--- zzzz-none-000/linux-4.9.279/mm/util.c	2021-08-08 06:38:54.000000000 +0000
+++ puma7-atom-6591-750/linux-4.9.279/mm/util.c	2023-02-08 11:43:43.000000000 +0000
@@ -675,3 +675,62 @@
 out:
 	return res;
 }
+
+static void show_task_cmdline(struct task_struct *task)
+{
+	char comm[TASK_COMM_LEN];
+	char cmdline[0x7f];
+	char *arg;
+	int argsiz;
+
+	get_task_comm(comm, task);
+	argsiz = get_cmdline(task, cmdline, sizeof(cmdline));
+	if (argsiz < 0) {
+		pr_err("Error reading cmdline of task %d: %d\n",
+		       task_pid_nr(task), argsiz);
+		return;
+	}
+
+	/* Strip a terminating NUL, if present */
+	if (argsiz && argsiz < sizeof(cmdline) && cmdline[argsiz] == '\0')
+		--argsiz;
+
+	/* Replace embedded NUL chars */
+	arg = cmdline;
+	while ((arg = memchr(arg, '\0', cmdline + argsiz - arg)))
+		*arg = ' ';
+
+	pr_notice("  comm=%s[%d], cmdline: %.*s\n",
+		comm, task_pid_nr(task), argsiz, cmdline);
+}
+
+static struct task_struct *get_task_parent(struct task_struct *task)
+{
+	struct task_struct *parent;
+
+	rcu_read_lock();
+	parent = rcu_dereference(task->real_parent);
+	if (parent)
+		get_task_struct(parent);
+	rcu_read_unlock();
+
+	return parent;
+}
+
+void show_parent_tasks_cmdlines(struct task_struct *task)
+{
+	pr_notice("Parent process chain of PID %d:\n", task_pid_nr(task));
+
+	get_task_struct(task);
+	while (task && !is_global_init(task)) {
+		struct task_struct *parent;
+
+		show_task_cmdline(task);
+
+		parent = get_task_parent(task);
+		put_task_struct(task);
+		task = parent;
+	}
+	if (task)
+		put_task_struct(task);
+}