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 #if defined(CONFIG_64BIT) || defined(CONFIG_COMPAT_32BIT_TIME) 47 #define __WANT_OLD_TIME_TYPE_SYSCALL 1 48 #endif 49 50 static_assert(sizeof(__kernel_old_time_t) == 8 ? IS_ENABLED(__WANT_OLD_TIME_TYPE_SYSCALL) : true); 51 52 /* 53 * The timezone where the local system is located. Used as a default by some 54 * programs who obtain this value by using gettimeofday. 55 */ 56 struct timezone sys_tz; 57 58 EXPORT_SYMBOL(sys_tz); 59 60 #if defined(__ARCH_WANT_SYS_TIME) && defined(__WANT_OLD_TIME_TYPE_SYSCALL) 61 62 /* 63 * sys_time() can be implemented in user-level using 64 * sys_gettimeofday(). Is this for backwards compatibility? If so, 65 * why not move it into the appropriate arch directory (for those 66 * architectures that need it). 67 */ 68 SYSCALL_DEFINE1(time, __kernel_old_time_t __user *, tloc) 69 { 70 __kernel_old_time_t i = (__kernel_old_time_t)ktime_get_real_seconds(); 71 72 if (tloc) { 73 if (put_user(i,tloc)) 74 return -EFAULT; 75 } 76 force_successful_syscall_return(); 77 return i; 78 } 79 80 /* 81 * sys_stime() can be implemented in user-level using 82 * sys_settimeofday(). Is this for backwards compatibility? If so, 83 * why not move it into the appropriate arch directory (for those 84 * architectures that need it). 85 */ 86 87 SYSCALL_DEFINE1(stime, __kernel_old_time_t __user *, tptr) 88 { 89 struct timespec64 tv; 90 int err; 91 92 if (get_user(tv.tv_sec, tptr)) 93 return -EFAULT; 94 95 tv.tv_nsec = 0; 96 97 err = security_settime64(&tv, NULL); 98 if (err) 99 return err; 100 101 do_settimeofday64(&tv); 102 return 0; 103 } 104 105 #endif /* __ARCH_WANT_SYS_TIME && __WANT_OLD_TIME_TYPE_SYSCALL */ 106 107 #ifdef CONFIG_COMPAT_32BIT_TIME 108 #ifdef __ARCH_WANT_SYS_TIME32 109 110 /* old_time32_t is a 32 bit "long" and needs to get converted. */ 111 SYSCALL_DEFINE1(time32, old_time32_t __user *, tloc) 112 { 113 old_time32_t i; 114 115 i = (old_time32_t)ktime_get_real_seconds(); 116 117 if (tloc) { 118 if (put_user(i,tloc)) 119 return -EFAULT; 120 } 121 force_successful_syscall_return(); 122 return i; 123 } 124 125 SYSCALL_DEFINE1(stime32, old_time32_t __user *, tptr) 126 { 127 struct timespec64 tv; 128 int err; 129 130 if (get_user(tv.tv_sec, tptr)) 131 return -EFAULT; 132 133 tv.tv_nsec = 0; 134 135 err = security_settime64(&tv, NULL); 136 if (err) 137 return err; 138 139 do_settimeofday64(&tv); 140 return 0; 141 } 142 143 #endif /* __ARCH_WANT_SYS_TIME32 */ 144 #endif 145 146 #ifdef __WANT_OLD_TIME_TYPE_SYSCALL 147 SYSCALL_DEFINE2(gettimeofday, struct __kernel_old_timeval __user *, tv, 148 struct timezone __user *, tz) 149 { 150 if (likely(tv != NULL)) { 151 struct timespec64 ts; 152 153 ktime_get_real_ts64(&ts); 154 if (put_user(ts.tv_sec, &tv->tv_sec) || 155 put_user(ts.tv_nsec / 1000, &tv->tv_usec)) 156 return -EFAULT; 157 } 158 if (unlikely(tz != NULL)) { 159 if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) 160 return -EFAULT; 161 } 162 return 0; 163 } 164 #endif /* __WANT_OLD_TIME_TYPE_SYSCALL */ 165 166 /* 167 * In case for some reason the CMOS clock has not already been running 168 * in UTC, but in some local time: The first time we set the timezone, 169 * we will warp the clock so that it is ticking UTC time instead of 170 * local time. Presumably, if someone is setting the timezone then we 171 * are running in an environment where the programs understand about 172 * timezones. This should be done at boot time in the /etc/rc script, 173 * as soon as possible, so that the clock can be set right. Otherwise, 174 * various programs will get confused when the clock gets warped. 