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Diffstat (limited to '')
| -rw-r--r-- | kernel/time/time.c | 983 |
1 files changed, 983 insertions, 0 deletions
diff --git a/kernel/time/time.c b/kernel/time/time.c new file mode 100644 index 000000000..f7d4fa5dd --- /dev/null +++ b/kernel/time/time.c @@ -0,0 +1,983 @@ +/* + * linux/kernel/time.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * This file contains the interface functions for the various + * time related system calls: time, stime, gettimeofday, settimeofday, + * adjtime + */ +/* + * Modification history kernel/time.c + * + * 1993-09-02 Philip Gladstone + * Created file with time related functions from sched/core.c and adjtimex() + * 1993-10-08 Torsten Duwe + * adjtime interface update and CMOS clock write code + * 1995-08-13 Torsten Duwe + * kernel PLL updated to 1994-12-13 specs (rfc-1589) + * 1999-01-16 Ulrich Windl + * Introduced error checking for many cases in adjtimex(). + * Updated NTP code according to technical memorandum Jan '96 + * "A Kernel Model for Precision Timekeeping" by Dave Mills + * Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10) + * (Even though the technical memorandum forbids it) + * 2004-07-14 Christoph Lameter + * Added getnstimeofday to allow the posix timer functions to return + * with nanosecond accuracy + */ + +#include <linux/export.h> +#include <linux/kernel.h> +#include <linux/timex.h> +#include <linux/capability.h> +#include <linux/timekeeper_internal.h> +#include <linux/errno.h> +#include <linux/syscalls.h> +#include <linux/security.h> +#include <linux/fs.h> +#include <linux/math64.h> +#include <linux/ptrace.h> + +#include <linux/uaccess.h> +#include <linux/compat.h> +#include <asm/unistd.h> + +#include <generated/timeconst.h> +#include "timekeeping.h" + +/* + * The timezone where the local system is located. Used as a default by some + * programs who obtain this value by using gettimeofday. + */ +struct timezone sys_tz; + +EXPORT_SYMBOL(sys_tz); + +#ifdef __ARCH_WANT_SYS_TIME + +/* + * sys_time() can be implemented in user-level using + * sys_gettimeofday(). Is this for backwards compatibility? If so, + * why not move it into the appropriate arch directory (for those + * architectures that need it). + */ +SYSCALL_DEFINE1(time, time_t __user *, tloc) +{ + time_t i = (time_t)ktime_get_real_seconds(); + + if (tloc) { + if (put_user(i,tloc)) + return -EFAULT; + } + force_successful_syscall_return(); + return i; +} + +/* + * sys_stime() can be implemented in user-level using + * sys_settimeofday(). Is this for backwards compatibility? If so, + * why not move it into the appropriate arch directory (for those + * architectures that need it). + */ + +SYSCALL_DEFINE1(stime, time_t __user *, tptr) +{ + struct timespec64 tv; + int err; + + if (get_user(tv.tv_sec, tptr)) + return -EFAULT; + + tv.tv_nsec = 0; + + err = security_settime64(&tv, NULL); + if (err) + return err; + + do_settimeofday64(&tv); + return 0; +} + +#endif /* __ARCH_WANT_SYS_TIME */ + +#ifdef CONFIG_COMPAT +#ifdef __ARCH_WANT_COMPAT_SYS_TIME + +/* compat_time_t is a 32 bit "long" and needs to get converted. */ +COMPAT_SYSCALL_DEFINE1(time, compat_time_t __user *, tloc) +{ + compat_time_t i; + + i = (compat_time_t)ktime_get_real_seconds(); + + if (tloc) { + if (put_user(i,tloc)) + return -EFAULT; + } + force_successful_syscall_return(); + return i; +} + +COMPAT_SYSCALL_DEFINE1(stime, compat_time_t __user *, tptr) +{ + struct timespec64 tv; + int err; + + if (get_user(tv.tv_sec, tptr)) + return -EFAULT; + + tv.tv_nsec = 0; + + err = security_settime64(&tv, NULL); + if (err) + return err; + + do_settimeofday64(&tv); + return 0; +} + +#endif /* __ARCH_WANT_COMPAT_SYS_TIME */ +#endif + +SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv, + struct timezone __user *, tz) +{ + if (likely(tv != NULL)) { + struct timespec64 ts; + + ktime_get_real_ts64(&ts); + if (put_user(ts.tv_sec, &tv->tv_sec) || + put_user(ts.tv_nsec / 1000, &tv->tv_usec)) + return -EFAULT; + } + if (unlikely(tz != NULL)) { + if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) + return -EFAULT; + } + return 0; +} + +/* + * In case for some reason the CMOS clock has not already been running + * in UTC, but in some local time: The first time we set the timezone, + * we will warp the clock so that it is ticking UTC time instead of + * local time. Presumably, if someone is setting the timezone then we + * are running in an environment where the programs understand about + * timezones. This should be done at boot time in the /etc/rc script, + * as soon as possible, so that the clock can be set right. Otherwise, + * various programs will get confused when the clock gets warped. + */ + +int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz) +{ + static int firsttime = 1; + int error = 0; + + if (tv && !timespec64_valid_settod(tv)) + return -EINVAL; + + error = security_settime64(tv, tz); + if (error) + return error; + + if (tz) { + /* Verify we're witin the +-15 hrs range */ + if (tz->tz_minuteswest > 15*60 || tz->tz_minuteswest < -15*60) + return -EINVAL; + + sys_tz = *tz; + update_vsyscall_tz(); + if (firsttime) { + firsttime = 0; + if (!tv) + timekeeping_warp_clock(); + } + } + if (tv) + return do_settimeofday64(tv); + return 0; +} + +SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv, + struct timezone __user *, tz) +{ + struct timespec64 new_ts; + struct timeval user_tv; + struct timezone new_tz; + + if (tv) { + if (copy_from_user(&user_tv, tv, sizeof(*tv))) + return -EFAULT; + + if (!timeval_valid(&user_tv)) + return -EINVAL; + + new_ts.tv_sec = user_tv.tv_sec; + new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; + } + if (tz) { + if (copy_from_user(&new_tz, tz, sizeof(*tz))) + return -EFAULT; + } + + return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); +} + +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE2(gettimeofday, struct compat_timeval __user *, tv, + struct timezone __user *, tz) +{ + if (tv) { + struct timespec64 ts; + + ktime_get_real_ts64(&ts); + if (put_user(ts.tv_sec, &tv->tv_sec) || + put_user(ts.tv_nsec / 1000, &tv->tv_usec)) + return -EFAULT; + } + if (tz) { + if (copy_to_user(tz, &sys_tz, sizeof(sys_tz))) + return -EFAULT; + } + + return 0; +} + +COMPAT_SYSCALL_DEFINE2(settimeofday, struct compat_timeval __user *, tv, + struct timezone __user *, tz) +{ + struct timespec64 new_ts; + struct timeval user_tv; + struct timezone new_tz; + + if (tv) { + if (compat_get_timeval(&user_tv, tv)) + return -EFAULT; + new_ts.tv_sec = user_tv.tv_sec; + new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC; + } + if (tz) { + if (copy_from_user(&new_tz, tz, sizeof(*tz))) + return -EFAULT; + } + + return do_sys_settimeofday64(tv ? &new_ts : NULL, tz ? &new_tz : NULL); +} +#endif + +SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p) +{ + struct timex txc; /* Local copy of parameter */ + int ret; + + /* Copy the user data space into the kernel copy + * structure. But bear in mind that the structures + * may change + */ + if (copy_from_user(&txc, txc_p, sizeof(struct timex))) + return -EFAULT; + ret = do_adjtimex(&txc); + return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret; +} + +#ifdef CONFIG_COMPAT + +COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp) +{ + struct timex txc; + int err, ret; + + err = compat_get_timex(&txc, utp); + if (err) + return err; + + ret = do_adjtimex(&txc); + + err = compat_put_timex(utp, &txc); + if (err) + return err; + + return ret; +} +#endif + +/* + * Convert jiffies to milliseconds and back. + * + * Avoid unnecessary multiplications/divisions in the + * two most common HZ cases: + */ +unsigned int jiffies_to_msecs(const unsigned long j) +{ +#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) + return (MSEC_PER_SEC / HZ) * j; +#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) + return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); +#else +# if BITS_PER_LONG == 32 + return (HZ_TO_MSEC_MUL32 * j + (1ULL << HZ_TO_MSEC_SHR32) - 1) >> + HZ_TO_MSEC_SHR32; +# else + return DIV_ROUND_UP(j * HZ_TO_MSEC_NUM, HZ_TO_MSEC_DEN); +# endif +#endif +} +EXPORT_SYMBOL(jiffies_to_msecs); + +unsigned int jiffies_to_usecs(const unsigned long j) +{ + /* + * Hz usually doesn't go much further MSEC_PER_SEC. + * jiffies_to_usecs() and usecs_to_jiffies() depend on that. + */ + BUILD_BUG_ON(HZ > USEC_PER_SEC); + +#if !(USEC_PER_SEC % HZ) + return (USEC_PER_SEC / HZ) * j; +#else +# if BITS_PER_LONG == 32 + return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; +# else + return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; +# endif +#endif +} +EXPORT_SYMBOL(jiffies_to_usecs); + +/** + * timespec_trunc - Truncate timespec to a granularity + * @t: Timespec + * @gran: Granularity in ns. + * + * Truncate a timespec to a granularity. Always rounds down. gran must + * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns). + */ +struct timespec timespec_trunc(struct timespec t, unsigned gran) +{ + /* Avoid division in the common cases 1 ns and 1 s. */ + if (gran == 1) { + /* nothing */ + } else if (gran == NSEC_PER_SEC) { + t.tv_nsec = 0; + } else if (gran > 1 && gran < NSEC_PER_SEC) { + t.tv_nsec -= t.tv_nsec % gran; + } else { + WARN(1, "illegal file time granularity: %u", gran); + } + return t; +} +EXPORT_SYMBOL(timespec_trunc); + +/* + * mktime64 - Converts date to seconds. + * Converts Gregorian date to seconds since 1970-01-01 00:00:00. + * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 + * => year=1980, mon=12, day=31, hour=23, min=59, sec=59. + * + * [For the Julian calendar (which was used in Russia before 1917, + * Britain & colonies before 1752, anywhere else before 1582, + * and is still in use by some communities) leave out the + * -year/100+year/400 terms, and add 10.] + * + * This algorithm was first published by Gauss (I think). + * + * A leap second can be indicated by calling this function with sec as + * 60 (allowable under ISO 8601). The leap second is treated the same + * as the following second since they don't exist in UNIX time. + * + * An encoding of midnight at the end of the day as 24:00:00 - ie. midnight + * tomorrow - (allowable under ISO 8601) is supported. + */ +time64_t mktime64(const unsigned int year0, const unsigned int mon0, + const unsigned int day, const unsigned int hour, + const unsigned int min, const unsigned int sec) +{ + unsigned int mon = mon0, year = year0; + + /* 1..12 -> 11,12,1..10 */ + if (0 >= (int) (mon -= 2)) { + mon += 12; /* Puts Feb last since it has leap day */ + year -= 1; + } + + return ((((time64_t) + (year/4 - year/100 + year/400 + 367*mon/12 + day) + + year*365 - 719499 + )*24 + hour /* now have hours - midnight tomorrow handled here */ + )*60 + min /* now have minutes */ + )*60 + sec; /* finally seconds */ +} +EXPORT_SYMBOL(mktime64); + +/** + * set_normalized_timespec - set timespec sec and nsec parts and normalize + * + * @ts: pointer to timespec variable to be set + * @sec: seconds to set + * @nsec: nanoseconds to set + * + * Set seconds and nanoseconds field of a timespec variable and + * normalize to the timespec storage format + * + * Note: