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 #include "timekeeping_internal.h" 46 47 #if defined(CONFIG_64BIT) || defined(CONFIG_COMPAT_32BIT_TIME) 48 #define __WANT_OLD_TIME_TYPE_SYSCALL 1 49 #endif 50 51 static_assert(sizeof(__kernel_old_time_t) == 8 ? IS_ENABLED(__WANT_OLD_TIME_TYPE_SYSCALL) : true); 52 53 /* 54 * The timezone where the local system is located. Used as a default by some 55 * programs who obtain this value by using gettimeofday. 56 */ 57 struct timezone sys_tz; 58 59 EXPORT_SYMBOL(sys_tz); 60 61 #if defined(__ARCH_WANT_SYS_TIME) && defined(__WANT_OLD_TIME_TYPE_SYSCALL) 62 63 /* 64 * sys_time() can be implemented in user-level using 65 * sys_gettimeofday(). Is this for backwards compatibility? If so, 66 * why not move it into the appropriate arch directory (for those 67 * architectures that need it). 68 */ 69 SYSCALL_DEFINE1(time, __kernel_old_time_t __user *, tloc) 70 { 71 __kernel_old_time_t i = (__kernel_old_time_t)ktime_get_real_seconds(); 72 73 if (tloc) { 74 if (put_user(i,tloc)) 75 return -EFAULT; 76 } 77 force_successful_syscall_return(); 78 return i; 79 } 80 81 /* 82 * sys_stime() can be implemented in user-level using 83 * sys_settimeofday(). Is this for backwards compatibility? If so, 84 * why not move it into the appropriate arch directory (for those 85 * architectures that need it). 86 */ 87 88 SYSCALL_DEFINE1(stime, __kernel_old_time_t __user *, tptr) 89 { 90 struct timespec64 tv; 91 int err; 92 93 if (get_user(tv.tv_sec, tptr)) 94 return -EFAULT; 95 96 tv.tv_nsec = 0; 97 98 err = security_settime64(&tv, NULL); 99 if (err) 100 return err; 101 102 do_settimeofday64(&tv); 103 return 0; 104 } 105 106 #endif /* __ARCH_WANT_SYS_TIME && __WANT_OLD_TIME_TYPE_SYSCALL */ 107 108 #ifdef CONFIG_COMPAT_32BIT_TIME 109 #ifdef __ARCH_WANT_SYS_TIME32 110 111 /* old_time32_t is a 32 bit "long" and needs to get converted. */ 112 SYSCALL_DEFINE1(time32, old_time32_t __user *, tloc) 113 { 114 old_time32_t i; 115 116 i = (old_time32_t)ktime_get_real_seconds(); 117 118 if (tloc) { 119 if (put_user(i,tloc)) 120 return -EFAULT; 121 } 122 force_successful_syscall_return(); 123 return i; 124 } 125 126 SYSCALL_DEFINE1(stime32, old_time32_t __user *, tptr) 127 { 128 struct timespec64 tv; 129 int err; 130 131 if (get_user(tv.tv_sec, tptr)) 132 return -EFAULT; 133 134 tv.tv_nsec = 0; 135 136 err = security_settime64(&tv, NULL); 137 if (err) 138 return err; 139 140 do_settimeofday64(&tv); 141 return 0; 142 } 143 144 #endif /* __ARCH_WANT_SYS_TIME32 */ 145 #endif 146 147 #ifdef __WANT_OLD_TIME_TYPE_SYSCALL 148 SYSCALL_DEFINE2(gettimeofday, struct __kernel_old_timeval __user *, tv, 149 struct timezone __user *, tz) 150 { 151 if (likely(tv != NULL)) { 152 struct timespec64 ts; 153 154 ktime_get_real_ts64(&ts); 155 if (put_user(ts.tv_sec, &tv->tv_sec) || 156 put_user(ts.tv_nsec / 1000, &tv->tv_usec)) 157 return -EFAULT; 158 } 159 if (unlikely(tz != NULL)) { 160 if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) 161 return -EFAULT; 162 } 163 return 0; 164 } 165 #endif /* __WANT_OLD_TIME_TYPE_SYSCALL */ 166 167 /* 168 * In case for some reason the CMOS clock has not already been running 169 * in UTC, but in some local time: The first time we set the timezone, 170 * we will warp the clock so that it is ticking UTC time instead of 171 * local time. Presumably, if someone is setting the timezone then we 172 * are running in an environment where the programs understand about 173 * timezones. This should be done at boot time in the /etc/rc script, 174 * as soon as possible, so that the clock can be set right. Otherwise, 175 * various programs will get confused when the clock gets warped. 