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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 6BD53C43461 for ; Tue, 8 Sep 2020 19:18:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 362CB2137B for ; Tue, 8 Sep 2020 19:18:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599592701; bh=q3vBjvCt0Cagzm5812yCqvqral+gB1OvdBKbPXl4hk4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=csP6EkRwnZQjwL3xxXXJ9HWnMnE+r78oAwxNXkuudqdivDMay7h2eq/3YEIC8fqbu N3JuEKT1a/BNcU/5T5X6X0PYZzia3c7741WxsoR2iim3LcL2CXwikQVGyJPOLJzk4U CwLZongUXXhnB8qSqW22gt1ocJPWvL3mJAPg3354= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731999AbgIHTSS (ORCPT ); Tue, 8 Sep 2020 15:18:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:51452 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731146AbgIHQCx (ORCPT ); Tue, 8 Sep 2020 12:02:53 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8E89523D99; Tue, 8 Sep 2020 15:37:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599579457; bh=q3vBjvCt0Cagzm5812yCqvqral+gB1OvdBKbPXl4hk4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gr/X4SBLuLeeqs13Acc+0tVNgMzY7HRRIWoqSpB+NmsE4FnxUCMsrm6dcDA3ByaR0 YQDHXChoo5FP6VInJATwwLkKTNfBa4QMHod6tS32gm42PIZQUqXQCP8NO4BIrgAwRJ vYMySb0vtmHPRNpaBHNyt0usySPbVT0PYZzs+FKk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Naresh Kamboju , Anders Roxell , Viresh Kumar , Sasha Levin Subject: [PATCH 5.8 086/186] opp: Dont drop reference for an OPP table that was never parsed Date: Tue, 8 Sep 2020 17:23:48 +0200 Message-Id: <20200908152245.811400583@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200908152241.646390211@linuxfoundation.org> References: <20200908152241.646390211@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Viresh Kumar [ Upstream commit 922ff0759a16299e24cacfc981ac07914d8f1826 ] dev_pm_opp_remove_table() should drop a reference to the OPP table only if the DT OPP table was parsed earlier with a call to dev_pm_opp_of_add_table() earlier. Else it may end up dropping the reference to the OPP table, which was added as a result of other calls like dev_pm_opp_set_clkname(). And would hence result in undesirable behavior later on when caller would try to free the resource again. Fixes: 03758d60265c ("opp: Replace list_kref with a local counter") Reported-by: Naresh Kamboju Reported-by: Anders Roxell Tested-by: Naresh Kamboju Signed-off-by: Viresh Kumar Signed-off-by: Sasha Levin --- drivers/opp/core.c | 22 ++++++++++++++++------ drivers/opp/opp.h | 2 +- 2 files changed, 17 insertions(+), 7 deletions(-) diff --git a/drivers/opp/core.c b/drivers/opp/core.c index 8c90f78717723..91dcad982d362 100644 --- a/drivers/opp/core.c +++ b/drivers/opp/core.c @@ -1265,13 +1265,19 @@ void dev_pm_opp_remove(struct device *dev, unsigned long freq) } EXPORT_SYMBOL_GPL(dev_pm_opp_remove); -void _opp_remove_all_static(struct opp_table *opp_table) +bool _opp_remove_all_static(struct opp_table *opp_table) { struct dev_pm_opp *opp, *tmp; + bool ret = true; mutex_lock(&opp_table->lock); - if (!opp_table->parsed_static_opps || --opp_table->parsed_static_opps) + if (!opp_table->parsed_static_opps) { + ret = false; + goto unlock; + } + + if (--opp_table->parsed_static_opps) goto unlock; list_for_each_entry_safe(opp, tmp, &opp_table->opp_list, node) { @@ -1281,6 +1287,8 @@ void _opp_remove_all_static(struct opp_table *opp_table) unlock: mutex_unlock(&opp_table->lock); + + return ret; } /** @@ -2382,13 +2390,15 @@ void _dev_pm_opp_find_and_remove_table(struct device *dev) return; } - _opp_remove_all_static(opp_table); + /* + * Drop the extra reference only if the OPP table was successfully added + * with dev_pm_opp_of_add_table() earlier. + **/ + if (_opp_remove_all_static(opp_table)) + dev_pm_opp_put_opp_table(opp_table); /* Drop reference taken by _find_opp_table() */ dev_pm_opp_put_opp_table(opp_table); - - /* Drop reference taken while the OPP table was added */ - dev_pm_opp_put_opp_table(opp_table); } /** diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h index e51646ff279eb..c3fcd571e446d 100644 --- a/drivers/opp/opp.h +++ b/drivers/opp/opp.h @@ -212,7 +212,7 @@ struct opp_table { /* Routines internal to opp core */ void dev_pm_opp_get(struct dev_pm_opp *opp); -void _opp_remove_all_static(struct opp_table *opp_table); +bool _opp_remove_all_static(struct opp_table *opp_table); void _get_opp_table_kref(struct opp_table *opp_table); int _get_opp_count(struct opp_table *opp_table); struct opp_table *_find_opp_table(struct device *dev); -- 2.25.1