While compiling for my yeeloong2 laptop, I hit this compile error. As warnings are set for errors, if we define ftrace_modify_code_2(), we must use it. As MIPS 64 does not use this function, it requires being commented out via an #ifndef CONFIG_64bit. Otherwise you get this error: CC arch/mips/kernel/ftrace.o cc1: warnings being treated as errors /work/autotest/nobackup/mips-test.git/arch/mips/kernel/ftrace.c:98:12: error: 'ftrace_modify_code_2' defined but not used make[3]: *** [arch/mips/kernel/ftrace.o] Error 1 make[2]: *** [arch/mips/kernel] Error 2 make[2]: *** Waiting for unfinished jobs.... make[1]: *** [arch/mips] Error 2 make[1]: *** Waiting for unfinished jobs.... Cc: Al Cooper <alcooperx@xxxxxxxxx> Cc: David Daney <ddaney.cvm@xxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> diff --git a/arch/mips/kernel/ftrace.c b/arch/mips/kernel/ftrace.c index 6bcb678..83fa146 100644 --- a/arch/mips/kernel/ftrace.c +++ b/arch/mips/kernel/ftrace.c @@ -95,6 +95,7 @@ static int ftrace_modify_code(unsigned long ip, unsigned int new_code) return 0; } +#ifndef CONFIG_64BIT static int ftrace_modify_code_2(unsigned long ip, unsigned int new_code1, unsigned int new_code2) { @@ -110,6 +111,7 @@ static int ftrace_modify_code_2(unsigned long ip, unsigned int new_code1, flush_icache_range(ip, ip + 8); /* original ip + 12 */ return 0; } +#endif /* * The details about the calling site of mcount on MIPS