* Re: [PATCH] leds: leds-mt6323: Adjust return/parameter types in wled get/set callbacks
2023-06-22 16:12 [PATCH] leds: leds-mt6323: Adjust return/parameter types in wled get/set callbacks Nathan Chancellor
@ 2023-06-22 16:43 ` Nick Desaulniers
2023-06-22 16:54 ` Lee Jones
2023-06-23 8:04 ` AngeloGioacchino Del Regno
2023-06-26 9:10 ` Lee Jones
2 siblings, 1 reply; 5+ messages in thread
From: Nick Desaulniers @ 2023-06-22 16:43 UTC (permalink / raw)
To: Nathan Chancellor
Cc: lee, sean.wang, pavel, matthias.bgg, angelogioacchino.delregno,
trix, linux-leds, linux-arm-kernel, linux-mediatek, llvm, patches
On Thu, Jun 22, 2023 at 9:12 AM Nathan Chancellor <nathan@kernel.org> 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@kernel.org>
Thanks for the patch! Consider additionally having
mt6323_get_wled_brightness return LED_OFF rather than 0 in its
ternary.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
> drivers/leds/leds-mt6323.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/leds/leds-mt6323.c b/drivers/leds/leds-mt6323.c
> index e8fecfc2e90a..24f35bdb55fb 100644
> --- a/drivers/leds/leds-mt6323.c
> +++ b/drivers/leds/leds-mt6323.c
> @@ -76,7 +76,7 @@ struct mt6323_led {
> int id;
> struct mt6323_leds *parent;
> struct led_classdev cdev;
> - unsigned int current_brightness;
> + enum led_brightness current_brightness;
> };
>
> /**
> @@ -451,7 +451,7 @@ static int mtk_wled_hw_off(struct led_classdev *cdev)
> return 0;
> }
>
> -static unsigned int mt6323_get_wled_brightness(struct led_classdev *cdev)
> +static enum led_brightness mt6323_get_wled_brightness(struct led_classdev *cdev)
> {
> struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> struct mt6323_leds *leds = led->parent;
> @@ -471,7 +471,7 @@ static unsigned int mt6323_get_wled_brightness(struct led_classdev *cdev)
> }
>
> static int mt6323_wled_set_brightness(struct led_classdev *cdev,
> - unsigned int brightness)
> + enum led_brightness brightness)
> {
> struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> struct mt6323_leds *leds = led->parent;
>
> ---
> base-commit: 7bd932d9adbcc5c5370d968bdb0b00385606bf3a
> change-id: 20230621-mt6323-wled-wincompatible-function-pointer-types-strict-334f06d92ffb
>
> Best regards,
> --
> Nathan Chancellor <nathan@kernel.org>
>
>
--
Thanks,
~Nick Desaulniers
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] leds: leds-mt6323: Adjust return/parameter types in wled get/set callbacks
2023-06-22 16:43 ` Nick Desaulniers
@ 2023-06-22 16:54 ` Lee Jones
0 siblings, 0 replies; 5+ messages in thread
From: Lee Jones @ 2023-06-22 16:54 UTC (permalink / raw)
To: Nick Desaulniers
Cc: Nathan Chancellor, sean.wang, pavel, matthias.bgg,
angelogioacchino.delregno, trix, linux-leds, linux-arm-kernel,
linux-mediatek, llvm, patches
On Thu, 22 Jun 2023, Nick Desaulniers wrote:
> On Thu, Jun 22, 2023 at 9:12 AM Nathan Chancellor <nathan@kernel.org> 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@kernel.org>
>
> Thanks for the patch! Consider additionally having
> mt6323_get_wled_brightness return LED_OFF rather than 0 in its
> ternary.
https://elixir.bootlin.com/linux/latest/source/include/linux/leds.h#L32
Perhaps this is not relevant for this older driver though?
I'd really like some more information from Pavel on the history.
