Hi Christophe,

First bad commit (maybe != root cause):

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   1140ab592e2ebf8153d2b322604031a8868ce7a5
commit: eacf4c0202654adfa94bbb17b5c5c77c0be14af8 powerpc: Enable OPTPROBES on PPC32
date:   3 weeks ago
config: powerpc-randconfig-r033-20210511 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project a0fed635fe1701470062495a6ffee1c608f3f1bc)
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
        # install powerpc cross compiling tool for clang build
        # apt-get install binutils-powerpc-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eacf4c0202654adfa94bbb17b5c5c77c0be14af8
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout eacf4c0202654adfa94bbb17b5c5c77c0be14af8
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=powerpc 

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

All errors (new ones prefixed by >>):

>> arch/powerpc/kernel/optprobes.c:34:1: error: unused function 'is_kprobe_ppc_optinsn_slot' [-Werror,-Wunused-function]
   DEFINE_INSN_CACHE_OPS(ppc_optinsn);
   ^
   include/linux/kprobes.h:306:20: note: expanded from macro 'DEFINE_INSN_CACHE_OPS'
   static inline bool is_kprobe_##__name##_slot(unsigned long addr)        \
                      ^
   <scratch space>:16:1: note: expanded from here
   is_kprobe_ppc_optinsn_slot
   ^
   1 error generated.


vim +/is_kprobe_ppc_optinsn_slot +34 arch/powerpc/kernel/optprobes.c

51c9c084399352 Anju T 2017-02-08  20  
51c9c084399352 Anju T 2017-02-08  21  #define TMPL_CALL_HDLR_IDX	\
51c9c084399352 Anju T 2017-02-08  22  	(optprobe_template_call_handler - optprobe_template_entry)
51c9c084399352 Anju T 2017-02-08  23  #define TMPL_EMULATE_IDX	\
51c9c084399352 Anju T 2017-02-08  24  	(optprobe_template_call_emulate - optprobe_template_entry)
51c9c084399352 Anju T 2017-02-08  25  #define TMPL_RET_IDX		\
51c9c084399352 Anju T 2017-02-08  26  	(optprobe_template_ret - optprobe_template_entry)
51c9c084399352 Anju T 2017-02-08  27  #define TMPL_OP_IDX		\
51c9c084399352 Anju T 2017-02-08  28  	(optprobe_template_op_address - optprobe_template_entry)
51c9c084399352 Anju T 2017-02-08  29  #define TMPL_INSN_IDX		\
51c9c084399352 Anju T 2017-02-08  30  	(optprobe_template_insn - optprobe_template_entry)
51c9c084399352 Anju T 2017-02-08  31  #define TMPL_END_IDX		\
51c9c084399352 Anju T 2017-02-08  32  	(optprobe_template_end - optprobe_template_entry)
51c9c084399352 Anju T 2017-02-08  33  
51c9c084399352 Anju T 2017-02-08 @34  DEFINE_INSN_CACHE_OPS(ppc_optinsn);
51c9c084399352 Anju T 2017-02-08  35  

:::::: The code at line 34 was first introduced by commit
:::::: 51c9c0843993528bffc920c54c2121d9e6f8b090 powerpc/kprobes: Implement Optprobes

:::::: TO: Anju T <anju@linux.vnet.ibm.com>
:::::: CC: Michael Ellerman <mpe@ellerman.id.au>

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