1 files changed, 33 insertions, 8 deletions

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 1d18315dc836..189b09baf4fb 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -78,7 +78,7 @@ EXPORT_SYMBOL_GPL(trace_define_field);
         if (ret)                                                        \
                 return ret;
 
-int trace_define_common_fields(struct ftrace_event_call *call)
+static int trace_define_common_fields(struct ftrace_event_call *call)
 {
         int ret;
         struct trace_entry ent;
@@ -91,7 +91,6 @@ int trace_define_common_fields(struct ftrace_event_call *call)
 
         return ret;
 }
-EXPORT_SYMBOL_GPL(trace_define_common_fields);
 
 void trace_destroy_fields(struct ftrace_event_call *call)
 {
@@ -105,9 +104,25 @@ void trace_destroy_fields(struct ftrace_event_call *call)
         }
 }
 
-static void ftrace_event_enable_disable(struct ftrace_event_call *call,
+int trace_event_raw_init(struct ftrace_event_call *call)
+{
+        int id;
+
+        id = register_ftrace_event(call->event);
+        if (!id)
+                return -ENODEV;
+        call->id = id;
+        INIT_LIST_HEAD(&call->fields);
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(trace_event_raw_init);
+
+static int ftrace_event_enable_disable(struct ftrace_event_call *call,
                                         int enable)
 {
+        int ret = 0;
+
         switch (enable) {
         case 0:
                 if (call->enabled) {
@@ -118,12 +133,20 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call,
                 break;
         case 1:
                 if (!call->enabled) {
-                        call->enabled = 1;
                         tracing_start_cmdline_record();
-                        call->regfunc(call);
+                        ret = call->regfunc(call);
+                        if (ret) {
+                                tracing_stop_cmdline_record();
+                                pr_info("event trace: Could not enable event "
+                                        "%s\n", call->name);
+                                break;
+                        }
+                        call->enabled = 1;
                 }
                 break;
         }
+
+        return ret;
 }
 
 static void ftrace_clear_events(void)
@@ -402,7 +425,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
         case 0:
         case 1:
                 mutex_lock(&event_mutex);
-                ftrace_event_enable_disable(call, val);
+                ret = ftrace_event_enable_disable(call, val);
                 mutex_unlock(&event_mutex);
                 break;
 
@@ -412,7 +435,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 
         *ppos += cnt;
 
-        return cnt;
+        return ret ? ret : cnt;
 }
 
 static ssize_t
@@ -913,7 +936,9 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
                                   id);
 
         if (call->define_fields) {
-                ret = call->define_fields(call);
+                ret = trace_define_common_fields(call);
+                if (!ret)
+                        ret = call->define_fields(call);
                 if (ret < 0) {
                         pr_warning("Could not initialize trace point"
                                    " events/%s\n", call->name);