| 1 | /* $NetBSD: subr_time.c,v 1.18 2016/04/23 23:08:26 christos Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1982, 1986, 1989, 1993 |
| 5 | * The Regents of the University of California. All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * 3. Neither the name of the University nor the names of its contributors |
| 16 | * may be used to endorse or promote products derived from this software |
| 17 | * without specific prior written permission. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 29 | * SUCH DAMAGE. |
| 30 | * |
| 31 | * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 |
| 32 | * @(#)kern_time.c 8.4 (Berkeley) 5/26/95 |
| 33 | */ |
| 34 | |
| 35 | #include <sys/cdefs.h> |
| 36 | __KERNEL_RCSID(0, "$NetBSD: subr_time.c,v 1.18 2016/04/23 23:08:26 christos Exp $" ); |
| 37 | |
| 38 | #include <sys/param.h> |
| 39 | #include <sys/kernel.h> |
| 40 | #include <sys/proc.h> |
| 41 | #include <sys/kauth.h> |
| 42 | #include <sys/lwp.h> |
| 43 | #include <sys/timex.h> |
| 44 | #include <sys/time.h> |
| 45 | #include <sys/timetc.h> |
| 46 | #include <sys/intr.h> |
| 47 | |
| 48 | #ifdef DEBUG_STICKS |
| 49 | #define DPRINTF(a) uprintf a |
| 50 | #else |
| 51 | #define DPRINTF(a) |
| 52 | #endif |
| 53 | |
| 54 | /* |
| 55 | * Compute number of hz until specified time. Used to compute second |
| 56 | * argument to callout_reset() from an absolute time. |
| 57 | */ |
| 58 | int |
| 59 | tvhzto(const struct timeval *tvp) |
| 60 | { |
| 61 | struct timeval now, tv; |
| 62 | |
| 63 | tv = *tvp; /* Don't modify original tvp. */ |
| 64 | getmicrotime(&now); |
| 65 | timersub(&tv, &now, &tv); |
| 66 | return tvtohz(&tv); |
| 67 | } |
| 68 | |
| 69 | /* |
| 70 | * Compute number of ticks in the specified amount of time. |
| 71 | */ |
| 72 | int |
| 73 | tvtohz(const struct timeval *tv) |
| 74 | { |
| 75 | unsigned long ticks; |
| 76 | long sec, usec; |
| 77 | |
| 78 | /* |
| 79 | * If the number of usecs in the whole seconds part of the time |
| 80 | * difference fits in a long, then the total number of usecs will |
| 81 | * fit in an unsigned long. Compute the total and convert it to |
| 82 | * ticks, rounding up and adding 1 to allow for the current tick |
| 83 | * to expire. Rounding also depends on unsigned long arithmetic |
| 84 | * to avoid overflow. |
| 85 | * |
| 86 | * Otherwise, if the number of ticks in the whole seconds part of |
| 87 | * the time difference fits in a long, then convert the parts to |
| 88 | * ticks separately and add, using similar rounding methods and |
| 89 | * overflow avoidance. This method would work in the previous |
| 90 | * case, but it is slightly slower and assumes that hz is integral. |
| 91 | * |
| 92 | * Otherwise, round the time difference down to the maximum |
| 93 | * representable value. |
| 94 | * |
| 95 | * If ints are 32-bit, then the maximum value for any timeout in |
| 96 | * 10ms ticks is 248 days. |
| 97 | */ |
| 98 | sec = tv->tv_sec; |
| 99 | usec = tv->tv_usec; |
| 100 | |
| 101 | KASSERT(usec >= 0 && usec < 1000000); |
| 102 | |
| 103 | /* catch overflows in conversion time_t->int */ |
| 104 | if (tv->tv_sec > INT_MAX) |
| 105 | return INT_MAX; |
| 106 | if (tv->tv_sec < 0) |
| 107 | return 0; |
| 108 | |
| 109 | if (sec < 0 || (sec == 0 && usec == 0)) { |
| 110 | /* |
| 111 | * Would expire now or in the past. Return 0 ticks. |
| 112 | * This is different from the legacy tvhzto() interface, |
| 113 | * and callers need to check for it. |
| 114 | */ |
