[LTP] [PATCH v4] Add epoll_wait07 test

[Andrea Cervesato]

From: Andrea Cervesato <andrea.cervesato@suse.com>

This test verifies that EPOLLONESHOT is correctly handled by
epoll_wait.

Implements: https://github.com/linux-test-project/ltp/issues/860
Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
 runtest/syscalls                              |  1 +
 .../kernel/syscalls/epoll_wait/.gitignore     |  1 +
 .../kernel/syscalls/epoll_wait/epoll_wait07.c | 73 +++++++++++++++++++
 3 files changed, 75 insertions(+)
 create mode 100644 testcases/kernel/syscalls/epoll_wait/epoll_wait07.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 88e868a74..1cdba11ce 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -175,6 +175,7 @@ epoll_wait01 epoll_wait01
 epoll_wait02 epoll_wait02
 epoll_wait03 epoll_wait03
 epoll_wait04 epoll_wait04
+epoll_wait07 epoll_wait07
 epoll_pwait01 epoll_pwait01
 epoll_pwait02 epoll_pwait02
 epoll_pwait03 epoll_pwait03
diff --git a/testcases/kernel/syscalls/epoll_wait/.gitignore b/testcases/kernel/syscalls/epoll_wait/.gitignore
index 222955dd2..c0be9a88e 100644
--- a/testcases/kernel/syscalls/epoll_wait/.gitignore
+++ b/testcases/kernel/syscalls/epoll_wait/.gitignore
@@ -2,3 +2,4 @@ epoll_wait01
 epoll_wait02
 epoll_wait03
 epoll_wait04
+epoll_wait07
diff --git a/testcases/kernel/syscalls/epoll_wait/epoll_wait07.c b/testcases/kernel/syscalls/epoll_wait/epoll_wait07.c
new file mode 100644
index 000000000..dfabd0d87
--- /dev/null
+++ b/testcases/kernel/syscalls/epoll_wait/epoll_wait07.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2023 SUSE LLC Andrea Cervesato <andrea.cervesato@suse.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * Verify that EPOLLONESHOT is correctly handled by epoll_wait.
+ * We open a channel, write in it two times and verify that EPOLLIN has been
+ * received only once.
+ */
+
+#include <poll.h>
+#include <sys/epoll.h>
+#include "tst_test.h"
+#include "tst_epoll.h"
+
+static int fds[2];
+static int epfd;
+
+static void cleanup(void)
+{
+	if (epfd > 0)
+		SAFE_CLOSE(epfd);
+
+	if (fds[0] > 0)
+		SAFE_CLOSE(fds[0]);
+
+	if (fds[1] > 0)
+		SAFE_CLOSE(fds[1]);
+}
+
+static void run(void)
+{
+	struct epoll_event evt_receive;
+	char buff = 'a';
+
+	SAFE_PIPE(fds);
+
+	tst_res(TINFO, "Polling on channel with EPOLLONESHOT");
+
+	epfd = SAFE_EPOLL_CREATE1(0);
+
+	SAFE_EPOLL_CTL(epfd, EPOLL_CTL_ADD, fds[0], &((struct epoll_event) {
+		.events = EPOLLIN | EPOLLONESHOT,
+		.data.fd = fds[0],
+	}));
+
+	tst_res(TINFO, "Write channel for the 1st time. EPOLLIN expected");
+
+	SAFE_WRITE(0, fds[1], &buff, 1);
+	TST_EXP_EQ_LI(SAFE_EPOLL_WAIT(epfd, &evt_receive, 10, 0), 1);
+	TST_EXP_EQ_LI(evt_receive.events & EPOLLIN, EPOLLIN);
+	TST_EXP_EQ_LI(evt_receive.data.fd, fds[0]);
+
+	SAFE_READ(1, fds[0], &buff, 1);
+	TST_EXP_EQ_LI(SAFE_EPOLL_WAIT(epfd, &evt_receive, 10, 0), 0);
+
+	tst_res(TINFO, "Write channel for the 2nd time. No events expected");
+
+	SAFE_WRITE(0, fds[1], &buff, 1);
+	TST_EXP_EQ_LI(SAFE_EPOLL_WAIT(epfd, &evt_receive, 10, 0), 0);
+
+	SAFE_CLOSE(epfd);
+	SAFE_CLOSE(fds[0]);
+	SAFE_CLOSE(fds[1]);
+}
+
+static struct tst_test test = {
+	.cleanup = cleanup,
+	.test_all = run,
+};
-- 
2.35.3