include/linux/fortify-string.h:52:29: warning: '__builtin_strcpy' source argument is the same as destination

kernel test robot
2023-11-30T04:03:12Z

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 3b47bc037bd44f142ac09848e8d3ecccc726be99
commit: ba38961a069b0d8d03b53218a6c29d737577d448 um: Enable FORTIFY_SOURCE
date: 1 year, 3 months ago
config: um-randconfig-r034-20230830 (https://download.01.org/0day-ci/archive/20231130/202311301039.7i51bZCz-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231130/202311301039.7i51bZCz-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311301039.7i51bZCz-lkp@intel.com/

All warnings (new ones prefixed by >>):

kernel/kallsyms.c:570:12: warning: no previous prototype for 'arch_get_kallsym' [-Wmissing-prototypes]
570 | int __weak arch_get_kallsym(unsigned int symnum, unsigned long *value,
| ^~~~~~~~~~~~~~~~
In file included from include/linux/string.h:253,
from include/linux/bitmap.h:11,
from include/linux/cpumask.h:12,
from include/linux/mm_types_task.h:14,
from include/linux/mm_types.h:5,
from include/linux/buildid.h:5,
from include/linux/kallsyms.h:10,
from kernel/kallsyms.c:15:
kernel/kallsyms.c: In function '__sprint_symbol.isra.0':
>> include/linux/fortify-string.h:52:29: warning: '__builtin_strcpy' source argument is the same as destination [-Wrestrict]
52 | #define __underlying_strcpy __builtin_strcpy
| ^
include/linux/fortify-string.h:567:10: note: in expansion of macro '__underlying_strcpy'
567 | return __underlying_strcpy(p, q);
| ^~~~~~~~~~~~~~~~~~~

vim +/__builtin_strcpy +52 include/linux/fortify-string.h

3009f891bb9f32 Kees Cook 2021-08-02 33
a28a6e860c6cf2 Francis Laniel 2021-02-25 34 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
a28a6e860c6cf2 Francis Laniel 2021-02-25 35 extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr);
a28a6e860c6cf2 Francis Laniel 2021-02-25 36 extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp);
a28a6e860c6cf2 Francis Laniel 2021-02-25 37 extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy);
a28a6e860c6cf2 Francis Laniel 2021-02-25 38 extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove);
a28a6e860c6cf2 Francis Laniel 2021-02-25 39 extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset);
a28a6e860c6cf2 Francis Laniel 2021-02-25 40 extern char *__underlying_strcat(char *p, const char *q) __RENAME(strcat);
a28a6e860c6cf2 Francis Laniel 2021-02-25 41 extern char *__underlying_strcpy(char *p, const char *q) __RENAME(strcpy);
a28a6e860c6cf2 Francis Laniel 2021-02-25 42 extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen);
a28a6e860c6cf2 Francis Laniel 2021-02-25 43 extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat);
a28a6e860c6cf2 Francis Laniel 2021-02-25 44 extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy);
a28a6e860c6cf2 Francis Laniel 2021-02-25 45 #else
a28a6e860c6cf2 Francis Laniel 2021-02-25 46 #define __underlying_memchr __builtin_memchr
a28a6e860c6cf2 Francis Laniel 2021-02-25 47 #define __underlying_memcmp __builtin_memcmp
a28a6e860c6cf2 Francis Laniel 2021-02-25 48 #define __underlying_memcpy __builtin_memcpy
a28a6e860c6cf2 Francis Laniel 2021-02-25 49 #define __underlying_memmove __builtin_memmove
a28a6e860c6cf2 Francis Laniel 2021-02-25 50 #define __underlying_memset __builtin_memset
a28a6e860c6cf2 Francis Laniel 2021-02-25 51 #define __underlying_strcat __builtin_strcat
a28a6e860c6cf2 Francis Laniel 2021-02-25 @52 #define __underlying_strcpy __builtin_strcpy
a28a6e860c6cf2 Francis Laniel 2021-02-25 53 #define __underlying_strlen __builtin_strlen
a28a6e860c6cf2 Francis Laniel 2021-02-25 54 #define __underlying_strncat __builtin_strncat
a28a6e860c6cf2 Francis Laniel 2021-02-25 55 #define __underlying_strncpy __builtin_strncpy
a28a6e860c6cf2 Francis Laniel 2021-02-25 56 #endif
a28a6e860c6cf2 Francis Laniel 2021-02-25 57

:::::: The code at line 52 was first introduced by commit
:::::: a28a6e860c6cf231cf3c5171c75c342adcd00406 string.h: move fortified functions definitions in a dedicated header.

:::::: TO: Francis Laniel <laniel_francis@privacyrequired.com>
:::::: CC: Linus Torvalds <torvalds@linux-foundation.org>

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