Merge commit 'v2.6.32-rc5' into perf/probes

[karo-tx-linux.git] / kernel / trace / trace_events.c

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index d128f65778e69654207c6d8d7b987bc7837f7541..f2f5064701e53e02e56e22bdcc1c5f07a1f04706 100644 (file)
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -93,9 +93,7 @@ int trace_define_common_fields(struct ftrace_event_call *call)
 }
 EXPORT_SYMBOL_GPL(trace_define_common_fields);
 
-#ifdef CONFIG_MODULES
-
-static void trace_destroy_fields(struct ftrace_event_call *call)
+void trace_destroy_fields(struct ftrace_event_call *call)
 {
        struct ftrace_event_field *field, *next;
 
@@ -107,8 +105,6 @@ static void trace_destroy_fields(struct ftrace_event_call *call)
        }
 }
 
-#endif /* CONFIG_MODULES */
-
 static void ftrace_event_enable_disable(struct ftrace_event_call *call,
                                        int enable)
 {
@@ -117,14 +113,14 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call,
                if (call->enabled) {
                        call->enabled = 0;
                        tracing_stop_cmdline_record();
-                       call->unregfunc(call->data);
+                       call->unregfunc(call);
                }
                break;
        case 1:
                if (!call->enabled) {
                        call->enabled = 1;
                        tracing_start_cmdline_record();
-                       call->regfunc(call->data);
+                       call->regfunc(call);
                }
                break;
        }
@@ -938,27 +934,46 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
        return 0;
 }
 
-#define for_each_event(event, start, end)                      \
-       for (event = start;                                     \
-            (unsigned long)event < (unsigned long)end;         \
-            event++)
+static int __trace_add_event_call(struct ftrace_event_call *call)
+{
+       struct dentry *d_events;
+       int ret;
 
-#ifdef CONFIG_MODULES
+       if (!call->name)
+               return -EINVAL;
 
-static LIST_HEAD(ftrace_module_file_list);
+       if (call->raw_init) {
+               ret = call->raw_init(call);
+               if (ret < 0) {
+                       if (ret != -ENOSYS)
+                               pr_warning("Could not initialize trace "
+                               "events/%s\n", call->name);
+                       return ret;
+               }
+       }
 
-/*
- * Modules must own their file_operations to keep up with
- * reference counting.
- */
-struct ftrace_module_file_ops {
-       struct list_head                list;
-       struct module                   *mod;
-       struct file_operations          id;
-       struct file_operations          enable;
-       struct file_operations          format;
-       struct file_operations          filter;
-};
+       d_events = event_trace_events_dir();
+       if (!d_events)
+               return -ENOENT;
+
+       ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
+                               &ftrace_enable_fops, &ftrace_event_filter_fops,
+                               &ftrace_event_format_fops);
+       if (!ret)
+               list_add(&call->list, &ftrace_events);
+
+       return ret;
+}
+
+/* Add an additional event_call dynamically */
+int trace_add_event_call(struct ftrace_event_call *call)
+{
+       int ret;
+       mutex_lock(&event_mutex);
+       ret = __trace_add_event_call(call);
+       mutex_unlock(&event_mutex);
+       return ret;
+}
 
 static void remove_subsystem_dir(const char *name)
 {
@@ -986,6 +1001,53 @@ static void remove_subsystem_dir(const char *name)
        }
 }
 
+/*
+ * Must be called under locking both of event_mutex and trace_event_mutex.
+ */
+static void __trace_remove_event_call(struct ftrace_event_call *call)
+{
+       ftrace_event_enable_disable(call, 0);
+       if (call->event)
+               __unregister_ftrace_event(call->event);
+       debugfs_remove_recursive(call->dir);
+       list_del(&call->list);
+       trace_destroy_fields(call);
+       destroy_preds(call);
+       remove_subsystem_dir(call->system);
+}
+
+/* Remove an event_call */
+void trace_remove_event_call(struct ftrace_event_call *call)
+{
+       mutex_lock(&event_mutex);
+       down_write(&trace_event_mutex);
+       __trace_remove_event_call(call);
+       up_write(&trace_event_mutex);
+       mutex_unlock(&event_mutex);
+}
+
+#define for_each_event(event, start, end)                      \
+       for (event = start;                                     \
+            (unsigned long)event < (unsigned long)end;         \
+            event++)
+
+#ifdef CONFIG_MODULES
+
+static LIST_HEAD(ftrace_module_file_list);
+
+/*
+ * Modules must own their file_operations to keep up with
+ * reference counting.
+ */
+struct ftrace_module_file_ops {
+       struct list_head                list;
+       struct module                   *mod;
+       struct file_operations          id;
+       struct file_operations          enable;
+       struct file_operations          format;
+       struct file_operations          filter;
+};
+
 static struct ftrace_module_file_ops *
 trace_create_file_ops(struct module *mod)
 {
@@ -1043,7 +1105,7 @@ static void trace_module_add_events(struct module *mod)
                if (!call->name)
                        continue;
                if (call->raw_init) {
-                       ret = call->raw_init();
+                       ret = call->raw_init(call);
                        if (ret < 0) {
                                if (ret != -ENOSYS)
                                        pr_warning("Could not initialize trace "
@@ -1061,10 +1123,11 @@ static void trace_module_add_events(struct module *mod)
                                return;
                }
                call->mod = mod;
-               list_add(&call->list, &ftrace_events);
-               event_create_dir(call, d_events,
-                                &file_ops->id, &file_ops->enable,
-                                &file_ops->filter, &file_ops->format);
+               ret = event_create_dir(call, d_events,
+                                      &file_ops->id, &file_ops->enable,
+                                      &file_ops->filter, &file_ops->format);
+               if (!ret)
+                       list_add(&call->list, &ftrace_events);
        }
 }
 
@@ -1078,14 +1141,7 @@ static void trace_module_remove_events(struct module *mod)
        list_for_each_entry_safe(call, p, &ftrace_events, list) {
                if (call->mod == mod) {
                        found = true;
-                       ftrace_event_enable_disable(call, 0);
-                       if (call->event)
-                               __unregister_ftrace_event(call->event);
-                       debugfs_remove_recursive(call->dir);
-                       list_del(&call->list);
-                       trace_destroy_fields(call);
-                       destroy_preds(call);
-                       remove_subsystem_dir(call->system);
+                       __trace_remove_event_call(call);
                }
        }
 
@@ -1203,7 +1259,7 @@ static __init int event_trace_init(void)
                if (!call->name)
                        continue;
                if (call->raw_init) {
-                       ret = call->raw_init();
+                       ret = call->raw_init(call);
                        if (ret < 0) {
                                if (ret != -ENOSYS)
                                        pr_warning("Could not initialize trace "
@@ -1211,10 +1267,12 @@ static __init int event_trace_init(void)
                                continue;
                        }
                }
-               list_add(&call->list, &ftrace_events);
-               event_create_dir(call, d_events, &ftrace_event_id_fops,
-                                &ftrace_enable_fops, &ftrace_event_filter_fops,
-                                &ftrace_event_format_fops);
+               ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
+                                      &ftrace_enable_fops,
+                                      &ftrace_event_filter_fops,
+                                      &ftrace_event_format_fops);
+               if (!ret)
+                       list_add(&call->list, &ftrace_events);
        }
 
        while (true) {