tools/nolibc: add support for clock_nanosleep() and nanosleep()

Also add some tests.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250704-nolibc-nanosleep-v1-1-d79c19701952@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

Author: t-8ch

tools/include/nolibc/time.h

@@ -36,6 +36,8 @@ void __nolibc_timespec_kernel_to_user(const struct __kernel_timespec *kts, struc
  * int clock_getres(clockid_t clockid, struct timespec *res);
  * int clock_gettime(clockid_t clockid, struct timespec *tp);
  * int clock_settime(clockid_t clockid, const struct timespec *tp);
+ * int clock_nanosleep(clockid_t clockid, int flags, const struct timespec *rqtp,
+ *                     struct timespec *rmtp)
  */
 
 static __attribute__((unused))
@@ -107,13 +109,45 @@ int clock_settime(clockid_t clockid, struct timespec *tp)
 	return __sysret(sys_clock_settime(clockid, tp));
 }
 
+static __attribute__((unused))
+int sys_clock_nanosleep(clockid_t clockid, int flags, const struct timespec *rqtp,
+			struct timespec *rmtp)
+{
+#if defined(__NR_clock_nanosleep)
+	return my_syscall4(__NR_clock_nanosleep, clockid, flags, rqtp, rmtp);
+#elif defined(__NR_clock_nanosleep_time64)
+	struct __kernel_timespec krqtp, krmtp;
+	int ret;
+
+	__nolibc_timespec_user_to_kernel(rqtp, &krqtp);
+	ret = my_syscall4(__NR_clock_nanosleep_time64, clockid, flags, &krqtp, &krmtp);
+	if (rmtp)
+		__nolibc_timespec_kernel_to_user(&krmtp, rmtp);
+	return ret;
+#else
+	return __nolibc_enosys(__func__, clockid, flags, rqtp, rmtp);
+#endif
+}
+
+static __attribute__((unused))
+int clock_nanosleep(clockid_t clockid, int flags, const struct timespec *rqtp,
+		    struct timespec *rmtp)
+{
+	return __sysret(sys_clock_nanosleep(clockid, flags, rqtp, rmtp));
+}
 
 static __inline__
 double difftime(time_t time1, time_t time2)
 {
 	return time1 - time2;
 }
 
+static __inline__
+int nanosleep(const struct timespec *rqtp, struct timespec *rmtp)
+{
+	return clock_nanosleep(CLOCK_REALTIME, 0, rqtp, rmtp);
+}
+
 
 static __attribute__((unused))
 time_t time(time_t *tptr)

tools/testing/selftests/nolibc/nolibc-test.c

@@ -1363,6 +1363,7 @@ int run_syscall(int min, int max)
 		CASE_TEST(mmap_bad);          EXPECT_PTRER(1, mmap(NULL, 0, PROT_READ, MAP_PRIVATE, 0, 0), MAP_FAILED, EINVAL); break;
 		CASE_TEST(munmap_bad);        EXPECT_SYSER(1, munmap(NULL, 0), -1, EINVAL); break;
 		CASE_TEST(mmap_munmap_good);  EXPECT_SYSZR(1, test_mmap_munmap()); break;
+		CASE_TEST(nanosleep);         ts.tv_nsec = -1; EXPECT_SYSER(1, nanosleep(&ts, NULL), -1, EINVAL); break;
 		CASE_TEST(open_tty);          EXPECT_SYSNE(1, tmp = open("/dev/null", O_RDONLY), -1); if (tmp != -1) close(tmp); break;
 		CASE_TEST(open_blah);         EXPECT_SYSER(1, tmp = open("/proc/self/blah", O_RDONLY), -1, ENOENT); if (tmp != -1) close(tmp); break;
 		CASE_TEST(openat_dir);        EXPECT_SYSZR(1, test_openat()); break;