1 /*- 2 * Implementation of SVID semaphores 3 * 4 * Author: Daniel Boulet 5 * 6 * This software is provided ``AS IS'' without any warranties of any kind. 7 */ 8 /*- 9 * Copyright (c) 2003-2005 McAfee, Inc. 10 * All rights reserved. 11 * 12 * This software was developed for the FreeBSD Project in part by McAfee 13 * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR 14 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research 15 * program. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_sysvipc.h" 43 #include "opt_mac.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/sysproto.h> 48 #include <sys/eventhandler.h> 49 #include <sys/kernel.h> 50 #include <sys/proc.h> 51 #include <sys/lock.h> 52 #include <sys/module.h> 53 #include <sys/mutex.h> 54 #include <sys/sem.h> 55 #include <sys/syscall.h> 56 #include <sys/sysent.h> 57 #include <sys/sysctl.h> 58 #include <sys/malloc.h> 59 #include <sys/jail.h> 60 #include <sys/mac.h> 61 62 static MALLOC_DEFINE(M_SEM, "sem", "SVID compatible semaphores"); 63 64 #ifdef SEM_DEBUG 65 #define DPRINTF(a) printf a 66 #else 67 #define DPRINTF(a) 68 #endif 69 #ifdef MAC_DEBUG 70 #define MPRINTF(a) printf a 71 #else 72 #define MPRINTF(a) 73 #endif 74 75 static void seminit(void); 76 static int sysvsem_modload(struct module *, int, void *); 77 static int semunload(void); 78 static void semexit_myhook(void *arg, struct proc *p); 79 static int sysctl_sema(SYSCTL_HANDLER_ARGS); 80 static int semvalid(int semid, struct semid_kernel *semakptr); 81 82 #ifndef _SYS_SYSPROTO_H_ 83 struct __semctl_args; 84 int __semctl(struct thread *td, struct __semctl_args *uap); 85 struct semget_args; 86 int semget(struct thread *td, struct semget_args *uap); 87 struct semop_args; 88 int semop(struct thread *td, struct semop_args *uap); 89 #endif 90 91 static struct sem_undo *semu_alloc(struct thread *td); 92 static int semundo_adjust(struct thread *td, struct sem_undo **supptr, 93 int semid, int semnum, int adjval); 94 static void semundo_clear(int semid, int semnum); 95 96 /* XXX casting to (sy_call_t *) is bogus, as usual. */ 97 static sy_call_t *semcalls[] = { 98 (sy_call_t *)__semctl, (sy_call_t *)semget, 99 (sy_call_t *)semop 100 }; 101 102 static struct mtx sem_mtx; /* semaphore global lock */ 103 static int semtot = 0; 104 static struct semid_kernel *sema; /* semaphore id pool */ 105 static struct mtx *sema_mtx; /* semaphore id pool mutexes*/ 106 static struct sem *sem; /* semaphore pool */ 107 SLIST_HEAD(, sem_undo) semu_list; /* list of active undo structures */ 108 static int *semu; /* undo structure pool */ 109 static eventhandler_tag semexit_tag; 110 111 #define SEMUNDO_MTX sem_mtx 112 #define SEMUNDO_LOCK() mtx_lock(&SEMUNDO_MTX); 113 #define SEMUNDO_UNLOCK() mtx_unlock(&SEMUNDO_MTX); 114 #define SEMUNDO_LOCKASSERT(how) mtx_assert(&SEMUNDO_MTX, (how)); 115 116 struct sem { 117 u_short semval; /* semaphore value */ 118 pid_t sempid; /* pid of last operation */ 119 u_short semncnt; /* # awaiting semval > cval */ 120 u_short semzcnt; /* # awaiting semval = 0 */ 121 }; 122 123 /* 124 * Undo structure (one per process) 125 */ 126 struct sem_undo { 127 SLIST_ENTRY(sem_undo) un_next; /* ptr to next active undo structure */ 128 struct proc *un_proc; /* owner of this structure */ 129 short un_cnt; /* # of active entries */ 130 struct undo { 131 short un_adjval; /* adjust on exit values */ 132 short un_num; /* semaphore # */ 133 int un_id; /* semid */ 134 } un_ent[1]; /* undo entries */ 135 }; 136 137 /* 138 * Configuration parameters 139 */ 140 #ifndef SEMMNI 141 #define SEMMNI 10 /* # of semaphore identifiers */ 142 #endif 143 #ifndef SEMMNS 144 #define SEMMNS 60 /* # of semaphores in system */ 145 #endif 146 #ifndef SEMUME 147 #define SEMUME 10 /* max # of undo entries per process */ 148 #endif 149 #ifndef SEMMNU 150 #define SEMMNU 30 /* # of undo structures in system */ 151 #endif 152 153 /* shouldn't need tuning */ 154 #ifndef SEMMAP 155 #define SEMMAP 30 /* # of entries in semaphore map */ 156 #endif 157 #ifndef SEMMSL 158 #define SEMMSL SEMMNS /* max # of semaphores per id */ 159 #endif 160 #ifndef SEMOPM 161 #define SEMOPM 100 /* max # of operations per semop call */ 162 #endif 163 164 #define SEMVMX 32767 /* semaphore maximum value */ 165 #define SEMAEM 16384 /* adjust on exit max value */ 166 167 /* 168 * Due to the way semaphore memory is allocated, we have to ensure that 169 * SEMUSZ is properly aligned. 