Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/kernel/time.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
6 | * This file contains the interface functions for the various | |
7 | * time related system calls: time, stime, gettimeofday, settimeofday, | |
8 | * adjtime | |
9 | */ | |
10 | /* | |
11 | * Modification history kernel/time.c | |
6fa6c3b1 | 12 | * |
1da177e4 | 13 | * 1993-09-02 Philip Gladstone |
0a0fca9d | 14 | * Created file with time related functions from sched/core.c and adjtimex() |
1da177e4 LT |
15 | * 1993-10-08 Torsten Duwe |
16 | * adjtime interface update and CMOS clock write code | |
17 | * 1995-08-13 Torsten Duwe | |
18 | * kernel PLL updated to 1994-12-13 specs (rfc-1589) | |
19 | * 1999-01-16 Ulrich Windl | |
20 | * Introduced error checking for many cases in adjtimex(). | |
21 | * Updated NTP code according to technical memorandum Jan '96 | |
22 | * "A Kernel Model for Precision Timekeeping" by Dave Mills | |
23 | * Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10) | |
24 | * (Even though the technical memorandum forbids it) | |
25 | * 2004-07-14 Christoph Lameter | |
26 | * Added getnstimeofday to allow the posix timer functions to return | |
27 | * with nanosecond accuracy | |
28 | */ | |
29 | ||
9984de1a | 30 | #include <linux/export.h> |
abcbcb80 | 31 | #include <linux/kernel.h> |
1da177e4 | 32 | #include <linux/timex.h> |
c59ede7b | 33 | #include <linux/capability.h> |
189374ae | 34 | #include <linux/timekeeper_internal.h> |
1da177e4 | 35 | #include <linux/errno.h> |
1da177e4 LT |
36 | #include <linux/syscalls.h> |
37 | #include <linux/security.h> | |
38 | #include <linux/fs.h> | |
71abb3af | 39 | #include <linux/math64.h> |
e3d5a27d | 40 | #include <linux/ptrace.h> |
1da177e4 | 41 | |
7c0f6ba6 | 42 | #include <linux/uaccess.h> |
3a4d44b6 | 43 | #include <linux/compat.h> |
1da177e4 LT |
44 | #include <asm/unistd.h> |
45 | ||
0a227985 | 46 | #include <generated/timeconst.h> |
8b094cd0 | 47 | #include "timekeeping.h" |
bdc80787 | 48 | |
6fa6c3b1 | 49 | /* |
1da177e4 LT |
50 | * The timezone where the local system is located. Used as a default by some |
51 | * programs who obtain this value by using gettimeofday. | |
52 | */ | |
53 | struct timezone sys_tz; | |
54 | ||
55 | EXPORT_SYMBOL(sys_tz); | |
56 | ||
57 | #ifdef __ARCH_WANT_SYS_TIME | |
58 | ||
59 | /* | |
60 | * sys_time() can be implemented in user-level using | |
61 | * sys_gettimeofday(). Is this for backwards compatibility? If so, | |
62 | * why not move it into the appropriate arch directory (for those | |
63 | * architectures that need it). | |
64 | */ | |
58fd3aa2 | 65 | SYSCALL_DEFINE1(time, time_t __user *, tloc) |
1da177e4 | 66 | { |
f5a89295 | 67 | time_t i = (time_t)ktime_get_real_seconds(); |
1da177e4 LT |
68 | |
69 | if (tloc) { | |
20082208 | 70 | if (put_user(i,tloc)) |
e3d5a27d | 71 | return -EFAULT; |
1da177e4 | 72 | } |
e3d5a27d | 73 | force_successful_syscall_return(); |
1da177e4 LT |
74 | return i; |
75 | } | |
76 | ||
77 | /* | |
78 | * sys_stime() can be implemented in user-level using | |
79 | * sys_settimeofday(). Is this for backwards compatibility? If so, | |
80 | * why not move it into the appropriate arch directory (for those | |
81 | * architectures that need it). | |
82 | */ | |
6fa6c3b1 | 83 | |
58fd3aa2 | 84 | SYSCALL_DEFINE1(stime, time_t __user *, tptr) |
1da177e4 | 85 | { |
4eb1bca1 | 86 | struct timespec64 tv; |
1da177e4 LT |
87 | int err; |
88 | ||
89 | if (get_user(tv.tv_sec, tptr)) | |
90 | return -EFAULT; | |
91 | ||
92 | tv.tv_nsec = 0; | |
93 | ||
4eb1bca1 | 94 | err = security_settime64(&tv, NULL); |
1da177e4 LT |
95 | if (err) |
96 | return err; | |
97 | ||
4eb1bca1 | 98 | do_settimeofday64(&tv); |
1da177e4 LT |
99 | return 0; |
100 | } | |
101 | ||
102 | #endif /* __ARCH_WANT_SYS_TIME */ | |
103 | ||
b180db2c AV |
104 | #ifdef CONFIG_COMPAT |
105 | #ifdef __ARCH_WANT_COMPAT_SYS_TIME | |
106 | ||
107 | /* compat_time_t is a 32 bit "long" and needs to get converted. */ | |
108 | COMPAT_SYSCALL_DEFINE1(time, compat_time_t __user *, tloc) | |
109 | { | |
b180db2c AV |
110 | compat_time_t i; |
111 | ||
f5a89295 | 112 | i = (compat_time_t)ktime_get_real_seconds(); |
b180db2c AV |
113 | |
114 | if (tloc) { | |
115 | if (put_user(i,tloc)) | |
116 | return -EFAULT; | |
117 | } | |
118 | force_successful_syscall_return(); | |
119 | return i; | |
120 | } | |
121 | ||
122 | COMPAT_SYSCALL_DEFINE1(stime, compat_time_t __user *, tptr) | |
123 | { | |
4eb1bca1 | 124 | struct timespec64 tv; |
b180db2c AV |
