The glibc implementation of adjtime(delta, old_delta) should return
the remaining time adjustment value from adjtimex() in old_delta if that
argument is non-NULL.
This is broken in the case that delta is NULL (i.e., we don't want
a change, but just to find out the current time_adjust). The breakage
occurs because adjtime specifies txc->modes as 0 (so that no change
is made to the current offset) and in this case do_adjtimex() does not
correctly return the required information in txc->offset.
The patch below (against 2.4.18pre10) seems to me the simplest way to
fix the problem.
Cheers,
Michael
--- linux-2.4.18/kernel/time.c Fri Jun 14 10:17:46 2002
+++ linux-2.4.18-adjtimex/kernel/time.c Fri Jun 14 09:48:59 2002
@@ -357,7 +357,9 @@
/* p. 24, (d) */
result = TIME_ERROR;
- if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
+ if (!txc->modes)
+ txc->offset = time_adjust;
+ else if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
txc->offset = save_adjust;
else {
if (time_offset < 0)