1 files changed, 409 insertions, 316 deletions

diff --git a/drivers/input/input.c b/drivers/input/input.c
index 711485437567..ec4346f20efd 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -96,48 +96,16 @@ static void input_start_autorepeat(struct input_dev *dev, int code)
 
 static void input_stop_autorepeat(struct input_dev *dev)
 {
-	del_timer(&dev->timer);
-}
-
-/*
- * Pass event first through all filters and then, if event has not been
- * filtered out, through all open handles. This function is called with
- * dev->event_lock held and interrupts disabled.
- */
-static unsigned int input_to_handler(struct input_handle *handle,
-			struct input_value *vals, unsigned int count)
-{
-	struct input_handler *handler = handle->handler;
-	struct input_value *end = vals;
-	struct input_value *v;
-
-	if (handler->filter) {
-		for (v = vals; v != vals + count; v++) {
-			if (handler->filter(handle, v->type, v->code, v->value))
-				continue;
-			if (end != v)
-				*end = *v;
-			end++;
-		}
-		count = end - vals;
-	}
-
-	if (!count)
-		return 0;
-
-	if (handler->events)
-		handler->events(handle, vals, count);
-	else if (handler->event)
-		for (v = vals; v != vals + count; v++)
-			handler->event(handle, v->type, v->code, v->value);
-
-	return count;
+	timer_delete(&dev->timer);
 }
 
 /*
  * Pass values first through all filters and then, if event has not been
- * filtered out, through all open handles. This function is called with
- * dev->event_lock held and interrupts disabled.
+ * filtered out, through all open handles. This order is achieved by placing
+ * filters at the head of the list of handles attached to the device, and
+ * placing regular handles at the tail of the list.
+ *
+ * This function is called with dev->event_lock held and interrupts disabled.
  */
 static void input_pass_values(struct input_dev *dev,
 			      struct input_value *vals, unsigned int count)
@@ -147,25 +115,23 @@ static void input_pass_values(struct input_dev *dev,
 
 	lockdep_assert_held(&dev->event_lock);
 
-	if (!count)
-		return;
-
-	rcu_read_lock();
+	scoped_guard(rcu) {
+		handle = rcu_dereference(dev->grab);
+		if (handle) {
+			count = handle->handle_events(handle, vals, count);
+			break;
+		}
 
-	handle = rcu_dereference(dev->grab);
-	if (handle) {
-		count = input_to_handler(handle, vals, count);
-	} else {
-		list_for_each_entry_rcu(handle, &dev->h_list, d_node)
+		list_for_each_entry_rcu(handle, &dev->h_list, d_node) {
 			if (handle->open) {
-				count = input_to_handler(handle, vals, count);
+				count = handle->handle_events(handle, vals,
+							      count);
 				if (!count)
 					break;
 			}
+		}
 	}
 
-	rcu_read_unlock();
-
 	/* trigger auto repeat for key events */
 	if (test_bit(EV_REP, dev->evbit) && test_bit(EV_KEY, dev->evbit)) {
 		for (v = vals; v != vals + count; v++) {
@@ -354,9 +320,6 @@ static void input_event_dispose(struct input_dev *dev, int disposition,
 	if ((disposition & INPUT_PASS_TO_DEVICE) && dev->event)
 		dev->event(dev, type, code, value);
 
-	if (!dev->vals)
-		return;
-
 	if (disposition & INPUT_PASS_TO_HANDLERS) {
 		struct input_value *v;
 
@@ -427,13 +390,9 @@ void input_handle_event(struct input_dev *dev,
 void input_event(struct input_dev *dev,
 		 unsigned int type, unsigned int code, int value)
 {
-	unsigned long flags;
-
 	if (is_event_supported(type, dev->evbit, EV_MAX)) {
-
-		spin_lock_irqsave(&dev->event_lock, flags);
+		guard(spinlock_irqsave)(&dev->event_lock);
 		input_handle_event(dev, type, code, value);
-		spin_unlock_irqrestore(&dev->event_lock, flags);
 	}
 }
 EXPORT_SYMBOL(input_event);
@@ -454,18 +413,15 @@ void input_inject_event(struct input_handle *handle,
 {
 	struct input_dev *dev = handle->dev;
 	struct input_handle *grab;
-	unsigned long flags;
 
 	if (is_event_supported(type, dev->evbit, EV_MAX)) {
-		spin_lock_irqsave(&dev->event_lock, flags);
+		guard(spinlock_irqsave)(&dev->event_lock);
+		guard(rcu)();
 
-		rcu_read_lock();
 		grab = rcu_dereference(dev->grab);
 		if (!grab || grab == handle)
 			input_handle_event(dev, type, code, value);
-		rcu_read_unlock();
 
-		spin_unlock_irqrestore(&dev->event_lock, flags);
 	}
 }
 EXPORT_SYMBOL(input_inject_event);
@@ -563,22 +519,15 @@ EXPORT_SYMBOL(input_copy_abs);
 int input_grab_device(struct input_handle *handle)
 {
 	struct input_dev *dev = handle->dev;
-	int retval;
 
-	retval = mutex_lock_interruptible(&dev->mutex);
-	if (retval)
-		return retval;
+	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
+		if (dev->grab)
+			return -EBUSY;
 
