[kbuild-all] [linux-next:master 2770/2798] include/linux/fortify-string.h:27:30: warning: '__builtin_strncpy' output may be truncated copying between 5 and 9 bytes from a string of length 9

tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: aa515cdce7a151dcc14b7600d33f1414c6fa32c9 commit: 97a31c94fce5a46cd09fd6a987418e6acd2b8e24 [2770/2798] string.h: move fortified functions definitions in a dedicated header. config: mips-randconfig-r011-20210113 (attached as .config) compiler: mipsel-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/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout 97a31c94fce5a46cd09fd6a987418e6acd2b8e24 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips 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 include/linux/uuid.h:12, from fs/xfs/xfs_linux.h:10, from fs/xfs/xfs.h:22, from fs/xfs/xfs_xattr.c:7: In function 'strncpy', inlined from '__xfs_xattr_put_listent' at fs/xfs/xfs_xattr.c:118:2, inlined from 'xfs_xattr_put_listent' at fs/xfs/xfs_xattr.c:180:2: 27 | #define __underlying_strncpy __builtin_strncpy | ^ include/linux/fortify-string.h:38:9: note: in expansion of macro '__underlying_strncpy' 38 | return __underlying_strncpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~~ -- In file included from include/linux/string.h:269, from include/linux/bitmap.h:9, from include/linux/cpumask.h:12, from include/linux/smp.h:13, from arch/mips/include/asm/cpu-type.h:12, from arch/mips/include/asm/timex.h:19, from include/linux/timex.h:65, from include/linux/time32.h:13, from include/linux/time.h:60, from include/linux/compat.h:10, from drivers/hid/uhid.c:11: In function 'strncpy', inlined from 'uhid_dev_create2' at drivers/hid/uhid.c:499:2: 27 | #define __underlying_strncpy __builtin_strncpy | ^ include/linux/fortify-string.h:38:9: note: in expansion of macro '__underlying_strncpy' 38 | return __underlying_strncpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~~ In function 'strncpy', inlined from 'uhid_dev_create2' at drivers/hid/uhid.c:501:2: include/linux/fortify-string.h:27:30: warning: '__builtin_strncpy' output may be truncated copying 63 bytes from a string of length 63 [-Wstringop-truncation] 27 | #define __underlying_strncpy __builtin_strncpy | ^ include/linux/fortify-string.h:38:9: note: in expansion of macro '__underlying_strncpy' 38 | return __underlying_strncpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~~ In function 'strncpy', inlined from 'uhid_dev_create2' at drivers/hid/uhid.c:503:2: include/linux/fortify-string.h:27:30: warning: '__builtin_strncpy' output may be truncated copying 63 bytes from a string of length 63 [-Wstringop-truncation] 27 | #define __underlying_strncpy __builtin_strncpy | ^ include/linux/fortify-string.h:38:9: note: in expansion of macro '__underlying_strncpy' 38 | return __underlying_strncpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~~ -- In file included from include/linux/string.h:269, from include/linux/bitmap.h:9, from include/linux/cpumask.h:12, from include/linux/smp.h:13, from arch/mips/include/asm/cpu-type.h:12, from arch/mips/include/asm/timex.h:19, from include/linux/timex.h:65, from include/linux/time32.h:13, from include/linux/time.h:60, from include/linux/stat.h:19, from include/linux/module.h:13, from drivers/video/fbdev/uvesafb.c:13: In function 'strncpy', inlined from 'uvesafb_vbe_getinfo' at drivers/video/fbdev/uvesafb.c:426:2: include/linux/fortify-string.h:27:30: warning: '__builtin_strncpy' output truncated before terminating nul copying 4 bytes from a string of the same length [-Wstringop-truncation] 27 | #define __underlying_strncpy __builtin_strncpy | ^ include/linux/fortify-string.h:38:9: note: in expansion of macro '__underlying_strncpy' 38 | return __underlying_strncpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~~ In function 'strncpy', inlined from 'v86d_store' at drivers/video/fbdev/uvesafb.c:1874:2: 27 | #define __underlying_strncpy __builtin_strncpy | ^ include/linux/fortify-string.h:38:9: note: in expansion of macro '__underlying_strncpy' 38 | return __underlying_strncpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~~ vim +/__builtin_strncpy +27 include/linux/fortify-string.h 4 5 6 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 7 extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr); 8 extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp); 9 extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy); 10 extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove); 11 extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset); 12 extern char *__underlying_strcat(char *p, const char *q) __RENAME(strcat); 13 extern char *__underlying_strcpy(char *p, const char *q) __RENAME(strcpy); 14 extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen); 15 extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat); 16 extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy); 17 #else 18 #define __underlying_memchr __builtin_memchr 19 #define __underlying_memcmp __builtin_memcmp 20 #define __underlying_memcpy __builtin_memcpy 21 #define __underlying_memmove __builtin_memmove 22 #define __underlying_memset __builtin_memset 23 #define __underlying_strcat __builtin_strcat 24 #define __underlying_strcpy __builtin_strcpy 25 #define __underlying_strlen __builtin_strlen 26 #define __underlying_strncat __builtin_strncat 28 #endif 29 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org