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 | 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 | |
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(ts: &tv, NULL); |
92 | if (err) |
93 | return err; |
94 | |
95 | do_settimeofday64(ts: &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. */ |
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(ts: &tv, NULL); |
130 | if (err) |
131 | return err; |
132 | |
133 | do_settimeofday64(ts: &tv); |
134 | return 0; |
135 | } |
136 | |
137 | #endif /* __ARCH_WANT_SYS_TIME32 */ |
138 | #endif |
139 | |
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(tv: &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(to: tz, from: &sys_tz, n: 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 | 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(ts: tv)) |
175 | return -EINVAL; |
176 | |
177 | error = security_settime64(ts: 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(ts: tv); |
196 | return 0; |
197 | } |
198 | |
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(to: &new_tz, from: tz, n: sizeof(*tz))) |
217 | return -EFAULT; |
218 | } |
219 | |
220 | return do_sys_settimeofday64(tv: tv ? &new_ts : NULL, tz: 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(tv: &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(to: tz, from: &sys_tz, n: 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(to: &new_tz, from: tz, n: sizeof(*tz))) |
261 | return -EFAULT; |
262 | } |
263 | |
264 | return do_sys_settimeofday64(tv: tv ? &new_ts : NULL, tz: tz ? &new_tz : NULL); |
265 | } |
266 | #endif |
267 | |
268 | #ifdef CONFIG_64BIT |
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(to: &txc, from: txc_p, n: sizeof(struct __kernel_timex))) |
279 | return -EFAULT; |
280 | ret = do_adjtimex(&txc); |
281 | return copy_to_user(to: txc_p, from: &txc, n: 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(to: &tx32, from: utp, n: 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(to: utp, from: &tx32, n: 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: &txc, utp); |
355 | if (err) |
356 | return err; |
357 | |
358 | ret = do_adjtimex(&txc); |
359 | |
360 | err = put_old_timex32(utp, txc: &txc); |
361 | if (err) |
362 | return err; |
363 | |
364 | return ret; |
365 | } |
366 | #endif |
367 | |
368 | /** |
369 | * jiffies_to_msecs - Convert jiffies to milliseconds |
370 | * @j: jiffies value |
371 | * |
372 | * Avoid unnecessary multiplications/divisions in the |
373 | * two most common HZ cases. |
374 | * |
375 | * Return: milliseconds value |
376 | */ |
377 | unsigned int jiffies_to_msecs(const unsigned long j) |
378 | { |
379 | #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) |
380 | return (MSEC_PER_SEC / HZ) * j; |
381 | #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) |
382 | return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); |
383 | #else |
384 | # if BITS_PER_LONG == 32 |
385 | return (HZ_TO_MSEC_MUL32 * j + (1ULL << HZ_TO_MSEC_SHR32) - 1) >> |
386 | HZ_TO_MSEC_SHR32; |
387 | # else |
388 | return DIV_ROUND_UP(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); |
389 | # endif |
390 | #endif |
391 | } |
392 | EXPORT_SYMBOL(jiffies_to_msecs); |
393 | |
394 | /** |
395 | * jiffies_to_usecs - Convert jiffies to microseconds |
396 | * @j: jiffies value |
397 | * |
398 | * Return: microseconds value |
399 | */ |
400 | unsigned int jiffies_to_usecs(const unsigned long j) |
401 | { |
402 | /* |
403 | * Hz usually doesn't go much further MSEC_PER_SEC. |
404 | * jiffies_to_usecs() and usecs_to_jiffies() depend on that. |
405 | */ |
406 | BUILD_BUG_ON(HZ > USEC_PER_SEC); |
407 | |
408 | #if !(USEC_PER_SEC % HZ) |
