Revert "Input: do not pass injected events back to the originating handler"

This reverts commit 5fdbe44d033d059cc56c2803e6b4dbd8cb4e5e39.

Apparently there exist userspace programs that expect to be able to
"loop back" and distribute to readers events written into
/dev/input/eventX and this change made for the benefit of SysRq
handler broke them. Now that SysRq uses alternative method to suppress
filtering of the events it re-injects we can safely revert this change.

Reported-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/input.c b/drivers/input/input.c
index f37da09..b8894a0 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -76,7 +76,6 @@
  * dev->event_lock held and interrupts disabled.
  */
 static void input_pass_event(struct input_dev *dev,
-			     struct input_handler *src_handler,
 			     unsigned int type, unsigned int code, int value)
 {
 	struct input_handler *handler;
@@ -95,15 +94,6 @@
 				continue;
 
 			handler = handle->handler;
-
-			/*
-			 * If this is the handler that injected this
-			 * particular event we want to skip it to avoid
-			 * filters firing again and again.
-			 */
-			if (handler == src_handler)
-				continue;
-
 			if (!handler->filter) {
 				if (filtered)
 					break;
@@ -133,7 +123,7 @@
 	if (test_bit(dev->repeat_key, dev->key) &&
 	    is_event_supported(dev->repeat_key, dev->keybit, KEY_MAX)) {
 
-		input_pass_event(dev, NULL, EV_KEY, dev->repeat_key, 2);
+		input_pass_event(dev, EV_KEY, dev->repeat_key, 2);
 
 		if (dev->sync) {
 			/*
@@ -142,7 +132,7 @@
 			 * Otherwise assume that the driver will send
 			 * SYN_REPORT once it's done.
 			 */
-			input_pass_event(dev, NULL, EV_SYN, SYN_REPORT, 1);
+			input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
 		}
 
 		if (dev->rep[REP_PERIOD])
@@ -175,7 +165,6 @@
 #define INPUT_PASS_TO_ALL	(INPUT_PASS_TO_HANDLERS | INPUT_PASS_TO_DEVICE)
 
 static int input_handle_abs_event(struct input_dev *dev,
-				  struct input_handler *src_handler,
 				  unsigned int code, int *pval)
 {
 	bool is_mt_event;
@@ -219,15 +208,13 @@
 	/* Flush pending "slot" event */
 	if (is_mt_event && dev->slot != input_abs_get_val(dev, ABS_MT_SLOT)) {
 		input_abs_set_val(dev, ABS_MT_SLOT, dev->slot);
-		input_pass_event(dev, src_handler,
-				 EV_ABS, ABS_MT_SLOT, dev->slot);
+		input_pass_event(dev, EV_ABS, ABS_MT_SLOT, dev->slot);
 	}
 
 	return INPUT_PASS_TO_HANDLERS;
 }
 
 static void input_handle_event(struct input_dev *dev,
-			       struct input_handler *src_handler,
 			       unsigned int type, unsigned int code, int value)
 {
 	int disposition = INPUT_IGNORE_EVENT;
@@ -280,8 +267,7 @@
 
 	case EV_ABS:
 		if (is_event_supported(code, dev->absbit, ABS_MAX))
-			disposition = input_handle_abs_event(dev, src_handler,
-							     code, &value);
+			disposition = input_handle_abs_event(dev, code, &value);
 
 		break;
 
@@ -339,7 +325,7 @@
 		dev->event(dev, type, code, value);
 
 	if (disposition & INPUT_PASS_TO_HANDLERS)
-		input_pass_event(dev, src_handler, type, code, value);
+		input_pass_event(dev, type, code, value);
 }
 
 /**
@@ -368,7 +354,7 @@
 
 		spin_lock_irqsave(&dev->event_lock, flags);
 		add_input_randomness(type, code, value);
-		input_handle_event(dev, NULL, type, code, value);
+		input_handle_event(dev, type, code, value);
 		spin_unlock_irqrestore(&dev->event_lock, flags);
 	}
 }
@@ -398,8 +384,7 @@
 		rcu_read_lock();
 		grab = rcu_dereference(dev->grab);
 		if (!grab || grab == handle)
-			input_handle_event(dev, handle->handler,
-					   type, code, value);
+			input_handle_event(dev, type, code, value);
 		rcu_read_unlock();
 
 		spin_unlock_irqrestore(&dev->event_lock, flags);
@@ -612,10 +597,10 @@
 		for (code = 0; code <= KEY_MAX; code++) {
 			if (is_event_supported(code, dev->keybit, KEY_MAX) &&
 			    __test_and_clear_bit(code, dev->key)) {
-				input_pass_event(dev, NULL, EV_KEY, code, 0);
+				input_pass_event(dev, EV_KEY, code, 0);
 			}
 		}
-		input_pass_event(dev, NULL, EV_SYN, SYN_REPORT, 1);
+		input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
 	}
 }
 
@@ -890,9 +875,9 @@
 	    !is_event_supported(old_keycode, dev->keybit, KEY_MAX) &&
 	    __test_and_clear_bit(old_keycode, dev->key)) {
 
-		input_pass_event(dev, NULL, EV_KEY, old_keycode, 0);
+		input_pass_event(dev, EV_KEY, old_keycode, 0);
 		if (dev->sync)
-			input_pass_event(dev, NULL, EV_SYN, SYN_REPORT, 1);
+			input_pass_event(dev, EV_SYN, SYN_REPORT, 1);
 	}
 
  out: