[PATCH 0/8] gpiolib: sanitize return values of callbacks

[Bartosz Golaszewski <brgl@xxxxxxxx>]

We've had instances of drivers returning invalid values from gpio_chip
calbacks. In several cases these return values would be propagated to
user-space and confuse programs that only expect 0 or negative errnos
from ioctl()s. Let's sanitize the return values of callbacks and make
sure we don't allow anyone see invalid ones.

The first patch checks the return values of get_direction() in kernel
where needed and is a backportable fix.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
---
Bartosz Golaszewski (8):
      gpiolib: check the return value of gpio_chip::get_direction()
      gpiolib: sanitize the return value of gpio_chip::request()
      gpiolib: sanitize the return value of gpio_chip::set_config()
      gpiolib: sanitize the return value of gpio_chip::get()
      gpiolib: sanitize the return value of gpio_chip::get_multiple()
      gpiolib: sanitize the return value of gpio_chip::direction_output()
      gpiolib: sanitize the return value of gpio_chip::direction_input()
      gpiolib: sanitize the return value of gpio_chip::get_direction()

 drivers/gpio/gpiolib.c      | 144 +++++++++++++++++++++++++++++++++++---------
 include/linux/gpio/driver.h |   6 +-
 2 files changed, 120 insertions(+), 30 deletions(-)
---
base-commit: a13f6e0f405ed0d3bcfd37c692c7d7fa3c052154
change-id: 20241212-gpio-sanitize-retvals-f5f4e0d6f57d

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>