125 | int err; |
126 | ||
127 | if (get_user(tv.tv_sec, tptr)) | |
128 | return -EFAULT; | |
129 | ||
130 | tv.tv_nsec = 0; | |
131 | ||
4eb1bca1 | 132 | err = security_settime64(&tv, NULL); |
b180db2c AV |
133 | if (err) |
134 | return err; | |
135 | ||
4eb1bca1 | 136 | do_settimeofday64(&tv); |
b180db2c AV |
137 | return 0; |
138 | } | |
139 | ||
140 | #endif /* __ARCH_WANT_COMPAT_SYS_TIME */ | |
141 | #endif | |
142 | ||
58fd3aa2 HC |
143 | SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv, |
144 | struct timezone __user *, tz) | |
1da177e4 LT |
145 | { |
146 | if (likely(tv != NULL)) { | |
147 | struct timeval ktv; | |
148 | do_gettimeofday(&ktv); | |
149 | if (copy_to_user(tv, &ktv, sizeof(ktv))) | |
150 | return -EFAULT; | |
151 | } | |
152 | if (unlikely(tz != NULL)) { | |
153 | if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) | |
154 | return -EFAULT; | |
155 | } | |
156 | return 0; | |
157 | } | |
158 | ||
1da177e4 LT |
159 | /* |
160 | * In case for some reason the CMOS clock has not already been running | |
161 | * in UTC, but in some local time: The first time we set the timezone, | |
162 | * we will warp the clock so that it is ticking UTC time instead of | |
163 | * local time. Presumably, if someone is setting the timezone then we | |
164 | * are running in an environment where the programs understand about | |
165 | * timezones. This should be done at boot time in the /etc/rc script, | |
166 | * as soon as possible, so that the clock can be set right. Otherwise, | |
167 | * various programs will get confused when the clock gets warped. | |
168 | */ | |
169 | ||
86d34732 | 170 | int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz) |
1da177e4 LT |
171 | { |
172 | static int firsttime = 1; | |
173 | int error = 0; | |
174 | ||
86d34732 | 175 | if (tv && !timespec64_valid(tv)) |
718bcceb TG |
176 | return -EINVAL; |
177 | ||
86d34732 | 178 | error = security_settime64(tv, tz); |
1da177e4 LT |
179 | if (error) |
180 | return error; | |
181 | ||
182 | if (tz) { | |
6f7d7984 SL |
183 | /* Verify we're witin the +-15 hrs range */ |
184 | if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60) | |
185 | return -EINVAL; | |
186 | ||
1da177e4 | 187 | sys_tz = *tz; |
2c622148 | 188 | update_vsyscall_tz(); |
1da177e4 LT |
189 | if (firsttime) { |
190 | firsttime = 0; | |
191 | if (!tv) | |
e0956dcc | 192 | timekeeping_warp_clock(); |
1da177e4 LT |
193 | } |
194 | } | |
195 | if (tv) | |
86d34732 | 196 | return do_settimeofday64(tv); |
1da177e4 LT |
197 | return 0; |
198 | } | |
199 | ||
58fd3aa2 HC |
200 | SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv, |
201 | struct timezone __user *, tz) | |
1da177e4 | 202 | { |
2ac00f17 | 203 | struct timespec64 new_ts; |
1da177e4 | 204 | struct timeval user_tv; |
1da177e4 LT |
205 | struct timezone new_tz; |
206 | ||
207 | if (tv) { | |
208 | if (copy_from_user(&user_tv, tv, sizeof(*tv))) | |
209 | return -EFAULT; | |
6ada1fc0 SL |
210 | |
211 | if (!timeval_valid(&user_tv)) | |
212 | return -EINVAL; | |
213 | ||
1da177e4 LT |
214 | new_ts.tv_sec = user_tv.tv_sec; |
215 | new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; | |
216 | } | |
217 | if (tz) { | |
218 | if (copy_from_user(&new_tz, tz, sizeof(*tz))) | |
219 | return -EFAULT; | |
220 | } | |
221 | ||
2ac00f17 | 222 | return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); |
1da177e4 LT |
223 | } |
224 | ||
2b2d0285 AV |
225 | #ifdef CONFIG_COMPAT |
226 | COMPAT_SYSCALL_DEFINE2(gettimeofday, struct compat_timeval __user *, tv, | |
227 | struct timezone __user *, tz) | |
228 | { | |
229 | if (tv) { | |
230 | struct timeval ktv; | |
231 | ||
232 | do_gettimeofday(&ktv); | |
233 | if (compat_put_timeval(&ktv, tv)) | |
234 | return -EFAULT; | |
235 | } | |
236 | if (tz) { | |
237 | if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) | |
238 | return -EFAULT; | |
239 | } | |
240 | ||
241 | return 0; | |
242 | } | |
243 | ||
244 | COMPAT_SYSCALL_DEFINE2(settimeofday, struct compat_timeval __user *, tv, | |
245 | struct timezone __user *, tz) | |
246 | { | |
247 | struct timespec64 new_ts; | |
248 | struct timeval user_tv; | |
249 | struct timezone new_tz; | |
250 | ||
251 | if (tv) { | |
252 | if (compat_get_timeval(&user_tv, tv)) | |
253 | return -EFAULT; | |
254 | new_ts.tv_sec = user_tv.tv_sec; | |
255 | new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; | |
256 | } | |
257 | if (tz) { | |
258 | if (copy_from_user(&new_tz, tz, sizeof(*tz))) | |
259 | return -EFAULT; | |
260 | } | |
261 | ||
