1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 1991, 1992 Linus Torvalds 4 * 5 * This file contains the interface functions for the various time related 6 * system calls: time, stime, gettimeofday, settimeofday, adjtime 7 * 8 * Modification history: 9 * 10 * 1993-09-02 Philip Gladstone 11 * Created file with time related functions from sched/core.c and adjtimex() 12 * 1993-10-08 Torsten Duwe 13 * adjtime interface update and CMOS clock write code 14 * 1995-08-13 Torsten Duwe 15 * kernel PLL updated to 1994-12-13 specs (rfc-1589) 16 * 1999-01-16 Ulrich Windl 17 * Introduced error checking for many cases in adjtimex(). 18 * Updated NTP code according to technical memorandum Jan '96 19 * "A Kernel Model for Precision Timekeeping" by Dave Mills 20 * Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10) 21 * (Even though the technical memorandum forbids it) 22 * 2004-07-14 Christoph Lameter 23 * Added getnstimeofday to allow the posix timer functions to return 24 * with nanosecond accuracy 25 */ 26 27 #include <linux/export.h> 28 #include <linux/kernel.h> 29 #include <linux/timex.h> 30 #include <linux/capability.h> 31 #include <linux/timekeeper_internal.h> 32 #include <linux/errno.h> 33 #include <linux/syscalls.h> 34 #include <linux/security.h> 35 #include <linux/fs.h> 36 #include <linux/math64.h> 37 #include <linux/ptrace.h> 38 39 #include <linux/uaccess.h> 40 #include <linux/compat.h> 41 #include <asm/unistd.h> 42 43 #include <generated/timeconst.h> 44 #include "timekeeping.h" 45 46 /* 47 * The timezone where the local system is located. Used as a default by some 48 * programs who obtain this value by using gettimeofday. 49 */ 50 struct timezone sys_tz; 51 52 EXPORT_SYMBOL(sys_tz); 53 54 #ifdef __ARCH_WANT_SYS_TIME 55 56 /* 57 * sys_time() can be implemented in user-level using 58 * sys_gettimeofday(). Is this for backwards compatibility? If so, 59 * why not move it into the appropriate arch directory (for those 60 * architectures that need it). 61 */ 62 SYSCALL_DEFINE1(time, time_t __user *, tloc) 63 { 64 time_t i = (time_t)ktime_get_real_seconds(); 65 66 if (tloc) { 67 if (put_user(i,tloc)) 68 return -EFAULT; 69 } 70 force_successful_syscall_return(); 71 return i; 72 } 73 74 /* 75 * sys_stime() can be implemented in user-level using 76 * sys_settimeofday(). Is this for backwards compatibility? If so, 77 * why not move it into the appropriate arch directory (for those 78 * architectures that need it). 79 */ 80 81 SYSCALL_DEFINE1(stime, time_t __user *, tptr) 82 { 83 struct timespec64 tv; 84 int err; 85 86 if (get_user(tv.tv_sec, tptr)) 87 return -EFAULT; 88 89 tv.tv_nsec = 0; 90 91 err = security_settime64(&tv, NULL); 92 if (err) 93 return err; 94 95 do_settimeofday64(&tv); 96 return 0; 97 } 98 99 #endif /* __ARCH_WANT_SYS_TIME */ 100 101 #ifdef CONFIG_COMPAT 102 #ifdef __ARCH_WANT_COMPAT_SYS_TIME 103 104 /* old_time32_t is a 32 bit "long" and needs to get converted. */ 105 COMPAT_SYSCALL_DEFINE1(time, old_time32_t __user *, tloc) 106 { 107 old_time32_t i; 108 109 i = (old_time32_t)ktime_get_real_seconds(); 110 111 if (tloc) { 112 if (put_user(i,tloc)) 113 return -EFAULT; 114 } 115 force_successful_syscall_return(); 116 return i; 117 } 118 119 COMPAT_SYSCALL_DEFINE1(stime, old_time32_t __user *, tptr) 120 { 121 struct timespec64 tv; 122 int err; 123 124 if (get_user(tv.tv_sec, tptr)) 125 return -EFAULT; 126 127 tv.tv_nsec = 0; 128 129 err = security_settime64(&tv, NULL); 130 if (err) 131 return err; 132 133 do_settimeofday64(&tv); 134 return 0; 135 } 136 137 #endif /* __ARCH_WANT_COMPAT_SYS_TIME */ 138 #endif 139 140 SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv, 141 struct timezone __user *, tz) 142 { 143 