* "A Kernel Model for Precision Timekeeping" by Dave Mills
* Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10)
* (Even though the technical memorandum forbids it)
+ * 2004-07-14 Christoph Lameter
+ * Added getnstimeofday to allow the posix timer functions to return
+ * with nanosecond accuracy
*/
#include <linux/module.h>
#include <linux/timex.h>
+#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
+#include <linux/syscalls.h>
+#include <linux/security.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+
#include <asm/uaccess.h>
+#include <asm/unistd.h>
/*
* The timezone where the local system is located. Used as a default by some
EXPORT_SYMBOL(sys_tz);
-#if !defined(__alpha__) && !defined(__ia64__)
+#ifdef __ARCH_WANT_SYS_TIME
/*
* sys_time() can be implemented in user-level using
* sys_gettimeofday(). Is this for backwards compatibility? If so,
* why not move it into the appropriate arch directory (for those
* architectures that need it).
- *
- * XXX This function is NOT 64-bit clean!
*/
-asmlinkage long sys_time(int * tloc)
+asmlinkage long sys_time(time_t __user * tloc)
{
- int i;
+ time_t i;
struct timeval tv;
do_gettimeofday(&tv);
* architectures that need it).
*/
-asmlinkage long sys_stime(time_t *tptr)
+asmlinkage long sys_stime(time_t __user *tptr)
{
struct timespec tv;
+ int err;
- if (!capable(CAP_SYS_TIME))
- return -EPERM;
if (get_user(tv.tv_sec, tptr))
return -EFAULT;
tv.tv_nsec = 0;
+
+ err = security_settime(&tv, NULL);
+ if (err)
+ return err;
+
do_settimeofday(&tv);
return 0;
}
-#endif
+#endif /* __ARCH_WANT_SYS_TIME */
asmlinkage long sys_gettimeofday(struct timeval __user *tv, struct timezone __user *tz)
{
* as real UNIX machines always do it. This avoids all headaches about
* daylight saving times and warping kernel clocks.
*/
-inline static void warp_clock(void)
+static inline void warp_clock(void)
{
write_seqlock_irq(&xtime_lock);
wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60;
xtime.tv_sec += sys_tz.tz_minuteswest * 60;
- time_interpolator_update(sys_tz.tz_minuteswest * 60 * NSEC_PER_SEC);
+ time_interpolator_reset();
write_sequnlock_irq(&xtime_lock);
clock_was_set();
}
int do_sys_settimeofday(struct timespec *tv, struct timezone *tz)
{
static int firsttime = 1;
+ int error = 0;
+
+ if (tv && !timespec_valid(tv))
+ return -EINVAL;
+
+ error = security_settime(tv, tz);
+ if (error)
+ return error;
- if (!capable(CAP_SYS_TIME))
- return -EPERM;
-
if (tz) {
/* SMP safe, global irq locking makes it work. */
sys_tz = *tz;
/* hook for a loadable hardpps kernel module */
void (*hardpps_ptr)(struct timeval *);
+/* we call this to notify the arch when the clock is being
+ * controlled. If no such arch routine, do nothing.
+ */
+void __attribute__ ((weak)) notify_arch_cmos_timer(void)
+{
+ return;
+}
+
/* adjtimex mainly allows reading (and writing, if superuser) of
* kernel time-keeping variables. used by xntpd.
