tracing: Fix some section mismatch warnings

As we've added __init annotation to field-defining functions, we should
add __refdata annotation to event_call variables, which reference those
functions.

Link: http://lkml.kernel.org/r/51343C1F.2050502@huawei.com

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

include/trace/ftrace.h

@@ -572,7 +572,7 @@ static inline void ftrace_test_probe_##call(void)			\
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
 _TRACE_PERF_PROTO(call, PARAMS(proto));					\
 static const char print_fmt_##call[] = print;				\
-static struct ftrace_event_class __used event_class_##call = {		\
+static struct ftrace_event_class __used __refdata event_class_##call = { \
 	.system			= __stringify(TRACE_SYSTEM),		\
 	.define_fields		= ftrace_define_fields_##call,		\
 	.fields			= LIST_HEAD_INIT(event_class_##call.fields),\

kernel/trace/trace_export.c

@@ -168,7 +168,7 @@ ftrace_define_fields_##name(struct ftrace_event_call *event_call)	\
 #define FTRACE_ENTRY_REG(call, struct_name, etype, tstruct, print, filter,\
 			 regfn)						\
 									\
-struct ftrace_event_class event_class_ftrace_##call = {			\
+struct ftrace_event_class __refdata event_class_ftrace_##call = {	\
 	.system			= __stringify(TRACE_SYSTEM),		\
 	.define_fields		= ftrace_define_fields_##call,		\
 	.fields			= LIST_HEAD_INIT(event_class_ftrace_##call.fields),\

kernel/trace/trace_syscalls.c

@@ -479,7 +479,7 @@ struct trace_event_functions exit_syscall_print_funcs = {
 	.trace		= print_syscall_exit,
 };
 
-struct ftrace_event_class event_class_syscall_enter = {
+struct ftrace_event_class __refdata event_class_syscall_enter = {
 	.system		= "syscalls",
 	.reg		= syscall_enter_register,
 	.define_fields	= syscall_enter_define_fields,
@@ -487,7 +487,7 @@ struct ftrace_event_class event_class_syscall_enter = {
 	.raw_init	= init_syscall_trace,
 };
 
-struct ftrace_event_class event_class_syscall_exit = {
+struct ftrace_event_class __refdata event_class_syscall_exit = {
 	.system		= "syscalls",
 	.reg		= syscall_exit_register,
 	.define_fields	= syscall_exit_define_fields,