xref: /linux/kernel/time/posix-stubs.c (revision 0be3ff0c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Dummy stubs used when CONFIG_POSIX_TIMERS=n
4  *
5  * Created by:  Nicolas Pitre, July 2016
6  * Copyright:   (C) 2016 Linaro Limited
7  */
8 
9 #include <linux/linkage.h>
10 #include <linux/kernel.h>
11 #include <linux/sched.h>
12 #include <linux/errno.h>
13 #include <linux/syscalls.h>
14 #include <linux/ktime.h>
15 #include <linux/timekeeping.h>
16 #include <linux/posix-timers.h>
17 #include <linux/time_namespace.h>
18 #include <linux/compat.h>
19 
20 #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
21 /* Architectures may override SYS_NI and COMPAT_SYS_NI */
22 #include <asm/syscall_wrapper.h>
23 #endif
24 
25 asmlinkage long sys_ni_posix_timers(void)
26 {
27 	pr_err_once("process %d (%s) attempted a POSIX timer syscall "
28 		    "while CONFIG_POSIX_TIMERS is not set\n",
29 		    current->pid, current->comm);
30 	return -ENOSYS;
31 }
32 
33 #ifndef SYS_NI
34 #define SYS_NI(name)  SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
35 #endif
36 
37 #ifndef COMPAT_SYS_NI
38 #define COMPAT_SYS_NI(name)  SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers)
39 #endif
40 
41 SYS_NI(timer_create);
42 SYS_NI(timer_gettime);
43 SYS_NI(timer_getoverrun);
44 SYS_NI(timer_settime);
45 SYS_NI(timer_delete);
46 SYS_NI(clock_adjtime);
47 SYS_NI(getitimer);
48 SYS_NI(setitimer);
49 SYS_NI(clock_adjtime32);
50 #ifdef __ARCH_WANT_SYS_ALARM
51 SYS_NI(alarm);
52 #endif
53 
54 /*
55  * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC
56  * as it is easy to remain compatible with little code. CLOCK_BOOTTIME
57  * is also included for convenience as at least systemd uses it.
58  */
59 
60 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
61 		const struct __kernel_timespec __user *, tp)
62 {
63 	struct timespec64 new_tp;
64 
65 	if (which_clock != CLOCK_REALTIME)
66 		return -EINVAL;
67 	if (get_timespec64(&new_tp, tp))
68 		return -EFAULT;
69 
70 	return do_sys_settimeofday64(&new_tp, NULL);
71 }
72 
73 int do_clock_gettime(clockid_t which_clock, struct timespec64 *tp)
74 {
75 	switch (which_clock) {
76 	case CLOCK_REALTIME:
77 		ktime_get_real_ts64(tp);
78 		break;
79 	case CLOCK_MONOTONIC:
80 		ktime_get_ts64(tp);
81 		timens_add_monotonic(tp);
82 		break;
83 	case CLOCK_BOOTTIME:
84 		ktime_get_boottime_ts64(tp);
85 		timens_add_boottime(tp);
86 		break;
87 	default:
88 		return -EINVAL;
89 	}
90 
91 	return 0;
92 }
93 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
94 		struct __kernel_timespec __user *, tp)
95 {
96 	int ret;
97 	struct timespec64 kernel_tp;
98 
99 	ret = do_clock_gettime(which_clock, &kernel_tp);
100 	if (ret)
101 		return ret;
102 
103 	if (put_timespec64(&kernel_tp, tp))
104 		return -EFAULT;
105 	return 0;
106 }
107 
108 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct __kernel_timespec __user *, tp)
109 {
110 	struct timespec64 rtn_tp = {
111 		.tv_sec = 0,
112 		.tv_nsec = hrtimer_resolution,
113 	};
114 
115 	switch (which_clock) {
116 	case CLOCK_REALTIME:
117 	case CLOCK_MONOTONIC:
118 	case CLOCK_BOOTTIME:
119 		if (put_timespec64(&rtn_tp, tp))
120 			return -EFAULT;
121 		return 0;
122 	default:
123 		return -EINVAL;
124 	}
125 }
126 
127 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