409 | return (USEC_PER_SEC / HZ) * j; |
410 | #else |
411 | # if BITS_PER_LONG == 32 |
412 | return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; |
413 | # else |
414 | return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; |
415 | # endif |
416 | #endif |
417 | } |
418 | EXPORT_SYMBOL(jiffies_to_usecs); |
419 | |
420 | /** |
421 | * mktime64 - Converts date to seconds. |
422 | * @year0: year to convert |
423 | * @mon0: month to convert |
424 | * @day: day to convert |
425 | * @hour: hour to convert |
426 | * @min: minute to convert |
427 | * @sec: second to convert |
428 | * |
429 | * Converts Gregorian date to seconds since 1970-01-01 00:00:00. |
430 | * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 |
431 | * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. |
432 | * |
433 | * [For the Julian calendar (which was used in Russia before 1917, |
434 | * Britain & colonies before 1752, anywhere else before 1582, |
435 | * and is still in use by some communities) leave out the |
436 | * -year/100+year/400 terms, and add 10.] |
437 | * |
438 | * This algorithm was first published by Gauss (I think). |
439 | * |
440 | * A leap second can be indicated by calling this function with sec as |
441 | * 60 (allowable under ISO 8601). The leap second is treated the same |
442 | * as the following second since they don't exist in UNIX time. |
443 | * |
444 | * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight |
445 | * tomorrow - (allowable under ISO 8601) is supported. |
446 | * |
447 | * Return: seconds since the epoch time for the given input date |
448 | */ |
449 | time64_t mktime64(const unsigned int year0, const unsigned int mon0, |
450 | const unsigned int day, const unsigned int hour, |
451 | const unsigned int min, const unsigned int sec) |
452 | { |
453 | unsigned int mon = mon0, year = year0; |
454 | |
455 | /* 1..12 -> 11,12,1..10 */ |
456 | if (0 >= (int) (mon -= 2)) { |
457 | mon += 12; /* Puts Feb last since it has leap day */ |
458 | year -= 1; |
459 | } |
460 | |
461 | return ((((time64_t) |
462 | (year/4 - year/100 + year/400 + 367*mon/12 + day) + |
463 | year*365 - 719499 |
464 | )*24 + hour /* now have hours - midnight tomorrow handled here */ |
465 | )*60 + min /* now have minutes */ |
466 | )*60 + sec; /* finally seconds */ |
467 | } |
468 | EXPORT_SYMBOL(mktime64); |
469 | |
470 | struct __kernel_old_timeval ns_to_kernel_old_timeval(s64 nsec) |
471 | { |
472 | struct timespec64 ts = ns_to_timespec64(nsec); |
473 | struct __kernel_old_timeval tv; |
474 | |
475 | tv.tv_sec = ts.tv_sec; |
476 | tv.tv_usec = (suseconds_t)ts.tv_nsec / 1000; |
477 | |
478 | return tv; |
479 | } |
480 | EXPORT_SYMBOL(ns_to_kernel_old_timeval); |
481 | |
482 | /** |
483 | * set_normalized_timespec64 - set timespec sec and nsec parts and normalize |
484 | * |
485 | * @ts: pointer to timespec variable to be set |
486 | * @sec: seconds to set |
487 | * @nsec: nanoseconds to set |
488 | * |
489 | * Set seconds and nanoseconds field of a timespec variable and |
490 | * normalize to the timespec storage format |
491 | * |
492 | * Note: The tv_nsec part is always in the range of 0 <= tv_nsec < NSEC_PER_SEC. |
493 | * For negative values only the tv_sec field is negative ! |
494 | */ |
495 | void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec) |
496 | { |
497 | while (nsec >= NSEC_PER_SEC) { |
498 | /* |
499 | * The following asm() prevents the compiler from |
500 | * optimising this loop into a modulo operation. See |
501 | * also __iter_div_u64_rem() in include/linux/time.h |
502 | */ |
503 | asm("" : "+rm" (nsec)); |
504 | nsec -= NSEC_PER_SEC; |
505 | ++sec; |
506 | } |
507 | while (nsec < 0) { |