-	if (dev->grab) {
-		retval = -EBUSY;
-		goto out;
+		rcu_assign_pointer(dev->grab, handle);
 	}
 
-	rcu_assign_pointer(dev->grab, handle);
-
- out:
-	mutex_unlock(&dev->mutex);
-	return retval;
+	return 0;
 }
 EXPORT_SYMBOL(input_grab_device);
 
@@ -613,9 +562,8 @@ void input_release_device(struct input_handle *handle)
 {
 	struct input_dev *dev = handle->dev;
 
-	mutex_lock(&dev->mutex);
+	guard(mutex)(&dev->mutex);
 	__input_release_device(handle);
-	mutex_unlock(&dev->mutex);
 }
 EXPORT_SYMBOL(input_release_device);
 
@@ -629,64 +577,57 @@ EXPORT_SYMBOL(input_release_device);
 int input_open_device(struct input_handle *handle)
 {
 	struct input_dev *dev = handle->dev;
-	int retval;
-
-	retval = mutex_lock_interruptible(&dev->mutex);
-	if (retval)
-		return retval;
+	int error;
 
-	if (dev->going_away) {
-		retval = -ENODEV;
-		goto out;
-	}
+	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
+		if (dev->going_away)
+			return -ENODEV;
 
-	handle->open++;
+		handle->open++;
 
-	if (dev->users++ || dev->inhibited) {
-		/*
-		 * Device is already opened and/or inhibited,
-		 * so we can exit immediately and report success.
-		 */
-		goto out;
-	}
+		if (handle->handler->passive_observer)
+			return 0;
 
-	if (dev->open) {
-		retval = dev->open(dev);
-		if (retval) {
-			dev->users--;
-			handle->open--;
+		if (dev->users++ || dev->inhibited) {
 			/*
-			 * Make sure we are not delivering any more events
-			 * through this handle
+			 * Device is already opened and/or inhibited,
+			 * so we can exit immediately and report success.
 			 */
-			synchronize_rcu();
-			goto out;
+			return 0;
 		}
-	}
 
-	if (dev->poller)
-		input_dev_poller_start(dev->poller);
+		if (dev->open) {
+			error = dev->open(dev);
+			if (error) {
+				dev->users--;
+				handle->open--;
+				/*
+				 * Make sure we are not delivering any more
+				 * events through this handle.
+				 */
+				synchronize_rcu();
+				return error;
+			}
+		}
 
- out:
-	mutex_unlock(&dev->mutex);
-	return retval;
+		if (dev->poller)
+			input_dev_poller_start(dev->poller);
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL(input_open_device);
 
 int input_flush_device(struct input_handle *handle, struct file *file)
 {
 	struct input_dev *dev = handle->dev;
-	int retval;
-
-	retval = mutex_lock_interruptible(&dev->mutex);
-	if (retval)
-		return retval;
 
-	if (dev->flush)
-		retval = dev->flush(dev, file);
+	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
+		if (dev->flush)
+			return dev->flush(dev, file);
+	}
 
-	mutex_unlock(&dev->mutex);
-	return retval;
+	return 0;
 }
 EXPORT_SYMBOL(input_flush_device);
 
@@ -701,15 +642,17 @@ void input_close_device(struct input_handle *handle)
 {
 	struct input_dev *dev = handle->dev;
 
-	mutex_lock(&dev->mutex);
+	guard(mutex)(&dev->mutex);
 
 	__input_release_device(handle);
 
-	if (!--dev->users && !dev->inhibited) {
-		if (dev->poller)
-			input_dev_poller_stop(dev->poller);
-		if (dev->close)
-			dev->close(dev);
+	if (!handle->handler->passive_observer) {
+		if (!--dev->users && !dev->inhibited) {
+			if (dev->poller)
+				input_dev_poller_stop(dev->poller);
+			if (dev->close)
+				dev->close(dev);
+		}
 	}
 
 	if (!--handle->open) {
@@ -720,8 +663,6 @@ void input_close_device(struct input_handle *handle)
 		 */
 		synchronize_rcu();
 	}
-
-	mutex_unlock(&dev->mutex);
 }
 EXPORT_SYMBOL(input_close_device);
 
@@ -758,11 +699,10 @@ static void input_disconnect_device(struct input_dev *dev)
 	 * not to protect access to dev->going_away but rather to ensure
 	 * that there are no threads in the middle of input_open_device()
 	 */
-	mutex_lock(&dev->mutex);
-	dev->going_away = true;
-	mutex_unlock(&dev->mutex);
+	scoped_guard(mutex, &dev->mutex)
+		dev->going_away = true;
 
-	spin_lock_irq(&dev->event_lock);
+	guard(spinlock_irq)(&dev->event_lock);
 
 	/*
 	 * Simulate keyup events for all pressed keys so that handlers
@@ -775,8 +715,6 @@ static void input_disconnect_device(struct input_dev *dev)
 
 	list_for_each_entry(handle, &dev->h_list, d_node)
 		handle->open = 0;
-
-	spin_unlock_irq(&dev->event_lock);
 }
 