262 | return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); | |
263 | } | |
264 | #endif | |
265 | ||
58fd3aa2 | 266 | SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p) |
1da177e4 LT |
267 | { |
268 | struct timex txc; /* Local copy of parameter */ | |
269 | int ret; | |
270 | ||
271 | /* Copy the user data space into the kernel copy | |
272 | * structure. But bear in mind that the structures | |
273 | * may change | |
274 | */ | |
3a4d44b6 | 275 | if (copy_from_user(&txc, txc_p, sizeof(struct timex))) |
1da177e4 LT |
276 | return -EFAULT; |
277 | ret = do_adjtimex(&txc); | |
278 | return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret; | |
279 | } | |
280 | ||
3a4d44b6 AV |
281 | #ifdef CONFIG_COMPAT |
282 | ||
283 | COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp) | |
284 | { | |
285 | struct timex txc; | |
286 | int err, ret; | |
287 | ||
288 | err = compat_get_timex(&txc, utp); | |
289 | if (err) | |
290 | return err; | |
291 | ||
292 | ret = do_adjtimex(&txc); | |
293 | ||
294 | err = compat_put_timex(utp, &txc); | |
295 | if (err) | |
296 | return err; | |
297 | ||
298 | return ret; | |
299 | } | |
300 | #endif | |
301 | ||
753e9c5c ED |
302 | /* |
303 | * Convert jiffies to milliseconds and back. | |
304 | * | |
305 | * Avoid unnecessary multiplications/divisions in the | |
306 | * two most common HZ cases: | |
307 | */ | |
af3b5628 | 308 | unsigned int jiffies_to_msecs(const unsigned long j) |
753e9c5c ED |
309 | { |
310 | #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) | |
311 | return (MSEC_PER_SEC / HZ) * j; | |
312 | #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) | |
313 | return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); | |
314 | #else | |
bdc80787 | 315 | # if BITS_PER_LONG == 32 |
abcbcb80 GU |
316 | return (HZ_TO_MSEC_MUL32 * j + (1ULL << HZ_TO_MSEC_SHR32) - 1) >> |
317 | HZ_TO_MSEC_SHR32; | |
bdc80787 | 318 | # else |
abcbcb80 | 319 | return DIV_ROUND_UP(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); |
bdc80787 | 320 | # endif |
753e9c5c ED |
321 | #endif |
322 | } | |
323 | EXPORT_SYMBOL(jiffies_to_msecs); | |
324 | ||
af3b5628 | 325 | unsigned int jiffies_to_usecs(const unsigned long j) |
753e9c5c | 326 | { |
e0758676 FW |
327 | /* |
328 | * Hz usually doesn't go much further MSEC_PER_SEC. | |
329 | * jiffies_to_usecs() and usecs_to_jiffies() depend on that. | |
330 | */ | |
331 | BUILD_BUG_ON(HZ > USEC_PER_SEC); | |
332 | ||
333 | #if !(USEC_PER_SEC % HZ) | |
753e9c5c | 334 | return (USEC_PER_SEC / HZ) * j; |
753e9c5c | 335 | #else |
bdc80787 | 336 | # if BITS_PER_LONG == 32 |
b9095fd8 | 337 | return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; |
bdc80787 PA |
338 | # else |
339 | return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; | |
340 | # endif | |
753e9c5c ED |
341 | #endif |
342 | } | |
343 | EXPORT_SYMBOL(jiffies_to_usecs); | |
344 | ||
1da177e4 | 345 | /** |
8ba8e95e | 346 | * timespec_trunc - Truncate timespec to a granularity |
1da177e4 | 347 | * @t: Timespec |
8ba8e95e | 348 | * @gran: Granularity in ns. |
1da177e4 | 349 | * |
de4a95fa KB |
350 | * Truncate a timespec to a granularity. Always rounds down. gran must |
351 | * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns). | |
1da177e4 LT |
352 | */ |
353 | struct timespec timespec_trunc(struct timespec t, unsigned gran) | |
354 | { | |
de4a95fa KB |
355 | /* Avoid division in the common cases 1 ns and 1 s. */ |
356 | if (gran == 1) { | |
1da177e4 | 357 | /* nothing */ |
de4a95fa | 358 | } else if (gran == NSEC_PER_SEC) { |
1da177e4 | 359 | t.tv_nsec = 0; |
de4a95fa | 360 | } else if (gran > 1 && gran < NSEC_PER_SEC) { |
1da177e4 | 361 | t.tv_nsec -= t.tv_nsec % gran; |
de4a95fa KB |
362 | } else { |
363 | WARN(1, "illegal file time granularity: %u", gran); | |
1da177e4 LT |
364 | } |
365 | return t; | |
366 | } | |
367 | EXPORT_SYMBOL(timespec_trunc); | |
368 | ||
90b6ce9c | 369 | /* |
370 | * mktime64 - Converts date to seconds. | |
371 | * Converts Gregorian date to seconds since 1970-01-01 00:00:00. | |
753be622 TG |
372 | * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 |
373 | * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. | |
374 | * | |
375 | * [For the Julian calendar (which was used in Russia before 1917, | |
376 | * Britain & colonies before 1752, anywhere else before 1582, | |
377 | * and is still in use by some communities) leave out the | |
378 | * -year/100+year/400 terms, and add 10.] | |
379 | * | |
380 | * This algorithm was first published by Gauss (I think). | |
