Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index b0875b3..d4e31e9 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -6,6 +6,7 @@
  *
  */
 #include <linux/seq_file.h>
+#include <linux/security.h>
 #include <linux/uaccess.h>
 #include <linux/kernel.h>
 #include <linux/ftrace.h>
@@ -115,7 +116,7 @@
  * section, then we need to read the link list pointers. The trick is
  * we pass the address of the string to the seq function just like
  * we do for the kernel core formats. To get back the structure that
- * holds the format, we simply use containerof() and then go to the
+ * holds the format, we simply use container_of() and then go to the
  * next format in the list.
  */
 static const char **
@@ -348,6 +349,12 @@
 static int
 ftrace_formats_open(struct inode *inode, struct file *file)
 {
+	int ret;
+
+	ret = security_locked_down(LOCKDOWN_TRACEFS);
+	if (ret)
+		return ret;
+
 	return seq_open(file, &show_format_seq_ops);
 }