 /**
@@ -933,14 +871,9 @@ static int input_default_setkeycode(struct input_dev *dev,
  */
 int input_get_keycode(struct input_dev *dev, struct input_keymap_entry *ke)
 {
-	unsigned long flags;
-	int retval;
-
-	spin_lock_irqsave(&dev->event_lock, flags);
-	retval = dev->getkeycode(dev, ke);
-	spin_unlock_irqrestore(&dev->event_lock, flags);
+	guard(spinlock_irqsave)(&dev->event_lock);
 
-	return retval;
+	return dev->getkeycode(dev, ke);
 }
 EXPORT_SYMBOL(input_get_keycode);
 
@@ -955,18 +888,17 @@ EXPORT_SYMBOL(input_get_keycode);
 int input_set_keycode(struct input_dev *dev,
 		      const struct input_keymap_entry *ke)
 {
-	unsigned long flags;
 	unsigned int old_keycode;
-	int retval;
+	int error;
 
 	if (ke->keycode > KEY_MAX)
 		return -EINVAL;
 
-	spin_lock_irqsave(&dev->event_lock, flags);
+	guard(spinlock_irqsave)(&dev->event_lock);
 
-	retval = dev->setkeycode(dev, ke, &old_keycode);
-	if (retval)
-		goto out;
+	error = dev->setkeycode(dev, ke, &old_keycode);
+	if (error)
+		return error;
 
 	/* Make sure KEY_RESERVED did not get enabled. */
 	__clear_bit(KEY_RESERVED, dev->keybit);
@@ -994,10 +926,7 @@ int input_set_keycode(struct input_dev *dev,
 				    EV_SYN, SYN_REPORT, 1);
 	}
 
- out:
-	spin_unlock_irqrestore(&dev->event_lock, flags);
-
-	return retval;
+	return 0;
 }
 EXPORT_SYMBOL(input_set_keycode);
 
@@ -1116,33 +1045,31 @@ static inline void input_wakeup_procfs_readers(void)
 	wake_up(&input_devices_poll_wait);
 }
 
+struct input_seq_state {
+	unsigned short pos;
+	bool mutex_acquired;
+	int input_devices_state;
+};
+
 static __poll_t input_proc_devices_poll(struct file *file, poll_table *wait)
 {
+	struct seq_file *seq = file->private_data;
+	struct input_seq_state *state = seq->private;
+
 	poll_wait(file, &input_devices_poll_wait, wait);
-	if (file->f_version != input_devices_state) {
-		file->f_version = input_devices_state;
+	if (state->input_devices_state != input_devices_state) {
+		state->input_devices_state = input_devices_state;
 		return EPOLLIN | EPOLLRDNORM;
 	}
 
 	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)
 {
-	union input_seq_state *state = (union input_seq_state *)&seq->private;
+	struct input_seq_state *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;
@@ -1161,7 +1088,7 @@ static void *input_devices_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 
 static void input_seq_stop(struct seq_file *seq, void *v)
 {
-	union input_seq_state *state = (union input_seq_state *)&seq->private;
+	struct input_seq_state *state = seq->private;
 
 	if (state->mutex_acquired)
 		mutex_unlock(&input_mutex);
@@ -1247,7 +1174,8 @@ static const struct seq_operations input_devices_seq_ops = {
 
 static int input_proc_devices_open(struct inode *inode, struct file *file)
 {
-	return seq_open(file, &input_devices_seq_ops);
+	return seq_open_private(file, &input_devices_seq_ops,
+				sizeof(struct input_seq_state));
 }
 
 static const struct proc_ops input_devices_proc_ops = {
@@ -1255,17 +1183,14 @@ static const struct proc_ops input_devices_proc_ops = {
 	.proc_poll	= input_proc_devices_poll,
 	.proc_read	= seq_read,
 	.proc_lseek	= seq_lseek,
-	.proc_release	= seq_release,
+	.proc_release	= seq_release_private,
 };
 
 static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
 {
-	union input_seq_state *state = (union input_seq_state *)&seq->private;
+	struct input_seq_state *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;
@@ -1280,7 +1205,7 @@ static void *input_handlers_seq_start(struct seq_file *seq, loff_t *pos)
 
 static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-	union input_seq_state *state = (union input_seq_state *)&seq->private;
+	struct input_seq_state *state = seq->private;
 
 	state->pos = *pos + 1;
 	return seq_list_next(v, &input_handler_list, pos);
@@ -1289,7 +1214,7 @@ static void *input_handlers_seq_next(struct seq_file *seq, void *v, loff_t *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;
+	struct input_seq_state *state = seq->private;
 
 	seq_printf(seq, "N: Number=%u Name=%s", state->pos, handler->name);
 	if (handler->filter)
@@ -1310,14 +1235,15 @@ static const struct seq_operations input_handlers_seq_ops = {
 
 static int input_proc_handlers_open(struct inode *inode, struct file *file)
 {
-	return seq_open(file, &input_handlers_seq_ops);
+	return seq_open_private(file, &input_handlers_seq_ops,
+				sizeof(struct input_seq_state));
 }
 
 static const struct proc_ops input_handlers_proc_ops = {
 	.proc_open	= input_proc_handlers_open,
 	.proc_read	= seq_read,
 	.proc_lseek	= seq_lseek,
-	.proc_release	= seq_release,
+	.proc_release	= seq_release_private,
 };
 
 static int __init input_proc_init(void)
@@ -1378,19 +1304,19 @@ static int input_print_modalias_bits(char *buf, int size,
 				     char name, const unsigned long *bm,
 				     unsigned int min_bit, unsigned int max_bit)
 {
-	int len = 0, i;
+	int bit = min_bit;
+	int len = 0;
 
 	len += snprintf(buf, max(size, 0), "%c", name);
-	for (i = min_bit; i < max_bit; i++)
-		if (bm[BIT_WORD(i)] & BIT_MASK(i))
-			len += snprintf(buf + len, max(size - len, 0), "%X,", i);
+	for_each_set_bit_from(bit, bm, max_bit)
+		len += snprintf(buf + len, max(size - len, 0), "%X,", bit);
 	return len;
 }
 
