ftrace: Allow module init functions to be traced

Allow for module init sections to be traced as well as core kernel init
sections. Now that filtering modules functions can be stored, for when they
are loaded, it makes sense to be able to trace them.

Cc: Jessica Yu <jeyu@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kernel/trace/ftrace.c

@@ -5752,7 +5752,8 @@ void ftrace_release_mod(struct module *mod)
 	last_pg = &ftrace_pages_start;
 	for (pg = ftrace_pages_start; pg; pg = *last_pg) {
 		rec = &pg->records[0];
-		if (within_module_core(rec->ip, mod)) {
+		if (within_module_core(rec->ip, mod) ||
+		    within_module_init(rec->ip, mod)) {
 			/*
 			 * As core pages are first, the first
 			 * page should never be a module page.
@@ -5821,7 +5822,8 @@ void ftrace_module_enable(struct module *mod)
 		 * not part of this module, then skip this pg,
 		 * which the "break" will do.
 		 */
-		if (!within_module_core(rec->ip, mod))
+		if (!within_module_core(rec->ip, mod) &&
+		    !within_module_init(rec->ip, mod))
 			break;
 
 		cnt = 0;