[LTP] [PATCH 2/4] futex_wait07: Add EINTR error coverage test

[Michael Menasherov]

---
 runtest/syscalls                              |  1 +
 testcases/kernel/syscalls/futex/.gitignore    |  1 +
 .../kernel/syscalls/futex/futex_wait07.c      | 91 +++++++++++++++++++
 3 files changed, 93 insertions(+)
 create mode 100644 testcases/kernel/syscalls/futex/futex_wait07.c

diff --git a/runtest/syscalls b/runtest/syscalls
index 621355e04..75b7754db 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1906,3 +1906,4 @@ io_uring03 io_uring03
 # Tests below may cause kernel memory leak
 perf_event_open03 perf_event_open03
 futex_wait06 futex_wait06
+futex_wait07 futex_wait07
diff --git a/testcases/kernel/syscalls/futex/.gitignore b/testcases/kernel/syscalls/futex/.gitignore
index 56596dcb4..74ac9a926 100644
--- a/testcases/kernel/syscalls/futex/.gitignore
+++ b/testcases/kernel/syscalls/futex/.gitignore
@@ -14,3 +14,4 @@
 /futex_waitv02
 /futex_waitv03
 /futex_wait06
+/futex_wait07
diff --git a/testcases/kernel/syscalls/futex/futex_wait07.c b/testcases/kernel/syscalls/futex/futex_wait07.c
new file mode 100644
index 000000000..c3063389a
--- /dev/null
+++ b/testcases/kernel/syscalls/futex/futex_wait07.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2026 Red Hat, Inc.
+ */
+
+/*\
+ * Check that futex(FUTEX_WAIT) returns EINTR when interrupted by a signal.
+ * A child process blocks on futex_wait() with a long timeout. The parent
+ * waits for the child to enter sleep state, then sends SIGUSR1 to it.
+ * The child verifies it received EINTR and exits accordingly.
+ */
+
+#include <errno.h>
+#include <signal.h>
+
+#include "futextest.h"
+
+static futex_t *futex;
+
+static struct futex_test_variants variants[] = {
+#if (__NR_futex != __LTP__NR_INVALID_SYSCALL)
+	{ .fntype = FUTEX_FN_FUTEX, .tstype = TST_KERN_OLD_TIMESPEC, .desc = "syscall with old kernel spec"},
+#endif
+
+#if (__NR_futex_time64 != __LTP__NR_INVALID_SYSCALL)
+	{ .fntype = FUTEX_FN_FUTEX64, .tstype = TST_KERN_TIMESPEC, .desc = "syscall time64 with kernel spec"},
+#endif
+};
+
+/* We need a handler so SIGUSR1 is caught instead of killing the process.
+ * The empty body is needed, just receiving the signal is enough to
+ * interrupt futex_wait() and make it return into EINTR -1 status.
+ */
+static void sigusr1_handler(int sig LTP_ATTRIBUTE_UNUSED)
+{
+}
+
+static void do_child(void)
+{
+	struct futex_test_variants *tv = &variants[tst_variant];
+	struct sigaction sa;
+	struct tst_ts timeout;
+
+	sa.sa_handler = sigusr1_handler;
+	sa.sa_flags = 0;
+	SAFE_SIGEMPTYSET(&sa.sa_mask);
+	SAFE_SIGACTION(SIGUSR1, &sa, NULL);
+
+	timeout = tst_ts_from_ms(tv->tstype, 5000);
+	TST_EXP_FAIL(futex_wait(tv->fntype, futex, *futex, &timeout, 0), EINTR);
+	exit(0);
+}
+
+static void run(void)
+{
+	pid_t child;
+
+	child = SAFE_FORK();
+
+	if (child == 0)
+		do_child();
+
+	TST_PROCESS_STATE_WAIT(child, 'S', 0);
+	SAFE_KILL(child, SIGUSR1);
+}
+
+static void setup(void)
+{
+	struct futex_test_variants *tv = &variants[tst_variant];
+
+	tst_res(TINFO, "Testing variant: %s", tv->desc);
+	futex_supported_by_kernel(tv->fntype);
+
+	futex = SAFE_MMAP(NULL, sizeof(*futex), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0);
+	*futex = FUTEX_INITIALIZER;
+}
+
+static void cleanup(void)
+{
+	if (futex) {
+		SAFE_MUNMAP((void *)futex, sizeof(*futex));
+	}
+}
+
+static struct tst_test test = {
+	.setup = setup,
+	.cleanup = cleanup,
+	.test_all = run,
+	.test_variants = ARRAY_SIZE(variants),
+	.forks_child = 1,
+};
-- 
2.53.0