linux-imx

// 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, 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)