[PATCH v2 1/2] selftests/futex: Migrate functional tests to harness
From: Wake Liu
Date: Mon May 25 2026 - 21:07:16 EST
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.
Signed-off-by: Wake Liu <wakel@xxxxxxxxxx>
---
.../futex/functional/futex_wait_timeout.c | 104 ++++++++----------
.../futex/functional/futex_wait_wouldblock.c | 33 +++---
.../selftests/futex/functional/futex_waitv.c | 100 ++++++++---------
.../selftests/futex/include/futex2test.h | 10 ++
4 files changed, 117 insertions(+), 130 deletions(-)
diff --git a/tools/testing/selftests/futex/functional/futex_wait_timeout.c b/tools/testing/selftests/futex/functional/futex_wait_timeout.c
index 674dd13af421..a79ec51d0f34 100644
--- a/tools/testing/selftests/futex/functional/futex_wait_timeout.c
+++ b/tools/testing/selftests/futex/functional/futex_wait_timeout.c
@@ -31,53 +31,43 @@ 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);
- }
-}
-
-/*
- * 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 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)
+
+#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 +80,17 @@ 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 +100,14 @@ 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 +118,8 @@ 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 +135,13 @@ 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 +156,18 @@ 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
diff --git a/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c b/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
index 9ff936ecf164..5683569e83d9 100644
--- a/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
+++ b/tools/testing/selftests/futex/functional/futex_wait_wouldblock.c
@@ -28,21 +28,19 @@
#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);
}
TEST(futex_waitv_wouldblock)
@@ -57,8 +55,10 @@ 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;
@@ -67,15 +67,12 @@ 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);
}
TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/futex/functional/futex_waitv.c b/tools/testing/selftests/futex/functional/futex_waitv.c
index b5ada9fdb26f..3053f69cf0c3 100644
--- a/tools/testing/selftests/futex/functional/futex_waitv.c
+++ b/tools/testing/selftests/futex/functional/futex_waitv.c
@@ -25,24 +25,24 @@
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 +53,9 @@ 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 +64,15 @@ 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 +80,17 @@ 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 +102,15 @@ 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 +121,21 @@ 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",
+ EXPECT_TRUE(0) TH_LOG("futex_waitv private returned: %d %s",
res ? errno : res,
res ? strerror(errno) : "");
- } else {
- ksft_test_result_pass("futex_waitv without FUTEX_32\n");
}
}
@@ -147,22 +144,22 @@ 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",
+ EXPECT_TRUE(0) TH_LOG("futex_wake private returned: %d %s",
res ? errno : res,
res ? strerror(errno) : "");
- } else {
- ksft_test_result_pass("futex_waitv with an unaligned address\n");
}
}
@@ -171,36 +168,33 @@ 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",
+ EXPECT_TRUE(0) TH_LOG("futex_waitv private returned: %d %s",
res ? errno : res,
res ? strerror(errno) : "");
- } else {
- ksft_test_result_pass("futex_waitv NULL address in waitv.uaddr\n");
}
/* 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",
+ EXPECT_TRUE(0) TH_LOG("futex_waitv private returned: %d %s",
res ? errno : res,
res ? strerror(errno) : "");
- } else {
- ksft_test_result_pass("futex_waitv NULL address in *waiters\n");
}
}
@@ -209,19 +203,19 @@ 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",
+ EXPECT_TRUE(0) TH_LOG("futex_waitv private returned: %d %s",
res ? errno : res,
res ? strerror(errno) : "");
- } else {
- ksft_test_result_pass("futex_waitv invalid clockid\n");
}
}
diff --git a/tools/testing/selftests/futex/include/futex2test.h b/tools/testing/selftests/futex/include/futex2test.h
index 1f625b39948a..d157ba45eabc 100644
--- a/tools/testing/selftests/futex/include/futex2test.h
+++ b/tools/testing/selftests/futex/include/futex2test.h
@@ -6,6 +6,8 @@
*/
#include <linux/time_types.h>
#include <stdint.h>
+#include <stdbool.h>
+#include <errno.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);
+}
--
2.54.0.746.g67dd491aae-goog