[gustavoars-linux:for-next/Warray-bounds 3/3] include/linux/fortify-string.h:20:29: warning: '__builtin_memcpy' offset [17, 24] from the object at 'alloc' is out of the bounds of referenced subobject 'key' with type 'struct bkey' at offset 0

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

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tree:   https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git for-next/Warray-bounds
head:   12f0a8412db185d4fe79208083b373a0c02b6ee9
commit: 12f0a8412db185d4fe79208083b373a0c02b6ee9 [3/3] Makefile: Enable -Warray-bounds
config: powerpc-allmodconfig (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 9.3.0
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/gustavoars/linux.git/commit/?id=12f0a8412db185d4fe79208083b373a0c02b6ee9
        git remote add gustavoars-linux https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git
        git fetch --no-tags gustavoars-linux for-next/Warray-bounds
        git checkout 12f0a8412db185d4fe79208083b373a0c02b6ee9
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc 

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

All warnings (new ones prefixed by >>):

   In file included from include/linux/string.h:269,
                    from arch/powerpc/include/asm/paca.h:15,
                    from arch/powerpc/include/asm/current.h:13,
                    from include/linux/thread_info.h:22,
                    from include/asm-generic/preempt.h:5,
                    from ./arch/powerpc/include/generated/asm/preempt.h:1,
                    from include/linux/preempt.h:78,
                    from include/linux/spinlock.h:51,
                    from include/linux/wait.h:9,
                    from include/linux/wait_bit.h:8,
                    from include/linux/fs.h:6,
                    from include/linux/highmem.h:5,
                    from include/linux/bio.h:8,
                    from drivers/md/bcache/bcache.h:182,
                    from drivers/md/bcache/alloc.c:64:
   In function 'memcpy',
       inlined from 'pick_data_bucket' at drivers/md/bcache/alloc.c:586:3,
       inlined from 'bch_alloc_sectors' at drivers/md/bcache/alloc.c:627:15:
>> include/linux/fortify-string.h:20:29: warning: '__builtin_memcpy' offset [17, 24] from the object at 'alloc' is out of the bounds of referenced subobject 'key' with type 'struct bkey' at offset 0 [-Warray-bounds]
      20 | #define __underlying_memcpy __builtin_memcpy
         |                             ^
   include/linux/fortify-string.h:191:9: note: in expansion of macro '__underlying_memcpy'
     191 |  return __underlying_memcpy(p, q, size);
         |         ^~~~~~~~~~~~~~~~~~~


vim +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@privacyrequired.com>
:::::: CC: Linus Torvalds <torvalds@linux-foundation.org>

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

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