175 */ 176 177 int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz) 178 { 179 static int firsttime = 1; 180 int error = 0; 181 182 if (tv && !timespec64_valid_settod(tv)) 183 return -EINVAL; 184 185 error = security_settime64(tv, tz); 186 if (error) 187 return error; 188 189 if (tz) { 190 /* Verify we're within the +-15 hrs range */ 191 if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60) 192 return -EINVAL; 193 194 sys_tz = *tz; 195 update_vsyscall_tz(); 196 if (firsttime) { 197 firsttime = 0; 198 if (!tv) 199 timekeeping_warp_clock(); 200 } 201 } 202 if (tv) 203 return do_settimeofday64(tv); 204 return 0; 205 } 206 207 SYSCALL_DEFINE2(settimeofday, struct __kernel_old_timeval __user *, tv, 208 struct timezone __user *, tz) 209 { 210 struct timespec64 new_ts; 211 struct timezone new_tz; 212 213 if (tv) { 214 if (!IS_ENABLED(__WANT_OLD_TIME_TYPE_SYSCALL)) 215 return -EINVAL; 216 217 if (get_user(new_ts.tv_sec, &tv->tv_sec) || 218 get_user(new_ts.tv_nsec, &tv->tv_usec)) 219 return -EFAULT; 220 221 if (new_ts.tv_nsec >= USEC_PER_SEC || new_ts.tv_nsec < 0) 222 return -EINVAL; 223 224 new_ts.tv_nsec *= NSEC_PER_USEC; 225 } 226 if (tz) { 227 if (copy_from_user(&new_tz, tz, sizeof(*tz))) 228 return -EFAULT; 229 } 230 231 return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); 232 } 233 234 #ifdef CONFIG_COMPAT_32BIT_TIME 235 COMPAT_SYSCALL_DEFINE2(gettimeofday, struct old_timeval32 __user *, tv, 236 struct timezone __user *, tz) 237 { 238 if (tv) { 239 struct timespec64 ts; 240 241 ktime_get_real_ts64(&ts); 242 if (put_user(ts.tv_sec, &tv->tv_sec) || 243 put_user(ts.tv_nsec / 1000, &tv->tv_usec)) 244 return -EFAULT; 245 } 246 if (tz) { 247 if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) 248 return -EFAULT; 249 } 250 251 return 0; 252 } 253 #endif /* CONFIG_COMPAT_32BIT_TIME */ 254 255 #ifdef CONFIG_COMPAT 256 COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv, 257 struct timezone __user *, tz) 258 { 259 struct timespec64 new_ts; 260 struct timezone new_tz; 261 262 if (tv) { 263 if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME)) 264 return -EINVAL; 265 266 if (get_user(new_ts.tv_sec, &tv->tv_sec) || 267 get_user(new_ts.tv_nsec, &tv->tv_usec)) 268 return -EFAULT; 269 270 if (new_ts.tv_nsec >= USEC_PER_SEC || new_ts.tv_nsec < 0) 271 return -EINVAL; 272 273 new_ts.tv_nsec *= NSEC_PER_USEC; 274 } 275 if (tz) { 276 if (copy_from_user(&new_tz, tz, sizeof(*tz))) 277 return -EFAULT; 278 } 279 280 return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); 281 } 282 #endif /* CONFIG_COMPAT */ 283 284 #ifdef CONFIG_64BIT 285 SYSCALL_DEFINE1(adjtimex, struct __kernel_timex __user *, txc_p) 286 { 287 struct __kernel_timex txc; /* Local copy of parameter */ 288 int ret; 289 290 /* Copy the user data space into the kernel copy 291 * structure. But bear in mind that the structures 292 * may change 293 */ 294 if (copy_from_user(&txc, txc_p, sizeof(struct __kernel_timex))) 295 return -EFAULT; 296 ret = do_adjtimex(&txc); 297 return copy_to_user(txc_p, &txc, sizeof(struct __kernel_timex)) ? -EFAULT : ret; 298 } 299 #endif 300 301 #ifdef CONFIG_COMPAT_32BIT_TIME 302 int get_old_timex32(struct __kernel_timex *txc, const struct old_timex32 __user *utp) 303 { 304 struct old_timex32 tx32; 305 306 memset(txc, 0, sizeof(struct __kernel_timex)); 307 if (copy_from_user(&tx32, utp, sizeof(struct old_timex32))) 308 return -EFAULT; 309 310 txc->modes = tx32.modes; 311 txc->offset = tx32.offset; 312 txc->freq = tx32.freq; 313 txc->maxerror = tx32.maxerror; 314 txc->esterror = tx32.esterror; 315 txc->status = tx32.status; 316 txc->constant = tx32.constant; 317 