From nobody Sat Jun 20 01:55:04 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3F73C433EF for ; Thu, 24 Mar 2022 11:14:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349712AbiCXLQV (ORCPT ); Thu, 24 Mar 2022 07:16:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239751AbiCXLQT (ORCPT ); Thu, 24 Mar 2022 07:16:19 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC8219F6C8; Thu, 24 Mar 2022 04:14:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1648120487; x=1679656487; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=82T1//IDxRxWMoKx8jXyzu8qZyLKygsREbSeX2E2PMA=; b=jltTZbK5SuOJnc7mZDr4RSP8jJWju0AcCNLisFii5n3n/f3NDDclPeSQ cczdu1oPQdO3ztM7k4bwEPATbzvFhZnUHgqTRLwbSWaiIXC0Ha6JrBsPU 7p6d8ajmBjcBFsfqbpx9mbOjnw1kknBT6KY5bCs0hJD0f4M0ftjGAYuHe GsOYQ8VWto2G3Fy6gpxWCMH1S+lZGPugTJkp0Te3OmsRjrHZan4j6NQu8 86Uv5C0P3vyGV6ks4FvtxQVn5hDsXE6Js7kKIS39JSRSvqRMi7p40BVlK qeEs5zcWiwQRYJ42E1kN6VRr7Cs3vjNYy+nJiN/qVowoBk3yy0u/ggkzQ g==; X-IronPort-AV: E=McAfee;i="6200,9189,10295"; a="258302716" X-IronPort-AV: E=Sophos;i="5.90,207,1643702400"; d="scan'208";a="258302716" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2022 04:14:41 -0700 X-IronPort-AV: E=Sophos;i="5.90,207,1643702400"; d="scan'208";a="519742130" Received: from zq-optiplex-7090.bj.intel.com ([10.238.156.125]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2022 04:14:39 -0700 From: Zqiang To: paulmck@kernel.org, frederic@kernel.org, quic_neeraju@quicinc.com Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] rcu: Check the validity of the boost_kthread_task pointer Date: Thu, 24 Mar 2022 19:15:15 +0800 Message-Id: <20220324111515.1810160-1-qiang1.zhang@intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The boost kthreads may spawn failed, although the probability of creation failure is very low, in consideration of the robustness of the code, add boost_kthread_task pointer detection. Signed-off-by: Zqiang --- kernel/rcu/tree_plugin.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 6b9bcd45c7b2..fd642f14f31f 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1125,7 +1125,8 @@ static void rcu_initiate_boost(struct rcu_node *rnp, = unsigned long flags) __releases(rnp->lock) { raw_lockdep_assert_held_rcu_node(rnp); - if (!rcu_preempt_blocked_readers_cgp(rnp) && rnp->exp_tasks =3D=3D NULL) { + if (!rnp->boost_kthread_task || + (!rcu_preempt_blocked_readers_cgp(rnp) && rnp->exp_tasks =3D=3D NULL)) { raw_spin_unlock_irqrestore_rcu_node(rnp, flags); return; } --=20 2.25.1