The tv_nsec part is always in the range of + * 0 <= tv_nsec < NSEC_PER_SEC + * For negative values only the tv_sec field is negative ! + */ +void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec) +{ + while (nsec >= NSEC_PER_SEC) { + /* + * The following asm() prevents the compiler from + * optimising this loop into a modulo operation. See + * also __iter_div_u64_rem() in include/linux/time.h + */ + asm("" : "+rm"(nsec)); + nsec -= NSEC_PER_SEC; + ++sec; + } + while (nsec < 0) { + asm("" : "+rm"(nsec)); + nsec += NSEC_PER_SEC; + --sec; + } + ts->tv_sec = sec; + ts->tv_nsec = nsec; +} +EXPORT_SYMBOL(set_normalized_timespec); + +/** + * ns_to_timespec - Convert nanoseconds to timespec + * @nsec: the nanoseconds value to be converted + * + * Returns the timespec representation of the nsec parameter. + */ +struct timespec ns_to_timespec(const s64 nsec) +{ + struct timespec ts; + s32 rem; + + if (!nsec) + return (struct timespec) {0, 0}; + + ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); + if (unlikely(rem < 0)) { + ts.tv_sec--; + rem += NSEC_PER_SEC; + } + ts.tv_nsec = rem; + + return ts; +} +EXPORT_SYMBOL(ns_to_timespec); + +/** + * ns_to_timeval - Convert nanoseconds to timeval + * @nsec: the nanoseconds value to be converted + * + * Returns the timeval representation of the nsec parameter. + */ +struct timeval ns_to_timeval(const s64 nsec) +{ + struct timespec ts = ns_to_timespec(nsec); + struct timeval tv; + + tv.tv_sec = ts.tv_sec; + tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000; + + return tv; +} +EXPORT_SYMBOL(ns_to_timeval); + +struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec) +{ + struct timespec64 ts = ns_to_timespec64(nsec); + struct __kernel_old_timeval tv; + + tv.tv_sec = ts.tv_sec; + tv.tv_usec = (suseconds_t)ts.tv_nsec / 1000; + + return tv; +} +EXPORT_SYMBOL(ns_to_kernel_old_timeval); + +/** + * set_normalized_timespec - set timespec sec and nsec parts and normalize + * + * @ts: pointer to timespec variable to be set + * @sec: seconds to set + * @nsec: nanoseconds to set + * + * Set seconds and nanoseconds field of a timespec variable and + * normalize to the timespec storage format + * + * Note: The tv_nsec part is always in the range of + * 0 <= tv_nsec < NSEC_PER_SEC + * For negative values only the tv_sec field is negative ! + */ +void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec) +{ + while (nsec >= NSEC_PER_SEC) { + /* + * The following asm() prevents the compiler from + * optimising this loop into a modulo operation. See + * also __iter_div_u64_rem() in include/linux/time.h + */ + asm("" : "+rm"(nsec)); + nsec -= NSEC_PER_SEC; + ++sec; + } + while (nsec < 0) { + asm("" : "+rm"(nsec)); + nsec += NSEC_PER_SEC; + --sec; + } + ts->tv_sec = sec; + ts->tv_nsec = nsec; +} +EXPORT_SYMBOL(set_normalized_timespec64); + +/** + * ns_to_timespec64 - Convert nanoseconds to timespec64 + * @nsec: the nanoseconds value to be converted + * + * Returns the timespec64 representation of the nsec parameter. + */ +struct timespec64 ns_to_timespec64(const s64 nsec) +{ + struct timespec64 ts; + s32 rem; + + if (!nsec) + return (struct timespec64) {0, 0}; + + ts.tv_sec = div_s64_rem(nsec, NSEC_PER_SEC, &rem); + if (unlikely(rem < 0)) { + ts.tv_sec--; + rem += NSEC_PER_SEC; + } + ts.tv_nsec = rem; + + return ts; +} +EXPORT_SYMBOL(ns_to_timespec64); + +/** + * msecs_to_jiffies: - convert milliseconds to jiffies + * @m: time in milliseconds + * + * conversion is done as follows: + * + * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) + * + * - 'too large' values [that would result in larger than + * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. + * + * - all other values are converted to jiffies