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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: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Dmitry Torokhov 2010-09-29 18:04:21 -07:00
parent 594d636320
commit 1966cb225c
1 changed files with 12 additions and 3 deletions
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15
drivers/char/sysrq.c
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@ -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[] = {