Re: [RFC PATCH v2 1/6] kcov: add per-task dataflow tracking for function arguments/return values

[Peter Zijlstra]

On Wed, Jun 03, 2026 at 07:43:28PM +0200, Yunseong Kim wrote:
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index e2f976c3301b..abd1a94589aa 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -2261,6 +2261,28 @@ config KCOV_SELFTEST
>  	  On test failure, causes the kernel to panic. Recommended to be
>  	  enabled, ensuring critical functionality works as intended.
>  
> +

^ This line...

> +config KCOV_DATAFLOW_ARGS
> +	bool "Enable KCOV dataflow: function argument capture"
> +	depends on KCOV
> +	depends on $(cc-option,-fsanitize-coverage=dataflow-args)
> +	help
> +	  Captures function arguments at entry via /sys/kernel/debug/kcov_dataflow.
> +	  Struct pointer arguments are auto-expanded using compiler DebugInfo
> +	  metadata, recording individual field values at runtime.
> +	  Enable per-module with: KCOV_DATAFLOW_file.o := y in the Makefile.
> +	  Requires clang with -fsanitize-coverage=dataflow-args support.
> +
> +config KCOV_DATAFLOW_RET
> +	bool "Enable KCOV dataflow: return value capture"
> +	depends on KCOV
> +	depends on $(cc-option,-fsanitize-coverage=dataflow-ret)
> +	help
> +	  Captures function return values via /sys/kernel/debug/kcov_dataflow.
> +	  Struct pointer returns are auto-expanded using compiler DebugInfo
> +	  metadata, recording individual field values at runtime.
> +	  Enable per-module with: KCOV_DATAFLOW_file.o := y in the Makefile.
> +	  Requires clang with -fsanitize-coverage=dataflow-ret support.

Probably wants to be here...

>  config DEBUG_AID_FOR_SYZBOT
>         bool "Additional debug code for syzbot"
>         default n
> 
> -- 
> 2.43.0
>