| 115 | ticks = 0; |
| 116 | } else if (sec <= (LONG_MAX / 1000000)) |
| 117 | ticks = (((sec * 1000000) + (unsigned long)usec + (tick - 1)) |
| 118 | / tick) + 1; |
| 119 | else if (sec <= (LONG_MAX / hz)) |
| 120 | ticks = (sec * hz) + |
| 121 | (((unsigned long)usec + (tick - 1)) / tick) + 1; |
| 122 | else |
| 123 | ticks = LONG_MAX; |
| 124 | |
| 125 | if (ticks > INT_MAX) |
| 126 | ticks = INT_MAX; |
| 127 | |
| 128 | return ((int)ticks); |
| 129 | } |
| 130 | |
| 131 | int |
| 132 | tshzto(const struct timespec *tsp) |
| 133 | { |
| 134 | struct timespec now, ts; |
| 135 | |
| 136 | ts = *tsp; /* Don't modify original tsp. */ |
| 137 | getnanotime(&now); |
| 138 | timespecsub(&ts, &now, &ts); |
| 139 | return tstohz(&ts); |
| 140 | } |
| 141 | |
| 142 | int |
| 143 | tshztoup(const struct timespec *tsp) |
| 144 | { |
| 145 | struct timespec now, ts; |
| 146 | |
| 147 | ts = *tsp; /* Don't modify original tsp. */ |
| 148 | getnanouptime(&now); |
| 149 | timespecsub(&ts, &now, &ts); |
| 150 | return tstohz(&ts); |
| 151 | } |
| 152 | |
| 153 | /* |
| 154 | * Compute number of ticks in the specified amount of time. |
| 155 | */ |
| 156 | int |
| 157 | tstohz(const struct timespec *ts) |
| 158 | { |
| 159 | struct timeval tv; |
| 160 | |
| 161 | /* |
| 162 | * usec has great enough resolution for hz, so convert to a |
| 163 | * timeval and use tvtohz() above. |
| 164 | */ |
| 165 | TIMESPEC_TO_TIMEVAL(&tv, ts); |
| 166 | return tvtohz(&tv); |
| 167 | } |
| 168 | |
| 169 | /* |
| 170 | * Check that a proposed value to load into the .it_value or |
| 171 | * .it_interval part of an interval timer is acceptable, and |
| 172 | * fix it to have at least minimal value (i.e. if it is less |
| 173 | * than the resolution of the clock, round it up.). We don't |
| 174 | * timeout the 0,0 value because this means to disable the |
| 175 | * timer or the interval. |
| 176 | */ |
| 177 | int |
| 178 | itimerfix(struct timeval *tv) |
| 179 | { |
| 180 | |
| 181 | if (tv->tv_usec < 0 || tv->tv_usec >= 1000000) |
| 182 | return EINVAL; |
| 183 | if (tv->tv_sec < 0) |
| 184 | return ETIMEDOUT; |
| 185 | if (tv->tv_sec == 0 && tv->tv_usec != 0 && tv->tv_usec < tick) |
| 186 | tv->tv_usec = tick; |
| 187 | return 0; |
| 188 | } |
| 189 | |
| 190 | int |
| 191 | itimespecfix(struct timespec *ts) |
| 192 | { |
| 193 | |
| 194 | if (ts->tv_nsec < 0 || ts->tv_nsec >= 1000000000) |
| 195 | return EINVAL; |
| 196 | if (ts->tv_sec < 0) |
| 197 | return ETIMEDOUT; |
| 198 | if (ts->tv_sec == 0 && ts->tv_nsec != 0 && ts->tv_nsec < tick * 1000) |
| 199 | ts->tv_nsec = tick * 1000; |
| 200 | return 0; |
| 201 | } |
| 202 | |
| 203 | int |
| 204 | inittimeleft(struct timespec *ts, struct timespec *sleepts) |
| 205 | { |
| 206 | |
| 207 | if (itimespecfix(ts)) { |
| 208 | return -1; |
| 209 | } |
| 210 | getnanouptime(sleepts); |
| 211 | return 0; |
| 212 | } |
| 213 | |
| 214 | int |
| 215 | gettimeleft(struct timespec *ts, struct timespec *sleepts) |
| 216 | { |
| 217 | struct timespec sleptts; |
| 218 | |
| 219 | /* |
| 220 | * Reduce ts by elapsed time based on monotonic time scale. |
| 221 | */ |
| 222 | getnanouptime(&sleptts); |
| 223 | timespecadd(ts, sleepts, ts); |
| 224 | timespecsub(ts, &sleptts, ts); |
| 225 | *sleepts = sleptts; |
| 226 | |
| 227 | return tstohz(ts); |
| 228 | } |
| 229 | |
| 230 | static void |
| 231 | ticks2ts(uint64_t ticks, struct timespec *ts) |
| 232 | { |
| 233 | ts->tv_sec = ticks / hz; |
| 234 | uint64_t sticks = ticks - ts->tv_sec * hz; |
