xref: /openbmc/linux/kernel/time/posix-stubs.c (revision bb0eb050)
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 
21 asmlinkage 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 
31 SYS_NI(timer_create);
32 SYS_NI(timer_gettime);
33 SYS_NI(timer_getoverrun);
34 SYS_NI(timer_settime);
35 SYS_NI(timer_delete);
36 SYS_NI(clock_adjtime);
37 SYS_NI(getitimer);
38 SYS_NI(setitimer);
39 #ifdef __ARCH_WANT_SYS_ALARM
40 SYS_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 
49 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
50 		const struct timespec __user *, tp)
51 {
52 	struct timespec64 new_tp64;
53 	struct timespec new_tp;
54 
55 	if (which_clock != CLOCK_REALTIME)
56 		return -EINVAL;
57 	if (copy_from_user(&new_tp, tp, sizeof (*tp)))
58 		return -EFAULT;
59 
60 	new_tp64 = timespec_to_timespec64(new_tp);
61 	return do_sys_settimeofday64(&new_tp64, NULL);
62 }
63 
64 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
65 		struct timespec __user *,tp)
66 {
67 	struct timespec64 kernel_tp64;
68 	struct timespec kernel_tp;
69 
70 	switch (which_clock) {
71 	case CLOCK_REALTIME: ktime_get_real_ts64(&kernel_tp64); break;
72 	case CLOCK_MONOTONIC: ktime_get_ts64(&kernel_tp64); break;
73 	case CLOCK_BOOTTIME: get_monotonic_boottime64(&kernel_tp64); break;
74 	default: return -EINVAL;
75 	}
76 
77 	kernel_tp = timespec64_to_timespec(kernel_tp64);
78 	if (copy_to_user(tp, &kernel_tp, sizeof (kernel_tp)))
79 		return -EFAULT;
80 	return 0;
81 }
82 
83 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp)
84 {
85 	struct timespec rtn_tp = {
86 		.tv_sec = 0,
87 		.tv_nsec = hrtimer_resolution,
88 	};
89 
90 	switch (which_clock) {
91 	case CLOCK_REALTIME:
92 	case CLOCK_MONOTONIC:
93 	case CLOCK_BOOTTIME:
94 		if (copy_to_user(tp, &rtn_tp, sizeof(rtn_tp)))
95 			return -EFAULT;
96 		return 0;
97 	default:
98 		return -EINVAL;
99 	}
100 }
101 
102 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
103 		const struct timespec __user *, rqtp,
104 		struct timespec __user *, rmtp)
105 {
106 	struct timespec64 t64;
107 	struct timespec t;
108 
109 	switch (which_clock) {
110 	case CLOCK_REALTIME:
111 	case CLOCK_MONOTONIC:
112 	case CLOCK_BOOTTIME:
113 		if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
114 			return -EFAULT;
115 		t64 = timespec_to_timespec64(t);
116 		if (!timespec64_valid(&t64))
117 			return -EINVAL;
118 		return hrtimer_nanosleep(&t64, rmtp, flags & TIMER_ABSTIME ?
119 					 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
120 					 which_clock);
121 	default:
122 		return -EINVAL;
123 	}
124 }
125 
126 #ifdef CONFIG_COMPAT
127 long clock_nanosleep_restart(struct restart_block *restart_block)
128 {
129 	return hrtimer_nanosleep_restart(restart_block);
130 }
131 #endif
132