Commit 1966cb22 authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

Input: sysrq - add locking to sysrq_filter() 



Similarly to the keyboard handler, we are called by different input
devices and thus need to add spinlock if we want to maintain our
state properly.

Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 594d6363

drivers/char/sysrq.c

+12 −3
Original line number Diff line number Diff line
@@ -566,10 +566,16 @@ static const unsigned char sysrq_xlate[KEY_MAX + 1] = 
static bool sysrq_down;

static int sysrq_alt_use;

static int sysrq_alt;

static DEFINE_SPINLOCK(sysrq_event_lock);



static bool sysrq_filter(struct input_handle *handle, unsigned int type,

		         unsigned int code, int value)

{

	bool suppress;



	/* We are called with interrupts disabled, just take the lock */

	spin_lock(&sysrq_event_lock);



	if (type != EV_KEY)

		goto out;
@@ -601,7 +607,10 @@ static bool sysrq_filter(struct input_handle *handle, unsigned int type, 
	}



out:

	return sysrq_down;

	suppress = sysrq_down;

	spin_unlock(&sysrq_event_lock);



	return suppress;

}



static int sysrq_connect(struct input_handler *handler,
@@ -652,8 +661,8 @@ static void sysrq_disconnect(struct input_handle *handle) 
}



/*

 * We are matching on KEY_LEFTALT insteard of KEY_SYSRQ because not all

 * keyboards have SysRq ikey predefined and so user may add it to keymap

 * We are matching on KEY_LEFTALT instead of KEY_SYSRQ because not all

 * keyboards have SysRq key predefined and so user may add it to keymap

 * later, but we expect all such keyboards to have left alt.

 */

static const struct input_device_id sysrq_ids[] = {