mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-11-01 17:08:10 +00:00
dd4e17ab70
Recently, in commit37cf4dc337
I forgot to check if the timeval being passed was actually a timespec (as is signaled with ADJ_NANO). This resulted in that patch breaking ADJ_SETOFFSET users who set ADJ_NANO, by rejecting valid timespecs that were compared with valid timeval ranges. This patch addresses this by checking for the ADJ_NANO flag and using the timepsec check instead in that case. Reported-by: Harald Hoyer <harald@redhat.com> Reported-by: Kay Sievers <kay@vrfy.org> Fixes:37cf4dc337
"time: Verify time values in adjtimex ADJ_SETOFFSET to avoid overflow" Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: David Herrmann <dh.herrmann@gmail.com> Link: http://lkml.kernel.org/r/1453417415-19110-2-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
1039 lines
26 KiB
C
1039 lines
26 KiB
C
/*
|
|
* NTP state machine interfaces and logic.
|
|
*
|
|
* This code was mainly moved from kernel/timer.c and kernel/time.c
|
|
* Please see those files for relevant copyright info and historical
|
|
* changelogs.
|
|
*/
|
|
#include <linux/capability.h>
|
|
#include <linux/clocksource.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/hrtimer.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/math64.h>
|
|
#include <linux/timex.h>
|
|
#include <linux/time.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/module.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/math64.h>
|
|
|
|
#include "ntp_internal.h"
|
|
#include "timekeeping_internal.h"
|
|
|
|
|
|
/*
|
|
* NTP timekeeping variables:
|
|
*
|
|
* Note: All of the NTP state is protected by the timekeeping locks.
|
|
*/
|
|
|
|
|
|
/* USER_HZ period (usecs): */
|
|
unsigned long tick_usec = TICK_USEC;
|
|
|
|
/* SHIFTED_HZ period (nsecs): */
|
|
unsigned long tick_nsec;
|
|
|
|
static u64 tick_length;
|
|
static u64 tick_length_base;
|
|
|
|
#define SECS_PER_DAY 86400
|
|
#define MAX_TICKADJ 500LL /* usecs */
|
|
#define MAX_TICKADJ_SCALED \
|
|
(((MAX_TICKADJ * NSEC_PER_USEC) << NTP_SCALE_SHIFT) / NTP_INTERVAL_FREQ)
|
|
|
|
/*
|
|
* phase-lock loop variables
|
|
*/
|
|
|
|
/*
|
|
* clock synchronization status
|
|
*
|
|
* (TIME_ERROR prevents overwriting the CMOS clock)
|
|
*/
|
|
static int time_state = TIME_OK;
|
|
|
|
/* clock status bits: */
|
|
static int time_status = STA_UNSYNC;
|
|
|
|
/* time adjustment (nsecs): */
|
|
static s64 time_offset;
|
|
|
|
/* pll time constant: */
|
|
static long time_constant = 2;
|
|
|
|
/* maximum error (usecs): */
|
|
static long time_maxerror = NTP_PHASE_LIMIT;
|
|
|
|
/* estimated error (usecs): */
|
|
static long time_esterror = NTP_PHASE_LIMIT;
|
|
|
|
/* frequency offset (scaled nsecs/secs): */
|
|
static s64 time_freq;
|
|
|
|
/* time at last adjustment (secs): */
|
|
static time64_t time_reftime;
|
|
|
|
static long time_adjust;
|
|
|
|
/* constant (boot-param configurable) NTP tick adjustment (upscaled) */
|
|
static s64 ntp_tick_adj;
|
|
|
|
/* second value of the next pending leapsecond, or TIME64_MAX if no leap */
|
|
static time64_t ntp_next_leap_sec = TIME64_MAX;
|
|
|
|
#ifdef CONFIG_NTP_PPS
|
|
|
|
/*
|
|
* The following variables are used when a pulse-per-second (PPS) signal
|
|
* is available. They establish the engineering parameters of the clock
|
|
* discipline loop when controlled by the PPS signal.
|
|
*/
|
|
#define PPS_VALID 10 /* PPS signal watchdog max (s) */
|
|
#define PPS_POPCORN 4 /* popcorn spike threshold (shift) */
|
|
#define PPS_INTMIN 2 /* min freq interval (s) (shift) */
|
|
#define PPS_INTMAX 8 /* max freq interval (s) (shift) */
|
|
#define PPS_INTCOUNT 4 /* number of consecutive good intervals to
|
|
increase pps_shift or consecutive bad
|
|
intervals to decrease it */
|
|
#define PPS_MAXWANDER 100000 /* max PPS freq wander (ns/s) */
|
|
|
|
static int pps_valid; /* signal watchdog counter */
|
|
static long pps_tf[3]; /* phase median filter */
|
|
static long pps_jitter; /* current jitter (ns) */
|
|
static struct timespec64 pps_fbase; /* beginning of the last freq interval */
|
|
static int pps_shift; /* current interval duration (s) (shift) */
|
|
static int pps_intcnt; /* interval counter */
|
|
static s64 pps_freq; /* frequency offset (scaled ns/s) */
|
|
static long pps_stabil; /* current stability (scaled ns/s) */
|
|
|
|
/*
|
|
* PPS signal quality monitors
|
|
*/
|
|
static long pps_calcnt; /* calibration intervals */
|
|
static long pps_jitcnt; /* jitter limit exceeded */
|
|
static long pps_stbcnt; /* stability limit exceeded */
|
|
static long pps_errcnt; /* calibration errors */
|
|
|
|
|
|
/* PPS kernel consumer compensates the whole phase error immediately.
