kpatch/test/integration/rhel-7.6/new-function.patch

Index: kernel-rhel7/drivers/tty/n_tty.c
===================================================================
--- kernel-rhel7.orig/drivers/tty/n_tty.c
+++ kernel-rhel7/drivers/tty/n_tty.c
@@ -2128,7 +2128,7 @@ do_it_again:
  *		  lock themselves)
  */
 
-static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
+static ssize_t noinline kpatch_n_tty_write(struct tty_struct *tty, struct file *file,
 			   const unsigned char *buf, size_t nr)
 {
 	const unsigned char *b = buf;
@@ -2210,6 +2210,12 @@ break_out:
 	return (b - buf) ? b - buf : retval;
 }
 
+static ssize_t __attribute__((optimize("-fno-optimize-sibling-calls"))) n_tty_write(struct tty_struct *tty, struct file *file,
+			   const unsigned char *buf, size_t nr)
+{
+	return kpatch_n_tty_write(tty, file, buf, nr);
+}
+
 /**
  *	n_tty_poll		-	poll method for N_TTY
  *	@tty: terminal device