[LTP] [PATCH] lib: tst_kconfig: Add runtime checks

[Cyril Hrubis]

Hi!
> It would be great to have a description for the feature:
> 
> Something maybe like:
> 
>  "Currently, LTP Kconfig parsing logic only checks if a feature was
>   enabled during kernel compilation (e.g., CONFIG_USER_NS=y). However,
>   some kernel features can be compiled in but disabled at runtime via
>   kernel command-line parameter or sysctls. When this happens, tests
>   relying on these Kconfig variables attempt to run and fail, rather
>   than being gracefully skipped.
>   
>   This patch introduces a runtime check mechanism for Kconfig variables.
>   When a monitored CONFIG_* variable is parsed as 'y' or 'm', the framework
>   now executes an associated runtime check function. If the runtime check
>   fails, the framework logs an info message and internally overrides the
>   variable's state to 'n'. This allows the existing LTP dependency logic
>   to properly skip tests that require the disabled feature."

Ah, sorry I've fixed the code but kept the description single line, I
will fix that.

> Also, add test_kconfig04.c in newlib_tests/ to verify this works?

I've added a new config variable to newlib_tests/test_kconfig.c (it does
not show in the output unless you boot with namespaces disabled).

If you do and run it:

$ ./test_kconfig
tst_kconfig.c:90: TINFO: Parsing kernel config '/lib/modules/6.16.0/build/.config'
tst_kconfig.c:138: TINFO: CONFIG_USER_NS=y present but disabled at runtime
...
tst_kconfig.c:566: TINFO: Constraint 'CONFIG_USER_NS' not satisfied!
tst_kconfig.c:512: TINFO: Variables:
tst_kconfig.c:530: TINFO:  CONFIG_USER_NS=n
tst_test.c:1461: TCONF: Aborting due to unsuitable kernel config, see above!


-- 
Cyril Hrubis
chrubis@suse.cz