508 | asm("" : "+rm" (nsec)); |
509 | nsec += NSEC_PER_SEC; |
510 | --sec; |
511 | } |
512 | ts->tv_sec = sec; |
513 | ts->tv_nsec = nsec; |
514 | } |
515 | EXPORT_SYMBOL(set_normalized_timespec64); |
516 | |
517 | /** |
518 | * ns_to_timespec64 - Convert nanoseconds to timespec64 |
519 | * @nsec: the nanoseconds value to be converted |
520 | * |
521 | * Return: the timespec64 representation of the nsec parameter. |
522 | */ |
523 | struct timespec64 ns_to_timespec64(s64 nsec) |
524 | { |
525 | struct timespec64 ts = { 0, 0 }; |
526 | s32 rem; |
527 | |
528 | if (likely(nsec > 0)) { |
529 | ts.tv_sec = div_u64_rem(dividend: nsec, NSEC_PER_SEC, remainder: &rem); |
530 | ts.tv_nsec = rem; |
531 | } else if (nsec < 0) { |
532 | /* |
533 | * With negative times, tv_sec points to the earlier |
534 | * second, and tv_nsec counts the nanoseconds since |
535 | * then, so tv_nsec is always a positive number. |
536 | */ |
537 | ts.tv_sec = -div_u64_rem(dividend: -nsec - 1, NSEC_PER_SEC, remainder: &rem) - 1; |
538 | ts.tv_nsec = NSEC_PER_SEC - rem - 1; |
539 | } |
540 | |
541 | return ts; |
542 | } |
543 | EXPORT_SYMBOL(ns_to_timespec64); |
544 | |
545 | /** |
546 | * __msecs_to_jiffies: - convert milliseconds to jiffies |
547 | * @m: time in milliseconds |
548 | * |
549 | * conversion is done as follows: |
550 | * |
551 | * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) |
552 | * |
553 | * - 'too large' values [that would result in larger than |
554 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. |
555 | * |
556 | * - all other values are converted to jiffies by either multiplying |
557 | * the input value by a factor or dividing it with a factor and |
558 | * handling any 32-bit overflows. |
559 | * for the details see __msecs_to_jiffies() |
560 | * |
561 | * __msecs_to_jiffies() checks for the passed in value being a constant |
562 | * via __builtin_constant_p() allowing gcc to eliminate most of the |
563 | * code, __msecs_to_jiffies() is called if the value passed does not |
564 | * allow constant folding and the actual conversion must be done at |
565 | * runtime. |
566 | * The _msecs_to_jiffies helpers are the HZ dependent conversion |
567 | * routines found in include/linux/jiffies.h |
568 | * |
569 | * Return: jiffies value |
570 | */ |
571 | unsigned long __msecs_to_jiffies(const unsigned int m) |
572 | { |
573 | /* |
574 | * Negative value, means infinite timeout: |
575 | */ |
576 | if ((int)m < 0) |
577 | return MAX_JIFFY_OFFSET; |
578 | return _msecs_to_jiffies(m); |
579 | } |
580 | EXPORT_SYMBOL(__msecs_to_jiffies); |
581 | |
582 | /** |
583 | * __usecs_to_jiffies: - convert microseconds to jiffies |
584 | * @u: time in milliseconds |
585 | * |
586 | * Return: jiffies value |
587 | */ |
588 | unsigned long __usecs_to_jiffies(const unsigned int u) |
589 | { |
590 | if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) |
591 | return MAX_JIFFY_OFFSET; |
592 | return _usecs_to_jiffies(u); |
593 | } |
594 | EXPORT_SYMBOL(__usecs_to_jiffies); |
595 | |
596 | /** |
597 | * timespec64_to_jiffies - convert a timespec64 value to jiffies |
598 | * @value: pointer to &struct timespec64 |
599 | * |
600 | * The TICK_NSEC - 1 rounds up the value to the next resolution. Note |
601 | * that a remainder subtract here would not do the right thing as the |
602 | * resolution values don't fall on second boundaries. I.e. the line: |
603 | * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding. |
604 | * Note that due to the small error in the multiplier here, this |
605 | * rounding is incorrect for sufficiently large values of tv_nsec, but |
606 | * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're |
607 | * OK. |
608 | * |
