gpiolib: fix filtering out unwanted events

commit ad537b822577fcc143325786cd6ad50d7b9df31c upstream.

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.

Fixes: 61f922db7221 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 9215931..f2bb512 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -707,7 +707,8 @@ 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)