tree:   https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.10.y
head:   81212a8abbf61ea75f691938b24d57cc1633e11c
commit: a024e88f8ab79a7b7e15337096d4f5f77edc6a49 [749/1625] powerpc/barrier: Avoid collision with clang's __lwsync macro
config: powerpc-randconfig-r035-20210813 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 62df4df41c939205b2dc0a2a3bfb75b8c1ed74fa)
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/stable/linux-stable-rc.git/commit/?id=a024e88f8ab79a7b7e15337096d4f5f77edc6a49
        git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
        git fetch --no-tags linux-stable-rc linux-5.10.y
        git checkout a024e88f8ab79a7b7e15337096d4f5f77edc6a49
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc 

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

Note: the linux-stable-rc/linux-5.10.y HEAD 81212a8abbf61ea75f691938b24d57cc1633e11c builds fine.
      It only hurts bisectibility.

All errors (new ones prefixed by >>):

   In file included from arch/powerpc/include/asm/hardirq.h:6:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:49:1: error: performing pointer arithmetic on a null pointer has undefined behavior [-Werror,-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsb, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:181:1: note: expanded from here
   __do_outsb
   ^
   arch/powerpc/include/asm/io.h:544:58: note: expanded from macro '__do_outsb'
   #define __do_outsb(p, b, n)     writesb((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from arch/powerpc/kernel/sys_ppc32.c:30:
   In file included from include/linux/syscalls.h:84:
   In file included from include/trace/syscall.h:7:
   In file included from include/linux/trace_events.h:9:
   In file included from include/linux/hardirq.h:10:
   In file included from arch/powerpc/include/asm/hardirq.h:6:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:51:1: error: performing pointer arithmetic on a null pointer has undefined behavior [-Werror,-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsw, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:183:1: note: expanded from here
   __do_outsw
   ^
   arch/powerpc/include/asm/io.h:545:58: note: expanded from macro '__do_outsw'
   #define __do_outsw(p, b, n)     writesw((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   In file included from arch/powerpc/kernel/sys_ppc32.c:30:
   In file included from include/linux/syscalls.h:84:
   In file included from include/trace/syscall.h:7:
   In file included from include/linux/trace_events.h:9:
   In file included from include/linux/hardirq.h:10:
   In file included from arch/powerpc/include/asm/hardirq.h:6:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:13:
   In file included from arch/powerpc/include/asm/io.h:604:
   arch/powerpc/include/asm/io-defs.h:53:1: error: performing pointer arithmetic on a null pointer has undefined behavior [-Werror,-Wnull-pointer-arithmetic]
   DEF_PCI_AC_NORET(outsl, (unsigned long p, const void *b, unsigned long c),
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   arch/powerpc/include/asm/io.h:601:3: note: expanded from macro 'DEF_PCI_AC_NORET'
                   __do_##name al;                                 \
                   ^~~~~~~~~~~~~~
   <scratch space>:185:1: note: expanded from here
   __do_outsl
   ^
   arch/powerpc/include/asm/io.h:546:58: note: expanded from macro '__do_outsl'
   #define __do_outsl(p, b, n)     writesl((PCI_IO_ADDR)_IO_BASE+(p),(b),(n))
                                           ~~~~~~~~~~~~~~~~~~~~~^
   arch/powerpc/kernel/sys_ppc32.c:51:15: error: no previous prototype for function 'compat_sys_mmap2' [-Werror,-Wmissing-prototypes]
   unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
                 ^
   arch/powerpc/kernel/sys_ppc32.c:51:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
   ^
   static 
   arch/powerpc/kernel/sys_ppc32.c:64:16: error: no previous prototype for function 'compat_sys_pread64' [-Werror,-Wmissing-prototypes]
   compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
                  ^
   arch/powerpc/kernel/sys_ppc32.c:64:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   compat_ssize_t compat_sys_pread64(unsigned int fd, char __user *ubuf, compat_size_t count,
   ^
   static 
   arch/powerpc/kernel/sys_ppc32.c:70:16: error: no previous prototype for function 'compat_sys_pwrite64' [-Werror,-Wmissing-prototypes]
   compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf, compat_size_t count,
                  ^
   arch/powerpc/kernel/sys_ppc32.c:70:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   compat_ssize_t compat_sys_pwrite64(unsigned int fd, const char __user *ubuf, compat_size_t count,
   ^
   static 
   arch/powerpc/kernel/sys_ppc32.c:76:16: error: no previous prototype for function 'compat_sys_readahead' [-Werror,-Wmissing-prototypes]
   compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offhi, u32 offlo, u32 count)
                  ^
   arch/powerpc/kernel/sys_ppc32.c:76:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   compat_ssize_t compat_sys_readahead(int fd, u32 r4, u32 offhi, u32 offlo, u32 count)
   ^
   static 
   arch/powerpc/kernel/sys_ppc32.c:81:16: error: no previous prototype for function 'compat_sys_truncate64' [-Werror,-Wmissing-prototypes]
   asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
                  ^
   arch/powerpc/kernel/sys_ppc32.c:81:12: note: declare 'static' if the function is not intended to be used outside of this translation unit
   asmlinkage int compat_sys_truncate64(const char __user * path, u32 reg4,
              ^
              static 
   arch/powerpc/kernel/sys_ppc32.c:87:17: error: no previous prototype for function 'compat_sys_fallocate' [-Werror,-Wmissing-prototypes]
   asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
                   ^
   arch/powerpc/kernel/sys_ppc32.c:87:12: note: declare 'static' if the function is not intended to be used outside of this translation unit
   asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
              ^
              static 
>> arch/powerpc/kernel/sys_ppc32.c:94:16: error: no previous prototype for function 'compat_sys_ftruncate64' [-Werror,-Wmissing-prototypes]
   asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long high,
                  ^
   arch/powerpc/kernel/sys_ppc32.c:94:12: note: declare 'static' if the function is not intended to be used outside of this translation unit
   asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long high,
              ^
              static 
   fatal error: too many errors emitted, stopping now [-ferror-limit=]
   20 errors generated.


