selftests/futex: Migrate functional tests to harness

Currently, multiple futex functional tests (wait_timeout, waitv,
wait_wouldblock) mix low-level ksft_* logging and result APIs with the
kselftest_harness.h framework. On older kernels where system calls like
futex_waitv are missing (returning -ENOSYS), this mixed usage triggers
framework inconsistencies, causing the test to fail with: "Illegal usage of
low-level ksft APIs in harness test".

Address this by completely refactoring these tests to exclusively use
the high-level kselftest_harness.h framework (gtest-like API), mapping
all low-level calls to native harness macros:

  - Non-fatal assertions: Replace ksft_test_result_fail() with EXPECT_EQ()
    and EXPECT_NE().

  - Fatal assertions: Replace ksft_exit_fail_msg() with ASSERT_EQ() and
    ASSERT_TRUE() to immediately terminate execution upon setup failure.

  - Test skipping: Replace ksft_exit_skip() with the graceful SKIP() macro
    combined with early runtime availability checks for sys_futex_waitv.

  - Debug logging: Replace ksft_print_dbg_msg() with TH_LOG() to inherit
    automatic file/line context.

  - Success reporting: Remove explicit ksft_test_result_pass() calls,
    deferring to automated harness completion reporting.

Additionally:

  - Fix a critical SIGSEGV crash in early syscall probing logic caused by
    passing a NULL pointer to inline user-space timespec conversions.

  - Introduce TEST_TIMEOUT() and GET_ABS_TIMEOUT() macros in wait_timeout
    to encapsulate assertions while preserving source line attribution.

  - Pass test metadata (_metadata) into secondary threads to allow native
    harness assertions during concurrent execution.

[ tglx: Fixup coding style ]

Signed-off-by: Wake Liu <wakel@google.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260526010635.23980-2-wakel@google.com

tools/testing/selftests/futex/functional/futex_wait_timeout.c

@@ -31,53 +31,47 @@ static pthread_barrier_t barrier;
  */
 void *get_pi_lock(void *arg)
 {
+	struct __test_metadata *_metadata = (struct __test_metadata *)arg;
 	int ret;
 	volatile futex_t lock = 0;
 
 	ret = futex_lock_pi(&futex_pi, NULL, 0, 0);
-	if (ret != 0)
-		ksft_exit_fail_msg("futex_lock_pi failed\n");
+	ASSERT_EQ(ret, 0)
+		TH_LOG("futex_lock_pi failed");
 
 	pthread_barrier_wait(&barrier);
 
 	/* Blocks forever */
 	ret = futex_wait(&lock, 0, NULL, 0);
-	ksft_exit_fail_msg("futex_wait failed\n");
+	ASSERT_TRUE(0)
+		TH_LOG("futex_wait returned unexpectedly: %d", ret);
 
 	return NULL;
 }
 
-/*
- * Check if the function returned the expected error
- */
-static void test_timeout(int res, char *test_name, int err)
-{
-	if (!res || errno != err) {
-		ksft_test_result_fail("%s returned %d\n", test_name,
-				      res < 0 ? errno : res);
-	} else {
-		ksft_test_result_pass("%s succeeds\n", test_name);
-	}
-}
+#define TEST_TIMEOUT(_res, _test_name, _err) do {				\
+	if ((_res) < 0 && errno == ENOSYS && (_err) != ENOSYS) {		\
+		SKIP(return, "%s is not supported (ENOSYS)", _test_name);	\
+	}									\
+	EXPECT_EQ((_res), -1)							\
+		TH_LOG("%s returned unexpected result: %d", _test_name, (_res));\
+	if ((_res) == -1) {							\
+		EXPECT_EQ(errno, (_err)) {					\
+			TH_LOG("%s returned unexpected errno: %d (expected %d)",\
+			       _test_name, errno, (_err));			\
+		}								\
+	}									\
+} while (0)
 
