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 #ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
  23 /* Architectures may override SYS_NI and COMPAT_SYS_NI */
  24 #include <asm/syscall_wrapper.h>
  25 #endif
  26
  27 asmlinkage long sys_ni_posix_timers(void)
  28 {
  29         pr_err_once("process %d (%s) attempted a POSIX timer syscall "
  30                     "while CONFIG_POSIX_TIMERS is not set\n",
  31                     current->pid, current->comm);
  32         return -ENOSYS;
  33 }
  34
  35 #ifndef SYS_NI
  36 #define SYS_NI(name)  SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
  37 #endif
  38
  39 #ifndef COMPAT_SYS_NI
  40 #define COMPAT_SYS_NI(name)  SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers)
  41 #endif
  42
  43 SYS_NI(timer_create);
  44 SYS_NI(timer_gettime);
  45 SYS_NI(timer_getoverrun);
  46 SYS_NI(timer_settime);
  47 SYS_NI(timer_delete);
  48 SYS_NI(clock_adjtime);
  49 SYS_NI(getitimer);
  50 SYS_NI(setitimer);
  51 #ifdef __ARCH_WANT_SYS_ALARM
  52 SYS_NI(alarm);
  53 #endif
  54
  55 /*
  56  * We preserve minimal support for CLOCK_REALTIME and CLOCK_MONOTONIC
  57  * as it is easy to remain compatible with little code. CLOCK_BOOTTIME
  58  * is also included for convenience as at least systemd uses it.
  59  */
  60
  61 SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
  62                 const struct __kernel_timespec __user *, tp)
  63 {
  64         struct timespec64 new_tp;
  65
  66         if (which_clock != CLOCK_REALTIME)
  67                 return -EINVAL;
  68         if (get_timespec64(&new_tp, tp))
  69                 return -EFAULT;
  70
  71         return do_sys_settimeofday64(&new_tp, NULL);
  72 }
  73
  74 int do_clock_gettime(clockid_t which_clock, struct timespec64 *tp)
  75 {
  76         switch (which_clock) {
  77         case CLOCK_REALTIME:
  78                 ktime_get_real_ts64(tp);
  79                 break;
  80         case CLOCK_MONOTONIC:
  81                 ktime_get_ts64(tp);
  82                 break;
  83         case CLOCK_BOOTTIME:
  84                 ktime_get_boottime_ts64(tp);
  85                 break;
  86         default:
  87                 return -EINVAL;
  88         }
  89
  90         return 0;
  91 }
  92 SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
  93                 struct __kernel_timespec __user *, tp)
  94 {
  95         int ret;
  96         struct timespec64 kernel_tp;
  97
  98         ret = do_clock_gettime(which_clock, &kernel_tp);
  99         if (ret)
 100                 return ret;
 101
 102         if (put_timespec64(&kernel_tp, tp))
 103                 return -EFAULT;
 104         return 0;
 105 }
 106
 107 SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock, struct __kernel_timespec __user *, tp)
 108 {
 109         struct timespec64 rtn_tp = {
 110                 .tv_sec = 0,
 111                 .tv_nsec = hrtimer_resolution,
 112         };
 113
 114         switch (which_clock) {
 115         case CLOCK_REALTIME:
 116         case CLOCK_MONOTONIC:
 117         case CLOCK_BOOTTIME:
 118                 if (put_timespec64(&rtn_tp, tp))
 119                         return -EFAULT;
 120                 return 0;
 121         default:
 122                 return -EINVAL;
 123         }
 124 }
 125
 126 SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 127                 const struct __kernel_timespec __user *, rqtp,
 128                 struct __kernel_timespec __user *, rmtp)
 129 {
 130         struct timespec64 t;
 131
 132         switch (which_clock) {
 133         case CLOCK_REALTIME:
 134         case CLOCK_MONOTONIC:
 135         case CLOCK_BOOTTIME:
 136                 break;
 137         default:
 138                 return -EINVAL;
 139         }
 140
 141         if (get_timespec64(&t, rqtp))
 142                 return -EFAULT;
 143         if (!timespec64_valid(&t))
 144                 return -EINVAL;
 145         if (flags & TIMER_ABSTIME)
 146                 rmtp = NULL;
 147         current->restart_block.nanosleep.type = rmtp ? TT_NATIVE : TT_NONE;
 148         current->restart_block.nanosleep.rmtp = rmtp;
 149         return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
 150                                  HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 151                                  which_clock);
 152 }
 153
 154 #ifdef CONFIG_COMPAT
 155 COMPAT_SYS_NI(timer_create);
 156 COMPAT_SYS_NI(clock_adjtime);
 157 COMPAT_SYS_NI(timer_settime);
 158 COMPAT_SYS_NI(timer_gettime);
 159 COMPAT_SYS_NI(getitimer);
 160 COMPAT_SYS_NI(setitimer);
 161 #endif
 162
 163 #ifdef CONFIG_COMPAT_32BIT_TIME
 164 COMPAT_SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
 165                        struct compat_timespec __user *, tp)
 166 {
 167         struct timespec64 new_tp;
 168
 169         if (which_clock != CLOCK_REALTIME)
 170                 return -EINVAL;
 171         if (compat_get_timespec64(&new_tp, tp))
 172                 return -EFAULT;
 173
 174         return do_sys_settimeofday64(&new_tp, NULL);
 175 }
 176
 177 COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
 178                        struct compat_timespec __user *, tp)
 179 {
 180         int ret;
 181         struct timespec64 kernel_tp;
 182
 183         ret = do_clock_gettime(which_clock, &kernel_tp);
 184         if (ret)
 185                 return ret;
 186
 187         if (compat_put_timespec64(&kernel_tp, tp))
 188                 return -EFAULT;
 189         return 0;
 190 }
 191
 192 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
 193                        struct compat_timespec __user *, tp)
 194 {
 195         struct timespec64 rtn_tp = {
 196                 .tv_sec = 0,
 197                 .tv_nsec = hrtimer_resolution,
 198         };
 199
 200         switch (which_clock) {
 201         case CLOCK_REALTIME:
 202         case CLOCK_MONOTONIC:
 203         case CLOCK_BOOTTIME:
 204                 if (compat_put_timespec64(&rtn_tp, tp))
 205                         return -EFAULT;
 206                 return 0;
 207         default:
 208                 return -EINVAL;
 209         }
 210 }
 211
 212 COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
 213                        struct compat_timespec __user *, rqtp,
 214                        struct compat_timespec __user *, rmtp)
 215 {
 216         struct timespec64 t;
 217
 218         switch (which_clock) {
 219         case CLOCK_REALTIME:
 220         case CLOCK_MONOTONIC:
 221         case CLOCK_BOOTTIME:
 222                 break;
 223         default:
 224                 return -EINVAL;
 225         }
 226
 227         if (compat_get_timespec64(&t, rqtp))
 228                 return -EFAULT;
 229         if (!timespec64_valid(&t))
 230                 return -EINVAL;
 231         if (flags & TIMER_ABSTIME)
 232                 rmtp = NULL;
 233         current->restart_block.nanosleep.type = rmtp ? TT_COMPAT : TT_NONE;
 234         current->restart_block.nanosleep.compat_rmtp = rmtp;
 235         return hrtimer_nanosleep(&t, flags & TIMER_ABSTIME ?
 236                                  HRTIMER_MODE_ABS : HRTIMER_MODE_REL,
 237                                  which_clock);
 238 }
 239 #endif