diff options
Diffstat (limited to 'drivers/gpio/gpiolib-cdev.c')
| -rw-r--r-- | drivers/gpio/gpiolib-cdev.c | 206 |
1 files changed, 180 insertions, 26 deletions
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 65b2c09a4576..e878e3f22b0e 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -57,6 +57,50 @@ static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8)); * interface to gpiolib GPIOs via ioctl()s. */ +typedef __poll_t (*poll_fn)(struct file *, struct poll_table_struct *); +typedef long (*ioctl_fn)(struct file *, unsigned int, unsigned long); +typedef ssize_t (*read_fn)(struct file *, char __user *, + size_t count, loff_t *); + +static __poll_t call_poll_locked(struct file *file, + struct poll_table_struct *wait, + struct gpio_device *gdev, poll_fn func) +{ + __poll_t ret; + + down_read(&gdev->sem); + ret = func(file, wait); + up_read(&gdev->sem); + + return ret; +} + +static long call_ioctl_locked(struct file *file, unsigned int cmd, + unsigned long arg, struct gpio_device *gdev, + ioctl_fn func) +{ + long ret; + + down_read(&gdev->sem); + ret = func(file, cmd, arg); + up_read(&gdev->sem); + + return ret; +} + +static ssize_t call_read_locked(struct file *file, char __user *buf, + size_t count, loff_t *f_ps, + struct gpio_device *gdev, read_fn func) +{ + ssize_t ret; + + down_read(&gdev->sem); + ret = func(file, buf, count, f_ps); + up_read(&gdev->sem); + + return ret; +} + /* * GPIO line handle management */ @@ -193,8 +237,8 @@ static long linehandle_set_config(struct linehandle_state *lh, return 0; } -static long linehandle_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) +static long linehandle_ioctl_unlocked(struct file *file, unsigned int cmd, + unsigned long arg) { struct linehandle_state *lh = file->private_data; void __user *ip = (void __user *)arg; @@ -203,6 +247,9 @@ static long linehandle_ioctl(struct file *file, unsigned int cmd, unsigned int i; int ret; + if (!lh->gdev->chip) + return -ENODEV; + switch (cmd) { case GPIOHANDLE_GET_LINE_VALUES_IOCTL: /* NOTE: It's okay to read values of output lines */ @@ -249,6 +296,15 @@ static long linehandle_ioctl(struct file *file, unsigned int cmd, } } +static long linehandle_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct linehandle_state *lh = file->private_data; + + return call_ioctl_locked(file, cmd, arg, lh->gdev, + linehandle_ioctl_unlocked); +} + #ifdef CONFIG_COMPAT static long linehandle_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg) @@ -412,7 +468,7 @@ out_free_lh: * @desc: the GPIO descriptor for this line. * @req: the corresponding line request * @irq: the interrupt triggered in response to events on this GPIO - * @eflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or + * @edflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or * GPIO_V2_LINE_FLAG_EDGE_FALLING, indicating the edge detection applied * @timestamp_ns: cache for the timestamp storing it between hardirq and * IRQ thread, used to bring the timestamp close to the actual event @@ -1380,12 +1436,15 @@ static long linereq_set_config(struct linereq *lr, void __user *ip) return ret; } -static long linereq_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) +static long linereq_ioctl_unlocked(struct file *file, unsigned int cmd, + unsigned long arg) { struct linereq *lr = file->private_data; void __user *ip = (void __user *)arg; + if (!lr->gdev->chip) + return -ENODEV; + switch (cmd) { case GPIO_V2_LINE_GET_VALUES_IOCTL: return linereq_get_values(lr, ip); @@ -1398,6 +1457,15 @@ static long linereq_ioctl(struct file *file, unsigned int cmd, } } +static long linereq_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct linereq *lr = file->private_data; + + return call_ioctl_locked(file, cmd, arg, lr->gdev, + linereq_ioctl_unlocked); +} + #ifdef CONFIG_COMPAT static long linereq_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg) @@ -1406,12 +1474,15 @@ static long linereq_ioctl_compat(struct file *file, unsigned int cmd, } #endif -static __poll_t linereq_poll(struct file *file, - struct poll_table_struct *wait) +static __poll_t linereq_poll_unlocked(struct file *file, + struct poll_table_struct *wait) { struct linereq *lr = file->private_data; __poll_t events = 0; + if (!lr->gdev->chip) + return EPOLLHUP | EPOLLERR; + poll_wait(file, &lr->wait, wait); if (!kfifo_is_empty_spinlocked_noirqsave(&lr->events, @@ -1421,16 +1492,25 @@ static __poll_t linereq_poll(struct file *file, return events; } -static ssize_t linereq_read(struct file *file, - char __user *buf, - size_t count, - loff_t *f_ps) +static __poll_t linereq_poll(struct file *file, + struct poll_table_struct *wait) +{ + struct linereq *lr = file->private_data; + + return call_poll_locked(file, wait, lr->gdev, linereq_poll_unlocked); +} + +static ssize_t linereq_read_unlocked(struct file *file, char __user *buf, + size_t count, loff_t *f_ps) { struct linereq *lr = file->private_data; struct gpio_v2_line_event le; ssize_t bytes_read = 0; int ret; + if (!lr->gdev->chip) + return -ENODEV; + if (count < sizeof(le)) return -EINVAL; @@ -1475,6 +1555,15 @@ static ssize_t linereq_read(struct file *file, return bytes_read; } +static ssize_t linereq_read(struct file *file, char __user *buf, + size_t count, loff_t *f_ps) +{ + struct linereq *lr = file->private_data; + + return call_read_locked(file, buf, count, f_ps, lr->gdev, + linereq_read_unlocked); +} + static void linereq_free(struct linereq *lr) { unsigned int i; @@ -1712,12 +1801,15 @@ struct lineevent_state { (GPIOEVENT_REQUEST_RISING_EDGE | \ GPIOEVENT_REQUEST_FALLING_EDGE) -static __poll_t lineevent_poll(struct file *file, - struct poll_table_struct *wait) +static __poll_t lineevent_poll_unlocked(struct file *file, + struct poll_table_struct *wait) { struct lineevent_state *le = file->private_data; __poll_t events = 0; + if (!le->gdev->chip) + return EPOLLHUP | EPOLLERR; + poll_wait(file, &le->wait, wait); if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock)) @@ -1726,15 +1818,21 @@ static __poll_t lineevent_poll(struct file *file, return events; } +static __poll_t lineevent_poll(struct file *file, + struct poll_table_struct *wait) +{ + struct lineevent_state *le = file->private_data; + + return call_poll_locked(file, wait, le->gdev, lineevent_poll_unlocked); +} + struct compat_gpioeevent_data { compat_u64 timestamp; u32 id; }; -static ssize_t lineevent_read(struct file *file, - char __user *buf, - size_t count, - loff_t *f_ps) +static ssize_t lineevent_read_unlocked(struct file *file, char __user *buf, + size_t count, loff_t *f_ps) { struct lineevent_state *le = file->private_data; struct gpioevent_data ge; @@ -1742,6 +1840,9 @@ static ssize_t lineevent_read(struct file *file, ssize_t ge_size; int ret; + if (!le->gdev->chip) + return -ENODEV; + /* * When compatible system call is being used the struct gpioevent_data, * in case of at least ia32, has different size due to the alignment @@ -1799,6 +1900,15 @@ static ssize_t lineevent_read(struct file *file, return bytes_read; } +static ssize_t lineevent_read(struct file *file, char __user *buf, + size_t count, loff_t *f_ps) +{ + struct lineevent_state *le = file->private_data; + + return call_read_locked(file, buf, count, f_ps, le->gdev, + lineevent_read_unlocked); +} + static void lineevent_free(struct lineevent_state *le) { if (le->irq) @@ -1816,13 +1926,16 @@ static int lineevent_release(struct inode *inode, struct file *file) return 0; } -static long lineevent_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) +static long lineevent_ioctl_unlocked(struct file *file, unsigned int cmd, + unsigned long arg) { struct lineevent_state *le = file->private_data; void __user *ip = (void __user *)arg; struct gpiohandle_data ghd; + if (!le->gdev->chip) + return -ENODEV; + /* * We can get the value for an event line but not set it, * because it is input by definition. @@ -1845,6 +1958,15 @@ static long lineevent_ioctl(struct file *file, unsigned int cmd, return -EINVAL; } +static long lineevent_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct lineevent_state *le = file->private_data; + + return call_ioctl_locked(file, cmd, arg, le->gdev, + lineevent_ioctl_unlocked); +} + #ifdef CONFIG_COMPAT static long lineevent_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg) @@ -2403,12 +2525,15 @@ static int lineinfo_changed_notify(struct notifier_block *nb, return NOTIFY_OK; } -static __poll_t lineinfo_watch_poll(struct file *file, - struct poll_table_struct *pollt) +static __poll_t lineinfo_watch_poll_unlocked(struct file *file, + struct poll_table_struct *pollt) { struct gpio_chardev_data *cdev = file->private_data; __poll_t events = 0; + if (!cdev->gdev->chip) + return EPOLLHUP | EPOLLERR; + poll_wait(file, &cdev->wait, pollt); if (!kfifo_is_empty_spinlocked_noirqsave(&cdev->events, @@ -2418,8 +2543,17 @@ static __poll_t lineinfo_watch_poll(struct file *file, return events; } -static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, - size_t count, loff_t *off) +static __poll_t lineinfo_watch_poll(struct file *file, + struct poll_table_struct *pollt) +{ + struct gpio_chardev_data *cdev = file->private_data; + + return call_poll_locked(file, pollt, cdev->gdev, + lineinfo_watch_poll_unlocked); +} + +static ssize_t lineinfo_watch_read_unlocked(struct file *file, char __user *buf, + size_t count, loff_t *off) { struct gpio_chardev_data *cdev = file->private_data; struct gpio_v2_line_info_changed event; @@ -2427,6 +2561,9 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, int ret; size_t event_size; + if (!cdev->gdev->chip) + return -ENODEV; + #ifndef CONFIG_GPIO_CDEV_V1 event_size = sizeof(struct gpio_v2_line_info_changed); if (count < event_size) @@ -2494,6 +2631,15 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, return bytes_read; } +static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, + size_t count, loff_t *off) +{ + struct gpio_chardev_data *cdev = file->private_data; + + return call_read_locked(file, buf, count, off, cdev->gdev, + lineinfo_watch_read_unlocked); +} + /** * gpio_chrdev_open() - open the chardev for ioctl operations * @inode: inode for this chardev @@ -2507,13 +2653,17 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file) struct gpio_chardev_data *cdev; int ret = -ENOMEM; + down_read(&gdev->sem); + /* Fail on open if the backing gpiochip is gone */ - if (!gdev->chip) - return -ENODEV; + if (!gdev->chip) { + ret = -ENODEV; + goto out_unlock; + } cdev = kzalloc(sizeof(*cdev), GFP_KERNEL); if (!cdev) - return -ENOMEM; + goto out_unlock; cdev->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL); if (!cdev->watched_lines) @@ -2536,6 +2686,8 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file) if (ret) goto out_unregister_notifier; + up_read(&gdev->sem); + return ret; out_unregister_notifier: @@ -2545,6 +2697,8 @@ out_free_bitmap: bitmap_free(cdev->watched_lines); out_free_cdev: kfree(cdev); +out_unlock: + up_read(&gdev->sem); return ret; } |