From 6706664d92ea841913d5fcfd06c290fbe6d33bd2 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 20 Jul 2015 16:02:49 -0700 Subject: rtc: class: fix double free in rtc_register_device() error path Commit 59cca865f21e ("drivers/rtc/class.c: fix device_register() error handling") correctly noted that naked kfree() should not be used after failed device_register() call, however, while it added the needed put_device() it forgot to remove the original kfree() causing double-free. Cc: Vasiliy Kulikov Signed-off-by: Dmitry Torokhov Reviewed-by: Krzysztof Kozlowski Signed-off-by: Alexandre Belloni --- drivers/rtc/class.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'drivers/rtc/class.c') diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index ea2a315df6b7..eb82ec2a21bd 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -234,8 +234,9 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev, err = device_register(&rtc->dev); if (err) { + /* This will free both memory and the ID */ put_device(&rtc->dev); - goto exit_kfree; + goto exit; } rtc_dev_add_device(rtc); @@ -247,9 +248,6 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev, return rtc; -exit_kfree: - kfree(rtc); - exit_ida: ida_simple_remove(&rtc_ida, id); -- cgit v1.2.3 From c3b399a4b6703a04ef6eb3efe35ff12163e409e0 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 20 Jul 2015 16:02:50 -0700 Subject: rtc: class: remove unnecessary device_get() in rtc_device_unregister Technically the address of rtc->dev can never be NULL, so get_device() can never fail. Also caller of rtc_device_unregister() supposed to be the owner of the device and thus have a valid reference. Therefore call to get_device() is not needed here. Signed-off-by: Dmitry Torokhov Reviewed-by: Krzysztof Kozlowski Signed-off-by: Alexandre Belloni --- drivers/rtc/class.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) (limited to 'drivers/rtc/class.c') diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index eb82ec2a21bd..de7707f7e766 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -266,19 +266,18 @@ EXPORT_SYMBOL_GPL(rtc_device_register); */ void rtc_device_unregister(struct rtc_device *rtc) { - if (get_device(&rtc->dev) != NULL) { - mutex_lock(&rtc->ops_lock); - /* remove innards of this RTC, then disable it, before - * letting any rtc_class_open() users access it again - */ - rtc_sysfs_del_device(rtc); - rtc_dev_del_device(rtc); - rtc_proc_del_device(rtc); - device_unregister(&rtc->dev); - rtc->ops = NULL; - mutex_unlock(&rtc->ops_lock); - put_device(&rtc->dev); - } + mutex_lock(&rtc->ops_lock); + /* + * Remove innards of this RTC, then disable it, before + * letting any rtc_class_open() users access it again + */ + rtc_sysfs_del_device(rtc); + rtc_dev_del_device(rtc); + rtc_proc_del_device(rtc); + device_del(&rtc->dev); + rtc->ops = NULL; + mutex_unlock(&rtc->ops_lock); + put_device(&rtc->dev); } EXPORT_SYMBOL_GPL(rtc_device_unregister); -- cgit v1.2.3 From 3ee2c40b7ac2bf121aaa1176d8ac25b6a26e3a94 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Thu, 23 Jul 2015 16:01:08 -0700 Subject: rtc: switch to using is_visible() to control sysfs attributes Instead of creating wakealarm attribute manually, after the device has been registered, let's rely on facilities provided by the attribute groups to control which attributes are visible and which are not. This allows to create all needed attributes at once, at the same time that we register RTC class device. Signed-off-by: Dmitry Torokhov Reviewed-by: Krzysztof Kozlowski Signed-off-by: Alexandre Belloni --- drivers/rtc/class.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers/rtc/class.c') diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index de7707f7e766..de86578bcd6d 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -202,6 +202,7 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev, rtc->max_user_freq = 64; rtc->dev.parent = dev; rtc->dev.class = rtc_class; + rtc->dev.groups = rtc_get_dev_attribute_groups(); rtc->dev.release = rtc_device_release; mutex_init(&rtc->ops_lock); @@ -240,7 +241,6 @@ struct rtc_device *rtc_device_register(const char *name, struct device *dev, } rtc_dev_add_device(rtc); - rtc_sysfs_add_device(rtc); rtc_proc_add_device(rtc); dev_info(dev, "rtc core: registered %s as %s\n", @@ -271,7 +271,6 @@ void rtc_device_unregister(struct rtc_device *rtc) * Remove innards of this RTC, then disable it, before * letting any rtc_class_open() users access it again */ - rtc_sysfs_del_device(rtc); rtc_dev_del_device(rtc); rtc_proc_del_device(rtc); device_del(&rtc->dev); @@ -360,7 +359,6 @@ static int __init rtc_init(void) } rtc_class->pm = RTC_CLASS_DEV_PM_OPS; rtc_dev_init(); - rtc_sysfs_init(rtc_class); return 0; } -- cgit v1.2.3