Re: [PATCH v5 2/9] moduleparam: add data member to struct kernel_param

From: Andy Shevchenko
Date: Fri Aug 13 2021 - 11:44:36 EST


On Fri, Aug 13, 2021 at 09:17:10AM -0600, Jim Cromie wrote:
> Add a const void* data member to the struct, to allow attaching
> private data that will be used soon by a setter method (via kp->data)
> to perform more elaborate actions.
>
> To attach the data at compile time, add new macros:
>
> module_param_cbd() derives from module_param_cb(), adding data param,
> and latter is redefined to use former.
>
> It calls __module_param_call_wdata(), which accepts a new data param
> and inits .data with it. Re-define __module_param_call() to use it.
>
> Use of this new data member will be rare, it might be worth redoing
> this as a separate/sub-type to de-bloat the base case.

...

> +#define module_param_cbd(name, ops, arg, perm, data) \
> + __module_param_call_wdata(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0, data)

Cryptic name. Moreover, inconsistent with the rest.
What about module_param_cb_data() ?

> #define module_param_cb_unsafe(name, ops, arg, perm) \
> __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, \
> KERNEL_PARAM_FL_UNSAFE)

(above left for the above comment)

...

> +#define __module_param_call_wdata(prefix, name, ops, arg, perm, level, flags, data) \

Similar __module_param_call_with_data()

--
With Best Regards,
Andy Shevchenko