[gustavoars:testing/fam01-next20230530 9/9] include/linux/fortify-string.h:57:33: warning: writing 16 bytes into a region of size 0

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git testing/fam01-next20230530
head:   a2e8533878017f1874b21d78b6bf08a6c4095365
commit: a2e8533878017f1874b21d78b6bf08a6c4095365 [9/9] Makefile: Globally enable -Wstringop-overflow
config: arm64-allyesconfig (https://download.01.org/0day-ci/archive/20230531/202305310834.1iGa1DB5-lkp@xxxxxxxxx/config)
compiler: aarch64-linux-gcc (GCC) 12.3.0
reproduce (this is a W=1 build):
        mkdir -p ~/bin
        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=a2e8533878017f1874b21d78b6bf08a6c4095365
        git remote add gustavoars https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git
        git fetch --no-tags gustavoars testing/fam01-next20230530
        git checkout a2e8533878017f1874b21d78b6bf08a6c4095365
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=arm64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash fs/omfs/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202305310834.1iGa1DB5-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

   In file included from include/linux/string.h:254,
                    from include/linux/bitmap.h:11,
                    from include/linux/cpumask.h:12,
                    from include/linux/smp.h:13,
                    from arch/arm64/include/asm/arch_timer.h:18,
                    from arch/arm64/include/asm/timex.h:8,
                    from include/linux/timex.h:67,
                    from include/linux/time32.h:13,
                    from include/linux/time.h:60,
                    from arch/arm64/include/asm/stat.h:12,
                    from include/linux/stat.h:6,
                    from include/linux/module.h:13,
                    from fs/omfs/file.c:7:
   fs/omfs/file.c: In function 'omfs_grow_extent':
>> include/linux/fortify-string.h:57:33: warning: writing 16 bytes into a region of size 0 [-Wstringop-overflow=]
      57 | #define __underlying_memcpy     __builtin_memcpy
         |                                 ^
   include/linux/fortify-string.h:648:9: note: in expansion of macro '__underlying_memcpy'
     648 |         __underlying_##op(p, q, __fortify_size);                        \
         |         ^~~~~~~~~~~~~
   include/linux/fortify-string.h:693:26: note: in expansion of macro '__fortify_memcpy_chk'
     693 | #define memcpy(p, q, s)  __fortify_memcpy_chk(p, q, s,                  \
         |                          ^~~~~~~~~~~~~~~~~~~~
   fs/omfs/file.c:170:9: note: in expansion of macro 'memcpy'
     170 |         memcpy(terminator, entry, sizeof(struct omfs_extent_entry));
         |         ^~~~~~
   In file included from fs/omfs/omfs.h:8,
                    from fs/omfs/file.c:11:
   fs/omfs/omfs_fs.h:80:34: note: at offset 16 into destination object 'e_entry' of size 16
      80 |         struct omfs_extent_entry e_entry;       /* start of extent entries */
         |                                  ^~~~~~~


vim +57 include/linux/fortify-string.h

78a498c3a227f2 Alexander Potapenko 2022-10-24  46  
78a498c3a227f2 Alexander Potapenko 2022-10-24  47  #if defined(__SANITIZE_MEMORY__)
78a498c3a227f2 Alexander Potapenko 2022-10-24  48  /*
78a498c3a227f2 Alexander Potapenko 2022-10-24  49   * For KMSAN builds all memcpy/memset/memmove calls should be replaced by the
78a498c3a227f2 Alexander Potapenko 2022-10-24  50   * corresponding __msan_XXX functions.
78a498c3a227f2 Alexander Potapenko 2022-10-24  51   */
78a498c3a227f2 Alexander Potapenko 2022-10-24  52  #include <linux/kmsan_string.h>
78a498c3a227f2 Alexander Potapenko 2022-10-24  53  #define __underlying_memcpy	__msan_memcpy
78a498c3a227f2 Alexander Potapenko 2022-10-24  54  #define __underlying_memmove	__msan_memmove
78a498c3a227f2 Alexander Potapenko 2022-10-24  55  #define __underlying_memset	__msan_memset
78a498c3a227f2 Alexander Potapenko 2022-10-24  56  #else
a28a6e860c6cf2 Francis Laniel      2021-02-25 @57  #define __underlying_memcpy	__builtin_memcpy
a28a6e860c6cf2 Francis Laniel      2021-02-25  58  #define __underlying_memmove	__builtin_memmove
a28a6e860c6cf2 Francis Laniel      2021-02-25  59  #define __underlying_memset	__builtin_memset
78a498c3a227f2 Alexander Potapenko 2022-10-24  60  #endif
78a498c3a227f2 Alexander Potapenko 2022-10-24  61  

:::::: The code at line 57 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>

-- 
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https://github.com/intel/lkp-tests/wiki