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Commit | Line | Data |
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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 | ||
9afc5eee AB |
107 | /* old_time32_t is a 32 bit "long" and needs to get converted. */ |
108 | COMPAT_SYSCALL_DEFINE1(time, old_time32_t __user *, tloc) | |
b180db2c | 109 | { |
9afc5eee | 110 | old_time32_t i; |
b180db2c | 111 | |
9afc5eee | 112 | i = (old_time32_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 | ||
9afc5eee | 122 | COMPAT_SYSCALL_DEFINE1(stime, old_time32_t __user *, tptr) |
b180db2c | 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)) { | |
33e26418 AB |
147 | struct timespec64 ts; |
148 | ||
149 | ktime_get_real_ts64(&ts); | |
150 | if (put_user(ts.tv_sec, &tv->tv_sec) || | |
151 | put_user(ts.tv_nsec / 1000, &tv->tv_usec)) | |
1da177e4 LT |
152 | return -EFAULT; |
153 | } | |
154 | if (unlikely(tz != NULL)) { | |
155 | if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) | |
156 | return -EFAULT; | |
157 | } | |
158 | return 0; | |
159 | } | |
160 | ||
1da177e4 LT |
161 | /* |
162 | * In case for some reason the CMOS clock has not already been running | |
163 | * in UTC, but in some local time: The first time we set the timezone, | |
164 | * we will warp the clock so that it is ticking UTC time instead of | |
165 | * local time. Presumably, if someone is setting the timezone then we | |
166 | * are running in an environment where the programs understand about | |
167 | * timezones. This should be done at boot time in the /etc/rc script, | |
168 | * as soon as possible, so that the clock can be set right. Otherwise, | |
169 | * various programs will get confused when the clock gets warped. | |
170 | */ | |
171 | ||
86d34732 | 172 | int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz) |
1da177e4 LT |
173 | { |
174 | static int firsttime = 1; | |
175 | int error = 0; | |
176 | ||
86d34732 | 177 | if (tv && !timespec64_valid(tv)) |
718bcceb TG |
178 | return -EINVAL; |
179 | ||
86d34732 | 180 | error = security_settime64(tv, tz); |
1da177e4 LT |
181 | if (error) |
182 | return error; | |
183 | ||
184 | if (tz) { | |
6f7d7984 SL |
185 | /* Verify we're witin the +-15 hrs range */ |
186 | if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60) | |
187 | return -EINVAL; | |
188 | ||
1da177e4 | 189 | sys_tz = *tz; |
2c622148 | 190 | update_vsyscall_tz(); |
1da177e4 LT |
191 | if (firsttime) { |
192 | firsttime = 0; | |
193 | if (!tv) | |
e0956dcc | 194 | timekeeping_warp_clock(); |
1da177e4 LT |
195 | } |
196 | } | |
197 | if (tv) | |
86d34732 | 198 | return do_settimeofday64(tv); |
1da177e4 LT |
199 | return 0; |
200 | } | |
201 | ||
58fd3aa2 HC |
202 | SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv, |
203 | struct timezone __user *, tz) | |
1da177e4 | 204 | { |
2ac00f17 | 205 | struct timespec64 new_ts; |
1da177e4 | 206 | struct timeval user_tv; |
1da177e4 LT |
207 | struct timezone new_tz; |
208 | ||
209 | if (tv) { | |
210 | if (copy_from_user(&user_tv, tv, sizeof(*tv))) | |
211 | return -EFAULT; | |
6ada1fc0 SL |
212 | |
213 | if (!timeval_valid(&user_tv)) | |
214 | return -EINVAL; | |
215 | ||
1da177e4 LT |
216 | new_ts.tv_sec = user_tv.tv_sec; |
217 | new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; | |
218 | } | |
219 | if (tz) { | |
220 | if (copy_from_user(&new_tz, tz, sizeof(*tz))) | |
221 | return -EFAULT; | |
222 | } | |
223 | ||
2ac00f17 | 224 | return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); |
1da177e4 LT |
225 | } |
226 | ||
2b2d0285 | 227 | #ifdef CONFIG_COMPAT |
9afc5eee | 228 | COMPAT_SYSCALL_DEFINE2(gettimeofday, struct old_timeval32 __user *, tv, |
2b2d0285 AV |
229 | struct timezone __user *, tz) |
230 | { | |
231 | if (tv) { | |
33e26418 | 232 | struct timespec64 ts; |
2b2d0285 | 233 | |
33e26418 AB |
234 | ktime_get_real_ts64(&ts); |