170 */ 171 172 #define SEM_ALIGN(bytes) (((bytes) + (sizeof(long) - 1)) & ~(sizeof(long) - 1)) 173 174 /* actual size of an undo structure */ 175 #define SEMUSZ SEM_ALIGN(offsetof(struct sem_undo, un_ent[SEMUME])) 176 177 /* 178 * Macro to find a particular sem_undo vector 179 */ 180 #define SEMU(ix) \ 181 ((struct sem_undo *)(((intptr_t)semu)+ix * seminfo.semusz)) 182 183 /* 184 * semaphore info struct 185 */ 186 struct seminfo seminfo = { 187 SEMMAP, /* # of entries in semaphore map */ 188 SEMMNI, /* # of semaphore identifiers */ 189 SEMMNS, /* # of semaphores in system */ 190 SEMMNU, /* # of undo structures in system */ 191 SEMMSL, /* max # of semaphores per id */ 192 SEMOPM, /* max # of operations per semop call */ 193 SEMUME, /* max # of undo entries per process */ 194 SEMUSZ, /* size in bytes of undo structure */ 195 SEMVMX, /* semaphore maximum value */ 196 SEMAEM /* adjust on exit max value */ 197 }; 198 199 SYSCTL_DECL(_kern_ipc); 200 SYSCTL_INT(_kern_ipc, OID_AUTO, semmap, CTLFLAG_RW, &seminfo.semmap, 0, 201 "Number of entries in the semaphore map"); 202 SYSCTL_INT(_kern_ipc, OID_AUTO, semmni, CTLFLAG_RDTUN, &seminfo.semmni, 0, 203 "Number of semaphore identifiers"); 204 SYSCTL_INT(_kern_ipc, OID_AUTO, semmns, CTLFLAG_RDTUN, &seminfo.semmns, 0, 205 "Maximum number of semaphores in the system"); 206 SYSCTL_INT(_kern_ipc, OID_AUTO, semmnu, CTLFLAG_RDTUN, &seminfo.semmnu, 0, 207 "Maximum number of undo structures in the system"); 208 SYSCTL_INT(_kern_ipc, OID_AUTO, semmsl, CTLFLAG_RW, &seminfo.semmsl, 0, 209 "Max semaphores per id"); 210 SYSCTL_INT(_kern_ipc, OID_AUTO, semopm, CTLFLAG_RDTUN, &seminfo.semopm, 0, 211 "Max operations per semop call"); 212 SYSCTL_INT(_kern_ipc, OID_AUTO, semume, CTLFLAG_RDTUN, &seminfo.semume, 0, 213 "Max undo entries per process"); 214 SYSCTL_INT(_kern_ipc, OID_AUTO, semusz, CTLFLAG_RDTUN, &seminfo.semusz, 0, 215 "Size in bytes of undo structure"); 216 SYSCTL_INT(_kern_ipc, OID_AUTO, semvmx, CTLFLAG_RW, &seminfo.semvmx, 0, 217 "Semaphore maximum value"); 218 SYSCTL_INT(_kern_ipc, OID_AUTO, semaem, CTLFLAG_RW, &seminfo.semaem, 0, 219 "Adjust on exit max value"); 220 SYSCTL_PROC(_kern_ipc, OID_AUTO, sema, CTLFLAG_RD, 221 NULL, 0, sysctl_sema, "", ""); 222 223 static void 224 seminit(void) 225 { 226 int i; 227 228 TUNABLE_INT_FETCH("kern.ipc.semmap", &seminfo.semmap); 229 TUNABLE_INT_FETCH("kern.ipc.semmni", &seminfo.semmni); 230 TUNABLE_INT_FETCH("kern.ipc.semmns", &seminfo.semmns); 231 TUNABLE_INT_FETCH("kern.ipc.semmnu", &seminfo.semmnu); 232 TUNABLE_INT_FETCH("kern.ipc.semmsl", &seminfo.semmsl); 233 TUNABLE_INT_FETCH("kern.ipc.semopm", &seminfo.semopm); 234 TUNABLE_INT_FETCH("kern.ipc.semume", &seminfo.semume); 235 TUNABLE_INT_FETCH("kern.ipc.semusz", &seminfo.semusz); 236 TUNABLE_INT_FETCH("kern.ipc.semvmx", &seminfo.semvmx); 237 TUNABLE_INT_FETCH("kern.ipc.semaem", &seminfo.semaem); 238 239 sem = malloc(sizeof(struct sem) * seminfo.semmns, M_SEM, M_WAITOK); 240 sema = malloc(sizeof(struct semid_kernel) * seminfo.semmni, M_SEM, 241 M_WAITOK); 242 sema_mtx = malloc(sizeof(struct mtx) * seminfo.semmni, M_SEM, 243 M_WAITOK | M_ZERO); 244 semu = malloc(seminfo.semmnu * seminfo.semusz, M_SEM, M_WAITOK); 245 246 for (i = 0; i < seminfo.semmni; i++) { 247 sema[i].u.sem_base = 0; 248 sema[i].u.sem_perm.mode = 0; 249 sema[i].u.sem_perm.seq = 0; 250 #ifdef MAC 251 mac_init_sysv_sema(&sema[i]); 252 #endif 253 } 254 for (i = 0; i < seminfo.semmni; i++) 255 mtx_init(&sema_mtx[i], "semid", NULL, MTX_DEF); 256 for (i = 0; i < seminfo.semmnu; i++) { 257 struct sem_undo *suptr = SEMU(i); 258 suptr->un_proc = NULL; 259 } 260 SLIST_INIT(&semu_list); 261 mtx_init(&sem_mtx, "sem", NULL, MTX_DEF); 262 semexit_tag = EVENTHANDLER_REGISTER(process_exit, semexit_myhook, NULL, 263 EVENTHANDLER_PRI_ANY); 264 } 265 266 static int 267 semunload(void) 268 { 269 int i; 270 271 if (semtot != 0) 272 return (EBUSY); 273 274 EVENTHANDLER_DEREGISTER(process_exit, semexit_tag); 275 #ifdef MAC 276 for (i = 0; i < seminfo.semmni; i++) 277 mac_destroy_sysv_sema(&sema[i]); 278 #endif 279 free(sem, M_SEM); 280 free(sema, M_SEM); 281 free(semu, M_SEM); 282 for (i = 0; i < seminfo.semmni; i++) 283 mtx_destroy(&sema_mtx[i]); 284 mtx_destroy(&sem_mtx); 285 return (0); 286 } 287 288 static int 289 sysvsem_modload(struct module *module, int cmd, void *arg) 290 { 291 int error = 0; 292 293 switch (cmd) { 294 case MOD_LOAD: 295 seminit(); 296 break; 297 case MOD_UNLOAD: 298 error = semunload(); 299 break; 300 case MOD_SHUTDOWN: 301 break; 302 default: 303 error = EINVAL; 304 break; 305 } 306 return (error); 307 } 308 309 static moduledata_t sysvsem_mod = { 310 "sysvsem", 311 &sysvsem_modload, 312 NULL 313 }; 314 315 SYSCALL_MODULE_HELPER(semsys); 316 SYSCALL_MODULE_HELPER(__semctl); 317 SYSCALL_MODULE_HELPER(semget); 318 SYSCALL_MODULE_HELPER(semop); 319 320 DECLARE_MODULE(sysvsem, sysvsem_mod, 321 SI_SUB_SYSV_SEM, SI_ORDER_FIRST); 322 MODULE_VERSION(sysvsem, 1); 323 324 /* 325 * Entry point for all SEM calls 326 * 327 * MPSAFE 328 */ 329 int 330 semsys(td, uap) 331 struct thread *td; 332 /* XXX actually varargs. */ 333 struct semsys_args /* { 334 int which; 335 int a2; 336 int a3; 337 int a4; 338 int a5; 339 } */ *uap; 340 { 341 int error; 342 343 if (!jail_sysvipc_allowed && jailed(td->td_ucred)) 344 return (ENOSYS); 345 if (uap->which < 0 || 346 uap->which >= sizeof(semcalls)/sizeof(semcalls[0])) 347 return (EINVAL); 348 error = (*semcalls[uap->which])(td, &uap->a2); 349 return (error); 350 } 351 352 /* 353 * Allocate a new sem_undo structure for a process 354 * (returns ptr to structure or NULL if no more room) 355 */ 356 357 static struct sem_undo * 358 semu_alloc(td) 359 struct thread *td; 360 { 361 int i; 362 struct sem_undo *suptr; 363 struct sem_undo **supptr; 364 int attempt; 365 366 SEMUNDO_LOCKASSERT(MA_OWNED); 367 /* 368 * Try twice to allocate something. 369 * (we'll purge an empty structure after the first pass so 370 * two passes are always enough) 371 */ 372 373 for (attempt = 0; attempt < 2; attempt++) { 374 /* 375 * Look for a free structure. 376 * Fill it in and return it if we find one. 377 */ 378 379 for (i = 0; i < seminfo.semmnu; i++) { 380 suptr = SEMU(i); 381 if (suptr->un_proc == NULL) { 382 SLIST_INSERT_HEAD(&semu_list, suptr, un_next); 383 suptr->un_cnt = 0; 384 suptr->un_proc = td->td_proc; 385 return(suptr); 386 } 387 } 388 389 /* 390 * We didn't find a free one, if this is the first attempt 391 * then try to free a structure. 392 */ 393 394 if (attempt == 0) { 395 /* All the structures are in use - try to free one */ 396 int did_something = 0; 397 398 SLIST_FOREACH_PREVPTR(suptr, supptr, &semu_list, 399 un_next) { 400 if (suptr->un_cnt == 0) { 401 suptr->un_proc = NULL; 402 did_something = 1; 403 *supptr = SLIST_NEXT(suptr, un_next); 404 break; 405 } 406 } 407 408 /* If we didn't free anything then just give-up */ 409 if (!did_something) 410 return(NULL); 411 } else { 412 /* 413 * The second pass failed even though we freed 414 * something after the first pass! 415 * This is IMPOSSIBLE! 416 */ 417 panic("semu_alloc - second attempt failed"); 418 } 419 } 420 return (NULL); 421 } 422 423 /* 424 * Adjust a particular entry for a particular proc 425 */ 426 427 static int 428 semundo_adjust(td, supptr, semid, semnum, adjval) 429 struct thread *td; 430 struct sem_undo **supptr; 431 int semid, semnum; 432 int adjval; 433 { 434 struct proc *p = td->td_proc; 435 struct sem_undo *suptr; 436 struct undo *sunptr; 437 int i; 438 439 SEMUNDO_LOCKASSERT(MA_OWNED); 440 /* Look for and remember the sem_undo if the caller doesn't provide 441 it */ 442 443 suptr = *supptr; 444 if (suptr == NULL) { 445 SLIST_FOREACH(suptr, &semu_list, un_next) { 446 if (suptr->un_proc == p) { 447 *supptr = suptr; 448 break; 449 } 450 } 451 if (suptr == NULL) { 452 if (adjval == 0) 453 return(0); 454 suptr = semu_alloc(td); 455 if (suptr == NULL) 456 return(ENOSPC); 457 *supptr = suptr; 458 } 459 } 460 461 /* 462 * Look for the requested entry and adjust it (delete if adjval becomes 463 * 0). 464 */ 465 sunptr = &suptr->un_ent[0]; 466 for (i = 0; i < suptr->un_cnt; i++, sunptr++) { 467 if (sunptr->un_id != semid || sunptr->un_num != semnum) 468 continue; 469 if (adjval != 0) { 470 adjval += sunptr->un_adjval; 471 if (adjval > seminfo.semaem || adjval < -seminfo.semaem) 472 return (ERANGE); 473 } 474 sunptr->un_adjval = adjval; 475 if (sunptr->un_adjval == 0) { 476 suptr->un_cnt--; 477 if (i < suptr->un_cnt) 478 suptr->un_ent[i] = 479 suptr->un_ent[suptr->un_cnt]; 480 } 481 return(0); 482 } 483 484 /* Didn't find the right entry - create it */ 485 if (adjval == 0) 486 return(0); 487 if (adjval > seminfo.semaem || adjval < -seminfo.semaem) 488 return (ERANGE); 489 if (suptr->un_cnt != seminfo.semume) { 490 sunptr = &suptr->un_ent[suptr->un_cnt]; 491 suptr->un_cnt++; 492 sunptr->un_adjval = adjval; 493 sunptr->un_id = semid; sunptr->un_num = semnum; 494 } else 495 return(EINVAL); 496 return(0); 497 } 498 499 static void 500 semundo_clear(semid, semnum) 501 int semid, semnum; 502 { 503 struct sem_undo *suptr; 504 