Re: arch/sh/boot/compressed/misc.c:118:6: warning: no previous prototype for 'arch_ftrace_ops_list_func'

[Yujie Liu <yujie.liu@intel.com>]

On Mon, Oct 30, 2023 at 06:37:22PM -0400, Steven Rostedt wrote:
> On Tue, 31 Oct 2023 06:15:04 +0800
> kernel test robot <lkp@intel.com> wrote:
> 
> > Hi Steven,
> > 
> > FYI, the error/warning still remains.
> > 
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   14ab6d425e80674b6a0145f05719b11e82e64824
> > commit: 17b251a290ba84a0c2c5c82df9596cb2e7207ca6 ftrace/sh: Add arch_ftrace_ops_list_func stub to have compressed image still link
> > date:   2 years ago
> > config: sh-allnoconfig (https://download.01.org/0day-ci/archive/20231031/202310310611.5RteDpO7-lkp@intel.com/config)
> > compiler: sh4-linux-gcc (GCC) 13.2.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231031/202310310611.5RteDpO7-lkp@intel.com/reproduce)
> > 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202310310611.5RteDpO7-lkp@intel.com/
> > 
> > All warnings (new ones prefixed by >>):
> > 
> >    arch/sh/boot/compressed/misc.c:109:6: warning: no previous prototype for '__stack_chk_fail' [-Wmissing-prototypes]
> >      109 | void __stack_chk_fail(void)
> >          |      ^~~~~~~~~~~~~~~~
> >    arch/sh/boot/compressed/misc.c:115:6: warning: no previous prototype for 'ftrace_stub' [-Wmissing-prototypes]
> >      115 | void ftrace_stub(void)
> >          |      ^~~~~~~~~~~
> > >> arch/sh/boot/compressed/misc.c:118:6: warning: no previous prototype for 'arch_ftrace_ops_list_func' [-Wmissing-prototypes]  
> >      118 | void arch_ftrace_ops_list_func(void)
> >          |      ^~~~~~~~~~~~~~~~~~~~~~~~~
> 
> As the comment states, this is needed only because the linker script
> vmlinux.lds.h references them, and it will not build without it.
> 
> If someone really cares, they could simply add a header to quiet these
> warnings, but seriously, these functions are just stubs to allow the sh
> boot portion use the vmlinux.lds.h linker script. These stubs are only for
> satisfying linker references and are not used. I'm not going to be the one
> to bother "fixing" it.

Thanks a lot for the details. We've configured the bot to ignore this on
the reported commit.

Best Regards,
Yujie

> 
> -- Steve
> 
> 
> >    arch/sh/boot/compressed/misc.c:128:6: warning: no previous prototype for 'decompress_kernel' [-Wmissing-prototypes]
> >      128 | void decompress_kernel(void)
> >          |      ^~~~~~~~~~~~~~~~~
> > 
> > 
> > vim +/arch_ftrace_ops_list_func +118 arch/sh/boot/compressed/misc.c
> > 
> >    113	
> >    114	/* Needed because vmlinux.lds.h references this */
> >    115	void ftrace_stub(void)
> >    116	{
> >    117	}
> >  > 118	void arch_ftrace_ops_list_func(void)  
> >    119	{
> >    120	}
> >    121	
> > 
> 
>