[PATCH 4.11 46/84] gpiolib: fix filtering out unwanted events

Greg Kroah-Hartman
2017-07-03T13:48:31Z

From: Bartosz Golaszewski <brgl@bgdev.pl>

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>

---
drivers/gpio/gpiolib.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -708,7 +708,8 @@ static irqreturn_t lineevent_irq_thread(

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)