[kees:kspp/array-bounds/next-20210816/v1 9/10] include/linux/fortify-string.h:20:33: warning: '__builtin_memcpy' offset [0, 511] is out of the bounds [0, 0]

From: kernel test robot
Date: Wed Aug 18 2021 - 07:09:40 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git kspp/array-bounds/next-20210816/v1
head: b07d5e8190ca172b1ffddd1412b921296000b379
commit: ecc23a9ee765008e439113eea38fb1cbbd3d7c83 [9/10] Makefile: Enable -Warray-bounds
config: s390-randconfig-r001-20210816 (attached as .config)
compiler: s390-linux-gcc (GCC) 11.2.0
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/kees/linux.git/commit/?id=ecc23a9ee765008e439113eea38fb1cbbd3d7c83
git remote add kees https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git
git fetch --no-tags kees kspp/array-bounds/next-20210816/v1
git checkout ecc23a9ee765008e439113eea38fb1cbbd3d7c83
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=s390

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

In file included from include/linux/string.h:262,
from include/linux/bitmap.h:10,
from include/linux/cpumask.h:12,
from include/linux/smp.h:13,
from include/linux/lockdep.h:14,
from include/linux/rcupdate.h:29,
from include/linux/rculist.h:11,
from include/linux/pid.h:5,
from include/linux/sched.h:14,
from include/linux/ratelimit.h:6,
from include/linux/dev_printk.h:16,
from include/linux/device.h:15,
from arch/s390/kernel/machine_kexec.c:10:
In function 'memcpy',
inlined from '__do_machine_kdump' at arch/s390/kernel/machine_kexec.c:58:2:
>> include/linux/fortify-string.h:20:33: warning: '__builtin_memcpy' offset [0, 511] is out of the bounds [0, 0] [-Warray-bounds]
20 | #define __underlying_memcpy __builtin_memcpy
| ^
include/linux/fortify-string.h:191:16: note: in expansion of macro '__underlying_memcpy'
191 | return __underlying_memcpy(p, q, size);
| ^~~~~~~~~~~~~~~~~~~


vim +/__builtin_memcpy +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@xxxxxxxxxxxxxxxxxxx>
:::::: CC: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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