vim +/compat_sys_ftruncate64 +94 arch/powerpc/kernel/sys_ppc32.c

^1da177e4c3f41 arch/ppc64/kernel/sys_ppc32.c   Linus Torvalds    2005-04-16  86  
97ac73506c0ba9 arch/powerpc/kernel/sys_ppc32.c Amit Arora        2007-07-17 @87  asmlinkage long compat_sys_fallocate(int fd, int mode, u32 offhi, u32 offlo,
97ac73506c0ba9 arch/powerpc/kernel/sys_ppc32.c Amit Arora        2007-07-17  88  				     u32 lenhi, u32 lenlo)
97ac73506c0ba9 arch/powerpc/kernel/sys_ppc32.c Amit Arora        2007-07-17  89  {
edf292c76b884a arch/powerpc/kernel/sys_ppc32.c Dominik Brodowski 2018-03-19  90  	return ksys_fallocate(fd, mode, ((loff_t)offhi << 32) | offlo,
97ac73506c0ba9 arch/powerpc/kernel/sys_ppc32.c Amit Arora        2007-07-17  91  			     ((loff_t)lenhi << 32) | lenlo);
97ac73506c0ba9 arch/powerpc/kernel/sys_ppc32.c Amit Arora        2007-07-17  92  }
97ac73506c0ba9 arch/powerpc/kernel/sys_ppc32.c Amit Arora        2007-07-17  93  
b09a4913b15d25 arch/powerpc/kernel/sys_ppc32.c Stephen Rothwell  2005-10-18 @94  asmlinkage int compat_sys_ftruncate64(unsigned int fd, u32 reg4, unsigned long high,
^1da177e4c3f41 arch/ppc64/kernel/sys_ppc32.c   Linus Torvalds    2005-04-16  95  				 unsigned long low)
^1da177e4c3f41 arch/ppc64/kernel/sys_ppc32.c   Linus Torvalds    2005-04-16  96  {
411d9475cf901b arch/powerpc/kernel/sys_ppc32.c Dominik Brodowski 2018-03-11  97  	return ksys_ftruncate(fd, (high << 32) | low);
^1da177e4c3f41 arch/ppc64/kernel/sys_ppc32.c   Linus Torvalds    2005-04-16  98  }
^1da177e4c3f41 arch/ppc64/kernel/sys_ppc32.c   Linus Torvalds    2005-04-16  99  

:::::: The code at line 94 was first introduced by commit
:::::: b09a4913b15d2544f8918f05b9937cb4e99a2319 powerpc: change sys32_ to compat_sys_

:::::: TO: Stephen Rothwell <sfr@canb.auug.org.au>
:::::: CC: Stephen Rothwell <sfr@canb.auug.org.au>

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