|
|
* Otherwise, reduce the offset by a fixed factor times the time constant.
|
|
*/
|
|
static inline s64 ntp_offset_chunk(s64 offset)
|
|
{
|
|
if (time_status & STA_PPSTIME && time_status & STA_PPSSIGNAL)
|
|
return offset;
|
|
else
|
|
return shift_right(offset, SHIFT_PLL + time_constant);
|
|
}
|
|
|
|
static inline void pps_reset_freq_interval(void)
|
|
{
|
|
/* the PPS calibration interval may end
|
|
surprisingly early */
|
|
pps_shift = PPS_INTMIN;
|
|
pps_intcnt = 0;
|
|
}
|
|
|
|
/**
|
|
* pps_clear - Clears the PPS state variables
|
|
*/
|
|
static inline void pps_clear(void)
|
|
{
|
|
pps_reset_freq_interval();
|
|
pps_tf[0] = 0;
|
|
pps_tf[1] = 0;
|
|
pps_tf[2] = 0;
|
|
pps_fbase.tv_sec = pps_fbase.tv_nsec = 0;
|
|
pps_freq = 0;
|
|
}
|
|
|
|
/* Decrease pps_valid to indicate that another second has passed since
|
|
* the last PPS signal. When it reaches 0, indicate that PPS signal is
|
|
* missing.
|
|
*/
|
|
static inline void pps_dec_valid(void)
|
|
{
|
|
if (pps_valid > 0)
|
|
pps_valid--;
|
|
else {
|
|
time_status &= ~(STA_PPSSIGNAL | STA_PPSJITTER |
|
|
STA_PPSWANDER | STA_PPSERROR);
|
|
pps_clear();
|
|
}
|
|
}
|
|
|
|
static inline void pps_set_freq(s64 freq)
|
|
{
|
|
pps_freq = freq;
|
|
}
|
|
|
|
static inline int is_error_status(int status)
|
|
{
|
|
return (status & (STA_UNSYNC|STA_CLOCKERR))
|
|
/* PPS signal lost when either PPS time or
|
|
* PPS frequency synchronization requested
|
|
*/
|
|
|| ((status & (STA_PPSFREQ|STA_PPSTIME))
|
|
&& !(status & STA_PPSSIGNAL))
|
|
/* PPS jitter exceeded when
|
|
* PPS time synchronization requested */
|
|
|| ((status & (STA_PPSTIME|STA_PPSJITTER))
|
|
== (STA_PPSTIME|STA_PPSJITTER))
|
|
/* PPS wander exceeded or calibration error when
|
|
* PPS frequency synchronization requested
|
|
*/
|
|
|| ((status & STA_PPSFREQ)
|
|
&& (status & (STA_PPSWANDER|STA_PPSERROR)));
|
|
}
|
|
|
|
static inline void pps_fill_timex(struct timex *txc)
|
|
{
|
|
txc->ppsfreq = shift_right((pps_freq >> PPM_SCALE_INV_SHIFT) *
|
|
PPM_SCALE_INV, NTP_SCALE_SHIFT);
|
|
txc->jitter = pps_jitter;
|
|
if (!(time_status & STA_NANO))
|
|
txc->jitter /= NSEC_PER_USEC;
|
|
txc->shift = pps_shift;
|
|
txc->stabil = pps_stabil;
|
|
txc->jitcnt = pps_jitcnt;
|
|
txc->calcnt = pps_calcnt;
|
|
txc->errcnt = pps_errcnt;
|
|
txc->stbcnt = pps_stbcnt;
|
|
}
|
|
|
|
#else /* !CONFIG_NTP_PPS */
|
|
|
|
static inline s64 ntp_offset_chunk(s64 offset)
|
|
{
|
|
return shift_right(offset, SHIFT_PLL + time_constant);
|
|
}
|
|
|
|
static inline void pps_reset_freq_interval(void) {}
|
|
static inline void pps_clear(void) {}
|
|
static inline void pps_dec_valid(void) {}
|
|
static inline void pps_set_freq(s64 freq) {}
|
|
|
|
static inline int is_error_status(int status)
|
|
{
|
|
return status & (STA_UNSYNC|STA_CLOCKERR);
|
|
}
|
|
|
|
static inline void pps_fill_timex(struct timex *txc)
|
|
{
|
|
/* PPS is not implemented, so these are zero */
|
|
txc->ppsfreq = 0;
|
|
txc->jitter = 0;
|
|
txc->shift = 0;
|
|
txc->stabil = 0;
|
|
txc->jitcnt = 0;
|
|
txc->calcnt = 0;
|
|
txc->errcnt = 0;
|
|
txc->stbcnt = 0;
|
|
}
|
|
|
|
#endif /* CONFIG_NTP_PPS */
|
|
|
|
|
|
/**
|
|
* ntp_synced - Returns 1 if the NTP status is not UNSYNC
|
|
*
|
|
*/
|
|
static inline int ntp_synced(void)
|
|
{
|
|
return !(time_status & STA_UNSYNC);
|
|
}
|
|
|
|
|
|
/*
|
|
* NTP methods:
|
|
*/
|
|
|
|
/*
|
|
* Update (tick_length, tick_length_base, tick_nsec), based
|
|
* on (tick_usec, ntp_tick_adj, time_freq):
|
|
*/
|
|
static void ntp_update_frequency(void)