-/*
- * Calculate absolute timeout and correct overflow
- */
-static int futex_get_abs_timeout(clockid_t clockid, struct timespec *to,
-				 long timeout_ns)
-{
-	if (clock_gettime(clockid, to))
-		ksft_exit_fail_msg("clock_gettime failed\n");
-
-	to->tv_nsec += timeout_ns;
-
-	if (to->tv_nsec >= 1000000000) {
-		to->tv_sec++;
-		to->tv_nsec -= 1000000000;
-	}
-
-	return 0;
-}
+#define GET_ABS_TIMEOUT(_clockid, _to, _timeout_ns) do {		\
+	ASSERT_EQ(clock_gettime((_clockid), (_to)), 0)			\
+		TH_LOG("clock_gettime failed");				\
+	(_to)->tv_nsec += (_timeout_ns);				\
+	if ((_to)->tv_nsec >= 1000000000) {				\
+		(_to)->tv_sec++;					\
+		(_to)->tv_nsec -= 1000000000;				\
+	}								\
+} while (0)
 
 TEST(wait_bitset)
 {
@@ -90,19 +84,17 @@ TEST(wait_bitset)
 	to.tv_nsec = timeout_ns;
 
 	res = futex_wait(&f1, f1, &to, 0);
-	test_timeout(res, "futex_wait relative", ETIMEDOUT);
+	TEST_TIMEOUT(res, "futex_wait relative", ETIMEDOUT);
 
 	/* FUTEX_WAIT_BITSET with CLOCK_REALTIME */
-	if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
-		ksft_test_result_error("get_time error");
+	GET_ABS_TIMEOUT(CLOCK_REALTIME, &to, timeout_ns);
 	res = futex_wait_bitset(&f1, f1, &to, 1, FUTEX_CLOCK_REALTIME);
-	test_timeout(res, "futex_wait_bitset realtime", ETIMEDOUT);
+	TEST_TIMEOUT(res, "futex_wait_bitset realtime", ETIMEDOUT);
 
 	/* FUTEX_WAIT_BITSET with CLOCK_MONOTONIC */
-	if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
-		ksft_test_result_error("get_time error");
+	GET_ABS_TIMEOUT(CLOCK_MONOTONIC, &to, timeout_ns);
 	res = futex_wait_bitset(&f1, f1, &to, 1, 0);
-	test_timeout(res, "futex_wait_bitset monotonic", ETIMEDOUT);
+	TEST_TIMEOUT(res, "futex_wait_bitset monotonic", ETIMEDOUT);
 }
 
 TEST(requeue_pi)
@@ -112,17 +104,14 @@ TEST(requeue_pi)
 	int res;
 
 	/* FUTEX_WAIT_REQUEUE_PI with CLOCK_REALTIME */
-	if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
-		ksft_test_result_error("get_time error");
+	GET_ABS_TIMEOUT(CLOCK_REALTIME, &to, timeout_ns);
 	res = futex_wait_requeue_pi(&f1, f1, &futex_pi, &to, FUTEX_CLOCK_REALTIME);
-	test_timeout(res, "futex_wait_requeue_pi realtime", ETIMEDOUT);
+	TEST_TIMEOUT(res, "futex_wait_requeue_pi realtime", ETIMEDOUT);
 
 	/* FUTEX_WAIT_REQUEUE_PI with CLOCK_MONOTONIC */
-	if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
-		ksft_test_result_error("get_time error");
+	GET_ABS_TIMEOUT(CLOCK_MONOTONIC, &to, timeout_ns);
 	res = futex_wait_requeue_pi(&f1, f1, &futex_pi, &to, 0);
-	test_timeout(res, "futex_wait_requeue_pi monotonic", ETIMEDOUT);
-
+	TEST_TIMEOUT(res, "futex_wait_requeue_pi monotonic", ETIMEDOUT);
 }
 
 TEST(lock_pi)
@@ -133,7 +122,8 @@ TEST(lock_pi)
 
 	/* Create a thread that will lock forever so any waiter will timeout */
 	pthread_barrier_init(&barrier, NULL, 2);
-	pthread_create(&thread, NULL, get_pi_lock, NULL);
+	ASSERT_EQ(pthread_create(&thread, NULL, get_pi_lock, _metadata), 0)
+		TH_LOG("pthread_create failed");
 
