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 * SPDX-License-Identifier: BSD-2-Clause
10 *
11 * Copyright (c) 2003-2005 McAfee, Inc.
12 * Copyright (c) 2016-2017 Robert N. M. Watson
13 * All rights reserved.
14 *
15 * This software was developed for the FreeBSD Project in part by McAfee
16 * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR
17 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research
18 * program.
19 *
20 * Portions of this software were developed by BAE Systems, the University of
21 * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL
22 * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent
23 * Computing (TC) research program.
24 *
25 * Redistribution and use in source and binary forms, with or without
26 * modification, are permitted provided that the following conditions
27 * are met:
28 * 1. Redistributions of source code must retain the above copyright
29 * notice, this list of conditions and the following disclaimer.
30 * 2. Redistributions in binary form must reproduce the above copyright
31 * notice, this list of conditions and the following disclaimer in the
32 * documentation and/or other materials provided with the distribution.
33 *
34 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
35 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
36 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
37 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
38 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
39 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
40 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
41 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
42 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
43 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44 * SUCH DAMAGE.
45 */
46
47 #include <sys/cdefs.h>
48 #include "opt_sysvipc.h"
49
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/sysproto.h>
53 #include <sys/abi_compat.h>
54 #include <sys/eventhandler.h>
55 #include <sys/kernel.h>
56 #include <sys/proc.h>
57 #include <sys/lock.h>
58 #include <sys/module.h>
59 #include <sys/mutex.h>
60 #include <sys/racct.h>
61 #include <sys/sem.h>
62 #include <sys/sx.h>
63 #include <sys/syscall.h>
64 #include <sys/syscallsubr.h>
65 #include <sys/sysent.h>
66 #include <sys/sysctl.h>
67 #include <sys/uio.h>
68 #include <sys/malloc.h>
69 #include <sys/jail.h>
70
71 #include <security/audit/audit.h>
72 #include <security/mac/mac_framework.h>
73
74 FEATURE(sysv_sem, "System V semaphores support");
75
76 static MALLOC_DEFINE(M_SEM, "sem", "SVID compatible semaphores");
77
78 #ifdef SEM_DEBUG
79 #define DPRINTF(a) printf a
80 #else
81 #define DPRINTF(a)
82 #endif
83
84 static int seminit(void);
85 static int sysvsem_modload(struct module *, int, void *);
86 static int semunload(void);
87 static void semexit_myhook(void *arg, struct proc *p);
88 static int sysctl_sema(SYSCTL_HANDLER_ARGS);
89 static int semvalid(int semid, struct prison *rpr,
90 struct semid_kernel *semakptr);
91 static void sem_remove(int semidx, struct ucred *cred);
92 static struct prison *sem_find_prison(struct ucred *);
93 static int sem_prison_cansee(struct prison *, struct semid_kernel *);
94 static int sem_prison_check(void *, void *);
95 static int sem_prison_set(void *, void *);
96 static int sem_prison_get(void *, void *);
97 static int sem_prison_remove(void *, void *);
98 static void sem_prison_cleanup(struct prison *);
99
100 #ifndef _SYS_SYSPROTO_H_
101 struct __semctl_args;
102 int __semctl(struct thread *td, struct __semctl_args *uap);
103 struct semget_args;
104 int semget(struct thread *td, struct semget_args *uap);
105 struct semop_args;
106 int semop(struct thread *td, struct semop_args *uap);
107 #endif
108
109 static struct sem_undo *semu_alloc(struct thread *td);