txc->precision = tx32.precision; 318 txc->tolerance = tx32.tolerance; 319 txc->time.tv_sec = tx32.time.tv_sec; 320 txc->time.tv_usec = tx32.time.tv_usec; 321 txc->tick = tx32.tick; 322 txc->ppsfreq = tx32.ppsfreq; 323 txc->jitter = tx32.jitter; 324 txc->shift = tx32.shift; 325 txc->stabil = tx32.stabil; 326 txc->jitcnt = tx32.jitcnt; 327 txc->calcnt = tx32.calcnt; 328 txc->errcnt = tx32.errcnt; 329 txc->stbcnt = tx32.stbcnt; 330 331 return 0; 332 } 333 334 int put_old_timex32(struct old_timex32 __user *utp, const struct __kernel_timex *txc) 335 { 336 struct old_timex32 tx32; 337 338 memset(&tx32, 0, sizeof(struct old_timex32)); 339 tx32.modes = txc->modes; 340 tx32.offset = txc->offset; 341 tx32.freq = txc->freq; 342 tx32.maxerror = txc->maxerror; 343 tx32.esterror = txc->esterror; 344 tx32.status = txc->status; 345 tx32.constant = txc->constant; 346 tx32.precision = txc->precision; 347 tx32.tolerance = txc->tolerance; 348 tx32.time.tv_sec = txc->time.tv_sec; 349 tx32.time.tv_usec = txc->time.tv_usec; 350 tx32.tick = txc->tick; 351 tx32.ppsfreq = txc->ppsfreq; 352 tx32.jitter = txc->jitter; 353 tx32.shift = txc->shift; 354 tx32.stabil = txc->stabil; 355 tx32.jitcnt = txc->jitcnt; 356 tx32.calcnt = txc->calcnt; 357 tx32.errcnt = txc->errcnt; 358 tx32.stbcnt = txc->stbcnt; 359 tx32.tai = txc->tai; 360 if (copy_to_user(utp, &tx32, sizeof(struct old_timex32))) 361 return -EFAULT; 362 return 0; 363 } 364 365 SYSCALL_DEFINE1(adjtimex_time32, struct old_timex32 __user *, utp) 366 { 367 struct __kernel_timex txc; 368 int err, ret; 369 370 err = get_old_timex32(&txc, utp); 371 if (err) 372 return err; 373 374 ret = do_adjtimex(&txc); 375 376 err = put_old_timex32(utp, &txc); 377 if (err) 378 return err; 379 380 return ret; 381 } 382 #endif 383 384 #if HZ > MSEC_PER_SEC || (MSEC_PER_SEC % HZ) 385 /** 386 * jiffies_to_msecs - Convert jiffies to milliseconds 387 * @j: jiffies value 388 * 389 * Return: milliseconds value 390 */ 391 unsigned int jiffies_to_msecs(const unsigned long j) 392 { 393 #if HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) 394 return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); 395 #else 396 # if BITS_PER_LONG == 32 397 return (HZ_TO_MSEC_MUL32 * j + (1ULL << HZ_TO_MSEC_SHR32) - 1) >> 398 HZ_TO_MSEC_SHR32; 399 # else 400 return DIV_ROUND_UP(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); 401 # endif 402 #endif 403 } 404 EXPORT_SYMBOL(jiffies_to_msecs); 405 #endif 406 407 #if (USEC_PER_SEC % HZ) 408 /** 409 * jiffies_to_usecs - Convert jiffies to microseconds 410 * @j: jiffies value 411 * 412 * Return: microseconds value 413 */ 414 unsigned int jiffies_to_usecs(const unsigned long j) 415 { 416 /* 417 * Hz usually doesn't go much further MSEC_PER_SEC. 418 * jiffies_to_usecs() and usecs_to_jiffies() depend on that. 419 */ 420 BUILD_BUG_ON(HZ > USEC_PER_SEC); 421 422 #if BITS_PER_LONG == 32 423 return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; 424 #else 425 return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; 426 #endif 427 } 428 EXPORT_SYMBOL(jiffies_to_usecs); 429 #endif 430 431 /** 432 * mktime64 - Converts date to seconds. 433 * @year0: year to convert 434 * @mon0: month to convert 435 * @day: day to convert 436 * @hour: hour to convert 437 * @min: minute to convert 438 * @sec: second to convert 439 * 440 * Converts Gregorian date to seconds since 1970-01-01 00:00:00. 441 * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 442 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. 443 * 444 * [For the Julian calendar (which was used in Russia before 1917, 445 * Britain & colonies before 1752, anywhere else before 1582, 446 * and is still in use by some communities) leave out the 447 * -year/100+year/400 terms, and add 10.] 