From 1931479788c5e3c0396a0bde3606e517c64b9f95 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Wed, 26 Feb 2020 14:53:23 +0100 Subject: [PATCH] gpiolib: fix bitmap operations related to line event watching When operating on the bits of watched_lines bitmap, we're using desc_to_gpio() which returns the GPIO number from the global numberspace. This leads to all sorts of memory corruptions and invalid behavior. We should switch to using gpio_chip_hwgpio() instead. Fixes: 51c1064e82e7 ("gpiolib: add new ioctl() for monitoring changes in line info") Reported-by: Kent Gibson Signed-off-by: Bartosz Golaszewski Tested-by: Kent Gibson --- drivers/gpio/gpiolib.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 2068369..bc71f05 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1261,7 +1261,7 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return -EFAULT; if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) - set_bit(desc_to_gpio(desc), priv->watched_lines); + set_bit(gpio_chip_hwgpio(desc), priv->watched_lines); return 0; } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) { @@ -1276,7 +1276,7 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (IS_ERR(desc)) return PTR_ERR(desc); - clear_bit(desc_to_gpio(desc), priv->watched_lines); + clear_bit(gpio_chip_hwgpio(desc), priv->watched_lines); return 0; } return -EINVAL; @@ -1304,7 +1304,7 @@ static int lineinfo_changed_notify(struct notifier_block *nb, struct gpio_desc *desc = data; int ret; - if (!test_bit(desc_to_gpio(desc), priv->watched_lines)) + if (!test_bit(gpio_chip_hwgpio(desc), priv->watched_lines)) return NOTIFY_DONE; memset(&chg, 0, sizeof(chg)); -- 2.7.4