1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright (C) 1991, 1992  Linus Torvalds
4  *
5  *  This file contains the interface functions for the various time related
6  *  system calls: time, stime, gettimeofday, settimeofday, adjtime
7  *
8  * Modification history:
9  *
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
25  */
26 
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>
35 #include <linux/fs.h>
36 #include <linux/math64.h>
37 #include <linux/ptrace.h>
38 
39 #include <linux/uaccess.h>
40 #include <linux/compat.h>
41 #include <asm/unistd.h>
42 
43 #include <generated/timeconst.h>
44 #include "timekeeping.h"
45 
46 /*
47  * The timezone where the local system is located.  Used as a default by some
48  * programs who obtain this value by using gettimeofday.
49  */
50 struct timezone sys_tz;
51 
52 EXPORT_SYMBOL(sys_tz);
53 
54 #ifdef __ARCH_WANT_SYS_TIME
55 
56 /*
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).
61  */
SYSCALL_DEFINE1(time,__kernel_old_time_t __user *,tloc)62 SYSCALL_DEFINE1(time, __kernel_old_time_t __user *, tloc)
63 {
64 	__kernel_old_time_t i = (__kernel_old_time_t)ktime_get_real_seconds();
65 
66 	if (tloc) {
67 		if (put_user(i,tloc))
68 			return -EFAULT;
69 	}
70 	force_successful_syscall_return();
71 	return i;
72 }
73 
74 /*
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).
79  */
80 
SYSCALL_DEFINE1(stime,__kernel_old_time_t __user *,tptr)81 SYSCALL_DEFINE1(stime, __kernel_old_time_t __user *, tptr)
82 {
83 	struct timespec64 tv;
84 	int err;
85 
86 	if (get_user(tv.tv_sec, tptr))
87 		return -EFAULT;
88 
89 	tv.tv_nsec = 0;
90 
91 	err = security_settime64(&tv, NULL);
92 	if (err)
93 		return err;
94 
95 	do_settimeofday64(&tv);
96 	return 0;
97 }
98 
99 #endif /* __ARCH_WANT_SYS_TIME */
100 
101 #ifdef CONFIG_COMPAT_32BIT_TIME
102 #ifdef __ARCH_WANT_SYS_TIME32
103 
104 /* old_time32_t is a 32 bit "long" and needs to get converted. */
SYSCALL_DEFINE1(time32,old_time32_t __user *,tloc)105 SYSCALL_DEFINE1(time32, old_time32_t __user *, tloc)
106 {
107 	old_time32_t i;
108 
109 	i = (old_time32_t)ktime_get_real_seconds();
110 
111 	if (tloc) {
112 		if (put_user(i,tloc))
113 			return -EFAULT;
114 	}
115 	force_successful_syscall_return();
116 	return i;
117 }
118 
SYSCALL_DEFINE1(stime32,old_time32_t __user *,tptr)119 SYSCALL_DEFINE1(stime32, old_time32_t __user *, tptr)
120 {
121 	struct timespec64 tv;
122 	int err;
123 
124 	if (get_user(tv.tv_sec, tptr))
125 		return -EFAULT;
126 
127 	tv.tv_nsec = 0;
128 
129 	err = security_settime64(&tv, NULL);
130 	if (err)
131 		return err;
132 
133 	do_settimeofday64(&tv);
134 	return 0;
135 }
136 
137 #endif /* __ARCH_WANT_SYS_TIME32 */
138 #endif
139 
SYSCALL_DEFINE2(gettimeofday,struct __kernel_old_timeval __user *,tv,struct timezone __user *,tz)140 SYSCALL_DEFINE2(gettimeofday, struct __kernel_old_timeval __user *, tv,
141 		struct timezone __user *, tz)
142 {
143 	if (likely(tv != NULL)) {
144 		struct timespec64 ts;
145 
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))
149 			return -EFAULT;
150 	}
151 	if (unlikely(tz != NULL)) {
152 		if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
153 			return -EFAULT;
154 	}
155 	return 0;
156 }
157 
158 /*
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.
