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

[kernel test robot <lkp@intel.com>]

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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