Commit 92a3a587 authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

Input: cleanse capabilities bits before registering device 



To avoid showing garbage in capability bits, zero out bitmasks absent
from dev->evbit in case driver inadvertently leaves some garbage there.

Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 4f93df40

drivers/input/input.c

+22 −0
Original line number Diff line number Diff line
@@ -1497,6 +1497,25 @@ void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int 
}

EXPORT_SYMBOL(input_set_capability);



#define INPUT_CLEANSE_BITMASK(dev, type, bits)				\

	do {								\

		if (!test_bit(EV_##type, dev->evbit))			\

			memset(dev->bits##bit, 0,			\

				sizeof(dev->bits##bit));		\

	} while (0)



static void input_cleanse_bitmasks(struct input_dev *dev)

{

	INPUT_CLEANSE_BITMASK(dev, KEY, key);

	INPUT_CLEANSE_BITMASK(dev, REL, rel);

	INPUT_CLEANSE_BITMASK(dev, ABS, abs);

	INPUT_CLEANSE_BITMASK(dev, MSC, msc);

	INPUT_CLEANSE_BITMASK(dev, LED, led);

	INPUT_CLEANSE_BITMASK(dev, SND, snd);

	INPUT_CLEANSE_BITMASK(dev, FF, ff);

	INPUT_CLEANSE_BITMASK(dev, SW, sw);

}



/**

 * input_register_device - register device with input core

 * @dev: device to be registered
@@ -1522,6 +1541,9 @@ int input_register_device(struct input_dev *dev) 
	/* KEY_RESERVED is not supposed to be transmitted to userspace. */

	__clear_bit(KEY_RESERVED, dev->keybit);



	/* Make sure that bitmasks not mentioned in dev->evbit are clean. */

	input_cleanse_bitmasks(dev);



	/*

	 * If delay and period are pre-set by the driver, then autorepeating

	 * is handled by the driver itself and we don't do it in input.c.