentation_begin() is strictly speaking incorrect; but it + * suppresses the complaints from WARN()s in noinstr code. If such a WARN() + * were to trigger, we'd rather wreck the machine in an attempt to get the + * message out than not know about it. + */ #define __WARN_FLAGS(flags) \ do { \ instrumentation_begin(); \