linux: Improve debugging by recognizing TIOCGPTPEER

Sponsored By:	EPSRC

sys/compat/linux/linux_ioctl.c

@@ -1020,6 +1020,10 @@ linux_ioctl_termio(struct thread *td, struct linux_ioctl_args *args)
 			    sizeof(int));
 		break;
 	}
+	case LINUX_TIOCGPTPEER:
+		linux_msg(td, "unsupported ioctl TIOCGPTPEER");
+		error = ENOIOCTL;
+		break;
 	case LINUX_TIOCSPTLCK:
 		/* Our unlockpt() does nothing. */
 		error = 0;

sys/compat/linux/linux_ioctl.h

@@ -386,6 +386,8 @@
 #define LINUX_TIOCGPTN		0x5430
 #define LINUX_TIOCSPTLCK	0x5431
 
+#define	LINUX_TIOCGPTPEER	0x5441
+
 #define	LINUX_FIONCLEX		0x5450
 #define	LINUX_FIOCLEX		0x5451
 #define	LINUX_FIOASYNC		0x5452