kernel/time/posix-stubs.c

   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 /*
  21  * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC
  22  * as it is easy to remain compatible with little code. CLOCK_BOOTTIME
  23  * is also included for convenience as at least systemd uses it.
  24  */
  25
  26 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
  27                 const struct __kernel_timespec __user *, tp)
  28 {
  29         struct timespec64 new_tp;
  30
  31         if (which_clock != CLOCK_REALTIME)
  32                 return -EINVAL;
  33         if (get_timespec64(&new_tp, tp))
  34                 return -EFAULT;
  35
  36         return do_sys_settimeofday64(&new_tp, NULL);
  37 }
  38
  39 static int do_clock_gettime(clockid_t which_clock, struct timespec64 *tp)
  40 {
  41         switch (which_clock) {
  42         case CLOCK_REALTIME:
  43                 ktime_get_real_ts64(tp);
  44                 break;
  45         case CLOCK_MONOTONIC:
  46                 ktime_get_ts64(tp);
  47                 timens_add_monotonic(tp);
  48                 break;
  49         case CLOCK_BOOTTIME:
  50                 ktime_get_boottime_ts64(tp);
  51                 timens_add_boottime(tp);
  52                 break;
  53         default:
  54                 return -EINVAL;
  55         }
  56
  57         return 0;
  58 }
  59
  60 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
  61                 struct __kernel_timespec __user *, tp)
  62 {
  63         int ret;
  64         struct timespec64 kernel_tp;
  65
  66         ret = do_clock_gettime(which_clock, &kernel_tp);
  67         if (ret)
  68                 return ret;
  69
  70         if (put_timespec64(&kernel_tp, tp))
  71                 return -EFAULT;
  72         return 0;
  73 }
  74
  75 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct __kernel_timespec __user *, tp)
  76 {
  77         struct timespec64 rtn_tp = {
  78                 .tv_sec = 0,
  79                 .tv_nsec = hrtimer_resolution,
  80         };
  81
  82         switch (which_clock) {
  83         case CLOCK_REALTIME:
  84         case CLOCK_MONOTONIC:
  85         case CLOCK_BOOTTIME:
  86                 if (put_timespec64(&rtn_tp, tp))
  87                         return -EFAULT;
  88                 return 0;
  89         default:
  90                 return -EINVAL;
  91         }
  92 }
  93
  94 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
  95                 const struct __kernel_timespec __user *, rqtp,
  96                 struct __kernel_timespec __user *, rmtp)
  97 {
  98         struct timespec64 t;
  99         ktime_t texp;
 100
 101         switch (which_clock) {
 102         case CLOCK_REALTIME:
 103         case CLOCK_MONOTONIC:
 104         case CLOCK_BOOTTIME:
 105                 break;
 106         default:
 107                 return -EINVAL;
 108         }
 109
 110         if (get_timespec64(&t, rqtp))
 111                 return -EFAULT;
 112         if (!timespec64_valid(&t))
 113                 return -EINVAL;
 114         if (flags & TIMER_ABSTIME)
 115                 rmtp = NULL;
 116         current->restart_block.fn = do_no_restart_syscall;
 117         current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
 118         current->restart_block.nanosleep.rmtp = rmtp;
 119         texp = timespec64_to_ktime(t);
 120         if (flags & TIMER_ABSTIME)
 121                 texp = timens_ktime_to_host(which_clock, texp);
 122         return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
 123                                  HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 124                                  which_clock);
 125 }
 126
 127 #ifdef CONFIG_COMPAT_32BIT_TIME
 128
 129 SYSCALL_DEFINE2(clock_settime32, const clockid_t, which_clock,
 130                 struct old_timespec32 __user *, tp)
 131 {
 132         struct timespec64 new_tp;
 133
 134         if (which_clock != CLOCK_REALTIME)
 135                 return -EINVAL;
 136         if (get_old_timespec32(&new_tp, tp))
 137                 return -EFAULT;
 138
 139         return do_sys_settimeofday64(&new_tp, NULL);
 140 }
 141
 142 SYSCALL_DEFINE2(clock_gettime32, clockid_t, which_clock,
 143                 struct old_timespec32 __user *, tp)
 144 {
 145         int ret;
 146         struct timespec64 kernel_tp;
 147
 148         ret = do_clock_gettime(which_clock, &kernel_tp);
 149         if (ret)
 150                 return ret;
 151
 152         if (put_old_timespec32(&kernel_tp, tp))
 153                 return -EFAULT;
 154         return 0;
 155 }
 156
 157 SYSCALL_DEFINE2(clock_getres_time32, clockid_t, which_clock,
 158                 struct old_timespec32 __user *, tp)
 159 {
 160         struct timespec64 rtn_tp = {
 161                 .tv_sec = 0,
 162                 .tv_nsec = hrtimer_resolution,
 163         };
 164
 165         switch (which_clock) {
 166         case CLOCK_REALTIME:
 167         case CLOCK_MONOTONIC:
 168         case CLOCK_BOOTTIME:
 169                 if (put_old_timespec32(&rtn_tp, tp))
 170                         return -EFAULT;
 171                 return 0;
 172         default:
 173                 return -EINVAL;
 174         }
 175 }
 176
 177 SYSCALL_DEFINE4(clock_nanosleep_time32, clockid_t, which_clock, int, flags,
 178                 struct old_timespec32 __user *, rqtp,
 179                 struct old_timespec32 __user *, rmtp)
 180 {
 181         struct timespec64 t;
 182         ktime_t texp;
 183
 184         switch (which_clock) {
 185         case CLOCK_REALTIME:
 186         case CLOCK_MONOTONIC:
 187         case CLOCK_BOOTTIME:
 188                 break;
 189         default:
 190                 return -EINVAL;
 191         }
 192
 193         if (get_old_timespec32(&t, rqtp))
 194                 return -EFAULT;
 195         if (!timespec64_valid(&t))
 196                 return -EINVAL;
 197         if (flags & TIMER_ABSTIME)
 198                 rmtp = NULL;
 199         current->restart_block.fn = do_no_restart_syscall;
 200         current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 201         current->restart_block.nanosleep.compat_rmtp = rmtp;
 202         texp = timespec64_to_ktime(t);
 203         if (flags & TIMER_ABSTIME)
 204                 texp = timens_ktime_to_host(which_clock, texp);
 205         return hrtimer_nanosleep(texp, flags & TIMER_ABSTIME ?
 206                                  HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 207                                  which_clock);
 208 }
 209 #endif