Line data Source code
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 : */
62 0 : SYSCALL_DEFINE1(time, __kernel_old_time_t __user *, tloc)
63 : {
64 0 : __kernel_old_time_t i = (__kernel_old_time_t)ktime_get_real_seconds();
65 :
66 0 : if (tloc) {
67 0 : 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 :
81 0 : SYSCALL_DEFINE1(stime, __kernel_old_time_t __user *, tptr)
82 : {
83 : struct timespec64 tv;
84 : int err;
85 :
86 0 : if (get_user(tv.tv_sec, tptr))
87 : return -EFAULT;
88 :
89 0 : tv.tv_nsec = 0;
90 :
91 0 : err = security_settime64(&tv, NULL);
92 0 : if (err)
93 0 : return err;
94 :
95 0 : do_settimeofday64(&tv);
96 0 : 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. */
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 :
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 :
140 0 : SYSCALL_DEFINE2(gettimeofday, struct __kernel_old_timeval __user *, tv,
141 : struct timezone __user *, tz)
142 : {
143 0 : if (likely(tv != NULL)) {
144 : struct timespec64 ts;
145 :
146 0 : ktime_get_real_ts64(&ts);
147 0 : if (put_user(ts.tv_sec, &tv->tv_sec) ||
148 0 : put_user(ts.tv_nsec / 1000, &tv->tv_usec))
149 0 : return -EFAULT;
150 : }
151 0 : if (unlikely(tz != NULL)) {
152 0 : 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 :
169 0 : int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz)
170 : {
171 : static int firsttime = 1;
172 0 : int error = 0;
173 :
174 0 : if (tv && !timespec64_valid_settod(tv))
175 : return -EINVAL;
176 :
177 0 : error = security_settime64(tv, tz);
178 0 : if (error)
179 : return error;
180 :
181 0 : if (tz) {
182 : /* Verify we're within the +-15 hrs range */
183 0 : if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60)
184 : return -EINVAL;
185 :
186 0 : sys_tz = *tz;
187 : update_vsyscall_tz();
188 0 : if (firsttime) {
189 0 : firsttime = 0;
190 0 : if (!tv)
191 0 : timekeeping_warp_clock();
192 : }
193 : }
194 0 : if (tv)
195 0 : return do_settimeofday64(tv);
196 : return 0;
197 : }
198 :
199 0 : 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 0 : if (tv) {
206 0 : if (get_user(new_ts.tv_sec, &tv->tv_sec) ||
207 0 : get_user(new_ts.tv_nsec, &tv->tv_usec))
208 : return -EFAULT;
209 :
210 0 : if (new_ts.tv_nsec > USEC_PER_SEC || new_ts.tv_nsec < 0)
211 : return -EINVAL;
212 :
213 0 : new_ts.tv_nsec *= NSEC_PER_USEC;
214 : }
215 0 : if (tz) {
216 0 : if (copy_from_user(&new_tz, tz, sizeof(*tz)))
217 : return -EFAULT;
218 : }
219 :
220 0 : return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL);
221 : }
222 :
223 : #ifdef CONFIG_COMPAT
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 :
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
269 0 : 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 0 : if (copy_from_user(&txc, txc_p, sizeof(struct __kernel_timex)))
279 : return -EFAULT;
280 0 : ret = do_adjtimex(&txc);
281 0 : return copy_to_user(txc_p, &txc, sizeof(struct __kernel_timex)) ? -EFAULT : ret;
282 : }
283 : #endif
284 :
285 : #ifdef CONFIG_COMPAT_32BIT_TIME
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 :
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 :
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 : */
374 0 : unsigned int jiffies_to_msecs(const unsigned long j)
375 : {
376 : #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
377 0 : 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 :