235 | if (put_user(ts.tv_sec, &tv->tv_sec) || | |
236 | put_user(ts.tv_nsec / 1000, &tv->tv_usec)) | |
2b2d0285 AV |
237 | return -EFAULT; |
238 | } | |
239 | if (tz) { | |
240 | if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) | |
241 | return -EFAULT; | |
242 | } | |
243 | ||
244 | return 0; | |
245 | } | |
246 | ||
9afc5eee | 247 | COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv, |
2b2d0285 AV |
248 | struct timezone __user *, tz) |
249 | { | |
250 | struct timespec64 new_ts; | |
251 | struct timeval user_tv; | |
252 | struct timezone new_tz; | |
253 | ||
254 | if (tv) { | |
255 | if (compat_get_timeval(&user_tv, tv)) | |
256 | return -EFAULT; | |
257 | new_ts.tv_sec = user_tv.tv_sec; | |
258 | new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; | |
259 | } | |
260 | if (tz) { | |
261 | if (copy_from_user(&new_tz, tz, sizeof(*tz))) | |
262 | return -EFAULT; | |
263 | } | |
264 | ||
265 | return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); | |
266 | } | |
267 | #endif | |
268 | ||
58fd3aa2 | 269 | SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p) |
1da177e4 LT |
270 | { |
271 | struct 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 | */ | |
3a4d44b6 | 278 | if (copy_from_user(&txc, txc_p, sizeof(struct timex))) |
1da177e4 LT |
279 | return -EFAULT; |
280 | ret = do_adjtimex(&txc); | |
281 | return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret; | |
282 | } | |
283 | ||
3a4d44b6 AV |
284 | #ifdef CONFIG_COMPAT |
285 | ||
286 | COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp) | |
287 | { | |
288 | struct timex txc; | |
289 | int err, ret; | |
290 | ||
291 | err = compat_get_timex(&txc, utp); | |
292 | if (err) | |
293 | return err; | |
294 | ||
295 | ret = do_adjtimex(&txc); | |
296 | ||
297 | err = compat_put_timex(utp, &txc); | |
298 | if (err) | |
299 | return err; | |
300 | ||
301 | return ret; | |
302 | } | |
303 | #endif | |
304 | ||
753e9c5c ED |
305 | /* |
306 | * Convert jiffies to milliseconds and back. | |
307 | * | |
308 | * Avoid unnecessary multiplications/divisions in the | |
309 | * two most common HZ cases: | |
310 | */ | |
af3b5628 | 311 | unsigned int jiffies_to_msecs(const unsigned long j) |
753e9c5c ED |
312 | { |
313 | #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) | |
314 | return (MSEC_PER_SEC / HZ) * j; | |
315 | #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) | |
316 | return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); | |
317 | #else | |
bdc80787 | 318 | # if BITS_PER_LONG == 32 |
abcbcb80 GU |
319 | return (HZ_TO_MSEC_MUL32 * j + (1ULL << HZ_TO_MSEC_SHR32) - 1) >> |
320 | HZ_TO_MSEC_SHR32; | |
bdc80787 | 321 | # else |
abcbcb80 | 322 | return DIV_ROUND_UP(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); |
bdc80787 | 323 | # endif |
753e9c5c ED |
324 | #endif |
325 | } | |
326 | EXPORT_SYMBOL(jiffies_to_msecs); | |
327 | ||
af3b5628 | 328 | unsigned int jiffies_to_usecs(const unsigned long j) |
753e9c5c | 329 | { |
e0758676 FW |
330 | /* |
331 | * Hz usually doesn't go much further MSEC_PER_SEC. | |
332 | * jiffies_to_usecs() and usecs_to_jiffies() depend on that. | |
333 | */ | |
334 | BUILD_BUG_ON(HZ > USEC_PER_SEC); | |
335 | ||
336 | #if !(USEC_PER_SEC % HZ) | |
753e9c5c | 337 | return (USEC_PER_SEC / HZ) * j; |
753e9c5c | 338 | #else |
bdc80787 | 339 | # if BITS_PER_LONG == 32 |
b9095fd8 | 340 | return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; |
bdc80787 PA |
341 | # else |
342 | return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; | |
343 | # endif | |
753e9c5c ED |
344 | #endif |
345 | } | |
346 | EXPORT_SYMBOL(jiffies_to_usecs); | |
347 | ||
90b6ce9c | 348 | /* |
349 | * mktime64 - Converts date to seconds. | |
350 | * Converts Gregorian date to seconds since 1970-01-01 00:00:00. | |
753be622 TG |
351 | * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 |
