1 files changed, 120 insertions, 122 deletions

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 46439e3bcec4..cbfc306c0159 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -159,7 +159,7 @@ static void *trigger_start(struct seq_file *m, loff_t *pos)
 
 	/* ->stop() is called even if ->start() fails */
 	mutex_lock(&event_mutex);
-	event_file = event_file_data(m->private);
+	event_file = event_file_file(m->private);
 	if (unlikely(!event_file))
 		return ERR_PTR(-ENODEV);
 
@@ -211,12 +211,10 @@ static int event_trigger_regex_open(struct inode *inode, struct file *file)
 	if (ret)
 		return ret;
 
-	mutex_lock(&event_mutex);
+	guard(mutex)(&event_mutex);
 
-	if (unlikely(!event_file_data(file))) {
-		mutex_unlock(&event_mutex);
+	if (unlikely(!event_file_file(file)))
 		return -ENODEV;
-	}
 
 	if ((file->f_mode & FMODE_WRITE) &&
 	    (file->f_flags & O_TRUNC)) {
@@ -239,8 +237,6 @@ static int event_trigger_regex_open(struct inode *inode, struct file *file)
 		}
 	}
 
-	mutex_unlock(&event_mutex);
-
 	return ret;
 }
 
@@ -248,7 +244,6 @@ int trigger_process_regex(struct trace_event_file *file, char *buff)
 {
 	char *command, *next;
 	struct event_command *p;
-	int ret = -EINVAL;
 
 	next = buff = skip_spaces(buff);
 	command = strsep(&next, ": \t");
@@ -259,17 +254,14 @@ int trigger_process_regex(struct trace_event_file *file, char *buff)
 	}
 	command = (command[0] != '!') ? command : command + 1;
 
-	mutex_lock(&trigger_cmd_mutex);
+	guard(mutex)(&trigger_cmd_mutex);
+
 	list_for_each_entry(p, &trigger_commands, list) {
-		if (strcmp(p->name, command) == 0) {
-			ret = p->parse(p, file, buff, command, next);
-			goto out_unlock;
-		}
+		if (strcmp(p->name, command) == 0)
+			return p->parse(p, file, buff, command, next);
 	}
- out_unlock:
-	mutex_unlock(&trigger_cmd_mutex);
 
-	return ret;
+	return -EINVAL;
 }
 
 static ssize_t event_trigger_regex_write(struct file *file,
@@ -278,7 +270,7 @@ static ssize_t event_trigger_regex_write(struct file *file,
 {
 	struct trace_event_file *event_file;
 	ssize_t ret;
-	char *buf;
+	char *buf __free(kfree) = NULL;
 
 	if (!cnt)
 		return 0;
@@ -292,24 +284,18 @@ static ssize_t event_trigger_regex_write(struct file *file,
 
 	strim(buf);
 
-	mutex_lock(&event_mutex);
-	event_file = event_file_data(file);
-	if (unlikely(!event_file)) {
-		mutex_unlock(&event_mutex);
-		kfree(buf);
+	guard(mutex)(&event_mutex);
+
+	event_file = event_file_file(file);
+	if (unlikely(!event_file))
 		return -ENODEV;
-	}
-	ret = trigger_process_regex(event_file, buf);
-	mutex_unlock(&event_mutex);
 
-	kfree(buf);
+	ret = trigger_process_regex(event_file, buf);
 	if (ret < 0)
-		goto out;
+		return ret;
 
 	*ppos += cnt;
-	ret = cnt;
- out:
-	return ret;
+	return cnt;
 }
 
 static int event_trigger_regex_release(struct inode *inode, struct file *file)
@@ -359,20 +345,16 @@ const struct file_operations event_trigger_fops = {
 __init int register_event_command(struct event_command *cmd)
 {
 	struct event_command *p;
-	int ret = 0;
 
