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=-11.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,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 8FB7BC04EB5 for ; Fri, 7 Feb 2020 14:37:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E73321741 for ; Fri, 7 Feb 2020 14:37:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727154AbgBGOhW (ORCPT ); Fri, 7 Feb 2020 09:37:22 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:40980 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726674AbgBGOhW (ORCPT ); Fri, 7 Feb 2020 09:37:22 -0500 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 1j04kw-0005HH-Sc; Fri, 07 Feb 2020 15:37:18 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 1D4CC1C1A0E; Fri, 7 Feb 2020 15:37:18 +0100 (CET) Date: Fri, 07 Feb 2020 14:37:17 -0000 From: "tip-bot2 for Paul E. McKenney" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: smp/urgent] smp/up: Make smp_call_function_single() match SMP semantics Cc: "Paul E. McKenney" , Thomas Gleixner , x86 , LKML In-Reply-To: <20200205143409.GA7021@paulmck-ThinkPad-P72> References: <20200205143409.GA7021@paulmck-ThinkPad-P72> MIME-Version: 1.0 Message-ID: <158108623779.411.17538736321432389803.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 smp/urgent branch of tip: Commit-ID: 1e474b28e78897d0d170fab3b28ba683149cb9ea Gitweb: https://git.kernel.org/tip/1e474b28e78897d0d170fab3b28ba683149cb9ea Author: Paul E. McKenney AuthorDate: Wed, 05 Feb 2020 06:34:09 -08:00 Committer: Thomas Gleixner CommitterDate: Fri, 07 Feb 2020 15:34:12 +01:00 smp/up: Make smp_call_function_single() match SMP semantics In CONFIG_SMP=y kernels, smp_call_function_single() returns -ENXIO when invoked for a non-existent CPU. In contrast, in CONFIG_SMP=n kernels, a splat is emitted and smp_call_function_single() otherwise silently ignores its "cpu" argument, instead pretending that the caller intended to have something happen on CPU 0. Given that there is now code that expects smp_call_function_single() to return an error if a bad CPU was specified, this difference in semantics needs to be addressed. Bring the semantics of the CONFIG_SMP=n version of smp_call_function_single() into alignment with its CONFIG_SMP=y counterpart. Signed-off-by: Paul E. McKenney Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200205143409.GA7021@paulmck-ThinkPad-P72 --- kernel/up.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/up.c b/kernel/up.c index 53144d0..c6f323d 100644 --- a/kernel/up.c +++ b/kernel/up.c @@ -14,7 +14,8 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info, { unsigned long flags; - WARN_ON(cpu != 0); + if (cpu != 0) + return -ENXIO; local_irq_save(flags); func(info);