448 * 449 * This algorithm was first published by Gauss (I think). 450 * 451 * A leap second can be indicated by calling this function with sec as 452 * 60 (allowable under ISO 8601). The leap second is treated the same 453 * as the following second since they don't exist in UNIX time. 454 * 455 * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight 456 * tomorrow - (allowable under ISO 8601) is supported. 457 * 458 * Return: seconds since the epoch time for the given input date 459 */ 460 time64_t mktime64(const unsigned int year0, const unsigned int mon0, 461 const unsigned int day, const unsigned int hour, 462 const unsigned int min, const unsigned int sec) 463 { 464 unsigned int mon = mon0, year = year0; 465 466 /* 1..12 -> 11,12,1..10 */ 467 if (0 >= (int) (mon -= 2)) { 468 mon += 12; /* Puts Feb last since it has leap day */ 469 year -= 1; 470 } 471 472 return ((((time64_t) 473 (year/4 - year/100 + year/400 + 367*mon/12 + day) + 474 year*365 - 719499 475 )*24 + hour /* now have hours - midnight tomorrow handled here */ 476 )*60 + min /* now have minutes */ 477 )*60 + sec; /* finally seconds */ 478 } 479 EXPORT_SYMBOL(mktime64); 480 481 struct __kernel_old_timeval ns_to_kernel_old_timeval(s64 nsec) 482 { 483 struct timespec64 ts = ns_to_timespec64(nsec); 484 struct __kernel_old_timeval tv; 485 486 tv.tv_sec = ts.tv_sec; 487 tv.tv_usec = (suseconds_t)ts.tv_nsec / 1000; 488 489 return tv; 490 } 491 EXPORT_SYMBOL(ns_to_kernel_old_timeval); 492 493 /** 494 * set_normalized_timespec64 - set timespec sec and nsec parts and normalize 495 * 496 * @ts: pointer to timespec variable to be set 497 * @sec: seconds to set 498 * @nsec: nanoseconds to set 499 * 500 * Set seconds and nanoseconds field of a timespec variable and 501 * normalize to the timespec storage format 502 * 503 * Note: The tv_nsec part is always in the range of 0 <= tv_nsec < NSEC_PER_SEC. 504 * For negative values only the tv_sec field is negative ! 505 */ 506 void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec) 507 { 508 while (nsec >= NSEC_PER_SEC) { 509 /* 510 * The following asm() prevents the compiler from 511 * optimising this loop into a modulo operation. See 512 * also __iter_div_u64_rem() in include/linux/time.h 513 */ 514 asm("" : "+rm"(nsec)); 515 nsec -= NSEC_PER_SEC; 516 ++sec; 517 } 518 while (nsec < 0) { 519 asm("" : "+rm"(nsec)); 520 nsec += NSEC_PER_SEC; 521 --sec; 522 } 523 ts->tv_sec = sec; 524 ts->tv_nsec = nsec; 525 } 526 EXPORT_SYMBOL(set_normalized_timespec64); 527 528 /** 529 * ns_to_timespec64 - Convert nanoseconds to timespec64 530 * @nsec: the nanoseconds value to be converted 531 * 532 * Return: the timespec64 representation of the nsec parameter. 533 */ 534 struct timespec64 ns_to_timespec64(s64 nsec) 535 { 536 struct timespec64 ts = { 0, 0 }; 537 s32 rem; 538 539 if (likely(nsec > 0)) { 540 ts.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem); 541 ts.tv_nsec = rem; 542 } else if (nsec < 0) { 543 /* 544 * With negative times, tv_sec points to the earlier 545 * second, and tv_nsec counts the nanoseconds since 546 * then, so tv_nsec is always a positive number. 547 */ 548 ts.tv_sec = -div_u64_rem(-nsec - 1, NSEC_PER_SEC, &rem) - 1; 549 ts.tv_nsec = NSEC_PER_SEC - rem - 1; 550 } 551 552 return ts; 553 } 554 EXPORT_SYMBOL(ns_to_timespec64); 555 556 /** 557 * __msecs_to_jiffies: - convert milliseconds to jiffies 558 * @m: time in milliseconds 559 * 560 * conversion is done as follows: 561 * 562 * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) 563 * 564 * - 'too large' values [that would result in larger than 565 * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. 