From 3c89b58fdec8dde5c2135116169a2eb7f4e8d474 Mon Sep 17 00:00:00 2001
From: jiangjianfeng <jiangjianfeng.jjf@antgroup.com>
Date: Thu, 13 Nov 2025 11:43:07 +0000
Subject: [PATCH] Add regression test for open ptmx

---
 test/src/apps/pty/open_ptmx.c    | 97 ++++++++++++++++++++++++++++++++
 test/src/apps/scripts/process.sh |  1 +
 2 files changed, 98 insertions(+)
 create mode 100644 test/src/apps/pty/open_ptmx.c

diff --git a/test/src/apps/pty/open_ptmx.c b/test/src/apps/pty/open_ptmx.c
new file mode 100644
index 000000000..5bf620ae6
--- /dev/null
+++ b/test/src/apps/pty/open_ptmx.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: MPL-2.0
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <termios.h>
+#include <pty.h>
+#include <poll.h>
+#include <sys/wait.h>
+#include "../test.h"
+
+#define DEV_PTMX "/dev/ptmx"
+
+int master;
+int slave;
+char slave_name[128];
+
+FN_SETUP(open_ptmx)
+{
+	master = CHECK(open(DEV_PTMX, O_RDWR));
+	int slave_index;
+	CHECK(ioctl(master, TIOCGPTN, &slave_index));
+	memset(slave_name, 0, sizeof(slave_name));
+	sprintf(slave_name, "/dev/pts/%d", slave_index);
+}
+END_SETUP()
+
+FN_TEST(read_write_before_open_slave)
+{
+	// Set master nonblocking mode
+	int flags = TEST_SUCC(fcntl(master, F_GETFL, 0));
+	TEST_SUCC(fcntl(master, F_SETFL, flags | O_NONBLOCK));
+
+	char buf[1] = { 'a' };
+	TEST_ERRNO(read(master, buf, sizeof(buf)), EAGAIN);
+	TEST_SUCC(write(master, buf, 1));
+}
+END_TEST()
+
+FN_TEST(clear_lock_and_open_slave)
+{
+	TEST_ERRNO(open(slave_name, O_RDWR), EIO);
+	TEST_ERRNO(ioctl(master, TIOCGPTPEER, NULL), EIO);
+
+	// Unlock pty lock
+	int lock;
+	TEST_RES(ioctl(master, TIOCGPTLCK, &lock), lock == 1);
+	lock = 0;
+	TEST_SUCC(ioctl(master, TIOCSPTLCK, &lock));
+	TEST_RES(ioctl(master, TIOCGPTLCK, &lock), lock == 0);
+
+	slave = TEST_SUCC(open(slave_name, O_RDWR));
+	int tmp_sfd = TEST_SUCC(ioctl(master, TIOCGPTPEER, NULL));
+	TEST_SUCC(close(tmp_sfd));
+}
+END_TEST()
+
+FN_TEST(read_write)
+{
+	// Set master blocking mode
+	int flags = TEST_SUCC(fcntl(master, F_GETFL, 0));
+	TEST_SUCC(fcntl(master, F_SETFL, flags & (~O_NONBLOCK)));
+
+	pid_t pid = TEST_SUCC(fork());
+	if (pid == 0) {
+		char buf[1] = { 0 };
+		CHECK_WITH(read(master, buf, sizeof(buf)),
+			   _ret == 1 && buf[0] == 'a');
+		exit(EXIT_SUCCESS);
+	}
+
+	// Set slave raw mode
+	struct termios term;
+	TEST_SUCC(tcgetattr(slave, &term));
+	term.c_lflag &= ~(ICANON | ECHO);
+	term.c_cc[VMIN] = 1;
+	term.c_cc[VTIME] = 0;
+	TEST_SUCC(tcsetattr(slave, TCSANOW, &term));
+
+	// Read the byte master has written.
+	char buf[1] = { 0 };
+	TEST_RES(read(slave, buf, sizeof(buf)), _ret == 1 && buf[0] == 'a');
+
+	TEST_SUCC(write(slave, buf, sizeof(buf)));
+
+	TEST_SUCC(wait(NULL));
+}
+END_TEST()
+
+FN_SETUP(cleanup)
+{
+	CHECK(close(master));
+	CHECK(close(slave));
+}
+END_SETUP()
diff --git a/test/src/apps/scripts/process.sh b/test/src/apps/scripts/process.sh
index 6f387824f..62aaf10cd 100755
--- a/test/src/apps/scripts/process.sh
+++ b/test/src/apps/scripts/process.sh
@@ -48,6 +48,7 @@ pseudofs/pseudo_inode
 pseudofs/memfd_access_err
 pthread/pthread_test
 pty/close_pty
+pty/open_ptmx
 pty/open_pty
 pty/pty_blocking
 sched/sched_attr_getset