 	/* Wait until the other thread calls futex_lock_pi() */
 	pthread_barrier_wait(&barrier);
@@ -149,14 +139,13 @@ TEST(lock_pi)
 	 * time or your time machine) the monotonic clock value is always
 	 * smaller than realtime and the syscall will timeout immediately.
 	 */
-	if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
-		ksft_test_result_error("get_time error");
+	GET_ABS_TIMEOUT(CLOCK_REALTIME, &to, timeout_ns);
 	res = futex_lock_pi(&futex_pi, &to, 0, 0);
-	test_timeout(res, "futex_lock_pi realtime", ETIMEDOUT);
+	TEST_TIMEOUT(res, "futex_lock_pi realtime", ETIMEDOUT);
 
 	/* Test operations that don't support FUTEX_CLOCK_REALTIME */
 	res = futex_lock_pi(&futex_pi, NULL, 0, FUTEX_CLOCK_REALTIME);
-	test_timeout(res, "futex_lock_pi invalid timeout flag", ENOSYS);
+	TEST_TIMEOUT(res, "futex_lock_pi invalid timeout flag", ENOSYS);
 }
 
 TEST(waitv)
@@ -171,17 +160,18 @@ TEST(waitv)
 	struct timespec to;
 	int res;
 
+	if (!is_futex_waitv_supported())
+		SKIP(return, "futex_waitv syscall not supported");
+
 	/* futex_waitv with CLOCK_MONOTONIC */
-	if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns))
-		ksft_test_result_error("get_time error");
+	GET_ABS_TIMEOUT(CLOCK_MONOTONIC, &to, timeout_ns);
 	res = futex_waitv(&waitv, 1, 0, &to, CLOCK_MONOTONIC);
-	test_timeout(res, "futex_waitv monotonic", ETIMEDOUT);
+	TEST_TIMEOUT(res, "futex_waitv monotonic", ETIMEDOUT);
 
 	/* futex_waitv with CLOCK_REALTIME */
-	if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns))
-		ksft_test_result_error("get_time error");
+	GET_ABS_TIMEOUT(CLOCK_REALTIME, &to, timeout_ns);
 	res = futex_waitv(&waitv, 1, 0, &to, CLOCK_REALTIME);
-	test_timeout(res, "futex_waitv realtime", ETIMEDOUT);
+	TEST_TIMEOUT(res, "futex_waitv realtime", ETIMEDOUT);
 }
 
 TEST_HARNESS_MAIN

tools/testing/selftests/futex/functional/futex_wait_wouldblock.c

@@ -28,20 +28,20 @@
 
 #define timeout_ns 100000
 
+
 TEST(futex_wait_wouldblock)
 {
 	struct timespec to = {.tv_sec = 0, .tv_nsec = timeout_ns};
 	futex_t f1 = FUTEX_INITIALIZER;
 	int res;
 
-	ksft_print_dbg_msg("Calling futex_wait on f1: %u @ %p with val=%u\n", f1, &f1, f1+1);
+	TH_LOG("Calling futex_wait on f1: %u @ %p with val=%u", f1, &f1, f1+1);
 	res = futex_wait(&f1, f1+1, &to, FUTEX_PRIVATE_FLAG);
-	if (!res || errno != EWOULDBLOCK) {
-		ksft_test_result_fail("futex_wait returned: %d %s\n",
-				      res ? errno : res,
-				      res ? strerror(errno) : "");
-	} else {
-		ksft_test_result_pass("futex_wait\n");
+	EXPECT_EQ(res, -1)
+		TH_LOG("futex_wait returned unexpected result: %d", res);
+	if (res == -1) {
+		EXPECT_EQ(errno, EWOULDBLOCK)
+			TH_LOG("futex_wait returned unexpected errno: %d", errno);
 	}
 }
 
@@ -57,8 +57,11 @@ TEST(futex_waitv_wouldblock)
 	};
 	int res;
 
-	if (clock_gettime(CLOCK_MONOTONIC, &to))
-		ksft_exit_fail_msg("clock_gettime failed %d\n", errno);
+	if (!is_futex_waitv_supported())
+		SKIP(return, "futex_waitv syscall not supported");
+
+	ASSERT_EQ(clock_gettime(CLOCK_MONOTONIC, &to), 0)
+		TH_LOG("clock_gettime failed");
 
 	to.tv_nsec += timeout_ns;
 
@@ -67,14 +70,13 @@ TEST(futex_waitv_wouldblock)
 		to.tv_nsec -= 1000000000;
 	}
 