566 * 567 * - all other values are converted to jiffies by either multiplying 568 * the input value by a factor or dividing it with a factor and 569 * handling any 32-bit overflows. 570 * for the details see _msecs_to_jiffies() 571 * 572 * msecs_to_jiffies() checks for the passed in value being a constant 573 * via __builtin_constant_p() allowing gcc to eliminate most of the 574 * code, __msecs_to_jiffies() is called if the value passed does not 575 * allow constant folding and the actual conversion must be done at 576 * runtime. 577 * The _msecs_to_jiffies helpers are the HZ dependent conversion 578 * routines found in include/linux/jiffies.h 579 * 580 * Return: jiffies value 581 */ 582 unsigned long __msecs_to_jiffies(const unsigned int m) 583 { 584 /* 585 * Negative value, means infinite timeout: 586 */ 587 if ((int)m < 0) 588 return MAX_JIFFY_OFFSET; 589 return _msecs_to_jiffies(m); 590 } 591 EXPORT_SYMBOL(__msecs_to_jiffies); 592 593 /** 594 * __usecs_to_jiffies: - convert microseconds to jiffies 595 * @u: time in milliseconds 596 * 597 * Return: jiffies value 598 */ 599 unsigned long __usecs_to_jiffies(const unsigned int u) 600 { 601 if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) 602 return MAX_JIFFY_OFFSET; 603 return _usecs_to_jiffies(u); 604 } 605 EXPORT_SYMBOL(__usecs_to_jiffies); 606 607 /** 608 * timespec64_to_jiffies - convert a timespec64 value to jiffies 609 * @value: pointer to &struct timespec64 610 * 611 * The TICK_NSEC - 1 rounds up the value to the next resolution. Note 612 * that a remainder subtract here would not do the right thing as the 613 * resolution values don't fall on second boundaries. I.e. the line: 614 * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding. 615 * Note that due to the small error in the multiplier here, this 616 * rounding is incorrect for sufficiently large values of tv_nsec, but 617 * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're 618 * OK. 619 * 620 * Rather, we just shift the bits off the right. 621 * 622 * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec 623 * value to a scaled second value. 624 * 625 * Return: jiffies value 626 */ 627 unsigned long 628 timespec64_to_jiffies(const struct timespec64 *value) 629 { 630 u64 sec = value->tv_sec; 631 long nsec = value->tv_nsec + TICK_NSEC - 1; 632 633 if (sec >= MAX_SEC_IN_JIFFIES){ 634 sec = MAX_SEC_IN_JIFFIES; 635 nsec = 0; 636 } 637 return ((sec * SEC_CONVERSION) + 638 (((u64)nsec * NSEC_CONVERSION) >> 639 (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; 640 641 } 642 EXPORT_SYMBOL(timespec64_to_jiffies); 643 644 /** 645 * jiffies_to_timespec64 - convert jiffies value to &struct timespec64 646 * @jiffies: jiffies value 647 * @value: pointer to &struct timespec64 648 */ 649 void 650 jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value) 651 { 652 /* 653 * Convert jiffies to nanoseconds and separate with 654 * one divide. 655 */ 656 u32 rem; 657 value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, 658 NSEC_PER_SEC, &rem); 659 value->tv_nsec = rem; 660 } 661 EXPORT_SYMBOL(jiffies_to_timespec64); 662 663 /* 664 * Convert jiffies/jiffies_64 to clock_t and back. 665 */ 666 667 /** 668 * jiffies_to_clock_t - Convert jiffies to clock_t 669 * @x: jiffies value 670 * 671 * Return: jiffies converted to clock_t (CLOCKS_PER_SEC) 672 */ 673 clock_t jiffies_to_clock_t(unsigned long x) 674 { 675 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 676 # if HZ < USER_HZ 677 return x * (USER_HZ / HZ); 678 # else 679 return x / (HZ / USER_HZ); 680 # endif 681 #else 682 return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ); 683 #endif 684 } 685 EXPORT_SYMBOL(jiffies_to_clock_t); 686 687 /** 688 * clock_t_to_jiffies - Convert clock_t to jiffies 689 * @x: clock_t value 690 * 691 * Return: clock_t value converted to jiffies 692 */ 693 unsigned long clock_t_to_jiffies(unsigned long x) 694 { 695 #if (HZ % USER_HZ)==0 696 if (x >= ~0UL / (HZ / USER_HZ)) 697 return ~0UL; 698 return x * (HZ / USER_HZ); 699 #else 700 /* Don't worry about loss of precision here .. */ 701 if (x >= ~0UL / HZ * USER_HZ) 702 return ~0UL; 703 704 /* .. but do try to contain it here */ 705 return div_u64((u64)x * HZ, USER_HZ); 706 #endif 707 } 708 EXPORT_SYMBOL(clock_t_to_jiffies); 709 710 /** 711 * jiffies_64_to_clock_t - Convert jiffies_64 to clock_t 712 * @x: jiffies_64 value 713 * 714 * Return: jiffies_64 value converted to 64-bit "clock_t" (CLOCKS_PER_SEC) 715 */ 716 notrace u64 jiffies_64_to_clock_t(u64 x) 717 { 718 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 719 # if HZ < USER_HZ 720 x = div_u64(x * USER_HZ, HZ); 721 # elif HZ > USER_HZ 722 x = div_u64(x, HZ / USER_HZ); 723 # else 724 /* Nothing to do */ 725 # endif 726 #else 727 /* 728 * There are better ways that don't overflow early, 729 * but even this doesn't overflow in hundreds of years 730 * in 64 bits, so.. 731 */ 732 x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ)); 733 #endif 734 return x; 735 } 736 EXPORT_SYMBOL(jiffies_64_to_clock_t); 737 738 /** 739 * nsec_to_clock_t - Convert nsec value to clock_t 740 * @x: nsec value 741 * 742 * Return: nsec value converted to 64-bit "clock_t" (CLOCKS_PER_SEC) 743 */ 744 u64 nsec_to_clock_t(u64 x) 745 { 746 #if (NSEC_PER_SEC % USER_HZ) == 0 747 return div_u64(x, NSEC_PER_SEC / USER_HZ); 748 #elif (USER_HZ % 512) == 0 749 return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512); 750 #else 751 /* 752 * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024, 753 * overflow after 64.99 years. 754 * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ... 755 */ 756 return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ); 757 #endif 758 } 759 760 /** 761 * jiffies64_to_nsecs - Convert jiffies64 to nanoseconds 762 * @j: jiffies64 value 763 * 764 * Return: nanoseconds value 765 */ 766 u64 jiffies64_to_nsecs(u64 j) 767 { 768 #if !(NSEC_PER_SEC % HZ) 769 return (NSEC_PER_SEC / HZ) * j; 770 # else 771 return div_u64(j * HZ_TO_NSEC_NUM, HZ_TO_NSEC_DEN); 772 #endif 773 } 774 EXPORT_SYMBOL(jiffies64_to_nsecs); 775 776 /** 777 * jiffies64_to_msecs - Convert jiffies64 to milliseconds 778 * @j: jiffies64 value 779 * 780 * Return: milliseconds value 781 */ 782 u64 jiffies64_to_msecs(const u64 j) 783 { 784 #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) 785 return (MSEC_PER_SEC / HZ) * j; 786 #else 787 return div_u64(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); 788 #endif 789 } 790 EXPORT_SYMBOL(jiffies64_to_msecs); 791 792 /** 793 * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 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 * Return: nsecs converted to jiffies64 value 806 */ 807 u64 nsecs_to_jiffies64(u64 n) 808 { 809 #if (NSEC_PER_SEC % HZ) == 0 810 /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ 811 return div_u64(n, NSEC_PER_SEC / HZ); 812 #elif (HZ % 512) == 0 813 /* overflow after 292 years if HZ = 1024 */ 814 return div_u64(n * HZ / 512, NSEC_PER_SEC / 512); 815 #else 816 /* 817 * Generic case - optimized for cases where HZ is a multiple of 3. 