|
|
{
|
|
u64 second_length;
|
|
u64 new_base;
|
|
|
|
second_length = (u64)(tick_usec * NSEC_PER_USEC * USER_HZ)
|
|
<< NTP_SCALE_SHIFT;
|
|
|
|
second_length += ntp_tick_adj;
|
|
second_length += time_freq;
|
|
|
|
tick_nsec = div_u64(second_length, HZ) >> NTP_SCALE_SHIFT;
|
|
new_base = div_u64(second_length, NTP_INTERVAL_FREQ);
|
|
|
|
/*
|
|
* Don't wait for the next second_overflow, apply
|
|
* the change to the tick length immediately:
|
|
*/
|
|
tick_length += new_base - tick_length_base;
|
|
tick_length_base = new_base;
|
|
}
|
|
|
|
static inline s64 ntp_update_offset_fll(s64 offset64, long secs)
|
|
{
|
|
time_status &= ~STA_MODE;
|
|
|
|
if (secs < MINSEC)
|
|
return 0;
|
|
|
|
if (!(time_status & STA_FLL) && (secs <= MAXSEC))
|
|
return 0;
|
|
|
|
time_status |= STA_MODE;
|
|
|
|
return div64_long(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
|
|
}
|
|
|
|
static void ntp_update_offset(long offset)
|
|
{
|
|
s64 freq_adj;
|
|
s64 offset64;
|
|
long secs;
|
|
|
|
if (!(time_status & STA_PLL))
|
|
return;
|
|
|
|
if (!(time_status & STA_NANO)) {
|
|
/* Make sure the multiplication below won't overflow */
|
|
offset = clamp(offset, -USEC_PER_SEC, USEC_PER_SEC);
|
|
offset *= NSEC_PER_USEC;
|
|
}
|
|
|
|
/*
|
|
* Scale the phase adjustment and
|
|
* clamp to the operating range.
|
|
*/
|
|
offset = clamp(offset, -MAXPHASE, MAXPHASE);
|
|
|
|
/*
|
|
* Select how the frequency is to be controlled
|
|
* and in which mode (PLL or FLL).
|
|
*/
|
|
secs = (long)(__ktime_get_real_seconds() - time_reftime);
|
|
if (unlikely(time_status & STA_FREQHOLD))
|
|
secs = 0;
|
|
|
|
time_reftime = __ktime_get_real_seconds();
|
|
|
|
offset64 = offset;
|
|
freq_adj = ntp_update_offset_fll(offset64, secs);
|
|
|
|
/*
|
|
* Clamp update interval to reduce PLL gain with low
|
|
* sampling rate (e.g. intermittent network connection)
|
|
* to avoid instability.
|
|
*/
|
|
if (unlikely(secs > 1 << (SHIFT_PLL + 1 + time_constant)))
|
|
secs = 1 << (SHIFT_PLL + 1 + time_constant);
|
|
|
|
freq_adj += (offset64 * secs) <<
|
|
(NTP_SCALE_SHIFT - 2 * (SHIFT_PLL + 2 + time_constant));
|
|
|
|
freq_adj = min(freq_adj + time_freq, MAXFREQ_SCALED);
|
|
|
|
time_freq = max(freq_adj, -MAXFREQ_SCALED);
|
|
|
|
time_offset = div_s64(offset64 << NTP_SCALE_SHIFT, NTP_INTERVAL_FREQ);
|
|
}
|
|
|
|
/**
|
|
* ntp_clear - Clears the NTP state variables
|
|
*/
|
|
void ntp_clear(void)
|
|
{
|
|
time_adjust = 0; /* stop active adjtime() */
|
|
time_status |= STA_UNSYNC;
|
|
time_maxerror = NTP_PHASE_LIMIT;
|
|
time_esterror = NTP_PHASE_LIMIT;
|
|
|
|
ntp_update_frequency();
|
|
|
|
tick_length = tick_length_base;
|
|
time_offset = 0;
|
|
|
|
ntp_next_leap_sec = TIME64_MAX;
|
|
/* Clear PPS state variables */
|
|
pps_clear();
|
|
}
|
|
|
|
|
|
u64 ntp_tick_length(void)
|
|
{
|
|
return tick_length;
|
|
}
|
|
|
|
/**
|
|
* ntp_get_next_leap - Returns the next leapsecond in CLOCK_REALTIME ktime_t
|
|
*
|
|
* Provides the time of the next leapsecond against CLOCK_REALTIME in
|
|
* a ktime_t format. Returns KTIME_MAX if no leapsecond is pending.
|
|
*/
|
|
ktime_t ntp_get_next_leap(void)
|
|
{
|
|
ktime_t ret;
|
|
|
|
if ((time_state == TIME_INS) && (time_status & STA_INS))
|
|
return ktime_set(ntp_next_leap_sec, 0);
|
|
ret.tv64 = KTIME_MAX;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* this routine handles the overflow of the microsecond field
|
|
*
|
|
* The tricky bits of code to handle the accurate clock support
|
|
* were provided by Dave Mills (Mills@UDEL.EDU) of NTP fame.