-	mutex_lock(&trigger_cmd_mutex);
+	guard(mutex)(&trigger_cmd_mutex);
+
 	list_for_each_entry(p, &trigger_commands, list) {
-		if (strcmp(cmd->name, p->name) == 0) {
-			ret = -EBUSY;
-			goto out_unlock;
-		}
+		if (strcmp(cmd->name, p->name) == 0)
+			return -EBUSY;
 	}
 	list_add(&cmd->list, &trigger_commands);
- out_unlock:
-	mutex_unlock(&trigger_cmd_mutex);
 
-	return ret;
+	return 0;
 }
 
 /*
@@ -382,20 +364,17 @@ __init int register_event_command(struct event_command *cmd)
 __init int unregister_event_command(struct event_command *cmd)
 {
 	struct event_command *p, *n;
-	int ret = -ENODEV;
 
-	mutex_lock(&trigger_cmd_mutex);
+	guard(mutex)(&trigger_cmd_mutex);
+
 	list_for_each_entry_safe(p, n, &trigger_commands, list) {
 		if (strcmp(cmd->name, p->name) == 0) {
-			ret = 0;
 			list_del_init(&p->list);
-			goto out_unlock;
+			return 0;
 		}
 	}
- out_unlock:
-	mutex_unlock(&trigger_cmd_mutex);
 
-	return ret;
+	return -ENODEV;
 }
 
 /**
@@ -573,16 +552,14 @@ static int register_trigger(char *glob,
 	lockdep_assert_held(&event_mutex);
 
 	list_for_each_entry(test, &file->triggers, list) {
-		if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type) {
-			ret = -EEXIST;
-			goto out;
-		}
+		if (test->cmd_ops->trigger_type == data->cmd_ops->trigger_type)
+			return -EEXIST;
 	}
 
 	if (data->ops->init) {
 		ret = data->ops->init(data);
 		if (ret < 0)
-			goto out;
+			return ret;
 	}
 
 	list_add_rcu(&data->list, &file->triggers);
@@ -593,24 +570,15 @@ static int register_trigger(char *glob,
 		list_del_rcu(&data->list);
 		update_cond_flag(file);
 	}
-out:
 	return ret;
 }
 
-/**
- * unregister_trigger - Generic event_command @unreg implementation
- * @glob: The raw string used to register the trigger
- * @test: Trigger-specific data used to find the trigger to remove
- * @file: The trace_event_file associated with the event
- *
- * Common implementation for event trigger unregistration.
- *
- * Usually used directly as the @unreg method in event command
- * implementations.
+/*
+ * True if the trigger was found and unregistered, else false.
  */
-static void unregister_trigger(char *glob,
-			       struct event_trigger_data *test,
-			       struct trace_event_file *file)
+static bool try_unregister_trigger(char *glob,
+				   struct event_trigger_data *test,
+				   struct trace_event_file *file)
 {
 	struct event_trigger_data *data = NULL, *iter;
 
@@ -626,8 +594,32 @@ static void unregister_trigger(char *glob,
 		}
 	}
 
-	if (data && data->ops->free)
-		data->ops->free(data);
+	if (data) {
+		if (data->ops->free)
+			data->ops->free(data);
+
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * unregister_trigger - Generic event_command @unreg implementation
+ * @glob: The raw string used to register the trigger
+ * @test: Trigger-specific data used to find the trigger to remove
+ * @file: The trace_event_file associated with the event
+ *
+ * Common implementation for event trigger unregistration.
+ *
+ * Usually used directly as the @unreg method in event command
+ * implementations.
+ */
+static void unregister_trigger(char *glob,
+			       struct event_trigger_data *test,
+			       struct trace_event_file *file)
+{
+	try_unregister_trigger(glob, test, file);
 }
 
 /*
@@ -775,7 +767,7 @@ int event_trigger_separate_filter(char *param_and_filter, char **param,
 	if (!param_and_filter) {
 		if (param_required)
 			ret = -EINVAL;
-		goto out;
+		return ret;
 	}
 