352 | * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. | |
353 | * | |
354 | * [For the Julian calendar (which was used in Russia before 1917, | |
355 | * Britain & colonies before 1752, anywhere else before 1582, | |
356 | * and is still in use by some communities) leave out the | |
357 | * -year/100+year/400 terms, and add 10.] | |
358 | * | |
359 | * This algorithm was first published by Gauss (I think). | |
ede5147d DH |
360 | * |
361 | * A leap second can be indicated by calling this function with sec as | |
362 | * 60 (allowable under ISO 8601). The leap second is treated the same | |
363 | * as the following second since they don't exist in UNIX time. | |
364 | * | |
365 | * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight | |
366 | * tomorrow - (allowable under ISO 8601) is supported. | |
753be622 | 367 | */ |
90b6ce9c | 368 | time64_t mktime64(const unsigned int year0, const unsigned int mon0, |
369 | const unsigned int day, const unsigned int hour, | |
370 | const unsigned int min, const unsigned int sec) | |
753be622 | 371 | { |
f4818900 IM |
372 | unsigned int mon = mon0, year = year0; |
373 | ||
374 | /* 1..12 -> 11,12,1..10 */ | |
375 | if (0 >= (int) (mon -= 2)) { | |
376 | mon += 12; /* Puts Feb last since it has leap day */ | |
753be622 TG |
377 | year -= 1; |
378 | } | |
379 | ||
90b6ce9c | 380 | return ((((time64_t) |
753be622 TG |
381 | (year/4 - year/100 + year/400 + 367*mon/12 + day) + |
382 | year*365 - 719499 | |
ede5147d | 383 | )*24 + hour /* now have hours - midnight tomorrow handled here */ |
753be622 TG |
384 | )*60 + min /* now have minutes */ |
385 | )*60 + sec; /* finally seconds */ | |
386 | } | |
90b6ce9c | 387 | EXPORT_SYMBOL(mktime64); |
199e7056 | 388 | |
753be622 TG |
389 | /** |
390 | * set_normalized_timespec - set timespec sec and nsec parts and normalize | |
391 | * | |
392 | * @ts: pointer to timespec variable to be set | |
393 | * @sec: seconds to set | |
394 | * @nsec: nanoseconds to set | |
395 | * | |
396 | * Set seconds and nanoseconds field of a timespec variable and | |
397 | * normalize to the timespec storage format | |
398 | * | |
399 | * Note: The tv_nsec part is always in the range of | |
bdc80787 | 400 | * 0 <= tv_nsec < NSEC_PER_SEC |
753be622 TG |
401 | * For negative values only the tv_sec field is negative ! |
402 | */ | |
12e09337 | 403 | void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec) |
753be622 TG |
404 | { |
405 | while (nsec >= NSEC_PER_SEC) { | |
12e09337 TG |
406 | /* |
407 | * The following asm() prevents the compiler from | |
408 | * optimising this loop into a modulo operation. See | |
409 | * also __iter_div_u64_rem() in include/linux/time.h | |
410 | */ | |
411 | asm("" : "+rm"(nsec)); | |
753be622 TG |
412 | nsec -= NSEC_PER_SEC; |
413 | ++sec; | |
414 | } | |
415 | while (nsec < 0) { | |
12e09337 | 416 | asm("" : "+rm"(nsec)); |
753be622 TG |
417 | nsec += NSEC_PER_SEC; |
418 | --sec; | |
419 | } | |
420 | ts->tv_sec = sec; | |
421 | ts->tv_nsec = nsec; | |
422 | } | |
7c3f944e | 423 | EXPORT_SYMBOL(set_normalized_timespec); |
753be622 | 424 | |
f8f46da3 TG |
425 | /** |
426 | * ns_to_timespec - Convert nanoseconds to timespec | |
427 | * @nsec: the nanoseconds value to be converted | |
428 | * | |
429 | * Returns the timespec representation of the nsec parameter. | |
430 | */ | |
df869b63 | 431 | struct timespec ns_to_timespec(const s64 nsec) |
f8f46da3 TG |
432 | { |
433 | struct timespec ts; | |
f8bd2258 | 434 | s32 rem; |
f8f46da3 | 435 | |
88fc3897 GA |
436 | if (!nsec) |
437 | return (struct timespec) {0, 0}; | |
438 | ||
f8bd2258 RZ |
439 | ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); |
440 | if (unlikely(rem < 0)) { | |
441 | ts.tv_sec--; | |
442 | rem += NSEC_PER_SEC; | |
443 | } | |
444 | ts.tv_nsec = rem; | |
f8f46da3 TG |
445 | |
446 | return ts; | |
447 | } | |
85795d64 | 448 | EXPORT_SYMBOL(ns_to_timespec); |
