1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1991, 1992 Linus Torvalds
5 * This file contains the interface functions for the various time related
6 * system calls: time, stime, gettimeofday, settimeofday, adjtime
8 * Modification history:
10 * 1993-09-02 Philip Gladstone
11 * Created file with time related functions from sched/core.c and adjtimex()
12 * 1993-10-08 Torsten Duwe
13 * adjtime interface update and CMOS clock write code
14 * 1995-08-13 Torsten Duwe
15 * kernel PLL updated to 1994-12-13 specs (rfc-1589)
16 * 1999-01-16 Ulrich Windl
17 * Introduced error checking for many cases in adjtimex().
18 * Updated NTP code according to technical memorandum Jan '96
19 * "A Kernel Model for Precision Timekeeping" by Dave Mills
20 * Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10)
21 * (Even though the technical memorandum forbids it)
22 * 2004-07-14 Christoph Lameter
23 * Added getnstimeofday to allow the posix timer functions to return
24 * with nanosecond accuracy
27 #include <linux/export.h>
28 #include <linux/kernel.h>
29 #include <linux/timex.h>
30 #include <linux/capability.h>
31 #include <linux/timekeeper_internal.h>
32 #include <linux/errno.h>
33 #include <linux/syscalls.h>
34 #include <linux/security.h>
36 #include <linux/math64.h>
37 #include <linux/ptrace.h>
39 #include <linux/uaccess.h>
40 #include <linux/compat.h>
41 #include <asm/unistd.h>
43 #include <generated/timeconst.h>
44 #include "timekeeping.h"
47 * The timezone where the local system is located. Used as a default by some
48 * programs who obtain this value by using gettimeofday.
50 struct timezone sys_tz;
52 EXPORT_SYMBOL(sys_tz);
54 #ifdef __ARCH_WANT_SYS_TIME
57 * sys_time() can be implemented in user-level using
58 * sys_gettimeofday(). Is this for backwards compatibility? If so,
59 * why not move it into the appropriate arch directory (for those
60 * architectures that need it).
62 SYSCALL_DEFINE1(time, time_t __user *, tloc)
64 time_t i = (time_t)ktime_get_real_seconds();
70 force_successful_syscall_return();
75 * sys_stime() can be implemented in user-level using
76 * sys_settimeofday(). Is this for backwards compatibility? If so,
77 * why not move it into the appropriate arch directory (for those
78 * architectures that need it).
81 SYSCALL_DEFINE1(stime, time_t __user *, tptr)
86 if (get_user(tv.tv_sec, tptr))
91 err = security_settime64(&tv, NULL);
95 do_settimeofday64(&tv);
99 #endif /* __ARCH_WANT_SYS_TIME */
101 #ifdef CONFIG_COMPAT_32BIT_TIME
102 #ifdef __ARCH_WANT_SYS_TIME32
104 /* old_time32_t is a 32 bit "long" and needs to get converted. */
105 SYSCALL_DEFINE1(time32, old_time32_t __user *, tloc)
109 i = (old_time32_t)ktime_get_real_seconds();
112 if (put_user(i,tloc))
115 force_successful_syscall_return();
119 SYSCALL_DEFINE1(stime32, old_time32_t __user *, tptr)
121 struct timespec64 tv;
124 if (get_user(tv.tv_sec, tptr))
129 err = security_settime64(&tv, NULL);
133 do_settimeofday64(&tv);
137 #endif /* __ARCH_WANT_SYS_TIME32 */
140 SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv,
141 struct timezone __user *, tz)
143 if (likely(tv != NULL)) {
144 struct timespec64 ts;
146 ktime_get_real_ts64(&ts);
147 if (put_user(ts.tv_sec, &tv->tv_sec) ||
148 put_user(ts.tv_nsec / 1000, &tv->tv_usec))
151 if (unlikely(tz != NULL)) {
152 if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
159 * In case for some reason the CMOS clock has not already been running
160 * in UTC, but in some local time: The first time we set the timezone,
161 * we will warp the clock so that it is ticking UTC time instead of
162 * local time. Presumably, if someone is setting the timezone then we
163 * are running in an environment where the programs understand about
164 * timezones. This should be done at boot time in the /etc/rc script,
165 * as soon as possible, so that the clock can be set right. Otherwise,
166 * various programs will get confused when the clock gets warped.
