tracing/events: make struct trace_entry->type to be int type

struct trace_entry->type is unsigned char, while trace event's id is
int type, thus for a event with id >= 256, it's entry->type is cast
to (id % 256), and then we can't see the trace output of this event.

 # insmod trace-events-sample.ko
 # echo foo_bar > /mnt/tracing/set_event
 # cat /debug/tracing/events/trace-events-sample/foo_bar/id
 256
 # cat /mnt/tracing/trace_pipe
           <...>-3548  [001]   215.091142: Unknown type 0
           <...>-3548  [001]   216.089207: Unknown type 0
           <...>-3548  [001]   217.087271: Unknown type 0
           <...>-3548  [001]   218.085332: Unknown type 0

[ Impact: fix output for trace events with id >= 256 ]
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <49EEDB0E.5070207@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

include/linux/ftrace_event.h

@@ -16,7 +16,7 @@ struct dentry;
  *     bash-15816 [01]   235.197585: idle_cpu <- irq_enter
  */
 struct trace_entry {
-	unsigned char		type;
+	int			type;
 	unsigned char		flags;
 	unsigned char		preempt_count;
 	int			pid;
@@ -73,7 +73,7 @@ enum print_line_t {
 
 
 struct ring_buffer_event *
-trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
+trace_current_buffer_lock_reserve(int type, unsigned long len,
 				  unsigned long flags, int pc);
 void trace_current_buffer_unlock_commit(struct ring_buffer_event *event,
 					unsigned long flags, int pc);

include/trace/ftrace.h

@@ -198,7 +198,7 @@ ftrace_define_fields_##call(void)					\
 	struct ftrace_event_call *event_call = &event_##call;		\
 	int ret;							\
 									\
-	__common_field(unsigned char, type);				\
+	__common_field(int, type);					\
 	__common_field(unsigned char, flags);				\
 	__common_field(unsigned char, preempt_count);			\
 	__common_field(int, pid);					\

kernel/trace/trace.c

@@ -838,7 +838,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
 }
 
 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
-						    unsigned char type,
+						    int type,
 						    unsigned long len,
 						    unsigned long flags, int pc)
 {
@@ -881,7 +881,7 @@ void trace_buffer_unlock_commit(struct trace_array *tr,
 }
 
 struct ring_buffer_event *
-trace_current_buffer_lock_reserve(unsigned char type, unsigned long len,
+trace_current_buffer_lock_reserve(int type, unsigned long len,
 				  unsigned long flags, int pc)
 {
 	return trace_buffer_lock_reserve(&global_trace,

kernel/trace/trace.h

@@ -422,7 +422,7 @@ void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
 struct ring_buffer_event;
 
 struct ring_buffer_event *trace_buffer_lock_reserve(struct trace_array *tr,
-						    unsigned char type,
+						    int type,
 						    unsigned long len,
 						    unsigned long flags,
 						    int pc);

kernel/trace/trace_events.c

@@ -398,7 +398,7 @@ static int trace_write_header(struct trace_seq *s)
 				"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
 				"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
 				"\n",
-				FIELD(unsigned char, type),
+				FIELD(int, type),
 				FIELD(unsigned char, flags),
 				FIELD(unsigned char, preempt_count),
 				FIELD(int, pid),