gpiolib: fix filtering out unwanted events

brgl · linusw · commit ad537b822577 · 2017-06-29T11:33:46.000+02:00
GPIOEVENT_REQUEST_BOTH_EDGES is not a single flag, but a binary OR of GPIOEVENT_REQUEST_RISING_EDGE and GPIOEVENT_REQUEST_FALLING_EDGE. The expression 'le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES' we'll get evaluated to true even if only one event type was requested. Fix it by checking both RISING & FALLING flags explicitly. Cc: stable@vger.kernel.org Fixes: 61f922d ("gpio: userspace ABI for reading GPIO line events") Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
@@ -708,7 +708,8 @@ static irqreturn_t lineevent_irq_thread(int irq, void *p)
 
 	ge.timestamp = ktime_get_real_ns();
 
-	if (le->eflags & GPIOEVENT_REQUEST_BOTH_EDGES) {
+	if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE
+	    && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) {
 		int level = gpiod_get_value_cansleep(le->desc);
 
 		if (level)