169 int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz)
171 static int firsttime = 1;
174 if (tv && !timespec64_valid_settod(tv))
177 error = security_settime64(tv, tz);
182 /* Verify we're witin the +-15 hrs range */
183 if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60)
187 update_vsyscall_tz();
191 timekeeping_warp_clock();
195 return do_settimeofday64(tv);
199 SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv,
200 struct timezone __user *, tz)
202 struct timespec64 new_ts;
203 struct timeval user_tv;
204 struct timezone new_tz;
207 if (copy_from_user(&user_tv, tv, sizeof(*tv)))
210 if (!timeval_valid(&user_tv))
213 new_ts.tv_sec = user_tv.tv_sec;
214 new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
217 if (copy_from_user(&new_tz, tz, sizeof(*tz)))
221 return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL);
225 COMPAT_SYSCALL_DEFINE2(gettimeofday, struct old_timeval32 __user *, tv,
226 struct timezone __user *, tz)
229 struct timespec64 ts;
231 ktime_get_real_ts64(&ts);
232 if (put_user(ts.tv_sec, &tv->tv_sec) ||
233 put_user(ts.tv_nsec / 1000, &tv->tv_usec))
237 if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
244 COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv,
245 struct timezone __user *, tz)
247 struct timespec64 new_ts;
248 struct timeval user_tv;
249 struct timezone new_tz;
252 if (compat_get_timeval(&user_tv, tv))
255 if (!timeval_valid(&user_tv))
258 new_ts.tv_sec = user_tv.tv_sec;
259 new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
262 if (copy_from_user(&new_tz, tz, sizeof(*tz)))
266 return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL);
270 #if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
271 SYSCALL_DEFINE1(adjtimex, struct __kernel_timex __user *, txc_p)
273 struct __kernel_timex txc; /* Local copy of parameter */
276 /* Copy the user data space into the kernel copy
277 * structure. But bear in mind that the structures
280 if (copy_from_user(&txc, txc_p, sizeof(struct __kernel_timex)))
282 ret = do_adjtimex(&txc);
283 return copy_to_user(txc_p, &txc, sizeof(struct __kernel_timex)) ? -EFAULT : ret;
287 #ifdef CONFIG_COMPAT_32BIT_TIME
288 int get_old_timex32(struct __kernel_timex *txc, const struct old_timex32 __user *utp)
290 struct old_timex32 tx32;
292 memset(txc, 0, sizeof(struct __kernel_timex));
293 if (copy_from_user(&tx32, utp, sizeof(struct old_timex32)))
296 txc->modes = tx32.modes;
297 txc->offset = tx32.offset;
298 txc->freq = tx32.freq;
299 txc->maxerror = tx32.maxerror;
300 txc->esterror = tx32.esterror;
301 txc->status = tx32.status;
302 txc->constant = tx32.constant;
303 txc->precision = tx32.precision;
304 txc->tolerance = tx32.tolerance;
305 txc->time.tv_sec = tx32.time.tv_sec;
306 txc->time.tv_usec = tx32.time.tv_usec;
307 txc->tick = tx32.tick;
308 txc->ppsfreq = tx32.ppsfreq;
309 txc->jitter = tx32.jitter;
310 txc->shift = tx32.shift;
311 txc->stabil = tx32.stabil;
312 txc->jitcnt = tx32.jitcnt;
313 txc->calcnt = tx32.calcnt;
314 txc->errcnt = tx32.errcnt;
315 txc->stbcnt = tx32.stbcnt;
320 int put_old_timex32(struct old_timex32 __user *utp, const struct __kernel_timex *txc)
322 struct old_timex32 tx32;
324 memset(&tx32, 0, sizeof(struct old_timex32));
325 tx32.modes = txc->modes;
326 tx32.offset = txc->offset;
327 tx32.freq = txc->freq;
328 tx32.maxerror = txc->maxerror;
329 tx32.esterror = txc->esterror;
330 tx32.status = txc->status;
331 tx32.constant = txc->constant;
332 tx32.precision = txc->precision;
333 tx32.tolerance = txc->tolerance;
334 tx32.time.tv_sec = txc->time.tv_sec;
335 tx32.time.tv_usec = txc->time.tv_usec;
336 tx32.tick = txc->tick;
337 tx32.ppsfreq = txc->ppsfreq;
338 tx32.jitter = txc->jitter;
339 tx32.shift = txc->shift;
340 tx32.stabil = txc->stabil;
341 tx32.jitcnt = txc->jitcnt;
342 tx32.calcnt = txc->calcnt;
343 tx32.errcnt = txc->errcnt;
344 tx32.stbcnt = txc->stbcnt;
346 if (copy_to_user(utp, &tx32, sizeof(struct old_timex32)))
351 SYSCALL_DEFINE1(adjtimex_time32, struct old_timex32 __user *, utp)
353 struct __kernel_timex txc;
356 err = get_old_timex32(&txc, utp);
360 ret = do_adjtimex(&txc);
362 err = put_old_timex32(utp, &txc);
371 * Convert jiffies to milliseconds and back.