167  */
168 
do_sys_settimeofday64(const struct timespec64 * tv,const struct timezone * tz)169 int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz)
170 {
171 	static int firsttime = 1;
172 	int error = 0;
173 
174 	if (tv && !timespec64_valid_settod(tv))
175 		return -EINVAL;
176 
177 	error = security_settime64(tv, tz);
178 	if (error)
179 		return error;
180 
181 	if (tz) {
182 		/* Verify we're within the +-15 hrs range */
183 		if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60)
184 			return -EINVAL;
185 
186 		sys_tz = *tz;
187 		update_vsyscall_tz();
188 		if (firsttime) {
189 			firsttime = 0;
190 			if (!tv)
191 				timekeeping_warp_clock();
192 		}
193 	}
194 	if (tv)
195 		return do_settimeofday64(tv);
196 	return 0;
197 }
198 
SYSCALL_DEFINE2(settimeofday,struct __kernel_old_timeval __user *,tv,struct timezone __user *,tz)199 SYSCALL_DEFINE2(settimeofday, struct __kernel_old_timeval __user *, tv,
200 		struct timezone __user *, tz)
201 {
202 	struct timespec64 new_ts;
203 	struct timezone new_tz;
204 
205 	if (tv) {
206 		if (get_user(new_ts.tv_sec, &tv->tv_sec) ||
207 		    get_user(new_ts.tv_nsec, &tv->tv_usec))
208 			return -EFAULT;
209 
210 		if (new_ts.tv_nsec > USEC_PER_SEC || new_ts.tv_nsec < 0)
211 			return -EINVAL;
212 
213 		new_ts.tv_nsec *= NSEC_PER_USEC;
214 	}
215 	if (tz) {
216 		if (copy_from_user(&new_tz, tz, sizeof(*tz)))
217 			return -EFAULT;
218 	}
219 
220 	return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL);
221 }
222 
223 #ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE2(gettimeofday,struct old_timeval32 __user *,tv,struct timezone __user *,tz)224 COMPAT_SYSCALL_DEFINE2(gettimeofday, struct old_timeval32 __user *, tv,
225 		       struct timezone __user *, tz)
226 {
227 	if (tv) {
228 		struct timespec64 ts;
229 
230 		ktime_get_real_ts64(&ts);
231 		if (put_user(ts.tv_sec, &tv->tv_sec) ||
232 		    put_user(ts.tv_nsec / 1000, &tv->tv_usec))
233 			return -EFAULT;
234 	}
235 	if (tz) {
236 		if (copy_to_user(tz, &sys_tz, sizeof(sys_tz)))
237 			return -EFAULT;
238 	}
239 
240 	return 0;
241 }
242 
COMPAT_SYSCALL_DEFINE2(settimeofday,struct old_timeval32 __user *,tv,struct timezone __user *,tz)243 COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv,
244 		       struct timezone __user *, tz)
245 {
246 	struct timespec64 new_ts;
247 	struct timezone new_tz;
248 
249 	if (tv) {
250 		if (get_user(new_ts.tv_sec, &tv->tv_sec) ||
251 		    get_user(new_ts.tv_nsec, &tv->tv_usec))
252 			return -EFAULT;
253 
254 		if (new_ts.tv_nsec > USEC_PER_SEC || new_ts.tv_nsec < 0)
255 			return -EINVAL;
256 
257 		new_ts.tv_nsec *= NSEC_PER_USEC;
258 	}
259 	if (tz) {
260 		if (copy_from_user(&new_tz, tz, sizeof(*tz)))
261 			return -EFAULT;
262 	}
263 
264 	return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL);
265 }
266 #endif
267 
268 #ifdef CONFIG_64BIT
SYSCALL_DEFINE1(adjtimex,struct __kernel_timex __user *,txc_p)269 SYSCALL_DEFINE1(adjtimex, struct __kernel_timex __user *, txc_p)
270 {
271 	struct __kernel_timex txc;		/* Local copy of parameter */
