| 1 | /* $NetBSD: sys_sched.c,v 1.46 2016/07/30 15:38:17 christos Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 2008, 2011 Mindaugas Rasiukevicius <rmind at NetBSD org> |
| 5 | * 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 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND |
| 17 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 20 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 21 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 22 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 23 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 24 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 25 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 26 | * SUCH DAMAGE. |
| 27 | */ |
| 28 | |
| 29 | /* |
| 30 | * System calls relating to the scheduler. |
| 31 | * |
| 32 | * Lock order: |
| 33 | * |
| 34 | * cpu_lock -> |
| 35 | * proc_lock -> |
| 36 | * proc_t::p_lock -> |
| 37 | * lwp_t::lwp_lock |
| 38 | * |
| 39 | * TODO: |
| 40 | * - Handle pthread_setschedprio() as defined by POSIX; |
| 41 | * - Handle sched_yield() case for SCHED_FIFO as defined by POSIX; |
| 42 | */ |
| 43 | |
| 44 | #include <sys/cdefs.h> |
| 45 | __KERNEL_RCSID(0, "$NetBSD: sys_sched.c,v 1.46 2016/07/30 15:38:17 christos Exp $" ); |
| 46 | |
| 47 | #include <sys/param.h> |
| 48 | |
| 49 | #include <sys/cpu.h> |
| 50 | #include <sys/kauth.h> |
| 51 | #include <sys/kmem.h> |
| 52 | #include <sys/lwp.h> |
| 53 | #include <sys/mutex.h> |
| 54 | #include <sys/proc.h> |
| 55 | #include <sys/pset.h> |
| 56 | #include <sys/sched.h> |
| 57 | #include <sys/syscallargs.h> |
| 58 | #include <sys/sysctl.h> |
| 59 | #include <sys/systm.h> |
| 60 | #include <sys/types.h> |
| 61 | #include <sys/unistd.h> |
| 62 | |
| 63 | static struct sysctllog *sched_sysctl_log; |
| 64 | static kauth_listener_t sched_listener; |
| 65 | |
| 66 | /* |
| 67 | * Convert user priority or the in-kernel priority or convert the current |
| 68 | * priority to the appropriate range according to the policy change. |
| 69 | */ |
| 70 | static pri_t |
| 71 | convert_pri(lwp_t *l, int policy, pri_t pri) |
| 72 | { |
| 73 | |
| 74 | /* Convert user priority to the in-kernel */ |
| 75 | if (pri != PRI_NONE) { |
| 76 | /* Only for real-time threads */ |
| 77 | KASSERT(pri >= SCHED_PRI_MIN && pri <= SCHED_PRI_MAX); |
| 78 | KASSERT(policy != SCHED_OTHER); |
| 79 | return PRI_USER_RT + pri; |
| 80 | } |
| 81 | |
| 82 | /* Neither policy, nor priority change */ |
| 83 | if (l->l_class == policy) |
| 84 | return l->l_priority; |
| 85 | |
| 86 | /* Time-sharing -> real-time */ |
| 87 | if (l->l_class == SCHED_OTHER) { |
| 88 | KASSERT(policy == SCHED_FIFO || policy == SCHED_RR); |
| 89 | return PRI_USER_RT; |
| 90 | } |
| 91 | |
| 92 | /* Real-time -> time-sharing */ |
| 93 | if (policy == SCHED_OTHER) { |
| 94 | KASSERT(l->l_class == SCHED_FIFO || l->l_class == SCHED_RR); |
| 95 | /* |
| 96 | * this is a bit arbitrary because the priority is dynamic |
| 97 | * for SCHED_OTHER threads and will likely be changed by |