373 * Avoid unnecessary multiplications/divisions in the
374 * two most common HZ cases:
376 unsigned int jiffies_to_msecs(const unsigned long j)
378 #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
379 return (MSEC_PER_SEC / HZ) * j;
380 #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC)
381 return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC);
383 # if BITS_PER_LONG == 32
384 return (HZ_TO_MSEC_MUL32 * j + (1ULL << HZ_TO_MSEC_SHR32) - 1) >>
387 return DIV_ROUND_UP(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN);
391 EXPORT_SYMBOL(jiffies_to_msecs);
393 unsigned int jiffies_to_usecs(const unsigned long j)
396 * Hz usually doesn't go much further MSEC_PER_SEC.
397 * jiffies_to_usecs() and usecs_to_jiffies() depend on that.
399 BUILD_BUG_ON(HZ > USEC_PER_SEC);
401 #if !(USEC_PER_SEC % HZ)
402 return (USEC_PER_SEC / HZ) * j;
404 # if BITS_PER_LONG == 32
405 return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32;
407 return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN;
411 EXPORT_SYMBOL(jiffies_to_usecs);
414 * mktime64 - Converts date to seconds.
415 * Converts Gregorian date to seconds since 1970-01-01 00:00:00.
416 * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
417 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
419 * [For the Julian calendar (which was used in Russia before 1917,
420 * Britain & colonies before 1752, anywhere else before 1582,
421 * and is still in use by some communities) leave out the
422 * -year/100+year/400 terms, and add 10.]
424 * This algorithm was first published by Gauss (I think).
426 * A leap second can be indicated by calling this function with sec as
427 * 60 (allowable under ISO 8601). The leap second is treated the same
428 * as the following second since they don't exist in UNIX time.
430 * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight
431 * tomorrow - (allowable under ISO 8601) is supported.
433 time64_t mktime64(const unsigned int year0, const unsigned int mon0,
434 const unsigned int day, const unsigned int hour,
435 const unsigned int min, const unsigned int sec)
437 unsigned int mon = mon0, year = year0;
439 /* 1..12 -> 11,12,1..10 */
440 if (0 >= (int) (mon -= 2)) {
441 mon += 12; /* Puts Feb last since it has leap day */
446 (year/4 - year/100 + year/400 + 367*mon/12 + day) +
448 )*24 + hour /* now have hours - midnight tomorrow handled here */
449 )*60 + min /* now have minutes */
450 )*60 + sec; /* finally seconds */
452 EXPORT_SYMBOL(mktime64);
455 * ns_to_timespec - Convert nanoseconds to timespec
456 * @nsec: the nanoseconds value to be converted
458 * Returns the timespec representation of the nsec parameter.
460 struct timespec ns_to_timespec(const s64 nsec)
466 return (struct timespec) {0, 0};
468 ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);
469 if (unlikely(rem < 0)) {
477 EXPORT_SYMBOL(ns_to_timespec);
480 * ns_to_timeval - Convert nanoseconds to timeval
481 * @nsec: the nanoseconds value to be converted
483 * Returns the timeval representation of the nsec parameter.