|
|
* They were originally developed for SUN and DEC kernels.
|
|
* All the kudos should go to Dave for this stuff.
|
|
*
|
|
* Also handles leap second processing, and returns leap offset
|
|
*/
|
|
int second_overflow(time64_t secs)
|
|
{
|
|
s64 delta;
|
|
int leap = 0;
|
|
s32 rem;
|
|
|
|
/*
|
|
* Leap second processing. If in leap-insert state at the end of the
|
|
* day, the system clock is set back one second; if in leap-delete
|
|
* state, the system clock is set ahead one second.
|
|
*/
|
|
switch (time_state) {
|
|
case TIME_OK:
|
|
if (time_status & STA_INS) {
|
|
time_state = TIME_INS;
|
|
div_s64_rem(secs, SECS_PER_DAY, &rem);
|
|
ntp_next_leap_sec = secs + SECS_PER_DAY - rem;
|
|
} else if (time_status & STA_DEL) {
|
|
time_state = TIME_DEL;
|
|
div_s64_rem(secs + 1, SECS_PER_DAY, &rem);
|
|
ntp_next_leap_sec = secs + SECS_PER_DAY - rem;
|
|
}
|
|
break;
|
|
case TIME_INS:
|
|
if (!(time_status & STA_INS)) {
|
|
ntp_next_leap_sec = TIME64_MAX;
|
|
time_state = TIME_OK;
|
|
} else if (secs == ntp_next_leap_sec) {
|
|
leap = -1;
|
|
time_state = TIME_OOP;
|
|
printk(KERN_NOTICE
|
|
"Clock: inserting leap second 23:59:60 UTC\n");
|
|
}
|
|
break;
|
|
case TIME_DEL:
|
|
if (!(time_status & STA_DEL)) {
|
|
ntp_next_leap_sec = TIME64_MAX;
|
|
time_state = TIME_OK;
|
|
} else if (secs == ntp_next_leap_sec) {
|
|
leap = 1;
|
|
ntp_next_leap_sec = TIME64_MAX;
|
|
time_state = TIME_WAIT;
|
|
printk(KERN_NOTICE
|
|
"Clock: deleting leap second 23:59:59 UTC\n");
|
|
}
|
|
break;
|
|
case TIME_OOP:
|
|
ntp_next_leap_sec = TIME64_MAX;
|
|
time_state = TIME_WAIT;
|
|
break;
|
|
case TIME_WAIT:
|
|
if (!(time_status & (STA_INS | STA_DEL)))
|
|
time_state = TIME_OK;
|
|
break;
|
|
}
|
|
|
|
|
|
/* Bump the maxerror field */
|
|
time_maxerror += MAXFREQ / NSEC_PER_USEC;
|
|
if (time_maxerror > NTP_PHASE_LIMIT) {
|
|
time_maxerror = NTP_PHASE_LIMIT;
|
|
time_status |= STA_UNSYNC;
|
|
}
|
|
|
|
/* Compute the phase adjustment for the next second */
|
|
tick_length = tick_length_base;
|
|
|
|
delta = ntp_offset_chunk(time_offset);
|
|
time_offset -= delta;
|
|
tick_length += delta;
|
|
|
|
/* Check PPS signal */
|
|
pps_dec_valid();
|
|
|
|
if (!time_adjust)
|
|
goto out;
|
|
|
|
if (time_adjust > MAX_TICKADJ) {
|
|
time_adjust -= MAX_TICKADJ;
|
|
tick_length += MAX_TICKADJ_SCALED;
|
|
goto out;
|
|
}
|
|
|
|
if (time_adjust < -MAX_TICKADJ) {
|
|
time_adjust += MAX_TICKADJ;
|
|
tick_length -= MAX_TICKADJ_SCALED;
|
|
goto out;
|
|
}
|
|
|
|
tick_length += (s64)(time_adjust * NSEC_PER_USEC / NTP_INTERVAL_FREQ)
|
|
<< NTP_SCALE_SHIFT;
|
|
time_adjust = 0;
|
|
|
|
out:
|
|
return leap;
|
|
}
|
|
|
|
#ifdef CONFIG_GENERIC_CMOS_UPDATE
|
|
int __weak update_persistent_clock(struct timespec now)
|
|
{
|
|
return -ENODEV;
|
|
}
|
|
|
|
int __weak update_persistent_clock64(struct timespec64 now64)
|
|
{
|
|
struct timespec now;
|
|
|
|
now = timespec64_to_timespec(now64);
|
|
return update_persistent_clock(now);
|
|
}
|
|
#endif
|
|
|
|
#if defined(CONFIG_GENERIC_CMOS_UPDATE) || defined(CONFIG_RTC_SYSTOHC)
|
|
static void sync_cmos_clock(struct work_struct *work);
|
|
|
|
static DECLARE_DELAYED_WORK(sync_cmos_work, sync_cmos_clock);
|
|
|
|
static void sync_cmos_clock(struct work_struct *work)
|
|
{
|
|
struct timespec64 now;
|
|
struct timespec64 next;
|
|
int fail = 1;
|
|
|
|
/*
|
|
* If we have an externally synchronized Linux clock, then update
|
|
* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
|
|
* called as close as possible to 500 ms before the new second starts.