505 SEMUNDO_LOCKASSERT(MA_OWNED); 506 SLIST_FOREACH(suptr, &semu_list, un_next) { 507 struct undo *sunptr = &suptr->un_ent[0]; 508 int i = 0; 509 510 while (i < suptr->un_cnt) { 511 if (sunptr->un_id == semid) { 512 if (semnum == -1 || sunptr->un_num == semnum) { 513 suptr->un_cnt--; 514 if (i < suptr->un_cnt) { 515 suptr->un_ent[i] = 516 suptr->un_ent[suptr->un_cnt]; 517 continue; 518 } 519 } 520 if (semnum != -1) 521 break; 522 } 523 i++, sunptr++; 524 } 525 } 526 } 527 528 static int 529 semvalid(semid, semakptr) 530 int semid; 531 struct semid_kernel *semakptr; 532 { 533 534 return ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0 || 535 semakptr->u.sem_perm.seq != IPCID_TO_SEQ(semid) ? EINVAL : 0); 536 } 537 538 /* 539 * Note that the user-mode half of this passes a union, not a pointer 540 */ 541 #ifndef _SYS_SYSPROTO_H_ 542 struct __semctl_args { 543 int semid; 544 int semnum; 545 int cmd; 546 union semun *arg; 547 }; 548 #endif 549 550 /* 551 * MPSAFE 552 */ 553 int 554 __semctl(td, uap) 555 struct thread *td; 556 struct __semctl_args *uap; 557 { 558 int semid = uap->semid; 559 int semnum = uap->semnum; 560 int cmd = uap->cmd; 561 u_short *array; 562 union semun *arg = uap->arg; 563 union semun real_arg; 564 struct ucred *cred = td->td_ucred; 565 int i, rval, error; 566 struct semid_ds sbuf; 567 struct semid_kernel *semakptr; 568 struct mtx *sema_mtxp; 569 u_short usval, count; 570 571 DPRINTF(("call to semctl(%d, %d, %d, 0x%x)\n", 572 semid, semnum, cmd, arg)); 573 if (!jail_sysvipc_allowed && jailed(td->td_ucred)) 574 return (ENOSYS); 575 576 array = NULL; 577 578 switch(cmd) { 579 case SEM_STAT: 580 if (semid < 0 || semid >= seminfo.semmni) 581 return (EINVAL); 582 if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) 583 return (error); 584 semakptr = &sema[semid]; 585 sema_mtxp = &sema_mtx[semid]; 586 mtx_lock(sema_mtxp); 587 if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0) { 588 error = EINVAL; 589 goto done2; 590 } 591 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R))) 592 goto done2; 593 #ifdef MAC 594 error = mac_check_sysv_semctl(cred, semakptr, cmd); 595 if (error != 0) { 596 MPRINTF(("mac_check_sysv_semctl returned %d\n", 597 error)); 598 goto done2; 599 } 600 #endif 601 mtx_unlock(sema_mtxp); 602 error = copyout(&semakptr->u, real_arg.buf, 603 sizeof(struct semid_ds)); 604 rval = IXSEQ_TO_IPCID(semid, semakptr->u.sem_perm); 605 if (error == 0) 606 td->td_retval[0] = rval; 607 return (error); 608 } 609 610 semid = IPCID_TO_IX(semid); 611 if (semid < 0 || semid >= seminfo.semmni) 612 return (EINVAL); 613 614 semakptr = &sema[semid]; 615 sema_mtxp = &sema_mtx[semid]; 616 #ifdef MAC 617 mtx_lock(sema_mtxp); 618 error = mac_check_sysv_semctl(cred, semakptr, cmd); 619 if (error != 0) { 620 MPRINTF(("mac_check_sysv_semctl returned %d\n", error)); 621 mtx_unlock(sema_mtxp); 622 return (error); 623 } 624 mtx_unlock(sema_mtxp); 625 #endif 626 627 error = 0; 628 rval = 0; 629 630 switch (cmd) { 631 case IPC_RMID: 632 mtx_lock(sema_mtxp); 633 if ((error = semvalid(uap->semid, semakptr)) != 0) 634 goto done2; 635 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_M))) 636 goto done2; 637 semakptr->u.sem_perm.cuid = cred->cr_uid; 638 semakptr->u.sem_perm.uid = cred->cr_uid; 639 semtot -= semakptr->u.sem_nsems; 640 for (i = semakptr->u.sem_base - sem; i < semtot; i++) 641 sem[i] = sem[i + semakptr->u.sem_nsems]; 642 for (i = 0; i < seminfo.semmni; i++) { 643 if ((sema[i].u.sem_perm.mode & SEM_ALLOC) && 644 sema[i].u.sem_base > semakptr->u.sem_base) 645 sema[i].u.sem_base -= semakptr->u.sem_nsems; 646 } 647 semakptr->u.sem_perm.mode = 0; 648 #ifdef MAC 649 mac_cleanup_sysv_sema(semakptr); 650 #endif 651 SEMUNDO_LOCK(); 652 semundo_clear(semid, -1); 653 SEMUNDO_UNLOCK(); 654 wakeup(semakptr); 655 break; 656 657 case IPC_SET: 658 if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) 659 goto done2; 660 if ((error = copyin(real_arg.buf, &sbuf, sizeof(sbuf))) != 0) 661 goto done2; 662 mtx_lock(sema_mtxp); 663 if ((error = semvalid(uap->semid, semakptr)) != 0) 664 goto done2; 665 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_M))) 666 goto done2; 667 semakptr->u.sem_perm.uid = sbuf.sem_perm.uid; 668 semakptr->u.sem_perm.gid = sbuf.sem_perm.gid; 669 semakptr->u.sem_perm.mode = (semakptr->u.sem_perm.mode & 670 ~0777) | (sbuf.sem_perm.mode & 0777); 671 semakptr->u.sem_ctime = time_second; 672 break; 673 674 case IPC_STAT: 675 if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) 