609 | * Rather, we just shift the bits off the right. |
610 | * |
611 | * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec |
612 | * value to a scaled second value. |
613 | * |
614 | * Return: jiffies value |
615 | */ |
616 | unsigned long |
617 | timespec64_to_jiffies(const struct timespec64 *value) |
618 | { |
619 | u64 sec = value->tv_sec; |
620 | long nsec = value->tv_nsec + TICK_NSEC - 1; |
621 | |
622 | if (sec >= MAX_SEC_IN_JIFFIES){ |
623 | sec = MAX_SEC_IN_JIFFIES; |
624 | nsec = 0; |
625 | } |
626 | return ((sec * SEC_CONVERSION) + |
627 | (((u64)nsec * NSEC_CONVERSION) >> |
628 | (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; |
629 | |
630 | } |
631 | EXPORT_SYMBOL(timespec64_to_jiffies); |
632 | |
633 | /** |
634 | * jiffies_to_timespec64 - convert jiffies value to &struct timespec64 |
635 | * @jiffies: jiffies value |
636 | * @value: pointer to &struct timespec64 |
637 | */ |
638 | void |
639 | jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value) |
640 | { |
641 | /* |
642 | * Convert jiffies to nanoseconds and separate with |
643 | * one divide. |
644 | */ |
645 | u32 rem; |
646 | value->tv_sec = div_u64_rem(dividend: (u64)jiffies * TICK_NSEC, |
647 | NSEC_PER_SEC, remainder: &rem); |
648 | value->tv_nsec = rem; |
649 | } |
650 | EXPORT_SYMBOL(jiffies_to_timespec64); |
651 | |
652 | /* |
653 | * Convert jiffies/jiffies_64 to clock_t and back. |
654 | */ |
655 | |
656 | /** |
657 | * jiffies_to_clock_t - Convert jiffies to clock_t |
658 | * @x: jiffies value |
659 | * |
660 | * Return: jiffies converted to clock_t (CLOCKS_PER_SEC) |
661 | */ |
662 | clock_t jiffies_to_clock_t(unsigned long x) |
663 | { |
664 | #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 |
665 | # if HZ < USER_HZ |
666 | return x * (USER_HZ / HZ); |
667 | # else |
668 | return x / (HZ / USER_HZ); |
669 | # endif |
670 | #else |
671 | return div_u64(dividend: (u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ); |
672 | #endif |
673 | } |
674 | EXPORT_SYMBOL(jiffies_to_clock_t); |
675 | |
676 | /** |
677 | * clock_t_to_jiffies - Convert clock_t to jiffies |
678 | * @x: clock_t value |
679 | * |
680 | * Return: clock_t value converted to jiffies |
681 | */ |
682 | unsigned long clock_t_to_jiffies(unsigned long x) |
683 | { |
684 | #if (HZ % USER_HZ)==0 |
685 | if (x >= ~0UL / (HZ / USER_HZ)) |
686 | return ~0UL; |
687 | return x * (HZ / USER_HZ); |
688 | #else |
689 | /* Don't worry about loss of precision here .. */ |
690 | if (x >= ~0UL / HZ * USER_HZ) |
691 | return ~0UL; |
692 | |
693 | /* .. but do try to contain it here */ |
694 | return div_u64(dividend: (u64)x * HZ, USER_HZ); |
695 | #endif |
696 | } |
697 | EXPORT_SYMBOL(clock_t_to_jiffies); |
698 | |
699 | /** |
700 | * jiffies_64_to_clock_t - Convert jiffies_64 to clock_t |
701 | * @x: jiffies_64 value |
702 | * |
703 | * Return: jiffies_64 value converted to 64-bit "clock_t" (CLOCKS_PER_SEC) |
704 | */ |
705 | u64 jiffies_64_to_clock_t(u64 x) |
706 | { |
707 | #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 |
708 | # if HZ < USER_HZ |
709 | x = div_u64(x * USER_HZ, HZ); |
710 | # elif HZ > USER_HZ |
711 | x = div_u64(x, HZ / USER_HZ); |
712 | # else |
713 | /* Nothing to do */ |
714 | # endif |
715 | #else |
716 | /* |
717 | * There are better ways that don't overflow early, |
718 | * but even this doesn't overflow in hundreds of years |
719 | * in 64 bits, so.. |
720 | */ |
721 | x = div_u64(dividend: x * TICK_NSEC, divisor: (NSEC_PER_SEC / USER_HZ)); |
722 | #endif |
723 | return x; |
724 | } |
725 | EXPORT_SYMBOL(jiffies_64_to_clock_t); |
726 | |
727 | /** |
728 | * nsec_to_clock_t - Convert nsec value to clock_t |
729 | * @x: nsec value |