176 */ 177 178 int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz) 179 { 180 static int firsttime = 1; 181 int error = 0; 182 183 if (tv && !timespec64_valid_settod(tv)) 184 return -EINVAL; 185 186 error = security_settime64(tv, tz); 187 if (error) 188 return error; 189 190 if (tz) { 191 /* Verify we're within the +-15 hrs range */ 192 if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60) 193 return -EINVAL; 194 195 sys_tz = *tz; 196 update_vsyscall_tz(); 197 if (firsttime) { 198 firsttime = 0; 199 if (!tv) 200 timekeeping_warp_clock(); 201 } 202 } 203 if (tv) 204 return do_settimeofday64(tv); 205 return 0; 206 } 207 208 SYSCALL_DEFINE2(settimeofday, struct __kernel_old_timeval __user *, tv, 209 struct timezone __user *, tz) 210 { 211 struct timespec64 new_ts; 212 struct timezone new_tz; 213 214 if (tv) { 215 if (!IS_ENABLED(__WANT_OLD_TIME_TYPE_SYSCALL)) 216 return -EINVAL; 217 218 if (get_user(new_ts.tv_sec, &tv->tv_sec) || 219 get_user(new_ts.tv_nsec, &tv->tv_usec)) 220 return -EFAULT; 221 222 if (new_ts.tv_nsec >= USEC_PER_SEC || new_ts.tv_nsec < 0) 223 return -EINVAL; 224 225 new_ts.tv_nsec *= NSEC_PER_USEC; 226 } 227 if (tz) { 228 if (copy_from_user(&new_tz, tz, sizeof(*tz))) 229 return -EFAULT; 230 } 231 232 return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); 233 } 234 235 #ifdef CONFIG_COMPAT_32BIT_TIME 236 COMPAT_SYSCALL_DEFINE2(gettimeofday, struct old_timeval32 __user *, tv, 237 struct timezone __user *, tz) 238 { 239 if (tv) { 240 struct timespec64 ts; 241 242 ktime_get_real_ts64(&ts); 243 if (put_user(ts.tv_sec, &tv->tv_sec) || 244 put_user(ts.tv_nsec / 1000, &tv->tv_usec)) 245 return -EFAULT; 246 } 247 if (tz) { 248 if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) 249 return -EFAULT; 250 } 251 252 return 0; 253 } 254 #endif /* CONFIG_COMPAT_32BIT_TIME */ 255 256 #ifdef CONFIG_COMPAT 257 COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv, 258 struct timezone __user *, tz) 259 { 260 struct timespec64 new_ts; 261 struct timezone new_tz; 262 263 if (tv) { 264 if (!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME)) 265 return -EINVAL; 266 267 if (get_user(new_ts.tv_sec, &tv->tv_sec) || 268 get_user(new_ts.tv_nsec, &tv->tv_usec)) 269 return -EFAULT; 270 271 if (new_ts.tv_nsec >= USEC_PER_SEC || new_ts.tv_nsec < 0) 272 return -EINVAL; 273 274 new_ts.tv_nsec *= NSEC_PER_USEC; 275 } 276 if (tz) { 277 if (copy_from_user(&new_tz, tz, sizeof(*tz))) 278 return -EFAULT; 279 } 280 281 return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); 282 } 283 #endif /* CONFIG_COMPAT */ 284 285 #ifdef CONFIG_64BIT 286 SYSCALL_DEFINE1(adjtimex, struct __kernel_timex __user *, txc_p) 287 { 288 struct __kernel_timex txc; /* Local copy of parameter */ 289 int ret; 290 291 /* Copy the user data space into the kernel copy 292 * structure. But bear in mind that the structures 293 * may change 294 */ 295 if (copy_from_user(&txc, txc_p, sizeof(struct __kernel_timex))) 296 return -EFAULT; 297 ret = do_adjtimex(&txc); 298 return copy_to_user(txc_p, &txc, sizeof(struct __kernel_timex)) ? -EFAULT : ret; 299 } 300 #endif 301 302 #ifdef CONFIG_COMPAT_32BIT_TIME 303 int get_old_timex32(struct __kernel_timex *txc, const struct old_timex32 __user *utp) 304 { 305 struct old_timex32 tx32; 306 307 memset(txc, 0, sizeof(struct __kernel_timex)); 308 if (copy_from_user(&tx32, utp, sizeof(struct old_timex32))) 309 return -EFAULT; 310 311 txc->modes = tx32.modes; 312 txc->offset = tx32.offset; 313 txc->freq = tx32.freq; 314 txc->maxerror = tx32.maxerror; 315 txc->esterror = tx32.esterror; 316 txc->status = tx32.status; 317 txc->constant = tx32.constant; 318 txc->precision = tx32.precision; 319 txc->tolerance = tx32.tolerance; 320 txc->time.tv_sec = tx32.time.tv_sec; 321 txc->time.tv_usec = tx32.time.tv_usec; 322 txc->tick = tx32.tick; 323 txc->ppsfreq = tx32.ppsfreq; 324 txc->jitter = tx32.jitter; 325 txc->shift = tx32.shift; 326 txc->stabil = tx32.stabil; 327 txc->jitcnt = tx32.jitcnt; 328 txc->calcnt = tx32.calcnt; 329 txc->errcnt = tx32.errcnt; 330 txc->stbcnt = tx32.stbcnt; 331 332 return 0; 333 } 334 335 int put_old_timex32(struct old_timex32 __user *utp, const struct __kernel_timex *txc) 336 { 337 struct old_timex32 tx32; 338 339 memset(&tx32, 0, sizeof(struct old_timex32)); 340 tx32.modes = txc->modes; 341 tx32.offset = txc->offset; 342 tx32.freq = txc->freq; 343 tx32.maxerror = txc->maxerror; 344 tx32.esterror = txc->esterror; 345 tx32.status = txc->status; 346 tx32.constant = txc->constant; 347 tx32.precision = txc->precision; 348 tx32.tolerance = txc->tolerance; 349 tx32.time.tv_sec = txc->time.tv_sec; 350 tx32.time.tv_usec = txc->time.tv_usec; 351 tx32.tick = txc->tick; 352 tx32.ppsfreq = txc->ppsfreq; 353 tx32.jitter = txc->jitter; 354 tx32.shift = txc->shift; 355 tx32.stabil = txc->stabil; 356 tx32.jitcnt = txc->jitcnt; 357 tx32.calcnt = txc->calcnt; 358 tx32.errcnt = txc->errcnt; 359 tx32.stbcnt = txc->stbcnt; 360 tx32.tai = txc->tai; 361 if (copy_to_user(utp, &tx32, sizeof(struct old_timex32))) 362 return -EFAULT; 363 return 0; 364 } 365 366 SYSCALL_DEFINE1(adjtimex_time32, struct old_timex32 __user *, utp) 367 { 368 struct __kernel_timex txc; 369 int err, ret; 370 371 err = get_old_timex32(&txc, utp); 372 if (err) 373 return err; 374 375 ret = do_adjtimex(&txc); 376 377 err = put_old_timex32(utp, &txc); 378 if (err) 379 return err; 380 381 return ret; 382 } 383 #endif 384 385 #if HZ > MSEC_PER_SEC || (MSEC_PER_SEC % HZ) 386 /** 387 * jiffies_to_msecs - Convert jiffies to milliseconds 388 * @j: jiffies value 389 * 390 * Return: milliseconds value 391 */ 392 unsigned int jiffies_to_msecs(const unsigned long j) 393 { 394 #if HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) 395 return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); 396 #else 397 # if BITS_PER_LONG == 32 398 return (HZ_TO_MSEC_MUL32 * j + (1ULL << HZ_TO_MSEC_SHR32) - 1) >> 399 HZ_TO_MSEC_SHR32; 400 # else 401 return DIV_ROUND_UP(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); 402 # endif 403 #endif 404 } 405 EXPORT_SYMBOL(jiffies_to_msecs); 406 #endif 407 408 #if (USEC_PER_SEC % HZ) 409 /** 410 * jiffies_to_usecs - Convert jiffies to microseconds 411 * @j: jiffies value 412 * 413 * Return: microseconds value 414 */ 415 unsigned int jiffies_to_usecs(const unsigned long j) 416 { 417 /* 418 * Hz usually doesn't go much further MSEC_PER_SEC. 419 * jiffies_to_usecs() and usecs_to_jiffies() depend on that. 420 */ 421 BUILD_BUG_ON(HZ > USEC_PER_SEC); 422 423 #if BITS_PER_LONG == 32 424 return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; 425 #else 426 return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; 427 #endif 428 } 429 EXPORT_SYMBOL(jiffies_to_usecs); 430 #endif 431 432 /** 433 * mktime64 - Converts date to seconds. 434 * @year0: year to convert 435 * @mon0: month to convert 436 * @day: day to convert 437 * @hour: hour to convert 438 * @min: minute to convert 439 * @sec: second to convert 440 * 441 * Converts Gregorian date to seconds since 1970-01-01 00:00:00. 442 * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 443 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. 444 * 445 * [For the Julian calendar (which was used in Russia before 1917, 446 * Britain & colonies before 1752, anywhere else before 1582, 447 * and is still in use by some communities) leave out the 448 * -year/100+year/400 terms, and add 10.] 