by either multiplying + * the input value by a factor or dividing it with a factor and + * handling any 32-bit overflows. + * for the details see __msecs_to_jiffies() + * + * msecs_to_jiffies() checks for the passed in value being a constant + * via __builtin_constant_p() allowing gcc to eliminate most of the + * code, __msecs_to_jiffies() is called if the value passed does not + * allow constant folding and the actual conversion must be done at + * runtime. + * the _msecs_to_jiffies helpers are the HZ dependent conversion + * routines found in include/linux/jiffies.h + */ +unsigned long __msecs_to_jiffies(const unsigned int m) +{ + /* + * Negative value, means infinite timeout: + */ + if ((int)m < 0) + return MAX_JIFFY_OFFSET; + return _msecs_to_jiffies(m); +} +EXPORT_SYMBOL(__msecs_to_jiffies); + +unsigned long __usecs_to_jiffies(const unsigned int u) +{ + if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) + return MAX_JIFFY_OFFSET; + return _usecs_to_jiffies(u); +} +EXPORT_SYMBOL(__usecs_to_jiffies); + +/* + * The TICK_NSEC - 1 rounds up the value to the next resolution. Note + * that a remainder subtract here would not do the right thing as the + * resolution values don't fall on second boundries. I.e. the line: + * nsec -= nsec % TICK_NSEC; is NOT a correct resolution rounding. + * Note that due to the small error in the multiplier here, this + * rounding is incorrect for sufficiently large values of tv_nsec, but + * well formed timespecs should have tv_nsec < NSEC_PER_SEC, so we're + * OK. + * + * Rather, we just shift the bits off the right. + * + * The >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC) converts the scaled nsec + * value to a scaled second value. + */ +static unsigned long +__timespec64_to_jiffies(u64 sec, long nsec) +{ + nsec = nsec + TICK_NSEC - 1; + + if (sec >= MAX_SEC_IN_JIFFIES){ + sec = MAX_SEC_IN_JIFFIES; + nsec = 0; + } + return ((sec * SEC_CONVERSION) + + (((u64)nsec * NSEC_CONVERSION) >> + (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; + +} + +static unsigned long +__timespec_to_jiffies(unsigned long sec, long nsec) +{ + return __timespec64_to_jiffies((u64)sec, nsec); +} + +unsigned long +timespec64_to_jiffies(const struct timespec64 *value) +{ + return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec); +} +EXPORT_SYMBOL(timespec64_to_jiffies); + +void +jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value) +{ + /* + * Convert jiffies to nanoseconds and separate with + * one divide. + */ + u32 rem; + value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, + NSEC_PER_SEC, &rem); + value->tv_nsec = rem; +} +EXPORT_SYMBOL(jiffies_to_timespec64); + +/* + * We could use a similar algorithm to timespec_to_jiffies (with a + * different multiplier for usec instead of nsec). But this has a + * problem with rounding: we can't exactly add TICK_NSEC - 1 to the + * usec value, since it's not necessarily integral. + * + * We could instead round in the intermediate scaled representation + * (i.e. in units of 1/2^(large scale) jiffies) but that's also + * perilous: the scaling introduces a small positive error, which + * combined with a division-rounding-upward (i.e. adding 2^(scale) - 1 + * units to the intermediate before shifting) leads to accidental + * overflow and overestimates. + * + * At the cost of one additional multiplication by a constant, just + * use the timespec implementation. + */ +unsigned long +timeval_to_jiffies(const struct timeval *value) +{ + return __timespec_to_jiffies(value->tv_sec, + value->tv_usec * NSEC_PER_USEC); +} +EXPORT_SYMBOL(timeval_to_jiffies); + +void jiffies_to_timeval(const unsigned long jiffies, struct timeval *value) +{ + /* + * Convert jiffies to