tools/nolibc: fall back to sys_clock_gettime() in gettimeofday()

Newer architectures (like riscv32) do not implement sys_gettimeofday().
In those cases fall back to sys_clock_gettime().
While that does not support the timezone argument of sys_gettimeofday(),
specifying this argument invokes undefined behaviour, so it's safe to ignore.

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-v2-14-3c043eeab06c@linutronix.de
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

diff --git a/tools/include/nolibc/sys/time.h b/tools/include/nolibc/sys/time.h
index 785961c52fa3b6606ee30c19a4a1c11e86ccacc0..33782a19aae92907ccc636a656fc0f27b838dd61 100644 (file)
--- a/tools/include/nolibc/sys/time.h
+++ b/tools/include/nolibc/sys/time.h
@@ -13,6 +13,8 @@
 #include "../arch.h"
 #include "../sys.h"
 
+static int sys_clock_gettime(clockid_t clockid, struct timespec *tp);
+
 /*
  * int gettimeofday(struct timeval *tv, struct timezone *tz);
  */
@@ -23,7 +25,18 @@ int sys_gettimeofday(struct timeval *tv, struct timezone *tz)
 #ifdef __NR_gettimeofday
        return my_syscall2(__NR_gettimeofday, tv, tz);
 #else
-       return __nolibc_enosys(__func__, tv, tz);
+       (void) tz; /* Non-NULL tz is undefined behaviour */
+
+       struct timespec tp;
+       int ret;
+
+       ret = sys_clock_gettime(CLOCK_REALTIME, &tp);
+       if (!ret && tv) {
+               tv->tv_sec = tp.tv_sec;
+               tv->tv_usec = tp.tv_nsec / 1000;
+       }
+
+       return ret;
 #endif
 }