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=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 BDE3EC2BAEE for ; Tue, 24 Mar 2020 06:34:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96A1C20714 for ; Tue, 24 Mar 2020 06:34:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b="R/8QvpMM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726261AbgCXGev (ORCPT ); Tue, 24 Mar 2020 02:34:51 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:37645 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725867AbgCXGev (ORCPT ); Tue, 24 Mar 2020 02:34:51 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 48mhLc62Rfz9sNg; Tue, 24 Mar 2020 17:34:48 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1585031689; bh=5Hd5RUwA/dvRMS4WLUeTFYytdcYhONFN7COAZjGe2ZI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=R/8QvpMMOGOvB2SBheePKyqG/9FNKIhpvV3+NXp9oPbPnr+y+Y9FqYq/qftTI81jX TTJJBApqrx7RsVt31sowNMafRKvD2AdB1McUZOqNkhjOrbUDKQ4uFGYqGY+3NNmW+x k3eTAln+cKrDkMswlglr1RXo3ZPV/4XxBtcWZk29BLubGPvsLjOC2YdR8r3L7kBnU7 oEWw0zshCBZBDWXfTfThCWaOdaJEN3hX1YetFcGXhaw2RJaAFWMo9XQUwJUVJbMvNh 6m6AF1IIRf+LiR/B/PGMPJmkjY9mKTdM574qdqMbpLSCmHceo+yklU7l2SgL/O7khS m8Yv54tJrC0tg== From: Michael Ellerman To: "Rafael J. Wysocki" , Pratik Rajesh Sampat Cc: linux-pm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, pratik.r.sampat@gmail.com, ego@linux.vnet.ibm.com, dja@axtens.net Subject: Re: [PATCH] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn In-Reply-To: <1921198.IfoiWgUDIW@kreacher> References: <20200316135743.57735-1-psampat@linux.ibm.com> <1921198.IfoiWgUDIW@kreacher> Date: Tue, 24 Mar 2020 17:34:56 +1100 Message-ID: <87h7yexnu7.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "Rafael J. Wysocki" writes: > On Monday, March 16, 2020 2:57:43 PM CET Pratik Rajesh Sampat wrote: >> The patch avoids allocating cpufreq_policy on stack hence fixing frame >> size overflow in 'powernv_cpufreq_work_fn' >> >> Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling") >> Signed-off-by: Pratik Rajesh Sampat > > Any objections or concerns here? > > If not, I'll queue it up. I have it in my testing branch, but if you pick it up I can drop it. cheers >> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c >> index 56f4bc0d209e..20ee0661555a 100644 >> --- a/drivers/cpufreq/powernv-cpufreq.c >> +++ b/drivers/cpufreq/powernv-cpufreq.c >> @@ -902,6 +902,7 @@ static struct notifier_block powernv_cpufreq_reboot_nb = { >> void powernv_cpufreq_work_fn(struct work_struct *work) >> { >> struct chip *chip = container_of(work, struct chip, throttle); >> + struct cpufreq_policy *policy; >> unsigned int cpu; >> cpumask_t mask; >> >> @@ -916,12 +917,14 @@ void powernv_cpufreq_work_fn(struct work_struct *work) >> chip->restore = false; >> for_each_cpu(cpu, &mask) { >> int index; >> - struct cpufreq_policy policy; >> >> - cpufreq_get_policy(&policy, cpu); >> - index = cpufreq_table_find_index_c(&policy, policy.cur); >> - powernv_cpufreq_target_index(&policy, index); >> - cpumask_andnot(&mask, &mask, policy.cpus); >> + policy = cpufreq_cpu_get(cpu); >> + if (!policy) >> + continue; >> + index = cpufreq_table_find_index_c(policy, policy->cur); >> + powernv_cpufreq_target_index(policy, index); >> + cpumask_andnot(&mask, &mask, policy->cpus); >> + cpufreq_cpu_put(policy); >> } >> out: >> put_online_cpus(); >>