[PATCH 1/3] powerpc/ftrace: Reserve instructions from function entry for ftrace

[kernel test robot]

Hi "Naveen,

I love your patch! Perhaps something to improve:

[auto build test WARNING on 1b43a74f255c5c00db25a5fedfd75ca0dc029022]

url:    https://github.com/0day-ci/linux/commits/Naveen-N-Rao/powerpc-ftrace-Reserve-instructions-from-function-entry-for-ftrace/20220217-200314
base:   1b43a74f255c5c00db25a5fedfd75ca0dc029022
config: powerpc-allyesconfig (https://download.01.org/0day-ci/archive/20220218/202202180014.IWuzQ9al-lkp@intel.com/config)
compiler: powerpc-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/6a1891335e377e5def312e7c182aef676f04c926
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Naveen-N-Rao/powerpc-ftrace-Reserve-instructions-from-function-entry-for-ftrace/20220217-200314
        git checkout 6a1891335e377e5def312e7c182aef676f04c926
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash arch/powerpc/kernel/trace/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp at intel.com>

All warnings (new ones prefixed by >>):

>> arch/powerpc/kernel/trace/ftrace.c:504:5: warning: no previous prototype for 'ftrace_location_get_offset' [-Wmissing-prototypes]
     504 | int ftrace_location_get_offset(const struct dyn_ftrace *rec)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/ftrace_location_get_offset +504 arch/powerpc/kernel/trace/ftrace.c

   502	
   503	#if defined(CONFIG_MPROFILE_KERNEL) || defined(CONFIG_PPC32)
 > 504	int ftrace_location_get_offset(const struct dyn_ftrace *rec)
   505	{
   506		if (IS_ENABLED(CONFIG_MPROFILE_KERNEL))
   507			/*
   508			 * On ppc64le with -mprofile-kernel, function entry can have:
   509			 *   addis r2, r12, M
   510			 *   addi  r2, r2, N
   511			 *   mflr  r0
   512			 *   bl    _mcount
   513			 *
   514			 * The first two instructions are for TOC setup and represent the global entry
   515			 * point for cross-module calls, and may be missing if the function is never called
   516			 * from other modules.
   517			 */
   518			return ((unsigned long)rec->arch.mod & 0x1) ? FUNC_MCOUNT_OFFSET_PPC64_GEP :
   519								      FUNC_MCOUNT_OFFSET_PPC64_LEP;
   520		else
   521			/*
   522			 * On ppc32, function entry always has:
   523			 *   mflr r0
   524			 *   stw  r0, 4(r1)
   525			 *   bl   _mcount
   526			 */
   527			return FUNC_MCOUNT_OFFSET_PPC32;
   528	}
   529	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org