f8f46da3 TG |
449 | |
450 | /** | |
451 | * ns_to_timeval - Convert nanoseconds to timeval | |
452 | * @nsec: the nanoseconds value to be converted | |
453 | * | |
454 | * Returns the timeval representation of the nsec parameter. | |
455 | */ | |
df869b63 | 456 | struct timeval ns_to_timeval(const s64 nsec) |
f8f46da3 TG |
457 | { |
458 | struct timespec ts = ns_to_timespec(nsec); | |
459 | struct timeval tv; | |
460 | ||
461 | tv.tv_sec = ts.tv_sec; | |
462 | tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000; | |
463 | ||
464 | return tv; | |
465 | } | |
b7aa0bf7 | 466 | EXPORT_SYMBOL(ns_to_timeval); |
f8f46da3 | 467 | |
a84d1169 AB |
468 | struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec) |
469 | { | |
470 | struct timespec64 ts = ns_to_timespec64(nsec); | |
471 | struct __kernel_old_timeval tv; | |
472 | ||
473 | tv.tv_sec = ts.tv_sec; | |
474 | tv.tv_usec = (suseconds_t)ts.tv_nsec / 1000; | |
475 | ||
476 | return tv; | |
477 | } | |
478 | EXPORT_SYMBOL(ns_to_kernel_old_timeval); | |
479 | ||
49cd6f86 JS |
480 | /** |
481 | * set_normalized_timespec - set timespec sec and nsec parts and normalize | |
482 | * | |
483 | * @ts: pointer to timespec variable to be set | |
484 | * @sec: seconds to set | |
485 | * @nsec: nanoseconds to set | |
486 | * | |
487 | * Set seconds and nanoseconds field of a timespec variable and | |
488 | * normalize to the timespec storage format | |
489 | * | |
490 | * Note: The tv_nsec part is always in the range of | |
491 | * 0 <= tv_nsec < NSEC_PER_SEC | |
492 | * For negative values only the tv_sec field is negative ! | |
493 | */ | |
494 | void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec) | |
495 | { | |
496 | while (nsec >= NSEC_PER_SEC) { | |
497 | /* | |
498 | * The following asm() prevents the compiler from | |
499 | * optimising this loop into a modulo operation. See | |
500 | * also __iter_div_u64_rem() in include/linux/time.h | |
501 | */ | |
502 | asm("" : "+rm"(nsec)); | |
503 | nsec -= NSEC_PER_SEC; | |
504 | ++sec; | |
505 | } | |
506 | while (nsec < 0) { | |
507 | asm("" : "+rm"(nsec)); | |
508 | nsec += NSEC_PER_SEC; | |
509 | --sec; | |
510 | } | |
511 | ts->tv_sec = sec; | |
512 | ts->tv_nsec = nsec; | |
513 | } | |
514 | EXPORT_SYMBOL(set_normalized_timespec64); | |
515 | ||
516 | /** | |
517 | * ns_to_timespec64 - Convert nanoseconds to timespec64 | |
518 | * @nsec: the nanoseconds value to be converted | |
519 | * | |
520 | * Returns the timespec64 representation of the nsec parameter. | |
521 | */ | |
522 | struct timespec64 ns_to_timespec64(const s64 nsec) | |
523 | { | |
524 | struct timespec64 ts; | |
525 | s32 rem; | |
526 | ||
527 | if (!nsec) | |
528 | return (struct timespec64) {0, 0}; | |
529 | ||
530 | ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); | |
531 | if (unlikely(rem < 0)) { | |
532 | ts.tv_sec--; | |
533 | rem += NSEC_PER_SEC; | |
534 | } | |
535 | ts.tv_nsec = rem; | |
536 | ||
537 | return ts; | |
538 | } | |
539 | EXPORT_SYMBOL(ns_to_timespec64); | |
abc8f96e | 540 | |
ca42aaf0 NMG |
541 | /** |
542 | * msecs_to_jiffies: - convert milliseconds to jiffies | |
543 | * @m: time in milliseconds | |
544 | * | |
545 | * conversion is done as follows: | |
41cf5445 IM |
546 | * |
547 | * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) | |
548 | * | |
549 | * - 'too large' values [that would result in larger than | |
550 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. | |
551 | * | |
552 | * - all other values are converted to jiffies by either multiplying | |
ca42aaf0 NMG |
553 | * the input value by a factor or dividing it with a factor and |
554 | * handling any 32-bit overflows. | |
555 | * for the details see __msecs_to_jiffies() | |
41cf5445 | 556 | * |
ca42aaf0 NMG |
557 | * msecs_to_jiffies() checks for the passed in value being a constant |
