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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 3BBB1C15506 for ; Thu, 4 Mar 2021 00:14:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1BEB364F38 for ; Thu, 4 Mar 2021 00:14:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241039AbhCDAOH (ORCPT ); Wed, 3 Mar 2021 19:14:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:55732 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240186AbhCDABC (ORCPT ); Wed, 3 Mar 2021 19:01:02 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 787BC64FCA; Thu, 4 Mar 2021 00:00:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614816021; bh=KyhESCEyk95eJXUdX1QrZPaV6Phl+cBTOepbGY9cM04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jqmisaPsaTSFMUX24m82jvJiEBwyuBK+pqhsm6cZjGmUVbtDFx13Df1a+wYeiotU9 iXL3n+17rzt2AjtX7GyurgF9wyMMGYZXv7D9/mU48jPtmnf2Vsqv0a4ToUn2nkn9Nn YXPdobmdxSwtQoEwOag+TOzswHekWffY0EUFo13QB3ApnfoOSFVg4ZU3+jCC3LP3+3 UnChLsmNzNrWW9gpIAOliAwwVrMzhRKTQiKUbgFa1SNU+EYnXaeqVfmo+xO+iE0KG7 eD3I2/5ME2SbWMD9xayzZvmDpCVkw4z0EttQfm3gyZPw96Zz1r2kwHw8pBpzdbtrLq 6eK4qaCGdakpw== From: paulmck@kernel.org To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, Zhouyi Zhou , "Paul E . McKenney" Subject: [PATCH tip/core/rcu 03/10] rcu: Remove spurious instrumentation_end() in rcu_nmi_enter() Date: Wed, 3 Mar 2021 16:00:12 -0800 Message-Id: <20210304000019.22459-3-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20210303235958.GA22373@paulmck-ThinkPad-P72> References: <20210303235958.GA22373@paulmck-ThinkPad-P72> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zhouyi Zhou In rcu_nmi_enter(), there is an erroneous instrumentation_end() in the second branch of the "if" statement. Oddly enough, "objtool check -f vmlinux.o" fails to complain because it is unable to correctly cover all cases. Instead, objtool visits the third branch first, which marks following trace_rcu_dyntick() as visited. This commit therefore removes the spurious instrumentation_end(). Fixes: 04b25a495bd6 ("rcu: Mark rcu_nmi_enter() call to rcu_cleanup_after_idle() noinstr") Reported-by Neeraj Upadhyay Signed-off-by: Zhouyi Zhou Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index e62c2de..4d90f20 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1076,7 +1076,6 @@ noinstr void rcu_nmi_enter(void) } else if (!in_nmi()) { instrumentation_begin(); rcu_irq_enter_check_tick(); - instrumentation_end(); } else { instrumentation_begin(); } -- 2.9.5