449 * 450 * This algorithm was first published by Gauss (I think). 451 * 452 * A leap second can be indicated by calling this function with sec as 453 * 60 (allowable under ISO 8601). The leap second is treated the same 454 * as the following second since they don't exist in UNIX time. 455 * 456 * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight 457 * tomorrow - (allowable under ISO 8601) is supported. 458 * 459 * Return: seconds since the epoch time for the given input date 460 */ 461 time64_t mktime64(const unsigned int year0, const unsigned int mon0, 462 const unsigned int day, const unsigned int hour, 463 const unsigned int min, const unsigned int sec) 464 { 465 unsigned int mon = mon0, year = year0; 466 467 /* 1..12 -> 11,12,1..10 */ 468 if (0 >= (int) (mon -= 2)) { 469 mon += 12; /* Puts Feb last since it has leap day */ 470 year -= 1; 471 } 472 473 return ((((time64_t) 474 (year/4 - year/100 + year/400 + 367*mon/12 + day) + 475 year*365 - 719499 476 )*24 + hour /* now have hours - midnight tomorrow handled here */ 477 )*60 + min /* now have minutes */ 478 )*60 + sec; /* finally seconds */ 479 } 480 EXPORT_SYMBOL(mktime64); 481 482 struct __kernel_old_timeval ns_to_kernel_old_timeval(s64 nsec) 483 { 484 struct timespec64 ts = ns_to_timespec64(nsec); 485 struct __kernel_old_timeval tv; 486 487 tv.tv_sec = ts.tv_sec; 488 tv.tv_usec = (suseconds_t)ts.tv_nsec / 1000; 489 490 return tv; 491 } 492 EXPORT_SYMBOL(ns_to_kernel_old_timeval); 493 494 /** 495 * set_normalized_timespec64 - set timespec sec and nsec parts and normalize 496 * 497 * @ts: pointer to timespec variable to be set 498 * @sec: seconds to set 499 * @nsec: nanoseconds to set 500 * 501 * Set seconds and nanoseconds field of a timespec variable and 502 * normalize to the timespec storage format 503 * 504 * Note: The tv_nsec part is always in the range of 0 <= tv_nsec < NSEC_PER_SEC. 505 * For negative values only the tv_sec field is negative ! 506 */ 507 void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec) 508 { 509 while (nsec >= NSEC_PER_SEC) { 510 /* 511 * The following asm() prevents the compiler from 512 * optimising this loop into a modulo operation. See 513 * also __iter_div_u64_rem() in include/linux/time.h 514 */ 515 asm("" : "+rm"(nsec)); 516 nsec -= NSEC_PER_SEC; 517 ++sec; 518 } 519 while (nsec < 0) { 520 asm("" : "+rm"(nsec)); 521 nsec += NSEC_PER_SEC; 522 --sec; 523 } 524 ts->tv_sec = sec; 525 ts->tv_nsec = nsec; 526 } 527 EXPORT_SYMBOL(set_normalized_timespec64); 528 529 /** 530 * ns_to_timespec64 - Convert nanoseconds to timespec64 531 * @nsec: the nanoseconds value to be converted 532 * 533 * Return: the timespec64 representation of the nsec parameter. 534 */ 535 struct timespec64 ns_to_timespec64(s64 nsec) 536 { 537 struct timespec64 ts = { 0, 0 }; 538 s32 rem; 539 540 if (likely(nsec > 0)) { 541 ts.tv_sec = div_u64_rem(nsec, NSEC_PER_SEC, &rem); 542 ts.tv_nsec = rem; 543 } else if (nsec < 0) { 544 /* 545 * With negative times, tv_sec points to the earlier 546 * second, and tv_nsec counts the nanoseconds since 547 * then, so tv_nsec is always a positive number. 548 */ 549 ts.tv_sec = -div_u64_rem(-nsec - 1, NSEC_PER_SEC, &rem) - 1; 550 ts.tv_nsec = NSEC_PER_SEC - rem - 1; 551 } 552 553 return ts; 554 } 555 EXPORT_SYMBOL(ns_to_timespec64); 556 557 /** 558 * __msecs_to_jiffies: - convert milliseconds to jiffies 559 * @m: time in milliseconds 560 * 561 * conversion is done as follows: 562 * 563 * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) 564 * 565 * - 'too large' values [that would result in larger than 566 * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. 