128 		const struct __kernel_timespec __user *, rqtp,
129 		struct __kernel_timespec __user *, rmtp)
130 {
131 	struct timespec64 t;
132 	ktime_t texp;
133 
134 	switch (which_clock) {
135 	case CLOCK_REALTIME:
136 	case CLOCK_MONOTONIC:
137 	case CLOCK_BOOTTIME:
138 		break;
139 	default:
140 		return -EINVAL;
141 	}
142 
143 	if (get_timespec64(&t, rqtp))
144 		return -EFAULT;
145 	if (!timespec64_valid(&t))
146 		return -EINVAL;
147 	if (flags & TIMER_ABSTIME)
148 		rmtp = NULL;
149 	current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
150 	current->restart_block.nanosleep.rmtp = rmtp;
151 	texp = timespec64_to_ktime(t);
152 	if (flags & TIMER_ABSTIME)
153 		texp = timens_ktime_to_host(which_clock, texp);
154 	return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
155 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
156 				 which_clock);
157 }
158 
159 #ifdef CONFIG_COMPAT
160 COMPAT_SYS_NI(timer_create);
161 #endif
162 
163 #if defined(CONFIG_COMPAT) || defined(CONFIG_ALPHA)
164 COMPAT_SYS_NI(getitimer);
165 COMPAT_SYS_NI(setitimer);
166 #endif
167 
168 #ifdef CONFIG_COMPAT_32BIT_TIME
169 SYS_NI(timer_settime32);
170 SYS_NI(timer_gettime32);
171 
172 SYSCALL_DEFINE2(clock_settime32, const clockid_t, which_clock,
173 		struct old_timespec32 __user *, tp)
174 {
175 	struct timespec64 new_tp;
176 
177 	if (which_clock != CLOCK_REALTIME)
178 		return -EINVAL;
179 	if (get_old_timespec32(&new_tp, tp))
180 		return -EFAULT;
181 
182 	return do_sys_settimeofday64(&new_tp, NULL);
183 }
184 
185 SYSCALL_DEFINE2(clock_gettime32, clockid_t, which_clock,
186 		struct old_timespec32 __user *, tp)
187 {
188 	int ret;
189 	struct timespec64 kernel_tp;
190 
191 	ret = do_clock_gettime(which_clock, &kernel_tp);
192 	if (ret)
193 		return ret;
194 
195 	if (put_old_timespec32(&kernel_tp, tp))
196 		return -EFAULT;
197 	return 0;
198 }
199 
200 SYSCALL_DEFINE2(clock_getres_time32, clockid_t, which_clock,
201 		struct old_timespec32 __user *, tp)
202 {
203 	struct timespec64 rtn_tp = {
204 		.tv_sec = 0,
205 		.tv_nsec = hrtimer_resolution,
206 	};
207 
208 	switch (which_clock) {
209 	case CLOCK_REALTIME:
210 	case CLOCK_MONOTONIC:
211 	case CLOCK_BOOTTIME:
212 		if (put_old_timespec32(&rtn_tp, tp))
213 			return -EFAULT;
214 		return 0;
215 	default:
216 		return -EINVAL;
217 	}
218 }
219 
220 SYSCALL_DEFINE4(clock_nanosleep_time32, clockid_t, which_clock, int, flags,
221 		struct old_timespec32 __user *, rqtp,
222 		struct old_timespec32 __user *, rmtp)
223 {
224 	struct timespec64 t;
225 	ktime_t texp;
226 
227 	switch (which_clock) {
228 	case CLOCK_REALTIME:
229 	case CLOCK_MONOTONIC:
230 	case CLOCK_BOOTTIME:
231 		break;
232 	default:
233 		return -EINVAL;
234 	}
235 
236 	if (get_old_timespec32(&t, rqtp))
237 		return -EFAULT;
238 	if (!timespec64_valid(&t))
239 		return -EINVAL;
240 	if (flags & TIMER_ABSTIME)
241 		rmtp = NULL;
242 	current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
243 	current->restart_block.nanosleep.compat_rmtp = rmtp;
244 	texp = timespec64_to_ktime(t);
245 	if (flags & TIMER_ABSTIME)
246 		texp = timens_ktime_to_host(which_clock, texp);
247 	return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
248 				 HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
249 				 which_clock);
250 }
251 #endif
252