Re: kernel/trace/trace_kprobe.c:952: warning: Excess function parameter 'args' description in '__kprobe_event_gen_cmd_start'

[Yujie Liu]

On Thu, Oct 19, 2023 at 09:22:07AM -0400, Steven Rostedt wrote:
> On Thu, 19 Oct 2023 04:33:41 +0800
> kernel test robot <lkp@xxxxxxxxx> wrote:
> 
> > All warnings (new ones prefixed by >>):
> > 
> > >> kernel/trace/trace_kprobe.c:952: warning: Excess function parameter 'args' description in '__kprobe_event_gen_cmd_start'
> > >> kernel/trace/trace_kprobe.c:1017: warning: Excess function parameter 'args' description in '__kprobe_event_add_fields'  
> > 
> > 
> > vim +952 kernel/trace/trace_kprobe.c
> > 
> >    929	
> >    930	/**
> >    931	 * __kprobe_event_gen_cmd_start - Generate a kprobe event command from arg list
> >    932	 * @cmd: A pointer to the dynevent_cmd struct representing the new event
> >    933	 * @name: The name of the kprobe event
> >    934	 * @loc: The location of the kprobe event
> >    935	 * @kretprobe: Is this a return probe?
> >    936	 * @args: Variable number of arg (pairs), one pair for each field
> >    937	 *
> >    938	 * NOTE: Users normally won't want to call this function directly, but
> >    939	 * rather use the kprobe_event_gen_cmd_start() wrapper, which automatically
> >    940	 * adds a NULL to the end of the arg list.  If this function is used
> >    941	 * directly, make sure the last arg in the variable arg list is NULL.
> >    942	 *
> >    943	 * Generate a kprobe event command to be executed by
> >    944	 * kprobe_event_gen_cmd_end().  This function can be used to generate the
> >    945	 * complete command or only the first part of it; in the latter case,
> >    946	 * kprobe_event_add_fields() can be used to add more fields following this.
> >    947	 *
> >    948	 * Return: 0 if successful, error otherwise.
> >    949	 */
> >    950	int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
> >    951					 const char *name, const char *loc, ...)
> >  > 952	{  
> 
> So what is the proper kerneldoc way to express variable length arguments?

Hi Steven, the fix patch is sent at [1] to fix this kernel-doc warning.

[1] https://lore.kernel.org/all/20231027041315.2613166-1-yujie.liu@xxxxxxxxx/

Best Regards,
Yujie