676 goto done2; 677 mtx_lock(sema_mtxp); 678 if ((error = semvalid(uap->semid, semakptr)) != 0) 679 goto done2; 680 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R))) 681 goto done2; 682 sbuf = semakptr->u; 683 mtx_unlock(sema_mtxp); 684 error = copyout(&semakptr->u, real_arg.buf, 685 sizeof(struct semid_ds)); 686 break; 687 688 case GETNCNT: 689 mtx_lock(sema_mtxp); 690 if ((error = semvalid(uap->semid, semakptr)) != 0) 691 goto done2; 692 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R))) 693 goto done2; 694 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) { 695 error = EINVAL; 696 goto done2; 697 } 698 rval = semakptr->u.sem_base[semnum].semncnt; 699 break; 700 701 case GETPID: 702 mtx_lock(sema_mtxp); 703 if ((error = semvalid(uap->semid, semakptr)) != 0) 704 goto done2; 705 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R))) 706 goto done2; 707 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) { 708 error = EINVAL; 709 goto done2; 710 } 711 rval = semakptr->u.sem_base[semnum].sempid; 712 break; 713 714 case GETVAL: 715 mtx_lock(sema_mtxp); 716 if ((error = semvalid(uap->semid, semakptr)) != 0) 717 goto done2; 718 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R))) 719 goto done2; 720 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) { 721 error = EINVAL; 722 goto done2; 723 } 724 rval = semakptr->u.sem_base[semnum].semval; 725 break; 726 727 case GETALL: 728 if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) 729 goto done2; 730 array = malloc(sizeof(*array) * semakptr->u.sem_nsems, M_TEMP, 731 M_WAITOK); 732 mtx_lock(sema_mtxp); 733 if ((error = semvalid(uap->semid, semakptr)) != 0) 734 goto done2; 735 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R))) 736 goto done2; 737 for (i = 0; i < semakptr->u.sem_nsems; i++) 738 array[i] = semakptr->u.sem_base[i].semval; 739 mtx_unlock(sema_mtxp); 740 error = copyout(array, real_arg.array, 741 i * sizeof(real_arg.array[0])); 742 break; 743 744 case GETZCNT: 745 mtx_lock(sema_mtxp); 746 if ((error = semvalid(uap->semid, semakptr)) != 0) 747 goto done2; 748 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R))) 749 goto done2; 750 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) { 751 error = EINVAL; 752 goto done2; 753 } 754 rval = semakptr->u.sem_base[semnum].semzcnt; 755 break; 756 757 case SETVAL: 758 if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) 759 goto done2; 760 mtx_lock(sema_mtxp); 761 if ((error = semvalid(uap->semid, semakptr)) != 0) 762 goto done2; 763 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_W))) 764 goto done2; 765 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) { 766 error = EINVAL; 767 goto done2; 768 } 769 if (real_arg.val < 0 || real_arg.val > seminfo.semvmx) { 770 error = ERANGE; 771 goto done2; 772 } 773 semakptr->u.sem_base[semnum].semval = real_arg.val; 774 SEMUNDO_LOCK(); 775 semundo_clear(semid, semnum); 776 SEMUNDO_UNLOCK(); 777 wakeup(semakptr); 778 break; 779 780 case SETALL: 781 mtx_lock(sema_mtxp); 782 raced: 783 if ((error = semvalid(uap->semid, semakptr)) != 0) 784 goto done2; 785 count = semakptr->u.sem_nsems; 786 mtx_unlock(sema_mtxp); 787 if ((error = copyin(arg, &real_arg, sizeof(real_arg))) != 0) 788 goto done2; 789 array = malloc(sizeof(*array) * count, M_TEMP, M_WAITOK); 790 copyin(real_arg.array, array, count * sizeof(*array)); 791 if (error) 792 break; 793 mtx_lock(sema_mtxp); 794 if ((error = semvalid(uap->semid, semakptr)) != 0) 795 goto done2; 796 /* we could have raced? */ 797 if (count != semakptr->u.sem_nsems) { 798 free(array, M_TEMP); 799 array = NULL; 800 goto raced; 801 } 802 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_W))) 803 goto done2; 804 for (i = 0; i < semakptr->u.sem_nsems; i++) { 805 usval = array[i]; 806 if (usval > seminfo.semvmx) { 807 error = ERANGE; 808 break; 809 } 810 semakptr->u.sem_base[i].semval = usval; 811 } 812 SEMUNDO_LOCK(); 813 semundo_clear(semid, -1); 814 SEMUNDO_UNLOCK(); 815 wakeup(semakptr); 816 break; 817 818 default: 819 error = EINVAL; 820 break; 821 } 822 823 if (error == 0) 824 td->td_retval[0] = rval; 825 done2: 826 if (mtx_owned(sema_mtxp)) 827 mtx_unlock(sema_mtxp); 828 if (array != NULL) 829 free(array, M_TEMP); 830 return(error); 831 } 832 833 #ifndef _SYS_SYSPROTO_H_ 834 struct semget_args { 835 key_t key; 836 int nsems; 837 int semflg; 838 }; 839 #endif 840 841 /* 842 * MPSAFE 843 */ 844 int 845 semget(td, uap) 846 struct thread *td; 847 struct semget_args *uap; 848 { 