From f60d2b111cd55c335c2b70e50d66a612d2b10856 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 26 Jun 2006 01:48:36 -0400 Subject: [PATCH] Input: reset name, phys and uniq when unregistering Name, phys and uniq are quite often constant strings in moules implementing particular input device. If a module unregisters input device and then gets unloaded, the device could still be present in memory (pinned via sysfs), but aforementioned members would point to some random memory. Set them all to NULL when unregistering so sysfs handlers won't try dereferencing them. Signed-off-by: Dmitry Torokhov --- drivers/input/input.c | 19 ++++++++++++++++++- include/linux/input.h | 7 +------ 2 files changed, 19 insertions(+), 7 deletions(-) diff --git a/drivers/input/input.c b/drivers/input/input.c index b149c9434849..d3cdb139e962 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -29,6 +29,7 @@ MODULE_DESCRIPTION("Input core"); MODULE_LICENSE("GPL"); EXPORT_SYMBOL(input_allocate_device); +EXPORT_SYMBOL(input_free_device); EXPORT_SYMBOL(input_register_device); EXPORT_SYMBOL(input_unregister_device); EXPORT_SYMBOL(input_register_handler); @@ -872,6 +873,7 @@ struct input_dev *input_allocate_device(void) dev->dynalloc = 1; dev->cdev.class = &input_class; class_device_initialize(&dev->cdev); + mutex_init(&dev->mutex); INIT_LIST_HEAD(&dev->h_list); INIT_LIST_HEAD(&dev->node); } @@ -879,6 +881,18 @@ struct input_dev *input_allocate_device(void) return dev; } +void input_free_device(struct input_dev *dev) +{ + if (dev) { + + mutex_lock(&dev->mutex); + dev->name = dev->phys = dev->uniq = NULL; + mutex_unlock(&dev->mutex); + + input_put_device(dev); + } +} + int input_register_device(struct input_dev *dev) { static atomic_t input_no = ATOMIC_INIT(0); @@ -895,7 +909,6 @@ int input_register_device(struct input_dev *dev) return -EINVAL; } - mutex_init(&dev->mutex); set_bit(EV_SYN, dev->evbit); /* @@ -979,6 +992,10 @@ void input_unregister_device(struct input_dev *dev) sysfs_remove_group(&dev->cdev.kobj, &input_dev_attr_group); class_device_unregister(&dev->cdev); + mutex_lock(&dev->mutex); + dev->name = dev->phys = dev->uniq = NULL; + mutex_unlock(&dev->mutex); + input_wakeup_procfs_readers(); } diff --git a/include/linux/input.h b/include/linux/input.h index b32c2b6e53f6..8d2b874d9e72 100644 --- a/include/linux/input.h +++ b/include/linux/input.h @@ -1005,6 +1005,7 @@ static inline void init_input_dev(struct input_dev *dev) } struct input_dev *input_allocate_device(void); +void input_free_device(struct input_dev *dev); static inline struct input_dev *input_get_device(struct input_dev *dev) { @@ -1016,12 +1017,6 @@ static inline void input_put_device(struct input_dev *dev) class_device_put(&dev->cdev); } -static inline void input_free_device(struct input_dev *dev) -{ - if (dev) - input_put_device(dev); -} - int input_register_device(struct input_dev *); void input_unregister_device(struct input_dev *); -- 2.39.2