|
|
* This code is run on a timer. If the clock is set, that timer
|
|
* may not expire at the correct time. Thus, we adjust...
|
|
* We want the clock to be within a couple of ticks from the target.
|
|
*/
|
|
if (!ntp_synced()) {
|
|
/*
|
|
* Not synced, exit, do not restart a timer (if one is
|
|
* running, let it run out).
|
|
*/
|
|
return;
|
|
}
|
|
|
|
getnstimeofday64(&now);
|
|
if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec * 5) {
|
|
struct timespec64 adjust = now;
|
|
|
|
fail = -ENODEV;
|
|
if (persistent_clock_is_local)
|
|
adjust.tv_sec -= (sys_tz.tz_minuteswest * 60);
|
|
#ifdef CONFIG_GENERIC_CMOS_UPDATE
|
|
fail = update_persistent_clock64(adjust);
|
|
#endif
|
|
|
|
#ifdef CONFIG_RTC_SYSTOHC
|
|
if (fail == -ENODEV)
|
|
fail = rtc_set_ntp_time(adjust);
|
|
#endif
|
|
}
|
|
|
|
next.tv_nsec = (NSEC_PER_SEC / 2) - now.tv_nsec - (TICK_NSEC / 2);
|
|
if (next.tv_nsec <= 0)
|
|
next.tv_nsec += NSEC_PER_SEC;
|
|
|
|
if (!fail || fail == -ENODEV)
|
|
next.tv_sec = 659;
|
|
else
|
|
next.tv_sec = 0;
|
|
|
|
if (next.tv_nsec >= NSEC_PER_SEC) {
|
|
next.tv_sec++;
|
|
next.tv_nsec -= NSEC_PER_SEC;
|
|
}
|
|
queue_delayed_work(system_power_efficient_wq,
|
|
&sync_cmos_work, timespec64_to_jiffies(&next));
|
|
}
|
|
|
|
void ntp_notify_cmos_timer(void)
|
|
{
|
|
queue_delayed_work(system_power_efficient_wq, &sync_cmos_work, 0);
|
|
}
|
|
|
|
#else
|
|
void ntp_notify_cmos_timer(void) { }
|
|
#endif
|
|
|
|
|
|
/*
|
|
* Propagate a new txc->status value into the NTP state:
|
|
*/
|
|
static inline void process_adj_status(struct timex *txc, struct timespec64 *ts)
|
|
{
|
|
if ((time_status & STA_PLL) && !(txc->status & STA_PLL)) {
|
|
time_state = TIME_OK;
|
|
time_status = STA_UNSYNC;
|
|
ntp_next_leap_sec = TIME64_MAX;
|
|
/* restart PPS frequency calibration */
|
|
pps_reset_freq_interval();
|
|
}
|
|
|
|
/*
|
|
* If we turn on PLL adjustments then reset the
|
|
* reference time to current time.
|
|
*/
|
|
if (!(time_status & STA_PLL) && (txc->status & STA_PLL))
|
|
time_reftime = __ktime_get_real_seconds();
|
|
|
|
/* only set allowed bits */
|
|
time_status &= STA_RONLY;
|
|
time_status |= txc->status & ~STA_RONLY;
|
|
}
|
|
|
|
|
|
static inline void process_adjtimex_modes(struct timex *txc,
|
|
struct timespec64 *ts,
|
|
s32 *time_tai)
|
|
{
|
|
if (txc->modes & ADJ_STATUS)
|
|
process_adj_status(txc, ts);
|
|
|
|
if (txc->modes & ADJ_NANO)
|
|
time_status |= STA_NANO;
|
|
|
|
if (txc->modes & ADJ_MICRO)
|
|
time_status &= ~STA_NANO;
|
|
|
|
if (txc->modes & ADJ_FREQUENCY) {
|
|
time_freq = txc->freq * PPM_SCALE;
|
|
time_freq = min(time_freq, MAXFREQ_SCALED);
|
|
time_freq = max(time_freq, -MAXFREQ_SCALED);
|
|
/* update pps_freq */
|
|
pps_set_freq(time_freq);
|
|
}
|
|
|
|
if (txc->modes & ADJ_MAXERROR)
|
|
time_maxerror = txc->maxerror;
|
|
|
|
if (txc->modes & ADJ_ESTERROR)
|
|
time_esterror = txc->esterror;
|
|
|
|
if (txc->modes & ADJ_TIMECONST) {
|
|
time_constant = txc->constant;
|
|
if (!(time_status & STA_NANO))
|
|
time_constant += 4;
|
|
time_constant = min(time_constant, (long)MAXTC);
|
|
time_constant = max(time_constant, 0l);
|
|
}
|
|
|
|
if (txc->modes & ADJ_TAI && txc->constant > 0)
|
|
*time_tai = txc->constant;
|
|
|
|
if (txc->modes & ADJ_OFFSET)
|
|
ntp_update_offset(txc->offset);
|
|
|
|
if (txc->modes & ADJ_TICK)
|
|
tick_usec = txc->tick;
|
|
|
|
if (txc->modes & (ADJ_TICK|ADJ_FREQUENCY|ADJ_OFFSET))
|
|
ntp_update_frequency();
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* ntp_validate_timex - Ensures the timex is ok for use in do_adjtimex
|
|
*/
|
|
int ntp_validate_timex(struct timex *txc)
|
|
{
|
|
if (txc->modes & ADJ_ADJTIME) {
|
|
/* singleshot must not be used with any other mode bits */
|
|
if (!(txc->modes & ADJ_OFFSET_SINGLESHOT))
|
|
return -EINVAL;
|
|
if (!(txc->modes & ADJ_OFFSET_READONLY) &&
|
|
!capable(CAP_SYS_TIME))
|
|
return -EPERM;
|
|
} else {
|
|
/* In order to modify anything, you gotta be super-user! */
|
|
if (txc->modes && !capable(CAP_SYS_TIME))
|
|
return -EPERM;
|
|
/*
|
|
* if the quartz is off by more than 10% then
|
|
* something is VERY wrong!
