tree: https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git arm-kill-set_fs-5 head: 1086c1cb895540fdf215aecf3ed4a96843d6633e commit: 175180f99fef4558bae0c2fb337150706c4297ea [6/40] ARM: traps: use get_kernel_nofault instead of set_fs() config: arm-randconfig-r022-20200917 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 0ff28fa6a75617d61b1aeea77463d6a1684c3c89) 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 arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi git checkout 175180f99fef4558bae0c2fb337150706c4297ea # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): arch/arm/kernel/traps.c:82:6: warning: no previous prototype for function 'dump_backtrace_stm' [-Wmissing-prototypes] void dump_backtrace_stm(u32 *stack, u32 instruction, const char *loglvl) ^ arch/arm/kernel/traps.c:82:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void dump_backtrace_stm(u32 *stack, u32 instruction, const char *loglvl) ^ static if (get_kernel_nofault(val, (u32 *)p)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/uaccess.h:366:21: note: expanded from macro 'get_kernel_nofault' const typeof(val) *__gk_ptr = (ptr); \ ^ ~~~~~ arch/arm/kernel/traps.c:430:17: warning: no previous prototype for function 'do_undefinstr' [-Wmissing-prototypes] asmlinkage void do_undefinstr(struct pt_regs *regs) ^ arch/arm/kernel/traps.c:430:12: note: declare 'static' if the function is not intended to be used outside of this translation unit asmlinkage void do_undefinstr(struct pt_regs *regs) ^ static arch/arm/kernel/traps.c:495:39: warning: no previous prototype for function 'handle_fiq_as_nmi' [-Wmissing-prototypes] asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs) ^ arch/arm/kernel/traps.c:495:12: note: declare 'static' if the function is not intended to be used outside of this translation unit asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs) ^ static arch/arm/kernel/traps.c:514:17: warning: no previous prototype for function 'bad_mode' [-Wmissing-prototypes] asmlinkage void bad_mode(struct pt_regs *regs, int reason) ^ arch/arm/kernel/traps.c:514:12: note: declare 'static' if the function is not intended to be used outside of this translation unit asmlinkage void bad_mode(struct pt_regs *regs, int reason) ^ static arch/arm/kernel/traps.c:587:16: warning: no previous prototype for function 'arm_syscall' [-Wmissing-prototypes] asmlinkage int arm_syscall(int no, struct pt_regs *regs) ^ arch/arm/kernel/traps.c:587:12: note: declare 'static' if the function is not intended to be used outside of this translation unit asmlinkage int arm_syscall(int no, struct pt_regs *regs) ^ static arch/arm/kernel/traps.c:713:1: warning: no previous prototype for function 'baddataabort' [-Wmissing-prototypes] baddataabort(int code, unsigned long instr, struct pt_regs *regs) ^ arch/arm/kernel/traps.c:712:12: note: declare 'static' if the function is not intended to be used outside of this translation unit asmlinkage void ^ static arch/arm/kernel/traps.c:738:6: warning: no previous prototype for function '__pte_error' [-Wmissing-prototypes] void __pte_error(const char *file, int line, pte_t pte) ^ arch/arm/kernel/traps.c:738:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __pte_error(const char *file, int line, pte_t pte) ^ static arch/arm/kernel/traps.c:743:6: warning: no previous prototype for function '__pmd_error' [-Wmissing-prototypes] void __pmd_error(const char *file, int line, pmd_t pmd) ^ arch/arm/kernel/traps.c:743:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __pmd_error(const char *file, int line, pmd_t pmd) ^ static arch/arm/kernel/traps.c:748:6: warning: no previous prototype for function '__pgd_error' [-Wmissing-prototypes] void __pgd_error(const char *file, int line, pgd_t pgd) ^ arch/arm/kernel/traps.c:748:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __pgd_error(const char *file, int line, pgd_t pgd) ^ static arch/arm/kernel/traps.c:753:17: warning: no previous prototype for function '__div0' [-Wmissing-prototypes] asmlinkage void __div0(void) ^ arch/arm/kernel/traps.c:753:12: note: declare 'static' if the function is not intended to be used outside of this translation unit asmlinkage void __div0(void) ^ static arch/arm/kernel/traps.c:768:13: warning: no previous prototype for function 'trap_init' [-Wmissing-prototypes] void __init trap_init(void) ^ arch/arm/kernel/traps.c:768:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void __init trap_init(void) ^ static 11 warnings and 1 error generated. # https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/commi... git remote add arnd-playground https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git git fetch --no-tags arnd-playground arm-kill-set_fs-5 git checkout 175180f99fef4558bae0c2fb337150706c4297ea vim +139 arch/arm/kernel/traps.c 117 118 /* 119 * Dump out the contents of some memory nicely... 120 */ 121 static void dump_mem(const char *lvl, const char *str, unsigned long bottom, 122 unsigned long top) 123 { 124 unsigned long first; 125 int i; 126 127 printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top); 128 129 for (first = bottom & ~31; first < top; first += 32) { 130 unsigned long p; 131 char str[sizeof(" 12345678") * 8 + 1]; 132 133 memset(str, ' ', sizeof(str)); 134 str[sizeof(str) - 1] = '\0'; 135 136 for (p = first, i = 0; i < 8 && p < top; i++, p += 4) { 137 if (p >= bottom && p < top) { 138 unsigned long val; 140 sprintf(str + i * 9, " %08lx", val); 141 else 142 sprintf(str + i * 9, " ????????"); 143 } 144 } 145 printk("%s%04lx:%s\n", lvl, first & 0xffff, str); 146 } 147 } 148 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org