391 0 : 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 0 : 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 : */
431 0 : 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 0 : unsigned int mon = mon0, year = year0;
436 :
437 : /* 1..12 -> 11,12,1..10 */
438 0 : if (0 >= (int) (mon -= 2)) {
439 0 : mon += 12; /* Puts Feb last since it has leap day */
440 0 : year -= 1;
441 : }
442 :
443 0 : return ((((time64_t)
444 0 : (year/4 - year/100 + year/400 + 367*mon/12 + day) +
445 0 : year*365 - 719499
446 0 : )*24 + hour /* now have hours - midnight tomorrow handled here */
447 0 : )*60 + min /* now have minutes */
448 0 : )*60 + sec; /* finally seconds */
449 : }
450 : EXPORT_SYMBOL(mktime64);
451 :
452 0 : struct __kernel_old_timeval ns_to_kernel_old_timeval(s64 nsec)
453 : {
454 0 : struct timespec64 ts = ns_to_timespec64(nsec);
455 : struct __kernel_old_timeval tv;
456 :
457 0 : tv.tv_sec = ts.tv_sec;
458 0 : tv.tv_usec = (suseconds_t)ts.tv_nsec / 1000;
459 :
460 0 : return tv;
461 : }
462 : EXPORT_SYMBOL(ns_to_kernel_old_timeval);
463 :
464 : /**
465 : * set_normalized_timespec64 - 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 : */
478 4 : void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec)
479 : {
480 8 : 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 0 : asm("" : "+rm"(nsec));
487 0 : nsec -= NSEC_PER_SEC;
488 0 : ++sec;
489 : }
490 6 : while (nsec < 0) {
491 2 : asm("" : "+rm"(nsec));
492 2 : nsec += NSEC_PER_SEC;
493 2 : --sec;
494 : }
495 4 : ts->tv_sec = sec;
496 4 : ts->tv_nsec = nsec;
497 4 : }
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 : */
506 1 : struct timespec64 ns_to_timespec64(s64 nsec)
507 : {
508 1 : struct timespec64 ts = { 0, 0 };
509 : s32 rem;
510 :
511 1 : if (likely(nsec > 0)) {
512 0 : ts.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem);
513 0 : ts.tv_nsec = rem;
514 1 : } 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 0 : ts.tv_sec = -div_u64_rem(-nsec - 1, NSEC_PER_SEC, &rem) - 1;
521 0 : ts.tv_nsec = NSEC_PER_SEC - rem - 1;
522 : }
523 :
524 1 : 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 : */
552 0 : unsigned long __msecs_to_jiffies(const unsigned int m)
553 : {
554 : /*
555 : * Negative value, means infinite timeout:
556 : */
557 0 : if ((int)m < 0)
558 : return MAX_JIFFY_OFFSET;
559 0 : return _msecs_to_jiffies(m);
560 : }
561 : EXPORT_SYMBOL(__msecs_to_jiffies);
562 :
563 0 : unsigned long __usecs_to_jiffies(const unsigned int u)
564 : {
565 0 : if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
566 : return MAX_JIFFY_OFFSET;
567 0 : 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
588 0 : timespec64_to_jiffies(const struct timespec64 *value)
589 : {
590 0 : u64 sec = value->tv_sec;
591 0 : long nsec = value->tv_nsec + TICK_NSEC - 1;
592 :
593 0 : if (sec >= MAX_SEC_IN_JIFFIES){
594 0 : sec = MAX_SEC_IN_JIFFIES;
595 0 : nsec = 0;
596 : }
597 0 : return ((sec * SEC_CONVERSION) +
598 0 : (((u64)nsec * NSEC_CONVERSION) >>
599 0 : (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
600 :
601 : }
602 : EXPORT_SYMBOL(timespec64_to_jiffies);
603 :
604 : void
605 0 : 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 0 : value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC,
613 : NSEC_PER_SEC, &rem);
614 0 : value->tv_nsec = rem;
615 0 : }
616 : EXPORT_SYMBOL(jiffies_to_timespec64);
617 :
618 : /*
619 : * Convert jiffies/jiffies_64 to clock_t and back.
