1/*
  2 * Dummy stubs used when CONFIG_POSIX_TIMERS=n
  3 *
  4 * Created by:  Nicolas Pitre, July 2016
  5 * Copyright:   (C) 2016 Linaro Limited
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License version 2 as
  9 * published by the Free Software Foundation.
 10 */
 11
 12#include <linux/linkage.h>
 13#include <linux/kernel.h>
 14#include <linux/sched.h>
 15#include <linux/errno.h>
 16#include <linux/syscalls.h>
 17#include <linux/ktime.h>
 18#include <linux/timekeeping.h>
 19#include <linux/posix-timers.h>
 20
 21asmlinkage long sys_ni_posix_timers(void)
 22{
 23	pr_err_once("process %d (%s) attempted a POSIX timer syscall "
 24		    "while CONFIG_POSIX_TIMERS is not set\n",
 25		    current->pid, current->comm);
 26	return -ENOSYS;
 27}
 28
 29#define SYS_NI(name)  SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
 30
 31SYS_NI(timer_create);
 32SYS_NI(timer_gettime);
 33SYS_NI(timer_getoverrun);
 34SYS_NI(timer_settime);
 35SYS_NI(timer_delete);
 36SYS_NI(clock_adjtime);
 37SYS_NI(getitimer);
 38SYS_NI(setitimer);
 39#ifdef __ARCH_WANT_SYS_ALARM
 40SYS_NI(alarm);
 41#endif
 42
 43/*
 44 * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC
 45 * as it is easy to remain compatible with little code. CLOCK_BOOTTIME
 46 * is also included for convenience as at least systemd uses it.
 47 */
 48
 49SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
 50		const struct timespec __user *, tp)
 51{
 52	struct timespec new_tp;
 53
 54	if (which_clock != CLOCK_REALTIME)
 55		return -EINVAL;
 56	if (copy_from_user(&new_tp, tp, sizeof (*tp)))
 57		return -EFAULT;
 58	return do_sys_settimeofday(&new_tp, NULL);
 59}
 60
 61SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
 62		struct timespec __user *,tp)
 63{
 64	struct timespec kernel_tp;
 65
 66	switch (which_clock) {
 67	case CLOCK_REALTIME: ktime_get_real_ts(&kernel_tp); break;
 68	case CLOCK_MONOTONIC: ktime_get_ts(&kernel_tp); break;
 69	case CLOCK_BOOTTIME: get_monotonic_boottime(&kernel_tp); break;
 70	default: return -EINVAL;
 71	}
 72	if (copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
 73		return -EFAULT;
 74	return 0;
 75}
 76
 77SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp)
 78{
 79	struct timespec rtn_tp = {
 80		.tv_sec = 0,
 81		.tv_nsec = hrtimer_resolution,
 82	};
 83
 84	switch (which_clock) {
 85	case CLOCK_REALTIME:
 86	case CLOCK_MONOTONIC:
 87	case CLOCK_BOOTTIME:
 88		if (copy_to_user(tp, &rtn_tp, sizeof(rtn_tp)))
 89			return -EFAULT;
 90		return 0;
 91	default:
 92		return -EINVAL;
 93	}
 94}
 95
 96SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 97		const struct timespec __user *, rqtp,
 98		struct timespec __user *, rmtp)
 99{
100	struct timespec t;
101
102	switch (which_clock) {
103	case CLOCK_REALTIME:
104	case CLOCK_MONOTONIC:
105	case CLOCK_BOOTTIME:
106		if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
107			return -EFAULT;
108		if (!timespec_valid(&t))
109			return -EINVAL;
110		return hrtimer_nanosleep(&t, rmtp, flags & TIMER_ABSTIME ?
111					 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
112					 which_clock);
113	default:
114		return -EINVAL;
115	}
116}
117
118#ifdef CONFIG_COMPAT
119long clock_nanosleep_restart(struct restart_block *restart_block)
120{
121	return hrtimer_nanosleep_restart(restart_block);
122}
123#endif