110 static int semundo_adjust(struct thread *td, struct sem_undo **supptr,
111 int semid, int semseq, int semnum, int adjval);
112 static void semundo_clear(int semid, int semnum);
113
114 static struct mtx sem_mtx; /* semaphore global lock */
115 static struct mtx sem_undo_mtx;
116 static int semtot = 0;
117 static struct semid_kernel *sema; /* semaphore id pool */
118 static struct mtx *sema_mtx; /* semaphore id pool mutexes*/
119 static struct sem *sem; /* semaphore pool */
120 LIST_HEAD(, sem_undo) semu_list; /* list of active undo structures */
121 LIST_HEAD(, sem_undo) semu_free_list; /* list of free undo structures */
122 static int *semu; /* undo structure pool */
123 static eventhandler_tag semexit_tag;
124 static unsigned sem_prison_slot; /* prison OSD slot */
125
126 #define SEMUNDO_MTX sem_undo_mtx
127 #define SEMUNDO_LOCK() mtx_lock(&SEMUNDO_MTX);
128 #define SEMUNDO_UNLOCK() mtx_unlock(&SEMUNDO_MTX);
129 #define SEMUNDO_LOCKASSERT(how) mtx_assert(&SEMUNDO_MTX, (how));
130
131 struct sem {
132 u_short semval; /* semaphore value */
133 pid_t sempid; /* pid of last operation */
134 u_short semncnt; /* # awaiting semval > cval */
135 u_short semzcnt; /* # awaiting semval = 0 */
136 };
137
138 /*
139 * Undo structure (one per process)
140 */
141 struct sem_undo {
142 LIST_ENTRY(sem_undo) un_next; /* ptr to next active undo structure */
143 struct proc *un_proc; /* owner of this structure */
144 short un_cnt; /* # of active entries */
145 struct undo {
146 short un_adjval; /* adjust on exit values */
147 short un_num; /* semaphore # */
148 int un_id; /* semid */
149 unsigned short un_seq;
150 } un_ent[1]; /* undo entries */
151 };
152
153 /*
154 * Configuration parameters
155 */
156 #ifndef SEMMNI
157 #define SEMMNI 50 /* # of semaphore identifiers */
158 #endif
159 #ifndef SEMMNS
160 #define SEMMNS 340 /* # of semaphores in system */
161 #endif
162 #ifndef SEMUME
163 #define SEMUME 50 /* max # of undo entries per process */
164 #endif
165 #ifndef SEMMNU
166 #define SEMMNU 150 /* # of undo structures in system */
167 #endif
168
169 /* shouldn't need tuning */
170 #ifndef SEMMSL
171 #define SEMMSL SEMMNS /* max # of semaphores per id */
172 #endif
173 #ifndef SEMOPM
174 #define SEMOPM 100 /* max # of operations per semop call */
175 #endif
176
177 #define SEMVMX 32767 /* semaphore maximum value */
178 #define SEMAEM 16384 /* adjust on exit max value */
179
180 /*
181 * Due to the way semaphore memory is allocated, we have to ensure that
182 * SEMUSZ is properly aligned.
183 */
184
185 #define SEM_ALIGN(bytes) roundup2(bytes, sizeof(long))
186
187 /* actual size of an undo structure */
188 #define SEMUSZ(x) SEM_ALIGN(offsetof(struct sem_undo, un_ent[(x)]))
189
190 /*
191 * Macro to find a particular sem_undo vector
192 */
193 #define SEMU(ix) \
194 ((struct sem_undo *)(((intptr_t)semu) + (ix) * seminfo.semusz))
195
196 /*
197 * semaphore info struct
198 */
199 struct seminfo seminfo = {
200 .semmni = SEMMNI, /* # of semaphore identifiers */
201 .semmns = SEMMNS, /* # of semaphores in system */
202 .semmnu = SEMMNU, /* # of undo structures in system */
203 .semmsl = SEMMSL, /* max # of semaphores per id */
204 .semopm = SEMOPM, /* max # of operations per semop call */
205 .semume = SEMUME, /* max # of undo entries per process */
206 .semusz = SEMUSZ(SEMUME), /* size in bytes of undo structure */
207 .semvmx = SEMVMX, /* semaphore maximum value */
208 .semaem = SEMAEM, /* adjust on exit max value */
209 };
210
211 SYSCTL_INT(_kern_ipc, OID_AUTO, semmni, CTLFLAG_RDTUN, &seminfo.semmni, 0,
212 "Number of semaphore identifiers");
213 SYSCTL_INT(_kern_ipc, OID_AUTO, semmns, CTLFLAG_RDTUN, &seminfo.semmns, 0,
214 "Maximum number of semaphores in the system");
215 SYSCTL_INT(_kern_ipc, OID_AUTO, semmnu, CTLFLAG_RDTUN, &seminfo.semmnu, 0,
216 "Maximum number of undo structures in the system");