if (likely(tv != NULL)) { 144 struct timespec64 ts; 145 146 ktime_get_real_ts64(&ts); 147 if (put_user(ts.tv_sec, &tv->tv_sec) || 148 put_user(ts.tv_nsec / 1000, &tv->tv_usec)) 149 return -EFAULT; 150 } 151 if (unlikely(tz != NULL)) { 152 if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) 153 return -EFAULT; 154 } 155 return 0; 156 } 157 158 /* 159 * In case for some reason the CMOS clock has not already been running 160 * in UTC, but in some local time: The first time we set the timezone, 161 * we will warp the clock so that it is ticking UTC time instead of 162 * local time. Presumably, if someone is setting the timezone then we 163 * are running in an environment where the programs understand about 164 * timezones. This should be done at boot time in the /etc/rc script, 165 * as soon as possible, so that the clock can be set right. Otherwise, 166 * various programs will get confused when the clock gets warped. 167 */ 168 169 int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz) 170 { 171 static int firsttime = 1; 172 int error = 0; 173 174 if (tv && !timespec64_valid(tv)) 175 return -EINVAL; 176 177 error = security_settime64(tv, tz); 178 if (error) 179 return error; 180 181 if (tz) { 182 /* Verify we're witin the +-15 hrs range */ 183 if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60) 184 return -EINVAL; 185 186 sys_tz = *tz; 187 update_vsyscall_tz(); 188 if (firsttime) { 189 firsttime = 0; 190 if (!tv) 191 timekeeping_warp_clock(); 192 } 193 } 194 if (tv) 195 return do_settimeofday64(tv); 196 return 0; 197 } 198 199 SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv, 200 struct timezone __user *, tz) 201 { 202 struct timespec64 new_ts; 203 struct timeval user_tv; 204 struct timezone new_tz; 205 206 if (tv) { 207 if (copy_from_user(&user_tv, tv, sizeof(*tv))) 208 return -EFAULT; 209 210 if (!timeval_valid(&user_tv)) 211 return -EINVAL; 212 213 new_ts.tv_sec = user_tv.tv_sec; 214 new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; 215 } 216 if (tz) { 217 if (copy_from_user(&new_tz, tz, sizeof(*tz))) 218 return -EFAULT; 219 } 220 221 return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); 222 } 223 224 #ifdef CONFIG_COMPAT 225 COMPAT_SYSCALL_DEFINE2(gettimeofday, struct old_timeval32 __user *, tv, 226 struct timezone __user *, tz) 227 { 228 if (tv) { 229 struct timespec64 ts; 230 231 ktime_get_real_ts64(&ts); 232 if (put_user(ts.tv_sec, &tv->tv_sec) || 233 put_user(ts.tv_nsec / 1000, &tv->tv_usec)) 234 return -EFAULT; 235 } 236 if (tz) { 237 if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) 238 return -EFAULT; 239 } 240 241 return 0; 242 } 243 244 COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv, 245 struct timezone __user *, tz) 246 { 247 struct timespec64 new_ts; 248 struct timeval user_tv; 249 struct timezone new_tz; 250 251 if (tv) { 252 if (compat_get_timeval(&user_tv, tv)) 253 return -EFAULT; 254 new_ts.tv_sec = user_tv.tv_sec; 255 new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; 256 } 257 if (tz) { 258 if (copy_from_user(&new_tz, tz, sizeof(*tz))) 259 return -EFAULT; 260 } 261 262 return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); 263 } 264 #endif 265 266 SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p) 267 { 268 struct timex txc; /* Local copy of parameter */ 269 int ret; 270 271 /* Copy the user data space into the kernel copy 272 * structure. But bear in mind that the structures 273 * may change 274 */ 275 if (copy_from_user(&txc, txc_p, sizeof(struct timex))) 276 return -EFAULT; 277 ret = do_adjtimex(&txc); 278 return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret; 279 } 280 281 #ifdef CONFIG_COMPAT 282 283 COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp) 284 { 285 struct timex txc; 286 int err, ret; 287 288 err = compat_get_timex(&txc, utp); 289 if (err) 290 return err; 291 292 ret = do_adjtimex(&txc); 293 294 err = compat_put_timex(utp, &txc); 295 if (err) 296 return err; 297 298 return ret; 299 } 300 #endif 301 302 /* 303 * Convert jiffies to milliseconds and back. 304 * 305 * Avoid unnecessary multiplications/divisions in the 306 * two most common HZ cases: 307 */ 308 unsigned int jiffies_to_msecs(const unsigned long j) 309 { 310 #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) 311 return (MSEC_PER_SEC / HZ) * j; 312 #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) 313 return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); 314 #else 315 # if BITS_PER_LONG == 32 316 return (HZ_TO_MSEC_MUL32 * j + (1ULL << HZ_TO_MSEC_SHR32) - 1) >> 317 HZ_TO_MSEC_SHR32; 318 # else 319 return DIV_ROUND_UP(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); 320 # endif 321 #endif 322 } 323 EXPORT_SYMBOL(jiffies_to_msecs); 324 325 unsigned int jiffies_to_usecs(const unsigned long j) 326 { 327 /* 328 * Hz usually doesn't go much further MSEC_PER_SEC. 329 * jiffies_to_usecs() and usecs_to_jiffies() depend on that. 330 */ 331 BUILD_BUG_ON(HZ > USEC_PER_SEC); 332 333 #if !(USEC_PER_SEC % HZ) 334 return (USEC_PER_SEC / HZ) * j; 335 #else 336 # if BITS_PER_LONG == 32 337 return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; 338 # else 339 return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; 340 # endif 341 #endif 342 } 343 EXPORT_SYMBOL(jiffies_to_usecs); 344 345 /* 346 * mktime64 - Converts date to seconds. 347 * Converts Gregorian date to seconds since 1970-01-01 00:00:00. 348 * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 349 * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. 350 * 351 * [For the Julian calendar (which was used in Russia before 1917, 352 * Britain & colonies before 1752, anywhere else before 1582, 353 * and is still in use by some communities) leave out the 354 * -year/100+year/400 terms, and add 10.] 355 * 356 * This algorithm was first published by Gauss (I think). 357 * 358 * A leap second can be indicated by calling this function with sec as 359 * 60 (allowable under ISO 8601). The leap second is treated the same 360 * as the following second since they don't exist in UNIX time. 361 * 362 * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight 363 * tomorrow - (allowable under ISO 8601) is supported. 364 */ 365 time64_t mktime64(const unsigned int year0, const unsigned int mon0, 366 const unsigned int day, const unsigned int hour, 367 const unsigned int min, const unsigned int sec) 368 { 369 unsigned int mon = mon0, year = year0; 370 371 /* 1..12 -> 11,12,1..10 */ 372 if (0 >= (int) (mon -= 2)) { 373 mon += 12; /* Puts Feb last since it has leap day */ 374 year -= 1; 375 } 376 377 return ((((time64_t) 378 (year/4 - year/100 + year/400 + 367*mon/12 + day) + 379 year*365 - 719499 380 )*24 + hour /* now have hours - midnight tomorrow handled here */ 381 )*60 + min /* now have minutes */ 382 )*60 + sec; /* finally seconds */ 383 } 384 EXPORT_SYMBOL(mktime64); 385 386 /** 387 * ns_to_timespec - Convert nanoseconds to timespec 388 * @nsec: the nanoseconds value to be converted 389 * 390 * Returns the timespec representation of the nsec parameter. 391 */ 392 struct timespec ns_to_timespec(const s64 nsec) 393 { 394 struct timespec ts; 395 s32 rem; 396 397 if (!nsec) 398 return (struct timespec) {0, 0}; 399 400 ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); 401 if (unlikely(rem < 0)) { 402 ts.tv_sec--; 403 rem += NSEC_PER_SEC; 404 } 405 ts.tv_nsec = rem; 406 407 return ts; 408 } 409 EXPORT_SYMBOL(ns_to_timespec); 410 411 /** 412 * ns_to_timeval - Convert nanoseconds to timeval 413 * @nsec: the nanoseconds value to be converted 414 * 415 * Returns the timeval representation of the nsec parameter. 