| 98 | * the scheduler soon anyway. |
| 99 | */ |
| 100 | return l->l_priority - PRI_USER_RT; |
| 101 | } |
| 102 | |
| 103 | /* Real-time -> real-time */ |
| 104 | return l->l_priority; |
| 105 | } |
| 106 | |
| 107 | int |
| 108 | do_sched_setparam(pid_t pid, lwpid_t lid, int policy, |
| 109 | const struct sched_param *params) |
| 110 | { |
| 111 | struct proc *p; |
| 112 | struct lwp *t; |
| 113 | pri_t pri; |
| 114 | u_int lcnt; |
| 115 | int error; |
| 116 | |
| 117 | error = 0; |
| 118 | |
| 119 | pri = params->sched_priority; |
| 120 | |
| 121 | /* If no parameters specified, just return (this should not happen) */ |
| 122 | if (pri == PRI_NONE && policy == SCHED_NONE) |
| 123 | return 0; |
| 124 | |
| 125 | /* Validate scheduling class */ |
| 126 | if (policy != SCHED_NONE && (policy < SCHED_OTHER || policy > SCHED_RR)) |
| 127 | return EINVAL; |
| 128 | |
| 129 | /* Validate priority */ |
| 130 | if (pri != PRI_NONE && (pri < SCHED_PRI_MIN || pri > SCHED_PRI_MAX)) |
| 131 | return EINVAL; |
| 132 | |
| 133 | if (pid != 0) { |
| 134 | /* Find the process */ |
| 135 | mutex_enter(proc_lock); |
| 136 | p = proc_find(pid); |
| 137 | if (p == NULL) { |
| 138 | mutex_exit(proc_lock); |
| 139 | return ESRCH; |
| 140 | } |
| 141 | mutex_enter(p->p_lock); |
| 142 | mutex_exit(proc_lock); |
| 143 | /* Disallow modification of system processes */ |
| 144 | if ((p->p_flag & PK_SYSTEM) != 0) { |
| 145 | mutex_exit(p->p_lock); |
| 146 | return EPERM; |
| 147 | } |
| 148 | } else { |
| 149 | /* Use the calling process */ |
| 150 | p = curlwp->l_proc; |
| 151 | mutex_enter(p->p_lock); |
| 152 | } |
| 153 | |
| 154 | /* Find the LWP(s) */ |
| 155 | lcnt = 0; |
| 156 | LIST_FOREACH(t, &p->p_lwps, l_sibling) { |
| 157 | pri_t kpri; |
| 158 | int lpolicy; |
| 159 | |
| 160 | if (lid && lid != t->l_lid) |
| 161 | continue; |
| 162 | |
| 163 | lcnt++; |
| 164 | lwp_lock(t); |
| 165 | lpolicy = (policy == SCHED_NONE) ? t->l_class : policy; |
| 166 | |
| 167 | /* Disallow setting of priority for SCHED_OTHER threads */ |
| 168 | if (lpolicy == SCHED_OTHER && pri != PRI_NONE) { |
| 169 | lwp_unlock(t); |
| 170 | error = EINVAL; |
| 171 | break; |
| 172 | } |
| 173 | |
| 174 | /* Convert priority, if needed */ |
| 175 | kpri = convert_pri(t, lpolicy, pri); |
| 176 | |
| 177 | /* Check the permission */ |
| 178 | error = kauth_authorize_process(kauth_cred_get(), |
| 179 | KAUTH_PROCESS_SCHEDULER_SETPARAM, p, t, KAUTH_ARG(lpolicy), |
| 180 | KAUTH_ARG(kpri)); |
| 181 | if (error) { |
| 182 | lwp_unlock(t); |
| 183 | break; |
| 184 | } |
| 185 | |
| 186 | /* Set the scheduling class, change the priority */ |
| 187 | t->l_class = lpolicy; |
| 188 | lwp_changepri(t, kpri); |
| 189 | lwp_unlock(t); |
| 190 | } |
| 191 | mutex_exit(p->p_lock); |
| 192 | return (lcnt == 0) ? ESRCH : error; |
| 193 | } |
| 194 | |
| 195 | /* |
| 196 | * Set scheduling parameters. |
| 197 | */ |
| 198 | int |
| 199 | sys__sched_setparam(struct lwp *l, const struct sys__sched_setparam_args *uap, |
