ppc64_defconfig Werror: no previous prototype on arch/powerpc/kernel/ftrace.c

[Bagas Sanjaya]

Greetings,

I did ppc64_defconfig build (gcc 11.2.0) on current master at commit
46cf2c613f4b10 ("Merge tag 'pinctrl-v5.18-2'
of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl"),
and it errored out early like this:

  CC      arch/powerpc/kernel/trace/ftrace.o
arch/powerpc/kernel/trace/ftrace.c:978:7: error: no previous prototype for ‘arch_ftrace_match_adjust’ [-Werror=missing-prototypes]
  978 | char *arch_ftrace_match_adjust(char *str, const char *search)
      |       ^~~~~~~~~~~~~~~~~~~~~~~~
  CC      init/init_task.o
cc1: all warnings being treated as errors
make[3]: *** [scripts/Makefile.build:288: arch/powerpc/kernel/trace/ftrace.o] Error 1
make[2]: *** [scripts/Makefile.build:550: arch/powerpc/kernel/trace] Error 2
make[1]: *** [scripts/Makefile.build:550: arch/powerpc/kernel] Error 2
make: *** [Makefile:1834: arch/powerpc] Error 2

The code in question is introduced by commit 7132e2d669bd42 ("ftrace:
Match dot symbols when searching functions on ppc64").

Reported-by: Bagas Sanjaya <bagasdotme@xxxxxxxxx>

-- 
An old man doll... just what I always wanted! - Clara