Re: [PATCH] ftrace: Fix stack trace entry generated by ftrace_pid_func()

[Tatsuya S]

On Mon, May 27, 2024 at 08:17:19AM GMT, Masami Hiramatsu wrote:
> On Sun, 26 May 2024 22:51:53 +0800
> kernel test robot <lkp@xxxxxxxxx> wrote:
> 
> > Hi Tatsuya,
> > 
> > kernel test robot noticed the following build warnings:
> > 
> > [auto build test WARNING on linus/master]
> > [also build test WARNING on rostedt-trace/for-next v6.9 next-20240523]
> > [cannot apply to rostedt-trace/for-next-urgent]
> > [If your patch is applied to the wrong git tree, kindly drop us a note.
> > And when submitting patch, we suggest to use '--base' as documented in
> > https://git-scm.com/docs/git-format-patch#_base_tree_information]
> > 
> > url:    https://github.com/intel-lab-lkp/linux/commits/Tatsuya-S/ftrace-Fix-stack-trace-entry-generated-by-ftrace_pid_func/20240526-193149
> > base:   linus/master
> > patch link:    https://lore.kernel.org/r/20240526112658.46740-1-tatsuya.s2862%40gmail.com
> > patch subject: [PATCH] ftrace: Fix stack trace entry generated by ftrace_pid_func()
> > config: x86_64-buildonly-randconfig-002-20240526 (https://download.01.org/0day-ci/archive/20240526/202405262232.L4XH8q6O-lkp@xxxxxxxxx/config)
> > compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1)
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240526/202405262232.L4XH8q6O-lkp@xxxxxxxxx/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@xxxxxxxxx>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202405262232.L4XH8q6O-lkp@xxxxxxxxx/
> > 
> > All warnings (new ones prefixed by >>):
> > 
> > >> kernel/trace/ftrace.c:102:6: warning: no previous prototype for function 'ftrace_pids_enabled' [-Wmissing-prototypes]
> >      102 | bool ftrace_pids_enabled(struct ftrace_ops *ops)
> >          |      ^
> >    kernel/trace/ftrace.c:102:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
> >      102 | bool ftrace_pids_enabled(struct ftrace_ops *ops)
> >          | ^
> >          | static 
> >    1 warning generated.
> 
> This is because the prototype in linux/ftrace.h is placed in the 
> #ifdef CONFIG_DYNAMIC_FTRACE block. The prototype needs to be moved
> outside of the block.
> 
> Thank you,
> 
> > 
> > 
> > vim +/ftrace_pids_enabled +102 kernel/trace/ftrace.c
> > 
> >    101	
> >  > 102	bool ftrace_pids_enabled(struct ftrace_ops *ops)
> >    103	{
> >    104		struct trace_array *tr;
> >    105	
> >    106		if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
> >    107			return false;
> >    108	
> >    109		tr = ops->private;
> >    110	
> >    111		return tr->function_pids != NULL || tr->function_no_pids != NULL;
> >    112	}
> >    113	
> > 
> > -- 
> > 0-DAY CI Kernel Test Service
> > https://github.com/intel/lkp-tests/wiki
> 
> 
> -- 
> Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

I understand. Thank you.