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Merge branch 'fortglx/4.5/time' of https://git.linaro.org/people/john.stultz/linux into timers/core

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Get the core time(keeping) updates from John Stultz

    - NTP robustness tweaks
    - Another signed overflow nailed down
    - More y2038 changes
    - Stop alarmtimer after resume
    - MAINTAINERS update
    - Selftest fixes
This commit is contained in:
Thomas Gleixner 2015-12-19 12:03:17 +01:00
commit e2666d6906
9 changed files with 121 additions and 28 deletions
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3
MAINTAINERS
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@ -9348,7 +9348,7 @@ M: Andreas Noever <andreas.noever@gmail.com>
S: Maintained
F: drivers/thunderbolt/
TIMEKEEPING, CLOCKSOURCE CORE, NTP
TIMEKEEPING, CLOCKSOURCE CORE, NTP, ALARMTIMER
M: John Stultz <john.stultz@linaro.org>
M: Thomas Gleixner <tglx@linutronix.de>
L: linux-kernel@vger.kernel.org
@ -9361,6 +9361,7 @@ F: include/uapi/linux/time.h
F: include/uapi/linux/timex.h
F: kernel/time/clocksource.c
F: kernel/time/time*.c
F: kernel/time/alarmtimer.c
F: kernel/time/ntp.c
F: tools/testing/selftests/timers/

26
include/linux/time.h
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@ -125,6 +125,32 @@ static inline bool timeval_valid(const struct timeval *tv)
extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
/*
* Validates if a timespec/timeval used to inject a time offset is valid.
* Offsets can be postive or negative. The value of the timeval/timespec
* is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must
* always be non-negative.
*/
static inline bool timeval_inject_offset_valid(const struct timeval *tv)
{
/* We don't check the tv_sec as it can be positive or negative */
/* Can't have more microseconds then a second */
if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
return false;
return true;
}
static inline bool timespec_inject_offset_valid(const struct timespec *ts)
{
/* We don't check the tv_sec as it can be positive or negative */
/* Can't have more nanoseconds then a second */
if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
return false;
return true;
}
#define CURRENT_TIME (current_kernel_time())
#define CURRENT_TIME_SEC ((struct timespec) { get_seconds(), 0 })

17
kernel/time/alarmtimer.c
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@ -271,11 +271,27 @@ static int alarmtimer_suspend(struct device *dev)
__pm_wakeup_event(ws, MSEC_PER_SEC);
return ret;
}
static int alarmtimer_resume(struct device *dev)
{
struct rtc_device *rtc;
rtc = alarmtimer_get_rtcdev();
if (rtc)
rtc_timer_cancel(rtc, &rtctimer);
return 0;
}
#else
static int alarmtimer_suspend(struct device *dev)
{
return 0;
}
static int alarmtimer_resume(struct device *dev)
{
return 0;
}
#endif
static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
@ -800,6 +816,7 @@ out:
/* Suspend hook structures */
static const struct dev_pm_ops alarmtimer_pm_ops = {
.suspend = alarmtimer_suspend,
.resume = alarmtimer_resume,
};
static struct platform_driver alarmtimer_driver = {

4
kernel/time/clocksource.c
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@ -218,8 +218,8 @@ static void clocksource_watchdog(unsigned long data)
/* Check the deviation from the watchdog clocksource. */
if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
pr_warn("timekeeping watchdog: Marking clocksource '%s' as unstable because the skew is too large:\n",
cs->name);
pr_warn("timekeeping watchdog on CPU%d: Marking clocksource '%s' as unstable because the skew is too large:\n",
smp_processor_id(), cs->name);
pr_warn(" '%s' wd_now: %llx wd_last: %llx mask: %llx\n",
watchdog->name, wdnow, wdlast, watchdog->mask);
pr_warn(" '%s' cs_now: %llx cs_last: %llx mask: %llx\n",

44
kernel/time/ntp.c
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@ -16,8 +16,11 @@
#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:
@ -70,7 +73,7 @@ static long time_esterror = NTP_PHASE_LIMIT;
static s64 time_freq;
/* time at last adjustment (secs): */
static long time_reftime;
static time64_t time_reftime;
static long time_adjust;
@ -297,25 +300,27 @@ static void ntp_update_offset(long offset)
if (!(time_status & STA_PLL))
return;
if (!(time_status & STA_NANO))
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 = min(offset, MAXPHASE);
offset = max(offset, -MAXPHASE);
offset = clamp(offset, -MAXPHASE, MAXPHASE);
/*
* Select how the frequency is to be controlled
* and in which mode (PLL or FLL).
*/
secs = get_seconds() - time_reftime;
secs = (long)(__ktime_get_real_seconds() - time_reftime);
if (unlikely(time_status & STA_FREQHOLD))
secs = 0;
time_reftime = get_seconds();
time_reftime = __ktime_get_real_seconds();
offset64 = offset;
freq_adj = ntp_update_offset_fll(offset64, secs);
@ -390,10 +395,11 @@ ktime_t ntp_get_next_leap(void)
*
* Also handles leap second processing, and returns leap offset
*/
int second_overflow(unsigned long secs)
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
@ -404,19 +410,19 @@ int second_overflow(unsigned long secs)
case TIME_OK:
if (time_status & STA_INS) {
time_state = TIME_INS;
ntp_next_leap_sec = secs + SECS_PER_DAY -
(secs % SECS_PER_DAY);
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;
ntp_next_leap_sec = secs + SECS_PER_DAY -
((secs+1) % SECS_PER_DAY);
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 % SECS_PER_DAY == 0) {
} else if (secs == ntp_next_leap_sec) {
leap = -1;
time_state = TIME_OOP;
printk(KERN_NOTICE
@ -427,7 +433,7 @@ int second_overflow(unsigned long secs)
if (!(time_status & STA_DEL)) {
ntp_next_leap_sec = TIME64_MAX;
time_state = TIME_OK;
} else if ((secs + 1) % SECS_PER_DAY == 0) {
} else if (secs == ntp_next_leap_sec) {
leap = 1;
ntp_next_leap_sec = TIME64_MAX;
time_state = TIME_WAIT;
@ -590,7 +596,7 @@ static inline void process_adj_status(struct timex *txc, struct timespec64 *ts)
* reference time to current time.
*/
if (!(time_status & STA_PLL) && (txc->status & STA_PLL))
time_reftime = get_seconds();
time_reftime = __ktime_get_real_seconds();
/* only set allowed bits */
time_status &= STA_RONLY;
@ -674,8 +680,14 @@ int ntp_validate_timex(struct timex *txc)
return -EINVAL;
}
if ((txc->modes & ADJ_SETOFFSET) && (!capable(CAP_SYS_TIME)))
return -EPERM;
if (txc->modes & ADJ_SETOFFSET) {
/* In order to inject time, you gotta be super-user! */
if (!capable(CAP_SYS_TIME))
return -EPERM;
if (!timeval_inject_offset_valid(&txc->time))
return -EINVAL;
}
/*
* Check for potential multiplication overflows that can