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
>
>
> > ---
> > drivers/leds/leds-mt6323.c | 6 +++---
> > 1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/leds/leds-mt6323.c b/drivers/leds/leds-mt6323.c
> > index e8fecfc2e90a..24f35bdb55fb 100644
> > --- a/drivers/leds/leds-mt6323.c
> > +++ b/drivers/leds/leds-mt6323.c
> > @@ -76,7 +76,7 @@ struct mt6323_led {
> > int id;
> > struct mt6323_leds *parent;
> > struct led_classdev cdev;
> > - unsigned int current_brightness;
> > + enum led_brightness current_brightness;
> > };
> >
> > /**
> > @@ -451,7 +451,7 @@ static int mtk_wled_hw_off(struct led_classdev *cdev)
> > return 0;
> > }
> >
> > -static unsigned int mt6323_get_wled_brightness(struct led_classdev *cdev)
> > +static enum led_brightness mt6323_get_wled_brightness(struct led_classdev *cdev)
> > {
> > struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> > struct mt6323_leds *leds = led->parent;
> > @@ -471,7 +471,7 @@ static unsigned int mt6323_get_wled_brightness(struct led_classdev *cdev)
> > }
> >
> > static int mt6323_wled_set_brightness(struct led_classdev *cdev,
> > - unsigned int brightness)
> > + enum led_brightness brightness)
> > {
> > struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> > struct mt6323_leds *leds = led->parent;
> >
> > ---
> > base-commit: 7bd932d9adbcc5c5370d968bdb0b00385606bf3a
> > change-id: 20230621-mt6323-wled-wincompatible-function-pointer-types-strict-334f06d92ffb
> >
> > Best regards,
> > --
> > Nathan Chancellor <nathan@kernel.org>
> >
> >
>
>
> --
> Thanks,
> ~Nick Desaulniers
--
Lee Jones [李琼斯]
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] leds: leds-mt6323: Adjust return/parameter types in wled get/set callbacks
2023-06-22 16:12 [PATCH] leds: leds-mt6323: Adjust return/parameter types in wled get/set callbacks Nathan Chancellor
2023-06-22 16:43 ` Nick Desaulniers
@ 2023-06-23 8:04 ` AngeloGioacchino Del Regno
2023-06-26 9:10 ` Lee Jones
2 siblings, 0 replies; 5+ messages in thread
From: AngeloGioacchino Del Regno @ 2023-06-23 8:04 UTC (permalink / raw)
To: Nathan Chancellor, lee
Cc: sean.wang, pavel, matthias.bgg, ndesaulniers, trix, linux-leds,
linux-arm-kernel, linux-mediatek, llvm, patches
Il 22/06/23 18:12, Nathan Chancellor ha scritto:
> 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@kernel.org>
leds need to deprecate said enumeration for real, since it's marked for
deprecation but, in the meanwhile, we can't have kCFI failures on this driver.
For this reason,
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cheers,
Angelo
> ---
> drivers/leds/leds-mt6323.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/leds/leds-mt6323.c b/drivers/leds/leds-mt6323.c
> index e8fecfc2e90a..24f35bdb55fb 100644
> --- a/drivers/leds/leds-mt6323.c
> +++ b/drivers/leds/leds-mt6323.c
> @@ -76,7 +76,7 @@ struct mt6323_led {
> int id;
> struct mt6323_leds *parent;
> struct led_classdev cdev;
> - unsigned int current_brightness;
> + enum led_brightness current_brightness;
> };
>
> /**
> @@ -451,7 +451,7 @@ static int mtk_wled_hw_off(struct led_classdev *cdev)
> return 0;
> }
>
> -static unsigned int mt6323_get_wled_brightness(struct led_classdev *cdev)
> +static enum led_brightness mt6323_get_wled_brightness(struct led_classdev *cdev)
> {
> struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> struct mt6323_leds *leds = led->parent;
> @@ -471,7 +471,7 @@ static unsigned int mt6323_get_wled_brightness(struct led_classdev *cdev)
> }
>
> static int mt6323_wled_set_brightness(struct led_classdev *cdev,
> - unsigned int brightness)
> + enum led_brightness brightness)
> {
> struct mt6323_led *led = container_of(cdev, struct mt6323_led, cdev);
> struct mt6323_leds *leds = led->parent;
>
> ---
> base-commit: 7bd932d9adbcc5c5370d968bdb0b00385606bf3a
> change-id: 20230621-mt6323-wled-wincompatible-function-pointer-types-strict-334f06d92ffb
>
> Best regards,
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] leds: leds-mt6323: Adjust return/parameter types in wled get/set callbacks
2023-06-22 16:12 [PATCH] leds: leds-mt6323: Adjust return/parameter types in wled get/set callbacks Nathan Chancellor
2023-06-22 16:43 ` Nick Desaulniers
2023-06-23 8:04 ` AngeloGioacchino Del Regno
@ 2023-06-26 9:10 ` Lee Jones
2 siblings, 0 replies; 5+ messages in thread
From: Lee Jones @ 2023-06-26 9:10 UTC (permalink / raw)
To: Nathan Chancellor
Cc: sean.wang, pavel, matthias.bgg, angelogioacchino.delregno,
ndesaulniers, trix, linux-leds, linux-arm-kernel, linux-mediatek,
llvm, patches
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@kernel.org>
> ---
> drivers/leds/leds-mt6323.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
Applied, thanks
--
Lee Jones [李琼斯]
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 5+ messages in thread