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=-20.5 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,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 55799C6377D for ; Wed, 21 Jul 2021 21:04:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4E4A7613FE for ; Wed, 21 Jul 2021 21:04:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229928AbhGUUYK (ORCPT ); Wed, 21 Jul 2021 16:24:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:34900 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229607AbhGUUYH (ORCPT ); Wed, 21 Jul 2021 16:24:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8A3FB613DC; Wed, 21 Jul 2021 21:04:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626901483; bh=osXoyN8oxvcAmu4jmKsY8xk1fGp7eKsWJyNJBNXs/go=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iZl7iJqLthsI05zmcgojc1wt/LrcFBn+wPQYVUlrY9gToEPnBBZKhtaw1t8MAm1gO OEi4C9Up+aNELoEl1+EyWlzkoRMbmHv4K49gK2yFODwKG1lpd1OryZ5CRXHMhOWuf1 fwSXxX+wry+w3G0RGGoOztwvHLhPNl8DSnYMYufwfSEN54tPjhjrMsab7bbg5dlB0+ 4pWClXay2Ad6vplrwOa6a/mPlueUbuGCG27TTxtt0NRL5Ev3O43mPdCD0KCynDQ0GP E+4eEgtuVusWnTLBf0tloxdzw4FggnmljTKTiXXz8870y5PuGuavCMApY3XPxZgHQL DNlcuFK7kxCDA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 365435C0D47; Wed, 21 Jul 2021 14:04:43 -0700 (PDT) From: "Paul E. McKenney" 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, "Paul E. McKenney" Subject: [PATCH rcu 7/7] scftorture: Avoid NULL pointer exception on early exit Date: Wed, 21 Jul 2021 14:04:41 -0700 Message-Id: <20210721210441.796995-7-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20210721210421.GA788053@paulmck-ThinkPad-P17-Gen-1> References: <20210721210421.GA788053@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org When scftorture finds an error in the module parameters controlling the relative frequencies of smp_call_function*() variants, it takes an early exit. So early that it has not allocated memory to track the kthreads running the test, which results in a segfault. This commit therefore checks for the existence of the memory before attempting to stop the kthreads that would otherwise have been recorded in that non-existent memory. Signed-off-by: Paul E. McKenney --- kernel/scftorture.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/scftorture.c b/kernel/scftorture.c index 5cf40e4383191..64a08288b1a6d 100644 --- a/kernel/scftorture.c +++ b/kernel/scftorture.c @@ -513,7 +513,7 @@ static void scf_torture_cleanup(void) return; WRITE_ONCE(scfdone, true); - if (nthreads) + if (nthreads && scf_stats_p) for (i = 0; i < nthreads; i++) torture_stop_kthread("scftorture_invoker", scf_stats_p[i].task); else -- 2.31.1.189.g2e36527f23