From 39243ee771666e02201ba89c1d76fdc28e9cf681 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 15 Jun 2016 22:57:38 +0200 Subject: [PATCH] gpio: make sure gpiod_to_irq() returns negative on NULL desc commit 54d77198fdfbc4f0fe11b4252c1d9c97d51a3264 ("gpio: bail out silently on NULL descriptors") doesn't work for gpiod_to_irq(): drivers assume that NULL descriptors will give negative IRQ numbers in return. It has been pointed out that returning 0 is NO_IRQ and that drivers should be amended to treat this as an error, but that is for the longer term: now let us repair the semantics. Cc: Maxime Ripard Reported-by: Hans de Goede Tested-by: Hans de Goede Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 58d822d7e8da..f39bf05993e7 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2056,7 +2056,14 @@ int gpiod_to_irq(const struct gpio_desc *desc) struct gpio_chip *chip; int offset; - VALIDATE_DESC(desc); + /* + * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics + * requires this function to not return zero on an invalid descriptor + * but rather a negative error number. + */ + if (!desc || !desc->gdev || !desc->gdev->chip) + return -EINVAL; + chip = desc->gdev->chip; offset = gpio_chip_hwgpio(desc); if (chip->to_irq) { -- 2.30.2