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.gi... 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(a)intel.com&gt; 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 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(a)canb.auug.org.au&gt; :::::: CC: Stephen Rothwell <sfr(a)canb.auug.org.au&gt; 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