620 : */
621 0 : 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 0 : 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 :
635 0 : unsigned long clock_t_to_jiffies(unsigned long x)
636 : {
637 : #if (HZ % USER_HZ)==0
638 0 : if (x >= ~0UL / (HZ / USER_HZ))
639 : return ~0UL;
640 0 : 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 :
652 0 : 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 0 : return x;
671 : }
672 : EXPORT_SYMBOL(jiffies_64_to_clock_t);
673 :
674 320 : u64 nsec_to_clock_t(u64 x)
675 : {
676 : #if (NSEC_PER_SEC % USER_HZ) == 0
677 320 : 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 :
690 0 : u64 jiffies64_to_nsecs(u64 j)
691 : {
692 : #if !(NSEC_PER_SEC % HZ)
693 0 : 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 :
700 0 : u64 jiffies64_to_msecs(const u64 j)
701 : {
702 : #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
703 0 : 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 : */
723 0 : 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 0 : 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 : */
754 0 : unsigned long nsecs_to_jiffies(u64 n)
755 : {
756 0 : 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 : */
765 0 : struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
766 : const struct timespec64 rhs)
767 : {
768 : struct timespec64 res;
769 :
770 0 : set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec,
771 0 : lhs.tv_nsec + rhs.tv_nsec);
772 :
773 0 : if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) {
774 0 : res.tv_sec = TIME64_MAX;
775 0 : res.tv_nsec = 0;
776 : }
777 :
778 0 : return res;
779 : }
780 :
781 0 : int get_timespec64(struct timespec64 *ts,
782 : const struct __kernel_timespec __user *uts)
783 : {
784 : struct __kernel_timespec kts;
785 : int ret;
786 :
787 0 : ret = copy_from_user(&kts, uts, sizeof(kts));
788 0 : if (ret)
789 : return -EFAULT;
790 :
791 0 : 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 0 : ts->tv_nsec = kts.tv_nsec;
799 :
800 0 : return 0;
801 : }
802 : EXPORT_SYMBOL_GPL(get_timespec64);
803 :
804 0 : int put_timespec64(const struct timespec64 *ts,
805 : struct __kernel_timespec __user *uts)
806 : {
807 0 : struct __kernel_timespec kts = {
808 0 : .tv_sec = ts->tv_sec,
809 0 : .tv_nsec = ts->tv_nsec
810 : };
811 :
812 0 : return copy_to_user(uts, &kts, sizeof(kts)) ? -EFAULT : 0;
813 : }
814 : EXPORT_SYMBOL_GPL(put_timespec64);
815 :
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 0 : ret = copy_from_user(&ts, cts, sizeof(ts));
823 0 : if (ret)
824 : return -EFAULT;
825 :
826 0 : ts64->tv_sec = ts.tv_sec;
827 0 : ts64->tv_nsec = ts.tv_nsec;
828 :
829 : return 0;
830 : }
831 :
832 : static int __put_old_timespec32(const struct timespec64 *ts64,
833 : struct old_timespec32 __user *cts)
834 : {
835 0 : struct old_timespec32 ts = {
836 0 : .tv_sec = ts64->tv_sec,
837 0 : .tv_nsec = ts64->tv_nsec
838 : };
839 0 : return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0;
840 : }
841 :
842 0 : 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 0 : return __get_old_timespec32(ts, uts);
848 : }
849 : EXPORT_SYMBOL_GPL(get_old_timespec32);
850 :
851 0 : 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 0 : return __put_old_timespec32(ts, uts);
857 : }
858 : EXPORT_SYMBOL_GPL(put_old_timespec32);
859 :
860 0 : int get_itimerspec64(struct itimerspec64 *it,
861 : const struct __kernel_itimerspec __user *uit)
862 : {
863 : int ret;
864 :
865 0 : ret = get_timespec64(&it->it_interval, &uit->it_interval);
866 0 : if (ret)
867 : return ret;
868 :
869 0 : ret = get_timespec64(&it->it_value, &uit->it_value);
870 :
871 0 : return ret;
872 : }
873 : EXPORT_SYMBOL_GPL(get_itimerspec64);
874 :
875 0 : int put_itimerspec64(const struct itimerspec64 *it,
876 : struct __kernel_itimerspec __user *uit)
877 : {
878 : int ret;
879 :
880 0 : ret = put_timespec64(&it->it_interval, &uit->it_interval);
881 0 : if (ret)
882 : return ret;
883 :
884 0 : ret = put_timespec64(&it->it_value, &uit->it_value);
885 :
886 0 : return ret;
887 : }
888 : EXPORT_SYMBOL_GPL(put_itimerspec64);
889 :
890 0 : int get_old_itimerspec32(struct itimerspec64 *its,
891 : const struct old_itimerspec32 __user *uits)
892 : {
893 :
894 0 : if (__get_old_timespec32(&its->it_interval, &uits->it_interval) ||
895 0 : __get_old_timespec32(&its->it_value, &uits->it_value))
896 : return -EFAULT;
897 : return 0;
898 : }
899 : EXPORT_SYMBOL_GPL(get_old_itimerspec32);
900 :
901 0 : int put_old_itimerspec32(const struct itimerspec64 *its,
902 : struct old_itimerspec32 __user *uits)
903 : {
904 0 : if (__put_old_timespec32(&its->it_interval, &uits->it_interval) ||
905 0 : __put_old_timespec32(&its->it_value, &uits->it_value))
906 : return -EFAULT;
907 : return 0;
908 : }
909 : EXPORT_SYMBOL_GPL(put_old_itimerspec32);
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