aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/time/posix-stubs.c
blob: 749b76f2d7574e7b6a9448dcd309cdaeff9df7a1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/*
 * Dummy stubs used when CONFIG_POSIX_TIMERS=n
 *
 * Created by:  Nicolas Pitre, July 2016
 * Copyright:   (C) 2016 Linaro Limited
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/linkage.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/syscalls.h>
#include <linux/ktime.h>
#include <linux/timekeeping.h>
#include <linux/posix-timers.h>
#include <linux/compat.h>

asmlinkage long sys_ni_posix_timers(void)
{
	pr_err_once("process %d (%s) attempted a POSIX timer syscall "
		    "while CONFIG_POSIX_TIMERS is not set\n",
		    current->pid, current->comm);
	return -ENOSYS;
}

#define SYS_NI(name)  SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)

SYS_NI(timer_create);
SYS_NI(timer_gettime);
SYS_NI(timer_getoverrun);
SYS_NI(timer_settime);
SYS_NI(timer_delete);
SYS_NI(clock_adjtime);
SYS_NI(getitimer);
SYS_NI(setitimer);
#ifdef __ARCH_WANT_SYS_ALARM
SYS_NI(alarm);
#endif

/*
 * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC
 * as it is easy to remain compatible with little code. CLOCK_BOOTTIME
 * is also included for convenience as at least systemd uses it.
 */

SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
		const struct timespec __user *, tp)
{
	struct timespec64 new_tp64;
	struct timespec new_tp;

	if (which_clock != CLOCK_REALTIME)
		return -EINVAL;
	if (copy_from_user(&new_tp, tp, sizeof (*tp)))
		return -EFAULT;

	new_tp64 = timespec_to_timespec64(new_tp);
	return do_sys_settimeofday64(&new_tp64, NULL);
}

SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
		struct timespec __user *,tp)
{
	struct timespec64 kernel_tp64;
	struct timespec kernel_tp;

	switch (which_clock) {
	case CLOCK_REALTIME: ktime_get_real_ts64(&kernel_tp64); break;
	case CLOCK_MONOTONIC: ktime_get_ts64(&kernel_tp64); break;
	case CLOCK_BOOTTIME: get_monotonic_boottime64(&kernel_tp64); break;
	default: return -EINVAL;
	}

	kernel_tp = timespec64_to_timespec(kernel_tp64);
	if (copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
		return -EFAULT;
	return 0;
}

SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp)
{
	struct timespec rtn_tp = {
		.tv_sec = 0,
		.tv_nsec = hrtimer_resolution,
	};

	switch (which_clock) {
	case CLOCK_REALTIME:
	case CLOCK_MONOTONIC:
	case CLOCK_BOOTTIME:
		if (copy_to_user(tp, &rtn_tp, sizeof(rtn_tp)))
			return -EFAULT;
		return 0;
	default:
		return -EINVAL;
	}
}

SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
		const struct timespec __user *, rqtp,
		struct timespec __user *, rmtp)
{
	struct timespec64 t64;
	struct timespec t;

	switch (which_clock) {
	case CLOCK_REALTIME:
	case CLOCK_MONOTONIC:
	case CLOCK_BOOTTIME:
		break;
	default:
		return -EINVAL;
	}

	if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
		return -EFAULT;
	t64 = timespec_to_timespec64(t);
	if (!timespec64_valid(&t64))
		return -EINVAL;
	if (flags & TIMER_ABSTIME)
		rmtp = NULL;
	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
	current->restart_block.nanosleep.rmtp = rmtp;
	return hrtimer_nanosleep(&t64, flags & TIMER_ABSTIME ?
				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
				 which_clock);
}

#ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
		       struct compat_timespec __user *, rqtp,
		       struct compat_timespec __user *, rmtp)
{
	struct timespec64 t64;
	struct timespec t;

	switch (which_clock) {
	case CLOCK_REALTIME:
	case CLOCK_MONOTONIC:
	case CLOCK_BOOTTIME:
		break;
	default:
		return -EINVAL;
	}

	if (compat_get_timespec(&t, rqtp))
		return -EFAULT;
	t64 = timespec_to_timespec64(t);
	if (!timespec64_valid(&t64))
		return -EINVAL;
	if (flags & TIMER_ABSTIME)
		rmtp = NULL;
	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
	current->restart_block.nanosleep.compat_rmtp = rmtp;
	return hrtimer_nanosleep(&t64, flags & TIMER_ABSTIME ?
				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
				 which_clock);
}
#endif