272 	int ret;
273 
274 	/* Copy the user data space into the kernel copy
275 	 * structure. But bear in mind that the structures
276 	 * may change
277 	 */
278 	if (copy_from_user(&txc, txc_p, sizeof(struct __kernel_timex)))
279 		return -EFAULT;
280 	ret = do_adjtimex(&txc);
281 	return copy_to_user(txc_p, &txc, sizeof(struct __kernel_timex)) ? -EFAULT : ret;
282 }
283 #endif
284 
285 #ifdef CONFIG_COMPAT_32BIT_TIME
get_old_timex32(struct __kernel_timex * txc,const struct old_timex32 __user * utp)286 int get_old_timex32(struct __kernel_timex *txc, const struct old_timex32 __user *utp)
287 {
288 	struct old_timex32 tx32;
289 
290 	memset(txc, 0, sizeof(struct __kernel_timex));
291 	if (copy_from_user(&tx32, utp, sizeof(struct old_timex32)))
292 		return -EFAULT;
293 
294 	txc->modes = tx32.modes;
295 	txc->offset = tx32.offset;
296 	txc->freq = tx32.freq;
297 	txc->maxerror = tx32.maxerror;
298 	txc->esterror = tx32.esterror;
299 	txc->status = tx32.status;
300 	txc->constant = tx32.constant;
301 	txc->precision = tx32.precision;
302 	txc->tolerance = tx32.tolerance;
303 	txc->time.tv_sec = tx32.time.tv_sec;
304 	txc->time.tv_usec = tx32.time.tv_usec;
305 	txc->tick = tx32.tick;
306 	txc->ppsfreq = tx32.ppsfreq;
307 	txc->jitter = tx32.jitter;
308 	txc->shift = tx32.shift;
309 	txc->stabil = tx32.stabil;
310 	txc->jitcnt = tx32.jitcnt;
311 	txc->calcnt = tx32.calcnt;
312 	txc->errcnt = tx32.errcnt;
313 	txc->stbcnt = tx32.stbcnt;
314 
315 	return 0;
316 }
317 
put_old_timex32(struct old_timex32 __user * utp,const struct __kernel_timex * txc)318 int put_old_timex32(struct old_timex32 __user *utp, const struct __kernel_timex *txc)
319 {
320 	struct old_timex32 tx32;
321 
322 	memset(&tx32, 0, sizeof(struct old_timex32));
323 	tx32.modes = txc->modes;
324 	tx32.offset = txc->offset;
325 	tx32.freq = txc->freq;
326 	tx32.maxerror = txc->maxerror;
327 	tx32.esterror = txc->esterror;
328 	tx32.status = txc->status;
329 	tx32.constant = txc->constant;
330 	tx32.precision = txc->precision;
331 	tx32.tolerance = txc->tolerance;
332 	tx32.time.tv_sec = txc->time.tv_sec;
333 	tx32.time.tv_usec = txc->time.tv_usec;
334 	tx32.tick = txc->tick;
335 	tx32.ppsfreq = txc->ppsfreq;
336 	tx32.jitter = txc->jitter;
337 	tx32.shift = txc->shift;
338 	tx32.stabil = txc->stabil;
339 	tx32.jitcnt = txc->jitcnt;
340 	tx32.calcnt = txc->calcnt;
341 	tx32.errcnt = txc->errcnt;
342 	tx32.stbcnt = txc->stbcnt;
343 	tx32.tai = txc->tai;
344 	if (copy_to_user(utp, &tx32, sizeof(struct old_timex32)))
345 		return -EFAULT;
346 	return 0;
347 }
348 
SYSCALL_DEFINE1(adjtimex_time32,struct old_timex32 __user *,utp)349 SYSCALL_DEFINE1(adjtimex_time32, struct old_timex32 __user *, utp)
350 {
351 	struct __kernel_timex txc;
352 	int err, ret;
353 
354 	err = get_old_timex32(&txc, utp);
355 	if (err)
356 		return err;
357 
358 	ret = do_adjtimex(&txc);
359 
360 	err = put_old_timex32(utp, &txc);
361 	if (err)
362 		return err;
363 
364 	return ret;
365 }
366 #endif
367 
368 /*
369  * Convert jiffies to milliseconds and back.
