tools/nolibc: add clock_getres(), clock_gettime() and clock_settime()

This is used in various selftests and will be handy when integrating
those with nolibc.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://lore.kernel.org/r/20250428-nolibc-misc-v2-8-3c043eeab06c@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

tools/include/nolibc/time.h

@@ -15,6 +15,98 @@
 #include "types.h"
 #include "sys.h"
 
+#include <linux/time.h>
+
+static __inline__
+void __nolibc_timespec_user_to_kernel(const struct timespec *ts, struct __kernel_timespec *kts)
+{
+	kts->tv_sec = ts->tv_sec;
+	kts->tv_nsec = ts->tv_nsec;
+}
+
+static __inline__
+void __nolibc_timespec_kernel_to_user(const struct __kernel_timespec *kts, struct timespec *ts)
+{
+	ts->tv_sec = kts->tv_sec;
+	ts->tv_nsec = kts->tv_nsec;
+}
+
+/*
+ * 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);
+ */
+
+static __attribute__((unused))
+int sys_clock_getres(clockid_t clockid, struct timespec *res)
+{
+#if defined(__NR_clock_getres)
+	return my_syscall2(__NR_clock_getres, clockid, res);
+#elif defined(__NR_clock_getres_time64)
+	struct __kernel_timespec kres;
+	int ret;
+
+	ret = my_syscall2(__NR_clock_getres_time64, clockid, &kres);
+	if (res)
+		__nolibc_timespec_kernel_to_user(&kres, res);
+	return ret;
+#else
+	return __nolibc_enosys(__func__, clockid, res);
+#endif
+}
+
+static __attribute__((unused))
+int clock_getres(clockid_t clockid, struct timespec *res)
+{
+	return __sysret(sys_clock_getres(clockid, res));
+}
+
+static __attribute__((unused))
+int sys_clock_gettime(clockid_t clockid, struct timespec *tp)
+{
+#if defined(__NR_clock_gettime)
+	return my_syscall2(__NR_clock_gettime, clockid, tp);
+#elif defined(__NR_clock_gettime64)
+	struct __kernel_timespec ktp;
+	int ret;
+
+	ret = my_syscall2(__NR_clock_gettime64, clockid, &ktp);
+	if (tp)
+		__nolibc_timespec_kernel_to_user(&ktp, tp);
+	return ret;
+#else
+	return __nolibc_enosys(__func__, clockid, tp);
+#endif
+}
+
+static __attribute__((unused))
+int clock_gettime(clockid_t clockid, struct timespec *tp)
+{
+	return __sysret(sys_clock_gettime(clockid, tp));
+}
+
+static __attribute__((unused))
+int sys_clock_settime(clockid_t clockid, struct timespec *tp)
+{
+#if defined(__NR_clock_settime)
+	return my_syscall2(__NR_clock_settime, clockid, tp);
+#elif defined(__NR_clock_settime64)
+	struct __kernel_timespec ktp;
+
+	__nolibc_timespec_user_to_kernel(tp, &ktp);
+	return my_syscall2(__NR_clock_settime64, clockid, &ktp);
+#else
+	return __nolibc_enosys(__func__, clockid, tp);
+#endif
+}
+
+static __attribute__((unused))
+int clock_settime(clockid_t clockid, struct timespec *tp)
+{
+	return __sysret(sys_clock_settime(clockid, tp));
+}
+
+
 static __attribute__((unused))
 time_t time(time_t *tptr)
 {

tools/include/nolibc/types.h

@@ -187,6 +187,8 @@ struct stat {
 	union { time_t st_ctime; struct timespec st_ctim; }; /* time of last status change */
 };
 
+typedef __kernel_clockid_t clockid_t;
+
 /* WARNING, it only deals with the 4096 first majors and 256 first minors */
 #define makedev(major, minor) ((dev_t)((((major) & 0xfff) << 8) | ((minor) & 0xff)))
 #define major(dev) ((unsigned int)(((dev) >> 8) & 0xfff))

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

@@ -38,6 +38,7 @@
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <time.h>
 #include <unistd.h>
 #include <limits.h>
 #include <ctype.h>
@@ -1081,6 +1082,7 @@ int run_syscall(int min, int max)
 {
 	struct timeval tv;
 	struct timezone tz;
+	struct timespec ts;
 	struct stat stat_buf;
 	int euid0;
 	int proc;
@@ -1114,6 +1116,9 @@ int run_syscall(int min, int max)
 		switch (test + __LINE__ + 1) {
 		CASE_TEST(access);            EXPECT_SYSZR(proc, access("/proc/self", R_OK)); break;
 		CASE_TEST(access_bad);        EXPECT_SYSER(proc, access("/proc/self", W_OK), -1, EPERM); break;
+		CASE_TEST(clock_getres);      EXPECT_SYSZR(1, clock_getres(CLOCK_MONOTONIC, &ts)); break;
+		CASE_TEST(clock_gettime);     EXPECT_SYSZR(1, clock_gettime(CLOCK_MONOTONIC, &ts)); break;
+		CASE_TEST(clock_settime);     EXPECT_SYSER(1, clock_settime(CLOCK_MONOTONIC, &ts), -1, EINVAL); break;
 		CASE_TEST(getpid);            EXPECT_SYSNE(1, getpid(), -1); break;
 		CASE_TEST(getppid);           EXPECT_SYSNE(1, getppid(), -1); break;
 		CASE_TEST(gettid);            EXPECT_SYSNE(has_gettid, gettid(), -1); break;