Re: [PATCH v6] kconfig: warn about malformed KCONFIG_PROBABILITY values

[Julian Braha <julianbraha@gmail.com>]

On 9/18/26 22:34, Dmitrii Tulnov wrote:
> randconfig checks the numeric range of each probability but does not
> validate where strtol() stops. For example, KCONFIG_PROBABILITY=50% is
> accepted as 50:0:0: the '%' is parsed repeatedly as zero. For the
> documented value 50, tristate y/m/n probabilities are 25%/25%/50%.
> With 50%, both y/m probabilities silently become zero, reducing the
> coverage of random configuration builds. Empty fields and extra fields
> are also accepted.
> 
> Warn when the value does not follow the documented decimal format. For
> malformed inputs whose parsed probabilities are in range, preserve the
> existing interpretation unless KCONFIG_WERROR is set. In that case, exit
> with an error before writing the configuration. Leading whitespace and
> signs are accepted by strtol(), but also trigger the warning because they
> are outside the documented format.
> 
> Keep the strtol() result as long until the range check. This rejects
> out-of-range values that narrowing to int previously made valid, such as
> 4294967296 becoming zero on a 64-bit host, regardless of KCONFIG_WERROR.
> 
> Add regression tests for one warning per malformed input, preserved
> configurations, KCONFIG_WERROR, out-of-range values, the supported
> probability formats, and the documented empty-value default.
> 
> Fixes: e43956e60769 ("kconfig: implement KCONFIG_PROBABILITY for randconfig")
> Assisted-by: LLM
> Signed-off-by: Dmitrii Tulnov <tulnov.dl@gmail.com>
Tested-by: Julian Braha <julianbraha@gmail.com>
Reviewed-by: Julian Braha <julianbraha@gmail.com>