[kbuild-all] [djwong-xfs:xfs-5.12-merge 2/6] include/linux/string.h:291:30: error: '__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/djwong/xfs-linux.git xfs-5.12-merge head: 45d6842f11a30d152b849ca819a91331b5f94f56 commit: ff344abb1b45079f292cf90e039ce0c5f7ee9988 [2/6] xfs: don't crash with assfail config: i386-randconfig-a001-20210118 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git/comm... git remote add djwong-xfs https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git git fetch --no-tags djwong-xfs xfs-5.12-merge git checkout ff344abb1b45079f292cf90e039ce0c5f7ee9988 # save the attached .config to linux build tree make W=1 ARCH=i386 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 >>): In file included 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: 291 | #define __underlying_strncpy __builtin_strncpy | ^ include/linux/string.h:301:9: note: in expansion of macro '__underlying_strncpy' 301 | return __underlying_strncpy(p, q, size); | ^~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +/__builtin_strncpy +291 include/linux/string.h 47227d27e2fcb01a Daniel Axtens 2020-06-03 269 0fea6e9af889f1a4 Andrey Konovalov 2020-12-22 270 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 47227d27e2fcb01a Daniel Axtens 2020-06-03 271 extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr); 47227d27e2fcb01a Daniel Axtens 2020-06-03 272 extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp); 47227d27e2fcb01a Daniel Axtens 2020-06-03 273 extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy); 47227d27e2fcb01a Daniel Axtens 2020-06-03 274 extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove); 47227d27e2fcb01a Daniel Axtens 2020-06-03 275 extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset); 47227d27e2fcb01a Daniel Axtens 2020-06-03 276 extern char *__underlying_strcat(char *p, const char *q) __RENAME(strcat); 47227d27e2fcb01a Daniel Axtens 2020-06-03 277 extern char *__underlying_strcpy(char *p, const char *q) __RENAME(strcpy); 47227d27e2fcb01a Daniel Axtens 2020-06-03 278 extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen); 47227d27e2fcb01a Daniel Axtens 2020-06-03 279 extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat); 47227d27e2fcb01a Daniel Axtens 2020-06-03 280 extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy); 47227d27e2fcb01a Daniel Axtens 2020-06-03 281 #else 47227d27e2fcb01a Daniel Axtens 2020-06-03 282 #define __underlying_memchr __builtin_memchr 47227d27e2fcb01a Daniel Axtens 2020-06-03 283 #define __underlying_memcmp __builtin_memcmp 47227d27e2fcb01a Daniel Axtens 2020-06-03 284 #define __underlying_memcpy __builtin_memcpy 47227d27e2fcb01a Daniel Axtens 2020-06-03 285 #define __underlying_memmove __builtin_memmove 47227d27e2fcb01a Daniel Axtens 2020-06-03 286 #define __underlying_memset __builtin_memset 47227d27e2fcb01a Daniel Axtens 2020-06-03 287 #define __underlying_strcat __builtin_strcat 47227d27e2fcb01a Daniel Axtens 2020-06-03 288 #define __underlying_strcpy __builtin_strcpy 47227d27e2fcb01a Daniel Axtens 2020-06-03 289 #define __underlying_strlen __builtin_strlen 47227d27e2fcb01a Daniel Axtens 2020-06-03 290 #define __underlying_strncat __builtin_strncat 47227d27e2fcb01a Daniel Axtens 2020-06-03 @291 #define __underlying_strncpy __builtin_strncpy 47227d27e2fcb01a Daniel Axtens 2020-06-03 292 #endif 47227d27e2fcb01a Daniel Axtens 2020-06-03 293 :::::: The code at line 291 was first introduced by commit :::::: 47227d27e2fcb01a9e8f5958d8997cf47a820afc string.h: fix incompatibility between FORTIFY_SOURCE and KASAN :::::: TO: Daniel Axtens <dja(a)axtens.net&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