2
kernel/time/ntp_internal.h
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@ -6,7 +6,7 @@ extern void ntp_clear(void);
/* Returns how long ticks are at present, in ns / 2^NTP_SCALE_SHIFT. */
extern u64 ntp_tick_length(void);
extern ktime_t ntp_get_next_leap(void);
extern int second_overflow(unsigned long secs);
extern int second_overflow(time64_t secs);
extern int ntp_validate_timex(struct timex *);
extern int __do_adjtimex(struct timex *, struct timespec64 *, s32 *);
extern void __hardpps(const struct timespec64 *, const struct timespec64 *);

49
kernel/time/timekeeping.c
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@ -305,8 +305,7 @@ static inline s64 timekeeping_get_ns(struct tk_read_base *tkr)
delta = timekeeping_get_delta(tkr);
nsec = delta * tkr->mult + tkr->xtime_nsec;
nsec >>= tkr->shift;
nsec = (delta * tkr->mult + tkr->xtime_nsec) >> tkr->shift;
/* If arch requires, add in get_arch_timeoffset() */
return nsec + arch_gettimeoffset();
@ -846,6 +845,19 @@ time64_t ktime_get_real_seconds(void)
}
EXPORT_SYMBOL_GPL(ktime_get_real_seconds);
/**
* __ktime_get_real_seconds - The same as ktime_get_real_seconds
* but without the sequence counter protect. This internal function
* is called just when timekeeping lock is already held.
*/
time64_t __ktime_get_real_seconds(void)
{
struct timekeeper *tk = &tk_core.timekeeper;
return tk->xtime_sec;
}
#ifdef CONFIG_NTP_PPS
/**
@ -959,7 +971,7 @@ int timekeeping_inject_offset(struct timespec *ts)
struct timespec64 ts64, tmp;
int ret = 0;
if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
if (!timespec_inject_offset_valid(ts))
return -EINVAL;
ts64 = timespec_to_timespec64(*ts);
@ -1592,9 +1604,12 @@ static __always_inline void timekeeping_freqadjust(struct timekeeper *tk,
{
s64 interval = tk->cycle_interval;
s64 xinterval = tk->xtime_interval;
u32 base = tk->tkr_mono.clock->mult;
u32 max = tk->tkr_mono.clock->maxadj;
u32 cur_adj = tk->tkr_mono.mult;
s64 tick_error;
bool negative;
u32 adj;
u32 adj_scale;
/* Remove any current error adj from freq calculation */
if (tk->ntp_err_mult)
@ -1613,13 +1628,33 @@ static __always_inline void timekeeping_freqadjust(struct timekeeper *tk,
/* preserve the direction of correction */
negative = (tick_error < 0);
/* Sort out the magnitude of the correction */
/* If any adjustment would pass the max, just return */
if (negative && (cur_adj - 1) <= (base - max))
return;
if (!negative && (cur_adj + 1) >= (base + max))
return;
/*
* Sort out the magnitude of the correction, but
* avoid making so large a correction that we go
* over the max adjustment.
*/
adj_scale = 0;
tick_error = abs(tick_error);
for (adj = 0; tick_error > interval; adj++)
while (tick_error > interval) {
u32 adj = 1 << (adj_scale + 1);
/* Check if adjustment gets us within 1 unit from the max */
if (negative && (cur_adj - adj) <= (base - max))
break;
if (!negative && (cur_adj + adj) >= (base + max))
break;
adj_scale++;
tick_error >>= 1;
}
/* scale the corrections */
timekeeping_apply_adjustment(tk, offset, negative, adj);
timekeeping_apply_adjustment(tk, offset, negative, adj_scale);
}
/*

2
kernel/time/timekeeping_internal.h
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@ -26,4 +26,6 @@ static inline cycle_t clocksource_delta(cycle_t now, cycle_t last, cycle_t mask)
}
#endif
extern time64_t __ktime_get_real_seconds(void);
#endif /* _TIMEKEEPING_INTERNAL_H */

2
tools/testing/selftests/timers/clocksource-switch.c
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@ -97,7 +97,7 @@ int get_cur_clocksource(char *buf, size_t size)
int change_clocksource(char *clocksource)
{
int fd;
size_t size;
ssize_t size;
fd = open("/sys/devices/system/clocksource/clocksource0/current_clocksource", O_WRONLY);