| 200 | register_t *retval) |
| 201 | { |
| 202 | /* { |
| 203 | syscallarg(pid_t) pid; |
| 204 | syscallarg(lwpid_t) lid; |
| 205 | syscallarg(int) policy; |
| 206 | syscallarg(const struct sched_param *) params; |
| 207 | } */ |
| 208 | struct sched_param params; |
| 209 | int error; |
| 210 | |
| 211 | /* Get the parameters from the user-space */ |
| 212 | error = copyin(SCARG(uap, params), ¶ms, sizeof(params)); |
| 213 | if (error) |
| 214 | goto out; |
| 215 | |
| 216 | error = do_sched_setparam(SCARG(uap, pid), SCARG(uap, lid), |
| 217 | SCARG(uap, policy), ¶ms); |
| 218 | out: |
| 219 | return error; |
| 220 | } |
| 221 | |
| 222 | /* |
| 223 | * do_sched_getparam: |
| 224 | * |
| 225 | * if lid=0, returns the parameter of the first LWP in the process. |
| 226 | */ |
| 227 | int |
| 228 | do_sched_getparam(pid_t pid, lwpid_t lid, int *policy, |
| 229 | struct sched_param *params) |
| 230 | { |
| 231 | struct sched_param lparams; |
| 232 | struct lwp *t; |
| 233 | int error, lpolicy; |
| 234 | |
| 235 | t = lwp_find2(pid, lid); /* acquire p_lock */ |
| 236 | if (t == NULL) |
| 237 | return ESRCH; |
| 238 | |
| 239 | /* Check the permission */ |
| 240 | error = kauth_authorize_process(kauth_cred_get(), |
| 241 | KAUTH_PROCESS_SCHEDULER_GETPARAM, t->l_proc, NULL, NULL, NULL); |
| 242 | if (error != 0) { |
| 243 | mutex_exit(t->l_proc->p_lock); |
| 244 | return error; |
| 245 | } |
| 246 | |
| 247 | lwp_lock(t); |
| 248 | lparams.sched_priority = t->l_priority; |
| 249 | lpolicy = t->l_class; |
| 250 | lwp_unlock(t); |
| 251 | mutex_exit(t->l_proc->p_lock); |
| 252 | |
| 253 | /* |
| 254 | * convert to the user-visible priority value. |
| 255 | * it's an inversion of convert_pri(). |
| 256 | * |
| 257 | * the SCHED_OTHER case is a bit arbitrary given that |
| 258 | * - we don't allow setting the priority. |
| 259 | * - the priority is dynamic. |
| 260 | */ |
| 261 | switch (lpolicy) { |
| 262 | case SCHED_OTHER: |
| 263 | lparams.sched_priority -= PRI_USER; |
| 264 | break; |
| 265 | case SCHED_RR: |
| 266 | case SCHED_FIFO: |
| 267 | lparams.sched_priority -= PRI_USER_RT; |
| 268 | break; |
| 269 | } |
| 270 | |
| 271 | if (policy != NULL) |
| 272 | *policy = lpolicy; |
| 273 | |
| 274 | if (params != NULL) |
| 275 | *params = lparams; |
| 276 | |
| 277 | return error; |
| 278 | } |
| 279 | |
| 280 | /* |
| 281 | * Get scheduling parameters. |
| 282 | */ |
| 283 | int |
| 284 | sys__sched_getparam(struct lwp *l, const struct sys__sched_getparam_args *uap, |
| 285 | register_t *retval) |
| 286 | { |
| 287 | /* { |
| 288 | syscallarg(pid_t) pid; |
| 289 | syscallarg(lwpid_t) lid; |
| 290 | syscallarg(int *) policy; |
| 291 | syscallarg(struct sched_param *) params; |
| 292 | } */ |
| 293 | struct sched_param params; |
| 294 | int error, policy; |
| 295 | |
| 296 | error = do_sched_getparam(SCARG(uap, pid), SCARG(uap, lid), &policy, |
| 297 | ¶ms); |
| 298 | if (error) |
| 299 | goto out; |
| 300 | |
| 301 | error = copyout(¶ms, SCARG(uap, params), sizeof(params)); |