558 | * via __builtin_constant_p() allowing gcc to eliminate most of the | |
559 | * code, __msecs_to_jiffies() is called if the value passed does not | |
560 | * allow constant folding and the actual conversion must be done at | |
561 | * runtime. | |
562 | * the _msecs_to_jiffies helpers are the HZ dependent conversion | |
563 | * routines found in include/linux/jiffies.h | |
41cf5445 | 564 | */ |
ca42aaf0 | 565 | unsigned long __msecs_to_jiffies(const unsigned int m) |
8b9365d7 | 566 | { |
41cf5445 IM |
567 | /* |
568 | * Negative value, means infinite timeout: | |
569 | */ | |
570 | if ((int)m < 0) | |
8b9365d7 | 571 | return MAX_JIFFY_OFFSET; |
ca42aaf0 | 572 | return _msecs_to_jiffies(m); |
8b9365d7 | 573 | } |
ca42aaf0 | 574 | EXPORT_SYMBOL(__msecs_to_jiffies); |
8b9365d7 | 575 | |
ae60d6a0 | 576 | unsigned long __usecs_to_jiffies(const unsigned int u) |
8b9365d7 IM |
577 | { |
578 | if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) | |
579 | return MAX_JIFFY_OFFSET; | |
ae60d6a0 | 580 | return _usecs_to_jiffies(u); |
8b9365d7 | 581 | } |
ae60d6a0 | 582 | EXPORT_SYMBOL(__usecs_to_jiffies); |
8b9365d7 IM |
583 | |
584 | /* | |
585 | * The TICK_NSEC - 1 rounds up the value to the next resolution. Note | |
586 | * that a remainder subtract here would not do the right thing as the | |
587 | * resolution values don't fall on second boundries. I.e. the line: | |
588 | * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding. | |
d78c9300 AH |
589 | * Note that due to the small error in the multiplier here, this |
590 | * rounding is incorrect for sufficiently large values of tv_nsec, but | |
591 | * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're | |
592 | * OK. | |
8b9365d7 IM |
593 | * |
594 | * Rather, we just shift the bits off the right. | |
595 | * | |
596 | * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec | |
597 | * value to a scaled second value. | |
598 | */ | |
d78c9300 | 599 | static unsigned long |
9ca30850 | 600 | __timespec64_to_jiffies(u64 sec, long nsec) |
8b9365d7 | 601 | { |
d78c9300 | 602 | nsec = nsec + TICK_NSEC - 1; |
8b9365d7 IM |
603 | |
604 | if (sec >= MAX_SEC_IN_JIFFIES){ | |
605 | sec = MAX_SEC_IN_JIFFIES; | |
606 | nsec = 0; | |
607 | } | |
9ca30850 | 608 | return ((sec * SEC_CONVERSION) + |
8b9365d7 IM |
609 | (((u64)nsec * NSEC_CONVERSION) >> |
610 | (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; | |
611 | ||
612 | } | |
d78c9300 | 613 | |
9ca30850 BW |
614 | static unsigned long |
615 | __timespec_to_jiffies(unsigned long sec, long nsec) | |
d78c9300 | 616 | { |
9ca30850 | 617 | return __timespec64_to_jiffies((u64)sec, nsec); |
d78c9300 AH |
618 | } |
619 | ||
9ca30850 BW |
620 | unsigned long |
621 | timespec64_to_jiffies(const struct timespec64 *value) | |
622 | { | |
623 | return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec); | |
624 | } | |
625 | EXPORT_SYMBOL(timespec64_to_jiffies); | |
8b9365d7 IM |
626 | |
627 | void | |
9ca30850 | 628 | jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value) |
8b9365d7 IM |
629 | { |
630 | /* | |
631 | * Convert jiffies to nanoseconds and separate with | |
632 | * one divide. | |
633 | */ | |
f8bd2258 RZ |
634 | u32 rem; |
635 | value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, | |
636 | NSEC_PER_SEC, &rem); | |
637 | value->tv_nsec = rem; | |
8b9365d7 | 638 | } |
9ca30850 | 639 | EXPORT_SYMBOL(jiffies_to_timespec64); |
8b9365d7 | 640 | |
d78c9300 AH |
641 | /* |
642 | * We could use a similar algorithm to timespec_to_jiffies (with a | |
643 | * different multiplier for usec instead of nsec). But this has a | |
644 | * problem with rounding: we can't exactly add TICK_NSEC - 1 to the | |
645 | * usec value, since it's not necessarily integral. | |
646 | * | |
647 | * We could instead round in the intermediate scaled representation | |
648 | * (i.e. in units of 1/2^(large scale) jiffies) but that's also | |
