Re: [PATCH] module: Allow to disable modsign in kernel cmdline

[Randy Dunlap]

On 4/27/20 8:43 PM, Tianjia Zhang wrote:
> This change allows to disable modsign completely at the beginning,
> and turn off by set the kernel cmdline `no_modsig_enforce` when
> CONFIG_MODULE_SIG_FORCE is enabled.
> 
> Yet another change allows to always show the current status of
> modsign through `/sys/module/module/parameters/sig_enforce`.
> 
> Signed-off-by: Jia Zhang <zhang.jia@xxxxxxxxxxxxxxxxx>
> Signed-off-by: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx>
> ---
>  kernel/module.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/kernel/module.c b/kernel/module.c
> index 646f1e2330d2..0e68e1286377 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -269,6 +269,14 @@ static void module_assert_mutex_or_preempt(void)
>  
>  static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
>  module_param(sig_enforce, bool_enable_only, 0644);
> +#ifdef CONFIG_MODULE_SIG_FORCE
> +static int __init set_no_modsig_enforce(char *str)
> +{
> +	sig_enforce = false;
> +	return 1;
> +}
> +__setup("no_modsig_enforce", set_no_modsig_enforce);
> +#endif /* !CONFIG_MODULE_SIG_FORCE */
>  
>  /*
>   * Export sig_enforce kernel cmdline parameter to allow other subsystems rely
> 

Hi,
Please document this cmdline option, probably in
Documentation/admin-guide/kernel-parameters.txt.

thanks.

-- 
~Randy