Hi Mark,

FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git arm64/ftrace/minimal-regs
head:   4a6bd8952d26e3c2bcfd3fba2fbc10e0028fe7fa
commit: 4aceda490074390d6e93255e432d1a2027104997 [3/4] ftrace: pass fregs to arch_ftrace_set_direct_caller()
config: s390-allmodconfig
compiler: s390-linux-gcc (GCC) 12.1.0
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://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/commit/?id=4aceda490074390d6e93255e432d1a2027104997
        git remote add mark https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git
        git fetch --no-tags mark arm64/ftrace/minimal-regs
        git checkout 4aceda490074390d6e93255e432d1a2027104997
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 prepare

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

All error/warnings (new ones prefixed by >>):

   In file included from include/linux/ftrace.h:23,
                    from include/linux/kvm_host.h:32,
                    from arch/s390/kernel/asm-offsets.c:11:
   arch/s390/include/asm/ftrace.h: In function 'arch_ftrace_set_direct_caller':
>> arch/s390/include/asm/ftrace.h:85:32: error: implicit declaration of function 'ftrace_get_regs'; did you mean 'arch_ftrace_get_regs'? [-Werror=implicit-function-declaration]
      85 |         struct pt_regs *regs = ftrace_get_regs(fregs);
         |                                ^~~~~~~~~~~~~~~
         |                                arch_ftrace_get_regs
>> arch/s390/include/asm/ftrace.h:85:32: warning: initialization of 'struct pt_regs *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
   include/linux/ftrace.h: At top level:
>> include/linux/ftrace.h:121:40: error: conflicting types for 'ftrace_get_regs'; have 'struct pt_regs *(struct ftrace_regs *)'
     121 | static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
         |                                        ^~~~~~~~~~~~~~~
   arch/s390/include/asm/ftrace.h:85:32: note: previous implicit declaration of 'ftrace_get_regs' with type 'int()'
      85 |         struct pt_regs *regs = ftrace_get_regs(fregs);
         |                                ^~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors
   make[2]: *** [scripts/Makefile.build:117: arch/s390/kernel/asm-offsets.s] Error 1
   make[2]: Target '__build' not remade because of errors.
   make[1]: *** [Makefile:1205: prepare0] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:222: __sub-make] Error 2
   make: Target 'prepare' not remade because of errors.


vim +85 arch/s390/include/asm/ftrace.h

    75	
    76	/*
    77	 * When an ftrace registered caller is tracing a function that is
    78	 * also set by a register_ftrace_direct() call, it needs to be
    79	 * differentiated in the ftrace_caller trampoline. To do this,
    80	 * place the direct caller in the ORIG_GPR2 part of pt_regs. This
    81	 * tells the ftrace_caller that there's a direct caller.
    82	 */
    83	static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsigned long addr)
    84	{
  > 85		struct pt_regs *regs = ftrace_get_regs(fregs);
    86		regs->orig_gpr2 = addr;
    87	}
    88	

-- 
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https://01.org/lkp