* "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/errno.h>
#include <linux/smp_lock.h>
+#include <linux/syscalls.h>
+#include <linux/security.h>
+#include <linux/fs.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)
{
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;
+
+ 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;
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;
+}
+
+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);
+ {
+ /*
+ * This is revolting. We need to set "xtime" correctly. However, the value
+ * in this location is the value at the most recent update of wall time.
+ * Discover what correction gettimeofday would have done, and then undo
+ * it!
+ */
+ nsec -= time_interpolator_get_offset();
+
+ 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;
+}
+
+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;
+}
+#endif
+
#if (BITS_PER_LONG < 64)
u64 get_jiffies_64(void)
{
git://git.onelab.eu / linux-2.6.git / blobdiff