730 | * |
731 | * Return: nsec value converted to 64-bit "clock_t" (CLOCKS_PER_SEC) |
732 | */ |
733 | u64 nsec_to_clock_t(u64 x) |
734 | { |
735 | #if (NSEC_PER_SEC % USER_HZ) == 0 |
736 | return div_u64(dividend: x, NSEC_PER_SEC / USER_HZ); |
737 | #elif (USER_HZ % 512) == 0 |
738 | return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512); |
739 | #else |
740 | /* |
741 | * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024, |
742 | * overflow after 64.99 years. |
743 | * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ... |
744 | */ |
745 | return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ); |
746 | #endif |
747 | } |
748 | |
749 | /** |
750 | * jiffies64_to_nsecs - Convert jiffies64 to nanoseconds |
751 | * @j: jiffies64 value |
752 | * |
753 | * Return: nanoseconds value |
754 | */ |
755 | u64 jiffies64_to_nsecs(u64 j) |
756 | { |
757 | #if !(NSEC_PER_SEC % HZ) |
758 | return (NSEC_PER_SEC / HZ) * j; |
759 | # else |
760 | return div_u64(j * HZ_TO_NSEC_NUM, HZ_TO_NSEC_DEN); |
761 | #endif |
762 | } |
763 | EXPORT_SYMBOL(jiffies64_to_nsecs); |
764 | |
765 | /** |
766 | * jiffies64_to_msecs - Convert jiffies64 to milliseconds |
767 | * @j: jiffies64 value |
768 | * |
769 | * Return: milliseconds value |
770 | */ |
771 | u64 jiffies64_to_msecs(const u64 j) |
772 | { |
773 | #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) |
774 | return (MSEC_PER_SEC / HZ) * j; |
775 | #else |
776 | return div_u64(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); |
777 | #endif |
778 | } |
779 | EXPORT_SYMBOL(jiffies64_to_msecs); |
780 | |
781 | /** |
782 | * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 |
783 | * |
784 | * @n: nsecs in u64 |
785 | * |
786 | * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. |
787 | * And this doesn't return MAX_JIFFY_OFFSET since this function is designed |
788 | * for scheduler, not for use in device drivers to calculate timeout value. |
789 | * |
790 | * note: |
791 | * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) |
792 | * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years |
793 | * |
794 | * Return: nsecs converted to jiffies64 value |
795 | */ |
796 | u64 nsecs_to_jiffies64(u64 n) |
797 | { |
798 | #if (NSEC_PER_SEC % HZ) == 0 |
799 | /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ |
800 | return div_u64(dividend: n, NSEC_PER_SEC / HZ); |
801 | #elif (HZ % 512) == 0 |
802 | /* overflow after 292 years if HZ = 1024 */ |
803 | return div_u64(n * HZ / 512, NSEC_PER_SEC / 512); |
804 | #else |
805 | /* |
806 | * Generic case - optimized for cases where HZ is a multiple of 3. |
807 | * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc. |
808 | */ |
809 | return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); |
810 | #endif |
811 | } |
812 | EXPORT_SYMBOL(nsecs_to_jiffies64); |
813 | |
814 | /** |
815 | * nsecs_to_jiffies - Convert nsecs in u64 to jiffies |
816 | * |
817 | * @n: nsecs in u64 |
818 | * |
819 | * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. |
820 | * And this doesn't return MAX_JIFFY_OFFSET since this function is designed |
821 | * for scheduler, not for use in device drivers to calculate timeout value. |
822 | * |
823 | * note: |
824 | * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) |
825 | * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years |
826 | * |
827 | * Return: nsecs converted to jiffies value |
828 | */ |
829 | unsigned long nsecs_to_jiffies(u64 n) |
830 | { |
831 | return (unsigned long)nsecs_to_jiffies64(n); |
832 | } |
833 | EXPORT_SYMBOL_GPL(nsecs_to_jiffies); |
834 | |
835 | /** |
836 | * timespec64_add_safe - Add two timespec64 values and do a safety check |