649 | * perilous: the scaling introduces a small positive error, which | |
650 | * combined with a division-rounding-upward (i.e. adding 2^(scale) - 1 | |
651 | * units to the intermediate before shifting) leads to accidental | |
652 | * overflow and overestimates. | |
8b9365d7 | 653 | * |
d78c9300 AH |
654 | * At the cost of one additional multiplication by a constant, just |
655 | * use the timespec implementation. | |
8b9365d7 IM |
656 | */ |
657 | unsigned long | |
658 | timeval_to_jiffies(const struct timeval *value) | |
659 | { | |
d78c9300 AH |
660 | return __timespec_to_jiffies(value->tv_sec, |
661 | value->tv_usec * NSEC_PER_USEC); | |
8b9365d7 | 662 | } |
456a09dc | 663 | EXPORT_SYMBOL(timeval_to_jiffies); |
8b9365d7 IM |
664 | |
665 | void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value) | |
666 | { | |
667 | /* | |
668 | * Convert jiffies to nanoseconds and separate with | |
669 | * one divide. | |
670 | */ | |
f8bd2258 | 671 | u32 rem; |
8b9365d7 | 672 | |
f8bd2258 RZ |
673 | value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, |
674 | NSEC_PER_SEC, &rem); | |
675 | value->tv_usec = rem / NSEC_PER_USEC; | |
8b9365d7 | 676 | } |
456a09dc | 677 | EXPORT_SYMBOL(jiffies_to_timeval); |
8b9365d7 IM |
678 | |
679 | /* | |
680 | * Convert jiffies/jiffies_64 to clock_t and back. | |
681 | */ | |
cbbc719f | 682 | clock_t jiffies_to_clock_t(unsigned long x) |
8b9365d7 IM |
683 | { |
684 | #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 | |
6ffc787a DF |
685 | # if HZ < USER_HZ |
686 | return x * (USER_HZ / HZ); | |
687 | # else | |
8b9365d7 | 688 | return x / (HZ / USER_HZ); |
6ffc787a | 689 | # endif |
8b9365d7 | 690 | #else |
71abb3af | 691 | return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ); |
8b9365d7 IM |
692 | #endif |
693 | } | |
694 | EXPORT_SYMBOL(jiffies_to_clock_t); | |
695 | ||
696 | unsigned long clock_t_to_jiffies(unsigned long x) | |
697 | { | |
698 | #if (HZ % USER_HZ)==0 | |
699 | if (x >= ~0UL / (HZ / USER_HZ)) | |
700 | return ~0UL; | |
701 | return x * (HZ / USER_HZ); | |
702 | #else | |
8b9365d7 IM |
703 | /* Don't worry about loss of precision here .. */ |
704 | if (x >= ~0UL / HZ * USER_HZ) | |
705 | return ~0UL; | |
706 | ||
707 | /* .. but do try to contain it here */ | |
71abb3af | 708 | return div_u64((u64)x * HZ, USER_HZ); |
8b9365d7 IM |
709 | #endif |
710 | } | |
711 | EXPORT_SYMBOL(clock_t_to_jiffies); | |
712 | ||
713 | u64 jiffies_64_to_clock_t(u64 x) | |
714 | { | |
715 | #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 | |
6ffc787a | 716 | # if HZ < USER_HZ |
71abb3af | 717 | x = div_u64(x * USER_HZ, HZ); |
ec03d707 | 718 | # elif HZ > USER_HZ |
71abb3af | 719 | x = div_u64(x, HZ / USER_HZ); |
ec03d707 AM |
720 | # else |
721 | /* Nothing to do */ | |
6ffc787a | 722 | # endif |
8b9365d7 IM |
723 | #else |
724 | /* | |
725 | * There are better ways that don't overflow early, | |
726 | * but even this doesn't overflow in hundreds of years | |
727 | * in 64 bits, so.. | |
728 | */ | |
71abb3af | 729 | x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ)); |
8b9365d7 IM |
730 | #endif |
731 | return x; | |
732 | } | |
8b9365d7 IM |
733 | EXPORT_SYMBOL(jiffies_64_to_clock_t); |
734 | ||
735 | u64 nsec_to_clock_t(u64 x) | |
736 | { | |
737 | #if (NSEC_PER_SEC % USER_HZ) == 0 | |
71abb3af | 738 | return div_u64(x, NSEC_PER_SEC / USER_HZ); |
8b9365d7 | 739 | #elif (USER_HZ % 512) == 0 |
71abb3af | 740 | return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512); |
8b9365d7 IM |
741 | #else |
742 | /* | |
743 | * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024, | |
744 | * overflow after 64.99 years. | |
745 | * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ... | |
746 | */ | |
71abb3af | 747 | return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ); |
8b9365d7 | 748 | #endif |
8b9365d7 IM |
749 | } |
750 | ||