849 int semid, error = 0; 850 int key = uap->key; 851 int nsems = uap->nsems; 852 int semflg = uap->semflg; 853 struct ucred *cred = td->td_ucred; 854 855 DPRINTF(("semget(0x%x, %d, 0%o)\n", key, nsems, semflg)); 856 if (!jail_sysvipc_allowed && jailed(td->td_ucred)) 857 return (ENOSYS); 858 859 mtx_lock(&Giant); 860 if (key != IPC_PRIVATE) { 861 for (semid = 0; semid < seminfo.semmni; semid++) { 862 if ((sema[semid].u.sem_perm.mode & SEM_ALLOC) && 863 sema[semid].u.sem_perm.key == key) 864 break; 865 } 866 if (semid < seminfo.semmni) { 867 DPRINTF(("found public key\n")); 868 if ((error = ipcperm(td, &sema[semid].u.sem_perm, 869 semflg & 0700))) { 870 goto done2; 871 } 872 if (nsems > 0 && sema[semid].u.sem_nsems < nsems) { 873 DPRINTF(("too small\n")); 874 error = EINVAL; 875 goto done2; 876 } 877 if ((semflg & IPC_CREAT) && (semflg & IPC_EXCL)) { 878 DPRINTF(("not exclusive\n")); 879 error = EEXIST; 880 goto done2; 881 } 882 #ifdef MAC 883 error = mac_check_sysv_semget(cred, &sema[semid]); 884 if (error != 0) { 885 MPRINTF(("mac_check_sysv_semget returned %d\n", 886 error)); 887 goto done2; 888 } 889 #endif 890 goto found; 891 } 892 } 893 894 DPRINTF(("need to allocate the semid_kernel\n")); 895 if (key == IPC_PRIVATE || (semflg & IPC_CREAT)) { 896 if (nsems <= 0 || nsems > seminfo.semmsl) { 897 DPRINTF(("nsems out of range (0<%d<=%d)\n", nsems, 898 seminfo.semmsl)); 899 error = EINVAL; 900 goto done2; 901 } 902 if (nsems > seminfo.semmns - semtot) { 903 DPRINTF(( 904 "not enough semaphores left (need %d, got %d)\n", 905 nsems, seminfo.semmns - semtot)); 906 error = ENOSPC; 907 goto done2; 908 } 909 for (semid = 0; semid < seminfo.semmni; semid++) { 910 if ((sema[semid].u.sem_perm.mode & SEM_ALLOC) == 0) 911 break; 912 } 913 if (semid == seminfo.semmni) { 914 DPRINTF(("no more semid_kernel's available\n")); 915 error = ENOSPC; 916 goto done2; 917 } 918 DPRINTF(("semid %d is available\n", semid)); 919 sema[semid].u.sem_perm.key = key; 920 sema[semid].u.sem_perm.cuid = cred->cr_uid; 921 sema[semid].u.sem_perm.uid = cred->cr_uid; 922 sema[semid].u.sem_perm.cgid = cred->cr_gid; 923 sema[semid].u.sem_perm.gid = cred->cr_gid; 924 sema[semid].u.sem_perm.mode = (semflg & 0777) | SEM_ALLOC; 925 sema[semid].u.sem_perm.seq = 926 (sema[semid].u.sem_perm.seq + 1) & 0x7fff; 927 sema[semid].u.sem_nsems = nsems; 928 sema[semid].u.sem_otime = 0; 929 sema[semid].u.sem_ctime = time_second; 930 sema[semid].u.sem_base = &sem[semtot]; 931 semtot += nsems; 932 bzero(sema[semid].u.sem_base, 933 sizeof(sema[semid].u.sem_base[0])*nsems); 934 #ifdef MAC 935 mac_create_sysv_sema(cred, &sema[semid]); 936 #endif 937 DPRINTF(("sembase = 0x%x, next = 0x%x\n", 938 sema[semid].u.sem_base, &sem[semtot])); 939 } else { 940 DPRINTF(("didn't find it and wasn't asked to create it\n")); 941 error = ENOENT; 942 goto done2; 943 } 944 945 found: 946 td->td_retval[0] = IXSEQ_TO_IPCID(semid, sema[semid].u.sem_perm); 947 done2: 948 mtx_unlock(&Giant); 949 return (error); 950 } 951 952 #ifndef _SYS_SYSPROTO_H_ 953 struct semop_args { 954 int semid; 955 struct sembuf *sops; 956 size_t nsops; 957 }; 958 #endif 959 960 /* 961 * MPSAFE 962 */ 963 int 964 semop(td, uap) 965 struct thread *td; 966 struct semop_args *uap; 967 { 968 #define SMALL_SOPS 8 969 struct sembuf small_sops[SMALL_SOPS]; 970 int semid = uap->semid; 971 size_t nsops = uap->nsops; 972 struct sembuf *sops; 973 struct semid_kernel *semakptr; 974 struct sembuf *sopptr = 0; 975 struct sem *semptr = 0; 976 struct sem_undo *suptr; 977 struct mtx *sema_mtxp; 978 size_t i, j, k; 979 int error; 980 int do_wakeup, do_undos; 981 982 DPRINTF(("call to semop(%d, 0x%x, %u)\n", semid, sops, nsops)); 983 984 if (!jail_sysvipc_allowed && jailed(td->td_ucred)) 985 return (ENOSYS); 986 987 semid = IPCID_TO_IX(semid); /* Convert back to zero origin */ 988 989 if (semid < 0 || semid >= seminfo.semmni) 990 return (EINVAL); 991 992 /* Allocate memory for sem_ops */ 993 if (nsops <= SMALL_SOPS) 994 sops = small_sops; 995 else if (nsops <= seminfo.semopm) 996 sops = malloc(nsops * sizeof(*sops), M_TEMP, M_WAITOK); 997 else { 998 DPRINTF(("too many sops (max=%d, nsops=%d)\n", seminfo.semopm, 999 nsops)); 1000 return (E2BIG); 1001 } 1002 if ((error = copyin(uap->sops, sops, nsops * sizeof(sops[0]))) != 0) { 1003 DPRINTF(("error = %d from copyin(%08x, %08x, %d)\n", error, 1004 uap->sops, sops, nsops * sizeof(sops[0]))); 1005 if (sops != small_sops) 1006 free(sops, M_SEM); 1007 return (error); 1008 } 1009 1010 semakptr = &sema[semid]; 1011 sema_mtxp = &sema_mtx[semid]; 1012 mtx_lock(sema_mtxp); 1013 if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0) { 1014 error = EINVAL; 1015 goto done2; 1016 } 1017 if (semakptr->u.sem_perm.seq != IPCID_TO_SEQ(uap->semid)) { 1018 error = EINVAL; 1019 goto done2; 1020 } 1021 /* 1022 * Initial pass thru sops to see what permissions are needed. 