416 */ 417 struct timeval ns_to_timeval(const s64 nsec) 418 { 419 struct timespec ts = ns_to_timespec(nsec); 420 struct timeval tv; 421 422 tv.tv_sec = ts.tv_sec; 423 tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000; 424 425 return tv; 426 } 427 EXPORT_SYMBOL(ns_to_timeval); 428 429 struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec) 430 { 431 struct timespec64 ts = ns_to_timespec64(nsec); 432 struct __kernel_old_timeval tv; 433 434 tv.tv_sec = ts.tv_sec; 435 tv.tv_usec = (suseconds_t)ts.tv_nsec / 1000; 436 437 return tv; 438 } 439 EXPORT_SYMBOL(ns_to_kernel_old_timeval); 440 441 /** 442 * set_normalized_timespec - set timespec sec and nsec parts and normalize 443 * 444 * @ts: pointer to timespec variable to be set 445 * @sec: seconds to set 446 * @nsec: nanoseconds to set 447 * 448 * Set seconds and nanoseconds field of a timespec variable and 449 * normalize to the timespec storage format 450 * 451 * Note: The tv_nsec part is always in the range of 452 * 0 <= tv_nsec < NSEC_PER_SEC 453 * For negative values only the tv_sec field is negative ! 454 */ 455 void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec) 456 { 457 while (nsec >= NSEC_PER_SEC) { 458 /* 459 * The following asm() prevents the compiler from 460 * optimising this loop into a modulo operation. See 461 * also __iter_div_u64_rem() in include/linux/time.h 462 */ 463 asm("" : "+rm"(nsec)); 464 nsec -= NSEC_PER_SEC; 465 ++sec; 466 } 467 while (nsec < 0) { 468 asm("" : "+rm"(nsec)); 469 nsec += NSEC_PER_SEC; 470 --sec; 471 } 472 ts->tv_sec = sec; 473 ts->tv_nsec = nsec; 474 } 475 EXPORT_SYMBOL(set_normalized_timespec64); 476 477 /** 478 * ns_to_timespec64 - Convert nanoseconds to timespec64 479 * @nsec: the nanoseconds value to be converted 480 * 481 * Returns the timespec64 representation of the nsec parameter. 482 */ 483 struct timespec64 ns_to_timespec64(const s64 nsec) 484 { 485 struct timespec64 ts; 486 s32 rem; 487 488 if (!nsec) 489 return (struct timespec64) {0, 0}; 490 491 ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); 492 if (unlikely(rem < 0)) { 493 ts.tv_sec--; 494 rem += NSEC_PER_SEC; 495 } 496 ts.tv_nsec = rem; 497 498 return ts; 499 } 500 EXPORT_SYMBOL(ns_to_timespec64); 501 502 /** 503 * msecs_to_jiffies: - convert milliseconds to jiffies 504 * @m: time in milliseconds 505 * 506 * conversion is done as follows: 507 * 508 * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) 509 * 510 * - 'too large' values [that would result in larger than 511 * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. 512 * 513 * - all other values are converted to jiffies by either multiplying 514 * the input value by a factor or dividing it with a factor and 515 * handling any 32-bit overflows. 516 * for the details see __msecs_to_jiffies() 517 * 518 * msecs_to_jiffies() checks for the passed in value being a constant 519 * via __builtin_constant_p() allowing gcc to eliminate most of the 520 * code, __msecs_to_jiffies() is called if the value passed does not 521 * allow constant folding and the actual conversion must be done at 522 * runtime. 