ede5147d DH |
381 | * |
382 | * A leap second can be indicated by calling this function with sec as | |
383 | * 60 (allowable under ISO 8601). The leap second is treated the same | |
384 | * as the following second since they don't exist in UNIX time. | |
385 | * | |
386 | * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight | |
387 | * tomorrow - (allowable under ISO 8601) is supported. | |
753be622 | 388 | */ |
90b6ce9c | 389 | time64_t mktime64(const unsigned int year0, const unsigned int mon0, |
390 | const unsigned int day, const unsigned int hour, | |
391 | const unsigned int min, const unsigned int sec) | |
753be622 | 392 | { |
f4818900 IM |
393 | unsigned int mon = mon0, year = year0; |
394 | ||
395 | /* 1..12 -> 11,12,1..10 */ | |
396 | if (0 >= (int) (mon -= 2)) { | |
397 | mon += 12; /* Puts Feb last since it has leap day */ | |
753be622 TG |
398 | year -= 1; |
399 | } | |
400 | ||
90b6ce9c | 401 | return ((((time64_t) |
753be622 TG |
402 | (year/4 - year/100 + year/400 + 367*mon/12 + day) + |
403 | year*365 - 719499 | |
ede5147d | 404 | )*24 + hour /* now have hours - midnight tomorrow handled here */ |
753be622 TG |
405 | )*60 + min /* now have minutes */ |
406 | )*60 + sec; /* finally seconds */ | |
407 | } | |
90b6ce9c | 408 | EXPORT_SYMBOL(mktime64); |
199e7056 | 409 | |
753be622 TG |
410 | /** |
411 | * set_normalized_timespec - set timespec sec and nsec parts and normalize | |
412 | * | |
413 | * @ts: pointer to timespec variable to be set | |
414 | * @sec: seconds to set | |
415 | * @nsec: nanoseconds to set | |
416 | * | |
417 | * Set seconds and nanoseconds field of a timespec variable and | |
418 | * normalize to the timespec storage format | |
419 | * | |
420 | * Note: The tv_nsec part is always in the range of | |
bdc80787 | 421 | * 0 <= tv_nsec < NSEC_PER_SEC |
753be622 TG |
422 | * For negative values only the tv_sec field is negative ! |
423 | */ | |
12e09337 | 424 | void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec) |
753be622 TG |
425 | { |
426 | while (nsec >= NSEC_PER_SEC) { | |
12e09337 TG |
427 | /* |
428 | * The following asm() prevents the compiler from | |
429 | * optimising this loop into a modulo operation. See | |
430 | * also __iter_div_u64_rem() in include/linux/time.h | |
431 | */ | |
432 | asm("" : "+rm"(nsec)); | |
753be622 TG |
433 | nsec -= NSEC_PER_SEC; |
434 | ++sec; | |
435 | } | |
436 | while (nsec < 0) { | |
12e09337 | 437 | asm("" : "+rm"(nsec)); |
753be622 TG |
438 | nsec += NSEC_PER_SEC; |
439 | --sec; | |
440 | } | |
441 | ts->tv_sec = sec; | |
442 | ts->tv_nsec = nsec; | |
443 | } | |
7c3f944e | 444 | EXPORT_SYMBOL(set_normalized_timespec); |
753be622 | 445 | |
f8f46da3 TG |
446 | /** |
447 | * ns_to_timespec - Convert nanoseconds to timespec | |
448 | * @nsec: the nanoseconds value to be converted | |
449 | * | |
450 | * Returns the timespec representation of the nsec parameter. | |
451 | */ | |
df869b63 | 452 | struct timespec ns_to_timespec(const s64 nsec) |
f8f46da3 TG |
453 | { |
454 | struct timespec ts; | |
f8bd2258 | 455 | s32 rem; |
f8f46da3 | 456 | |
88fc3897 GA |
457 | if (!nsec) |
458 | return (struct timespec) {0, 0}; | |
459 | ||
f8bd2258 RZ |
460 | ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); |
461 | if (unlikely(rem < 0)) { | |
462 | ts.tv_sec--; | |
463 | rem += NSEC_PER_SEC; | |
464 | } | |
465 | ts.tv_nsec = rem; | |
f8f46da3 TG |
466 | |
467 | return ts; | |
468 | } | |
85795d64 | 469 | EXPORT_SYMBOL(ns_to_timespec); |
f8f46da3 TG |
470 | |
471 | /** | |
472 | * ns_to_timeval - Convert nanoseconds to timeval | |
473 | * @nsec: the nanoseconds value to be converted | |
474 | * | |
475 | * Returns the timeval representation of the nsec parameter. | |
476 | */ | |
df869b63 | 477 | struct timeval ns_to_timeval(const s64 nsec) |
f8f46da3 TG |
478 | { |
479 | struct timespec ts = ns_to_timespec(nsec); | |
480 | struct timeval tv; | |
481 | ||
482 | tv.tv_sec = ts.tv_sec; | |
483 | tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000; | |
484 | ||
485 | return tv; | |
486 | } | |
b7aa0bf7 | 487 | EXPORT_SYMBOL(ns_to_timeval); |
f8f46da3 | 488 | |
a84d1169 AB |
489 | struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec) |
490 | { | |
491 | struct timespec64 ts = ns_to_timespec64(nsec); | |
492 | struct __kernel_old_timeval tv; | |
493 | ||
494 | tv.tv_sec = ts.tv_sec; | |
495 | tv.tv_usec = (suseconds_t)ts.tv_nsec / 1000; | |
496 | ||
497 | return tv; | |
498 | } | |
499 | EXPORT_SYMBOL(ns_to_kernel_old_timeval); | |