370  *
371  * Avoid unnecessary multiplications/divisions in the
372  * two most common HZ cases:
373  */
jiffies_to_msecs(const unsigned long j)374 unsigned int jiffies_to_msecs(const unsigned long j)
375 {
376 #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
377 	return (MSEC_PER_SEC / HZ) * j;
378 #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC)
379 	return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC);
380 #else
381 # if BITS_PER_LONG == 32
382 	return (HZ_TO_MSEC_MUL32 * j + (1ULL << HZ_TO_MSEC_SHR32) - 1) >>
383 	       HZ_TO_MSEC_SHR32;
384 # else
385 	return DIV_ROUND_UP(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN);
386 # endif
387 #endif
388 }
389 EXPORT_SYMBOL(jiffies_to_msecs);
390 
jiffies_to_usecs(const unsigned long j)391 unsigned int jiffies_to_usecs(const unsigned long j)
392 {
393 	/*
394 	 * Hz usually doesn't go much further MSEC_PER_SEC.
395 	 * jiffies_to_usecs() and usecs_to_jiffies() depend on that.
396 	 */
397 	BUILD_BUG_ON(HZ > USEC_PER_SEC);
398 
399 #if !(USEC_PER_SEC % HZ)
400 	return (USEC_PER_SEC / HZ) * j;
401 #else
402 # if BITS_PER_LONG == 32
403 	return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32;
404 # else
405 	return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN;
406 # endif
407 #endif
408 }
409 EXPORT_SYMBOL(jiffies_to_usecs);
410 
411 /*
412  * mktime64 - Converts date to seconds.
413  * Converts Gregorian date to seconds since 1970-01-01 00:00:00.
414  * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
415  * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
416  *
417  * [For the Julian calendar (which was used in Russia before 1917,
418  * Britain & colonies before 1752, anywhere else before 1582,
419  * and is still in use by some communities) leave out the
420  * -year/100+year/400 terms, and add 10.]
421  *
422  * This algorithm was first published by Gauss (I think).
423  *
424  * A leap second can be indicated by calling this function with sec as
425  * 60 (allowable under ISO 8601).  The leap second is treated the same
426  * as the following second since they don't exist in UNIX time.
427  *
428  * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight
429  * tomorrow - (allowable under ISO 8601) is supported.
430  */
mktime64(const unsigned int year0,const unsigned int mon0,const unsigned int day,const unsigned int hour,const unsigned int min,const unsigned int sec)431 time64_t mktime64(const unsigned int year0, const unsigned int mon0,
432 		const unsigned int day, const unsigned int hour,
433 		const unsigned int min, const unsigned int sec)
434 {
435 	unsigned int mon = mon0, year = year0;
436 
437 	/* 1..12 -> 11,12,1..10 */
438 	if (0 >= (int) (mon -= 2)) {
439 		mon += 12;	/* Puts Feb last since it has leap day */
440 		year -= 1;
441 	}
442 
443 	return ((((time64_t)
444 		  (year/4 - year/100 + year/400 + 367*mon/12 + day) +
445 		  year*365 - 719499
446 	    )*24 + hour /* now have hours - midnight tomorrow handled here */
447 	  )*60 + min /* now have minutes */
448 	)*60 + sec; /* finally seconds */
449 }
450 EXPORT_SYMBOL(mktime64);
451 
ns_to_kernel_old_timeval(const s64 nsec)452 struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec)
453 {
454 	struct timespec64 ts = ns_to_timespec64(nsec);
455 	struct __kernel_old_timeval tv;
456 
457 	tv.tv_sec = ts.tv_sec;
458 	tv.tv_usec = (suseconds_t)ts.tv_nsec / 1000;
459 
460 	return tv;
461 }
462 EXPORT_SYMBOL(ns_to_kernel_old_timeval);
463 
464 /**
465  * set_normalized_timespec - set timespec sec and nsec parts and normalize
466  *
467  * @ts:		pointer to timespec variable to be set
468  * @sec:	seconds to set
469  * @nsec:	nanoseconds to set
470  *
471  * Set seconds and nanoseconds field of a timespec variable and
472  * normalize to the timespec storage format
473  *
474  * Note: The tv_nsec part is always in the range of
475  *	0 <= tv_nsec < NSEC_PER_SEC
476  * For negative values only the tv_sec field is negative !
