From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: [PATCH V2 01/10] PM / OPP: Fix memory leak while adding duplicate OPPs Date: Wed, 7 Dec 2016 10:11:57 +0530 Message-ID: References: Return-path: Received: from mail-pf0-f181.google.com ([209.85.192.181]:36141 "EHLO mail-pf0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750825AbcLGEmQ (ORCPT ); Tue, 6 Dec 2016 23:42:16 -0500 Received: by mail-pf0-f181.google.com with SMTP id 189so74743425pfz.3 for ; Tue, 06 Dec 2016 20:42:16 -0800 (PST) In-Reply-To: In-Reply-To: References: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Rafael Wysocki , Viresh Kumar , Nishanth Menon , Stephen Boyd Cc: linaro-kernel@lists.linaro.org, linux-pm@vger.kernel.org, Vincent Guittot , Viresh Kumar There are two types of duplicate OPPs that get different behavior from the core: A). An earlier OPP is marked 'available' and has same freq/voltages as the new one. B). An earlier OPP with same frequency, but is marked 'unavailable' OR doesn't have same voltages as the new one. The OPP core returns 0 for the first one, but -EEXIST for the second. While the OPP core returns 0 for the first case, its callers don't free the newly allocated OPP structure which isn't used anymore. Fix that by returning -EBUSY instead of 0, but make the callers return 0 eventually. As this isn't a critical fix, its not getting marked for stable kernel. Signed-off-by: Viresh Kumar --- drivers/base/power/opp/core.c | 18 ++++++++++++++++-- drivers/base/power/opp/of.c | 6 +++++- 2 files changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index a0e6294baf1d..9ff816217c6e 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -1080,6 +1080,16 @@ static bool _opp_supported_by_regulators(struct dev_pm_opp *opp, return true; } +/* + * Returns: + * 0: On success. And appropriate error message for duplicate OPPs. + * -EBUSY: For OPP with same freq/volt and is available. The callers of + * _opp_add() must return 0 if they receive -EBUSY from it. This is to make + * sure we don't print error messages unnecessarily if different parts of + * kernel try to initialize the OPP table. + * -EEXIST: For OPP with same freq but different volt or is unavailable. This + * should be considered an error by the callers of _opp_add(). + */ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, struct opp_table *opp_table) { @@ -1112,7 +1122,7 @@ int _opp_add(struct device *dev, struct dev_pm_opp *new_opp, /* Should we compare voltages for all regulators here ? */ return opp->available && - new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? 0 : -EEXIST; + new_opp->supplies[0].u_volt == opp->supplies[0].u_volt ? -EBUSY : -EEXIST; } new_opp->opp_table = opp_table; @@ -1186,8 +1196,12 @@ int _opp_add_v1(struct device *dev, unsigned long freq, long u_volt, new_opp->dynamic = dynamic; ret = _opp_add(dev, new_opp, opp_table); - if (ret) + if (ret) { + /* Don't return error for duplicate OPPs */ + if (ret == -EBUSY) + ret = 0; goto free_opp; + } mutex_unlock(&opp_table_lock); diff --git a/drivers/base/power/opp/of.c b/drivers/base/power/opp/of.c index 3f7d2591b173..356c75edd656 100644 --- a/drivers/base/power/opp/of.c +++ b/drivers/base/power/opp/of.c @@ -327,8 +327,12 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) goto free_opp; ret = _opp_add(dev, new_opp, opp_table); - if (ret) + if (ret) { + /* Don't return error for duplicate OPPs */ + if (ret == -EBUSY) + ret = 0; goto free_opp; + } /* OPP to select on device suspend */ if (of_property_read_bool(np, "opp-suspend")) { -- 2.7.1.410.g6faf27b