nanoseconds and separate with + * one divide. + */ + u32 rem; + + value->tv_sec = div_u64_rem((u64)jiffies * TICK_NSEC, + NSEC_PER_SEC, &rem); + value->tv_usec = rem / NSEC_PER_USEC; +} +EXPORT_SYMBOL(jiffies_to_timeval); + +/* + * Convert jiffies/jiffies_64 to clock_t and back. + */ +clock_t jiffies_to_clock_t(unsigned long x) +{ +#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 +# if HZ < USER_HZ + return x * (USER_HZ / HZ); +# else + return x / (HZ / USER_HZ); +# endif +#else + return div_u64((u64)x * TICK_NSEC, NSEC_PER_SEC / USER_HZ); +#endif +} +EXPORT_SYMBOL(jiffies_to_clock_t); + +unsigned long clock_t_to_jiffies(unsigned long x) +{ +#if (HZ % USER_HZ)==0 + if (x >= ~0UL / (HZ / USER_HZ)) + return ~0UL; + return x * (HZ / USER_HZ); +#else + /* Don't worry about loss of precision here .. */ + if (x >= ~0UL / HZ * USER_HZ) + return ~0UL; + + /* .. but do try to contain it here */ + return div_u64((u64)x * HZ, USER_HZ); +#endif +} +EXPORT_SYMBOL(clock_t_to_jiffies); + +u64 jiffies_64_to_clock_t(u64 x) +{ +#if (TICK_NSEC % (NSEC_PER_SEC / USER_HZ)) == 0 +# if HZ < USER_HZ + x = div_u64(x * USER_HZ, HZ); +# elif HZ > USER_HZ + x = div_u64(x, HZ / USER_HZ); +# else + /* Nothing to do */ +# endif +#else + /* + * There are better ways that don't overflow early, + * but even this doesn't overflow in hundreds of years + * in 64 bits, so.. + */ + x = div_u64(x * TICK_NSEC, (NSEC_PER_SEC / USER_HZ)); +#endif + return x; +} +EXPORT_SYMBOL(jiffies_64_to_clock_t); + +u64 nsec_to_clock_t(u64 x) +{ +#if (NSEC_PER_SEC % USER_HZ) == 0 + return div_u64(x, NSEC_PER_SEC / USER_HZ); +#elif (USER_HZ % 512) == 0 + return div_u64(x * USER_HZ / 512, NSEC_PER_SEC / 512); +#else + /* + * max relative error 5.7e-8 (1.8s per year) for USER_HZ <= 1024, + * overflow after 64.99 years. + * exact for HZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ... + */ + return div_u64(x * 9, (9ull * NSEC_PER_SEC + (USER_HZ / 2)) / USER_HZ); +#endif +} + +u64 jiffies64_to_nsecs(u64 j) +{ +#if !(NSEC_PER_SEC % HZ) + return (NSEC_PER_SEC / HZ) * j; +# else + return div_u64(j * HZ_TO_NSEC_NUM, HZ_TO_NSEC_DEN); +#endif +} +EXPORT_SYMBOL(jiffies64_to_nsecs); + +/** + * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64 + * + * @n: nsecs in u64 + * + * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. + * And this doesn't return MAX_JIFFY_OFFSET since this function is designed + * for scheduler, not for use in device drivers to calculate timeout value. + * + * note: + * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) + * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years + */ +u64 nsecs_to_jiffies64(u64 n) +{ +#if (NSEC_PER_SEC % HZ) == 0 + /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ + return div_u64(n, NSEC_PER_SEC / HZ); +#elif (HZ % 512) == 0 + /* overflow after 292 years if HZ = 1024 */ + return div_u64(n * HZ / 512, NSEC_PER_SEC / 512); +#else + /* + * Generic case - optimized for cases where HZ is a multiple of 3. + * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc. + */ + return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); +#endif +} +EXPORT_SYMBOL(nsecs_to_jiffies64); + +/** + * nsecs_to_jiffies - Convert nsecs in u64 to jiffies + * + * @n: nsecs in u64 + * + * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. + * And this doesn't return MAX_JIFFY_OFFSET since this function is designed + * for scheduler, not for use in device drivers to calculate timeout value. + * + * note: + * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) + * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years + */ +unsigned long nsecs_to_jiffies(u64 n) +{ + return (unsigned long)nsecs_to_jiffies64(n); +} +EXPORT_SYMBOL_GPL(nsecs_to_jiffies); + +/* + * Add