-	ksft_print_dbg_msg("Calling futex_waitv on f1: %u @ %p with val=%u\n", f1, &f1, f1+1);
+	TH_LOG("Calling futex_waitv on f1: %u @ %p with val=%u", f1, &f1, f1+1);
 	res = futex_waitv(&waitv, 1, 0, &to, CLOCK_MONOTONIC);
-	if (!res || errno != EWOULDBLOCK) {
-		ksft_test_result_fail("futex_waitv returned: %d %s\n",
-				      res ? errno : res,
-				      res ? strerror(errno) : "");
-	} else {
-		ksft_test_result_pass("futex_waitv\n");
+	EXPECT_EQ(res, -1)
+		TH_LOG("futex_waitv returned unexpected result: %d", res);
+	if (res == -1) {
+		EXPECT_EQ(errno, EWOULDBLOCK)
+			TH_LOG("futex_waitv returned unexpected errno: %d", errno);
 	}
 }
 

tools/testing/selftests/futex/functional/futex_waitv.c

@@ -25,24 +25,26 @@
 static struct futex_waitv waitv[NR_FUTEXES];
 u_int32_t futexes[NR_FUTEXES] = {0};
 
+
 void *waiterfn(void *arg)
 {
+	struct __test_metadata *_metadata = (struct __test_metadata *)arg;
 	struct timespec to;
 	int res;
 
 	/* setting absolute timeout for futex2 */
-	if (clock_gettime(CLOCK_MONOTONIC, &to))
-		ksft_exit_fail_msg("gettime64 failed\n");
+	ASSERT_EQ(clock_gettime(CLOCK_MONOTONIC, &to), 0)
+		TH_LOG("gettime64 failed");
 
 	to.tv_sec++;
 
 	res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC);
 	if (res < 0) {
-		ksft_test_result_fail("futex_waitv returned: %d %s\n",
-				      errno, strerror(errno));
-	} else if (res != NR_FUTEXES - 1) {
-		ksft_test_result_fail("futex_waitv returned: %d, expecting %d\n",
-				      res, NR_FUTEXES - 1);
+		EXPECT_EQ(res, NR_FUTEXES - 1)
+			TH_LOG("futex_waitv failed: %s", strerror(errno));
+	} else {
+		EXPECT_EQ(res, NR_FUTEXES - 1)
+			TH_LOG("futex_waitv returned %d, expected %d", res, NR_FUTEXES - 1);
 	}
 
 	return NULL;
@@ -53,6 +55,9 @@ TEST(private_waitv)
 	pthread_t waiter;
 	int res, i;
 
+	if (!is_futex_waitv_supported())
+		SKIP(return, "futex_waitv syscall not supported");
+
 	for (i = 0; i < NR_FUTEXES; i++) {
 		waitv[i].uaddr = (uintptr_t)&futexes[i];
 		waitv[i].flags = FUTEX_32 | FUTEX_PRIVATE_FLAG;
@@ -61,19 +66,14 @@ TEST(private_waitv)
 	}
 
 	/* Private waitv */
-	if (pthread_create(&waiter, NULL, waiterfn, NULL))
-		ksft_exit_fail_msg("pthread_create failed\n");
+	ASSERT_EQ(pthread_create(&waiter, NULL, waiterfn, _metadata), 0)
+		TH_LOG("pthread_create failed");
 
 	usleep(WAKE_WAIT_US);
 
 	res = futex_wake(u64_to_ptr(waitv[NR_FUTEXES - 1].uaddr), 1, FUTEX_PRIVATE_FLAG);
-	if (res != 1) {
-		ksft_test_result_fail("futex_wake private returned: %d %s\n",
-				      res ? errno : res,
-				      res ? strerror(errno) : "");
-	} else {
-		ksft_test_result_pass("futex_waitv private\n");
-	}
+	EXPECT_EQ(res, 1)
+		TH_LOG("futex_wake private returned: %d %s", res, res < 0 ? strerror(errno) : "");
 }
 
 TEST(shared_waitv)
@@ -81,15 +81,18 @@ TEST(shared_waitv)
 	pthread_t waiter;
 	int res, i;
 
