From 418ee8e91fe7fc90ffb6bce391304e084f77bce4 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 16 Oct 2017 11:32:29 +0200 Subject: gpiolib: only check line handle flags once There's no need to check the validity of handle request flags more than once, right after copying the data from user. Move the check out of the for loop and simplify the error path by bailing out before allocating any resources. Signed-off-by: Bartosz Golaszewski Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'drivers/gpio/gpiolib.c') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index ff46a1b6299e..58196be52b1e 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -444,12 +444,19 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) struct linehandle_state *lh; struct file *file; int fd, i, ret; + u32 lflags; if (copy_from_user(&handlereq, ip, sizeof(handlereq))) return -EFAULT; if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX)) return -EINVAL; + lflags = handlereq.flags; + + /* Return an error if an unknown flag is set */ + if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) + return -EINVAL; + lh = kzalloc(sizeof(*lh), GFP_KERNEL); if (!lh) return -ENOMEM; @@ -470,7 +477,6 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) /* Request each GPIO */ for (i = 0; i < handlereq.lines; i++) { u32 offset = handlereq.lineoffsets[i]; - u32 lflags = handlereq.flags; struct gpio_desc *desc; if (offset >= gdev->ngpio) { @@ -478,12 +484,6 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) goto out_free_descs; } - /* Return an error if a unknown flag is set */ - if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) { - ret = -EINVAL; - goto out_free_descs; - } - desc = &gdev->descs[offset]; ret = gpiod_request(desc, lh->label); if (ret) -- cgit