Re: __setup_param(), unique_id and vdso_setup

[Sam Ravnborg <sam@ravnborg.org>]

On Wed, May 06, 2009 at 03:24:21PM -0400, Robert P. J. Day wrote:
> 
>   just going through my outstanding list of kernel cleanup pedantry,
> and i was reminded of this from include/linux/init.h:
> 
> =====
> ...
> #define __setup(str, fn)                                        \
>         __setup_param(str, fn, fn, 0)
> 
> /* NOTE: fn is as per module_param, not __setup!  Emits warning if fn
>  * returns non-zero. */
> #define early_param(str, fn)                                    \
>         __setup_param(str, fn, fn, 1)
> ...
> =====
> 
>   in short, both invocations of __setup_param() use identical second
> and third parameters, and a tree-wide grep shows:
> 
> $ grep -rw __setup_param *
> arch/x86/vdso/vdso32-setup.c:__setup_param("vdso=", vdso32_setup, vdso_setup, 0);
> include/linux/init.h:#define __setup_param(str, unique_id, fn, early)                   \
> include/linux/init.h:   __setup_param(str, fn, fn, 0)
> include/linux/init.h:   __setup_param(str, fn, fn, 1)
> include/linux/init.h:#define __setup_param(str, unique_id, fn)  /* nothing */
> $
> 
>   so apart from that single exception involving "vdso", that macro
> could be simplified to just get rid of that third parameter.  is there
> something special about the vdso boot-time parm that *requires* it to
> be the only boot-time parm in the entire kernel to have a different
> unique id?  just curious.  or does that have to be preserved for
> out-of-tree builds?
No - so please go ahead and clean it up.

Thanks,
	Sam