diff options
| author |   Kent Gibson <warthog618@gmail.com> | 2020-07-08 12:15:54 +0800 |
|---|---|---|
| committer |   Bartosz Golaszewski <bgolaszewski@baylibre.com> | 2020-07-12 10:22:01 +0200 |
| commit | 1bf7ba400173c3a134aae3187b550d79c2a5f585 (patch) | |
| tree | 6cf391acf47f72c23b6f99b280ae63a4a6166081 /drivers/gpio | |
| parent | gpiolib: cdev: fix minor race in GET_LINEINFO_WATCH (diff) | |
| download | wireguard-linux-1bf7ba400173c3a134aae3187b550d79c2a5f585.tar.xz wireguard-linux-1bf7ba400173c3a134aae3187b550d79c2a5f585.zip | |
gpiolib: cdev: remove recalculation of offset
Remove recalculation of offset from desc, where desc itself was calculated
from offset.
There is no benefit from the desc -> hwgpio conversion in this context.
The only implicit benefit of the offset -> desc -> hwgpio is
the range check in the offset -> desc, but where desc is required you
still get that, and where desc isn't required it is simpler to perform
the range check directly.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpiolib-cdev.c | 20 |
1 files changed, 7 insertions, 13 deletions
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index b2b26dc25051..c86fb9305681 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -832,7 +832,6 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) void __user *ip = (void __user *)arg; struct gpio_desc *desc; __u32 offset; - int hwgpio; /* We fail any subsequent ioctl():s when the chip is gone */ if (!gc) @@ -860,12 +859,11 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) return -EFAULT; + /* this doubles as a range check on line_offset */ desc = gpiochip_get_desc(gc, lineinfo.line_offset); if (IS_ERR(desc)) return PTR_ERR(desc); - hwgpio = gpio_chip_hwgpio(desc); - gpio_desc_to_lineinfo(desc, &lineinfo); if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) @@ -881,19 +879,18 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) return -EFAULT; + /* this doubles as a range check on line_offset */ desc = gpiochip_get_desc(gc, lineinfo.line_offset); if (IS_ERR(desc)) return PTR_ERR(desc); - hwgpio = gpio_chip_hwgpio(desc); - - if (test_and_set_bit(hwgpio, cdev->watched_lines)) + if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines)) return -EBUSY; gpio_desc_to_lineinfo(desc, &lineinfo); if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { - clear_bit(hwgpio, cdev->watched_lines); + clear_bit(lineinfo.line_offset, cdev->watched_lines); return -EFAULT; } @@ -902,13 +899,10 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) if (copy_from_user(&offset, ip, sizeof(offset))) return -EFAULT; - desc = gpiochip_get_desc(gc, offset); - if (IS_ERR(desc)) - return PTR_ERR(desc); - - hwgpio = gpio_chip_hwgpio(desc); + if (offset >= cdev->gdev->ngpio) + return -EINVAL; - if (!test_and_clear_bit(hwgpio, cdev->watched_lines)) + if (!test_and_clear_bit(offset, cdev->watched_lines)) return -EBUSY; return 0; |