 	/*
@@ -786,7 +778,7 @@ int event_trigger_separate_filter(char *param_and_filter, char **param,
 	 */
 	if (!param_required && param_and_filter && !isdigit(param_and_filter[0])) {
 		*filter = param_and_filter;
-		goto out;
+		return ret;
 	}
 
 	/*
@@ -804,12 +796,11 @@ int event_trigger_separate_filter(char *param_and_filter, char **param,
 		if (!**filter)
 			*filter = NULL;
 	}
-out:
 	return ret;
 }
 
 /**
- * event_trigger_alloc - allocate and init event_trigger_data for a trigger
+ * trigger_data_alloc - allocate and init event_trigger_data for a trigger
  * @cmd_ops: The event_command operations for the trigger
  * @cmd: The cmd string
  * @param: The param string
@@ -820,17 +811,17 @@ out:
  * trigger_ops to assign to the event_trigger_data.  @private_data can
  * also be passed in and associated with the event_trigger_data.
  *
- * Use event_trigger_free() to free an event_trigger_data object.
+ * Use trigger_data_free() to free an event_trigger_data object.
  *
  * Return: The trigger_data object success, NULL otherwise
  */
-struct event_trigger_data *event_trigger_alloc(struct event_command *cmd_ops,
-					       char *cmd,
-					       char *param,
-					       void *private_data)
+struct event_trigger_data *trigger_data_alloc(struct event_command *cmd_ops,
+					      char *cmd,
+					      char *param,
+					      void *private_data)
 {
 	struct event_trigger_data *trigger_data;
-	struct event_trigger_ops *trigger_ops;
+	const struct event_trigger_ops *trigger_ops;
 
 	trigger_ops = cmd_ops->get_trigger_ops(cmd, param);
 
@@ -994,15 +985,14 @@ event_trigger_parse(struct event_command *cmd_ops,
 		return ret;
 
 	ret = -ENOMEM;
-	trigger_data = event_trigger_alloc(cmd_ops, cmd, param, file);
+	trigger_data = trigger_data_alloc(cmd_ops, cmd, param, file);
 	if (!trigger_data)
-		goto out;
+		return ret;
 
 	if (remove) {
 		event_trigger_unregister(cmd_ops, file, glob+1, trigger_data);
-		kfree(trigger_data);
-		ret = 0;
-		goto out;
+		trigger_data_free(trigger_data);
+		return 0;
 	}
 
 	ret = event_trigger_parse_num(param, trigger_data);
@@ -1022,13 +1012,12 @@ event_trigger_parse(struct event_command *cmd_ops,
 
 	/* Down the counter of trigger_data or free it if not used anymore */
 	event_trigger_free(trigger_data);
- out:
 	return ret;
 
  out_free:
 	event_trigger_reset_filter(cmd_ops, trigger_data);
-	kfree(trigger_data);
-	goto out;
+	trigger_data_free(trigger_data);
+	return ret;
 }
 
 /**
@@ -1062,10 +1051,10 @@ int set_trigger_filter(char *filter_str,
 	s = strsep(&filter_str, " \t");
 
 	if (!strlen(s) || strcmp(s, "if") != 0)
-		goto out;
+		return ret;
 
 	if (!filter_str)
-		goto out;
+		return ret;
 
 	/* The filter is for the 'trigger' event, not the triggered event */
 	ret = create_event_filter(file->tr, file->event_call,
@@ -1109,7 +1098,6 @@ int set_trigger_filter(char *filter_str,
 			ret = -ENOMEM;
 		}
 	}
- out:
 	return ret;
 }
 
@@ -1372,38 +1360,38 @@ traceoff_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 				   data->filter_str);
 }
 