477  */
set_normalized_timespec64(struct timespec64 * ts,time64_t sec,s64 nsec)478 void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec)
479 {
480 	while (nsec >= NSEC_PER_SEC) {
481 		/*
482 		 * The following asm() prevents the compiler from
483 		 * optimising this loop into a modulo operation. See
484 		 * also __iter_div_u64_rem() in include/linux/time.h
485 		 */
486 		asm("" : "+rm"(nsec));
487 		nsec -= NSEC_PER_SEC;
488 		++sec;
489 	}
490 	while (nsec < 0) {
491 		asm("" : "+rm"(nsec));
492 		nsec += NSEC_PER_SEC;
493 		--sec;
494 	}
495 	ts->tv_sec = sec;
496 	ts->tv_nsec = nsec;
497 }
498 EXPORT_SYMBOL(set_normalized_timespec64);
499 
500 /**
501  * ns_to_timespec64 - Convert nanoseconds to timespec64
502  * @nsec:       the nanoseconds value to be converted
503  *
504  * Returns the timespec64 representation of the nsec parameter.
505  */
ns_to_timespec64(const s64 nsec)506 struct timespec64 ns_to_timespec64(const s64 nsec)
507 {
508 	struct timespec64 ts = { 0, 0 };
509 	s32 rem;
510 
511 	if (likely(nsec > 0)) {
512 		ts.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
513 		ts.tv_nsec = rem;
514 	} else if (nsec < 0) {
515 		/*
516 		 * With negative times, tv_sec points to the earlier
517 		 * second, and tv_nsec counts the nanoseconds since
518 		 * then, so tv_nsec is always a positive number.
519 		 */
520 		ts.tv_sec = -div_u64_rem(-nsec - 1, NSEC_PER_SEC, &rem) - 1;
521 		ts.tv_nsec = NSEC_PER_SEC - rem - 1;
522 	}
523 
524 	return ts;
525 }
526 EXPORT_SYMBOL(ns_to_timespec64);
527 
528 /**
529  * msecs_to_jiffies: - convert milliseconds to jiffies
530  * @m:	time in milliseconds
531  *
532  * conversion is done as follows:
533  *
534  * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)
535  *
536  * - 'too large' values [that would result in larger than
537  *   MAX_JIFFY_OFFSET values] mean 'infinite timeout' too.
538  *
539  * - all other values are converted to jiffies by either multiplying
540  *   the input value by a factor or dividing it with a factor and
541  *   handling any 32-bit overflows.
542  *   for the details see __msecs_to_jiffies()
543  *
544  * msecs_to_jiffies() checks for the passed in value being a constant
545  * via __builtin_constant_p() allowing gcc to eliminate most of the
546  * code, __msecs_to_jiffies() is called if the value passed does not
547  * allow constant folding and the actual conversion must be done at
548  * runtime.
549  * the _msecs_to_jiffies helpers are the HZ dependent conversion
550  * routines found in include/linux/jiffies.h
551  */
__msecs_to_jiffies(const unsigned int m)552 unsigned long __msecs_to_jiffies(const unsigned int m)
553 {
554 	/*
555 	 * Negative value, means infinite timeout:
556 	 */
557 	if ((int)m < 0)
558 		return MAX_JIFFY_OFFSET;
559 	return _msecs_to_jiffies(m);
560 }
561 EXPORT_SYMBOL(__msecs_to_jiffies);
562 
__usecs_to_jiffies(const unsigned int u)563 unsigned long __usecs_to_jiffies(const unsigned int u)
564 {
565 	if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
566 		return MAX_JIFFY_OFFSET;
567 	return _usecs_to_jiffies(u);
568 }
569 EXPORT_SYMBOL(__usecs_to_jiffies);
570 
571 /*
572  * The TICK_NSEC - 1 rounds up the value to the next resolution.  Note
573  * that a remainder subtract here would not do the right thing as the
574  * resolution values don't fall on second boundaries.  I.e. the line:
575  * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding.
576  * Note that due to the small error in the multiplier here, this
577  * rounding is incorrect for sufficiently large values of tv_nsec, but
578  * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're
579  * OK.
