From 1966cb225c6f9040ca163802cbd052c393d4448f Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 29 Sep 2010 18:04:21 -0700 Subject: [PATCH] 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 --- drivers/char/sysrq.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c index ef31bb81e843..f0ad694cc2eb 100644 --- a/drivers/char/sysrq.c +++ b/drivers/char/sysrq.c @@ -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[] = { -- 2.30.2