Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 2cd53ca..e913d41 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -116,9 +116,10 @@
 {
 	struct trace_event_file *event_file = event_file_data(m->private);
 
-	if (t == SHOW_AVAILABLE_TRIGGERS)
+	if (t == SHOW_AVAILABLE_TRIGGERS) {
+		(*pos)++;
 		return NULL;
-
+	}
 	return seq_list_next(t, &event_file->triggers, pos);
 }
 
@@ -215,11 +216,17 @@
 
 static int trigger_process_regex(struct trace_event_file *file, char *buff)
 {
-	char *command, *next = buff;
+	char *command, *next;
 	struct event_command *p;
 	int ret = -EINVAL;
 
+	next = buff = skip_spaces(buff);
 	command = strsep(&next, ": \t");
+	if (next) {
+		next = skip_spaces(next);
+		if (!*next)
+			next = NULL;
+	}
 	command = (command[0] != '!') ? command : command + 1;
 
 	mutex_lock(&trigger_cmd_mutex);
@@ -501,7 +508,9 @@
 	struct event_trigger_data *data;
 	bool set_cond = false;
 
-	list_for_each_entry_rcu(data, &file->triggers, list) {
+	lockdep_assert_held(&event_mutex);
+
+	list_for_each_entry(data, &file->triggers, list) {
 		if (data->filter || event_command_post_trigger(data->cmd_ops) ||
 		    event_command_needs_rec(data->cmd_ops)) {
 			set_cond = true;
@@ -536,7 +545,9 @@
 	struct event_trigger_data *test;
 	int ret = 0;
 
-	list_for_each_entry_rcu(test, &file->triggers, list) {
+	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;
@@ -581,7 +592,9 @@
 	struct event_trigger_data *data;
 	bool unregistered = false;
 
-	list_for_each_entry_rcu(data, &file->triggers, list) {
+	lockdep_assert_held(&event_mutex);
+
+	list_for_each_entry(data, &file->triggers, list) {
 		if (data->cmd_ops->trigger_type == test->cmd_ops->trigger_type) {
 			unregistered = true;
 			list_del_rcu(&data->list);
@@ -623,8 +636,14 @@
 	int ret;
 
 	/* separate the trigger from the filter (t:n [if filter]) */
-	if (param && isdigit(param[0]))
+	if (param && isdigit(param[0])) {
 		trigger = strsep(&param, " \t");
+		if (param) {
+			param = skip_spaces(param);
+			if (!*param)
+				param = NULL;
+		}
+	}
 
 	trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
 
@@ -1081,14 +1100,10 @@
 			  struct event_trigger_data *data,
 			  struct trace_event_file *file)
 {
-	int ret = register_trigger(glob, ops, data, file);
+	if (tracing_alloc_snapshot_instance(file->tr) != 0)
+		return 0;
 
-	if (ret > 0 && tracing_alloc_snapshot_instance(file->tr) != 0) {
-		unregister_trigger(glob, ops, data, file);
-		ret = 0;
-	}
-
-	return ret;
+	return register_trigger(glob, ops, data, file);
 }
 
 static int
@@ -1365,6 +1380,11 @@
 	trigger = strsep(&param, " \t");
 	if (!trigger)
 		return -EINVAL;
+	if (param) {
+		param = skip_spaces(param);
+		if (!*param)
+			param = NULL;
+	}
 
 	system = strsep(&trigger, ":");
 	if (!trigger)
@@ -1497,7 +1517,9 @@
 	struct event_trigger_data *test;
 	int ret = 0;
 
-	list_for_each_entry_rcu(test, &file->triggers, list) {
+	lockdep_assert_held(&event_mutex);
+
+	list_for_each_entry(test, &file->triggers, list) {
 		test_enable_data = test->private_data;
 		if (test_enable_data &&
 		    (test->cmd_ops->trigger_type ==
@@ -1537,7 +1559,9 @@
 	struct event_trigger_data *data;
 	bool unregistered = false;
 
-	list_for_each_entry_rcu(data, &file->triggers, list) {
+	lockdep_assert_held(&event_mutex);
+
+	list_for_each_entry(data, &file->triggers, list) {
 		enable_data = data->private_data;
 		if (enable_data &&
 		    (data->cmd_ops->trigger_type ==