217 SYSCTL_INT(_kern_ipc, OID_AUTO, semmsl, CTLFLAG_RWTUN, &seminfo.semmsl, 0,
218 "Max semaphores per id");
219 SYSCTL_INT(_kern_ipc, OID_AUTO, semopm, CTLFLAG_RDTUN, &seminfo.semopm, 0,
220 "Max operations per semop call");
221 SYSCTL_INT(_kern_ipc, OID_AUTO, semume, CTLFLAG_RDTUN, &seminfo.semume, 0,
222 "Max undo entries per process");
223 SYSCTL_INT(_kern_ipc, OID_AUTO, semusz, CTLFLAG_RD, &seminfo.semusz, 0,
224 "Size in bytes of undo structure");
225 SYSCTL_INT(_kern_ipc, OID_AUTO, semvmx, CTLFLAG_RWTUN, &seminfo.semvmx, 0,
226 "Semaphore maximum value");
227 SYSCTL_INT(_kern_ipc, OID_AUTO, semaem, CTLFLAG_RWTUN, &seminfo.semaem, 0,
228 "Adjust on exit max value");
229 SYSCTL_PROC(_kern_ipc, OID_AUTO, sema,
230 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
231 NULL, 0, sysctl_sema, "",
232 "Array of struct semid_kernel for each potential semaphore");
233
234 static struct syscall_helper_data sem_syscalls[] = {
235 SYSCALL_INIT_HELPER(__semctl),
236 SYSCALL_INIT_HELPER(semget),
237 SYSCALL_INIT_HELPER(semop),
238 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
239 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
240 SYSCALL_INIT_HELPER(semsys),
241 SYSCALL_INIT_HELPER_COMPAT(freebsd7___semctl),
242 #endif
243 SYSCALL_INIT_LAST
244 };
245
246 #ifdef COMPAT_FREEBSD32
247 #include <compat/freebsd32/freebsd32.h>
248 #include <compat/freebsd32/freebsd32_ipc.h>
249 #include <compat/freebsd32/freebsd32_proto.h>
250 #include <compat/freebsd32/freebsd32_signal.h>
251 #include <compat/freebsd32/freebsd32_syscall.h>
252 #include <compat/freebsd32/freebsd32_util.h>
253
254 static struct syscall_helper_data sem32_syscalls[] = {
255 SYSCALL32_INIT_HELPER(freebsd32___semctl),
256 SYSCALL32_INIT_HELPER_COMPAT(semget),
257 SYSCALL32_INIT_HELPER_COMPAT(semop),
258 SYSCALL32_INIT_HELPER(freebsd32_semsys),
259 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
260 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
261 SYSCALL32_INIT_HELPER(freebsd7_freebsd32___semctl),
262 #endif
263 SYSCALL_INIT_LAST
264 };
265 #endif
266
267 static int
seminit(void)268 seminit(void)
269 {
270 struct prison *pr;
271 void **rsv;
272 int i, error;
273 osd_method_t methods[PR_MAXMETHOD] = {
274 [PR_METHOD_CHECK] = sem_prison_check,
275 [PR_METHOD_SET] = sem_prison_set,
276 [PR_METHOD_GET] = sem_prison_get,
277 [PR_METHOD_REMOVE] = sem_prison_remove,
278 };
279
280 sem = malloc(sizeof(struct sem) * seminfo.semmns, M_SEM, M_WAITOK);
281 sema = malloc(sizeof(struct semid_kernel) * seminfo.semmni, M_SEM,
282 M_WAITOK | M_ZERO);
283 sema_mtx = malloc(sizeof(struct mtx) * seminfo.semmni, M_SEM,
284 M_WAITOK | M_ZERO);
285 seminfo.semusz = SEMUSZ(seminfo.semume);
286 semu = malloc(seminfo.semmnu * seminfo.semusz, M_SEM, M_WAITOK);
287
288 for (i = 0; i < seminfo.semmni; i++) {
289 sema[i].u.__sem_base = 0;
290 sema[i].u.sem_perm.mode = 0;
291 sema[i].u.sem_perm.seq = 0;
292 #ifdef MAC
293 mac_sysvsem_init(&sema[i]);
294 #endif
295 }
296 for (i = 0; i < seminfo.semmni; i++)
297 mtx_init(&sema_mtx[i], "semid", NULL, MTX_DEF);
298 LIST_INIT(&semu_free_list);
299 for (i = 0; i < seminfo.semmnu; i++) {
300 struct sem_undo *suptr = SEMU(i);
301 suptr->un_proc = NULL;
302 LIST_INSERT_HEAD(&semu_free_list, suptr, un_next);
303 }
304 LIST_INIT(&semu_list);
305 mtx_init(&sem_mtx, "sem", NULL, MTX_DEF);
306 mtx_init(&sem_undo_mtx, "semu", NULL, MTX_DEF);
307 semexit_tag = EVENTHANDLER_REGISTER(process_exit, semexit_myhook, NULL,
308 EVENTHANDLER_PRI_ANY);
309
310 /* Set current prisons according to their allow.sysvipc. */
311 sem_prison_slot = osd_jail_register(NULL, methods);
312 rsv = osd_reserve(sem_prison_slot);
313 prison_lock(&prison0);
314 (void)osd_jail_set_reserved(&prison0, sem_prison_slot, rsv, &prison0);
315 prison_unlock(&prison0);
316 rsv = NULL;
317 sx_slock(&allprison_lock);