-static int input_print_modalias(char *buf, int size, const struct input_dev *id,
-				int add_cr)
+static int input_print_modalias_parts(char *buf, int size, int full_len,
+				      const struct input_dev *id)
 {
-	int len;
+	int len, klen, remainder, space;
 
 	len = snprintf(buf, max(size, 0),
 		       "input:b%04Xv%04Xp%04Xe%04X-",
@@ -1399,8 +1325,48 @@ static int input_print_modalias(char *buf, int size, const struct input_dev *id,
 
 	len += input_print_modalias_bits(buf + len, size - len,
 				'e', id->evbit, 0, EV_MAX);
-	len += input_print_modalias_bits(buf + len, size - len,
+
+	/*
+	 * Calculate the remaining space in the buffer making sure we
+	 * have place for the terminating 0.
+	 */
+	space = max(size - (len + 1), 0);
+
+	klen = input_print_modalias_bits(buf + len, size - len,
 				'k', id->keybit, KEY_MIN_INTERESTING, KEY_MAX);
+	len += klen;
+
+	/*
+	 * If we have more data than we can fit in the buffer, check
+	 * if we can trim key data to fit in the rest. We will indicate
+	 * that key data is incomplete by adding "+" sign at the end, like
+	 * this: * "k1,2,3,45,+,".
+	 *
+	 * Note that we shortest key info (if present) is "k+," so we
+	 * can only try to trim if key data is longer than that.
+	 */
+	if (full_len && size < full_len + 1 && klen > 3) {
+		remainder = full_len - len;
+		/*
+		 * We can only trim if we have space for the remainder
+		 * and also for at least "k+," which is 3 more characters.
+		 */
+		if (remainder <= space - 3) {
+			/*
+			 * We are guaranteed to have 'k' in the buffer, so
+			 * we need at least 3 additional bytes for storing
+			 * "+," in addition to the remainder.
+			 */
+			for (int i = size - 1 - remainder - 3; i >= 0; i--) {
+				if (buf[i] == 'k' || buf[i] == ',') {
+					strcpy(buf + i + 1, "+,");
+					len = i + 3; /* Not counting '\0' */
+					break;
+				}
+			}
+		}
+	}
+
 	len += input_print_modalias_bits(buf + len, size - len,
 				'r', id->relbit, 0, REL_MAX);
 	len += input_print_modalias_bits(buf + len, size - len,
@@ -1416,12 +1382,25 @@ static int input_print_modalias(char *buf, int size, const struct input_dev *id,
 	len += input_print_modalias_bits(buf + len, size - len,
 				'w', id->swbit, 0, SW_MAX);
 
-	if (add_cr)
-		len += snprintf(buf + len, max(size - len, 0), "\n");
-
 	return len;
 }
 
+static int input_print_modalias(char *buf, int size, const struct input_dev *id)
+{
+	int full_len;
+
+	/*
+	 * Printing is done in 2 passes: first one figures out total length
+	 * needed for the modalias string, second one will try to trim key
+	 * data in case when buffer is too small for the entire modalias.
+	 * If the buffer is too small regardless, it will fill as much as it
+	 * can (without trimming key data) into the buffer and leave it to
+	 * the caller to figure out what to do with the result.
+	 */
+	full_len = input_print_modalias_parts(NULL, 0, 0, id);
+	return input_print_modalias_parts(buf, size, full_len, id);
+}
+
 static ssize_t input_dev_show_modalias(struct device *dev,
 				       struct device_attribute *attr,
 				       char *buf)
@@ -1429,7 +1408,9 @@ static ssize_t input_dev_show_modalias(struct device *dev,
 	struct input_dev *id = to_input_dev(dev);
 	ssize_t len;
 
-	len = input_print_modalias(buf, PAGE_SIZE, id, 1);
+	len = input_print_modalias(buf, PAGE_SIZE, id);
+	if (len < PAGE_SIZE - 2)
+		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
 
 	return min_t(int, len, PAGE_SIZE);
 }
@@ -1641,6 +1622,23 @@ static int input_add_uevent_bm_var(struct kobj_uevent_env *env,
 	return 0;
 }
 