| 302 | if (error == 0 && SCARG(uap, policy) != NULL) |
| 303 | error = copyout(&policy, SCARG(uap, policy), sizeof(int)); |
| 304 | out: |
| 305 | return error; |
| 306 | } |
| 307 | |
| 308 | /* |
| 309 | * Allocate the CPU set, and get it from userspace. |
| 310 | */ |
| 311 | static int |
| 312 | genkcpuset(kcpuset_t **dset, const cpuset_t *sset, size_t size) |
| 313 | { |
| 314 | kcpuset_t *kset; |
| 315 | int error; |
| 316 | |
| 317 | kcpuset_create(&kset, true); |
| 318 | error = kcpuset_copyin(sset, kset, size); |
| 319 | if (error) { |
| 320 | kcpuset_unuse(kset, NULL); |
| 321 | } else { |
| 322 | *dset = kset; |
| 323 | } |
| 324 | return error; |
| 325 | } |
| 326 | |
| 327 | /* |
| 328 | * Set affinity. |
| 329 | */ |
| 330 | int |
| 331 | sys__sched_setaffinity(struct lwp *l, |
| 332 | const struct sys__sched_setaffinity_args *uap, register_t *retval) |
| 333 | { |
| 334 | /* { |
| 335 | syscallarg(pid_t) pid; |
| 336 | syscallarg(lwpid_t) lid; |
| 337 | syscallarg(size_t) size; |
| 338 | syscallarg(const cpuset_t *) cpuset; |
| 339 | } */ |
| 340 | kcpuset_t *kcset, *kcpulst = NULL; |
| 341 | struct cpu_info *ici, *ci; |
| 342 | struct proc *p; |
| 343 | struct lwp *t; |
| 344 | CPU_INFO_ITERATOR cii; |
| 345 | bool alloff; |
| 346 | lwpid_t lid; |
| 347 | u_int lcnt; |
| 348 | int error; |
| 349 | |
| 350 | error = genkcpuset(&kcset, SCARG(uap, cpuset), SCARG(uap, size)); |
| 351 | if (error) |
| 352 | return error; |
| 353 | |
| 354 | /* |
| 355 | * Traverse _each_ CPU to: |
| 356 | * - Check that CPUs in the mask have no assigned processor set. |
| 357 | * - Check that at least one CPU from the mask is online. |
| 358 | * - Find the first target CPU to migrate. |
| 359 | * |
| 360 | * To avoid the race with CPU online/offline calls and processor sets, |
| 361 | * cpu_lock will be locked for the entire operation. |
| 362 | */ |
| 363 | ci = NULL; |
| 364 | alloff = false; |
| 365 | mutex_enter(&cpu_lock); |
| 366 | for (CPU_INFO_FOREACH(cii, ici)) { |
| 367 | struct schedstate_percpu *ispc; |
| 368 | |
| 369 | if (!kcpuset_isset(kcset, cpu_index(ici))) { |
| 370 | continue; |
| 371 | } |
| 372 | |
| 373 | ispc = &ici->ci_schedstate; |
| 374 | /* Check that CPU is not in the processor-set */ |
| 375 | if (ispc->spc_psid != PS_NONE) { |
| 376 | error = EPERM; |
| 377 | goto out; |
| 378 | } |
| 379 | /* Skip offline CPUs */ |
| 380 | if (ispc->spc_flags & SPCF_OFFLINE) { |
| 381 | alloff = true; |
| 382 | continue; |
| 383 | } |
| 384 | /* Target CPU to migrate */ |
| 385 | if (ci == NULL) { |
| 386 | ci = ici; |
| 387 | } |
| 388 | } |
| 389 | if (ci == NULL) { |
| 390 | if (alloff) { |
| 391 | /* All CPUs in the set are offline */ |
| 392 | error = EPERM; |
| 393 | goto out; |
| 394 | } |
| 395 | /* Empty set */ |
| 396 | kcpuset_unuse(kcset, &kcpulst); |
| 397 | kcset = NULL; |
| 398 | } |
| 399 | |
| 400 | if (SCARG(uap, pid) != 0) { |
| 401 | /* Find the process */ |
| 402 | mutex_enter(proc_lock); |
