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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7607EC4167D for ; Mon, 18 Apr 2022 14:02:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245520AbiDRODW (ORCPT ); Mon, 18 Apr 2022 10:03:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244626AbiDRNpK (ORCPT ); Mon, 18 Apr 2022 09:45:10 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3808B31DF5; Mon, 18 Apr 2022 06:00:13 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C81236097A; Mon, 18 Apr 2022 13:00:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF00BC385A7; Mon, 18 Apr 2022 13:00:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650286812; bh=4EkoxEUV+IdLa5MyNpD/AR455m8vghf+mXa9Xk9Yw+4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TEy+o2civ/gwWq2xyRykitti5LJczyUzXJixQLgqdPhTcmO2dVhSE+g+eh7SXfomY oQog4FeLk+s0hx1HK/bNErcQpaJpO5voh4ykVfs1Y/SET5WUPOWX6KW0s2wnH/mfCP aWTip7ZVeYVQnuqK0DB1ja5fe/Vw6N3PIOuZ/+6w= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiaomeng Tong , Will Deacon Subject: [PATCH 4.14 251/284] perf: qcom_l2_pmu: fix an incorrect NULL check on list iterator Date: Mon, 18 Apr 2022 14:13:52 +0200 Message-Id: <20220418121219.396089387@linuxfoundation.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220418121210.689577360@linuxfoundation.org> References: <20220418121210.689577360@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiaomeng Tong commit 2012a9e279013933885983cbe0a5fe828052563b upstream. The bug is here: return cluster; The list iterator value 'cluster' will *always* be set and non-NULL by list_for_each_entry(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element is found. To fix the bug, return 'cluster' when found, otherwise return NULL. Cc: stable@vger.kernel.org Fixes: 21bdbb7102ed ("perf: add qcom l2 cache perf events driver") Signed-off-by: Xiaomeng Tong Link: https://lore.kernel.org/r/20220327055733.4070-1-xiam0nd.tong@gmail.com Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- drivers/perf/qcom_l2_pmu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/perf/qcom_l2_pmu.c +++ b/drivers/perf/qcom_l2_pmu.c @@ -744,7 +744,7 @@ static struct cluster_pmu *l2_cache_asso { u64 mpidr; int cpu_cluster_id; - struct cluster_pmu *cluster = NULL; + struct cluster_pmu *cluster; /* * This assumes that the cluster_id is in MPIDR[aff1] for @@ -766,10 +766,10 @@ static struct cluster_pmu *l2_cache_asso cluster->cluster_id); cpumask_set_cpu(cpu, &cluster->cluster_cpus); *per_cpu_ptr(l2cache_pmu->pmu_cluster, cpu) = cluster; - break; + return cluster; } - return cluster; + return NULL; } static int l2cache_pmu_online_cpu(unsigned int cpu, struct hlist_node *node)