From patchwork Wed May 12 14:46:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 436992 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 9E271C433B4 for ; Wed, 12 May 2021 15:32:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7328961CC8 for ; Wed, 12 May 2021 15:32:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234489AbhELPco (ORCPT ); Wed, 12 May 2021 11:32:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:40904 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235598AbhELP2h (ORCPT ); Wed, 12 May 2021 11:28:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8FF3F61C2D; Wed, 12 May 2021 15:14:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620832447; bh=Lo8JRyfuPvNpfhP/tzstJnRxe2FkI0ErN1Kifgb3tR0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U/hJqlNz1Sqlp2SEUOeOLkrczh884D1h+YYRvhrOhyuioIQdc6mIu8/FpoZ3fKllm rrTwU+T7cXJAvG60svIYEZNEb4qF1Nd7J9L1G4j1x0KDHMsspJBleAO8UqbzipWrDt lMeX9/TrZxWqR6ovG5dpB7R6gCht/DSB4TA7rA40= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhouyi Zhou , "Paul E. McKenney" , Sasha Levin Subject: [PATCH 5.10 283/530] rcu: Remove spurious instrumentation_end() in rcu_nmi_enter() Date: Wed, 12 May 2021 16:46:33 +0200 Message-Id: <20210512144829.108260353@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144819.664462530@linuxfoundation.org> References: <20210512144819.664462530@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhouyi Zhou [ Upstream commit 6494ccb93271bee596a12db32ff44867d5be2321 ] 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 Signed-off-by: Sasha Levin --- kernel/rcu/tree.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 8a5cc76ecac9..61e250cdd7c9 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1019,7 +1019,6 @@ noinstr void rcu_nmi_enter(void) } else if (!in_nmi()) { instrumentation_begin(); rcu_irq_enter_check_tick(); - instrumentation_end(); } else { instrumentation_begin(); }