500 | ||
49cd6f86 JS |
501 | /** |
502 | * set_normalized_timespec - set timespec sec and nsec parts and normalize | |
503 | * | |
504 | * @ts: pointer to timespec variable to be set | |
505 | * @sec: seconds to set | |
506 | * @nsec: nanoseconds to set | |
507 | * | |
508 | * Set seconds and nanoseconds field of a timespec variable and | |
509 | * normalize to the timespec storage format | |
510 | * | |
511 | * Note: The tv_nsec part is always in the range of | |
512 | * 0 <= tv_nsec < NSEC_PER_SEC | |
513 | * For negative values only the tv_sec field is negative ! | |
514 | */ | |
515 | void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec) | |
516 | { | |
517 | while (nsec >= NSEC_PER_SEC) { | |
518 | /* | |
519 | * The following asm() prevents the compiler from | |
520 | * optimising this loop into a modulo operation. See | |
521 | * also __iter_div_u64_rem() in include/linux/time.h | |
522 | */ | |
523 | asm("" : "+rm"(nsec)); | |
524 | nsec -= NSEC_PER_SEC; | |
525 | ++sec; | |
526 | } | |
527 | while (nsec < 0) { | |
528 | asm("" : "+rm"(nsec)); | |
529 | nsec += NSEC_PER_SEC; | |
530 | --sec; | |
531 | } | |
532 | ts->tv_sec = sec; | |
533 | ts->tv_nsec = nsec; | |
534 | } | |
535 | EXPORT_SYMBOL(set_normalized_timespec64); | |
536 | ||
537 | /** | |
538 | * ns_to_timespec64 - Convert nanoseconds to timespec64 | |
539 | * @nsec: the nanoseconds value to be converted | |
540 | * | |
541 | * Returns the timespec64 representation of the nsec parameter. | |
542 | */ | |
543 | struct timespec64 ns_to_timespec64(const s64 nsec) | |
544 | { | |
545 | struct timespec64 ts; | |
546 | s32 rem; | |
547 | ||
548 | if (!nsec) | |
549 | return (struct timespec64) {0, 0}; | |
550 | ||
551 | ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); | |
552 | if (unlikely(rem < 0)) { | |
553 | ts.tv_sec--; | |
554 | rem += NSEC_PER_SEC; | |
555 | } | |
556 | ts.tv_nsec = rem; | |
557 | ||
558 | return ts; | |
559 | } | |
560 | EXPORT_SYMBOL(ns_to_timespec64); | |
abc8f96e | 561 | |
ca42aaf0 NMG |
562 | /** |
563 | * msecs_to_jiffies: - convert milliseconds to jiffies | |
564 | * @m: time in milliseconds | |
565 | * | |
566 | * conversion is done as follows: | |
41cf5445 IM |
567 | * |
568 | * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) | |
569 | * | |
570 | * - 'too large' values [that would result in larger than | |
571 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. | |
572 | * | |
573 | * - all other values are converted to jiffies by either multiplying | |
ca42aaf0 NMG |
574 | * the input value by a factor or dividing it with a factor and |
575 | * handling any 32-bit overflows. | |
576 | * for the details see __msecs_to_jiffies() | |
41cf5445 | 577 | * |
ca42aaf0 NMG |
578 | * msecs_to_jiffies() checks for the passed in value being a constant |
579 | * via __builtin_constant_p() allowing gcc to eliminate most of the | |
580 | * code, __msecs_to_jiffies() is called if the value passed does not | |
581 | * allow constant folding and the actual conversion must be done at | |
582 | * runtime. | |
583 | * the _msecs_to_jiffies helpers are the HZ dependent conversion | |
584 | * routines found in include/linux/jiffies.h | |
41cf5445 | 585 | */ |
ca42aaf0 | 586 | unsigned long __msecs_to_jiffies(const unsigned int m) |
8b9365d7 | 587 | { |
41cf5445 IM |
588 | /* |
589 | * Negative value, means infinite timeout: | |
590 | */ | |
591 | if ((int)m < 0) | |
8b9365d7 | 592 | return MAX_JIFFY_OFFSET; |
ca42aaf0 | 593 | return _msecs_to_jiffies(m); |
8b9365d7 | 594 | } |
ca42aaf0 | 595 | EXPORT_SYMBOL(__msecs_to_jiffies); |
8b9365d7 | 596 | |
ae60d6a0 | 597 | unsigned long __usecs_to_jiffies(const unsigned int u) |
8b9365d7 IM |
598 | { |
599 | if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) | |
600 | return MAX_JIFFY_OFFSET; | |
ae60d6a0 | 601 | return _usecs_to_jiffies(u); |
8b9365d7 | 602 | } |
ae60d6a0 | 603 | EXPORT_SYMBOL(__usecs_to_jiffies); |
8b9365d7 IM |
604 | |
605 | /* | |
606 | * The TICK_NSEC - 1 rounds up the value to the next resolution. Note | |
607 | * that a remainder subtract here would not do the right thing as the | |
608 | * resolution values don't fall on second boundries. I.e. the line: | |
609 | * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding. | |
d78c9300 AH |
610 | * Note that due to the small error in the multiplier here, this |
611 | * rounding is incorrect for sufficiently large values of tv_nsec, but | |
612 | * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're | |
613 | * OK. | |
