diff options
| -rw-r--r-- | drivers/input/input.c | 65 |
1 files changed, 48 insertions, 17 deletions
diff --git a/drivers/input/input.c b/drivers/input/input.c index b8ed4294fcc..60a4eaabb7d 100644 --- a/drivers/input/input.c +++ b/drivers/input/input.c @@ -781,10 +781,29 @@ static unsigned int input_proc_devices_poll(struct file *file, poll_table *wait) return 0; } +union input_seq_state { + struct { + unsigned short pos; + bool mutex_acquired; + }; + void *p; +}; + static void *input_devices_seq_start(struct seq_file *seq, loff_t *pos) { - if (mutex_lock_interruptible(&input_mutex)) - return NULL; + union input_seq_state *state = (union input_seq_state *)&seq->private; + int error; + + /* We need to fit into seq->private pointer */ + BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private)); + + error = mutex_lock_interruptible(&input_mutex); + if (error) { + state->mutex_acquired = false; + return ERR_PTR(error); + } + + state->mutex_acquired = true; return seq_list_start(&input_dev_list, *pos); } @@ -794,9 +813,12 @@ static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos) return seq_list_next(v, &input_dev_list, pos); } -static void input_devices_seq_stop(struct seq_file *seq, void *v) +static void input_seq_stop(struct seq_file *seq, void *v) { - mutex_unlock(&input_mutex); + union input_seq_state *state = (union input_seq_state *)&seq->private; + + if (state->mutex_acquired) + mutex_unlock(&input_mutex); } static void input_seq_print_bitmap(struct seq_file *seq, const char *name, @@ -860,7 +882,7 @@ static int input_devices_seq_show(struct seq_file *seq, void *v) static const struct seq_operations input_devices_seq_ops = { .start = input_devices_seq_start, .next = input_devices_seq_next, - .stop = input_devices_seq_stop, + .stop = input_seq_stop, .show = input_devices_seq_show, }; @@ -880,40 +902,49 @@ static const struct file_operations input_devices_fileops = { static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos) { - if (mutex_lock_interruptible(&input_mutex)) - return NULL; + union input_seq_state *state = (union input_seq_state *)&seq->private; + int error; + + /* We need to fit into seq->private pointer */ + BUILD_BUG_ON(sizeof(union input_seq_state) != sizeof(seq->private)); + + error = mutex_lock_interruptible(&input_mutex); + if (error) { + state->mutex_acquired = false; + return ERR_PTR(error); + } + + state->mutex_acquired = true; + state->pos = *pos; - seq->private = (void *)(unsigned long)*pos; return seq_list_start(&input_handler_list, *pos); } static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos) { - seq->private = (void *)(unsigned long)(*pos + 1); - return seq_list_next(v, &input_handler_list, pos); -} + union input_seq_state *state = (union input_seq_state *)&seq->private; -static void input_handlers_seq_stop(struct seq_file *seq, void *v) -{ - mutex_unlock(&input_mutex); + state->pos = *pos + 1; + return seq_list_next(v, &input_handler_list, pos); } static int input_handlers_seq_show(struct seq_file *seq, void *v) { struct input_handler *handler = container_of(v, struct input_handler, node); + union input_seq_state *state = (union input_seq_state *)&seq->private; - seq_printf(seq, "N: Number=%ld Name=%s", - (unsigned long)seq->private, handler->name); + seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name); if (handler->fops) seq_printf(seq, " Minor=%d", handler->minor); seq_putc(seq, '\n'); return 0; } + static const struct seq_operations input_handlers_seq_ops = { .start = input_handlers_seq_start, .next = input_handlers_seq_next, - .stop = input_handlers_seq_stop, + .stop = input_seq_stop, .show = input_handlers_seq_show, }; |