567 * 568 * - all other values are converted to jiffies by either multiplying 569 * the input value by a factor or dividing it with a factor and 570 * handling any 32-bit overflows. 571 * for the details see _msecs_to_jiffies() 572 * 573 * msecs_to_jiffies() checks for the passed in value being a constant 574 * via __builtin_constant_p() allowing gcc to eliminate most of the 575 * code, __msecs_to_jiffies() is called if the value passed does not 576 * allow constant folding and the actual conversion must be done at 577 * runtime. 578 * The _msecs_to_jiffies helpers are the HZ dependent conversion 579 * routines found in include/linux/jiffies.h 580 * 581 * Return: jiffies value 582 */ 583 unsigned long __msecs_to_jiffies(const unsigned int m) 584 { 585 /* 586 * Negative value, means infinite timeout: 587 */ 588 if ((int)m < 0) 589 return MAX_JIFFY_OFFSET; 590 return _msecs_to_jiffies(m); 591 } 592 EXPORT_SYMBOL(__msecs_to_jiffies); 593 594 /** 595 * __usecs_to_jiffies: - convert microseconds to jiffies 596 * @u: time in milliseconds 597 * 598 * Return: jiffies value 599 */ 600 unsigned long __usecs_to_jiffies(const unsigned int u) 601 { 602 if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) 603 return MAX_JIFFY_OFFSET; 604 return _usecs_to_jiffies(u); 605 } 606 EXPORT_SYMBOL(__usecs_to_jiffies); 607 608 /** 609 * timespec64_to_jiffies - convert a timespec64 value to jiffies 610 * @value: pointer to &struct timespec64 611 * 612 * The TICK_NSEC - 1 rounds up the value to the next resolution. Note 613 * that a remainder subtract here would not do the right thing as the 614 * resolution values don't fall on second boundaries. I.e. the line: 615 * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding. 616 * Note that due to the small error in the multiplier here, this 617 * rounding is incorrect for sufficiently large values of tv_nsec, but 618 * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're 619 * OK. 620 * 621 * Rather, we just shift the bits off the right. 622 * 623 * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec 624 * value to a scaled second value. 625 * 626 * Return: jiffies value 627 */ 628 unsigned long 629 timespec64_to_jiffies(const struct timespec64 *value) 630 { 631 u64 sec = value->tv_sec; 632 long nsec = value->tv_nsec + TICK_NSEC - 1; 633 634 if (sec >= MAX_SEC_IN_JIFFIES){ 635 sec = MAX_SEC_IN_JIFFIES; 636 nsec = 0; 637 } 638 return ((sec * SEC_CONVERSION) + 639 (((u64)nsec * NSEC_CONVERSION) >> 640 (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; 641 642 } 643 EXPORT_SYMBOL(timespec64_to_jiffies); 644 645 /** 646 * jiffies_to_timespec64 - convert jiffies value to &struct timespec64 647 * @jiffies: jiffies value 648 * @value: pointer to &struct timespec64 649 */ 650 void 651 jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value) 652 { 653 /* 654 * Convert jiffies to nanoseconds and separate with 655 * one divide. 656 */ 657 u32 rem; 658 value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, 659 NSEC_PER_SEC, &rem); 660 value->tv_nsec = rem; 661 } 662 EXPORT_SYMBOL(jiffies_to_timespec64); 663 664 /* 665 * Convert jiffies/jiffies_64 to clock_t and back. 666 */ 667 668 /** 669 * jiffies_to_clock_t - Convert jiffies to clock_t 670 * @x: jiffies value 671 * 672 * Return: jiffies converted to clock_t (CLOCKS_PER_SEC) 673 */ 674 clock_t jiffies_to_clock_t(unsigned long x) 675 { 676 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 677 # if HZ < USER_HZ 678 return x * (USER_HZ / HZ); 679 # else 680 return x / (HZ / USER_HZ); 681 # endif 682 #else 683 return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ); 684 #endif 685 } 686 EXPORT_SYMBOL(jiffies_to_clock_t); 687 688 /** 689 * clock_t_to_jiffies - Convert clock_t to jiffies 690 * @x: clock_t value 691 * 692 * Return: clock_t value converted to jiffies 693 */ 694 unsigned long clock_t_to_jiffies(unsigned long x) 695 { 696 #if (HZ % USER_HZ)==0 697 if (x >= ~0UL / (HZ / USER_HZ)) 698 return ~0UL; 699 return x * (HZ / USER_HZ); 700 #else 701 /* Don't worry about loss of precision here .. */ 702 if (x >= ~0UL / HZ * USER_HZ) 703 return ~0UL; 704 705 /* .. but do try to contain it here */ 706 return div_u64((u64)x * HZ, USER_HZ); 707 #endif 708 } 709 EXPORT_SYMBOL(clock_t_to_jiffies); 710 711 /** 712 * jiffies_64_to_clock_t - Convert jiffies_64 to clock_t 713 * @x: jiffies_64 value 714 * 715 * Return: jiffies_64 value converted to 64-bit "clock_t" (CLOCKS_PER_SEC) 716 */ 717 notrace u64 jiffies_64_to_clock_t(u64 x) 718 { 719 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 720 # if HZ < USER_HZ 721 x = div_u64(x * USER_HZ, HZ); 722 # elif HZ > USER_HZ 723 x = div_u64(x, HZ / USER_HZ); 724 # else 725 /* Nothing to do */ 726 # endif 727 #else 728 /* 729 * There are better ways that don't overflow early, 730 * but even this doesn't overflow in hundreds of years 731 * in 64 bits, so.. 732 */ 733 x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ)); 734 #endif 735 return x; 736 } 737 EXPORT_SYMBOL(jiffies_64_to_clock_t); 738 739 /** 740 * nsec_to_clock_t - Convert nsec value to clock_t 741 * @x: nsec value 742 * 743 * Return: nsec value converted to 64-bit "clock_t" (CLOCKS_PER_SEC) 744 */ 745 u64 nsec_to_clock_t(u64 x) 746 { 747 #if (NSEC_PER_SEC % USER_HZ) == 0 748 return div_u64(x, NSEC_PER_SEC / USER_HZ); 749 #elif (USER_HZ % 512) == 0 750 return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512); 751 #else 752 /* 753 * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024, 754 * overflow after 64.99 years. 755 * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ... 756 */ 757 return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ); 758 #endif 759 } 760 761 /** 762 * jiffies64_to_nsecs - Convert jiffies64 to nanoseconds 763 * @j: jiffies64 value 764 * 765 * Return: nanoseconds value 766 */ 767 u64 jiffies64_to_nsecs(u64 j) 768 { 769 #if !(NSEC_PER_SEC % HZ) 770 return (NSEC_PER_SEC / HZ) * j; 771 # else 772 return div_u64(j * HZ_TO_NSEC_NUM, HZ_TO_NSEC_DEN); 773 #endif 774 } 775 EXPORT_SYMBOL(jiffies64_to_nsecs); 776 777 /** 778 * jiffies64_to_msecs - Convert jiffies64 to milliseconds 779 * @j: jiffies64 value 780 * 781 * Return: milliseconds value 782 */ 783 u64 jiffies64_to_msecs(const u64 j) 784 { 785 #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) 786 return (MSEC_PER_SEC / HZ) * j; 787 #else 788 return div_u64(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); 789 #endif 790 } 791 EXPORT_SYMBOL(jiffies64_to_msecs); 792 793 /** 794 * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 795 * 796 * @n: nsecs in u64 797 * 798 * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. 799 * And this doesn't return MAX_JIFFY_OFFSET since this function is designed 800 * for scheduler, not for use in device drivers to calculate timeout value. 801 * 802 * note: 803 * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) 804 * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years 805 * 806 * Return: nsecs converted to jiffies64 value 807 */ 808 u64 nsecs_to_jiffies64(u64 n) 809 { 810 #if (NSEC_PER_SEC % HZ) == 0 811 /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ 812 return div_u64(n, NSEC_PER_SEC / HZ); 813 #elif (HZ % 512) == 0 814 /* overflow after 292 years if HZ = 1024 */ 815 return div_u64(n * HZ / 512, NSEC_PER_SEC / 512); 816 #else 817 /* 818 * Generic case - optimized for cases where HZ is a multiple of 3. 