tree: https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git for-next/Warray-bounds head: 12f0a8412db185d4fe79208083b373a0c02b6ee9 commit: 12f0a8412db185d4fe79208083b373a0c02b6ee9 [3/3] Makefile: Enable -Warray-bounds config: powerpc-allmodconfig (attached as .config) compiler: powerpc64-linux-gcc (GCC) 9.3.0 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/gustavoars/linux.git/comm... git remote add gustavoars-linux https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git git fetch --no-tags gustavoars-linux for-next/Warray-bounds git checkout 12f0a8412db185d4fe79208083b373a0c02b6ee9 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 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; All warnings (new ones prefixed by >>): In file included from include/linux/string.h:269, from arch/powerpc/include/asm/paca.h:15, from arch/powerpc/include/asm/current.h:13, from include/linux/thread_info.h:22, from include/asm-generic/preempt.h:5, from ./arch/powerpc/include/generated/asm/preempt.h:1, from include/linux/preempt.h:78, from include/linux/spinlock.h:51, from include/linux/wait.h:9, from include/linux/wait_bit.h:8, from include/linux/fs.h:6, from include/linux/highmem.h:5, from include/linux/bio.h:8, from drivers/md/bcache/bcache.h:182, from drivers/md/bcache/alloc.c:64: In function 'memcpy', inlined from 'pick_data_bucket' at drivers/md/bcache/alloc.c:586:3, inlined from 'bch_alloc_sectors' at drivers/md/bcache/alloc.c:627:15: 20 | #define __underlying_memcpy __builtin_memcpy | ^ include/linux/fortify-string.h:191:9: note: in expansion of macro '__underlying_memcpy' 191 | return __underlying_memcpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~ vim +20 include/linux/fortify-string.h a28a6e860c6cf2 Francis Laniel 2021-02-25 4 a28a6e860c6cf2 Francis Laniel 2021-02-25 5 a28a6e860c6cf2 Francis Laniel 2021-02-25 6 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) a28a6e860c6cf2 Francis Laniel 2021-02-25 7 extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr); a28a6e860c6cf2 Francis Laniel 2021-02-25 8 extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp); a28a6e860c6cf2 Francis Laniel 2021-02-25 9 extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy); a28a6e860c6cf2 Francis Laniel 2021-02-25 10 extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove); a28a6e860c6cf2 Francis Laniel 2021-02-25 11 extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset); a28a6e860c6cf2 Francis Laniel 2021-02-25 12 extern char *__underlying_strcat(char *p, const char *q) __RENAME(strcat); a28a6e860c6cf2 Francis Laniel 2021-02-25 13 extern char *__underlying_strcpy(char *p, const char *q) __RENAME(strcpy); a28a6e860c6cf2 Francis Laniel 2021-02-25 14 extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen); a28a6e860c6cf2 Francis Laniel 2021-02-25 15 extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat); a28a6e860c6cf2 Francis Laniel 2021-02-25 16 extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy); a28a6e860c6cf2 Francis Laniel 2021-02-25 17 #else a28a6e860c6cf2 Francis Laniel 2021-02-25 18 #define __underlying_memchr __builtin_memchr a28a6e860c6cf2 Francis Laniel 2021-02-25 19 #define __underlying_memcmp __builtin_memcmp a28a6e860c6cf2 Francis Laniel 2021-02-25 @20 #define __underlying_memcpy __builtin_memcpy a28a6e860c6cf2 Francis Laniel 2021-02-25 21 #define __underlying_memmove __builtin_memmove a28a6e860c6cf2 Francis Laniel 2021-02-25 22 #define __underlying_memset __builtin_memset a28a6e860c6cf2 Francis Laniel 2021-02-25 23 #define __underlying_strcat __builtin_strcat a28a6e860c6cf2 Francis Laniel 2021-02-25 24 #define __underlying_strcpy __builtin_strcpy a28a6e860c6cf2 Francis Laniel 2021-02-25 25 #define __underlying_strlen __builtin_strlen a28a6e860c6cf2 Francis Laniel 2021-02-25 26 #define __underlying_strncat __builtin_strncat a28a6e860c6cf2 Francis Laniel 2021-02-25 27 #define __underlying_strncpy __builtin_strncpy a28a6e860c6cf2 Francis Laniel 2021-02-25 28 #endif a28a6e860c6cf2 Francis Laniel 2021-02-25 29 :::::: The code at line 20 was first introduced by commit :::::: a28a6e860c6cf231cf3c5171c75c342adcd00406 string.h: move fortified functions definitions in a dedicated header. :::::: TO: Francis Laniel <laniel_francis(a)privacyrequired.com&gt; :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org