[PATCH V3 01/10] PM / OPP: Fix memory leak while adding duplicate OPPs
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: 2017-01-02 09:11:21
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lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, hibernation (aka software suspend, aka swsusp), power management core, suspend to ram, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
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 <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <redacted> --- 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 35ff06283738..a8a5e01b7756 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c@@ -1067,6 +1067,16 @@ 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) {
@@ -1099,7 +1109,7 @@ 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;
@@ -1173,8 +1183,12 @@ 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