diff options
author | Kent Gibson <warthog618@gmail.com> | 2020-12-28 00:10:40 +0800 |
---|---|---|
committer | Bartosz Golaszewski <bgolaszewski@baylibre.com> | 2021-01-03 16:32:21 +0100 |
commit | 2e202ad873365513c6ad72e29a531071dffa498a (patch) | |
tree | 3e2e0f917ab66ded76ff46f7ddd47b783400e784 /drivers/gpio/gpiolib-cdev.c | |
parent | 5c8fe583cce542aa0b84adc939ce85293de36e5e (diff) | |
download | linux-2e202ad873365513c6ad72e29a531071dffa498a.tar.bz2 |
gpiolib: cdev: fix frame size warning in gpio_ioctl()
The kernel test robot reports the following warning in [1]:
drivers/gpio/gpiolib-cdev.c: In function 'gpio_ioctl':
>>drivers/gpio/gpiolib-cdev.c:1437:1: warning: the frame size of 1040 bytes is larger than 1024 bytes [-Wframe-larger-than=]
Refactor gpio_ioctl() to handle each ioctl in its own helper function
and so reduce the variables stored on the stack to those explicitly
required to service the ioctl at hand.
The lineinfo_get_v1() helper handles both the GPIO_GET_LINEINFO_IOCTL
and GPIO_GET_LINEINFO_WATCH_IOCTL, as per the corresponding v2
implementation - lineinfo_get().
[1] https://lore.kernel.org/lkml/202012270910.VW3qc1ER-lkp@intel.com/
Fixes: aad955842d1c ("gpiolib: cdev: support GPIO_V2_GET_LINEINFO_IOCTL and GPIO_V2_GET_LINEINFO_WATCH_IOCTL")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Diffstat (limited to 'drivers/gpio/gpiolib-cdev.c')
-rw-r--r-- | drivers/gpio/gpiolib-cdev.c | 145 |
1 files changed, 73 insertions, 72 deletions
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 12b679ca552c..1a7b51163528 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -1979,6 +1979,21 @@ struct gpio_chardev_data { #endif }; +static int chipinfo_get(struct gpio_chardev_data *cdev, void __user *ip) +{ + struct gpio_device *gdev = cdev->gdev; + struct gpiochip_info chipinfo; + + memset(&chipinfo, 0, sizeof(chipinfo)); + + strscpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name)); + strscpy(chipinfo.label, gdev->label, sizeof(chipinfo.label)); + chipinfo.lines = gdev->ngpio; + if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) + return -EFAULT; + return 0; +} + #ifdef CONFIG_GPIO_CDEV_V1 /* * returns 0 if the versions match, else the previously selected ABI version @@ -1993,6 +2008,41 @@ static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata, return abiv; } + +static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip, + bool watch) +{ + struct gpio_desc *desc; + struct gpioline_info lineinfo; + struct gpio_v2_line_info lineinfo_v2; + + if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) + return -EFAULT; + + /* this doubles as a range check on line_offset */ + desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.line_offset); + if (IS_ERR(desc)) + return PTR_ERR(desc); + + if (watch) { + if (lineinfo_ensure_abi_version(cdev, 1)) + return -EPERM; + + if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines)) + return -EBUSY; + } + + gpio_desc_to_lineinfo(desc, &lineinfo_v2); + gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo); + + if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { + if (watch) + clear_bit(lineinfo.line_offset, cdev->watched_lines); + return -EFAULT; + } + + return 0; +} #endif static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip, @@ -2030,6 +2080,22 @@ static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip, return 0; } +static int lineinfo_unwatch(struct gpio_chardev_data *cdev, void __user *ip) +{ + __u32 offset; + + if (copy_from_user(&offset, ip, sizeof(offset))) + return -EFAULT; + + if (offset >= cdev->gdev->ngpio) + return -EINVAL; + + if (!test_and_clear_bit(offset, cdev->watched_lines)) + return -EBUSY; + + return 0; +} + /* * gpio_ioctl() - ioctl handler for the GPIO chardev */ @@ -2037,80 +2103,24 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct gpio_chardev_data *cdev = file->private_data; struct gpio_device *gdev = cdev->gdev; - struct gpio_chip *gc = gdev->chip; void __user *ip = (void __user *)arg; - __u32 offset; /* We fail any subsequent ioctl():s when the chip is gone */ - if (!gc) + if (!gdev->chip) return -ENODEV; /* Fill in the struct and pass to userspace */ if (cmd == GPIO_GET_CHIPINFO_IOCTL) { - struct gpiochip_info chipinfo; - - memset(&chipinfo, 0, sizeof(chipinfo)); - - strscpy(chipinfo.name, dev_name(&gdev->dev), - sizeof(chipinfo.name)); - strscpy(chipinfo.label, gdev->label, - sizeof(chipinfo.label)); - chipinfo.lines = gdev->ngpio; - if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) - return -EFAULT; - return 0; + return chipinfo_get(cdev, ip); #ifdef CONFIG_GPIO_CDEV_V1 - } else if (cmd == GPIO_GET_LINEINFO_IOCTL) { - struct gpio_desc *desc; - struct gpioline_info lineinfo; - struct gpio_v2_line_info lineinfo_v2; - - 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); - - gpio_desc_to_lineinfo(desc, &lineinfo_v2); - gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo); - - if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) - return -EFAULT; - return 0; } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) { return linehandle_create(gdev, ip); } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) { return lineevent_create(gdev, ip); - } else if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) { - struct gpio_desc *desc; - struct gpioline_info lineinfo; - struct gpio_v2_line_info lineinfo_v2; - - 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); - - if (lineinfo_ensure_abi_version(cdev, 1)) - return -EPERM; - - if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines)) - return -EBUSY; - - gpio_desc_to_lineinfo(desc, &lineinfo_v2); - gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo); - - if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { - clear_bit(lineinfo.line_offset, cdev->watched_lines); - return -EFAULT; - } - - return 0; + } else if (cmd == GPIO_GET_LINEINFO_IOCTL || + cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) { + return lineinfo_get_v1(cdev, ip, + cmd == GPIO_GET_LINEINFO_WATCH_IOCTL); #endif /* CONFIG_GPIO_CDEV_V1 */ } else if (cmd == GPIO_V2_GET_LINEINFO_IOCTL || cmd == GPIO_V2_GET_LINEINFO_WATCH_IOCTL) { @@ -2119,16 +2129,7 @@ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) } else if (cmd == GPIO_V2_GET_LINE_IOCTL) { return linereq_create(gdev, ip); } else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) { - if (copy_from_user(&offset, ip, sizeof(offset))) - return -EFAULT; - - if (offset >= cdev->gdev->ngpio) - return -EINVAL; - - if (!test_and_clear_bit(offset, cdev->watched_lines)) - return -EBUSY; - - return 0; + return lineinfo_unwatch(cdev, ip); } return -EINVAL; } |