|
|
*/
|
|
if (txc->modes & ADJ_TICK &&
|
|
(txc->tick < 900000/USER_HZ ||
|
|
txc->tick > 1100000/USER_HZ))
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (txc->modes & ADJ_SETOFFSET) {
|
|
/* In order to inject time, you gotta be super-user! */
|
|
if (!capable(CAP_SYS_TIME))
|
|
return -EPERM;
|
|
|
|
if (txc->modes & ADJ_NANO) {
|
|
struct timespec ts;
|
|
|
|
ts.tv_sec = txc->time.tv_sec;
|
|
ts.tv_nsec = txc->time.tv_usec;
|
|
if (!timespec_inject_offset_valid(&ts))
|
|
return -EINVAL;
|
|
|
|
} else {
|
|
if (!timeval_inject_offset_valid(&txc->time))
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check for potential multiplication overflows that can
|
|
* only happen on 64-bit systems:
|
|
*/
|
|
if ((txc->modes & ADJ_FREQUENCY) && (BITS_PER_LONG == 64)) {
|
|
if (LLONG_MIN / PPM_SCALE > txc->freq)
|
|
return -EINVAL;
|
|
if (LLONG_MAX / PPM_SCALE < txc->freq)
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* adjtimex mainly allows reading (and writing, if superuser) of
|
|
* kernel time-keeping variables. used by xntpd.
|
|
*/
|
|
int __do_adjtimex(struct timex *txc, struct timespec64 *ts, s32 *time_tai)
|
|
{
|
|
int result;
|
|
|
|
if (txc->modes & ADJ_ADJTIME) {
|
|
long save_adjust = time_adjust;
|
|
|
|
if (!(txc->modes & ADJ_OFFSET_READONLY)) {
|
|
/* adjtime() is independent from ntp_adjtime() */
|
|
time_adjust = txc->offset;
|
|
ntp_update_frequency();
|
|
}
|
|
txc->offset = save_adjust;
|
|
} else {
|
|
|
|
/* If there are input parameters, then process them: */
|
|
if (txc->modes)
|
|
process_adjtimex_modes(txc, ts, time_tai);
|
|
|
|
txc->offset = shift_right(time_offset * NTP_INTERVAL_FREQ,
|
|
NTP_SCALE_SHIFT);
|
|
if (!(time_status & STA_NANO))
|
|
txc->offset /= NSEC_PER_USEC;
|
|
}
|
|
|
|
result = time_state; /* mostly `TIME_OK' */
|
|
/* check for errors */
|
|
if (is_error_status(time_status))
|
|
result = TIME_ERROR;
|
|
|
|
txc->freq = shift_right((time_freq >> PPM_SCALE_INV_SHIFT) *
|
|
PPM_SCALE_INV, NTP_SCALE_SHIFT);
|
|
txc->maxerror = time_maxerror;
|
|
txc->esterror = time_esterror;
|
|
txc->status = time_status;
|
|
txc->constant = time_constant;
|
|
txc->precision = 1;
|
|
txc->tolerance = MAXFREQ_SCALED / PPM_SCALE;
|
|
txc->tick = tick_usec;
|
|
txc->tai = *time_tai;
|
|
|
|
/* fill PPS status fields */
|
|
pps_fill_timex(txc);
|
|
|
|
txc->time.tv_sec = (time_t)ts->tv_sec;
|
|
txc->time.tv_usec = ts->tv_nsec;
|
|
if (!(time_status & STA_NANO))
|
|
txc->time.tv_usec /= NSEC_PER_USEC;
|
|
|
|
/* Handle leapsec adjustments */
|
|
if (unlikely(ts->tv_sec >= ntp_next_leap_sec)) {
|
|
if ((time_state == TIME_INS) && (time_status & STA_INS)) {
|
|
result = TIME_OOP;
|
|
txc->tai++;
|
|
txc->time.tv_sec--;
|
|
}
|
|
if ((time_state == TIME_DEL) && (time_status & STA_DEL)) {
|
|
result = TIME_WAIT;
|
|
txc->tai--;
|
|
txc->time.tv_sec++;
|
|
}
|
|
if ((time_state == TIME_OOP) &&
|
|
(ts->tv_sec == ntp_next_leap_sec)) {
|
|
result = TIME_WAIT;
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
#ifdef CONFIG_NTP_PPS
|
|
|
|
/* actually struct pps_normtime is good old struct timespec, but it is
|
|
* semantically different (and it is the reason why it was invented):
|
|
* pps_normtime.nsec has a range of ( -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ]
|
|
* while timespec.tv_nsec has a range of [0, NSEC_PER_SEC) */
|
|
struct pps_normtime {
|
|
s64 sec; /* seconds */
|
|
long nsec; /* nanoseconds */
|
|
};
|
|
|
|
/* normalize the timestamp so that nsec is in the
|
|
( -NSEC_PER_SEC / 2, NSEC_PER_SEC / 2 ] interval */
|
|
static inline struct pps_normtime pps_normalize_ts(struct timespec64 ts)
|
|
{
|
|
struct pps_normtime norm = {
|
|
.sec = ts.tv_sec,
|
|
.nsec = ts.tv_nsec
|
|
};
|
|
|
|
if (norm.nsec > (NSEC_PER_SEC >> 1)) {
|
|
norm.nsec -= NSEC_PER_SEC;
|
|
norm.sec++;
|
