On Thu, 22 Jun 2023, Nathan Chancellor wrote:
> Clang's kernel Control Flow Integrity (kCFI) is a compiler-based
> security mitigation that ensures the target of an indirect function call
> matches the expected type of the call and trapping if they do not match
> exactly. The warning -Wincompatible-function-pointer-types-strict aims
> to catch these issues at compile time, which reveals:
>
> drivers/leds/leds-mt6323.c:598:49: error: incompatible function pointer types assigning to 'int (*)(struct led_classdev *, enum led_brightness)' from 'int (struct led_classdev *, unsigned int)' [-Werror,-Wincompatible-function-pointer-types-strict]
> 598 | leds->led[reg]->cdev.brightness_set_blocking =
> | ^
> 599 | mt6323_wled_set_brightness;
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/leds/leds-mt6323.c:600:40: error: incompatible function pointer types assigning to 'enum led_brightness (*)(struct led_classdev *)' from 'unsigned int (struct led_classdev *)' [-Werror,-Wincompatible-function-pointer-types-strict]
> 600 | leds->led[reg]->cdev.brightness_get =
> | ^
> 601 | mt6323_get_wled_brightness;
> | ~~~~~~~~~~~~~~~~~~~~~~~~~~
> 2 errors generated.
>
> While 'unsigned int' is ABI compatible with 'enum led_brightness' (hence
> no warning from -Wincompatible-function-pointer-types) and the callers
> of these callbacks use/pass the values as 'unsigned int', the mismatch
> between the prototype and the called function will trip kCFI at runtime.
>
> Change the types in the implementations to match the prototypes, clearing
> up the warning and avoiding kCFI failures.
>
> Fixes: 9bb0a9e0626c ("leds: leds-mt6323: Add support for WLEDs and MT6332")
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> ---
> drivers/leds/leds-mt6323.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
Applied, thanks
--
Lee Jones [李琼斯]
