From nobody Sun Dec 28 11:51:57 2025 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 75139C4167B for ; Fri, 8 Dec 2023 22:06:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1574898AbjLHWGS (ORCPT ); Fri, 8 Dec 2023 17:06:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41444 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1574886AbjLHWFz (ORCPT ); Fri, 8 Dec 2023 17:05:55 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A980E1712 for ; Fri, 8 Dec 2023 14:06:01 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B8C95C433C7; Fri, 8 Dec 2023 22:05:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1702073161; bh=6Rj2/Ew9i8og8UV1rs/YRIIkk8Z14PNfosvKFa7ip4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VXojr6rgF4CVtj1/yBPc4JDT25DImi7RK6bjPnZ/E9+OwRt5xlCa7VBBdmwAuZRQk aSMyIc9cocqzJ7LMudOAEPf9o4ryZal2Oa/HV7IOcfmPXz4JSTHA6hflKzWJ/j5U04 47RHygrGazdzJEjuHxp0zlfgxtpGTF+qVfmMzN8SY2ZLR55GpJobnvyxwHk7UYALl7 4STCMLMjN779SK0D/wWSsCw1K+XE/WQfSuIe67z0e0HnM3EUh57lV7WsdRJ2iUezAj fb1y3eftmg/tb2vDlQw7dP4H+Gb2wIPAd2efJnXF2+n9aW8kKJTT1tmwcbg5O9rDhc iINxxKaf0URqg== From: Frederic Weisbecker To: LKML Cc: Frederic Weisbecker , Boqun Feng , Joel Fernandes , Neeraj Upadhyay , "Paul E . McKenney" , Uladzislau Rezki , Zqiang , rcu , Anna-Maria Behnsen , Thomas Gleixner , Kalesh Singh Subject: [PATCH 3/8] rcu/exp: Fix RCU expedited parallel grace period kworker allocation failure recovery Date: Fri, 8 Dec 2023 23:05:40 +0100 Message-ID: <20231208220545.7452-4-frederic@kernel.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231208220545.7452-1-frederic@kernel.org> References: <20231208220545.7452-1-frederic@kernel.org> 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" Under CONFIG_RCU_EXP_KTHREAD=3Dy, the nodes initialization for expedited grace periods is queued to a kworker. However if the allocation of that kworker failed, the nodes initialization is performed synchronously by the caller instead. Now the check for kworker initialization failure relies on the kworker pointer to be NULL while its value might actually encapsulate an allocation failure error. Make sure to handle this case. Fixes: 9621fbee44df ("rcu: Move expedited grace period (GP) work to RT kthr= ead_worker") Cc: Kalesh Singh Signed-off-by: Frederic Weisbecker Reviewed-by: Kalesh Singh --- kernel/rcu/tree.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 82f8130d3fe3..055f4817bc70 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4723,6 +4723,7 @@ static void __init rcu_start_exp_gp_kworkers(void) rcu_exp_par_gp_kworker =3D kthread_create_worker(0, par_gp_kworker_name); if (IS_ERR_OR_NULL(rcu_exp_par_gp_kworker)) { pr_err("Failed to create %s!\n", par_gp_kworker_name); + rcu_exp_par_gp_kworker =3D NULL; kthread_destroy_worker(rcu_exp_gp_kworker); return; } --=20 2.42.1