|
}
|
|
|
|
return norm;
|
|
}
|
|
|
|
/* get current phase correction and jitter */
|
|
static inline long pps_phase_filter_get(long *jitter)
|
|
{
|
|
*jitter = pps_tf[0] - pps_tf[1];
|
|
if (*jitter < 0)
|
|
*jitter = -*jitter;
|
|
|
|
/* TODO: test various filters */
|
|
return pps_tf[0];
|
|
}
|
|
|
|
/* add the sample to the phase filter */
|
|
static inline void pps_phase_filter_add(long err)
|
|
{
|
|
pps_tf[2] = pps_tf[1];
|
|
pps_tf[1] = pps_tf[0];
|
|
pps_tf[0] = err;
|
|
}
|
|
|
|
/* decrease frequency calibration interval length.
|
|
* It is halved after four consecutive unstable intervals.
|
|
*/
|
|
static inline void pps_dec_freq_interval(void)
|
|
{
|
|
if (--pps_intcnt <= -PPS_INTCOUNT) {
|
|
pps_intcnt = -PPS_INTCOUNT;
|
|
if (pps_shift > PPS_INTMIN) {
|
|
pps_shift--;
|
|
pps_intcnt = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* increase frequency calibration interval length.
|
|
* It is doubled after four consecutive stable intervals.
|
|
*/
|
|
static inline void pps_inc_freq_interval(void)
|
|
{
|
|
if (++pps_intcnt >= PPS_INTCOUNT) {
|
|
pps_intcnt = PPS_INTCOUNT;
|
|
if (pps_shift < PPS_INTMAX) {
|
|
pps_shift++;
|
|
pps_intcnt = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* update clock frequency based on MONOTONIC_RAW clock PPS signal
|
|
* timestamps
|
|
*
|
|
* At the end of the calibration interval the difference between the
|
|
* first and last MONOTONIC_RAW clock timestamps divided by the length
|
|
* of the interval becomes the frequency update. If the interval was
|
|
* too long, the data are discarded.
|
|
* Returns the difference between old and new frequency values.
|
|
*/
|
|
static long hardpps_update_freq(struct pps_normtime freq_norm)
|
|
{
|
|
long delta, delta_mod;
|
|
s64 ftemp;
|
|
|
|
/* check if the frequency interval was too long */
|
|
if (freq_norm.sec > (2 << pps_shift)) {
|
|
time_status |= STA_PPSERROR;
|
|
pps_errcnt++;
|
|
pps_dec_freq_interval();
|
|
printk_deferred(KERN_ERR
|
|
"hardpps: PPSERROR: interval too long - %lld s\n",
|
|
freq_norm.sec);
|
|
return 0;
|
|
}
|
|
|
|
/* here the raw frequency offset and wander (stability) is
|
|
* calculated. If the wander is less than the wander threshold
|
|
* the interval is increased; otherwise it is decreased.
|
|
*/
|
|
ftemp = div_s64(((s64)(-freq_norm.nsec)) << NTP_SCALE_SHIFT,
|
|
freq_norm.sec);
|
|
delta = shift_right(ftemp - pps_freq, NTP_SCALE_SHIFT);
|
|
pps_freq = ftemp;
|
|
if (delta > PPS_MAXWANDER || delta < -PPS_MAXWANDER) {
|
|
printk_deferred(KERN_WARNING
|
|
"hardpps: PPSWANDER: change=%ld\n", delta);
|
|
time_status |= STA_PPSWANDER;
|
|
pps_stbcnt++;
|
|
pps_dec_freq_interval();
|
|
} else { /* good sample */
|
|
pps_inc_freq_interval();
|
|
}
|
|
|
|
/* the stability metric is calculated as the average of recent
|
|
* frequency changes, but is used only for performance
|
|
* monitoring
|
|
*/
|
|
delta_mod = delta;
|
|
if (delta_mod < 0)
|
|
delta_mod = -delta_mod;
|
|
pps_stabil += (div_s64(((s64)delta_mod) <<
|
|
(NTP_SCALE_SHIFT - SHIFT_USEC),
|
|
NSEC_PER_USEC) - pps_stabil) >> PPS_INTMIN;
|
|
|
|
/* if enabled, the system clock frequency is updated */
|
|
if ((time_status & STA_PPSFREQ) != 0 &&
|
|
(time_status & STA_FREQHOLD) == 0) {
|
|
time_freq = pps_freq;
|
|
ntp_update_frequency();
|
|
}
|
|
|
|
return delta;
|
|
}
|
|
|
|
/* correct REALTIME clock phase error against PPS signal */
|
|
static void hardpps_update_phase(long error)
|
|
{
|
|
long correction = -error;
|
|
long jitter;
|
|
|
|
/* add the sample to the median filter */
|
|
pps_phase_filter_add(correction);
|
|
correction = pps_phase_filter_get(&jitter);
|
|
|
|
/* Nominal jitter is due to PPS signal noise. If it exceeds the
|
|
* threshold, the sample is discarded; otherwise, if so enabled,
|
|
* the time offset is updated.