318 TAILQ_FOREACH(pr, &allprison, pr_list) {
319 if (rsv == NULL)
320 rsv = osd_reserve(sem_prison_slot);
321 prison_lock(pr);
322 if (pr->pr_allow & PR_ALLOW_SYSVIPC) {
323 (void)osd_jail_set_reserved(pr, sem_prison_slot, rsv,
324 &prison0);
325 rsv = NULL;
326 }
327 prison_unlock(pr);
328 }
329 if (rsv != NULL)
330 osd_free_reserved(rsv);
331 sx_sunlock(&allprison_lock);
332
333 error = syscall_helper_register(sem_syscalls, SY_THR_STATIC_KLD);
334 if (error != 0)
335 return (error);
336 #ifdef COMPAT_FREEBSD32
337 error = syscall32_helper_register(sem32_syscalls, SY_THR_STATIC_KLD);
338 if (error != 0)
339 return (error);
340 #endif
341 return (0);
342 }
343
344 static int
semunload(void)345 semunload(void)
346 {
347 int i;
348
349 /* XXXKIB */
350 if (semtot != 0)
351 return (EBUSY);
352
353 #ifdef COMPAT_FREEBSD32
354 syscall32_helper_unregister(sem32_syscalls);
355 #endif
356 syscall_helper_unregister(sem_syscalls);
357 EVENTHANDLER_DEREGISTER(process_exit, semexit_tag);
358 if (sem_prison_slot != 0)
359 osd_jail_deregister(sem_prison_slot);
360 #ifdef MAC
361 for (i = 0; i < seminfo.semmni; i++)
362 mac_sysvsem_destroy(&sema[i]);
363 #endif
364 free(sem, M_SEM);
365 free(sema, M_SEM);
366 free(semu, M_SEM);
367 for (i = 0; i < seminfo.semmni; i++)
368 mtx_destroy(&sema_mtx[i]);
369 free(sema_mtx, M_SEM);
370 mtx_destroy(&sem_mtx);
371 mtx_destroy(&sem_undo_mtx);
372 return (0);
373 }
374
375 static int
sysvsem_modload(struct module * module,int cmd,void * arg)376 sysvsem_modload(struct module *module, int cmd, void *arg)
377 {
378 int error = 0;
379
380 switch (cmd) {
381 case MOD_LOAD:
382 error = seminit();
383 break;
384 case MOD_UNLOAD:
385 error = semunload();
386 break;
387 case MOD_SHUTDOWN:
388 break;
389 default:
390 error = EINVAL;
391 break;
392 }
393 return (error);
394 }
395
396 static moduledata_t sysvsem_mod = {
397 "sysvsem",
398 &sysvsem_modload,
399 NULL
400 };
401
402 DECLARE_MODULE(sysvsem, sysvsem_mod, SI_SUB_SYSV_SEM, SI_ORDER_FIRST);
403 MODULE_VERSION(sysvsem, 1);
404
405 /*
406 * Allocate a new sem_undo structure for a process
407 * (returns ptr to structure or NULL if no more room)
408 */
409
410 static struct sem_undo *
semu_alloc(struct thread * td)411 semu_alloc(struct thread *td)
412 {
413 struct sem_undo *suptr;
414
415 SEMUNDO_LOCKASSERT(MA_OWNED);
416 if ((suptr = LIST_FIRST(&semu_free_list)) == NULL)
417 return (NULL);
418 LIST_REMOVE(suptr, un_next);
419 LIST_INSERT_HEAD(&semu_list, suptr, un_next);
420 suptr->un_cnt = 0;
421 suptr->un_proc = td->td_proc;
422 return (suptr);
423 }
424
425 static int
semu_try_free(struct sem_undo * suptr)426 semu_try_free(struct sem_undo *suptr)
427 {
428
429 SEMUNDO_LOCKASSERT(MA_OWNED);
430
431 if (suptr->un_cnt != 0)
432 return (0);
433 LIST_REMOVE(suptr, un_next);
434 LIST_INSERT_HEAD(&semu_free_list, suptr, un_next);
435 return (1);
436 }
437
438 /*
439 * Adjust a particular entry for a particular proc
440 */
441
442 static int
semundo_adjust(struct thread * td,struct sem_undo ** supptr,int semid,int semseq,int semnum,int adjval)443 semundo_adjust(struct thread *td, struct sem_undo **supptr, int semid,
444 int semseq, int semnum, int adjval)
445 {
446 struct proc *p = td->td_proc;
447 struct sem_undo *suptr;
448 struct undo *sunptr;
449 int i;
450
451 SEMUNDO_LOCKASSERT(MA_OWNED);
452 /* Look for and remember the sem_undo if the caller doesn't provide
453 it */
454
455 suptr = *supptr;
456 if (suptr == NULL) {
457 LIST_FOREACH(suptr, &semu_list, un_next) {
458 if (suptr->un_proc == p) {
459 *supptr = suptr;
460 break;
461 }
462 }
463 if (suptr == NULL) {
464 if (adjval == 0)
465 return(0);
466 suptr = semu_alloc(td);
467 if (suptr == NULL)
468 return (ENOSPC);
469 *supptr = suptr;
470 }
471 }
472
473 /*
474 * Look for the requested entry and adjust it (delete if adjval becomes
475 * 0).
