ftrace: ensure every event gets an id

Impact: widen user-space visibe event IDs to all events

Previously only TRACE_EVENT events got ids, because only they
generated raw output which needs to be demuxed from the trace.

In order to provide a unique ID for each event, register everybody,
regardless.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20090319194233.464914218@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 19 insertions, 1 deletions

diff --git a/kernel/trace/trace_events_stage_3.h b/kernel/trace/trace_events_stage_3.h
index ae2e323df0c7..4c26d97b4508 100644
--- a/kernel/trace/trace_events_stage_3.h
+++ b/kernel/trace/trace_events_stage_3.h
@@ -130,7 +130,19 @@ static void ftrace_unreg_event_##call(void)				\
 {                                                                       \
         unregister_trace_##call(ftrace_event_##call);                   \
 }                                                                       \
-
+                                                                        \
+static struct ftrace_event_call event_##call;                           \
+                                                                        \
+static int ftrace_init_event_##call(void)                               \
+{                                                                       \
+        int id;                                                         \
+                                                                        \
+        id = register_ftrace_event(NULL);                               \
+        if (!id)                                                        \
+                return -ENODEV;                                         \
+        event_##call.id = id;                                           \
+        return 0;                                                       \
+}
 
 #undef TRACE_FORMAT
 #define TRACE_FORMAT(call, proto, args, fmt)                            \
@@ -140,6 +152,7 @@ __attribute__((__aligned__(4)))						\
 __attribute__((section("_ftrace_events"))) event_##call = {             \
         .name                   = #call,                                \
         .system                 = __stringify(TRACE_SYSTEM),            \
+        .raw_init               = ftrace_init_event_##call,             \
         .regfunc                = ftrace_reg_event_##call,              \
         .unregfunc              = ftrace_unreg_event_##call,            \
 }
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index b45141748af5..19261fdd2455 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -481,6 +481,11 @@ int register_ftrace_event(struct trace_event *event)
 
         mutex_lock(&trace_event_mutex);
 
+        if (!event) {
+                ret = next_event_type++;
+                goto out;
+        }
+
         if (!event->type)
                 event->type = next_event_type++;
         else if (event->type > __TRACE_LAST_TYPE) {