|
|
*/
|
|
if (jitter > (pps_jitter << PPS_POPCORN)) {
|
|
printk_deferred(KERN_WARNING
|
|
"hardpps: PPSJITTER: jitter=%ld, limit=%ld\n",
|
|
jitter, (pps_jitter << PPS_POPCORN));
|
|
time_status |= STA_PPSJITTER;
|
|
pps_jitcnt++;
|
|
} else if (time_status & STA_PPSTIME) {
|
|
/* correct the time using the phase offset */
|
|
time_offset = div_s64(((s64)correction) << NTP_SCALE_SHIFT,
|
|
NTP_INTERVAL_FREQ);
|
|
/* cancel running adjtime() */
|
|
time_adjust = 0;
|
|
}
|
|
/* update jitter */
|
|
pps_jitter += (jitter - pps_jitter) >> PPS_INTMIN;
|
|
}
|
|
|
|
/*
|
|
* __hardpps() - discipline CPU clock oscillator to external PPS signal
|
|
*
|
|
* This routine is called at each PPS signal arrival in order to
|
|
* discipline the CPU clock oscillator to the PPS signal. It takes two
|
|
* parameters: REALTIME and MONOTONIC_RAW clock timestamps. The former
|
|
* is used to correct clock phase error and the latter is used to
|
|
* correct the frequency.
|
|
*
|
|
* This code is based on David Mills's reference nanokernel
|
|
* implementation. It was mostly rewritten but keeps the same idea.
|
|
*/
|
|
void __hardpps(const struct timespec64 *phase_ts, const struct timespec64 *raw_ts)
|
|
{
|
|
struct pps_normtime pts_norm, freq_norm;
|
|
|
|
pts_norm = pps_normalize_ts(*phase_ts);
|
|
|
|
/* clear the error bits, they will be set again if needed */
|
|
time_status &= ~(STA_PPSJITTER | STA_PPSWANDER | STA_PPSERROR);
|
|
|
|
/* indicate signal presence */
|
|
time_status |= STA_PPSSIGNAL;
|
|
pps_valid = PPS_VALID;
|
|
|
|
/* when called for the first time,
|
|
* just start the frequency interval */
|
|
if (unlikely(pps_fbase.tv_sec == 0)) {
|
|
pps_fbase = *raw_ts;
|
|
return;
|
|
}
|
|
|
|
/* ok, now we have a base for frequency calculation */
|
|
freq_norm = pps_normalize_ts(timespec64_sub(*raw_ts, pps_fbase));
|
|
|
|
/* check that the signal is in the range
|
|
* [1s - MAXFREQ us, 1s + MAXFREQ us], otherwise reject it */
|
|
if ((freq_norm.sec == 0) ||
|
|
(freq_norm.nsec > MAXFREQ * freq_norm.sec) ||
|
|
(freq_norm.nsec < -MAXFREQ * freq_norm.sec)) {
|
|
time_status |= STA_PPSJITTER;
|
|
/* restart the frequency calibration interval */
|
|
pps_fbase = *raw_ts;
|
|
printk_deferred(KERN_ERR "hardpps: PPSJITTER: bad pulse\n");
|
|
return;
|
|
}
|
|
|
|
/* signal is ok */
|
|
|
|
/* check if the current frequency interval is finished */
|
|
if (freq_norm.sec >= (1 << pps_shift)) {
|
|
pps_calcnt++;
|
|
/* restart the frequency calibration interval */
|
|
pps_fbase = *raw_ts;
|
|
hardpps_update_freq(freq_norm);
|
|
}
|
|
|
|
hardpps_update_phase(pts_norm.nsec);
|
|
|
|
}
|
|
#endif /* CONFIG_NTP_PPS */
|
|
|
|
static int __init ntp_tick_adj_setup(char *str)
|
|
{
|
|
int rc = kstrtol(str, 0, (long *)&ntp_tick_adj);
|
|
|
|
if (rc)
|
|
return rc;
|
|
ntp_tick_adj <<= NTP_SCALE_SHIFT;
|
|
|
|
return 1;
|
|
}
|
|
|
|
__setup("ntp_tick_adj=", ntp_tick_adj_setup);
|
|
|
|
void __init ntp_init(void)
|
|
{
|
|
ntp_clear();
|
|
}
|