[LTP] [PATCH] flock: Add negative tests for flock

[Yang Xu]

Add negative cases for flock(), when errno is EINTR or EWOULDBLOCK

Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
---
 runtest/syscalls                           |  1 +
 testcases/kernel/syscalls/flock/.gitignore |  1 +
 testcases/kernel/syscalls/flock/flock07.c  | 98 ++++++++++++++++++++++
 3 files changed, 100 insertions(+)
 create mode 100644 testcases/kernel/syscalls/flock/flock07.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 9578e991a..de4f5a633 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -375,6 +375,7 @@ flock02 flock02
 flock03 flock03
 flock04 flock04
 flock06 flock06
+flock07 flock07
 
 fmtmsg01 fmtmsg01
 
diff --git a/testcases/kernel/syscalls/flock/.gitignore b/testcases/kernel/syscalls/flock/.gitignore
index c8cb0fc54..9bac582e1 100644
--- a/testcases/kernel/syscalls/flock/.gitignore
+++ b/testcases/kernel/syscalls/flock/.gitignore
@@ -3,3 +3,4 @@
 /flock03
 /flock04
 /flock06
+/flock07
diff --git a/testcases/kernel/syscalls/flock/flock07.c b/testcases/kernel/syscalls/flock/flock07.c
new file mode 100644
index 000000000..6fd650186
--- /dev/null
+++ b/testcases/kernel/syscalls/flock/flock07.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2024 FUJITSU LIMITED. All Rights Reserved.
+ * Author: Yang Xu <xuyang2018.jy@fujitsu.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * Verify that flock(2) fails with
+ *
+ * - EINTR when waiting lock, call is interrupted by signal
+ * - EWOULDBLOCK when file is locked and LOCK_NB flag is selected
+ */
+
+#include <signal.h>
+#include <sys/file.h>
+#include <sys/wait.h>
+#include "tst_test.h"
+
+#define TEST_INTR "test_intr"
+#define TEST_EWOULDBLOCK "test_ewouldblock"
+
+static struct test_case_t {
+	char *filename;
+	int expected_errno;
+	int child;
+	char *desc;
+} tcases[] = {
+	{TEST_INTR, EINTR, 1,
+		"while waiting lock, call is interrupted by signal"},
+	{TEST_EWOULDBLOCK, EWOULDBLOCK, 0,
+		"file is locked and LOCK_NB flag is selected"},
+};
+
+static void setup(void)
+{
+	SAFE_TOUCH(TEST_INTR, 0777, NULL);
+	SAFE_TOUCH(TEST_EWOULDBLOCK, 0777, NULL);
+}
+
+static void handler(int sig)
+{
+	switch (sig) {
+	case SIGUSR1:
+		tst_res(TINFO, "%s", "Got SIGUSR1");
+	break;
+	default:
+		tst_res(TINFO, "%s", "Got other signal");
+	break;
+	}
+}
+
+static void child_do(int fd, struct test_case_t *tc)
+{
+	struct sigaction sa;
+
+	sa.sa_handler = handler;
+	SAFE_SIGEMPTYSET(&sa.sa_mask);
+	SAFE_SIGACTION(SIGUSR1, &sa, NULL);
+
+	TST_EXP_FAIL(flock(fd, LOCK_EX), tc->expected_errno, "%s", tc->desc);
+}
+
+static void verify_flock(unsigned int i)
+{
+	struct test_case_t *tc = &tcases[i];
+	pid_t pid;
+	int fd1 = SAFE_OPEN(tc->filename, O_RDWR);
+	int fd2 = SAFE_OPEN(tc->filename, O_RDWR);
+
+	if (tc->child) {
+		flock(fd1, LOCK_EX);
+		pid = SAFE_FORK();
+		if (!pid) {
+			child_do(fd2, tc);
+			exit(0);
+		}
+		sleep(1);
+		SAFE_KILL(pid, SIGUSR1);
+		SAFE_WAITPID(pid, NULL, 0);
+	} else {
+		flock(fd1, LOCK_EX);
+		TST_EXP_FAIL(flock(fd2, LOCK_EX | LOCK_NB), tc->expected_errno,
+			"%s", tc->desc);
+	}
+	SAFE_CLOSE(fd1);
+	SAFE_CLOSE(fd2);
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.tcnt = ARRAY_SIZE(tcases),
+	.test = verify_flock,
+	.needs_tmpdir = 1,
+	.needs_root = 1,
+	.forks_child = 1,
+};
-- 
2.39.3