two timespec64 values and do a safety check for overflow. + * It's assumed that both values are valid (>= 0). + * And, each timespec64 is in normalized form. + */ +struct timespec64 timespec64_add_safe(const struct timespec64 lhs, + const struct timespec64 rhs) +{ + struct timespec64 res; + + set_normalized_timespec64(&res, (timeu64_t) lhs.tv_sec + rhs.tv_sec, + lhs.tv_nsec + rhs.tv_nsec); + + if (unlikely(res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec)) { + res.tv_sec = TIME64_MAX; + res.tv_nsec = 0; + } + + return res; +} + +int get_timespec64(struct timespec64 *ts, + const struct __kernel_timespec __user *uts) +{ + struct __kernel_timespec kts; + int ret; + + ret = copy_from_user(&kts, uts, sizeof(kts)); + if (ret) + return -EFAULT; + + ts->tv_sec = kts.tv_sec; + + /* Zero out the padding for 32 bit systems or in compat mode */ + if (IS_ENABLED(CONFIG_64BIT_TIME) && (!IS_ENABLED(CONFIG_64BIT) || in_compat_syscall())) + kts.tv_nsec &= 0xFFFFFFFFUL; + + ts->tv_nsec = kts.tv_nsec; + + return 0; +} +EXPORT_SYMBOL_GPL(get_timespec64); + +int put_timespec64(const struct timespec64 *ts, + struct __kernel_timespec __user *uts) +{ + struct __kernel_timespec kts = { + .tv_sec = ts->tv_sec, + .tv_nsec = ts->tv_nsec + }; + + return copy_to_user(uts, &kts, sizeof(kts)) ? -EFAULT : 0; +} +EXPORT_SYMBOL_GPL(put_timespec64); + +int __compat_get_timespec64(struct timespec64 *ts64, + const struct compat_timespec __user *cts) +{ + struct compat_timespec ts; + int ret; + + ret = copy_from_user(&ts, cts, sizeof(ts)); + if (ret) + return -EFAULT; + + ts64->tv_sec = ts.tv_sec; + ts64->tv_nsec = ts.tv_nsec; + + return 0; +} + +int __compat_put_timespec64(const struct timespec64 *ts64, + struct compat_timespec __user *cts) +{ + struct compat_timespec ts = { + .tv_sec = ts64->tv_sec, + .tv_nsec = ts64->tv_nsec + }; + return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0; +} + +int compat_get_timespec64(struct timespec64 *ts, const void __user *uts) +{ + if (COMPAT_USE_64BIT_TIME) + return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0; + else + return __compat_get_timespec64(ts, uts); +} +EXPORT_SYMBOL_GPL(compat_get_timespec64); + +int compat_put_timespec64(const struct timespec64 *ts, void __user *uts) +{ + if (COMPAT_USE_64BIT_TIME) + return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0; + else + return __compat_put_timespec64(ts, uts); +} +EXPORT_SYMBOL_GPL(compat_put_timespec64); + +int get_itimerspec64(struct itimerspec64 *it, + const struct __kernel_itimerspec __user *uit) +{ + int ret; + + ret = get_timespec64(&it->it_interval, &uit->it_interval); + if (ret) + return ret; + + ret = get_timespec64(&it->it_value, &uit->it_value); + + return ret; +} +EXPORT_SYMBOL_GPL(get_itimerspec64); + +int put_itimerspec64(const struct itimerspec64 *it, + struct __kernel_itimerspec __user *uit) +{ + int ret; + + ret = put_timespec64(&it->it_interval, &uit->it_interval); + if (ret) + return ret; + + ret = put_timespec64(&it->it_value, &uit->it_value); + + return ret; +} +EXPORT_SYMBOL_GPL(put_itimerspec64); + +int get_compat_itimerspec64(struct itimerspec64 *its, + const struct compat_itimerspec __user *uits) +{ + + if (__compat_get_timespec64(&its->it_interval, &uits->it_interval) || + __compat_get_timespec64(&its->it_value, &uits->it_value)) + return -EFAULT; + return 0; +} +EXPORT_SYMBOL_GPL(get_compat_itimerspec64); + +int put_compat_itimerspec64(const struct itimerspec64 *its, + struct compat_itimerspec __user *uits) +{ + if (__compat_put_timespec64(&its->it_interval, &uits->it_interval) || + __compat_put_timespec64(&its->it_value, &uits->it_value)) + return -EFAULT; + return 0; +} +EXPORT_SYMBOL_GPL(put_compat_itimerspec64); |