[kbuild-all] [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]

Wednesday, 18 August 2021

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...
        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(a)intel.com&gt;

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(a)privacyrequired.com&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

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[kbuild-all] [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]