Re: [RFC PATCH v2 01/14] kcov: add per-task dataflow tracking for function arguments/return values

Julian Braha <[email protected]> Fri, 12 Jun 2026 12:37:11 +0100
Newsgroups org.kernel.vger.workflows,dev.linux.lists.llvm,org.kernel.vger.linux-doc,org.kernel.vger.linux-kbuild,org.kernel.vger.linux-kernel,org.kernel.vger.linux-kselftest,org.kernel.vger.rust-for-linux,org.kvack.linux-mm
Message-ID <[email protected]>
On 6/11/26 17:21, Yunseong Kim wrote:
> +config KCOV_DATAFLOW_RET
> +	bool "Enable KCOV dataflow: return value capture"
> +	depends on KCOV
> +	depends on DEBUG_INFO
> +	depends on $(cc-option,-fsanitize-coverage=trace-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=trace-ret support.
> +
> +config KCOV_DATAFLOW_NO_INLINE
> +	bool "Disable inlining for dataflow-instrumented files"
> +	default n
In Kconfig, when you don't specify any default explicitly, it's
implicitly 'default n'.

I think either style (implicit or explicit) is fine and both are used
throughout the kernel, but is there any reason to make it explicit only
for KCOV_DATAFLOW_NO_INLINE, and implicit for the others?

- Julian Braha