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Subject: Re: [PATCH] module: Allow to disable modsign in kernel cmdline
To:     Randy Dunlap <rdunlap@infradead.org>, jeyu@kernel.org
Cc:     linux-kernel@vger.kernel.org
References: <20200428034310.44035-1-tianjia.zhang@linux.alibaba.com>
 <713892bf-ffe8-8cfd-b2c5-7090626c02fe@infradead.org>
From:   Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Message-ID: <546660e1-6128-95a1-fbfe-10a9d3b0f6fb@linux.alibaba.com>
Date:   Tue, 28 Apr 2020 13:03:49 +0800
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On 2020/4/28 11:47, Randy Dunlap wrote:
> 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@linux.alibaba.com>
>> Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
>> ---
>>   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.
> 

Thanks for your information, I will submit a v2 patch.

Thanks and best,
Tianjia