[LTP] [PATCH 04/17] lib: tst_kconfig: Add module presence checks

[Li Wang]

On Thu, Apr 02, 2026 at 02:13:43PM +0200, Cyril Hrubis wrote:
> The .needs_kconfig and .needs_drivers fields in the tst_test structure
> had overlaping functionality. Both were checking if a functionality was
> build in into the kernel or compiled as a driver. Similarily to the
> runtime checks added to tst_kconfig modules can be build but packaged
> into separate packages and may not be installed on the system even if
> corresponding config option was set to 'm'.
> 
> This commit adds a mapping table from CONFIG options to module names for
> the modules we care about. Most of the time the mapping is trivial, but
> some CONFIG options does not really match the module name, hence we need
> a mapping. We may also be able to generate the table from kernel config
> infrastructure later on, but at this point the number of options is
> small enough to be manageable by hand editing.
> 
> Once we have that mapping we can run aditional check for a module
> presence if the confing option was set to 'm' and if mapping exists in
> order to disable the config option when the module was not found.
> 
> Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
> ---
>  lib/tst_kconfig.c | 41 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 41 insertions(+)
> 
> diff --git a/lib/tst_kconfig.c b/lib/tst_kconfig.c
> index 52dd6d726..c5dd97a45 100644
> --- a/lib/tst_kconfig.c
> +++ b/lib/tst_kconfig.c
> @@ -144,6 +144,46 @@ static void runtime_check(struct tst_kconfig_var *var)
>  	}
>  }
>  
> +static struct module_check {
> +	const char *config;
> +	const char *module_name;
> +} module_checks[] = {
> +	{"CONFIG_KVM", "kvm"},
> +	{"CONFIG_ZRAM", "zram"},
> +	{"CONFIG_SQUASHFS", "squashfs"},
> +	{"CONFIG_BLK_DEV_LOOP", "loop"},
> +	{"CONFIG_TUN", "tun"},
> +	{"CONFIG_BLK_DEV_RAM", "brd"},
> +	{"CONFIG_HWPOISON_INJECT", "hwpoison_inject"},
> +	{"CONFIG_QFMT_V2", "quota_v2"},
> +	{"CONFIG_INPUT_UINPUT", "uinput"},
> +	{"CONFIG_DUMMY", "dummy"},
> +	{"CONFIG_CAN_VCAN", "vcan"},
> +	{"CONFIG_CAN_RAW", "can-raw"},
> +	{"CONFIG_CAN_BCM", "can-bcm"},
> +	{"CONFIG_IP_SCTP", "sctp"},
> +	{}
> +};

Maybe rename the struct to:

	static struct config_module_map {
		const char *config;
		const char *module_name;
	} config_module_maps[] = {
		...
	}

And rename 'struct runtime_check' to:

	static struct config_runtime_map {
		const char *config;
		bool (*runtime_check)(void);
	} config_runtime_maps[] = {
		...
	};

This is a tiny nit; I don't have strong opinions.

>  static inline int kconfig_parse_line(const char *line,
>                                       struct tst_kconfig_var *vars,
>                                       unsigned int vars_len)
> @@ -222,6 +262,7 @@ out:
>  			case 'm':
>  				vars[i].choice = 'm';
>  				runtime_check(&vars[i]);
> +				module_check(&vars[i]);

Then rename the two functions to:

    kconfig_runtime_check()
    kconfig_module_check()

Because in tst_kconfig.c most function contains "kconfig_" string.

-- 
Regards,
Li Wang