-static struct event_trigger_ops traceon_trigger_ops = {
+static const struct event_trigger_ops traceon_trigger_ops = {
 	.trigger		= traceon_trigger,
 	.print			= traceon_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops traceon_count_trigger_ops = {
+static const struct event_trigger_ops traceon_count_trigger_ops = {
 	.trigger		= traceon_count_trigger,
 	.print			= traceon_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops traceoff_trigger_ops = {
+static const struct event_trigger_ops traceoff_trigger_ops = {
 	.trigger		= traceoff_trigger,
 	.print			= traceoff_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops traceoff_count_trigger_ops = {
+static const struct event_trigger_ops traceoff_count_trigger_ops = {
 	.trigger		= traceoff_count_trigger,
 	.print			= traceoff_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
 onoff_get_trigger_ops(char *cmd, char *param)
 {
-	struct event_trigger_ops *ops;
+	const struct event_trigger_ops *ops;
 
 	/* we register both traceon and traceoff to this callback */
 	if (strcmp(cmd, "traceon") == 0)
@@ -1470,10 +1458,23 @@ register_snapshot_trigger(char *glob,
 			  struct event_trigger_data *data,
 			  struct trace_event_file *file)
 {
-	if (tracing_alloc_snapshot_instance(file->tr) != 0)
-		return 0;
+	int ret = tracing_arm_snapshot(file->tr);
+
+	if (ret < 0)
+		return ret;
+
+	ret = register_trigger(glob, data, file);
+	if (ret < 0)
+		tracing_disarm_snapshot(file->tr);
+	return ret;
+}
 
-	return register_trigger(glob, data, file);
+static void unregister_snapshot_trigger(char *glob,
+					struct event_trigger_data *data,
+					struct trace_event_file *file)
+{
+	if (try_unregister_trigger(glob, data, file))
+		tracing_disarm_snapshot(file->tr);
 }
 
 static int
@@ -1483,21 +1484,21 @@ snapshot_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 				   data->filter_str);
 }
 
-static struct event_trigger_ops snapshot_trigger_ops = {
+static const struct event_trigger_ops snapshot_trigger_ops = {
 	.trigger		= snapshot_trigger,
 	.print			= snapshot_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops snapshot_count_trigger_ops = {
+static const struct event_trigger_ops snapshot_count_trigger_ops = {
 	.trigger		= snapshot_count_trigger,
 	.print			= snapshot_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
 snapshot_get_trigger_ops(char *cmd, char *param)
 {
 	return param ? &snapshot_count_trigger_ops : &snapshot_trigger_ops;
@@ -1508,7 +1509,7 @@ static struct event_command trigger_snapshot_cmd = {
 	.trigger_type		= ETT_SNAPSHOT,
 	.parse			= event_trigger_parse,
 	.reg			= register_snapshot_trigger,
-	.unreg			= unregister_trigger,
+	.unreg			= unregister_snapshot_trigger,
 	.get_trigger_ops	= snapshot_get_trigger_ops,
 	.set_filter		= set_trigger_filter,
 };
@@ -1552,7 +1553,7 @@ stacktrace_trigger(struct event_trigger_data *data,
 	struct trace_event_file *file = data->private_data;
 
 	if (file)
-		__trace_stack(file->tr, tracing_gen_ctx(), STACK_SKIP);
+		__trace_stack(file->tr, tracing_gen_ctx_dec(), STACK_SKIP);
 	else
 		trace_dump_stack(STACK_SKIP);
 }
@@ -1578,21 +1579,21 @@ stacktrace_trigger_print(struct seq_file *m, struct event_trigger_data *data)
 				   data->filter_str);
 }
 
-static struct event_trigger_ops stacktrace_trigger_ops = {
+static const struct event_trigger_ops stacktrace_trigger_ops = {
 	.trigger		= stacktrace_trigger,
 	.print			= stacktrace_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops stacktrace_count_trigger_ops = {
+static const struct event_trigger_ops stacktrace_count_trigger_ops = {
 	.trigger		= stacktrace_count_trigger,
 	.print			= stacktrace_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_trigger_free,
 };
 