580  *
581  * Rather, we just shift the bits off the right.
582  *
583  * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec
584  * value to a scaled second value.
585  */
586 
587 unsigned long
timespec64_to_jiffies(const struct timespec64 * value)588 timespec64_to_jiffies(const struct timespec64 *value)
589 {
590 	u64 sec = value->tv_sec;
591 	long nsec = value->tv_nsec + TICK_NSEC - 1;
592 
593 	if (sec >= MAX_SEC_IN_JIFFIES){
594 		sec = MAX_SEC_IN_JIFFIES;
595 		nsec = 0;
596 	}
597 	return ((sec * SEC_CONVERSION) +
598 		(((u64)nsec * NSEC_CONVERSION) >>
599 		 (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
600 
601 }
602 EXPORT_SYMBOL(timespec64_to_jiffies);
603 
604 void
jiffies_to_timespec64(const unsigned long jiffies,struct timespec64 * value)605 jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value)
606 {
607 	/*
608 	 * Convert jiffies to nanoseconds and separate with
609 	 * one divide.
610 	 */
611 	u32 rem;
612 	value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
613 				    NSEC_PER_SEC, &rem);
614 	value->tv_nsec = rem;
615 }
616 EXPORT_SYMBOL(jiffies_to_timespec64);
617 
618 /*
619  * Convert jiffies/jiffies_64 to clock_t and back.
620  */
jiffies_to_clock_t(unsigned long x)621 clock_t jiffies_to_clock_t(unsigned long x)
622 {
623 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
624 # if HZ < USER_HZ
625 	return x * (USER_HZ / HZ);
626 # else
627 	return x / (HZ / USER_HZ);
628 # endif
629 #else
630 	return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ);
631 #endif
632 }
633 EXPORT_SYMBOL(jiffies_to_clock_t);
634 
clock_t_to_jiffies(unsigned long x)635 unsigned long clock_t_to_jiffies(unsigned long x)
636 {
637 #if (HZ % USER_HZ)==0
638 	if (x >= ~0UL / (HZ / USER_HZ))
639 		return ~0UL;
640 	return x * (HZ / USER_HZ);
641 #else
642 	/* Don't worry about loss of precision here .. */
643 	if (x >= ~0UL / HZ * USER_HZ)
644 		return ~0UL;
645 
646 	/* .. but do try to contain it here */
647 	return div_u64((u64)x * HZ, USER_HZ);
648 #endif
649 }
650 EXPORT_SYMBOL(clock_t_to_jiffies);
651 
jiffies_64_to_clock_t(u64 x)652 u64 jiffies_64_to_clock_t(u64 x)
653 {
654 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0
655 # if HZ < USER_HZ
656 	x = div_u64(x * USER_HZ, HZ);
657 # elif HZ > USER_HZ
658 	x = div_u64(x, HZ / USER_HZ);
659 # else
660 	/* Nothing to do */
661 # endif
662 #else
663 	/*
664 	 * There are better ways that don't overflow early,
665 	 * but even this doesn't overflow in hundreds of years
666 	 * in 64 bits, so..
667 	 */
668 	x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ));
669 #endif
670 	return x;
671 }
672 EXPORT_SYMBOL(jiffies_64_to_clock_t);
673 
nsec_to_clock_t(u64 x)674 u64 nsec_to_clock_t(u64 x)
675 {
676 #if (NSEC_PER_SEC % USER_HZ) == 0
677 	return div_u64(x, NSEC_PER_SEC / USER_HZ);
678 #elif (USER_HZ % 512) == 0
679 	return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512);
680 #else
681 	/*
682          * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024,
683          * overflow after 64.99 years.