1023 * Also perform any checks that don't need repeating on each 1024 * attempt to satisfy the request vector. 1025 */ 1026 j = 0; /* permission needed */ 1027 do_undos = 0; 1028 for (i = 0; i < nsops; i++) { 1029 sopptr = &sops[i]; 1030 if (sopptr->sem_num >= semakptr->u.sem_nsems) { 1031 error = EFBIG; 1032 goto done2; 1033 } 1034 if (sopptr->sem_flg & SEM_UNDO && sopptr->sem_op != 0) 1035 do_undos = 1; 1036 j |= (sopptr->sem_op == 0) ? SEM_R : SEM_A; 1037 } 1038 1039 if ((error = ipcperm(td, &semakptr->u.sem_perm, j))) { 1040 DPRINTF(("error = %d from ipaccess\n", error)); 1041 goto done2; 1042 } 1043 #ifdef MAC 1044 error = mac_check_sysv_semop(td->td_ucred, semakptr, j); 1045 if (error != 0) { 1046 MPRINTF(("mac_check_sysv_semop returned %d\n", error)); 1047 goto done2; 1048 } 1049 #endif 1050 1051 /* 1052 * Loop trying to satisfy the vector of requests. 1053 * If we reach a point where we must wait, any requests already 1054 * performed are rolled back and we go to sleep until some other 1055 * process wakes us up. At this point, we start all over again. 1056 * 1057 * This ensures that from the perspective of other tasks, a set 1058 * of requests is atomic (never partially satisfied). 1059 */ 1060 for (;;) { 1061 do_wakeup = 0; 1062 error = 0; /* error return if necessary */ 1063 1064 for (i = 0; i < nsops; i++) { 1065 sopptr = &sops[i]; 1066 semptr = &semakptr->u.sem_base[sopptr->sem_num]; 1067 1068 DPRINTF(( 1069 "semop: semakptr=%x, sem_base=%x, " 1070 "semptr=%x, sem[%d]=%d : op=%d, flag=%s\n", 1071 semakptr, semakptr->u.sem_base, semptr, 1072 sopptr->sem_num, semptr->semval, sopptr->sem_op, 1073 (sopptr->sem_flg & IPC_NOWAIT) ? 1074 "nowait" : "wait")); 1075 1076 if (sopptr->sem_op < 0) { 1077 if (semptr->semval + sopptr->sem_op < 0) { 1078 DPRINTF(("semop: can't do it now\n")); 1079 break; 1080 } else { 1081 semptr->semval += sopptr->sem_op; 1082 if (semptr->semval == 0 && 1083 semptr->semzcnt > 0) 1084 do_wakeup = 1; 1085 } 1086 } else if (sopptr->sem_op == 0) { 1087 if (semptr->semval != 0) { 1088 DPRINTF(("semop: not zero now\n")); 1089 break; 1090 } 1091 } else if (semptr->semval + sopptr->sem_op > 1092 seminfo.semvmx) { 1093 error = ERANGE; 1094 break; 1095 } else { 1096 if (semptr->semncnt > 0) 1097 do_wakeup = 1; 1098 semptr->semval += sopptr->sem_op; 1099 } 1100 } 1101 1102 /* 1103 * Did we get through the entire vector? 1104 */ 1105 if (i >= nsops) 1106 goto done; 1107 1108 /* 1109 * No ... rollback anything that we've already done 1110 */ 1111 DPRINTF(("semop: rollback 0 through %d\n", i-1)); 1112 for (j = 0; j < i; j++) 1113 semakptr->u.sem_base[sops[j].sem_num].semval -= 1114 sops[j].sem_op; 1115 1116 /* If we detected an error, return it */ 1117 if (error != 0) 1118 goto done2; 1119 1120 /* 1121 * If the request that we couldn't satisfy has the 1122 * NOWAIT flag set then return with EAGAIN. 1123 */ 1124 if (sopptr->sem_flg & IPC_NOWAIT) { 1125 error = EAGAIN; 1126 goto done2; 1127 } 1128 1129 if (sopptr->sem_op == 0) 1130 semptr->semzcnt++; 1131 else 1132 semptr->semncnt++; 1133 1134 DPRINTF(("semop: good night!\n")); 1135 error = msleep(semakptr, sema_mtxp, (PZERO - 4) | PCATCH, 1136 "semwait", 0); 1137 DPRINTF(("semop: good morning (error=%d)!\n", error)); 1138 /* return code is checked below, after sem[nz]cnt-- */ 1139 1140 /* 1141 * Make sure that the semaphore still exists 1142 */ 1143 if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0 || 1144 semakptr->u.sem_perm.seq != IPCID_TO_SEQ(uap->semid)) { 1145 error = EIDRM; 1146 goto done2; 1147 } 1148 1149 /* 1150 * The semaphore is still alive. Readjust the count of 1151 * waiting processes. 1152 */ 1153 if (sopptr->sem_op == 0) 1154 semptr->semzcnt--; 1155 else 1156 semptr->semncnt--; 1157 1158 /* 1159 * Is it really morning, or was our sleep interrupted? 1160 * (Delayed check of msleep() return code because we 1161 * need to decrement sem[nz]cnt either way.) 1162 */ 1163 if (error != 0) { 1164 error = EINTR; 1165 goto done2; 1166 } 1167 DPRINTF(("semop: good morning!\n")); 1168 } 1169 1170 done: 1171 /* 1172 * Process any SEM_UNDO requests. 