837 | * for overflow. |
838 | * @lhs: first (left) timespec64 to add |
839 | * @rhs: second (right) timespec64 to add |
840 | * |
841 | * It's assumed that both values are valid (>= 0). |
842 | * And, each timespec64 is in normalized form. |
843 | * |
844 | * Return: sum of @lhs + @rhs |
845 | */ |
846 | struct timespec64 timespec64_add_safe(const struct timespec64 lhs, |
847 | const struct timespec64 rhs) |
848 | { |
849 | struct timespec64 res; |
850 | |
851 | set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec, |
852 | lhs.tv_nsec + rhs.tv_nsec); |
853 | |
854 | if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) { |
855 | res.tv_sec = TIME64_MAX; |
856 | res.tv_nsec = 0; |
857 | } |
858 | |
859 | return res; |
860 | } |
861 | |
862 | /** |
863 | * get_timespec64 - get user's time value into kernel space |
864 | * @ts: destination &struct timespec64 |
865 | * @uts: user's time value as &struct __kernel_timespec |
866 | * |
867 | * Handles compat or 32-bit modes. |
868 | * |
869 | * Return: %0 on success or negative errno on error |
870 | */ |
871 | int get_timespec64(struct timespec64 *ts, |
872 | const struct __kernel_timespec __user *uts) |
873 | { |
874 | struct __kernel_timespec kts; |
875 | int ret; |
876 | |
877 | ret = copy_from_user(to: &kts, from: uts, n: sizeof(kts)); |
878 | if (ret) |
879 | return -EFAULT; |
880 | |
881 | ts->tv_sec = kts.tv_sec; |
882 | |
883 | /* Zero out the padding in compat mode */ |
884 | if (in_compat_syscall()) |
885 | kts.tv_nsec &= 0xFFFFFFFFUL; |
886 | |
887 | /* In 32-bit mode, this drops the padding */ |
888 | ts->tv_nsec = kts.tv_nsec; |
889 | |
890 | return 0; |
891 | } |
892 | EXPORT_SYMBOL_GPL(get_timespec64); |
893 | |
894 | /** |
895 | * put_timespec64 - convert timespec64 value to __kernel_timespec format and |
896 | * copy the latter to userspace |
897 | * @ts: input &struct timespec64 |
898 | * @uts: user's &struct __kernel_timespec |
899 | * |
900 | * Return: %0 on success or negative errno on error |
901 | */ |
902 | int put_timespec64(const struct timespec64 *ts, |
903 | struct __kernel_timespec __user *uts) |
904 | { |
905 | struct __kernel_timespec kts = { |
906 | .tv_sec = ts->tv_sec, |
907 | .tv_nsec = ts->tv_nsec |
908 | }; |
909 | |
910 | return copy_to_user(to: uts, from: &kts, n: sizeof(kts)) ? -EFAULT : 0; |
911 | } |
912 | EXPORT_SYMBOL_GPL(put_timespec64); |
913 | |
914 | static int __get_old_timespec32(struct timespec64 *ts64, |
915 | const struct old_timespec32 __user *cts) |
916 | { |
917 | struct old_timespec32 ts; |
918 | int ret; |
919 | |
920 | ret = copy_from_user(to: &ts, from: cts, n: sizeof(ts)); |
921 | if (ret) |
922 | return -EFAULT; |
923 | |
924 | ts64->tv_sec = ts.tv_sec; |
925 | ts64->tv_nsec = ts.tv_nsec; |
926 | |
927 | return 0; |
928 | } |
929 | |
930 | static int __put_old_timespec32(const struct timespec64 *ts64, |
931 | struct old_timespec32 __user *cts) |
932 | { |
933 | struct old_timespec32 ts = { |
934 | .tv_sec = ts64->tv_sec, |
935 | .tv_nsec = ts64->tv_nsec |
936 | }; |
937 | return copy_to_user(to: cts, from: &ts, n: sizeof(ts)) ? -EFAULT : 0; |
938 | } |
939 | |
940 | /** |
941 | * get_old_timespec32 - get user's old-format time value into kernel space |
942 | * @ts: destination &struct timespec64 |
943 | * @uts: user's old-format time value (&struct old_timespec32) |
944 | * |
945 | * Handles X86_X32_ABI compatibility conversion. |
946 | * |
947 | * Return: %0 on success or negative errno on error |
948 | */ |
949 | int get_old_timespec32(struct timespec64 *ts, const void __user *uts) |
950 | { |
951 | if (COMPAT_USE_64BIT_TIME) |
952 | return copy_from_user(to: ts, from: uts, n: sizeof(*ts)) ? -EFAULT : 0; |