523 * the _msecs_to_jiffies helpers are the HZ dependent conversion 524 * routines found in include/linux/jiffies.h 525 */ 526 unsigned long __msecs_to_jiffies(const unsigned int m) 527 { 528 /* 529 * Negative value, means infinite timeout: 530 */ 531 if ((int)m < 0) 532 return MAX_JIFFY_OFFSET; 533 return _msecs_to_jiffies(m); 534 } 535 EXPORT_SYMBOL(__msecs_to_jiffies); 536 537 unsigned long __usecs_to_jiffies(const unsigned int u) 538 { 539 if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) 540 return MAX_JIFFY_OFFSET; 541 return _usecs_to_jiffies(u); 542 } 543 EXPORT_SYMBOL(__usecs_to_jiffies); 544 545 /* 546 * The TICK_NSEC - 1 rounds up the value to the next resolution. Note 547 * that a remainder subtract here would not do the right thing as the 548 * resolution values don't fall on second boundries. I.e. the line: 549 * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding. 550 * Note that due to the small error in the multiplier here, this 551 * rounding is incorrect for sufficiently large values of tv_nsec, but 552 * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're 553 * OK. 554 * 555 * Rather, we just shift the bits off the right. 556 * 557 * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec 558 * value to a scaled second value. 559 */ 560 static unsigned long 561 __timespec64_to_jiffies(u64 sec, long nsec) 562 { 563 nsec = nsec + TICK_NSEC - 1; 564 565 if (sec >= MAX_SEC_IN_JIFFIES){ 566 sec = MAX_SEC_IN_JIFFIES; 567 nsec = 0; 568 } 569 return ((sec * SEC_CONVERSION) + 570 (((u64)nsec * NSEC_CONVERSION) >> 571 (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; 572 573 } 574 575 static unsigned long 576 __timespec_to_jiffies(unsigned long sec, long nsec) 577 { 578 return __timespec64_to_jiffies((u64)sec, nsec); 579 } 580 581 unsigned long 582 timespec64_to_jiffies(const struct timespec64 *value) 583 { 584 return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec); 585 } 586 EXPORT_SYMBOL(timespec64_to_jiffies); 587 588 void 589 jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value) 590 { 591 /* 592 * Convert jiffies to nanoseconds and separate with 593 * one divide. 594 */ 595 u32 rem; 596 value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, 597 NSEC_PER_SEC, &rem); 598 value->tv_nsec = rem; 599 } 600 EXPORT_SYMBOL(jiffies_to_timespec64); 601 602 /* 603 * We could use a similar algorithm to timespec_to_jiffies (with a 604 * different multiplier for usec instead of nsec). But this has a 605 * problem with rounding: we can't exactly add TICK_NSEC - 1 to the 606 * usec value, since it's not necessarily integral. 607 * 608 * We could instead round in the intermediate scaled representation 609 * (i.e. in units of 1/2^(large scale) jiffies) but that's also 610 * perilous: the scaling introduces a small positive error, which 611 * combined with a division-rounding-upward (i.e. adding 2^(scale) - 1 612 * units to the intermediate before shifting) leads to accidental 613 * overflow and overestimates. 614 * 615 * At the cost of one additional multiplication by a constant, just 616 * use the timespec implementation. 617 */ 618 unsigned long 619 timeval_to_jiffies(const struct timeval *value) 620 { 621 return __timespec_to_jiffies(value->tv_sec, 622 value->tv_usec * NSEC_PER_USEC); 623 } 624 EXPORT_SYMBOL(timeval_to_jiffies); 625 626 void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value) 627 { 628 /* 629 * Convert jiffies to nanoseconds and separate with 630 * one divide. 631 */ 632 u32 rem; 633 634 value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, 635 NSEC_PER_SEC, &rem); 636 value->tv_usec = rem / NSEC_PER_USEC; 637 } 638 EXPORT_SYMBOL(jiffies_to_timeval); 639 640 /* 641 * Convert jiffies/jiffies_64 to clock_t and back. 642 */ 643 clock_t jiffies_to_clock_t(unsigned long x) 644 { 645 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 646 # if HZ < USER_HZ 647 return x * (USER_HZ / HZ); 648 # else 649 return x / (HZ / USER_HZ); 650 # endif 651 #else 652 return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ); 653 #endif 654 } 655 