8b9365d7 IM |
614 | * |
615 | * Rather, we just shift the bits off the right. | |
616 | * | |
617 | * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec | |
618 | * value to a scaled second value. | |
619 | */ | |
d78c9300 | 620 | static unsigned long |
9ca30850 | 621 | __timespec64_to_jiffies(u64 sec, long nsec) |
8b9365d7 | 622 | { |
d78c9300 | 623 | nsec = nsec + TICK_NSEC - 1; |
8b9365d7 IM |
624 | |
625 | if (sec >= MAX_SEC_IN_JIFFIES){ | |
626 | sec = MAX_SEC_IN_JIFFIES; | |
627 | nsec = 0; | |
628 | } | |
9ca30850 | 629 | return ((sec * SEC_CONVERSION) + |
8b9365d7 IM |
630 | (((u64)nsec * NSEC_CONVERSION) >> |
631 | (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; | |
632 | ||
633 | } | |
d78c9300 | 634 | |
9ca30850 BW |
635 | static unsigned long |
636 | __timespec_to_jiffies(unsigned long sec, long nsec) | |
d78c9300 | 637 | { |
9ca30850 | 638 | return __timespec64_to_jiffies((u64)sec, nsec); |
d78c9300 AH |
639 | } |
640 | ||
9ca30850 BW |
641 | unsigned long |
642 | timespec64_to_jiffies(const struct timespec64 *value) | |
643 | { | |
644 | return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec); | |
645 | } | |
646 | EXPORT_SYMBOL(timespec64_to_jiffies); | |
8b9365d7 IM |
647 | |
648 | void | |
9ca30850 | 649 | jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value) |
8b9365d7 IM |
650 | { |
651 | /* | |
652 | * Convert jiffies to nanoseconds and separate with | |
653 | * one divide. | |
654 | */ | |
f8bd2258 RZ |
655 | u32 rem; |
656 | value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, | |
657 | NSEC_PER_SEC, &rem); | |
658 | value->tv_nsec = rem; | |
8b9365d7 | 659 | } |
9ca30850 | 660 | EXPORT_SYMBOL(jiffies_to_timespec64); |
8b9365d7 | 661 | |
d78c9300 AH |
662 | /* |
663 | * We could use a similar algorithm to timespec_to_jiffies (with a | |
664 | * different multiplier for usec instead of nsec). But this has a | |
665 | * problem with rounding: we can't exactly add TICK_NSEC - 1 to the | |
666 | * usec value, since it's not necessarily integral. | |
667 | * | |
668 | * We could instead round in the intermediate scaled representation | |
669 | * (i.e. in units of 1/2^(large scale) jiffies) but that's also | |
670 | * perilous: the scaling introduces a small positive error, which | |
671 | * combined with a division-rounding-upward (i.e. adding 2^(scale) - 1 | |
672 | * units to the intermediate before shifting) leads to accidental | |
673 | * overflow and overestimates. | |
8b9365d7 | 674 | * |
d78c9300 AH |
675 | * At the cost of one additional multiplication by a constant, just |
676 | * use the timespec implementation. | |
8b9365d7 IM |
677 | */ |
678 | unsigned long | |
679 | timeval_to_jiffies(const struct timeval *value) | |
680 | { | |
d78c9300 AH |
681 | return __timespec_to_jiffies(value->tv_sec, |
682 | value->tv_usec * NSEC_PER_USEC); | |
8b9365d7 | 683 | } |
456a09dc | 684 | EXPORT_SYMBOL(timeval_to_jiffies); |
8b9365d7 IM |
685 | |
686 | void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value) | |
687 | { | |
688 | /* | |
689 | * Convert jiffies to nanoseconds and separate with | |
690 | * one divide. | |
691 | */ | |
f8bd2258 | 692 | u32 rem; |
8b9365d7 | 693 | |
f8bd2258 RZ |
694 | value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, |
695 | NSEC_PER_SEC, &rem); | |
696 | value->tv_usec = rem / NSEC_PER_USEC; | |
8b9365d7 | 697 | } |
456a09dc | 698 | EXPORT_SYMBOL(jiffies_to_timeval); |
8b9365d7 IM |
699 | |
700 | /* | |
701 | * Convert jiffies/jiffies_64 to clock_t and back. | |
702 | */ | |
cbbc719f | 703 | clock_t jiffies_to_clock_t(unsigned long x) |
8b9365d7 IM |
704 | { |
705 | #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 | |
6ffc787a DF |
706 | # if HZ < USER_HZ |
707 | return x * (USER_HZ / HZ); | |
708 | # else | |
8b9365d7 | 709 | return x / (HZ / USER_HZ); |
6ffc787a | 710 | # endif |
8b9365d7 | 711 | #else |
71abb3af | 712 | return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ); |
8b9365d7 IM |
713 | #endif |
714 | } | |
715 | EXPORT_SYMBOL(jiffies_to_clock_t); | |
716 | ||
717 | unsigned long clock_t_to_jiffies(unsigned long x) | |
718 | { | |
719 | #if (HZ % USER_HZ)==0 | |
720 | if (x >= ~0UL / (HZ / USER_HZ)) | |
721 | return ~0UL; | |
722 | return x * (HZ / USER_HZ); | |
723 | #else | |
8b9365d7 IM |
724 | /* Don't worry about loss of precision here .. */ |
725 | if (x >= ~0UL / HZ * USER_HZ) | |
726 | return ~0UL; | |
727 | ||
728 | /* .. but do try to contain it here */ | |
71abb3af | 729 | return div_u64((u64)x * HZ, USER_HZ); |