684          * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
685          */
686 	return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ);
687 #endif
688 }
689 
jiffies64_to_nsecs(u64 j)690 u64 jiffies64_to_nsecs(u64 j)
691 {
692 #if !(NSEC_PER_SEC % HZ)
693 	return (NSEC_PER_SEC / HZ) * j;
694 # else
695 	return div_u64(j * HZ_TO_NSEC_NUM, HZ_TO_NSEC_DEN);
696 #endif
697 }
698 EXPORT_SYMBOL(jiffies64_to_nsecs);
699 
jiffies64_to_msecs(const u64 j)700 u64 jiffies64_to_msecs(const u64 j)
701 {
702 #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
703 	return (MSEC_PER_SEC / HZ) * j;
704 #else
705 	return div_u64(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN);
706 #endif
707 }
708 EXPORT_SYMBOL(jiffies64_to_msecs);
709 
710 /**
711  * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64
712  *
713  * @n:	nsecs in u64
714  *
715  * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
716  * And this doesn't return MAX_JIFFY_OFFSET since this function is designed
717  * for scheduler, not for use in device drivers to calculate timeout value.
718  *
719  * note:
720  *   NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
721  *   ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
722  */
nsecs_to_jiffies64(u64 n)723 u64 nsecs_to_jiffies64(u64 n)
724 {
725 #if (NSEC_PER_SEC % HZ) == 0
726 	/* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */
727 	return div_u64(n, NSEC_PER_SEC / HZ);
728 #elif (HZ % 512) == 0
729 	/* overflow after 292 years if HZ = 1024 */
730 	return div_u64(n * HZ / 512, NSEC_PER_SEC / 512);
731 #else
732 	/*
733 	 * Generic case - optimized for cases where HZ is a multiple of 3.
734 	 * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc.
735 	 */
736 	return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ);
737 #endif
738 }
739 EXPORT_SYMBOL(nsecs_to_jiffies64);
740 
741 /**
742  * nsecs_to_jiffies - Convert nsecs in u64 to jiffies
743  *
744  * @n:	nsecs in u64
745  *
746  * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
747  * And this doesn't return MAX_JIFFY_OFFSET since this function is designed
748  * for scheduler, not for use in device drivers to calculate timeout value.
749  *
750  * note:
751  *   NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
752  *   ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
753  */
nsecs_to_jiffies(u64 n)754 unsigned long nsecs_to_jiffies(u64 n)
755 {
756 	return (unsigned long)nsecs_to_jiffies64(n);
757 }
758 EXPORT_SYMBOL_GPL(nsecs_to_jiffies);
759 
760 /*
761  * Add two timespec64 values and do a safety check for overflow.
762  * It's assumed that both values are valid (>= 0).
763  * And, each timespec64 is in normalized form.
764  */
timespec64_add_safe(const struct timespec64 lhs,const struct timespec64 rhs)765 struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
766 				const struct timespec64 rhs)
767 {
768 	struct timespec64 res;
769 
770 	set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec,
771 			lhs.tv_nsec + rhs.tv_nsec);
772 
773 	if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) {
774 		res.tv_sec = TIME64_MAX;
775 		res.tv_nsec = 0;
776 	}
777 
778 	return res;
779 }
780 
get_timespec64(struct timespec64 * ts,const struct __kernel_timespec __user * uts)781 int get_timespec64(struct timespec64 *ts,
782 		   const struct __kernel_timespec __user *uts)
783 {
784 	struct __kernel_timespec kts;
785 	int ret;
786 
787 	ret = copy_from_user(&kts, uts, sizeof(kts));
788 	if (ret)
789 		return -EFAULT;
790 
791 	ts->tv_sec = kts.tv_sec;
792 
793 	/* Zero out the padding in compat mode */
794 	if (in_compat_syscall())
795 		kts.tv_nsec &= 0xFFFFFFFFUL;
796 
797 	/* In 32-bit mode, this drops the padding */
798 	ts->tv_nsec = kts.tv_nsec;
799 
800 	return 0;
