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=-14.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 1C571C2D0A3 for ; Mon, 26 Oct 2020 11:17:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7F9821BE5 for ; Mon, 26 Oct 2020 11:17:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="c6ea4/xk"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="WnfT42vu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1772276AbgJZLR1 (ORCPT ); Mon, 26 Oct 2020 07:17:27 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:39210 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1771658AbgJZLR1 (ORCPT ); Mon, 26 Oct 2020 07:17:27 -0400 Date: Mon, 26 Oct 2020 11:17:22 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1603711044; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rNDs6bpZpK+4fqKA7xYj7+yLSIpGYZIr6FmNG8YWfaM=; b=c6ea4/xkOHuR5XuSya9Jy/sYvJRjr2Anx1mzgXmPqpeDEIYC4LetSJv4i0p8rU/rDCuIuq q9OA/nok6zj3NoeEtP5uAotYTym3aU7T1iXE0ipzOOZmsYISyY1DrTQUCPU2yqhiulGPiZ 2k5Ab0SYTmdV4jprbkcmrBTyzwRPJG9rzSbZUlrGDL+i/jxOx/e+vGQLxdiM/6hN7jUHgO HVJvOlKtgxOna+g68gfJr5ZrihUx3fWvriMxCaKjZQh6c0QMDKmUXHfjn2TtFFBhuEjooZ 9LTqw19TYSLphzU07vsYzaAA3UWZMe6l3d4/3AlaS0NzXvSOEIWQZPNwAMmRpg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1603711044; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rNDs6bpZpK+4fqKA7xYj7+yLSIpGYZIr6FmNG8YWfaM=; b=WnfT42vuMr+h7keSCV1GwxGX3SOecrZyHF4oFNubqad0xri25krNHFZ116LnHiTe8ghWfG 8OOHCuzE8vKfoFDw== From: "tip-bot2 for Zong Li" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: smp/urgent] stop_machine, rcu: Mark functions as notrace Cc: Zong Li , Thomas Gleixner , Atish Patra , Colin Ian King , "Steven Rostedt (VMware)" , "Paul E. McKenney" , stable@vger.kernel.org, x86 , LKML In-Reply-To: <20201021073839.43935-1-zong.li@sifive.com> References: <20201021073839.43935-1-zong.li@sifive.com> MIME-Version: 1.0 Message-ID: <160371104269.397.18106018255287440015.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit 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: 4230e2deaa484b385aa01d598b2aea8e7f2660a6 Gitweb: https://git.kernel.org/tip/4230e2deaa484b385aa01d598b2aea8e7f2660a6 Author: Zong Li AuthorDate: Wed, 21 Oct 2020 15:38:39 +08:00 Committer: Thomas Gleixner CommitterDate: Mon, 26 Oct 2020 12:12:27 +01:00 stop_machine, rcu: Mark functions as notrace Some architectures assume that the stopped CPUs don't make function calls to traceable functions when they are in the stopped state. See also commit cb9d7fd51d9f ("watchdog: Mark watchdog touch functions as notrace"). Violating this assumption causes kernel crashes when switching tracer on RISC-V. Mark rcu_momentary_dyntick_idle() and stop_machine_yield() notrace to prevent this. Fixes: 4ecf0a43e729 ("processor: get rid of cpu_relax_yield") Fixes: 366237e7b083 ("stop_machine: Provide RCU quiescent state in multi_cpu_stop()") Signed-off-by: Zong Li Signed-off-by: Thomas Gleixner Tested-by: Atish Patra Tested-by: Colin Ian King Acked-by: Steven Rostedt (VMware) Acked-by: Paul E. McKenney Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201021073839.43935-1-zong.li@sifive.com --- kernel/rcu/tree.c | 2 +- kernel/stop_machine.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 06895ef..2a52f42 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -409,7 +409,7 @@ bool rcu_eqs_special_set(int cpu) * * The caller must have disabled interrupts and must not be idle. */ -void rcu_momentary_dyntick_idle(void) +notrace void rcu_momentary_dyntick_idle(void) { int special; diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 865bb02..890b79c 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -178,7 +178,7 @@ static void ack_state(struct multi_stop_data *msdata) set_state(msdata, msdata->state + 1); } -void __weak stop_machine_yield(const struct cpumask *cpumask) +notrace void __weak stop_machine_yield(const struct cpumask *cpumask) { cpu_relax(); }