EXPORT_SYMBOL(jiffies_to_clock_t); 656 657 unsigned long clock_t_to_jiffies(unsigned long x) 658 { 659 #if (HZ % USER_HZ)==0 660 if (x >= ~0UL / (HZ / USER_HZ)) 661 return ~0UL; 662 return x * (HZ / USER_HZ); 663 #else 664 /* Don't worry about loss of precision here .. */ 665 if (x >= ~0UL / HZ * USER_HZ) 666 return ~0UL; 667 668 /* .. but do try to contain it here */ 669 return div_u64((u64)x * HZ, USER_HZ); 670 #endif 671 } 672 EXPORT_SYMBOL(clock_t_to_jiffies); 673 674 u64 jiffies_64_to_clock_t(u64 x) 675 { 676 #if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 677 # if HZ < USER_HZ 678 x = div_u64(x * USER_HZ, HZ); 679 # elif HZ > USER_HZ 680 x = div_u64(x, HZ / USER_HZ); 681 # else 682 /* Nothing to do */ 683 # endif 684 #else 685 /* 686 * There are better ways that don't overflow early, 687 * but even this doesn't overflow in hundreds of years 688 * in 64 bits, so.. 689 */ 690 x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ)); 691 #endif 692 return x; 693 } 694 EXPORT_SYMBOL(jiffies_64_to_clock_t); 695 696 u64 nsec_to_clock_t(u64 x) 697 { 698 #if (NSEC_PER_SEC % USER_HZ) == 0 699 return div_u64(x, NSEC_PER_SEC / USER_HZ); 700 #elif (USER_HZ % 512) == 0 701 return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512); 702 #else 703 /* 704 * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024, 705 * overflow after 64.99 years. 706 * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ... 707 */ 708 return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ); 709 #endif 710 } 711 712 u64 jiffies64_to_nsecs(u64 j) 713 { 714 #if !(NSEC_PER_SEC % HZ) 715 return (NSEC_PER_SEC / HZ) * j; 716 # else 717 return div_u64(j * HZ_TO_NSEC_NUM, HZ_TO_NSEC_DEN); 718 #endif 719 } 720 EXPORT_SYMBOL(jiffies64_to_nsecs); 721 722 /** 723 * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 724 * 725 * @n: nsecs in u64 726 * 727 * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. 728 * And this doesn't return MAX_JIFFY_OFFSET since this function is designed 729 * for scheduler, not for use in device drivers to calculate timeout value. 730 * 731 * note: 732 * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) 733 * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years 734 */ 735 u64 nsecs_to_jiffies64(u64 n) 736 { 737 #if (NSEC_PER_SEC % HZ) == 0 738 /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ 739 return div_u64(n, NSEC_PER_SEC / HZ); 740 #elif (HZ % 512) == 0 741 /* overflow after 292 years if HZ = 1024 */ 742 return div_u64(n * HZ / 512, NSEC_PER_SEC / 512); 743 #else 744 /* 745 * Generic case - optimized for cases where HZ is a multiple of 3. 746 * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc. 747 */ 748 return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); 749 #endif 750 } 751 EXPORT_SYMBOL(nsecs_to_jiffies64); 752 753 /** 754 * nsecs_to_jiffies - Convert nsecs in u64 to jiffies 755 * 756 * @n: nsecs in u64 757 * 758 * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. 759 * And this doesn't return MAX_JIFFY_OFFSET since this function is designed 760 * for scheduler, not for use in device drivers to calculate timeout value. 761 * 762 * note: 763 * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) 764 * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years 765 */ 766 unsigned long nsecs_to_jiffies(u64 n) 767 { 768 return (unsigned long)nsecs_to_jiffies64(n); 769 } 770 EXPORT_SYMBOL_GPL(nsecs_to_jiffies); 771 772 /* 773 * Add two timespec64 values and do a safety check for overflow. 774 * It's assumed that both values are valid (>= 0). 