On 8/22/21 6:19 PM, 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_cb_data() derives from module_param_cb(), adding data
> param, and latter is redefined to use former.
>
> It calls __module_param_call_with_data(), which accepts 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.
>
> Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
> ---
> v6:
> . const void* data - <emil.l.velikov@xxxxxxxxx>
> . better macro names s/_cbd/_cb_data/, s/_wdata/_with_data/
> . more const, no cast - Willy
> ---
> include/linux/moduleparam.h | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
> index eed280fae433..b8871e514de5 100644
> --- a/include/linux/moduleparam.h
> +++ b/include/linux/moduleparam.h
> @@ -78,6 +78,7 @@ struct kernel_param {
> const struct kparam_string *str;
> const struct kparam_array *arr;
> };
> + const void *data;
> };
>
I wonder if kp->arg can just be used for all this and avoid this patch entirely?
define something like:
struct dd_bitmap_param {
int bitmap;
struct dyndbg_bitdesc *bitmap_arr;
};
and then just pass a pointer to it as 'arg' for module_param_cb? And then in
the get/set callbacks you can use kp->bitmap and kp->bitmap_arr.
Thanks,
-Jason
> extern const struct kernel_param __start___param[], __stop___param[];
> @@ -175,6 +176,9 @@ struct kparam_array
> #define module_param_cb(name, ops, arg, perm) \
> __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0)
>
> +#define module_param_cb_data(name, ops, arg, perm, data) \
> + __module_param_call_with_data(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0, 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)
> @@ -284,14 +288,17 @@ struct kparam_array
>
> /* This is the fundamental function for registering boot/module
> parameters. */
> -#define __module_param_call(prefix, name, ops, arg, perm, level, flags) \
> +#define __module_param_call(prefix, name, ops, arg, perm, level, flags) \
> + __module_param_call_with_data(prefix, name, ops, arg, perm, level, flags, NULL)
> +
> +#define __module_param_call_with_data(prefix, name, ops, arg, perm, level, flags, data) \
> /* Default value instead of permissions? */ \
> static const char __param_str_##name[] = prefix #name; \
> static struct kernel_param __moduleparam_const __param_##name \
> __used __section("__param") \
> __aligned(__alignof__(struct kernel_param)) \
> = { __param_str_##name, THIS_MODULE, ops, \
> - VERIFY_OCTAL_PERMISSIONS(perm), level, flags, { arg } }
> + VERIFY_OCTAL_PERMISSIONS(perm), level, flags, { arg }, data }
>
> /* Obsolete - use module_param_cb() */
> #define module_param_call(name, _set, _get, arg, perm) \
>