| 403 | p = proc_find(SCARG(uap, pid)); |
| 404 | if (p == NULL) { |
| 405 | mutex_exit(proc_lock); |
| 406 | error = ESRCH; |
| 407 | goto out; |
| 408 | } |
| 409 | mutex_enter(p->p_lock); |
| 410 | mutex_exit(proc_lock); |
| 411 | /* Disallow modification of system processes. */ |
| 412 | if ((p->p_flag & PK_SYSTEM) != 0) { |
| 413 | mutex_exit(p->p_lock); |
| 414 | error = EPERM; |
| 415 | goto out; |
| 416 | } |
| 417 | } else { |
| 418 | /* Use the calling process */ |
| 419 | p = l->l_proc; |
| 420 | mutex_enter(p->p_lock); |
| 421 | } |
| 422 | |
| 423 | /* |
| 424 | * Check the permission. |
| 425 | */ |
| 426 | error = kauth_authorize_process(l->l_cred, |
| 427 | KAUTH_PROCESS_SCHEDULER_SETAFFINITY, p, NULL, NULL, NULL); |
| 428 | if (error != 0) { |
| 429 | mutex_exit(p->p_lock); |
| 430 | goto out; |
| 431 | } |
| 432 | |
| 433 | /* Iterate through LWP(s). */ |
| 434 | lcnt = 0; |
| 435 | lid = SCARG(uap, lid); |
| 436 | LIST_FOREACH(t, &p->p_lwps, l_sibling) { |
| 437 | if (lid && lid != t->l_lid) { |
| 438 | continue; |
| 439 | } |
| 440 | lwp_lock(t); |
| 441 | /* No affinity for zombie LWPs. */ |
| 442 | if (t->l_stat == LSZOMB) { |
| 443 | lwp_unlock(t); |
| 444 | continue; |
| 445 | } |
| 446 | /* First, release existing affinity, if any. */ |
| 447 | if (t->l_affinity) { |
| 448 | kcpuset_unuse(t->l_affinity, &kcpulst); |
| 449 | } |
| 450 | if (kcset) { |
| 451 | /* |
| 452 | * Hold a reference on affinity mask, assign mask to |
| 453 | * LWP and migrate it to another CPU (unlocks LWP). |
| 454 | */ |
| 455 | kcpuset_use(kcset); |
| 456 | t->l_affinity = kcset; |
| 457 | lwp_migrate(t, ci); |
| 458 | } else { |
| 459 | /* Old affinity mask is released, just clear. */ |
| 460 | t->l_affinity = NULL; |
| 461 | lwp_unlock(t); |
| 462 | } |
| 463 | lcnt++; |
| 464 | } |
| 465 | mutex_exit(p->p_lock); |
| 466 | if (lcnt == 0) { |
| 467 | error = ESRCH; |
| 468 | } |
| 469 | out: |
| 470 | mutex_exit(&cpu_lock); |
| 471 | |
| 472 | /* |
| 473 | * Drop the initial reference (LWPs, if any, have the ownership now), |
| 474 | * and destroy whatever is in the G/C list, if filled. |
| 475 | */ |
| 476 | if (kcset) { |
| 477 | kcpuset_unuse(kcset, &kcpulst); |
| 478 | } |
| 479 | if (kcpulst) { |
| 480 | kcpuset_destroy(kcpulst); |
| 481 | } |
| 482 | return error; |
| 483 | } |
| 484 | |
| 485 | /* |
| 486 | * Get affinity. |
| 487 | */ |
| 488 | int |
| 489 | sys__sched_getaffinity(struct lwp *l, |
| 490 | const struct sys__sched_getaffinity_args *uap, register_t *retval) |
| 491 | { |
| 492 | /* { |
| 493 | syscallarg(pid_t) pid; |
| 494 | syscallarg(lwpid_t) lid; |
| 495 | syscallarg(size_t) size; |
| 496 | syscallarg(cpuset_t *) cpuset; |
| 497 | } */ |
| 498 | struct lwp *t; |
| 499 | kcpuset_t *kcset; |
| 500 | int error; |
| 501 | |
| 502 | error = genkcpuset(&kcset, SCARG(uap, cpuset), SCARG(uap, size)); |
| 503 | if (error) |
| 504 | return error; |
| 505 | |
| 506 | /* Locks the LWP */ |
| 507 | t = lwp_find2(SCARG(uap, pid), SCARG(uap, lid)); |