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
 stacktrace_get_trigger_ops(char *cmd, char *param)
 {
 	return param ? &stacktrace_count_trigger_ops : &stacktrace_trigger_ops;
@@ -1703,28 +1704,28 @@ void event_enable_trigger_free(struct event_trigger_data *data)
 	}
 }
 
-static struct event_trigger_ops event_enable_trigger_ops = {
+static const struct event_trigger_ops event_enable_trigger_ops = {
 	.trigger		= event_enable_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static struct event_trigger_ops event_enable_count_trigger_ops = {
+static const struct event_trigger_ops event_enable_count_trigger_ops = {
 	.trigger		= event_enable_count_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static struct event_trigger_ops event_disable_trigger_ops = {
+static const struct event_trigger_ops event_disable_trigger_ops = {
 	.trigger		= event_enable_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
 	.free			= event_enable_trigger_free,
 };
 
-static struct event_trigger_ops event_disable_count_trigger_ops = {
+static const struct event_trigger_ops event_disable_count_trigger_ops = {
 	.trigger		= event_enable_count_trigger,
 	.print			= event_enable_trigger_print,
 	.init			= event_trigger_init,
@@ -1764,7 +1765,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 	ret = -EINVAL;
 	event_enable_file = find_event_file(tr, system, event);
 	if (!event_enable_file)
-		goto out;
+		return ret;
 
 #ifdef CONFIG_HIST_TRIGGERS
 	hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) ||
@@ -1779,16 +1780,16 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 
 	enable_data = kzalloc(sizeof(*enable_data), GFP_KERNEL);
 	if (!enable_data)
-		goto out;
+		return ret;
 
 	enable_data->hist = hist;
 	enable_data->enable = enable;
 	enable_data->file = event_enable_file;
 
-	trigger_data = event_trigger_alloc(cmd_ops, cmd, param, enable_data);
+	trigger_data = trigger_data_alloc(cmd_ops, cmd, param, enable_data);
 	if (!trigger_data) {
 		kfree(enable_data);
-		goto out;
+		return ret;
 	}
 
 	if (remove) {
@@ -1796,7 +1797,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 		kfree(trigger_data);
 		kfree(enable_data);
 		ret = 0;
-		goto out;
+		return ret;
 	}
 
 	/* Up the trigger_data count to make sure nothing frees it on failure */
@@ -1826,7 +1827,6 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 		goto out_disable;
 
 	event_trigger_free(trigger_data);
- out:
 	return ret;
  out_disable:
 	trace_event_enable_disable(event_enable_file, 0, 1);
@@ -1837,7 +1837,7 @@ int event_enable_trigger_parse(struct event_command *cmd_ops,
 	event_trigger_free(trigger_data);
 	kfree(enable_data);
 
-	goto out;
+	return ret;
 }
 
 int event_enable_register_trigger(char *glob,
@@ -1857,15 +1857,14 @@ int event_enable_register_trigger(char *glob,
 		    (test->cmd_ops->trigger_type ==
 		     data->cmd_ops->trigger_type) &&
 		    (test_enable_data->file == enable_data->file)) {
-			ret = -EEXIST;
-			goto out;
+			return -EEXIST;
 		}
 	}
 
 	if (data->ops->init) {
 		ret = data->ops->init(data);
 		if (ret < 0)
-			goto out;
+			return ret;
 	}
 
 	list_add_rcu(&data->list, &file->triggers);
@@ -1876,7 +1875,6 @@ int event_enable_register_trigger(char *glob,
 		list_del_rcu(&data->list);
 		update_cond_flag(file);
 	}
-out:
 	return ret;
 }
 
@@ -1908,10 +1906,10 @@ void event_enable_unregister_trigger(char *glob,
 		data->ops->free(data);
 }
 
-static struct event_trigger_ops *
+static const struct event_trigger_ops *
 event_enable_get_trigger_ops(char *cmd, char *param)
 {
-	struct event_trigger_ops *ops;
+	const struct event_trigger_ops *ops;
 	bool enable;
 
 #ifdef CONFIG_HIST_TRIGGERS