*/
if (mtemp >= MINSEC) {
ltemp = (time_offset / mtemp) << (SHIFT_USEC -
SHIFT_UPDATE);
- if (ltemp < 0)
- time_freq -= -ltemp >> SHIFT_KH;
- else
- time_freq += ltemp >> SHIFT_KH;
+ time_freq += shift_right(ltemp, SHIFT_KH);
} else /* calibration interval too short (p. 12) */
result = TIME_ERROR;
} else { /* PLL mode */
if (mtemp < MAXSEC) {
ltemp *= mtemp;
- if (ltemp < 0)
- time_freq -= -ltemp >> (time_constant +
- time_constant +
- SHIFT_KF - SHIFT_USEC);
- else
- time_freq += ltemp >> (time_constant +
+ time_freq += shift_right(ltemp,(time_constant +
time_constant +
- SHIFT_KF - SHIFT_USEC);
+ SHIFT_KF - SHIFT_USEC));
} else /* calibration interval too long (p. 12) */
result = TIME_ERROR;
}
- if (time_freq > time_tolerance)
- time_freq = time_tolerance;
- else if (time_freq < -time_tolerance)
- time_freq = -time_tolerance;
+ time_freq = min(time_freq, time_tolerance);
+ time_freq = max(time_freq, -time_tolerance);
} /* STA_PLL || STA_PPSTIME */
} /* txc->modes & ADJ_OFFSET */
if (txc->modes & ADJ_TICK) {
if ((txc->modes & ADJ_OFFSET_SINGLESHOT) == ADJ_OFFSET_SINGLESHOT)
txc->offset = save_adjust;
else {
- if (time_offset < 0)
- txc->offset = -(-time_offset >> SHIFT_UPDATE);
- else
- txc->offset = time_offset >> SHIFT_UPDATE;
+ txc->offset = shift_right(time_offset, SHIFT_UPDATE);
}
txc->freq = time_freq + pps_freq;
txc->maxerror = time_maxerror;
txc->stbcnt = pps_stbcnt;
write_sequnlock_irq(&xtime_lock);
do_gettimeofday(&txc->time);
+ notify_arch_cmos_timer();
return(result);
}
return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
}
-struct timespec current_kernel_time(void)
+inline struct timespec current_kernel_time(void)
{
struct timespec now;
unsigned long seq;
EXPORT_SYMBOL(current_kernel_time);
+/**
+ * current_fs_time - Return FS time
+ * @sb: Superblock.
+ *
+ * Return the current time truncated to the time granuality supported by
+ * the fs.
+ */
+struct timespec current_fs_time(struct super_block *sb)
+{
+ struct timespec now = current_kernel_time();
+ return timespec_trunc(now, sb->s_time_gran);
+}
+EXPORT_SYMBOL(current_fs_time);
+
+/**
+ * timespec_trunc - Truncate timespec to a granuality
+ * @t: Timespec
+ * @gran: Granuality in ns.
+ *
+ * Truncate a timespec to a granuality. gran must be smaller than a second.
+ * Always rounds down.
+ *
+ * This function should be only used for timestamps returned by
+ * current_kernel_time() or CURRENT_TIME, not with do_gettimeofday() because
+ * it doesn't handle the better resolution of the later.
+ */
+struct timespec timespec_trunc(struct timespec t, unsigned gran)
+{
+ /*
+ * Division is pretty slow so avoid it for common cases.
+ * Currently current_kernel_time() never returns better than
+ * jiffies resolution. Exploit that.
+ */
+ if (gran <= jiffies_to_usecs(1) * 1000) {
+ /* nothing */
+ } else if (gran == 1000000000) {
+ t.tv_nsec = 0;
+ } else {
+ t.tv_nsec -= t.tv_nsec % gran;
+ }
+ return t;
+}
+EXPORT_SYMBOL(timespec_trunc);
+
+#ifdef CONFIG_TIME_INTERPOLATION
+void getnstimeofday (struct timespec *tv)
+{
+ unsigned long seq,sec,nsec;
+
+ do {
+ seq = read_seqbegin(&xtime_lock);
+ sec = xtime.tv_sec;
+ nsec = xtime.tv_nsec+time_interpolator_get_offset();
+ } while (unlikely(read_seqretry(&xtime_lock, seq)));
+
+ while (unlikely(nsec >= NSEC_PER_SEC)) {
+ nsec -= NSEC_PER_SEC;
+ ++sec;
+ }
+ tv->tv_sec = sec;
+ tv->tv_nsec = nsec;
+}
+EXPORT_SYMBOL_GPL(getnstimeofday);
+
+int do_settimeofday (struct timespec *tv)
+{
+ time_t wtm_sec, sec = tv->tv_sec;
+ long wtm_nsec, nsec = tv->tv_nsec;
+
+ if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+ return -EINVAL;
+
+ write_seqlock_irq(&xtime_lock);
+ {
+ wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
+ wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
+
+ set_normalized_timespec(&xtime, sec, nsec);
+ set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
+
+ time_adjust = 0; /* stop active adjtime() */
+ time_status |= STA_UNSYNC;
+ time_maxerror = NTP_PHASE_LIMIT;
+ time_esterror = NTP_PHASE_LIMIT;
+ time_interpolator_reset();
+ }
+ write_sequnlock_irq(&xtime_lock);
+ clock_was_set();
+ return 0;
+}
+EXPORT_SYMBOL(do_settimeofday);
+
+void do_gettimeofday (struct timeval *tv)
+{
+ unsigned long seq, nsec, usec, sec, offset;
+ do {
+ seq = read_seqbegin(&xtime_lock);
+ offset = time_interpolator_get_offset();
+ sec = xtime.tv_sec;
+ nsec = xtime.tv_nsec;
+ } while (unlikely(read_seqretry(&xtime_lock, seq)));
+
+ usec = (nsec + offset) / 1000;
+
+ while (unlikely(usec >= USEC_PER_SEC)) {
+ usec -= USEC_PER_SEC;
+ ++sec;
+ }
+
+ tv->tv_sec = sec;
+ tv->tv_usec = usec;
+}
+
+EXPORT_SYMBOL(do_gettimeofday);
+
+
+#else
+/*
+ * Simulate gettimeofday using do_gettimeofday which only allows a timeval
+ * and therefore only yields usec accuracy
+ */
+void getnstimeofday(struct timespec *tv)
+{
+ struct timeval x;
+
+ do_gettimeofday(&x);
+ tv->tv_sec = x.tv_sec;
+ tv->tv_nsec = x.tv_usec * NSEC_PER_USEC;
+}
+EXPORT_SYMBOL_GPL(getnstimeofday);
+#endif
+
+/* Converts Gregorian date to seconds since 1970-01-01 00:00:00.
+ * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
+ * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
+ *
+ * [For the Julian calendar (which was used in Russia before 1917,
+ * Britain & colonies before 1752, anywhere else before 1582,
+ * and is still in use by some communities) leave out the
+ * -year/100+year/400 terms, and add 10.]
+ *
+ * This algorithm was first published by Gauss (I think).
+ *
+ * WARNING: this function will overflow on 2106-02-07 06:28:16 on
+ * machines were long is 32-bit! (However, as time_t is signed, we
+ * will already get problems at other places on 2038-01-19 03:14:08)
+ */
+unsigned long
+mktime(const unsigned int year0, const unsigned int mon0,
+ const unsigned int day, const unsigned int hour,
+ const unsigned int min, const unsigned int sec)
+{
+ unsigned int mon = mon0, year = year0;
+
+ /* 1..12 -> 11,12,1..10 */
+ if (0 >= (int) (mon -= 2)) {
+ mon += 12; /* Puts Feb last since it has leap day */
+ year -= 1;
+ }
+
+ return ((((unsigned long)
+ (year/4 - year/100 + year/400 + 367*mon/12 + day) +
+ year*365 - 719499
+ )*24 + hour /* now have hours */
+ )*60 + min /* now have minutes */
+ )*60 + sec; /* finally seconds */
+}
+
+EXPORT_SYMBOL(mktime);
+
+/**
+ * set_normalized_timespec - set timespec sec and nsec parts and normalize
+ *
+ * @ts: pointer to timespec variable to be set
+ * @sec: seconds to set
+ * @nsec: nanoseconds to set
+ *
+ * Set seconds and nanoseconds field of a timespec variable and
+ * normalize to the timespec storage format
+ *
+ * Note: The tv_nsec part is always in the range of
+ * 0 <= tv_nsec < NSEC_PER_SEC
+ * For negative values only the tv_sec field is negative !
+ */
+void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec)
+{
+ while (nsec >= NSEC_PER_SEC) {
+ nsec -= NSEC_PER_SEC;
+ ++sec;
+ }
+ while (nsec < 0) {
+ nsec += NSEC_PER_SEC;
+ --sec;
+ }
+ ts->tv_sec = sec;
+ ts->tv_nsec = nsec;
+}
+
+/**
+ * ns_to_timespec - Convert nanoseconds to timespec
+ * @nsec: the nanoseconds value to be converted
+ *
+ * Returns the timespec representation of the nsec parameter.
+ */
+struct timespec ns_to_timespec(const nsec_t nsec)
+{
+ struct timespec ts;
+
+ if (!nsec)
+ return (struct timespec) {0, 0};
+
+ ts.tv_sec = div_long_long_rem_signed(nsec, NSEC_PER_SEC, &ts.tv_nsec);
+ if (unlikely(nsec < 0))
+ set_normalized_timespec(&ts, ts.tv_sec, ts.tv_nsec);
+
+ return ts;
+}
+
+/**
+ * ns_to_timeval - Convert nanoseconds to timeval
+ * @nsec: the nanoseconds value to be converted
+ *
+ * Returns the timeval representation of the nsec parameter.
+ */
+struct timeval ns_to_timeval(const nsec_t nsec)
+{
+ struct timespec ts = ns_to_timespec(nsec);
+ struct timeval tv;
+
+ tv.tv_sec = ts.tv_sec;
+ tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000;
+
+ return tv;
+}
+
#if (BITS_PER_LONG < 64)
u64 get_jiffies_64(void)
{