476 */
477 sunptr = &suptr->un_ent[0];
478 for (i = 0; i < suptr->un_cnt; i++, sunptr++) {
479 if (sunptr->un_id != semid || sunptr->un_num != semnum)
480 continue;
481 if (adjval != 0) {
482 adjval += sunptr->un_adjval;
483 if (adjval > seminfo.semaem || adjval < -seminfo.semaem)
484 return (ERANGE);
485 }
486 sunptr->un_adjval = adjval;
487 if (sunptr->un_adjval == 0) {
488 suptr->un_cnt--;
489 if (i < suptr->un_cnt)
490 suptr->un_ent[i] =
491 suptr->un_ent[suptr->un_cnt];
492 if (suptr->un_cnt == 0)
493 semu_try_free(suptr);
494 }
495 return (0);
496 }
497
498 /* Didn't find the right entry - create it */
499 if (adjval == 0)
500 return (0);
501 if (adjval > seminfo.semaem || adjval < -seminfo.semaem)
502 return (ERANGE);
503 if (suptr->un_cnt != seminfo.semume) {
504 sunptr = &suptr->un_ent[suptr->un_cnt];
505 suptr->un_cnt++;
506 sunptr->un_adjval = adjval;
507 sunptr->un_id = semid;
508 sunptr->un_num = semnum;
509 sunptr->un_seq = semseq;
510 } else
511 return (EINVAL);
512 return (0);
513 }
514
515 static void
semundo_clear(int semid,int semnum)516 semundo_clear(int semid, int semnum)
517 {
518 struct sem_undo *suptr, *suptr1;
519 struct undo *sunptr;
520 int i;
521
522 SEMUNDO_LOCKASSERT(MA_OWNED);
523 LIST_FOREACH_SAFE(suptr, &semu_list, un_next, suptr1) {
524 sunptr = &suptr->un_ent[0];
525 for (i = 0; i < suptr->un_cnt; i++, sunptr++) {
526 if (sunptr->un_id != semid)
527 continue;
528 if (semnum == -1 || sunptr->un_num == semnum) {
529 suptr->un_cnt--;
530 if (i < suptr->un_cnt) {
531 suptr->un_ent[i] =
532 suptr->un_ent[suptr->un_cnt];
533 continue;
534 }
535 semu_try_free(suptr);
536 }
537 if (semnum != -1)
538 break;
539 }
540 }
541 }
542
543 static int
semvalid(int semid,struct prison * rpr,struct semid_kernel * semakptr)544 semvalid(int semid, struct prison *rpr, struct semid_kernel *semakptr)
545 {
546
547 return ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0 ||
548 semakptr->u.sem_perm.seq != IPCID_TO_SEQ(semid) ||
549 sem_prison_cansee(rpr, semakptr) ? EINVAL : 0);
550 }
551
552 static void
sem_remove(int semidx,struct ucred * cred)553 sem_remove(int semidx, struct ucred *cred)
554 {
555 struct semid_kernel *semakptr;
556 int i;
557
558 KASSERT(semidx >= 0 && semidx < seminfo.semmni,
559 ("semidx out of bounds"));
560 mtx_assert(&sem_mtx, MA_OWNED);
561 semakptr = &sema[semidx];
562 KASSERT(semakptr->u.__sem_base - sem + semakptr->u.sem_nsems <= semtot,
563 ("sem_remove: sema %d corrupted sem pointer %p %p %d %d",
564 semidx, semakptr->u.__sem_base, sem, semakptr->u.sem_nsems,
565 semtot));
566
567 semakptr->u.sem_perm.cuid = cred ? cred->cr_uid : 0;
568 semakptr->u.sem_perm.uid = cred ? cred->cr_uid : 0;
569 semakptr->u.sem_perm.mode = 0;
570 racct_sub_cred(semakptr->cred, RACCT_NSEM, semakptr->u.sem_nsems);
571 crfree(semakptr->cred);
572 semakptr->cred = NULL;
573 SEMUNDO_LOCK();
574 semundo_clear(semidx, -1);
575 SEMUNDO_UNLOCK();
576 #ifdef MAC
577 mac_sysvsem_cleanup(semakptr);
578 #endif
579 wakeup(semakptr);
580 for (i = 0; i < seminfo.semmni; i++) {
581 if ((sema[i].u.sem_perm.mode & SEM_ALLOC) &&
582 sema[i].u.__sem_base > semakptr->u.__sem_base)
583 mtx_lock_flags(&sema_mtx[i], LOP_DUPOK);
584 }
585 for (i = semakptr->u.__sem_base - sem + semakptr->u.sem_nsems;
586 i < semtot; i++)
587 sem[i - semakptr->u.sem_nsems] = sem[i];
588 for (i = 0; i < seminfo.semmni; i++) {
589 if ((sema[i].u.sem_perm.mode & SEM_ALLOC) &&
590 sema[i].u.__sem_base > semakptr->u.__sem_base) {
591 sema[i].u.__sem_base -= semakptr->u.sem_nsems;
592 mtx_unlock(&sema_mtx[i]);
593 }
594 }
595 semtot -= semakptr->u.sem_nsems;
596 }
597
598 static struct prison *
sem_find_prison(struct ucred * cred)599 sem_find_prison(struct ucred *cred)
600 {
601 struct prison *pr, *rpr;
602
603 pr = cred->cr_prison;
604 prison_lock(pr);
605 rpr = osd_jail_get(pr, sem_prison_slot);
606 prison_unlock(pr);
607 return (rpr);
608 }
609
610 static int
sem_prison_cansee(struct prison * rpr,struct semid_kernel * semakptr)611 sem_prison_cansee(struct prison *rpr, struct semid_kernel *semakptr)
612 {
613
614 if (semakptr->cred == NULL ||
615 !(rpr == semakptr->cred->cr_prison ||
616 prison_ischild(rpr, semakptr->cred->cr_prison)))
617 return (EINVAL);
618 return (0);
619 }
620
621 /*
622 * Note that the user-mode half of this passes a union, not a pointer.
