kernel/time/posix-stubs.c

   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