+	if (!is_futex_waitv_supported())
+		SKIP(return, "futex_waitv syscall not supported");
+
 	/* Shared waitv */
 	for (i = 0; i < NR_FUTEXES; i++) {
 		int shm_id = shmget(IPC_PRIVATE, 4096, IPC_CREAT | 0666);
 
 		if (shm_id < 0) {
 			if (errno == ENOSYS)
-				ksft_exit_skip("shmget syscall not supported\n");
-			perror("shmget");
-			exit(1);
+				SKIP(return, "shmget syscall not supported");
+			ASSERT_GE(shm_id, 0)
+				TH_LOG("shmget failed");
 		}
 
 		unsigned int *shared_data = shmat(shm_id, NULL, 0);
@@ -101,19 +104,14 @@ TEST(shared_waitv)
 		waitv[i].__reserved = 0;
 	}
 
-	if (pthread_create(&waiter, NULL, waiterfn, NULL))
-		ksft_exit_fail_msg("pthread_create failed\n");
+	ASSERT_EQ(pthread_create(&waiter, NULL, waiterfn, _metadata), 0)
+		TH_LOG("pthread_create failed");
 
 	usleep(WAKE_WAIT_US);
 
 	res = futex_wake(u64_to_ptr(waitv[NR_FUTEXES - 1].uaddr), 1, 0);
-	if (res != 1) {
-		ksft_test_result_fail("futex_wake shared returned: %d %s\n",
-				      res ? errno : res,
-				      res ? strerror(errno) : "");
-	} else {
-		ksft_test_result_pass("futex_waitv shared\n");
-	}
+	EXPECT_EQ(res, 1)
+		TH_LOG("futex_wake shared returned: %d %s", res, res < 0 ? strerror(errno) : "");
 
 	for (i = 0; i < NR_FUTEXES; i++)
 		shmdt(u64_to_ptr(waitv[i].uaddr));
@@ -124,21 +122,23 @@ TEST(invalid_flag)
 	struct timespec to;
 	int res;
 
+	if (!is_futex_waitv_supported())
+		SKIP(return, "futex_waitv syscall not supported");
+
 	/* Testing a waiter without FUTEX_32 flag */
 	waitv[0].flags = FUTEX_PRIVATE_FLAG;
 
-	if (clock_gettime(CLOCK_MONOTONIC, &to))
-		ksft_exit_fail_msg("gettime64 failed\n");
+	ASSERT_EQ(clock_gettime(CLOCK_MONOTONIC, &to), 0)
+		TH_LOG("gettime64 failed");
 
 	to.tv_sec++;
 
 	res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC);
 	if (res == EINVAL) {
-		ksft_test_result_fail("futex_waitv private returned: %d %s\n",
-				      res ? errno : res,
-				      res ? strerror(errno) : "");
-	} else {
-		ksft_test_result_pass("futex_waitv without FUTEX_32\n");
+		EXPECT_TRUE(0) {
+			TH_LOG("futex_waitv private returned: %d %s",
+			      res ? errno : res, res ? strerror(errno) : "");
+		}
 	}
 }
 
@@ -147,22 +147,24 @@ TEST(unaligned_address)
 	struct timespec to;
 	int res;
 
+	if (!is_futex_waitv_supported())
+		SKIP(return, "futex_waitv syscall not supported");
+
 	/* Testing a waiter with an unaligned address */
 	waitv[0].flags = FUTEX_PRIVATE_FLAG | FUTEX_32;
 	waitv[0].uaddr = 1;
 
-	if (clock_gettime(CLOCK_MONOTONIC, &to))
-		ksft_exit_fail_msg("gettime64 failed\n");
+	ASSERT_EQ(clock_gettime(CLOCK_MONOTONIC, &to), 0)
+		TH_LOG("gettime64 failed");
 
 	to.tv_sec++;
 
 	res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC);
 	if (res == EINVAL) {
-		ksft_test_result_fail("futex_wake private returned: %d %s\n",
-				      res ? errno : res,
-				      res ? strerror(errno) : "");
-	} else {
-		ksft_test_result_pass("futex_waitv with an unaligned address\n");
+		EXPECT_TRUE(0) {
+			TH_LOG("futex_wake private returned: %d %s",
+			       res ? errno : res, res ? strerror(errno) : "");
+		}
 	}
 }
 
