xref: /openbmc/linux/kernel/time/posix-stubs.c (revision b240b419db5d624ce7a5a397d6f62a1a686009ec)
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 #include <linux/compat.h>
21 
22 asmlinkage long sys_ni_posix_timers(void)
23 {
24 	pr_err_once("process %d (%s) attempted a POSIX timer syscall "
25 		    "while CONFIG_POSIX_TIMERS is not set\n",
26 		    current->pid, current->comm);
27 	return -ENOSYS;
28 }
29 
30 #define SYS_NI(name)  SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
31 #define COMPAT_SYS_NI(name)  SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers)
32 
33 SYS_NI(timer_create);
34 SYS_NI(timer_gettime);
35 SYS_NI(timer_getoverrun);
36 SYS_NI(timer_settime);
37 SYS_NI(timer_delete);
38 SYS_NI(clock_adjtime);
39 SYS_NI(getitimer);
40 SYS_NI(setitimer);
41 #ifdef __ARCH_WANT_SYS_ALARM
42 SYS_NI(alarm);
43 #endif
44 
45 /*
46  * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC
47  * as it is easy to remain compatible with little code. CLOCK_BOOTTIME
48  * is also included for convenience as at least systemd uses it.
49  */
50 
51 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
52 		const struct timespec __user *, tp)
53 {
54 	struct timespec64 new_tp;
55 
56 	if (which_clock != CLOCK_REALTIME)
57 		return -EINVAL;
58 	if (get_timespec64(&new_tp, tp))
59 		return -EFAULT;
60 
61 	return do_sys_settimeofday64(&new_tp, NULL);
62 }
63 
64 int do_clock_gettime(clockid_t which_clock, struct timespec64 *tp)
65 {
66 	switch (which_clock) {
67 	case CLOCK_REALTIME:
68 		ktime_get_real_ts64(tp);
69 		break;
70 	case CLOCK_MONOTONIC:
71 		ktime_get_ts64(tp);
72 		break;
73 	case CLOCK_BOOTTIME:
74 		get_monotonic_boottime64(tp);
75 		break;
76 	case CLOCK_MONOTONIC_ACTIVE:
77 		ktime_get_active_ts64(tp);
78 	default:
79 		return -EINVAL;
80 	}
81 
82 	return 0;
83 }
84 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
85 		struct timespec __user *, tp)
86 {
87 	int ret;
88 	struct timespec64 kernel_tp;
89 
90 	ret = do_clock_gettime(which_clock, &kernel_tp);
91 	if (ret)
92 		return ret;
93 
94 	if (put_timespec64(&kernel_tp, tp))
95 		return -EFAULT;
96 	return 0;
97 }
98 
99 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp)
100 {
101 	struct timespec64 rtn_tp = {
102 		.tv_sec = 0,
103 		.tv_nsec = hrtimer_resolution,
104 	};
105 
106 	switch (which_clock) {
107 	case CLOCK_REALTIME:
108 	case CLOCK_MONOTONIC:
109 	case CLOCK_BOOTTIME:
110 		if (put_timespec64(&rtn_tp, tp))
111 			return -EFAULT;
112 		return 0;
113 	default:
114 		return -EINVAL;
115 	}
116 }
117 
118 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
119 		const struct timespec __user *, rqtp,
120 		struct timespec __user *, rmtp)
121 {
122 	struct timespec64 t;
123 
124 	switch (which_clock) {
125 	case CLOCK_REALTIME:
126 	case CLOCK_MONOTONIC:
127 	case CLOCK_BOOTTIME:
128 		break;
129 	default:
130 		return -EINVAL;
131 	}
132 
133 	if (get_timespec64(&t, rqtp))
134 		return -EFAULT;
135 	if (!timespec64_valid(&t))
136 		return -EINVAL;
137 	if (flags & TIMER_ABSTIME)
138 		rmtp = NULL;
139 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
140 	current->restart_block.nanosleep.rmtp = rmtp;
141 	return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
142 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
143 				 which_clock);
144 }
145 
146 #ifdef CONFIG_COMPAT
147 COMPAT_SYS_NI(timer_create);
148 COMPAT_SYS_NI(clock_adjtime);
149 COMPAT_SYS_NI(timer_settime);
150 COMPAT_SYS_NI(timer_gettime);
151 COMPAT_SYS_NI(getitimer);
152 COMPAT_SYS_NI(setitimer);
153 
154 COMPAT_SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
155 		       struct compat_timespec __user *, tp)
156 {
157 	struct timespec64 new_tp;
158 
159 	if (which_clock != CLOCK_REALTIME)
160 		return -EINVAL;
161 	if (compat_get_timespec64(&new_tp, tp))
162 		return -EFAULT;
163 
164 	return do_sys_settimeofday64(&new_tp, NULL);
165 }
166 
167 COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
168 		       struct compat_timespec __user *, tp)
169 {
170 	int ret;
171 	struct timespec64 kernel_tp;
172 
173 	ret = do_clock_gettime(which_clock, &kernel_tp);
174 	if (ret)
175 		return ret;
176 
177 	if (compat_put_timespec64(&kernel_tp, tp))
178 		return -EFAULT;
179 	return 0;
180 }
181 
182 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
183 		       struct compat_timespec __user *, tp)
184 {
185 	struct timespec64 rtn_tp = {
186 		.tv_sec = 0,
187 		.tv_nsec = hrtimer_resolution,
188 	};
189 
190 	switch (which_clock) {
191 	case CLOCK_REALTIME:
192 	case CLOCK_MONOTONIC:
193 	case CLOCK_BOOTTIME:
194 		if (compat_put_timespec64(&rtn_tp, tp))
195 			return -EFAULT;
196 		return 0;
197 	default:
198 		return -EINVAL;
199 	}
200 }
201 
202 COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
203 		       struct compat_timespec __user *, rqtp,
204 		       struct compat_timespec __user *, rmtp)
205 {
206 	struct timespec64 t;
207 
208 	switch (which_clock) {
209 	case CLOCK_REALTIME:
210 	case CLOCK_MONOTONIC:
211 	case CLOCK_BOOTTIME:
212 		break;
213 	default:
214 		return -EINVAL;
215 	}
216 
217 	if (compat_get_timespec64(&t, rqtp))
218 		return -EFAULT;
219 	if (!timespec64_valid(&t))
220 		return -EINVAL;
221 	if (flags & TIMER_ABSTIME)
222 		rmtp = NULL;
223 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
224 	current->restart_block.nanosleep.compat_rmtp = rmtp;
225 	return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
226 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
227 				 which_clock);
228 }
229 #endif
230