818 * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc. 819 */ 820 return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); 821 #endif 822 } 823 EXPORT_SYMBOL(nsecs_to_jiffies64); 824 825 /** 826 * nsecs_to_jiffies - Convert nsecs in u64 to jiffies 827 * 828 * @n: nsecs in u64 829 * 830 * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. 831 * And this doesn't return MAX_JIFFY_OFFSET since this function is designed 832 * for scheduler, not for use in device drivers to calculate timeout value. 833 * 834 * note: 835 * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) 836 * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years 837 * 838 * Return: nsecs converted to jiffies value 839 */ 840 unsigned long nsecs_to_jiffies(u64 n) 841 { 842 return (unsigned long)nsecs_to_jiffies64(n); 843 } 844 EXPORT_SYMBOL_GPL(nsecs_to_jiffies); 845 846 /** 847 * timespec64_add_safe - Add two timespec64 values and do a safety check 848 * for overflow. 849 * @lhs: first (left) timespec64 to add 850 * @rhs: second (right) timespec64 to add 851 * 852 * It's assumed that both values are valid (>= 0). 853 * And, each timespec64 is in normalized form. 854 * 855 * Return: sum of @lhs + @rhs 856 */ 857 struct timespec64 timespec64_add_safe(const struct timespec64 lhs, 858 const struct timespec64 rhs) 859 { 860 struct timespec64 res; 861 862 set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec, 863 lhs.tv_nsec + rhs.tv_nsec); 864 865 if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) { 866 res.tv_sec = TIME64_MAX; 867 res.tv_nsec = 0; 868 } 869 870 return res; 871 } 872 EXPORT_SYMBOL_GPL(timespec64_add_safe); 873 874 /** 875 * get_timespec64 - get user's time value into kernel space 876 * @ts: destination &struct timespec64 877 * @uts: user's time value as &struct __kernel_timespec 878 * 879 * Handles compat or 32-bit modes. 880 * 881 * Return: 0 on success or negative errno on error 882 */ 883 int get_timespec64(struct timespec64 *ts, 884 const struct __kernel_timespec __user *uts) 885 { 886 struct __kernel_timespec kts; 887 int ret; 888 889 ret = copy_from_user(&kts, uts, sizeof(kts)); 890 if (ret) 891 return -EFAULT; 892 893 ts->tv_sec = kts.tv_sec; 894 895 /* Zero out the padding in compat mode */ 896 if (in_compat_syscall()) 897 kts.tv_nsec &= 0xFFFFFFFFUL; 898 899 /* In 32-bit mode, this drops the padding */ 900 ts->tv_nsec = kts.tv_nsec; 901 902 return 0; 903 } 904 EXPORT_SYMBOL_GPL(get_timespec64); 905 906 /** 907 * put_timespec64 - convert timespec64 value to __kernel_timespec format and 908 * copy the latter to userspace 909 * @ts: input &struct timespec64 910 * @uts: user's &struct __kernel_timespec 911 * 912 * Return: 0 on success or negative errno on error 913 */ 914 int put_timespec64(const struct timespec64 *ts, 915 struct __kernel_timespec __user *uts) 916 { 917 struct __kernel_timespec kts = { 918 .tv_sec = ts->tv_sec, 919 .tv_nsec = ts->tv_nsec 920 }; 921 922 return copy_to_user(uts, &kts, sizeof(kts)) ? -EFAULT : 0; 923 } 924 EXPORT_SYMBOL_GPL(put_timespec64); 925 926 static int __get_old_timespec32(struct timespec64 *ts64, 927 const struct old_timespec32 __user *cts) 928 { 929 struct old_timespec32 ts; 930 int ret; 931 932 ret = copy_from_user(&ts, cts, sizeof(ts)); 933 if (ret) 934 return -EFAULT; 935 936 ts64->tv_sec = ts.tv_sec; 937 ts64->tv_nsec = ts.tv_nsec; 938 939 return 0; 940 } 941 942 static int __put_old_timespec32(const struct timespec64 *ts64, 943 struct old_timespec32 __user *cts) 944 { 945 struct old_timespec32 ts = { 946 .tv_sec = ts64->tv_sec, 947 .tv_nsec = ts64->tv_nsec 948 }; 949 return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0; 950 } 951 952 /** 953 * get_old_timespec32 - get user's old-format time value into kernel space 954 * @ts: destination &struct timespec64 955 * @uts: user's old-format time value (&struct old_timespec32) 956 * 957 * Handles X86_X32_ABI compatibility conversion. 