+/*
+ * This is a pretty gross hack. When building uevent data the driver core
+ * may try adding more environment variables to kobj_uevent_env without
+ * telling us, so we have no idea how much of the buffer we can use to
+ * avoid overflows/-ENOMEM elsewhere. To work around this let's artificially
+ * reduce amount of memory we will use for the modalias environment variable.
+ *
+ * The potential additions are:
+ *
+ * SEQNUM=18446744073709551615 - (%llu - 28 bytes)
+ * HOME=/ (6 bytes)
+ * PATH=/sbin:/bin:/usr/sbin:/usr/bin (34 bytes)
+ *
+ * 68 bytes total. Allow extra buffer - 96 bytes
+ */
+#define UEVENT_ENV_EXTRA_LEN	96
+
 static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
 					 const struct input_dev *dev)
 {
@@ -1650,9 +1648,11 @@ static int input_add_uevent_modalias_var(struct kobj_uevent_env *env,
 		return -ENOMEM;
 
 	len = input_print_modalias(&env->buf[env->buflen - 1],
-				   sizeof(env->buf) - env->buflen,
-				   dev, 0);
-	if (len >= (sizeof(env->buf) - env->buflen))
+				   (int)sizeof(env->buf) - env->buflen -
+					UEVENT_ENV_EXTRA_LEN,
+				   dev);
+	if (len >= ((int)sizeof(env->buf) - env->buflen -
+					UEVENT_ENV_EXTRA_LEN))
 		return -ENOMEM;
 
 	env->buflen += len;
@@ -1760,26 +1760,21 @@ static void input_dev_toggle(struct input_dev *dev, bool activate)
  */
 void input_reset_device(struct input_dev *dev)
 {
-	unsigned long flags;
-
-	mutex_lock(&dev->mutex);
-	spin_lock_irqsave(&dev->event_lock, flags);
+	guard(mutex)(&dev->mutex);
+	guard(spinlock_irqsave)(&dev->event_lock);
 
 	input_dev_toggle(dev, true);
 	if (input_dev_release_keys(dev))
 		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
-
-	spin_unlock_irqrestore(&dev->event_lock, flags);
-	mutex_unlock(&dev->mutex);
 }
 EXPORT_SYMBOL(input_reset_device);
 
 static int input_inhibit_device(struct input_dev *dev)
 {
-	mutex_lock(&dev->mutex);
+	guard(mutex)(&dev->mutex);
 
 	if (dev->inhibited)
-		goto out;
+		return 0;
 
 	if (dev->users) {
 		if (dev->close)
@@ -1788,54 +1783,50 @@ static int input_inhibit_device(struct input_dev *dev)
 			input_dev_poller_stop(dev->poller);
 	}
 
-	spin_lock_irq(&dev->event_lock);
-	input_mt_release_slots(dev);
-	input_dev_release_keys(dev);
-	input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
-	input_dev_toggle(dev, false);
-	spin_unlock_irq(&dev->event_lock);
+	scoped_guard(spinlock_irq, &dev->event_lock) {
+		input_mt_release_slots(dev);
+		input_dev_release_keys(dev);
+		input_handle_event(dev, EV_SYN, SYN_REPORT, 1);
+		input_dev_toggle(dev, false);
+	}
 
 	dev->inhibited = true;
 
-out:
-	mutex_unlock(&dev->mutex);
 	return 0;
 }
 
 static int input_uninhibit_device(struct input_dev *dev)
 {
-	int ret = 0;
+	int error;
 
-	mutex_lock(&dev->mutex);
+	guard(mutex)(&dev->mutex);
 
 	if (!dev->inhibited)
-		goto out;
+		return 0;
 
 	if (dev->users) {
 		if (dev->open) {
-			ret = dev->open(dev);
-			if (ret)
-				goto out;
+			error = dev->open(dev);
+			if (error)
+				return error;
 		}
 		if (dev->poller)
 			input_dev_poller_start(dev->poller);
 	}
 
 	dev->inhibited = false;
-	spin_lock_irq(&dev->event_lock);
-	input_dev_toggle(dev, true);
-	spin_unlock_irq(&dev->event_lock);
 
-out:
-	mutex_unlock(&dev->mutex);
-	return ret;
+	scoped_guard(spinlock_irq, &dev->event_lock)
+		input_dev_toggle(dev, true);
+
+	return 0;
 }
 
 static int input_dev_suspend(struct device *dev)
 {
 	struct input_dev *input_dev = to_input_dev(dev);
 
-	spin_lock_irq(&input_dev->event_lock);
+	guard(spinlock_irq)(&input_dev->event_lock);
 
 	/*
 	 * Keys that are pressed now are unlikely to be
@@ -1847,8 +1838,6 @@ static int input_dev_suspend(struct device *dev)
 	/* Turn off LEDs and sounds, if any are active. */
 	input_dev_toggle(input_dev, false);
 
-	spin_unlock_irq(&input_dev->event_lock);
-
 	return 0;
 }
 
@@ -1856,13 +1845,11 @@ static int input_dev_resume(struct device *dev)
 {
 	struct input_dev *input_dev = to_input_dev(dev);
 
-	spin_lock_irq(&input_dev->event_lock);
+	guard(spinlock_irq)(&input_dev->event_lock);
 
 	/* Restore state of LEDs and sounds, if any were active. */
 	input_dev_toggle(input_dev, true);
 
-	spin_unlock_irq(&input_dev->event_lock);
-
 	return 0;
 }
 
@@ -1870,7 +1857,7 @@ static int input_dev_freeze(struct device *dev)
 {
 	struct input_dev *input_dev = to_input_dev(dev);
 
