[RFC PATCH 1/2] trace: Move data to new section _ftrace_data

[Joe Perches]

Move the data used by tracing to a separate section to
help identify and perhaps control access to tracing data.

Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
 include/trace/trace_events.h | 31 ++++++++++++++++++++++---------
 kernel/trace/trace_export.c  | 10 +++++++---
 2 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h
index 502c7b..361999f 100644
--- a/include/trace/trace_events.h
+++ b/include/trace/trace_events.h
@@ -369,7 +369,9 @@ trace_raw_output_##call(struct trace_iterator *iter, int flags,		\
 									\
 	return trace_handle_return(s);					\
 }									\
-static struct trace_event_functions trace_event_type_funcs_##call = {	\
+static struct trace_event_functions					\
+__attribute__((section("_ftrace_data")))				\
+trace_event_type_funcs_##call = {					\
 	.trace			= trace_raw_output_##call,		\
 };
 
@@ -439,9 +441,12 @@ static struct trace_event_functions trace_event_type_funcs_##call = {	\
 
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, func, print)	\
-static struct trace_event_fields trace_event_fields_##call[] = {	\
+static struct trace_event_fields					\
+__attribute__((section("_ftrace_data")))				\
+trace_event_fields_##call[] = {						\
 	tstruct								\
-	{} };
+	{}								\
+};
 
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, name, proto, args)
@@ -746,7 +751,8 @@ static inline void ftrace_test_probe_##call(void)			\
 #undef DECLARE_EVENT_CLASS
 #define DECLARE_EVENT_CLASS(call, proto, args, tstruct, assign, print)	\
 _TRACE_PERF_PROTO(call, PARAMS(proto));					\
-static char print_fmt_##call[] = print;					\
+static char __attribute__((section("_ftrace_data")))			\
+print_fmt_##call[] = print;						\
 static struct trace_event_class __used __refdata event_class_##call = { \
 	.system			= TRACE_SYSTEM_STRING,			\
 	.fields_array		= trace_event_fields_##call,		\
@@ -760,7 +766,9 @@ static struct trace_event_class __used __refdata event_class_##call = { \
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, call, proto, args)			\
 									\
-static struct trace_event_call __used event_##call = {			\
+static struct trace_event_call __used					\
+__attribute__((section("_ftrace_data")))				\
+event_##call = {							\
 	.class			= &event_class_##template,		\
 	{								\
 		.tp			= &__tracepoint_##call,		\
@@ -770,14 +778,18 @@ static struct trace_event_call __used event_##call = {			\
 	.flags			= TRACE_EVENT_FL_TRACEPOINT,		\
 };									\
 static struct trace_event_call __used					\
-__attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
+__attribute__((section("_ftrace_events")))				\
+*__event_##call = &event_##call
 
 #undef DEFINE_EVENT_PRINT
 #define DEFINE_EVENT_PRINT(template, call, proto, args, print)		\
 									\
-static char print_fmt_##call[] = print;					\
+static char __attribute__((section("_ftrace_data")))			\
+print_fmt_##call[] = print;						\
 									\
-static struct trace_event_call __used event_##call = {			\
+static struct trace_event_call __used					\
+__attribute__((section("_ftrace_data")))				\
+event_##call = {							\
 	.class			= &event_class_##template,		\
 	{								\
 		.tp			= &__tracepoint_##call,		\
@@ -787,6 +799,7 @@ static struct trace_event_call __used event_##call = {			\
 	.flags			= TRACE_EVENT_FL_TRACEPOINT,		\
 };									\
 static struct trace_event_call __used					\
-__attribute__((section("_ftrace_events"))) *__event_##call = &event_##call
+__attribute__((section("_ftrace_events")))				\
+*__event_##call = &event_##call
 
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
diff --git a/kernel/trace/trace_export.c b/kernel/trace/trace_export.c
index 77ce5a..90af7c9 100644
--- a/kernel/trace/trace_export.c
+++ b/kernel/trace/trace_export.c
@@ -111,9 +111,12 @@ static void __always_unused ____ftrace_check_##name(void)		\
 
 #undef FTRACE_ENTRY
 #define FTRACE_ENTRY(name, struct_name, id, tstruct, print)		\
-static struct trace_event_fields ftrace_event_fields_##name[] = {	\
+static struct trace_event_fields					\
+__attribute__((section("_ftrace_data")))				\
+ftrace_event_fields_##name[] = {					\
 	tstruct								\
-	{} };
+	{}								\
+};
 
 #include "trace_entries.h"
 
@@ -150,7 +153,8 @@ static struct trace_event_class __refdata event_class_ftrace_##call = {	\
 	.reg			= regfn,				\
 };									\
 									\
-struct trace_event_call __used event_##call = {				\
+struct trace_event_call __used __attribute((section("_ftrace_data")))	\
+event_##call = {							\
 	.class			= &event_class_ftrace_##call,		\
 	{								\
 		.name			= #call,			\
-- 
2.24.0