On some arch, the FTRACE_WITH_REGS is implemented with gcc's -fpatchable-function-entry (=2), gcc adds 2 NOPs at the beginning of each function, so this makes the MCOUNT_ADDR useless. In ftrace common framework, MCOUNT_ADDR is mostly used to "init" the nop, so let's introcude ftrace_call_init().
Signed-off-by: Jisheng Zhang <jisheng.zh...@synaptics.com> --- include/linux/ftrace.h | 1 + kernel/trace/ftrace.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 8a8cb3c401b2..8175ffb671f0 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -458,6 +458,7 @@ extern void ftrace_regs_caller(void); extern void ftrace_call(void); extern void ftrace_regs_call(void); extern void mcount_call(void); +extern int ftrace_call_init(struct module *mod, struct dyn_ftrace *rec); void ftrace_modify_all_code(int command); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index eca34503f178..9df5a66a6811 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2500,7 +2500,11 @@ ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec) if (unlikely(ftrace_disabled)) return 0; +#ifdef MCOUNT_ADDR ret = ftrace_make_nop(mod, rec, MCOUNT_ADDR); +#else + ret = ftrace_call_init(mod, rec); +#endif if (ret) { ftrace_bug_type = FTRACE_BUG_INIT; ftrace_bug(ret, rec); -- 2.23.0.rc1