775 * And, each timespec64 is in normalized form. 776 */ 777 struct timespec64 timespec64_add_safe(const struct timespec64 lhs, 778 const struct timespec64 rhs) 779 { 780 struct timespec64 res; 781 782 set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec, 783 lhs.tv_nsec + rhs.tv_nsec); 784 785 if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) { 786 res.tv_sec = TIME64_MAX; 787 res.tv_nsec = 0; 788 } 789 790 return res; 791 } 792 793 int get_timespec64(struct timespec64 *ts, 794 const struct __kernel_timespec __user *uts) 795 { 796 struct __kernel_timespec kts; 797 int ret; 798 799 ret = copy_from_user(&kts, uts, sizeof(kts)); 800 if (ret) 801 return -EFAULT; 802 803 ts->tv_sec = kts.tv_sec; 804 805 /* Zero out the padding for 32 bit systems or in compat mode */ 806 if (IS_ENABLED(CONFIG_64BIT_TIME) && in_compat_syscall()) 807 kts.tv_nsec &= 0xFFFFFFFFUL; 808 809 ts->tv_nsec = kts.tv_nsec; 810 811 return 0; 812 } 813 EXPORT_SYMBOL_GPL(get_timespec64); 814 815 int put_timespec64(const struct timespec64 *ts, 816 struct __kernel_timespec __user *uts) 817 { 818 struct __kernel_timespec kts = { 819 .tv_sec = ts->tv_sec, 820 .tv_nsec = ts->tv_nsec 821 }; 822 823 return copy_to_user(uts, &kts, sizeof(kts)) ? -EFAULT : 0; 824 } 825 EXPORT_SYMBOL_GPL(put_timespec64); 826 827 static int __get_old_timespec32(struct timespec64 *ts64, 828 const struct old_timespec32 __user *cts) 829 { 830 struct old_timespec32 ts; 831 int ret; 832 833 ret = copy_from_user(&ts, cts, sizeof(ts)); 834 if (ret) 835 return -EFAULT; 836 837 ts64->tv_sec = ts.tv_sec; 838 ts64->tv_nsec = ts.tv_nsec; 839 840 return 0; 841 } 842 843 static int __put_old_timespec32(const struct timespec64 *ts64, 844 struct old_timespec32 __user *cts) 845 { 846 struct old_timespec32 ts = { 847 .tv_sec = ts64->tv_sec, 848 .tv_nsec = ts64->tv_nsec 849 }; 850 return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0; 851 } 852 853 int get_old_timespec32(struct timespec64 *ts, const void __user *uts) 854 { 855 if (COMPAT_USE_64BIT_TIME) 856 return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; 857 else 858 return __get_old_timespec32(ts, uts); 859 } 860 EXPORT_SYMBOL_GPL(get_old_timespec32); 861 862 int put_old_timespec32(const struct timespec64 *ts, void __user *uts) 863 { 864 if (COMPAT_USE_64BIT_TIME) 865 return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; 866 else 867 return __put_old_timespec32(ts, uts); 868 } 869 EXPORT_SYMBOL_GPL(put_old_timespec32); 870 871 int get_itimerspec64(struct itimerspec64 *it, 872 const struct __kernel_itimerspec __user *uit) 873 { 874 int ret; 875 876 ret = get_timespec64(&it->it_interval, &uit->it_interval); 877 if (ret) 878 return ret; 879 880 ret = get_timespec64(&it->it_value, &uit->it_value); 881 882 return ret; 883 } 884 EXPORT_SYMBOL_GPL(get_itimerspec64); 885 886 int put_itimerspec64(const struct itimerspec64 *it, 887 struct __kernel_itimerspec __user *uit) 888 { 889 int ret; 890 891 ret = put_timespec64(&it->it_interval, &uit->it_interval); 892 if (ret) 893 return ret; 894 895 ret = put_timespec64(&it->it_value, &uit->it_value); 896 897 return ret; 898 } 899 EXPORT_SYMBOL_GPL(put_itimerspec64); 900 901 int get_old_itimerspec32(struct itimerspec64 *its, 902 const struct old_itimerspec32 __user *uits) 903 { 904 905 if (__get_old_timespec32(&its->it_interval, &uits->it_interval) || 906 __get_old_timespec32(&its->it_value, &uits->it_value)) 907 return -EFAULT; 908 return 0; 909 } 910 EXPORT_SYMBOL_GPL(get_old_itimerspec32); 911 912 int put_old_itimerspec32(const struct itimerspec64 *its, 913 struct old_itimerspec32 __user *uits) 914 { 915 if (__put_old_timespec32(&its->it_interval, &uits->it_interval) || 916 __put_old_timespec32(&its->it_value, &uits->it_value)) 917 return -EFAULT; 918 return 0; 919 } 920 EXPORT_SYMBOL_GPL(put_old_itimerspec32); 921