485 struct timeval ns_to_timeval(const s64 nsec)
487 struct timespec ts = ns_to_timespec(nsec);
490 tv.tv_sec = ts.tv_sec;
491 tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000;
495 EXPORT_SYMBOL(ns_to_timeval);
497 struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec)
499 struct timespec64 ts = ns_to_timespec64(nsec);
500 struct __kernel_old_timeval tv;
502 tv.tv_sec = ts.tv_sec;
503 tv.tv_usec = (suseconds_t)ts.tv_nsec / 1000;
507 EXPORT_SYMBOL(ns_to_kernel_old_timeval);
510 * set_normalized_timespec - set timespec sec and nsec parts and normalize
512 * @ts: pointer to timespec variable to be set
513 * @sec: seconds to set
514 * @nsec: nanoseconds to set
516 * Set seconds and nanoseconds field of a timespec variable and
517 * normalize to the timespec storage format
519 * Note: The tv_nsec part is always in the range of
520 * 0 <= tv_nsec < NSEC_PER_SEC
521 * For negative values only the tv_sec field is negative !
523 void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec)
525 while (nsec >= NSEC_PER_SEC) {
527 * The following asm() prevents the compiler from
528 * optimising this loop into a modulo operation. See
529 * also __iter_div_u64_rem() in include/linux/time.h
531 asm("" : "+rm"(nsec));
532 nsec -= NSEC_PER_SEC;
536 asm("" : "+rm"(nsec));
537 nsec += NSEC_PER_SEC;
543 EXPORT_SYMBOL(set_normalized_timespec64);
546 * ns_to_timespec64 - Convert nanoseconds to timespec64
547 * @nsec: the nanoseconds value to be converted
549 * Returns the timespec64 representation of the nsec parameter.
551 struct timespec64 ns_to_timespec64(const s64 nsec)
553 struct timespec64 ts;
557 return (struct timespec64) {0, 0};
559 ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem);
560 if (unlikely(rem < 0)) {
568 EXPORT_SYMBOL(ns_to_timespec64);
571 * msecs_to_jiffies: - convert milliseconds to jiffies
572 * @m: time in milliseconds
574 * conversion is done as follows:
576 * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)
578 * - 'too large' values [that would result in larger than
579 * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too.
581 * - all other values are converted to jiffies by either multiplying
582 * the input value by a factor or dividing it with a factor and
583 * handling any 32-bit overflows.
584 * for the details see __msecs_to_jiffies()
586 * msecs_to_jiffies() checks for the passed in value being a constant
587 * via __builtin_constant_p() allowing gcc to eliminate most of the
588 * code, __msecs_to_jiffies() is called if the value passed does not
589 * allow constant folding and the actual conversion must be done at
591 * the _msecs_to_jiffies helpers are the HZ dependent conversion
592 * routines found in include/linux/jiffies.h
594 unsigned long __msecs_to_jiffies(const unsigned int m)
597 * Negative value, means infinite timeout:
600 return MAX_JIFFY_OFFSET;
601 return _msecs_to_jiffies(m);
603 EXPORT_SYMBOL(__msecs_to_jiffies);
605 unsigned long __usecs_to_jiffies(const unsigned int u)
607 if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
608 return MAX_JIFFY_OFFSET;
609 return _usecs_to_jiffies(u);
611 EXPORT_SYMBOL(__usecs_to_jiffies);
614 * The TICK_NSEC - 1 rounds up the value to the next resolution. Note
615 * that a remainder subtract here would not do the right thing as the
616 * resolution values don't fall on second boundries. I.e. the line:
617 * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding.
618 * Note that due to the small error in the multiplier here, this
619 * rounding is incorrect for sufficiently large values of tv_nsec, but
620 * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're
623 * Rather, we just shift the bits off the right.
625 * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec
626 * value to a scaled second value.
629 __timespec64_to_jiffies(u64 sec, long nsec)
631 nsec = nsec + TICK_NSEC - 1;
633 if (sec >= MAX_SEC_IN_JIFFIES){
634 sec = MAX_SEC_IN_JIFFIES;
637 return ((sec * SEC_CONVERSION) +
638 (((u64)nsec * NSEC_CONVERSION) >>
639 (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
644 __timespec_to_jiffies(unsigned long sec, long nsec)
646 return __timespec64_to_jiffies((u64)sec, nsec);
650 timespec64_to_jiffies(const struct timespec64 *value)
652 return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec);
654 EXPORT_SYMBOL(timespec64_to_jiffies);
657 jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value)
660 * Convert jiffies to nanoseconds and separate with
664 value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
666 value->tv_nsec = rem;
668 EXPORT_SYMBOL(jiffies_to_timespec64);
671 * We could use a similar algorithm to timespec_to_jiffies (with a
672 * different multiplier for usec instead of nsec). But this has a
673 * problem with rounding: we can't exactly add TICK_NSEC - 1 to the
674 * usec value, since it's not necessarily integral.
