1 files changed, 185 insertions, 100 deletions

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index d128f65778e..3f972ad98d0 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -60,10 +60,8 @@ int trace_define_field(struct ftrace_event_call *call, const char *type,
 	return 0;
 
 err:
-	if (field) {
+	if (field)
 		kfree(field->name);
-		kfree(field->type);
-	}
 	kfree(field);
 
 	return -ENOMEM;
@@ -78,7 +76,7 @@ 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;
@@ -91,11 +89,8 @@ int trace_define_common_fields(struct ftrace_event_call *call)
 
 	return ret;
 }
-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;
 
@@ -107,27 +102,49 @@ static void trace_destroy_fields(struct ftrace_event_call *call)
 	}
 }
 
-#endif /* CONFIG_MODULES */
+int trace_event_raw_init(struct ftrace_event_call *call)
+{
+	int id;
 
-static void ftrace_event_enable_disable(struct ftrace_event_call *call,
+	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) {
 			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);
+			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)
@@ -406,7 +423,7 @@ 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;
 
@@ -416,7 +433,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
 
 	*ppos += cnt;
 
-	return cnt;
+	return ret ? ret : cnt;
 }
 
 static ssize_t
@@ -501,41 +518,16 @@ out:
 	return ret;
 }
 
-extern char *__bad_type_size(void);
-
-#undef FIELD
-#define FIELD(type, name)						\
-	sizeof(type) != sizeof(field.name) ? __bad_type_size() :	\
-	#type, "common_" #name, offsetof(typeof(field), name),		\
-		sizeof(field.name)
-
-static int trace_write_header(struct trace_seq *s)
-{
-	struct trace_entry field;
-
-	/* struct trace_entry */
-	return trace_seq_printf(s,
-				"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
-				"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
-				"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
-				"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
-				"\tfield:%s %s;\toffset:%zu;\tsize:%zu;\n"
-				"\n",
-				FIELD(unsigned short, type),
-				FIELD(unsigned char, flags),
-				FIELD(unsigned char, preempt_count),
-				FIELD(int, pid),
-				FIELD(int, lock_depth));
-}
-
 static ssize_t
 event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
 		  loff_t *ppos)
 {
 	struct ftrace_event_call *call = filp->private_data;
+	struct ftrace_event_field *field;
 	struct trace_seq *s;
+	int common_field_count = 5;
 	char *buf;
-	int r;
+	int r = 0;
 
 	if (*ppos)
 		return 0;
@@ -546,14 +538,48 @@ event_format_read(struct file *filp, char __user *ubuf, size_t cnt,
 
 	trace_seq_init(s);
 
-	/* If any of the first writes fail, so will the show_format. */
-
 	trace_seq_printf(s, "name: %s\n", call->name);
 	trace_seq_printf(s, "ID: %d\n", call->id);
 	trace_seq_printf(s, "format:\n");
-	trace_write_header(s);
 
-	r = call->show_format(call, s);
+	list_for_each_entry_reverse(field, &call->fields, link) {
+		/*
+		 * Smartly shows the array type(except dynamic array).
+		 * Normal:
+		 *	field:TYPE VAR
+		 * If TYPE := TYPE[LEN], it is shown:
+		 *	field:TYPE VAR[LEN]
+		 */
+		const char *array_descriptor = strchr(field->type, '[');
+
+		if (!strncmp(field->type, "__data_loc", 10))
+			array_descriptor = NULL;
+
+		if (!array_descriptor) {
+			r = trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;"
+					"\tsize:%u;\tsigned:%d;\n",
+					field->type, field->name, field->offset,
+					field->size, !!field->is_signed);
+		} else {
+			r = trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;"
+					"\tsize:%u;\tsigned:%d;\n",
+					(int)(array_descriptor - field->type),
+					field->type, field->name,
+					array_descriptor, field->offset,
+					field->size, !!field->is_signed);
+		}
+
+		if (--common_field_count == 0)
+			r = trace_seq_printf(s, "\n");
+
+		if (!r)
+			break;
+	}
+
+	if (r)
+		r = trace_seq_printf(s, "\nprint fmt: %s\n",
+				call->print_fmt);
+
 	if (!r) {
 		/*
 		 * ug!  The format output is bigger than a PAGE!!
@@ -878,9 +904,9 @@ event_subsystem_dir(const char *name, struct dentry *d_events)
 			   "'%s/filter' entry\n", name);
 	}
 
-	entry = trace_create_file("enable", 0644, system->entry,
-				  (void *)system->name,
-				  &ftrace_system_enable_fops);
+	trace_create_file("enable", 0644, system->entry,
+			  (void *)system->name,
+			  &ftrace_system_enable_fops);
 
 	return system->entry;
 }
@@ -892,7 +918,6 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
 		 const struct file_operations *filter,
 		 const struct file_operations *format)
 {
-	struct dentry *entry;
 	int ret;
 
 	/*
@@ -910,55 +935,72 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
 	}
 
 	if (call->regfunc)
-		entry = trace_create_file("enable", 0644, call->dir, call,
-					  enable);
+		trace_create_file("enable", 0644, call->dir, call,
+				  enable);
 
 	if (call->id && call->profile_enable)
-		entry = trace_create_file("id", 0444, call->dir, call,
-					  id);
+		trace_create_file("id", 0444, call->dir, call,
+		 		  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);
 			return ret;
 		}
-		entry = trace_create_file("filter", 0644, call->dir, call,
-					  filter);
+		trace_create_file("filter", 0644, call->dir, call,
+				  filter);
 	}
 
-	/* A trace may not want to export its format */
-	if (!call->show_format)
-		return 0;
-
-	entry = trace_create_file("format", 0444, call->dir, call,
-				  format);
+	trace_create_file("format", 0444, call->dir, call,
+			  format);
 
 	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 +1028,53 @@ 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 +1132,7 @@ 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 +1150,11 @@ 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 +1168,7 @@ 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 +1286,7 @@ 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 +1294,12 @@ 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) {