| 508 | if (t == NULL) { |
| 509 | error = ESRCH; |
| 510 | goto out; |
| 511 | } |
| 512 | /* Check the permission */ |
| 513 | if (kauth_authorize_process(l->l_cred, |
| 514 | KAUTH_PROCESS_SCHEDULER_GETAFFINITY, t->l_proc, NULL, NULL, NULL)) { |
| 515 | mutex_exit(t->l_proc->p_lock); |
| 516 | error = EPERM; |
| 517 | goto out; |
| 518 | } |
| 519 | lwp_lock(t); |
| 520 | if (t->l_affinity) { |
| 521 | kcpuset_copy(kcset, t->l_affinity); |
| 522 | } else { |
| 523 | kcpuset_zero(kcset); |
| 524 | } |
| 525 | lwp_unlock(t); |
| 526 | mutex_exit(t->l_proc->p_lock); |
| 527 | |
| 528 | error = kcpuset_copyout(kcset, SCARG(uap, cpuset), SCARG(uap, size)); |
| 529 | out: |
| 530 | kcpuset_unuse(kcset, NULL); |
| 531 | return error; |
| 532 | } |
| 533 | |
| 534 | /* |
| 535 | * Priority protection for PTHREAD_PRIO_PROTECT. This is a weak |
| 536 | * analogue of priority inheritance: temp raise the priority |
| 537 | * of the caller when accessing a protected resource. |
| 538 | */ |
| 539 | int |
| 540 | sys__sched_protect(struct lwp *l, |
| 541 | const struct sys__sched_protect_args *uap, register_t *retval) |
| 542 | { |
| 543 | /* { |
| 544 | syscallarg(int) priority; |
| 545 | syscallarg(int *) opriority; |
| 546 | } */ |
| 547 | int error; |
| 548 | pri_t pri; |
| 549 | |
| 550 | KASSERT(l->l_inheritedprio == -1); |
| 551 | KASSERT(l->l_auxprio == -1 || l->l_auxprio == l->l_protectprio); |
| 552 | |
| 553 | pri = SCARG(uap, priority); |
| 554 | error = 0; |
| 555 | lwp_lock(l); |
| 556 | if (pri == -1) { |
| 557 | /* back out priority changes */ |
| 558 | switch(l->l_protectdepth) { |
| 559 | case 0: |
| 560 | error = EINVAL; |
| 561 | break; |
| 562 | case 1: |
| 563 | l->l_protectdepth = 0; |
| 564 | l->l_protectprio = -1; |
| 565 | l->l_auxprio = -1; |
| 566 | break; |
| 567 | default: |
| 568 | l->l_protectdepth--; |
| 569 | break; |
| 570 | } |
| 571 | } else if (pri < 0) { |
| 572 | /* Just retrieve the current value, for debugging */ |
| 573 | if (l->l_protectprio == -1) |
| 574 | error = ENOENT; |
| 575 | else |
| 576 | *retval = l->l_protectprio - PRI_USER_RT; |
| 577 | } else if (__predict_false(pri < SCHED_PRI_MIN || |
| 578 | pri > SCHED_PRI_MAX || l->l_priority > pri + PRI_USER_RT)) { |
| 579 | /* must fail if existing priority is higher */ |
| 580 | error = EPERM; |
| 581 | } else { |
| 582 | /* play along but make no changes if not a realtime LWP. */ |
| 583 | l->l_protectdepth++; |
| 584 | pri += PRI_USER_RT; |
| 585 | if (__predict_true(l->l_class != SCHED_OTHER && |
| 586 | pri > l->l_protectprio)) { |
| 587 | l->l_protectprio = pri; |
| 588 | l->l_auxprio = pri; |
| 589 | } |
| 590 | } |
| 591 | lwp_unlock(l); |
| 592 | |
| 593 | return error; |
| 594 | } |
| 595 | |
| 596 | /* |
| 597 | * Yield. |
| 598 | */ |
| 599 | int |
| 600 | sys_sched_yield(struct lwp *l, const void *v, register_t *retval) |
| 601 | { |
| 602 | |
| 603 | yield(); |
| 604 | return 0; |
| 605 | } |
| 606 | |
| 607 | /* |
| 608 | * Sysctl nodes and initialization. |
