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: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Frederic 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: Ingo Molnar <mingo@elte.hu>

3 files changed, 4 insertions, 4 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b9a3adce9221..b6183bc9ecae 100644
--- a/kernel/trace/trace.c
+++ b/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,
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 247948e81b08..7d55bcf50e49 100644
--- a/kernel/trace/trace.h
+++ b/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);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 9ea55a7dfdec..5d6e879cf875 100644
--- a/kernel/trace/trace_events.c
+++ b/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),