-	spin_lock_irq(&input_dev->event_lock);
+	guard(spinlock_irq)(&input_dev->event_lock);
 
 	/*
 	 * Keys that are pressed now are unlikely to be
@@ -1879,8 +1866,6 @@ static int input_dev_freeze(struct device *dev)
 	if (input_dev_release_keys(input_dev))
 		input_handle_event(input_dev, EV_SYN, SYN_REPORT, 1);
 
-	spin_unlock_irq(&input_dev->event_lock);
-
 	return 0;
 }
 
@@ -1888,13 +1873,11 @@ static int input_dev_poweroff(struct device *dev)
 {
 	struct input_dev *input_dev = to_input_dev(dev);
 
-	spin_lock_irq(&input_dev->event_lock);
+	guard(spinlock_irq)(&input_dev->event_lock);
 
 	/* Turn off LEDs and sounds, if any are active. */
 	input_dev_toggle(input_dev, false);
 
-	spin_unlock_irq(&input_dev->event_lock);
-
 	return 0;
 }
 
@@ -1939,22 +1922,41 @@ struct input_dev *input_allocate_device(void)
 	struct input_dev *dev;
 
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
-	if (dev) {
-		dev->dev.type = &input_dev_type;
-		dev->dev.class = &input_class;
-		device_initialize(&dev->dev);
-		mutex_init(&dev->mutex);
-		spin_lock_init(&dev->event_lock);
-		timer_setup(&dev->timer, NULL, 0);
-		INIT_LIST_HEAD(&dev->h_list);
-		INIT_LIST_HEAD(&dev->node);
-
-		dev_set_name(&dev->dev, "input%lu",
-			     (unsigned long)atomic_inc_return(&input_no));
+	if (!dev)
+		return NULL;
 
-		__module_get(THIS_MODULE);
+	/*
+	 * Start with space for SYN_REPORT + 7 EV_KEY/EV_MSC events + 2 spare,
+	 * see input_estimate_events_per_packet(). We will tune the number
+	 * when we register the device.
+	 */
+	dev->max_vals = 10;
+	dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
+	if (!dev->vals) {
+		kfree(dev);
+		return NULL;
 	}
 
+	mutex_init(&dev->mutex);
+	spin_lock_init(&dev->event_lock);
+	timer_setup(&dev->timer, NULL, 0);
+	INIT_LIST_HEAD(&dev->h_list);
+	INIT_LIST_HEAD(&dev->node);
+
+	dev->dev.type = &input_dev_type;
+	dev->dev.class = &input_class;
+	device_initialize(&dev->dev);
+	/*
+	 * From this point on we can no longer simply "kfree(dev)", we need
+	 * to use input_free_device() so that device core properly frees its
+	 * resources associated with the input device.
+	 */
+
+	dev_set_name(&dev->dev, "input%lu",
+		     (unsigned long)atomic_inc_return(&input_no));
+
+	__module_get(THIS_MODULE);
+
 	return dev;
 }
 EXPORT_SYMBOL(input_allocate_device);
@@ -2168,7 +2170,7 @@ static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
 		mt_slots = dev->mt->num_slots;
 	} else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit)) {
 		mt_slots = dev->absinfo[ABS_MT_TRACKING_ID].maximum -
-			   dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1,
+			   dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1;
 		mt_slots = clamp(mt_slots, 2, 32);
 	} else if (test_bit(ABS_MT_POSITION_X, dev->absbit)) {
 		mt_slots = 2;
@@ -2216,18 +2218,16 @@ static void __input_unregister_device(struct input_dev *dev)
 
 	input_disconnect_device(dev);
 
-	mutex_lock(&input_mutex);
+	scoped_guard(mutex, &input_mutex) {
+		list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
+			handle->handler->disconnect(handle);
+		WARN_ON(!list_empty(&dev->h_list));
 
-	list_for_each_entry_safe(handle, next, &dev->h_list, d_node)
-		handle->handler->disconnect(handle);
-	WARN_ON(!list_empty(&dev->h_list));
+		timer_delete_sync(&dev->timer);
+		list_del_init(&dev->node);
 
-	del_timer_sync(&dev->timer);
-	list_del_init(&dev->node);
-
-	input_wakeup_procfs_readers();
-
-	mutex_unlock(&input_mutex);
+		input_wakeup_procfs_readers();
+	}
 
 	device_del(&dev->dev);
 }
@@ -2250,9 +2250,8 @@ static void devm_input_device_unregister(struct device *dev, void *res)
 static void input_repeat_key(struct timer_list *t)
 {
 	struct input_dev *dev = from_timer(dev, t, timer);
-	unsigned long flags;
 
-	spin_lock_irqsave(&dev->event_lock, flags);
+	guard(spinlock_irqsave)(&dev->event_lock);
 
 	if (!dev->inhibited &&
 	    test_bit(dev->repeat_key, dev->key) &&
@@ -2266,8 +2265,6 @@ static void input_repeat_key(struct timer_list *t)
 			mod_timer(&dev->timer, jiffies +
 					msecs_to_jiffies(dev->rep[REP_PERIOD]));
 	}
-
-	spin_unlock_irqrestore(&dev->event_lock, flags);
 }
 