623 */
624 #ifndef _SYS_SYSPROTO_H_
625 struct __semctl_args {
626 int semid;
627 int semnum;
628 int cmd;
629 union semun *arg;
630 };
631 #endif
632 int
sys___semctl(struct thread * td,struct __semctl_args * uap)633 sys___semctl(struct thread *td, struct __semctl_args *uap)
634 {
635 struct semid_ds dsbuf;
636 union semun arg, semun;
637 register_t rval;
638 int error;
639
640 switch (uap->cmd) {
641 case SEM_STAT:
642 case IPC_SET:
643 case IPC_STAT:
644 case GETALL:
645 case SETVAL:
646 case SETALL:
647 error = copyin(uap->arg, &arg, sizeof(arg));
648 if (error)
649 return (error);
650 break;
651 }
652
653 switch (uap->cmd) {
654 case SEM_STAT:
655 case IPC_STAT:
656 semun.buf = &dsbuf;
657 break;
658 case IPC_SET:
659 error = copyin(arg.buf, &dsbuf, sizeof(dsbuf));
660 if (error)
661 return (error);
662 semun.buf = &dsbuf;
663 break;
664 case GETALL:
665 case SETALL:
666 semun.array = arg.array;
667 break;
668 case SETVAL:
669 semun.val = arg.val;
670 break;
671 }
672
673 error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
674 &rval);
675 if (error)
676 return (error);
677
678 switch (uap->cmd) {
679 case SEM_STAT:
680 case IPC_STAT:
681 error = copyout(&dsbuf, arg.buf, sizeof(dsbuf));
682 break;
683 }
684
685 if (error == 0)
686 td->td_retval[0] = rval;
687 return (error);
688 }
689
690 int
kern_semctl(struct thread * td,int semid,int semnum,int cmd,union semun * arg,register_t * rval)691 kern_semctl(struct thread *td, int semid, int semnum, int cmd,
692 union semun *arg, register_t *rval)
693 {
694 u_short *array;
695 struct ucred *cred = td->td_ucred;
696 int i, error;
697 struct prison *rpr;
698 struct semid_ds *sbuf;
699 struct semid_kernel *semakptr;
700 struct mtx *sema_mtxp;
701 u_short usval, count;
702 int semidx;
703
704 DPRINTF(("call to semctl(%d, %d, %d, 0x%p)\n",
705 semid, semnum, cmd, arg));
706
707 AUDIT_ARG_SVIPC_CMD(cmd);
708 AUDIT_ARG_SVIPC_ID(semid);
709
710 rpr = sem_find_prison(td->td_ucred);
711 if (rpr == NULL)
712 return (ENOSYS);
713
714 array = NULL;
715
716 switch(cmd) {
717 case SEM_STAT:
718 /*
719 * For this command we assume semid is an array index
720 * rather than an IPC id.