676 * We could instead round in the intermediate scaled representation
677 * (i.e. in units of 1/2^(large scale) jiffies) but that's also
678 * perilous: the scaling introduces a small positive error, which
679 * combined with a division-rounding-upward (i.e. adding 2^(scale) - 1
680 * units to the intermediate before shifting) leads to accidental
681 * overflow and overestimates.
683 * At the cost of one additional multiplication by a constant, just
684 * use the timespec implementation.
687 timeval_to_jiffies(const struct timeval *value)
689 return __timespec_to_jiffies(value->tv_sec,
690 value->tv_usec * NSEC_PER_USEC);
692 EXPORT_SYMBOL(timeval_to_jiffies);
694 void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value)
697 * Convert jiffies to nanoseconds and separate with
702 value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
704 value->tv_usec = rem / NSEC_PER_USEC;
706 EXPORT_SYMBOL(jiffies_to_timeval);
709 * Convert jiffies/jiffies_64 to clock_t and back.
711 clock_t jiffies_to_clock_t(unsigned long x)
713 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
715 return x * (USER_HZ / HZ);
717 return x / (HZ / USER_HZ);
720 return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ);
723 EXPORT_SYMBOL(jiffies_to_clock_t);
725 unsigned long clock_t_to_jiffies(unsigned long x)
727 #if (HZ % USER_HZ)==0
728 if (x >= ~0UL / (HZ / USER_HZ))
730 return x * (HZ / USER_HZ);
732 /* Don't worry about loss of precision here .. */
733 if (x >= ~0UL / HZ * USER_HZ)
736 /* .. but do try to contain it here */
737 return div_u64((u64)x * HZ, USER_HZ);
740 EXPORT_SYMBOL(clock_t_to_jiffies);
742 u64 jiffies_64_to_clock_t(u64 x)
744 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
746 x = div_u64(x * USER_HZ, HZ);
748 x = div_u64(x, HZ / USER_HZ);
754 * There are better ways that don't overflow early,
755 * but even this doesn't overflow in hundreds of years
758 x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ));
762 EXPORT_SYMBOL(jiffies_64_to_clock_t);
764 u64 nsec_to_clock_t(u64 x)
766 #if (NSEC_PER_SEC % USER_HZ) == 0
767 return div_u64(x, NSEC_PER_SEC / USER_HZ);
768 #elif (USER_HZ % 512) == 0
769 return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512);
772 * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024,
773 * overflow after 64.99 years.
774 * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
776 return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ);
780 u64 jiffies64_to_nsecs(u64 j)
782 #if !(NSEC_PER_SEC % HZ)
783 return (NSEC_PER_SEC / HZ) * j;
785 return div_u64(j * HZ_TO_NSEC_NUM, HZ_TO_NSEC_DEN);
788 EXPORT_SYMBOL(jiffies64_to_nsecs);
790 u64 jiffies64_to_msecs(const u64 j)
792 #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
793 return (MSEC_PER_SEC / HZ) * j;
795 return div_u64(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN);
798 EXPORT_SYMBOL(jiffies64_to_msecs);
801 * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64
805 * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
806 * And this doesn't return MAX_JIFFY_OFFSET since this function is designed
807 * for scheduler, not for use in device drivers to calculate timeout value.
810 * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
811 * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
813 u64 nsecs_to_jiffies64(u64 n)
815 #if (NSEC_PER_SEC % HZ) == 0
816 /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */
817 return div_u64(n, NSEC_PER_SEC / HZ);
818 #elif (HZ % 512) == 0
819 /* overflow after 292 years if HZ = 1024 */
820 return div_u64(n * HZ / 512, NSEC_PER_SEC / 512);
823 * Generic case - optimized for cases where HZ is a multiple of 3.
824 * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc.
826 return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ);
829 EXPORT_SYMBOL(nsecs_to_jiffies64);
832 * nsecs_to_jiffies - Convert nsecs in u64 to jiffies
836 * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
837 * And this doesn't return MAX_JIFFY_OFFSET since this function is designed
838 * for scheduler, not for use in device drivers to calculate timeout value.
