[PATCH] ntp: avoid time_offset overflows
I've been seeing some odd NTP behavior recently on a few boxes and finally narrowed it down to time_offset overflowing when converted to SHIFT_UPDATE units (which was a side effect from my HZfreeNTP patch). This patch converts time_offset from a long to a s64 which resolves the issue. [tglx@linutronix.de: signedness fixes] Signed-off-by: John Stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: john stultz <johnstul@us.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
b92c4f922b
commit
d62ac21aa0
|
@ -32,7 +32,7 @@ static u64 tick_length, tick_length_base;
|
|||
/* TIME_ERROR prevents overwriting the CMOS clock */
|
||||
static int time_state = TIME_OK; /* clock synchronization status */
|
||||
int time_status = STA_UNSYNC; /* clock status bits */
|
||||
static long time_offset; /* time adjustment (ns) */
|
||||
static s64 time_offset; /* time adjustment (ns) */
|
||||
static long time_constant = 2; /* pll time constant */
|
||||
long time_maxerror = NTP_PHASE_LIMIT; /* maximum error (us) */
|
||||
long time_esterror = NTP_PHASE_LIMIT; /* estimated error (us) */
|
||||
|
@ -196,7 +196,7 @@ void __attribute__ ((weak)) notify_arch_cmos_timer(void)
|
|||
*/
|
||||
int do_adjtimex(struct timex *txc)
|
||||
{
|
||||
long ltemp, mtemp, save_adjust;
|
||||
long mtemp, save_adjust, rem;
|
||||
s64 freq_adj, temp64;
|
||||
int result;
|
||||
|
||||
|
@ -277,14 +277,14 @@ int do_adjtimex(struct timex *txc)
|
|||
time_adjust = txc->offset;
|
||||
}
|
||||
else if (time_status & STA_PLL) {
|
||||
ltemp = txc->offset * NSEC_PER_USEC;
|
||||
time_offset = txc->offset * NSEC_PER_USEC;
|
||||
|
||||
/*
|
||||
* Scale the phase adjustment and
|
||||
* clamp to the operating range.
|
||||
*/
|
||||
time_offset = min(ltemp, MAXPHASE * NSEC_PER_USEC);
|
||||
time_offset = max(time_offset, -MAXPHASE * NSEC_PER_USEC);
|
||||
time_offset = min(time_offset, (s64)MAXPHASE * NSEC_PER_USEC);
|
||||
time_offset = max(time_offset, (s64)-MAXPHASE * NSEC_PER_USEC);
|
||||
|
||||
/*
|
||||
* Select whether the frequency is to be controlled
|
||||
|
@ -297,11 +297,11 @@ int do_adjtimex(struct timex *txc)
|
|||
mtemp = xtime.tv_sec - time_reftime;
|
||||
time_reftime = xtime.tv_sec;
|
||||
|
||||
freq_adj = (s64)time_offset * mtemp;
|
||||
freq_adj = time_offset * mtemp;
|
||||
freq_adj = shift_right(freq_adj, time_constant * 2 +
|
||||
(SHIFT_PLL + 2) * 2 - SHIFT_NSEC);
|
||||
if (mtemp >= MINSEC && (time_status & STA_FLL || mtemp > MAXSEC)) {
|
||||
temp64 = (s64)time_offset << (SHIFT_NSEC - SHIFT_FLL);
|
||||
temp64 = time_offset << (SHIFT_NSEC - SHIFT_FLL);
|
||||
if (time_offset < 0) {
|
||||
temp64 = -temp64;
|
||||
do_div(temp64, mtemp);
|
||||
|
@ -314,8 +314,10 @@ int do_adjtimex(struct timex *txc)
|
|||
freq_adj += time_freq;
|
||||
freq_adj = min(freq_adj, (s64)MAXFREQ_NSEC);
|
||||
time_freq = max(freq_adj, (s64)-MAXFREQ_NSEC);
|
||||
time_offset = (time_offset / NTP_INTERVAL_FREQ)
|
||||
<< SHIFT_UPDATE;
|
||||
time_offset = div_long_long_rem_signed(time_offset,
|
||||
NTP_INTERVAL_FREQ,
|
||||
&rem);
|
||||
time_offset <<= SHIFT_UPDATE;
|
||||
} /* STA_PLL */
|
||||
} /* txc->modes & ADJ_OFFSET */
|
||||
if (txc->modes & ADJ_TICK)
|
||||
|
@ -330,10 +332,10 @@ leave: if ((time_status & (STA_UNSYNC|STA_CLOCKERR)) != 0)
|
|||
if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
|
||||
txc->offset = save_adjust;
|
||||
else
|
||||
txc->offset = shift_right(time_offset, SHIFT_UPDATE)
|
||||
* NTP_INTERVAL_FREQ / 1000;
|
||||
txc->freq = (time_freq / NSEC_PER_USEC)
|
||||
<< (SHIFT_USEC - SHIFT_NSEC);
|
||||
txc->offset = ((long)shift_right(time_offset, SHIFT_UPDATE)) *
|
||||
NTP_INTERVAL_FREQ / 1000;
|
||||
txc->freq = (time_freq / NSEC_PER_USEC) <<
|
||||
(SHIFT_USEC - SHIFT_NSEC);
|
||||
txc->maxerror = time_maxerror;
|
||||
txc->esterror = time_esterror;
|
||||
txc->status = time_status;
|
||||
|
|
Loading…
Reference in a new issue