8b9365d7 IM |
730 | #endif |
731 | } | |
732 | EXPORT_SYMBOL(clock_t_to_jiffies); | |
733 | ||
734 | u64 jiffies_64_to_clock_t(u64 x) | |
735 | { | |
736 | #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 | |
6ffc787a | 737 | # if HZ < USER_HZ |
71abb3af | 738 | x = div_u64(x * USER_HZ, HZ); |
ec03d707 | 739 | # elif HZ > USER_HZ |
71abb3af | 740 | x = div_u64(x, HZ / USER_HZ); |
ec03d707 AM |
741 | # else |
742 | /* Nothing to do */ | |
6ffc787a | 743 | # endif |
8b9365d7 IM |
744 | #else |
745 | /* | |
746 | * There are better ways that don't overflow early, | |
747 | * but even this doesn't overflow in hundreds of years | |
748 | * in 64 bits, so.. | |
749 | */ | |
71abb3af | 750 | x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ)); |
8b9365d7 IM |
751 | #endif |
752 | return x; | |
753 | } | |
8b9365d7 IM |
754 | EXPORT_SYMBOL(jiffies_64_to_clock_t); |
755 | ||
756 | u64 nsec_to_clock_t(u64 x) | |
757 | { | |
758 | #if (NSEC_PER_SEC % USER_HZ) == 0 | |
71abb3af | 759 | return div_u64(x, NSEC_PER_SEC / USER_HZ); |
8b9365d7 | 760 | #elif (USER_HZ % 512) == 0 |
71abb3af | 761 | return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512); |
8b9365d7 IM |
762 | #else |
763 | /* | |
764 | * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024, | |
765 | * overflow after 64.99 years. | |
766 | * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ... | |
767 | */ | |
71abb3af | 768 | return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ); |
8b9365d7 | 769 | #endif |
8b9365d7 IM |
770 | } |
771 | ||
07e5f5e3 FW |
772 | u64 jiffies64_to_nsecs(u64 j) |
773 | { | |
774 | #if !(NSEC_PER_SEC % HZ) | |
775 | return (NSEC_PER_SEC / HZ) * j; | |
776 | # else | |
777 | return div_u64(j * HZ_TO_NSEC_NUM, HZ_TO_NSEC_DEN); | |
778 | #endif | |
779 | } | |
780 | EXPORT_SYMBOL(jiffies64_to_nsecs); | |
781 | ||
b7b20df9 | 782 | /** |
a1dabb6b | 783 | * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 |
b7b20df9 HS |
784 | * |
785 | * @n: nsecs in u64 | |
786 | * | |
787 | * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. | |
788 | * And this doesn't return MAX_JIFFY_OFFSET since this function is designed | |
789 | * for scheduler, not for use in device drivers to calculate timeout value. | |
790 | * | |
791 | * note: | |
792 | * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) | |
793 | * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years | |
794 | */ | |
a1dabb6b | 795 | u64 nsecs_to_jiffies64(u64 n) |
b7b20df9 HS |
796 | { |
797 | #if (NSEC_PER_SEC % HZ) == 0 | |
798 | /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ | |
799 | return div_u64(n, NSEC_PER_SEC / HZ); | |
800 | #elif (HZ % 512) == 0 | |
801 | /* overflow after 292 years if HZ = 1024 */ | |
802 | return div_u64(n * HZ / 512, NSEC_PER_SEC / 512); | |
803 | #else | |
804 | /* | |
805 | * Generic case - optimized for cases where HZ is a multiple of 3. | |
806 | * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc. | |
807 | */ | |
808 | return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); | |
809 | #endif | |
810 | } | |
7bd0e226 | 811 | EXPORT_SYMBOL(nsecs_to_jiffies64); |
b7b20df9 | 812 | |
a1dabb6b VP |
813 | /** |
814 | * nsecs_to_jiffies - Convert nsecs in u64 to jiffies | |
815 | * | |
816 | * @n: nsecs in u64 | |
817 | * | |
818 | * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. | |
819 | * And this doesn't return MAX_JIFFY_OFFSET since this function is designed | |
820 | * for scheduler, not for use in device drivers to calculate timeout value. | |
821 | * | |
822 | * note: | |
823 | * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) | |
824 | * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years | |
825 | */ | |
826 | unsigned long nsecs_to_jiffies(u64 n) | |
827 | { | |
828 | return (unsigned long)nsecs_to_jiffies64(n); | |
829 | } | |
d560fed6 | 830 | EXPORT_SYMBOL_GPL(nsecs_to_jiffies); |
a1dabb6b | 831 | |
bc2c53e5 DD |
832 | /* |
833 | * Add two timespec64 values and do a safety check for overflow. | |
834 | * It's assumed that both values are valid (>= 0). | |
835 | * And, each timespec64 is in normalized form. | |
836 | */ | |
837 | struct timespec64 timespec64_add_safe(const struct timespec64 lhs, | |
838 | const struct timespec64 rhs) | |
839 | { | |
840 | struct timespec64 res; | |
841 | ||
469e857f | 842 | set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec, |
bc2c53e5 DD |
843 | lhs.tv_nsec + rhs.tv_nsec); |
844 | ||
845 | if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) { | |
