xref: /openbmc/linux/kernel/time/posix-stubs.c (revision 04a7279f)
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 	default:
77 		return -EINVAL;
78 	}
79 
80 	return 0;
81 }
82 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
83 		struct timespec __user *, tp)
84 {
85 	int ret;
86 	struct timespec64 kernel_tp;
87 
88 	ret = do_clock_gettime(which_clock, &kernel_tp);
89 	if (ret)
90 		return ret;
91 
92 	if (put_timespec64(&kernel_tp, tp))
93 		return -EFAULT;
94 	return 0;
95 }
96 
97 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct timespec __user *, tp)
98 {
99 	struct timespec64 rtn_tp = {
100 		.tv_sec = 0,
101 		.tv_nsec = hrtimer_resolution,
102 	};
103 
104 	switch (which_clock) {
105 	case CLOCK_REALTIME:
106 	case CLOCK_MONOTONIC:
107 	case CLOCK_BOOTTIME:
108 		if (put_timespec64(&rtn_tp, tp))
109 			return -EFAULT;
110 		return 0;
111 	default:
112 		return -EINVAL;
113 	}
114 }
115 
116 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
117 		const struct timespec __user *, rqtp,
118 		struct timespec __user *, rmtp)
119 {
120 	struct timespec64 t;
121 
122 	switch (which_clock) {
123 	case CLOCK_REALTIME:
124 	case CLOCK_MONOTONIC:
125 	case CLOCK_BOOTTIME:
126 		break;
127 	default:
128 		return -EINVAL;
129 	}
130 
131 	if (get_timespec64(&t, rqtp))
132 		return -EFAULT;
133 	if (!timespec64_valid(&t))
134 		return -EINVAL;
135 	if (flags & TIMER_ABSTIME)
136 		rmtp = NULL;
137 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
138 	current->restart_block.nanosleep.rmtp = rmtp;
139 	return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
140 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
141 				 which_clock);
142 }
143 
144 #ifdef CONFIG_COMPAT
145 COMPAT_SYS_NI(timer_create);
146 COMPAT_SYS_NI(clock_adjtime);
147 COMPAT_SYS_NI(timer_settime);
148 COMPAT_SYS_NI(timer_gettime);
149 COMPAT_SYS_NI(getitimer);
150 COMPAT_SYS_NI(setitimer);
151 
152 COMPAT_SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
153 		       struct compat_timespec __user *, tp)
154 {
155 	struct timespec64 new_tp;
156 
157 	if (which_clock != CLOCK_REALTIME)
158 		return -EINVAL;
159 	if (compat_get_timespec64(&new_tp, tp))
160 		return -EFAULT;
161 
162 	return do_sys_settimeofday64(&new_tp, NULL);
163 }
164 
165 COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
166 		       struct compat_timespec __user *, tp)
167 {
168 	int ret;
169 	struct timespec64 kernel_tp;
170 
171 	ret = do_clock_gettime(which_clock, &kernel_tp);
172 	if (ret)
173 		return ret;
174 
175 	if (compat_put_timespec64(&kernel_tp, tp))
176 		return -EFAULT;
177 	return 0;
178 }
179 
180 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
181 		       struct compat_timespec __user *, tp)
182 {
183 	struct timespec64 rtn_tp = {
184 		.tv_sec = 0,
185 		.tv_nsec = hrtimer_resolution,
186 	};
187 
188 	switch (which_clock) {
189 	case CLOCK_REALTIME:
190 	case CLOCK_MONOTONIC:
191 	case CLOCK_BOOTTIME:
192 		if (compat_put_timespec64(&rtn_tp, tp))
193 			return -EFAULT;
194 		return 0;
195 	default:
196 		return -EINVAL;
197 	}
198 }
199 
200 COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
201 		       struct compat_timespec __user *, rqtp,
202 		       struct compat_timespec __user *, rmtp)
203 {
204 	struct timespec64 t;
205 
206 	switch (which_clock) {
207 	case CLOCK_REALTIME:
208 	case CLOCK_MONOTONIC:
209 	case CLOCK_BOOTTIME:
210 		break;
211 	default:
212 		return -EINVAL;
213 	}
214 
215 	if (compat_get_timespec64(&t, rqtp))
216 		return -EFAULT;
217 	if (!timespec64_valid(&t))
218 		return -EINVAL;
219 	if (flags & TIMER_ABSTIME)
220 		rmtp = NULL;
221 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
222 	current->restart_block.nanosleep.compat_rmtp = rmtp;
223 	return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
224 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
225 				 which_clock);
226 }
227 #endif
228