721 */
722 if (semid < 0 || semid >= seminfo.semmni)
723 return (EINVAL);
724 semakptr = &sema[semid];
725 sema_mtxp = &sema_mtx[semid];
726 mtx_lock(sema_mtxp);
727 if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0) {
728 error = EINVAL;
729 goto done2;
730 }
731 if ((error = sem_prison_cansee(rpr, semakptr)))
732 goto done2;
733 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
734 goto done2;
735 #ifdef MAC
736 error = mac_sysvsem_check_semctl(cred, semakptr, cmd);
737 if (error != 0)
738 goto done2;
739 #endif
740 bcopy(&semakptr->u, arg->buf, sizeof(struct semid_ds));
741 if (cred->cr_prison != semakptr->cred->cr_prison)
742 arg->buf->sem_perm.key = IPC_PRIVATE;
743 *rval = IXSEQ_TO_IPCID(semid, semakptr->u.sem_perm);
744 mtx_unlock(sema_mtxp);
745 return (0);
746 }
747
748 semidx = IPCID_TO_IX(semid);
749 if (semidx < 0 || semidx >= seminfo.semmni)
750 return (EINVAL);
751
752 semakptr = &sema[semidx];
753 sema_mtxp = &sema_mtx[semidx];
754 if (cmd == IPC_RMID)
755 mtx_lock(&sem_mtx);
756 mtx_lock(sema_mtxp);
757
758 #ifdef MAC
759 error = mac_sysvsem_check_semctl(cred, semakptr, cmd);
760 if (error != 0)
761 goto done2;
762 #endif
763
764 error = 0;
765 *rval = 0;
766
767 switch (cmd) {
768 case IPC_RMID:
769 if ((error = semvalid(semid, rpr, semakptr)) != 0)
770 goto done2;
771 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_M)))
772 goto done2;
773 sem_remove(semidx, cred);
774 break;
775
776 case IPC_SET:
777 AUDIT_ARG_SVIPC_PERM(&arg->buf->sem_perm);
778 if ((error = semvalid(semid, rpr, semakptr)) != 0)
779 goto done2;
780 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_M)))
781 goto done2;
782 sbuf = arg->buf;
783 semakptr->u.sem_perm.uid = sbuf->sem_perm.uid;
784 semakptr->u.sem_perm.gid = sbuf->sem_perm.gid;
785 semakptr->u.sem_perm.mode = (semakptr->u.sem_perm.mode &
786 ~0777) | (sbuf->sem_perm.mode & 0777);
787 semakptr->u.sem_ctime = time_second;
788 break;
789
790 case IPC_STAT:
791 if ((error = semvalid(semid, rpr, semakptr)) != 0)
792 goto done2;
793 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
794 goto done2;
795 bcopy(&semakptr->u, arg->buf, sizeof(struct semid_ds));
796 if (cred->cr_prison != semakptr->cred->cr_prison)
797 arg->buf->sem_perm.key = IPC_PRIVATE;
798
799 /*
800 * Try to hide the fact that the structure layout is shared by
801 * both the kernel and userland. This pointer is not useful to
802 * userspace.
803 */
804 arg->buf->__sem_base = NULL;
805 break;
806
807 case GETNCNT:
808 if ((error = semvalid(semid, rpr, semakptr)) != 0)
809 goto done2;
810 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
811 goto done2;
812 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) {
813 error = EINVAL;
814 goto done2;
815 }
816 *rval = semakptr->u.__sem_base[semnum].semncnt;
817 break;
818
819 case GETPID:
820 if ((error = semvalid(semid, rpr, semakptr)) != 0)
821 goto done2;
822 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
823 goto done2;
824 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) {
825 error = EINVAL;
826 goto done2;
827 }
828 *rval = semakptr->u.__sem_base[semnum].sempid;
829 break;
830
831 case GETVAL:
832 if ((error = semvalid(semid, rpr, semakptr)) != 0)
833 goto done2;
834 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
835 goto done2;
836 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) {
837 error = EINVAL;
838 goto done2;
839 }
840 *rval = semakptr->u.__sem_base[semnum].semval;
841 break;
842
843 case GETALL:
844 /*
845 * Unfortunately, callers of this function don't know
846 * in advance how many semaphores are in this set.
847 * While we could just allocate the maximum size array
848 * and pass the actual size back to the caller, that
849 * won't work for SETALL since we can't copyin() more
850 * data than the user specified as we may return a
851 * spurious EFAULT.
852 *
853 * Note that the number of semaphores in a set is
854 * fixed for the life of that set. The only way that
855 * the 'count' could change while are blocked in
856 * malloc() is if this semaphore set were destroyed
857 * and a new one created with the same index.
858 * However, semvalid() will catch that due to the
859 * sequence number unless exactly 0x8000 (or a
860 * multiple thereof) semaphore sets for the same index
861 * are created and destroyed while we are in malloc!
862 *
863 */
864 count = semakptr->u.sem_nsems;
865 mtx_unlock(sema_mtxp);
866 array = malloc(sizeof(*array) * count, M_TEMP, M_WAITOK);
867 mtx_lock(sema_mtxp);
868 if ((error = semvalid(semid, rpr, semakptr)) != 0)
869 goto done2;
870 KASSERT(count == semakptr->u.sem_nsems, ("nsems changed"));
871 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
872 goto done2;
873 for (i = 0; i < semakptr->u.sem_nsems; i++)
874 array[i] = semakptr->u.__sem_base[i].semval;
875 mtx_unlock(sema_mtxp);
876 error = copyout(array, arg->array, count * sizeof(*array));
877 mtx_lock(sema_mtxp);
878 break;
879
880 case GETZCNT:
881 if ((error = semvalid(semid, rpr, semakptr)) != 0)
882 goto done2;
883 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_R)))
884 goto done2;
885 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) {
886 error = EINVAL;
887 goto done2;
888 }
889 *rval = semakptr->u.__sem_base[semnum].semzcnt;
890 break;
891
892 case SETVAL:
893 if ((error = semvalid(semid, rpr, semakptr)) != 0)
894 goto done2;
895 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_W)))
896 goto done2;
897 if (semnum < 0 || semnum >= semakptr->u.sem_nsems) {
898 error = EINVAL;
899 goto done2;
900 }
901 if (arg->val < 0 || arg->val > seminfo.semvmx) {
902 error = ERANGE;
903 goto done2;
904 }
905 semakptr->u.__sem_base[semnum].semval = arg->val;
906 SEMUNDO_LOCK();
907 semundo_clear(semidx, semnum);
908 SEMUNDO_UNLOCK();
909 wakeup(semakptr);
910 break;
911
912 case SETALL:
913 /*
914 * See comment on GETALL for why 'count' shouldn't change
915 * and why we require a userland buffer.