819 * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc. 820 */ 821 return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); 822 #endif 823 } 824 EXPORT_SYMBOL(nsecs_to_jiffies64); 825 826 /** 827 * nsecs_to_jiffies - Convert nsecs in u64 to jiffies 828 * 829 * @n: nsecs in u64 830 * 831 * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. 832 * And this doesn't return MAX_JIFFY_OFFSET since this function is designed 833 * for scheduler, not for use in device drivers to calculate timeout value. 834 * 835 * note: 836 * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) 837 * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years 838 * 839 * Return: nsecs converted to jiffies value 840 */ 841 unsigned long nsecs_to_jiffies(u64 n) 842 { 843 return (unsigned long)nsecs_to_jiffies64(n); 844 } 845 EXPORT_SYMBOL_GPL(nsecs_to_jiffies); 846 847 /** 848 * timespec64_add_safe - Add two timespec64 values and do a safety check 849 * for overflow. 850 * @lhs: first (left) timespec64 to add 851 * @rhs: second (right) timespec64 to add 852 * 853 * It's assumed that both values are valid (>= 0). 854 * And, each timespec64 is in normalized form. 855 * 856 * Return: sum of @lhs + @rhs 857 */ 858 struct timespec64 timespec64_add_safe(const struct timespec64 lhs, 859 const struct timespec64 rhs) 860 { 861 struct timespec64 res; 862 863 set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec, 864 lhs.tv_nsec + rhs.tv_nsec); 865 866 if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) { 867 res.tv_sec = TIME64_MAX; 868 res.tv_nsec = 0; 869 } 870 871 return res; 872 } 873 EXPORT_SYMBOL_GPL(timespec64_add_safe); 874 875 /** 876 * get_timespec64 - get user's time value into kernel space 877 * @ts: destination &struct timespec64 878 * @uts: user's time value as &struct __kernel_timespec 879 * 880 * Handles compat or 32-bit modes. 881 * 882 * Return: 0 on success or negative errno on error 883 */ 884 int get_timespec64(struct timespec64 *ts, 885 const struct __kernel_timespec __user *uts) 886 { 887 struct __kernel_timespec kts; 888 int ret; 889 890 ret = copy_from_user(&kts, uts, sizeof(kts)); 891 if (ret) 892 return -EFAULT; 893 894 ts->tv_sec = kts.tv_sec; 895 896 /* Zero out the padding in compat mode */ 897 if (in_compat_syscall()) 898 kts.tv_nsec &= 0xFFFFFFFFUL; 899 900 /* In 32-bit mode, this drops the padding */ 901 ts->tv_nsec = kts.tv_nsec; 902 903 return 0; 904 } 905 EXPORT_SYMBOL_GPL(get_timespec64); 906 907 /** 908 * put_timespec64 - convert timespec64 value to __kernel_timespec format and 909 * copy the latter to userspace 910 * @ts: input &struct timespec64 911 * @uts: user's &struct __kernel_timespec 912 * 913 * Return: 0 on success or negative errno on error 914 */ 915 int put_timespec64(const struct timespec64 *ts, 916 struct __kernel_timespec __user *uts) 917 { 918 struct __kernel_timespec kts = { 919 .tv_sec = ts->tv_sec, 920 .tv_nsec = ts->tv_nsec 921 }; 922 923 return copy_to_user(uts, &kts, sizeof(kts)) ? -EFAULT : 0; 924 } 925 EXPORT_SYMBOL_GPL(put_timespec64); 926 927 static int __get_old_timespec32(struct timespec64 *ts64, 928 const struct old_timespec32 __user *cts) 929 { 930 struct old_timespec32 ts; 931 int ret; 932 933 ret = copy_from_user(&ts, cts, sizeof(ts)); 934 if (ret) 935 return -EFAULT; 936 937 ts64->tv_sec = ts.tv_sec; 938 ts64->tv_nsec = ts.tv_nsec; 939 940 return 0; 941 } 942 943 static int __put_old_timespec32(const struct timespec64 *ts64, 944 struct old_timespec32 __user *cts) 945 { 946 struct old_timespec32 ts = { 947 .tv_sec = ts64->tv_sec, 948 .tv_nsec = ts64->tv_nsec 949 }; 950 return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0; 951 } 952 953 /** 954 * get_old_timespec32 - get user's old-format time value into kernel space 955 * @ts: destination &struct timespec64 956 * @uts: user's old-format time value (&struct old_timespec32) 957 * 958 * Handles X86_X32_ABI compatibility conversion. 