xref: /openbmc/linux/kernel/time/posix-stubs.c (revision 5ef12cb4a3a78ffb331c03a795a15eea4ae35155)
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 #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
23 /* Architectures may override SYS_NI and COMPAT_SYS_NI */
24 #include <asm/syscall_wrapper.h>
25 #endif
26 
27 asmlinkage long sys_ni_posix_timers(void)
28 {
29 	pr_err_once("process %d (%s) attempted a POSIX timer syscall "
30 		    "while CONFIG_POSIX_TIMERS is not set\n",
31 		    current->pid, current->comm);
32 	return -ENOSYS;
33 }
34 
35 #ifndef SYS_NI
36 #define SYS_NI(name)  SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
37 #endif
38 
39 #ifndef COMPAT_SYS_NI
40 #define COMPAT_SYS_NI(name)  SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers)
41 #endif
42 
43 SYS_NI(timer_create);
44 SYS_NI(timer_gettime);
45 SYS_NI(timer_getoverrun);
46 SYS_NI(timer_settime);
47 SYS_NI(timer_delete);
48 SYS_NI(clock_adjtime);
49 SYS_NI(getitimer);
50 SYS_NI(setitimer);
51 #ifdef __ARCH_WANT_SYS_ALARM
52 SYS_NI(alarm);
53 #endif
54 
55 /*
56  * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC
57  * as it is easy to remain compatible with little code. CLOCK_BOOTTIME
58  * is also included for convenience as at least systemd uses it.
59  */
60 
61 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
62 		const struct timespec __user *, tp)
63 {
64 	struct timespec64 new_tp;
65 
66 	if (which_clock != CLOCK_REALTIME)
67 		return -EINVAL;
68 	if (get_timespec64(&new_tp, tp))
69 		return -EFAULT;
70 
71 	return do_sys_settimeofday64(&new_tp, NULL);
72 }
73 
74 int do_clock_gettime(clockid_t which_clock, struct timespec64 *tp)
75 {
76 	switch (which_clock) {
77 	case CLOCK_REALTIME:
78 		ktime_get_real_ts64(tp);
79 		break;
80 	case CLOCK_MONOTONIC:
81 		ktime_get_ts64(tp);
82 		break;
83 	case CLOCK_BOOTTIME:
84 		get_monotonic_boottime64(tp);
85 		break;
86 	default:
87 		return -EINVAL;
88 	}
89 
90 	return 0;
91 }
92 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
93 		struct timespec __user *, tp)
94 {
95 	int ret;
96 	struct timespec64 kernel_tp;
97 
98 	ret = do_clock_gettime(which_clock, &kernel_tp);
99 	if (ret)
100 		return ret;
101 
102 	if (put_timespec64(&kernel_tp, tp))
103 		return -EFAULT;
104 	return 0;
105 }
106 
107 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp)
108 {
109 	struct timespec64 rtn_tp = {
110 		.tv_sec = 0,
111 		.tv_nsec = hrtimer_resolution,
112 	};
113 
114 	switch (which_clock) {
115 	case CLOCK_REALTIME:
116 	case CLOCK_MONOTONIC:
117 	case CLOCK_BOOTTIME:
118 		if (put_timespec64(&rtn_tp, tp))
119 			return -EFAULT;
120 		return 0;
121 	default:
122 		return -EINVAL;
123 	}
124 }
125 
126 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
127 		const struct timespec __user *, rqtp,
128 		struct timespec __user *, rmtp)
129 {
130 	struct timespec64 t;
131 
132 	switch (which_clock) {
133 	case CLOCK_REALTIME:
134 	case CLOCK_MONOTONIC:
135 	case CLOCK_BOOTTIME:
136 		break;
137 	default:
138 		return -EINVAL;
139 	}
140 
141 	if (get_timespec64(&t, rqtp))
142 		return -EFAULT;
143 	if (!timespec64_valid(&t))
144 		return -EINVAL;
145 	if (flags & TIMER_ABSTIME)
146 		rmtp = NULL;
147 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
148 	current->restart_block.nanosleep.rmtp = rmtp;
149 	return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
150 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
151 				 which_clock);
152 }
153 
154 #ifdef CONFIG_COMPAT
155 COMPAT_SYS_NI(timer_create);
156 COMPAT_SYS_NI(clock_adjtime);
157 COMPAT_SYS_NI(timer_settime);
158 COMPAT_SYS_NI(timer_gettime);
159 COMPAT_SYS_NI(getitimer);
160 COMPAT_SYS_NI(setitimer);
161 
162 COMPAT_SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
163 		       struct compat_timespec __user *, tp)
164 {
165 	struct timespec64 new_tp;
166 
167 	if (which_clock != CLOCK_REALTIME)
168 		return -EINVAL;
169 	if (compat_get_timespec64(&new_tp, tp))
170 		return -EFAULT;
171 
172 	return do_sys_settimeofday64(&new_tp, NULL);
173 }
174 
175 COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
176 		       struct compat_timespec __user *, tp)
177 {
178 	int ret;
179 	struct timespec64 kernel_tp;
180 
181 	ret = do_clock_gettime(which_clock, &kernel_tp);
182 	if (ret)
183 		return ret;
184 
185 	if (compat_put_timespec64(&kernel_tp, tp))
186 		return -EFAULT;
187 	return 0;
188 }
189 
190 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
191 		       struct compat_timespec __user *, tp)
192 {
193 	struct timespec64 rtn_tp = {
194 		.tv_sec = 0,
195 		.tv_nsec = hrtimer_resolution,
196 	};
197 
198 	switch (which_clock) {
199 	case CLOCK_REALTIME:
200 	case CLOCK_MONOTONIC:
201 	case CLOCK_BOOTTIME:
202 		if (compat_put_timespec64(&rtn_tp, tp))
203 			return -EFAULT;
204 		return 0;
205 	default:
206 		return -EINVAL;
207 	}
208 }
209 
210 COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
211 		       struct compat_timespec __user *, rqtp,
212 		       struct compat_timespec __user *, rmtp)
213 {
214 	struct timespec64 t;
215 
216 	switch (which_clock) {
217 	case CLOCK_REALTIME:
218 	case CLOCK_MONOTONIC:
219 	case CLOCK_BOOTTIME:
220 		break;
221 	default:
222 		return -EINVAL;
223 	}
224 
225 	if (compat_get_timespec64(&t, rqtp))
226 		return -EFAULT;
227 	if (!timespec64_valid(&t))
228 		return -EINVAL;
229 	if (flags & TIMER_ABSTIME)
230 		rmtp = NULL;
231 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
232 	current->restart_block.nanosleep.compat_rmtp = rmtp;
233 	return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
234 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
235 				 which_clock);
236 }
237 #endif
238