 /**
@@ -2294,6 +2291,35 @@ bool input_device_enabled(struct input_dev *dev)
 }
 EXPORT_SYMBOL_GPL(input_device_enabled);
 
+static int input_device_tune_vals(struct input_dev *dev)
+{
+	struct input_value *vals;
+	unsigned int packet_size;
+	unsigned int max_vals;
+
+	packet_size = input_estimate_events_per_packet(dev);
+	if (dev->hint_events_per_packet < packet_size)
+		dev->hint_events_per_packet = packet_size;
+
+	max_vals = dev->hint_events_per_packet + 2;
+	if (dev->max_vals >= max_vals)
+		return 0;
+
+	vals = kcalloc(max_vals, sizeof(*vals), GFP_KERNEL);
+	if (!vals)
+		return -ENOMEM;
+
+	scoped_guard(spinlock_irq, &dev->event_lock) {
+		dev->max_vals = max_vals;
+		swap(dev->vals, vals);
+	}
+
+	/* Because of swap() above, this frees the old vals memory */
+	kfree(vals);
+
+	return 0;
+}
+
 /**
  * input_register_device - register device with input core
  * @dev: device to be registered
@@ -2321,7 +2347,6 @@ int input_register_device(struct input_dev *dev)
 {
 	struct input_devres *devres = NULL;
 	struct input_handler *handler;
-	unsigned int packet_size;
 	const char *path;
 	int error;
 
@@ -2349,16 +2374,9 @@ int input_register_device(struct input_dev *dev)
 	/* Make sure that bitmasks not mentioned in dev->evbit are clean. */
 	input_cleanse_bitmasks(dev);
 
-	packet_size = input_estimate_events_per_packet(dev);
-	if (dev->hint_events_per_packet < packet_size)
-		dev->hint_events_per_packet = packet_size;
-
-	dev->max_vals = dev->hint_events_per_packet + 2;
-	dev->vals = kcalloc(dev->max_vals, sizeof(*dev->vals), GFP_KERNEL);
-	if (!dev->vals) {
-		error = -ENOMEM;
+	error = input_device_tune_vals(dev);
+	if (error)
 		goto err_devres_free;
-	}
 
 	/*
 	 * If delay and period are pre-set by the driver, then autorepeating
@@ -2378,7 +2396,7 @@ int input_register_device(struct input_dev *dev)
 
 	error = device_add(&dev->dev);
 	if (error)
-		goto err_free_vals;
+		goto err_devres_free;
 
 	path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
 	pr_info("%s as %s\n",
@@ -2386,18 +2404,15 @@ int input_register_device(struct input_dev *dev)
 		path ? path : "N/A");
 	kfree(path);
 
-	error = mutex_lock_interruptible(&input_mutex);
-	if (error)
-		goto err_device_del;
-
-	list_add_tail(&dev->node, &input_dev_list);
+	error = -EINTR;
+	scoped_cond_guard(mutex_intr, goto err_device_del, &input_mutex) {
+		list_add_tail(&dev->node, &input_dev_list);
 
-	list_for_each_entry(handler, &input_handler_list, node)
-		input_attach_handler(dev, handler);
+		list_for_each_entry(handler, &input_handler_list, node)
+			input_attach_handler(dev, handler);
 
-	input_wakeup_procfs_readers();
-
-	mutex_unlock(&input_mutex);
+		input_wakeup_procfs_readers();
+	}
 
 	if (dev->devres_managed) {
 		dev_dbg(dev->dev.parent, "%s: registering %s with devres.\n",
@@ -2408,9 +2423,6 @@ int input_register_device(struct input_dev *dev)
 
 err_device_del:
 	device_del(&dev->dev);
-err_free_vals:
-	kfree(dev->vals);
-	dev->vals = NULL;
 err_devres_free:
 	devres_free(devres);
 	return error;
@@ -2443,6 +2455,26 @@ void input_unregister_device(struct input_dev *dev)
 }
 EXPORT_SYMBOL(input_unregister_device);
 
+static int input_handler_check_methods(const struct input_handler *handler)
+{
+	int count = 0;
+
+	if (handler->filter)
+		count++;
+	if (handler->events)
+		count++;
+	if (handler->event)
+		count++;
+
+	if (count > 1) {
+		pr_err("%s: only one event processing method can be defined (%s)\n",
+		       __func__, handler->name);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 /**
  * input_register_handler - register a new input handler
  * @handler: handler to be registered
@@ -2456,20 +2488,21 @@ int input_register_handler(struct input_handler *handler)
 	struct input_dev *dev;
 	int error;
 
-	error = mutex_lock_interruptible(&input_mutex);
+	error = input_handler_check_methods(handler);
 	if (error)
 		return error;
 
-	INIT_LIST_HEAD(&handler->h_list);
+	scoped_cond_guard(mutex_intr, return -EINTR, &input_mutex) {
+		INIT_LIST_HEAD(&handler->h_list);
 
-	list_add_tail(&handler->node, &input_handler_list);
+		list_add_tail(&handler->node, &input_handler_list);
 
-	list_for_each_entry(dev, &input_dev_list, node)
-		input_attach_handler(dev, handler);
+		list_for_each_entry(dev, &input_dev_list, node)
+			input_attach_handler(dev, handler);
 
