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kernel: high-hz workaround for do_settime

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. with hz=1000, clock_t only lasts a few years.
	  whenever we can't express the desired realtime
	  in ticks because the distance with boottime is
	  too high, simply adjust bootime like we do for
	  otherwise negative values.
	. fixes test 2 on ARM
This commit is contained in:
Ben Gras 2013-06-24 15:46:20 +02:00
parent bb268230c4
commit 27f7fd3554
1 changed files with 7 additions and 3 deletions
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10
kernel/system/do_settime.c
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@ -19,6 +19,7 @@ int do_settime(struct proc * caller, message * m_ptr)
{
clock_t newclock, ticks;
time_t timediff;
signed long long timediff_ticks;
if (m_ptr->T_CLOCK_ID != CLOCK_REALTIME) /* only realtime can change */
return EINVAL;
@ -31,8 +32,12 @@ int do_settime(struct proc * caller, message * m_ptr)
return(OK);
} /* else user wants to set the time */
timediff = m_ptr->T_TIME_SEC - boottime;
timediff_ticks = (signed long long) timediff * system_hz;
/* prevent a negative value for realtime */
if (m_ptr->T_TIME_SEC <= boottime) {
if (m_ptr->T_TIME_SEC <= boottime ||
timediff_ticks < LONG_MIN/2 || timediff_ticks > LONG_MAX/2) {
/* boottime was likely wrong, try to correct it. */
boottime = m_ptr->T_TIME_SEC;
set_realtime(1);
@ -40,8 +45,7 @@ int do_settime(struct proc * caller, message * m_ptr)
}
/* calculate the new value of realtime in ticks */
timediff = m_ptr->T_TIME_SEC - boottime;
newclock = (timediff*system_hz) + (m_ptr->T_TIME_NSEC/(1000000000/system_hz));
newclock = timediff_ticks + (m_ptr->T_TIME_NSEC/(1000000000/system_hz));
set_realtime(newclock);