| 235 | if (sticks > 18446744073709551LL) /* floor(2^64 / 1000) */ |
| 236 | ts->tv_nsec = sticks / hz * 1000000000LL; |
| 237 | else if (sticks > 18446744073709LL) /* floor(2^64 / 1000000) */ |
| 238 | ts->tv_nsec = sticks * 1000LL / hz * 1000000LL; |
| 239 | else |
| 240 | ts->tv_nsec = sticks * 1000000000LL / hz; |
| 241 | DPRINTF(("%s: %ju/%ju -> %ju.%ju\n" , __func__, |
| 242 | (uintmax_t)ticks, (uintmax_t)sticks, |
| 243 | (uintmax_t)ts->tv_sec, (uintmax_t)ts->tv_nsec)); |
| 244 | } |
| 245 | |
| 246 | int |
| 247 | clock_gettime1(clockid_t clock_id, struct timespec *ts) |
| 248 | { |
| 249 | int error; |
| 250 | uint64_t ticks; |
| 251 | struct proc *p; |
| 252 | |
| 253 | #define CPUCLOCK_ID_MASK (~(CLOCK_THREAD_CPUTIME_ID|CLOCK_PROCESS_CPUTIME_ID)) |
| 254 | if (clock_id & CLOCK_PROCESS_CPUTIME_ID) { |
| 255 | pid_t pid = clock_id & CPUCLOCK_ID_MASK; |
| 256 | |
| 257 | mutex_enter(proc_lock); |
| 258 | p = pid == 0 ? curproc : proc_find(pid); |
| 259 | if (p == NULL) { |
| 260 | mutex_exit(proc_lock); |
| 261 | return ESRCH; |
| 262 | } |
| 263 | ticks = p->p_uticks + p->p_sticks + p->p_iticks; |
| 264 | DPRINTF(("%s: u=%ju, s=%ju, i=%ju\n" , __func__, |
| 265 | (uintmax_t)p->p_uticks, (uintmax_t)p->p_sticks, |
| 266 | (uintmax_t)p->p_iticks)); |
| 267 | mutex_exit(proc_lock); |
| 268 | |
| 269 | // XXX: Perhaps create a special kauth type |
| 270 | error = kauth_authorize_process(curlwp->l_cred, |
| 271 | KAUTH_PROCESS_PTRACE, p, |
| 272 | KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL); |
| 273 | if (error) |
| 274 | return error; |
| 275 | } else if (clock_id & CLOCK_THREAD_CPUTIME_ID) { |
| 276 | struct lwp *l; |
| 277 | lwpid_t lid = clock_id & CPUCLOCK_ID_MASK; |
| 278 | p = curproc; |
| 279 | mutex_enter(p->p_lock); |
| 280 | l = lid == 0 ? curlwp : lwp_find(p, lid); |
| 281 | if (l == NULL) { |
| 282 | mutex_exit(p->p_lock); |
| 283 | return ESRCH; |
| 284 | } |
| 285 | ticks = l->l_rticksum + l->l_slpticksum; |
| 286 | DPRINTF(("%s: r=%ju, s=%ju\n" , __func__, |
| 287 | (uintmax_t)l->l_rticksum, (uintmax_t)l->l_slpticksum)); |
| 288 | mutex_exit(p->p_lock); |
| 289 | } else |
| 290 | ticks = (uint64_t)-1; |
| 291 | |
| 292 | if (ticks != (uint64_t)-1) { |
| 293 | ticks2ts(ticks, ts); |
| 294 | return 0; |
| 295 | } |
| 296 | |
| 297 | switch (clock_id) { |
| 298 | case CLOCK_REALTIME: |
| 299 | nanotime(ts); |
| 300 | break; |
| 301 | case CLOCK_MONOTONIC: |
| 302 | nanouptime(ts); |
| 303 | break; |
| 304 | default: |
| 305 | return EINVAL; |
| 306 | } |
| 307 | |
| 308 | return 0; |
| 309 | } |
| 310 | |
| 311 | /* |
| 312 | * Calculate delta and convert from struct timespec to the ticks. |
| 313 | */ |
| 314 | int |
| 315 | ts2timo(clockid_t clock_id, int flags, struct timespec *ts, |
| 316 | int *timo, struct timespec *start) |
| 317 | { |
| 318 | int error; |
| 319 | struct timespec tsd; |
| 320 | |
| 321 | flags &= TIMER_ABSTIME; |
| 322 | if (start == NULL) |
| 323 | start = &tsd; |
| 324 | |
| 325 | if (flags || start != &tsd) |
| 326 | if ((error = clock_gettime1(clock_id, start)) != 0) |
| 327 | return error; |
| 328 | |
| 329 | if (flags) |
| 330 | timespecsub(ts, start, ts); |
| 331 | |
| 332 | if ((error = itimespecfix(ts)) != 0) |
| 333 | return error; |
| 334 | |
| 335 | if (ts->tv_sec == 0 && ts->tv_nsec == 0) |
| 336 | return ETIMEDOUT; |
| 337 | |
| 338 | *timo = tstohz(ts); |
| 339 | KASSERT(*timo > 0); |
| 340 | |
| 341 | return 0; |
| 342 | } |
| 343 | |