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.

thanks
-john

Signed-off-by: John Stultz <[EMAIL PROTECTED]>

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index eb12509..eaa3d24 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -32,7 +32,7 @@ #define MAX_TICKADJ_SCALED    (((u64)(MAX_T
 /* 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_
  */
 int do_adjtimex(struct timex *txc)
 {
-       long ltemp, mtemp, save_adjust;
+       long mtemp, save_adjust;
        s64 freq_adj, temp64;
        int result;
 
@@ -277,14 +277,14 @@ #endif
                    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 @@ #endif
                    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 +314,8 @@ #endif
                    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;
+                   do_div(time_offset, NTP_INTERVAL_FREQ);
+                   time_offset <<= SHIFT_UPDATE;
                } /* STA_PLL */
            } /* txc->modes & ADJ_OFFSET */
            if (txc->modes & ADJ_TICK)
@@ -330,7 +330,7 @@ leave:      if ((time_status & (STA_UNSYNC|ST
        if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
            txc->offset    = save_adjust;
        else
-           txc->offset    = shift_right(time_offset, SHIFT_UPDATE)
+           txc->offset    = ((long)shift_right(time_offset, SHIFT_UPDATE))
                                * NTP_INTERVAL_FREQ / 1000;
        txc->freq          = (time_freq / NSEC_PER_USEC)
                                << (SHIFT_USEC - SHIFT_NSEC);



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to