Include reason in error message when force loading is disabled.

Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com>
---
 kernel/module/main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/module/main.c b/kernel/module/main.c
index c66b26184936..a426bd8a18b5 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -1083,6 +1083,7 @@ int try_to_force_load(struct module *mod, const char *reason)
 	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
 	return 0;
 #else
+	pr_err("%s force load is not supported\n", reason);
 	return -ENOEXEC;
 #endif
 }
-- 
2.43.0

On 8/25/25 11:15 AM, Jinchao Wang wrote:
> Include reason in error message when force loading is disabled.
> 
> Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com>
> ---
>  kernel/module/main.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/kernel/module/main.c b/kernel/module/main.c
> index c66b26184936..a426bd8a18b5 100644
> --- a/kernel/module/main.c
> +++ b/kernel/module/main.c
> @@ -1083,6 +1083,7 @@ int try_to_force_load(struct module *mod, const char *reason)
>  	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
>  	return 0;
>  #else
> +	pr_err("%s force load is not supported\n", reason);
>  	return -ENOEXEC;
>  #endif
>  }

The module name is already available at all points where
try_to_force_load() is called, so the new error message should include
it.

Additionally, we should be careful about the message. In the case of the
init_module syscall, the missing modversions and vermagic could mean
that the data was deliberately stripped by kmod because the module was
inserted with --force, or it could mean that the module lacks this data
in the first place. In other words, it is not always the case that that
we're reaching this logic because of a force load.

My suggestion would be to use the following:

pr_err("%s: %s, force load is not supported\n", mod->name, reason);

-- 
Thanks,
Petr

On 8/26/25 17:33, Petr Pavlu wrote:
> On 8/25/25 11:15 AM, Jinchao Wang wrote:
>> Include reason in error message when force loading is disabled.
>>
>> Signed-off-by: Jinchao Wang <wangjinchao600@gmail.com>
>> ---
>>   kernel/module/main.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/kernel/module/main.c b/kernel/module/main.c
>> index c66b26184936..a426bd8a18b5 100644
>> --- a/kernel/module/main.c
>> +++ b/kernel/module/main.c
>> @@ -1083,6 +1083,7 @@ int try_to_force_load(struct module *mod, const char *reason)
>>   	add_taint_module(mod, TAINT_FORCED_MODULE, LOCKDEP_NOW_UNRELIABLE);
>>   	return 0;
>>   #else
>> +	pr_err("%s force load is not supported\n", reason);
>>   	return -ENOEXEC;
>>   #endif
>>   }
> 
> The module name is already available at all points where
> try_to_force_load() is called, so the new error message should include
> it.
> 
> Additionally, we should be careful about the message. In the case of the
> init_module syscall, the missing modversions and vermagic could mean
> that the data was deliberately stripped by kmod because the module was
> inserted with --force, or it could mean that the module lacks this data
> in the first place. In other words, it is not always the case that that
> we're reaching this logic because of a force load.
> 
> My suggestion would be to use the following:
> 
> pr_err("%s: %s, force load is not supported\n", mod->name, reason);
> 
Good suggestion. Thanks.

-- 
Best regards,
Jinchao