953 | else |
954 | return __get_old_timespec32(ts64: ts, cts: uts); |
955 | } |
956 | EXPORT_SYMBOL_GPL(get_old_timespec32); |
957 | |
958 | /** |
959 | * put_old_timespec32 - convert timespec64 value to &struct old_timespec32 and |
960 | * copy the latter to userspace |
961 | * @ts: input &struct timespec64 |
962 | * @uts: user's &struct old_timespec32 |
963 | * |
964 | * Handles X86_X32_ABI compatibility conversion. |
965 | * |
966 | * Return: %0 on success or negative errno on error |
967 | */ |
968 | int put_old_timespec32(const struct timespec64 *ts, void __user *uts) |
969 | { |
970 | if (COMPAT_USE_64BIT_TIME) |
971 | return copy_to_user(to: uts, from: ts, n: sizeof(*ts)) ? -EFAULT : 0; |
972 | else |
973 | return __put_old_timespec32(ts64: ts, cts: uts); |
974 | } |
975 | EXPORT_SYMBOL_GPL(put_old_timespec32); |
976 | |
977 | /** |
978 | * get_itimerspec64 - get user's &struct __kernel_itimerspec into kernel space |
979 | * @it: destination &struct itimerspec64 |
980 | * @uit: user's &struct __kernel_itimerspec |
981 | * |
982 | * Return: %0 on success or negative errno on error |
983 | */ |
984 | int get_itimerspec64(struct itimerspec64 *it, |
985 | const struct __kernel_itimerspec __user *uit) |
986 | { |
987 | int ret; |
988 | |
989 | ret = get_timespec64(&it->it_interval, &uit->it_interval); |
990 | if (ret) |
991 | return ret; |
992 | |
993 | ret = get_timespec64(&it->it_value, &uit->it_value); |
994 | |
995 | return ret; |
996 | } |
997 | EXPORT_SYMBOL_GPL(get_itimerspec64); |
998 | |
999 | /** |
1000 | * put_itimerspec64 - convert &struct itimerspec64 to __kernel_itimerspec format |
1001 | * and copy the latter to userspace |
1002 | * @it: input &struct itimerspec64 |
1003 | * @uit: user's &struct __kernel_itimerspec |
1004 | * |
1005 | * Return: %0 on success or negative errno on error |
1006 | */ |
1007 | int put_itimerspec64(const struct itimerspec64 *it, |
1008 | struct __kernel_itimerspec __user *uit) |
1009 | { |
1010 | int ret; |
1011 | |
1012 | ret = put_timespec64(&it->it_interval, &uit->it_interval); |
1013 | if (ret) |
1014 | return ret; |
1015 | |
1016 | ret = put_timespec64(&it->it_value, &uit->it_value); |
1017 | |
1018 | return ret; |
1019 | } |
1020 | EXPORT_SYMBOL_GPL(put_itimerspec64); |
1021 | |
1022 | /** |
1023 | * get_old_itimerspec32 - get user's &struct old_itimerspec32 into kernel space |
1024 | * @its: destination &struct itimerspec64 |
1025 | * @uits: user's &struct old_itimerspec32 |
1026 | * |
1027 | * Return: %0 on success or negative errno on error |
1028 | */ |
1029 | int get_old_itimerspec32(struct itimerspec64 *its, |
1030 | const struct old_itimerspec32 __user *uits) |
1031 | { |
1032 | |
1033 | if (__get_old_timespec32(ts64: &its->it_interval, cts: &uits->it_interval) || |
1034 | __get_old_timespec32(ts64: &its->it_value, cts: &uits->it_value)) |
1035 | return -EFAULT; |
1036 | return 0; |
1037 | } |
1038 | EXPORT_SYMBOL_GPL(get_old_itimerspec32); |
1039 | |
1040 | /** |
1041 | * put_old_itimerspec32 - convert &struct itimerspec64 to &struct |
1042 | * old_itimerspec32 and copy the latter to userspace |
1043 | * @its: input &struct itimerspec64 |
1044 | * @uits: user's &struct old_itimerspec32 |
1045 | * |
1046 | * Return: %0 on success or negative errno on error |
1047 | */ |
1048 | int put_old_itimerspec32(const struct itimerspec64 *its, |
1049 | struct old_itimerspec32 __user *uits) |
1050 | { |
1051 | if (__put_old_timespec32(ts64: &its->it_interval, cts: &uits->it_interval) || |
1052 | __put_old_timespec32(ts64: &its->it_value, cts: &uits->it_value)) |
1053 | return -EFAULT; |
1054 | return 0; |
1055 | } |
1056 | EXPORT_SYMBOL_GPL(put_old_itimerspec32); |
1057 | |