arch/x86/purgatory/purgatory.c:76:6: warning: no previous prototype for 'warn'

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   dd0d718152e4c65b173070d48ea9dfc06894c3e5
commit: b059f801a937d164e03b33c1848bb3dca67c0b04 x86/purgatory: Use CFLAGS_REMOVE rather than reset KBUILD_CFLAGS
date:   11 months ago
config: x86_64-randconfig-r015-20200623 (attached as .config)
compiler: gcc-5 (Ubuntu 5.5.0-12ubuntu1) 5.5.0 20171010
reproduce (this is a W=1 build):
        git checkout b059f801a937d164e03b33c1848bb3dca67c0b04
        # save the attached .config to linux build tree
        make W=1 ARCH=x86_64 

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

All warnings (new ones prefixed by >>):

>> arch/x86/purgatory/purgatory.c:76:6: warning: no previous prototype for 'warn' [-Wmissing-prototypes]
    void warn(const char *msg) {}
         ^
--
   In file included from arch/x86/boot/compressed/string.c:11:0:
>> arch/x86/boot/compressed/../string.c:43:5: warning: no previous prototype for 'bcmp' [-Wmissing-prototypes]
    int bcmp(const void *s1, const void *s2, size_t len)
        ^
>> arch/x86/boot/compressed/../string.c:146:6: warning: no previous prototype for 'simple_strtol' [-Wmissing-prototypes]
    long simple_strtol(const char *cp, char **endp, unsigned int base)
         ^
>> arch/x86/boot/compressed/string.c:53:7: warning: no previous prototype for 'memmove' [-Wmissing-prototypes]
    void *memmove(void *dest, const void *src, size_t n)
          ^

vim +/warn +76 arch/x86/purgatory/purgatory.c

4ce97317f41d385 Nick Desaulniers 2019-08-07  71  
4ce97317f41d385 Nick Desaulniers 2019-08-07  72  /*
4ce97317f41d385 Nick Desaulniers 2019-08-07  73   * Defined in order to reuse memcpy() and memset() from
4ce97317f41d385 Nick Desaulniers 2019-08-07  74   * arch/x86/boot/compressed/string.c
4ce97317f41d385 Nick Desaulniers 2019-08-07  75   */
4ce97317f41d385 Nick Desaulniers 2019-08-07 @76  void warn(const char *msg) {}

:::::: The code at line 76 was first introduced by commit
:::::: 4ce97317f41d38584fb93578e922fcd19e535f5b x86/purgatory: Do not use __builtin_memcpy and __builtin_memset

:::::: TO: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
:::::: CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

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

Attachment: .config.gz
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