1173 */ 1174 if (do_undos) { 1175 SEMUNDO_LOCK(); 1176 suptr = NULL; 1177 for (i = 0; i < nsops; i++) { 1178 /* 1179 * We only need to deal with SEM_UNDO's for non-zero 1180 * op's. 1181 */ 1182 int adjval; 1183 1184 if ((sops[i].sem_flg & SEM_UNDO) == 0) 1185 continue; 1186 adjval = sops[i].sem_op; 1187 if (adjval == 0) 1188 continue; 1189 error = semundo_adjust(td, &suptr, semid, 1190 sops[i].sem_num, -adjval); 1191 if (error == 0) 1192 continue; 1193 1194 /* 1195 * Oh-Oh! We ran out of either sem_undo's or undo's. 1196 * Rollback the adjustments to this point and then 1197 * rollback the semaphore ups and down so we can return 1198 * with an error with all structures restored. We 1199 * rollback the undo's in the exact reverse order that 1200 * we applied them. This guarantees that we won't run 1201 * out of space as we roll things back out. 1202 */ 1203 for (j = 0; j < i; j++) { 1204 k = i - j - 1; 1205 if ((sops[k].sem_flg & SEM_UNDO) == 0) 1206 continue; 1207 adjval = sops[k].sem_op; 1208 if (adjval == 0) 1209 continue; 1210 if (semundo_adjust(td, &suptr, semid, 1211 sops[k].sem_num, adjval) != 0) 1212 panic("semop - can't undo undos"); 1213 } 1214 1215 for (j = 0; j < nsops; j++) 1216 semakptr->u.sem_base[sops[j].sem_num].semval -= 1217 sops[j].sem_op; 1218 1219 DPRINTF(("error = %d from semundo_adjust\n", error)); 1220 SEMUNDO_UNLOCK(); 1221 goto done2; 1222 } /* loop through the sops */ 1223 SEMUNDO_UNLOCK(); 1224 } /* if (do_undos) */ 1225 1226 /* We're definitely done - set the sempid's and time */ 1227 for (i = 0; i < nsops; i++) { 1228 sopptr = &sops[i]; 1229 semptr = &semakptr->u.sem_base[sopptr->sem_num]; 1230 semptr->sempid = td->td_proc->p_pid; 1231 } 1232 semakptr->u.sem_otime = time_second; 1233 1234 /* 1235 * Do a wakeup if any semaphore was up'd whilst something was 1236 * sleeping on it. 1237 */ 1238 if (do_wakeup) { 1239 DPRINTF(("semop: doing wakeup\n")); 1240 wakeup(semakptr); 1241 DPRINTF(("semop: back from wakeup\n")); 1242 } 1243 DPRINTF(("semop: done\n")); 1244 td->td_retval[0] = 0; 1245 done2: 1246 mtx_unlock(sema_mtxp); 1247 if (sops != small_sops) 1248 free(sops, M_SEM); 1249 return (error); 1250 } 1251 1252 /* 1253 * Go through the undo structures for this process and apply the adjustments to 1254 * semaphores. 1255 */ 1256 static void 1257 semexit_myhook(arg, p) 1258 void *arg; 1259 struct proc *p; 1260 { 1261 struct sem_undo *suptr; 1262 struct sem_undo **supptr; 1263 1264 /* 1265 * Go through the chain of undo vectors looking for one 1266 * associated with this process. 1267 */ 1268 SEMUNDO_LOCK(); 1269 SLIST_FOREACH_PREVPTR(suptr, supptr, &semu_list, un_next) { 1270 if (suptr->un_proc == p) 1271 break; 1272 } 1273 SEMUNDO_UNLOCK(); 1274 1275 if (suptr == NULL) 1276 return; 1277 1278 DPRINTF(("proc @%08x has undo structure with %d entries\n", p, 1279 suptr->un_cnt)); 1280 1281 /* 1282 * If there are any active undo elements then process them. 1283 */ 1284 if (suptr->un_cnt > 0) { 1285 int ix; 1286 1287 for (ix = 0; ix < suptr->un_cnt; ix++) { 1288 int semid = suptr->un_ent[ix].un_id; 1289 int semnum = suptr->un_ent[ix].un_num; 1290 int adjval = suptr->un_ent[ix].un_adjval; 1291 struct semid_kernel *semakptr; 1292 struct mtx *sema_mtxp; 1293 1294 semakptr = &sema[semid]; 1295 sema_mtxp = &sema_mtx[semid]; 1296 mtx_lock(sema_mtxp); 1297 SEMUNDO_LOCK(); 1298 if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0) 1299 panic("semexit - semid not allocated"); 1300 if (semnum >= semakptr->u.sem_nsems) 1301 panic("semexit - semnum out of range"); 1302 1303 DPRINTF(( 1304 "semexit: %08x id=%d num=%d(adj=%d) ; sem=%d\n", 1305 suptr->un_proc, suptr->un_ent[ix].un_id, 1306 suptr->un_ent[ix].un_num, 1307 suptr->un_ent[ix].un_adjval, 1308 semakptr->u.sem_base[semnum].semval)); 1309 1310 if (adjval < 0) { 1311 if (semakptr->u.sem_base[semnum].semval < 1312 -adjval) 1313 semakptr->u.sem_base[semnum].semval = 0; 1314 else 1315 semakptr->u.sem_base[semnum].semval += 1316 adjval; 1317 } else 1318 semakptr->u.sem_base[semnum].semval += adjval; 1319 1320 wakeup(semakptr); 1321 DPRINTF(("semexit: back from wakeup\n")); 1322 mtx_unlock(sema_mtxp); 1323 SEMUNDO_UNLOCK(); 1324 } 1325 } 1326 1327 /* 1328 * Deallocate the undo vector. 1329 */ 1330 DPRINTF(("removing vector\n")); 1331 suptr->un_proc = NULL; 1332 *supptr = SLIST_NEXT(suptr, un_next); 1333 } 1334 1335 static int 1336 sysctl_sema(SYSCTL_HANDLER_ARGS) 1337 { 1338 1339 return (SYSCTL_OUT(req, sema, 1340 sizeof(struct semid_kernel) * seminfo.semmni)); 1341 } 1342