846 | res.tv_sec = TIME64_MAX; | |
847 | res.tv_nsec = 0; | |
848 | } | |
849 | ||
850 | return res; | |
851 | } | |
f59dd9c8 DD |
852 | |
853 | int get_timespec64(struct timespec64 *ts, | |
ea2ce8f3 | 854 | const struct __kernel_timespec __user *uts) |
f59dd9c8 | 855 | { |
ea2ce8f3 | 856 | struct __kernel_timespec kts; |
f59dd9c8 DD |
857 | int ret; |
858 | ||
859 | ret = copy_from_user(&kts, uts, sizeof(kts)); | |
860 | if (ret) | |
861 | return -EFAULT; | |
862 | ||
863 | ts->tv_sec = kts.tv_sec; | |
ea2ce8f3 DD |
864 | |
865 | /* Zero out the padding for 32 bit systems or in compat mode */ | |
866 | if (IS_ENABLED(CONFIG_64BIT_TIME) && (!IS_ENABLED(CONFIG_64BIT) || in_compat_syscall())) | |
867 | kts.tv_nsec &= 0xFFFFFFFFUL; | |
868 | ||
f59dd9c8 DD |
869 | ts->tv_nsec = kts.tv_nsec; |
870 | ||
871 | return 0; | |
872 | } | |
873 | EXPORT_SYMBOL_GPL(get_timespec64); | |
874 | ||
875 | int put_timespec64(const struct timespec64 *ts, | |
ea2ce8f3 | 876 | struct __kernel_timespec __user *uts) |
f59dd9c8 | 877 | { |
ea2ce8f3 | 878 | struct __kernel_timespec kts = { |
f59dd9c8 DD |
879 | .tv_sec = ts->tv_sec, |
880 | .tv_nsec = ts->tv_nsec | |
881 | }; | |
ea2ce8f3 | 882 | |
f59dd9c8 DD |
883 | return copy_to_user(uts, &kts, sizeof(kts)) ? -EFAULT : 0; |
884 | } | |
885 | EXPORT_SYMBOL_GPL(put_timespec64); | |
d5b7ffbf | 886 | |
1c68adf6 DD |
887 | int __compat_get_timespec64(struct timespec64 *ts64, |
888 | const struct compat_timespec __user *cts) | |
889 | { | |
890 | struct compat_timespec ts; | |
891 | int ret; | |
892 | ||
893 | ret = copy_from_user(&ts, cts, sizeof(ts)); | |
894 | if (ret) | |
895 | return -EFAULT; | |
896 | ||
897 | ts64->tv_sec = ts.tv_sec; | |
898 | ts64->tv_nsec = ts.tv_nsec; | |
899 | ||
900 | return 0; | |
901 | } | |
902 | ||
903 | int __compat_put_timespec64(const struct timespec64 *ts64, | |
904 | struct compat_timespec __user *cts) | |
905 | { | |
906 | struct compat_timespec ts = { | |
907 | .tv_sec = ts64->tv_sec, | |
908 | .tv_nsec = ts64->tv_nsec | |
909 | }; | |
910 | return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0; | |
911 | } | |
912 | ||
913 | int compat_get_timespec64(struct timespec64 *ts, const void __user *uts) | |
914 | { | |
915 | if (COMPAT_USE_64BIT_TIME) | |
916 | return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; | |
917 | else | |
918 | return __compat_get_timespec64(ts, uts); | |
919 | } | |
920 | EXPORT_SYMBOL_GPL(compat_get_timespec64); | |
921 | ||
922 | int compat_put_timespec64(const struct timespec64 *ts, void __user *uts) | |
923 | { | |
924 | if (COMPAT_USE_64BIT_TIME) | |
925 | return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; | |
926 | else | |
927 | return __compat_put_timespec64(ts, uts); | |
928 | } | |
929 | EXPORT_SYMBOL_GPL(compat_put_timespec64); | |
930 | ||
d5b7ffbf | 931 | int get_itimerspec64(struct itimerspec64 *it, |
d0dd63a8 | 932 | const struct __kernel_itimerspec __user *uit) |
d5b7ffbf DD |
933 | { |
934 | int ret; | |
935 | ||
936 | ret = get_timespec64(&it->it_interval, &uit->it_interval); | |
937 | if (ret) | |
938 | return ret; | |
939 | ||
940 | ret = get_timespec64(&it->it_value, &uit->it_value); | |
941 | ||
942 | return ret; | |
943 | } | |
944 | EXPORT_SYMBOL_GPL(get_itimerspec64); | |
945 | ||
946 | int put_itimerspec64(const struct itimerspec64 *it, | |
d0dd63a8 | 947 | struct __kernel_itimerspec __user *uit) |
d5b7ffbf DD |
948 | { |
949 | int ret; | |
950 | ||
951 | ret = put_timespec64(&it->it_interval, &uit->it_interval); | |
952 | if (ret) | |
953 | return ret; | |
954 | ||
955 | ret = put_timespec64(&it->it_value, &uit->it_value); | |
956 | ||
957 | return ret; | |
958 | } | |
959 | EXPORT_SYMBOL_GPL(put_itimerspec64); | |
afef05cf DD |
960 | |
961 | int get_compat_itimerspec64(struct itimerspec64 *its, | |
962 | const struct compat_itimerspec __user *uits) | |
963 | { | |
964 | ||
965 | if (__compat_get_timespec64(&its->it_interval, &uits->it_interval) || | |
966 | __compat_get_timespec64(&its->it_value, &uits->it_value)) | |
967 | return -EFAULT; | |
968 | return 0; | |
969 | } | |
970 | EXPORT_SYMBOL_GPL(get_compat_itimerspec64); | |
971 | ||
972 | int put_compat_itimerspec64(const struct itimerspec64 *its, | |
973 | struct compat_itimerspec __user *uits) | |
974 | { | |
975 | if (__compat_put_timespec64(&its->it_interval, &uits->it_interval) || | |
976 | __compat_put_timespec64(&its->it_value, &uits->it_value)) | |
977 | return -EFAULT; | |
978 | return 0; | |
979 | } | |
980 | EXPORT_SYMBOL_GPL(put_compat_itimerspec64); |