| 609 | */ |
| 610 | static void |
| 611 | sysctl_sched_setup(struct sysctllog **clog) |
| 612 | { |
| 613 | const struct sysctlnode *node = NULL; |
| 614 | |
| 615 | sysctl_createv(clog, 0, NULL, NULL, |
| 616 | CTLFLAG_PERMANENT|CTLFLAG_IMMEDIATE, |
| 617 | CTLTYPE_INT, "posix_sched" , |
| 618 | SYSCTL_DESCR("Version of IEEE Std 1003.1 and its " |
| 619 | "Process Scheduling option to which the " |
| 620 | "system attempts to conform" ), |
| 621 | NULL, _POSIX_PRIORITY_SCHEDULING, NULL, 0, |
| 622 | CTL_KERN, CTL_CREATE, CTL_EOL); |
| 623 | sysctl_createv(clog, 0, NULL, &node, |
| 624 | CTLFLAG_PERMANENT, |
| 625 | CTLTYPE_NODE, "sched" , |
| 626 | SYSCTL_DESCR("Scheduler options" ), |
| 627 | NULL, 0, NULL, 0, |
| 628 | CTL_KERN, CTL_CREATE, CTL_EOL); |
| 629 | |
| 630 | if (node == NULL) |
| 631 | return; |
| 632 | |
| 633 | sysctl_createv(clog, 0, &node, NULL, |
| 634 | CTLFLAG_PERMANENT | CTLFLAG_IMMEDIATE, |
| 635 | CTLTYPE_INT, "pri_min" , |
| 636 | SYSCTL_DESCR("Minimal POSIX real-time priority" ), |
| 637 | NULL, SCHED_PRI_MIN, NULL, 0, |
| 638 | CTL_CREATE, CTL_EOL); |
| 639 | sysctl_createv(clog, 0, &node, NULL, |
| 640 | CTLFLAG_PERMANENT | CTLFLAG_IMMEDIATE, |
| 641 | CTLTYPE_INT, "pri_max" , |
| 642 | SYSCTL_DESCR("Maximal POSIX real-time priority" ), |
| 643 | NULL, SCHED_PRI_MAX, NULL, 0, |
| 644 | CTL_CREATE, CTL_EOL); |
| 645 | } |
| 646 | |
| 647 | static int |
| 648 | sched_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie, |
| 649 | void *arg0, void *arg1, void *arg2, void *arg3) |
| 650 | { |
| 651 | struct proc *p; |
| 652 | int result; |
| 653 | |
| 654 | result = KAUTH_RESULT_DEFER; |
| 655 | p = arg0; |
| 656 | |
| 657 | switch (action) { |
| 658 | case KAUTH_PROCESS_SCHEDULER_GETPARAM: |
| 659 | if (kauth_cred_uidmatch(cred, p->p_cred)) |
| 660 | result = KAUTH_RESULT_ALLOW; |
| 661 | break; |
| 662 | |
| 663 | case KAUTH_PROCESS_SCHEDULER_SETPARAM: |
| 664 | if (kauth_cred_uidmatch(cred, p->p_cred)) { |
| 665 | struct lwp *l; |
| 666 | int policy; |
| 667 | pri_t priority; |
| 668 | |
| 669 | l = arg1; |
| 670 | policy = (int)(unsigned long)arg2; |
| 671 | priority = (pri_t)(unsigned long)arg3; |
| 672 | |
| 673 | if ((policy == l->l_class || |
| 674 | (policy != SCHED_FIFO && policy != SCHED_RR)) && |
| 675 | priority <= l->l_priority) |
| 676 | result = KAUTH_RESULT_ALLOW; |
| 677 | } |
| 678 | |
| 679 | break; |
| 680 | |
| 681 | case KAUTH_PROCESS_SCHEDULER_GETAFFINITY: |
| 682 | result = KAUTH_RESULT_ALLOW; |
| 683 | break; |
| 684 | |
| 685 | case KAUTH_PROCESS_SCHEDULER_SETAFFINITY: |
| 686 | /* Privileged; we let the secmodel handle this. */ |
| 687 | break; |
| 688 | |
| 689 | default: |
| 690 | break; |
| 691 | } |
| 692 | |
| 693 | return result; |
| 694 | } |
| 695 | |
| 696 | void |
| 697 | sched_init(void) |
| 698 | { |
| 699 | |
| 700 | sysctl_sched_setup(&sched_sysctl_log); |
| 701 | |
| 702 | sched_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS, |
| 703 | sched_listener_cb, NULL); |
| 704 | } |
| 705 | |