Add pty08 test

Verify that slave pseudo-terminal fails reading/writing if master has
been closed.

Reviewed-by: Cyril Hrubis <[email protected]>
Signed-off-by: Andrea Cervesato <[email protected]>

runtest/pty

@@ -6,6 +6,7 @@ pty04 pty04
 pty05 pty05
 pty06 pty06
 pty07 pty07
+pty08 pty08
 ptem01 ptem01
 ptem02 ptem02
 ptem03 ptem03

testcases/kernel/pty/.gitignore

@@ -12,3 +12,4 @@
 /pty05
 /pty06
 /pty07
+/pty08

testcases/kernel/pty/pty08.c

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) International Business Machines  Corp., 2002
+ * Copyright (C) 2024 SUSE LLC Andrea Cervesato <[email protected]>
+ */
+
+/*\
+ * [Description]
+ *
+ * Verify that slave pseudo-terminal fails reading/writing if master has been
+ * closed.
+ */
+
+#define _GNU_SOURCE
+
+#include "common.h"
+
+static void run(void)
+{
+	int slavefd;
+	int masterfd;
+	char buf;
+
+	masterfd = open_master();
+	slavefd = open_slave(masterfd);
+
+	tst_res(TINFO, "Closing master communication");
+	SAFE_CLOSE(masterfd);
+
+	TST_EXP_EQ_LI(read(slavefd, &buf, 1), 0);
+	TST_EXP_FAIL(write(slavefd, &buf, 1), EIO);
+
+	SAFE_CLOSE(slavefd);
+}
+
+static struct tst_test test = {
+	.test_all = run,
+};