Re: [rostedt-trace:for-next 58/100] samples/ftrace/ftrace-direct-multi.c:8:6: warning: no previous prototype for function 'my_direct_func'

Jiri Olsa
2021-11-01T14:43:02Z

On Mon, Nov 01, 2021 at 10:24:34AM -0400, Steven Rostedt wrote:
> On Mon, 1 Nov 2021 14:37:08 +0100
> Jiri Olsa <jolsa@redhat.com> wrote:
>
> > > If you fix the issue, kindly add following tag as appropriate
> > > Reported-by: kernel test robot <lkp@intel.com>
> > >
> > > All warnings (new ones prefixed by >>):
> > >
> > > >> samples/ftrace/ftrace-direct-multi.c:8:6: warning: no previous prototype for function 'my_direct_func' [-Wmissing-prototypes]
> > > void my_direct_func(unsigned long ip)
> > > ^
> > > samples/ftrace/ftrace-direct-multi.c:8:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> > > void my_direct_func(unsigned long ip)
> >
> > hum, that can actually be static.. I'll check
> >
>
> I'm not sure it can, because you call it from inline assembly, and the
> symbol may not be passed to the assembler.

yes, I just found that.. I actually could not add any input/output
arguments to asm, got a compilation error.. I think it's because
it's used outside any function

>
> It may work with some options, but may not for all.
>
> I think the best thing to do is just create a prototype to quiet the
> warning (with a comment).

ok, I'll send it.. should be on top of you for-next branch?

thanks,
jirka