958 * 959 * Return: 0 on success or negative errno on error 960 */ 961 int get_old_timespec32(struct timespec64 *ts, const void __user *uts) 962 { 963 if (COMPAT_USE_64BIT_TIME) 964 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; 965 else 966 return __get_old_timespec32(ts, uts); 967 } 968 EXPORT_SYMBOL_GPL(get_old_timespec32); 969 970 /** 971 * put_old_timespec32 - convert timespec64 value to &struct old_timespec32 and 972 * copy the latter to userspace 973 * @ts: input &struct timespec64 974 * @uts: user's &struct old_timespec32 975 * 976 * Handles X86_X32_ABI compatibility conversion. 977 * 978 * Return: 0 on success or negative errno on error 979 */ 980 int put_old_timespec32(const struct timespec64 *ts, void __user *uts) 981 { 982 if (COMPAT_USE_64BIT_TIME) 983 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; 984 else 985 return __put_old_timespec32(ts, uts); 986 } 987 EXPORT_SYMBOL_GPL(put_old_timespec32); 988 989 /** 990 * get_itimerspec64 - get user's &struct __kernel_itimerspec into kernel space 991 * @it: destination &struct itimerspec64 992 * @uit: user's &struct __kernel_itimerspec 993 * 994 * Return: 0 on success or negative errno on error 995 */ 996 int get_itimerspec64(struct itimerspec64 *it, 997 const struct __kernel_itimerspec __user *uit) 998 { 999 int ret; 1000 1001 ret = get_timespec64(&it->it_interval, &uit->it_interval); 1002 if (ret) 1003 return ret; 1004 1005 ret = get_timespec64(&it->it_value, &uit->it_value); 1006 1007 return ret; 1008 } 1009 EXPORT_SYMBOL_GPL(get_itimerspec64); 1010 1011 /** 1012 * put_itimerspec64 - convert &struct itimerspec64 to __kernel_itimerspec format 1013 * and copy the latter to userspace 1014 * @it: input &struct itimerspec64 1015 * @uit: user's &struct __kernel_itimerspec 1016 * 1017 * Return: 0 on success or negative errno on error 1018 */ 1019 int put_itimerspec64(const struct itimerspec64 *it, 1020 struct __kernel_itimerspec __user *uit) 1021 { 1022 int ret; 1023 1024 ret = put_timespec64(&it->it_interval, &uit->it_interval); 1025 if (ret) 1026 return ret; 1027 1028 ret = put_timespec64(&it->it_value, &uit->it_value); 1029 1030 return ret; 1031 } 1032 EXPORT_SYMBOL_GPL(put_itimerspec64); 1033 1034 /** 1035 * get_old_itimerspec32 - get user's &struct old_itimerspec32 into kernel space 1036 * @its: destination &struct itimerspec64 1037 * @uits: user's &struct old_itimerspec32 1038 * 1039 * Return: 0 on success or negative errno on error 1040 */ 1041 int get_old_itimerspec32(struct itimerspec64 *its, 1042 const struct old_itimerspec32 __user *uits) 1043 { 1044 1045 if (__get_old_timespec32(&its->it_interval, &uits->it_interval) || 1046 __get_old_timespec32(&its->it_value, &uits->it_value)) 1047 return -EFAULT; 1048 return 0; 1049 } 1050 EXPORT_SYMBOL_GPL(get_old_itimerspec32); 1051 1052 /** 1053 * put_old_itimerspec32 - convert &struct itimerspec64 to &struct 1054 * old_itimerspec32 and copy the latter to userspace 1055 * @its: input &struct itimerspec64 1056 * @uits: user's &struct old_itimerspec32 1057 * 1058 * Return: 0 on success or negative errno on error 1059 */ 1060 int put_old_itimerspec32(const struct itimerspec64 *its, 1061 struct old_itimerspec32 __user *uits) 1062 { 1063 if (__put_old_timespec32(&its->it_interval, &uits->it_interval) || 1064 __put_old_timespec32(&its->it_value, &uits->it_value)) 1065 return -EFAULT; 1066 return 0; 1067 } 1068 EXPORT_SYMBOL_GPL(put_old_itimerspec32); 1069