959 * 960 * Return: 0 on success or negative errno on error 961 */ 962 int get_old_timespec32(struct timespec64 *ts, const void __user *uts) 963 { 964 if (COMPAT_USE_64BIT_TIME) 965 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; 966 else 967 return __get_old_timespec32(ts, uts); 968 } 969 EXPORT_SYMBOL_GPL(get_old_timespec32); 970 971 /** 972 * put_old_timespec32 - convert timespec64 value to &struct old_timespec32 and 973 * copy the latter to userspace 974 * @ts: input &struct timespec64 975 * @uts: user's &struct old_timespec32 976 * 977 * Handles X86_X32_ABI compatibility conversion. 978 * 979 * Return: 0 on success or negative errno on error 980 */ 981 int put_old_timespec32(const struct timespec64 *ts, void __user *uts) 982 { 983 if (COMPAT_USE_64BIT_TIME) 984 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; 985 else 986 return __put_old_timespec32(ts, uts); 987 } 988 EXPORT_SYMBOL_GPL(put_old_timespec32); 989 990 /** 991 * get_itimerspec64 - get user's &struct __kernel_itimerspec into kernel space 992 * @it: destination &struct itimerspec64 993 * @uit: user's &struct __kernel_itimerspec 994 * 995 * Return: 0 on success or negative errno on error 996 */ 997 int get_itimerspec64(struct itimerspec64 *it, 998 const struct __kernel_itimerspec __user *uit) 999 { 1000 int ret; 1001 1002 ret = get_timespec64(&it->it_interval, &uit->it_interval); 1003 if (ret) 1004 return ret; 1005 1006 ret = get_timespec64(&it->it_value, &uit->it_value); 1007 1008 return ret; 1009 } 1010 EXPORT_SYMBOL_GPL(get_itimerspec64); 1011 1012 /** 1013 * put_itimerspec64 - convert &struct itimerspec64 to __kernel_itimerspec format 1014 * and copy the latter to userspace 1015 * @it: input &struct itimerspec64 1016 * @uit: user's &struct __kernel_itimerspec 1017 * 1018 * Return: 0 on success or negative errno on error 1019 */ 1020 int put_itimerspec64(const struct itimerspec64 *it, 1021 struct __kernel_itimerspec __user *uit) 1022 { 1023 int ret; 1024 1025 ret = put_timespec64(&it->it_interval, &uit->it_interval); 1026 if (ret) 1027 return ret; 1028 1029 ret = put_timespec64(&it->it_value, &uit->it_value); 1030 1031 return ret; 1032 } 1033 EXPORT_SYMBOL_GPL(put_itimerspec64); 1034 1035 /** 1036 * get_old_itimerspec32 - get user's &struct old_itimerspec32 into kernel space 1037 * @its: destination &struct itimerspec64 1038 * @uits: user's &struct old_itimerspec32 1039 * 1040 * Return: 0 on success or negative errno on error 1041 */ 1042 int get_old_itimerspec32(struct itimerspec64 *its, 1043 const struct old_itimerspec32 __user *uits) 1044 { 1045 1046 if (__get_old_timespec32(&its->it_interval, &uits->it_interval) || 1047 __get_old_timespec32(&its->it_value, &uits->it_value)) 1048 return -EFAULT; 1049 return 0; 1050 } 1051 EXPORT_SYMBOL_GPL(get_old_itimerspec32); 1052 1053 /** 1054 * put_old_itimerspec32 - convert &struct itimerspec64 to &struct 1055 * old_itimerspec32 and copy the latter to userspace 1056 * @its: input &struct itimerspec64 1057 * @uits: user's &struct old_itimerspec32 1058 * 1059 * Return: 0 on success or negative errno on error 1060 */ 1061 int put_old_itimerspec32(const struct itimerspec64 *its, 1062 struct old_itimerspec32 __user *uits) 1063 { 1064 if (__put_old_timespec32(&its->it_interval, &uits->it_interval) || 1065 __put_old_timespec32(&its->it_value, &uits->it_value)) 1066 return -EFAULT; 1067 return 0; 1068 } 1069 EXPORT_SYMBOL_GPL(put_old_itimerspec32); 1070