// SPDX-License-Identifier: GPL-2.0
/*
* 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:
*
* 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, __kernel_old_time_t __user *, tloc)
{
__kernel_old_time_t i = (__kernel_old_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, __kernel_old_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_32BIT_TIME
#ifdef __ARCH_WANT_SYS_TIME32
/* old_time32_t is a 32 bit "long" and needs to get converted. */
SYSCALL_DEFINE1(time32, old_time32_t __user *, tloc)
{
old_time32_t i;
i = (old_time32_t)ktime_get_real_seconds();
if (tloc) {
if (put_user(i,tloc))
return -EFAULT;
}
force_successful_syscall_return();
return i;
}
SYSCALL_DEFINE1(stime32, old_time32_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_TIME32 */
#endif
SYSCALL_DEFINE2(gettimeofday, struct __kernel_old_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 within 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 __kernel_old_timeval __user *, tv,