841 * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
842 * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
844 unsigned long nsecs_to_jiffies(u64 n)
846 return (unsigned long)nsecs_to_jiffies64(n);
848 EXPORT_SYMBOL_GPL(nsecs_to_jiffies);
851 * Add two timespec64 values and do a safety check for overflow.
852 * It's assumed that both values are valid (>= 0).
853 * And, each timespec64 is in normalized form.
855 struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
856 const struct timespec64 rhs)
858 struct timespec64 res;
860 set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec,
861 lhs.tv_nsec + rhs.tv_nsec);
863 if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) {
864 res.tv_sec = TIME64_MAX;
871 int get_timespec64(struct timespec64 *ts,
872 const struct __kernel_timespec __user *uts)
874 struct __kernel_timespec kts;
877 ret = copy_from_user(&kts, uts, sizeof(kts));
881 ts->tv_sec = kts.tv_sec;
883 /* Zero out the padding for 32 bit systems or in compat mode */
884 if (IS_ENABLED(CONFIG_64BIT_TIME) && in_compat_syscall())
885 kts.tv_nsec &= 0xFFFFFFFFUL;
887 ts->tv_nsec = kts.tv_nsec;
891 EXPORT_SYMBOL_GPL(get_timespec64);
893 int put_timespec64(const struct timespec64 *ts,
894 struct __kernel_timespec __user *uts)
896 struct __kernel_timespec kts = {
897 .tv_sec = ts->tv_sec,
898 .tv_nsec = ts->tv_nsec
901 return copy_to_user(uts, &kts, sizeof(kts)) ? -EFAULT : 0;
903 EXPORT_SYMBOL_GPL(put_timespec64);
905 static int __get_old_timespec32(struct timespec64 *ts64,
906 const struct old_timespec32 __user *cts)
908 struct old_timespec32 ts;
911 ret = copy_from_user(&ts, cts, sizeof(ts));
915 ts64->tv_sec = ts.tv_sec;
916 ts64->tv_nsec = ts.tv_nsec;
921 static int __put_old_timespec32(const struct timespec64 *ts64,
922 struct old_timespec32 __user *cts)
924 struct old_timespec32 ts = {
925 .tv_sec = ts64->tv_sec,
926 .tv_nsec = ts64->tv_nsec
928 return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0;
931 int get_old_timespec32(struct timespec64 *ts, const void __user *uts)
933 if (COMPAT_USE_64BIT_TIME)
934 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
936 return __get_old_timespec32(ts, uts);
938 EXPORT_SYMBOL_GPL(get_old_timespec32);
940 int put_old_timespec32(const struct timespec64 *ts, void __user *uts)
942 if (COMPAT_USE_64BIT_TIME)
943 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
945 return __put_old_timespec32(ts, uts);
947 EXPORT_SYMBOL_GPL(put_old_timespec32);
949 int get_itimerspec64(struct itimerspec64 *it,
950 const struct __kernel_itimerspec __user *uit)
954 ret = get_timespec64(&it->it_interval, &uit->it_interval);
958 ret = get_timespec64(&it->it_value, &uit->it_value);
962 EXPORT_SYMBOL_GPL(get_itimerspec64);
964 int put_itimerspec64(const struct itimerspec64 *it,
965 struct __kernel_itimerspec __user *uit)
969 ret = put_timespec64(&it->it_interval, &uit->it_interval);
973 ret = put_timespec64(&it->it_value, &uit->it_value);
977 EXPORT_SYMBOL_GPL(put_itimerspec64);
979 int get_old_itimerspec32(struct itimerspec64 *its,
980 const struct old_itimerspec32 __user *uits)
983 if (__get_old_timespec32(&its->it_interval, &uits->it_interval) ||
984 __get_old_timespec32(&its->it_value, &uits->it_value))
988 EXPORT_SYMBOL_GPL(get_old_itimerspec32);
990 int put_old_itimerspec32(const struct itimerspec64 *its,
991 struct old_itimerspec32 __user *uits)
993 if (__put_old_timespec32(&its->it_interval, &uits->it_interval) ||
994 __put_old_timespec32(&its->it_value, &uits->it_value))
998 EXPORT_SYMBOL_GPL(put_old_itimerspec32);