07e5f5e3 FW |
751 | u64 jiffies64_to_nsecs(u64 j) |
752 | { | |
753 | #if !(NSEC_PER_SEC % HZ) | |
754 | return (NSEC_PER_SEC / HZ) * j; | |
755 | # else | |
756 | return div_u64(j * HZ_TO_NSEC_NUM, HZ_TO_NSEC_DEN); | |
757 | #endif | |
758 | } | |
759 | EXPORT_SYMBOL(jiffies64_to_nsecs); | |
760 | ||
b7b20df9 | 761 | /** |
a1dabb6b | 762 | * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 |
b7b20df9 HS |
763 | * |
764 | * @n: nsecs in u64 | |
765 | * | |
766 | * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. | |
767 | * And this doesn't return MAX_JIFFY_OFFSET since this function is designed | |
768 | * for scheduler, not for use in device drivers to calculate timeout value. | |
769 | * | |
770 | * note: | |
771 | * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) | |
772 | * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years | |
773 | */ | |
a1dabb6b | 774 | u64 nsecs_to_jiffies64(u64 n) |
b7b20df9 HS |
775 | { |
776 | #if (NSEC_PER_SEC % HZ) == 0 | |
777 | /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ | |
778 | return div_u64(n, NSEC_PER_SEC / HZ); | |
779 | #elif (HZ % 512) == 0 | |
780 | /* overflow after 292 years if HZ = 1024 */ | |
781 | return div_u64(n * HZ / 512, NSEC_PER_SEC / 512); | |
782 | #else | |
783 | /* | |
784 | * Generic case - optimized for cases where HZ is a multiple of 3. | |
785 | * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc. | |
786 | */ | |
787 | return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); | |
788 | #endif | |
789 | } | |
7bd0e226 | 790 | EXPORT_SYMBOL(nsecs_to_jiffies64); |
b7b20df9 | 791 | |
a1dabb6b VP |
792 | /** |
793 | * nsecs_to_jiffies - Convert nsecs in u64 to jiffies | |
794 | * | |
795 | * @n: nsecs in u64 | |
796 | * | |
797 | * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. | |
798 | * And this doesn't return MAX_JIFFY_OFFSET since this function is designed | |
799 | * for scheduler, not for use in device drivers to calculate timeout value. | |
800 | * | |
801 | * note: | |
802 | * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) | |
803 | * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years | |
804 | */ | |
805 | unsigned long nsecs_to_jiffies(u64 n) | |
806 | { | |
807 | return (unsigned long)nsecs_to_jiffies64(n); | |
808 | } | |
d560fed6 | 809 | EXPORT_SYMBOL_GPL(nsecs_to_jiffies); |
a1dabb6b | 810 | |
bc2c53e5 DD |
811 | /* |
812 | * Add two timespec64 values and do a safety check for overflow. | |
813 | * It's assumed that both values are valid (>= 0). | |
814 | * And, each timespec64 is in normalized form. | |
815 | */ | |
816 | struct timespec64 timespec64_add_safe(const struct timespec64 lhs, | |
817 | const struct timespec64 rhs) | |
818 | { | |
819 | struct timespec64 res; | |
820 | ||
469e857f | 821 | set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec, |
bc2c53e5 DD |
822 | lhs.tv_nsec + rhs.tv_nsec); |
823 | ||
824 | if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) { | |
825 | res.tv_sec = TIME64_MAX; | |
826 | res.tv_nsec = 0; | |
827 | } | |
828 | ||
829 | return res; | |
830 | } | |
f59dd9c8 DD |
831 | |
832 | int get_timespec64(struct timespec64 *ts, | |
ea2ce8f3 | 833 | const struct __kernel_timespec __user *uts) |
f59dd9c8 | 834 | { |
ea2ce8f3 | 835 | struct __kernel_timespec kts; |
f59dd9c8 DD |
836 | int ret; |
837 | ||
838 | ret = copy_from_user(&kts, uts, sizeof(kts)); | |
839 | if (ret) | |
840 | return -EFAULT; | |
841 | ||
842 | ts->tv_sec = kts.tv_sec; | |
ea2ce8f3 DD |
843 | |
844 | /* Zero out the padding for 32 bit systems or in compat mode */ | |
845 | if (IS_ENABLED(CONFIG_64BIT_TIME) && (!IS_ENABLED(CONFIG_64BIT) || in_compat_syscall())) | |
846 | kts.tv_nsec &= 0xFFFFFFFFUL; | |
847 | ||
f59dd9c8 DD |
848 | ts->tv_nsec = kts.tv_nsec; |
849 | ||
850 | return 0; | |
851 | } | |
852 | EXPORT_SYMBOL_GPL(get_timespec64); | |
853 | ||
