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 t64;
 121         struct timespec t;
 122
 123         switch (which_clock) {
 124         case CLOCK_REALTIME:
 125         case CLOCK_MONOTONIC:
 126         case CLOCK_BOOTTIME:
 127                 break;
 128         default:
 129                 return -EINVAL;
 130         }
 131
 132         if (copy_from_user(&t, rqtp, sizeof (struct timespec)))
 133                 return -EFAULT;
 134         t64 = timespec_to_timespec64(t);
 135         if (!timespec64_valid(&t64))
 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(&t64, 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 t64;
 207         struct timespec t;
 208
 209         switch (which_clock) {
 210         case CLOCK_REALTIME:
 211         case CLOCK_MONOTONIC:
 212         case CLOCK_BOOTTIME:
 213                 break;
 214         default:
 215                 return -EINVAL;
 216         }
 217
 218         if (compat_get_timespec(&t, rqtp))
 219                 return -EFAULT;
 220         t64 = timespec_to_timespec64(t);
 221         if (!timespec64_valid(&t64))
 222                 return -EINVAL;
 223         if (flags & TIMER_ABSTIME)
 224                 rmtp = NULL;
 225         current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 226         current->restart_block.nanosleep.compat_rmtp = rmtp;
 227         return hrtimer_nanosleep(&t64, flags & TIMER_ABSTIME ?
 228                                  HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 229                                  which_clock);
 230 }
 231 #endif