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path: root/drivers/input/input.c
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-rw-r--r--drivers/input/input.c65
1 files changed, 48 insertions, 17 deletions
diff --git a/drivers/input/input.c b/drivers/input/input.c
index c6f88ebb40c7..cc763c96fada 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -782,10 +782,29 @@ 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);
}
@@ -795,9 +814,12 @@ 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,
@@ -861,7 +883,7 @@ 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,
};
@@ -881,40 +903,49 @@ 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,
};
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