@@ -171,36 +173,37 @@ TEST(null_address)
 	struct timespec to;
 	int res;
 
+	if (!is_futex_waitv_supported())
+		SKIP(return, "futex_waitv syscall not supported");
+
 	/* Testing a NULL address for waiters.uaddr */
 	waitv[0].uaddr = 0x00000000;
 
-	if (clock_gettime(CLOCK_MONOTONIC, &to))
-		ksft_exit_fail_msg("gettime64 failed\n");
+	ASSERT_EQ(clock_gettime(CLOCK_MONOTONIC, &to), 0)
+		TH_LOG("gettime64 failed");
 
 	to.tv_sec++;
 
 	res = futex_waitv(waitv, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC);
 	if (res == EINVAL) {
-		ksft_test_result_fail("futex_waitv private returned: %d %s\n",
-				      res ? errno : res,
-				      res ? strerror(errno) : "");
-	} else {
-		ksft_test_result_pass("futex_waitv NULL address in waitv.uaddr\n");
+		EXPECT_TRUE(0) {
+			TH_LOG("futex_waitv private returned: %d %s",
+			       res ? errno : res, res ? strerror(errno) : "");
+		}
 	}
 
 	/* Testing a NULL address for *waiters */
-	if (clock_gettime(CLOCK_MONOTONIC, &to))
-		ksft_exit_fail_msg("gettime64 failed\n");
+	ASSERT_EQ(clock_gettime(CLOCK_MONOTONIC, &to), 0)
+		TH_LOG("gettime64 failed");
 
 	to.tv_sec++;
 
 	res = futex_waitv(NULL, NR_FUTEXES, 0, &to, CLOCK_MONOTONIC);
 	if (res == EINVAL) {
-		ksft_test_result_fail("futex_waitv private returned: %d %s\n",
-				      res ? errno : res,
-				      res ? strerror(errno) : "");
-	} else {
-		ksft_test_result_pass("futex_waitv NULL address in *waiters\n");
+		EXPECT_TRUE(0) {
+			TH_LOG("futex_waitv private returned: %d %s",
+			       res ? errno : res, res ? strerror(errno) : "");
+		}
 	}
 }
 
@@ -209,19 +212,21 @@ TEST(invalid_clockid)
 	struct timespec to;
 	int res;
 
+	if (!is_futex_waitv_supported())
+		SKIP(return, "futex_waitv syscall not supported");
+
 	/* Testing an invalid clockid */
-	if (clock_gettime(CLOCK_MONOTONIC, &to))
-		ksft_exit_fail_msg("gettime64 failed\n");
+	ASSERT_EQ(clock_gettime(CLOCK_MONOTONIC, &to), 0)
+		TH_LOG("gettime64 failed");
 
 	to.tv_sec++;
 
 	res = futex_waitv(NULL, NR_FUTEXES, 0, &to, CLOCK_TAI);
 	if (res == EINVAL) {
-		ksft_test_result_fail("futex_waitv private returned: %d %s\n",
-				      res ? errno : res,
-				      res ? strerror(errno) : "");
-	} else {
-		ksft_test_result_pass("futex_waitv invalid clockid\n");
+		EXPECT_TRUE(0) {
+			TH_LOG("futex_waitv private returned: %d %s",
+				      res ? errno : res, res ? strerror(errno) : "");
+		}
 	}
 }
 

tools/testing/selftests/futex/include/futex2test.h

@@ -5,7 +5,9 @@
  * Copyright 2021 Collabora Ltd.
  */
 #include <linux/time_types.h>
+#include <errno.h>
 #include <stdint.h>
+#include <stdbool.h>
 
 #define u64_to_ptr(x) ((void *)(uintptr_t)(x))
 
@@ -96,3 +98,11 @@ static inline int futex2_wake(void *uaddr, int nr, unsigned int flags)
 {
 	return syscall(__NR_futex_wake, uaddr, ~0U, nr, flags);
 }
+
+static inline bool is_futex_waitv_supported(void)
+{
+	struct timespec ts = {0, 0};
+	int res = futex_waitv(NULL, 0, 0, &ts, CLOCK_MONOTONIC);
+
+	return !(res < 0 && errno == ENOSYS);
+}