854 | int put_timespec64(const struct timespec64 *ts, | |
ea2ce8f3 | 855 | struct __kernel_timespec __user *uts) |
f59dd9c8 | 856 | { |
ea2ce8f3 | 857 | struct __kernel_timespec kts = { |
f59dd9c8 DD |
858 | .tv_sec = ts->tv_sec, |
859 | .tv_nsec = ts->tv_nsec | |
860 | }; | |
ea2ce8f3 | 861 | |
f59dd9c8 DD |
862 | return copy_to_user(uts, &kts, sizeof(kts)) ? -EFAULT : 0; |
863 | } | |
864 | EXPORT_SYMBOL_GPL(put_timespec64); | |
d5b7ffbf | 865 | |
9afc5eee AB |
866 | int __get_old_timespec32(struct timespec64 *ts64, |
867 | const struct old_timespec32 __user *cts) | |
1c68adf6 | 868 | { |
9afc5eee | 869 | struct old_timespec32 ts; |
1c68adf6 DD |
870 | int ret; |
871 | ||
872 | ret = copy_from_user(&ts, cts, sizeof(ts)); | |
873 | if (ret) | |
874 | return -EFAULT; | |
875 | ||
876 | ts64->tv_sec = ts.tv_sec; | |
877 | ts64->tv_nsec = ts.tv_nsec; | |
878 | ||
879 | return 0; | |
880 | } | |
881 | ||
9afc5eee AB |
882 | int __put_old_timespec32(const struct timespec64 *ts64, |
883 | struct old_timespec32 __user *cts) | |
1c68adf6 | 884 | { |
9afc5eee | 885 | struct old_timespec32 ts = { |
1c68adf6 DD |
886 | .tv_sec = ts64->tv_sec, |
887 | .tv_nsec = ts64->tv_nsec | |
888 | }; | |
889 | return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0; | |
890 | } | |
891 | ||
9afc5eee | 892 | int get_old_timespec32(struct timespec64 *ts, const void __user *uts) |
1c68adf6 DD |
893 | { |
894 | if (COMPAT_USE_64BIT_TIME) | |
895 | return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; | |
896 | else | |
9afc5eee | 897 | return __get_old_timespec32(ts, uts); |
1c68adf6 | 898 | } |
9afc5eee | 899 | EXPORT_SYMBOL_GPL(get_old_timespec32); |
1c68adf6 | 900 | |
9afc5eee | 901 | int put_old_timespec32(const struct timespec64 *ts, void __user *uts) |
1c68adf6 DD |
902 | { |
903 | if (COMPAT_USE_64BIT_TIME) | |
904 | return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; | |
905 | else | |
9afc5eee | 906 | return __put_old_timespec32(ts, uts); |
1c68adf6 | 907 | } |
9afc5eee | 908 | EXPORT_SYMBOL_GPL(put_old_timespec32); |
1c68adf6 | 909 | |
d5b7ffbf | 910 | int get_itimerspec64(struct itimerspec64 *it, |
d0dd63a8 | 911 | const struct __kernel_itimerspec __user *uit) |
d5b7ffbf DD |
912 | { |
913 | int ret; | |
914 | ||
915 | ret = get_timespec64(&it->it_interval, &uit->it_interval); | |
916 | if (ret) | |
917 | return ret; | |
918 | ||
919 | ret = get_timespec64(&it->it_value, &uit->it_value); | |
920 | ||
921 | return ret; | |
922 | } | |
923 | EXPORT_SYMBOL_GPL(get_itimerspec64); | |
924 | ||
925 | int put_itimerspec64(const struct itimerspec64 *it, | |
d0dd63a8 | 926 | struct __kernel_itimerspec __user *uit) |
d5b7ffbf DD |
927 | { |
928 | int ret; | |
929 | ||
930 | ret = put_timespec64(&it->it_interval, &uit->it_interval); | |
931 | if (ret) | |
932 | return ret; | |
933 | ||
934 | ret = put_timespec64(&it->it_value, &uit->it_value); | |
935 | ||
936 | return ret; | |
937 | } | |
938 | EXPORT_SYMBOL_GPL(put_itimerspec64); | |
afef05cf | 939 | |
9afc5eee AB |
940 | int get_old_itimerspec32(struct itimerspec64 *its, |
941 | const struct old_itimerspec32 __user *uits) | |
afef05cf DD |
942 | { |
943 | ||
9afc5eee AB |
944 | if (__get_old_timespec32(&its->it_interval, &uits->it_interval) || |
945 | __get_old_timespec32(&its->it_value, &uits->it_value)) | |
afef05cf DD |
946 | return -EFAULT; |
947 | return 0; | |
948 | } | |
9afc5eee | 949 | EXPORT_SYMBOL_GPL(get_old_itimerspec32); |
afef05cf | 950 | |
9afc5eee AB |
951 | int put_old_itimerspec32(const struct itimerspec64 *its, |
952 | struct old_itimerspec32 __user *uits) | |
afef05cf | 953 | { |
9afc5eee AB |
954 | if (__put_old_timespec32(&its->it_interval, &uits->it_interval) || |
955 | __put_old_timespec32(&its->it_value, &uits->it_value)) | |
afef05cf DD |
956 | return -EFAULT; |
957 | return 0; | |
958 | } | |
9afc5eee | 959 | EXPORT_SYMBOL_GPL(put_old_itimerspec32); |