From 0edb040d416ab350c02ac710233349aeaf8c2a26 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Thu, 6 Dec 2018 13:43:37 +0100 Subject: [PATCH] regulator: core: Track dangling GPIO descriptors If a GPIO descriptor is passed to the regulator_register() function inside the config->ena_gpiod callers must be sure that once they call this API the regulator core owns that descriptor and will make sure to issue gpiod_put() on it, no matter whether the call is successful or not. For device tree regulators, the regulator core will automatically set up regulator init data from the device tree when registering a regulator by calling regulator_of_get_init_data() which in turn calls down to the regulator driver's .of_parse_cb() callback. This callback (in drivers such as for max77686) may also choose to fill in the config->ena_gpiod field with a GPIO descriptor. Harden the errorpath of regulator_register() to properly gpiod_put() any passed in cfg->ena_gpiod or any gpiod coming from the device tree on any type of error. Signed-off-by: Linus Walleij Reviewed-by: Marek Szyprowski Tested-by: Marek Szyprowski Reviewed-by: Charles Keepax Signed-off-by: Mark Brown --- drivers/regulator/core.c | 55 ++++++++++++++++++++++++++++++++-------- 1 file changed, 45 insertions(+), 10 deletions(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 757619878068..79cb090ff22f 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -4868,21 +4868,33 @@ regulator_register(const struct regulator_desc *regulator_desc, struct regulator_config *config = NULL; static atomic_t regulator_no = ATOMIC_INIT(-1); struct regulator_dev *rdev; + bool dangling_cfg_gpiod = false; + bool dangling_of_gpiod = false; struct device *dev; int ret, i; - if (regulator_desc == NULL || cfg == NULL) + if (cfg == NULL) return ERR_PTR(-EINVAL); + if (cfg->ena_gpiod) + dangling_cfg_gpiod = true; + if (regulator_desc == NULL) { + ret = -EINVAL; + goto rinse; + } dev = cfg->dev; WARN_ON(!dev); - if (regulator_desc->name == NULL || regulator_desc->ops == NULL) - return ERR_PTR(-EINVAL); + if (regulator_desc->name == NULL || regulator_desc->ops == NULL) { + ret = -EINVAL; + goto rinse; + } if (regulator_desc->type != REGULATOR_VOLTAGE && - regulator_desc->type != REGULATOR_CURRENT) - return ERR_PTR(-EINVAL); + regulator_desc->type != REGULATOR_CURRENT) { + ret = -EINVAL; + goto rinse; + } /* Only one of each should be implemented */ WARN_ON(regulator_desc->ops->get_voltage && @@ -4893,16 +4905,20 @@ regulator_register(const struct regulator_desc *regulator_desc, /* If we're using selectors we must implement list_voltage. */ if (regulator_desc->ops->get_voltage_sel && !regulator_desc->ops->list_voltage) { - return ERR_PTR(-EINVAL); + ret = -EINVAL; + goto rinse; } if (regulator_desc->ops->set_voltage_sel && !regulator_desc->ops->list_voltage) { - return ERR_PTR(-EINVAL); + ret = -EINVAL; + goto rinse; } rdev = kzalloc(sizeof(struct regulator_dev), GFP_KERNEL); - if (rdev == NULL) - return ERR_PTR(-ENOMEM); + if (rdev == NULL) { + ret = -ENOMEM; + goto rinse; + } /* * Duplicate the config so the driver could override it after @@ -4911,11 +4927,22 @@ regulator_register(const struct regulator_desc *regulator_desc, config = kmemdup(cfg, sizeof(*cfg), GFP_KERNEL); if (config == NULL) { kfree(rdev); - return ERR_PTR(-ENOMEM); + ret = -ENOMEM; + goto rinse; } init_data = regulator_of_get_init_data(dev, regulator_desc, config, &rdev->dev.of_node); + /* + * We need to keep track of any GPIO descriptor coming from the + * device tree until we have handled it over to the core. If the + * config that was passed in to this function DOES NOT contain + * a descriptor, and the config after this call DOES contain + * a descriptor, we definately got one from parsing the device + * tree. + */ + if (!cfg->ena_gpiod && config->ena_gpiod) + dangling_of_gpiod = true; if (!init_data) { init_data = config->init_data; rdev->dev.of_node = of_node_get(config->of_node); @@ -4954,6 +4981,9 @@ regulator_register(const struct regulator_desc *regulator_desc, config->ena_gpio, ret); goto clean; } + /* The regulator core took over the GPIO descriptor */ + dangling_cfg_gpiod = false; + dangling_of_gpiod = false; } /* register with sysfs */ @@ -5039,8 +5069,13 @@ regulator_register(const struct regulator_desc *regulator_desc, regulator_ena_gpio_free(rdev); mutex_unlock(®ulator_list_mutex); clean: + if (dangling_of_gpiod) + gpiod_put(config->ena_gpiod); kfree(rdev); kfree(config); +rinse: + if (dangling_cfg_gpiod) + gpiod_put(cfg->ena_gpiod); return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(regulator_register);