801 }
802 EXPORT_SYMBOL_GPL(get_timespec64);
803 
put_timespec64(const struct timespec64 * ts,struct __kernel_timespec __user * uts)804 int put_timespec64(const struct timespec64 *ts,
805 		   struct __kernel_timespec __user *uts)
806 {
807 	struct __kernel_timespec kts = {
808 		.tv_sec = ts->tv_sec,
809 		.tv_nsec = ts->tv_nsec
810 	};
811 
812 	return copy_to_user(uts, &kts, sizeof(kts)) ? -EFAULT : 0;
813 }
814 EXPORT_SYMBOL_GPL(put_timespec64);
815 
__get_old_timespec32(struct timespec64 * ts64,const struct old_timespec32 __user * cts)816 static int __get_old_timespec32(struct timespec64 *ts64,
817 				   const struct old_timespec32 __user *cts)
818 {
819 	struct old_timespec32 ts;
820 	int ret;
821 
822 	ret = copy_from_user(&ts, cts, sizeof(ts));
823 	if (ret)
824 		return -EFAULT;
825 
826 	ts64->tv_sec = ts.tv_sec;
827 	ts64->tv_nsec = ts.tv_nsec;
828 
829 	return 0;
830 }
831 
__put_old_timespec32(const struct timespec64 * ts64,struct old_timespec32 __user * cts)832 static int __put_old_timespec32(const struct timespec64 *ts64,
833 				   struct old_timespec32 __user *cts)
834 {
835 	struct old_timespec32 ts = {
836 		.tv_sec = ts64->tv_sec,
837 		.tv_nsec = ts64->tv_nsec
838 	};
839 	return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0;
840 }
841 
get_old_timespec32(struct timespec64 * ts,const void __user * uts)842 int get_old_timespec32(struct timespec64 *ts, const void __user *uts)
843 {
844 	if (COMPAT_USE_64BIT_TIME)
845 		return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
846 	else
847 		return __get_old_timespec32(ts, uts);
848 }
849 EXPORT_SYMBOL_GPL(get_old_timespec32);
850 
put_old_timespec32(const struct timespec64 * ts,void __user * uts)851 int put_old_timespec32(const struct timespec64 *ts, void __user *uts)
852 {
853 	if (COMPAT_USE_64BIT_TIME)
854 		return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
855 	else
856 		return __put_old_timespec32(ts, uts);
857 }
858 EXPORT_SYMBOL_GPL(put_old_timespec32);
859 
get_itimerspec64(struct itimerspec64 * it,const struct __kernel_itimerspec __user * uit)860 int get_itimerspec64(struct itimerspec64 *it,
861 			const struct __kernel_itimerspec __user *uit)
862 {
863 	int ret;
864 
865 	ret = get_timespec64(&it->it_interval, &uit->it_interval);
866 	if (ret)
867 		return ret;
868 
869 	ret = get_timespec64(&it->it_value, &uit->it_value);
870 
871 	return ret;
872 }
873 EXPORT_SYMBOL_GPL(get_itimerspec64);
874 
put_itimerspec64(const struct itimerspec64 * it,struct __kernel_itimerspec __user * uit)875 int put_itimerspec64(const struct itimerspec64 *it,
876 			struct __kernel_itimerspec __user *uit)
877 {
878 	int ret;
879 
880 	ret = put_timespec64(&it->it_interval, &uit->it_interval);
881 	if (ret)
882 		return ret;
883 
884 	ret = put_timespec64(&it->it_value, &uit->it_value);
885 
886 	return ret;
887 }
888 EXPORT_SYMBOL_GPL(put_itimerspec64);
889 
get_old_itimerspec32(struct itimerspec64 * its,const struct old_itimerspec32 __user * uits)890 int get_old_itimerspec32(struct itimerspec64 *its,
891 			const struct old_itimerspec32 __user *uits)
892 {
893 
894 	if (__get_old_timespec32(&its->it_interval, &uits->it_interval) ||
895 	    __get_old_timespec32(&its->it_value, &uits->it_value))
896 		return -EFAULT;
897 	return 0;
898 }
899 EXPORT_SYMBOL_GPL(get_old_itimerspec32);
900 
put_old_itimerspec32(const struct itimerspec64 * its,struct old_itimerspec32 __user * uits)901 int put_old_itimerspec32(const struct itimerspec64 *its,
902 			struct old_itimerspec32 __user *uits)
903 {
904 	if (__put_old_timespec32(&its->it_interval, &uits->it_interval) ||
905 	    __put_old_timespec32(&its->it_value, &uits->it_value))
906 		return -EFAULT;
907 	return 0;
908 }
909 EXPORT_SYMBOL_GPL(put_old_itimerspec32);
910