-	input_wakeup_procfs_readers();
+		input_wakeup_procfs_readers();
+	}
 
-	mutex_unlock(&input_mutex);
 	return 0;
 }
 EXPORT_SYMBOL(input_register_handler);
@@ -2485,7 +2518,7 @@ void input_unregister_handler(struct input_handler *handler)
 {
 	struct input_handle *handle, *next;
 
-	mutex_lock(&input_mutex);
+	guard(mutex)(&input_mutex);
 
 	list_for_each_entry_safe(handle, next, &handler->h_list, h_node)
 		handler->disconnect(handle);
@@ -2494,8 +2527,6 @@ void input_unregister_handler(struct input_handler *handler)
 	list_del_init(&handler->node);
 
 	input_wakeup_procfs_readers();
-
-	mutex_unlock(&input_mutex);
 }
 EXPORT_SYMBOL(input_unregister_handler);
 
@@ -2515,22 +2546,89 @@ int input_handler_for_each_handle(struct input_handler *handler, void *data,
 				  int (*fn)(struct input_handle *, void *))
 {
 	struct input_handle *handle;
-	int retval = 0;
+	int retval;
 
-	rcu_read_lock();
+	guard(rcu)();
 
 	list_for_each_entry_rcu(handle, &handler->h_list, h_node) {
 		retval = fn(handle, data);
 		if (retval)
-			break;
+			return retval;
 	}
 
-	rcu_read_unlock();
-
-	return retval;
+	return 0;
 }
 EXPORT_SYMBOL(input_handler_for_each_handle);
 
+/*
+ * An implementation of input_handle's handle_events() method that simply
+ * invokes handler->event() method for each event one by one.
+ */
+static unsigned int input_handle_events_default(struct input_handle *handle,
+						struct input_value *vals,
+						unsigned int count)
+{
+	struct input_handler *handler = handle->handler;
+	struct input_value *v;
+
+	for (v = vals; v != vals + count; v++)
+		handler->event(handle, v->type, v->code, v->value);
+
+	return count;
+}
+
+/*
+ * An implementation of input_handle's handle_events() method that invokes
+ * handler->filter() method for each event one by one and removes events
+ * that were filtered out from the "vals" array.
+ */
+static unsigned int input_handle_events_filter(struct input_handle *handle,
+					       struct input_value *vals,
+					       unsigned int count)
+{
+	struct input_handler *handler = handle->handler;
+	struct input_value *end = vals;
+	struct input_value *v;
+
+	for (v = vals; v != vals + count; v++) {
+		if (handler->filter(handle, v->type, v->code, v->value))
+			continue;
+		if (end != v)
+			*end = *v;
+		end++;
+	}
+
+	return end - vals;
+}
+
+/*
+ * An implementation of input_handle's handle_events() method that does nothing.
+ */
+static unsigned int input_handle_events_null(struct input_handle *handle,
+					     struct input_value *vals,
+					     unsigned int count)
+{
+	return count;
+}
+
+/*
+ * Sets up appropriate handle->event_handler based on the input_handler
+ * associated with the handle.
+ */
+static void input_handle_setup_event_handler(struct input_handle *handle)
+{
+	struct input_handler *handler = handle->handler;
+
+	if (handler->filter)
+		handle->handle_events = input_handle_events_filter;
+	else if (handler->event)
+		handle->handle_events = input_handle_events_default;
+	else if (handler->events)
+		handle->handle_events = handler->events;
+	else
+		handle->handle_events = input_handle_events_null;
+}
+
 /**
  * input_register_handle - register a new input handle
  * @handle: handle to register
@@ -2546,26 +2644,22 @@ int input_register_handle(struct input_handle *handle)
 {
 	struct input_handler *handler = handle->handler;
 	struct input_dev *dev = handle->dev;
-	int error;
 
+	input_handle_setup_event_handler(handle);
 	/*
 	 * We take dev->mutex here to prevent race with
 	 * input_release_device().
 	 */
-	error = mutex_lock_interruptible(&dev->mutex);
-	if (error)
-		return error;
-
-	/*
-	 * Filters go to the head of the list, normal handlers
-	 * to the tail.
-	 */
-	if (handler->filter)
-		list_add_rcu(&handle->d_node, &dev->h_list);
-	else
-		list_add_tail_rcu(&handle->d_node, &dev->h_list);
-
-	mutex_unlock(&dev->mutex);
+	scoped_cond_guard(mutex_intr, return -EINTR, &dev->mutex) {
+		/*
+		 * Filters go to the head of the list, normal handlers
+		 * to the tail.
+		 */
+		if (handler->filter)
+			list_add_rcu(&handle->d_node, &dev->h_list);
+		else
+			list_add_tail_rcu(&handle->d_node, &dev->h_list);
+	}
 
 	/*
 	 * Since we are supposed to be called from ->connect()
@@ -2601,9 +2695,8 @@ void input_unregister_handle(struct input_handle *handle)
 	/*
 	 * Take dev->mutex to prevent race with input_release_device().
 	 */
-	mutex_lock(&dev->mutex);
-	list_del_rcu(&handle->d_node);
-	mutex_unlock(&dev->mutex);
+	scoped_guard(mutex, &dev->mutex)
+		list_del_rcu(&handle->d_node);
 
 	synchronize_rcu();
 }