Re: [PATCH] clocksource/drivers/timer-mediatek: Fix "no-cfi indirect call" warning

[Nathan Chancellor <nathan@kernel.org>]

On Sun, Nov 01, 2026 at 10:55:31AM +0100, Luca Leonardo Scorcia wrote:
> After converting the driver to OF probing, kernel-test-robot reported the
> following new warning:
> 
> vmlinux.o: warning: objtool: mtk_timer_probe+0x23: no-cfi indirect call!
> 
> This occurs because of_device_get_match_data() returns NULL when
> CONFIG_OF is disabled, which results in LLVM dropping the kCFI setup
> since it knows that there is no valid target for this call. Adding a
> check for a NULL timer_init avoids the warning and it makes the probe
> more robust since of_device_get_match_data() could return NULL even
> when CONFIG_OF=y.
> 
> Fixes: 7a097aba7255 ("clocksource/drivers/timer-mediatek: Convert to OF probing")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202610290223.iOEGeDs2-lkp@intel.com/
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Luca Leonardo Scorcia <l.scorcia@gmail.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  drivers/clocksource/timer-mediatek.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/clocksource/timer-mediatek.c b/drivers/clocksource/timer-mediatek.c
> index 842d6ee4259e..e772f5fe8742 100644
> --- a/drivers/clocksource/timer-mediatek.c
> +++ b/drivers/clocksource/timer-mediatek.c
> @@ -353,6 +353,9 @@ static int mtk_timer_probe(struct platform_device *pdev)
>  	int (*timer_init)(struct platform_device *pdev);
>  
>  	timer_init = of_device_get_match_data(&pdev->dev);
> +	if (!timer_init)
> +		return -ENODEV;
> +
>  	return timer_init(pdev);
>  }
>  
> -- 
> 2.43.0
> 

-- 
Cheers,
Nathan