916 */
917 count = semakptr->u.sem_nsems;
918 mtx_unlock(sema_mtxp);
919 array = malloc(sizeof(*array) * count, M_TEMP, M_WAITOK);
920 error = copyin(arg->array, array, count * sizeof(*array));
921 mtx_lock(sema_mtxp);
922 if (error)
923 break;
924 if ((error = semvalid(semid, rpr, semakptr)) != 0)
925 goto done2;
926 KASSERT(count == semakptr->u.sem_nsems, ("nsems changed"));
927 if ((error = ipcperm(td, &semakptr->u.sem_perm, IPC_W)))
928 goto done2;
929 for (i = 0; i < semakptr->u.sem_nsems; i++) {
930 usval = array[i];
931 if (usval > seminfo.semvmx) {
932 error = ERANGE;
933 break;
934 }
935 semakptr->u.__sem_base[i].semval = usval;
936 }
937 SEMUNDO_LOCK();
938 semundo_clear(semidx, -1);
939 SEMUNDO_UNLOCK();
940 wakeup(semakptr);
941 break;
942
943 default:
944 error = EINVAL;
945 break;
946 }
947
948 done2:
949 mtx_unlock(sema_mtxp);
950 if (cmd == IPC_RMID)
951 mtx_unlock(&sem_mtx);
952 if (array != NULL)
953 free(array, M_TEMP);
954 return(error);
955 }
956
957 #ifndef _SYS_SYSPROTO_H_
958 struct semget_args {
959 key_t key;
960 int nsems;
961 int semflg;
962 };
963 #endif
964 int
sys_semget(struct thread * td,struct semget_args * uap)965 sys_semget(struct thread *td, struct semget_args *uap)
966 {
967 int semid, error = 0;
968 int key = uap->key;
969 int nsems = uap->nsems;
970 int semflg = uap->semflg;
971 struct ucred *cred = td->td_ucred;
972
973 DPRINTF(("semget(0x%x, %d, 0%o)\n", key, nsems, semflg));
974
975 AUDIT_ARG_VALUE(semflg);
976
977 if (sem_find_prison(cred) == NULL)
978 return (ENOSYS);
979
980 mtx_lock(&sem_mtx);
981 if (key != IPC_PRIVATE) {
982 for (semid = 0; semid < seminfo.semmni; semid++) {
983 if ((sema[semid].u.sem_perm.mode & SEM_ALLOC) &&
984 sema[semid].cred != NULL &&
985 sema[semid].cred->cr_prison == cred->cr_prison &&
986 sema[semid].u.sem_perm.key == key)
987 break;
988 }
989 if (semid < seminfo.semmni) {
990 AUDIT_ARG_SVIPC_ID(semid);
991 DPRINTF(("found public key\n"));
992 if ((semflg & IPC_CREAT) && (semflg & IPC_EXCL)) {
993 DPRINTF(("not exclusive\n"));
994 error = EEXIST;
995 goto done2;
996 }
997 if ((error = ipcperm(td, &sema[semid].u.sem_perm,
998 semflg & 0700))) {
999 goto done2;
1000 }
1001 if (nsems > 0 && sema[semid].u.sem_nsems < nsems) {
1002 DPRINTF(("too small\n"));
1003 error = EINVAL;
1004 goto done2;
1005 }
1006 #ifdef MAC
1007 error = mac_sysvsem_check_semget(cred, &sema[semid]);
1008 if (error != 0)
1009 goto done2;
1010 #endif
1011 goto found;
1012 }
1013 }
1014
1015 DPRINTF(("need to allocate the semid_kernel\n"));
1016 if (key == IPC_PRIVATE || (semflg & IPC_CREAT)) {
1017 if (nsems <= 0 || nsems > seminfo.semmsl) {
1018 DPRINTF(("nsems out of range (0<%d<=%d)\n", nsems,
1019 seminfo.semmsl));
1020 error = EINVAL;
1021 goto done2;
1022 }
1023 if (nsems > seminfo.semmns - semtot) {
1024 DPRINTF((
1025 "not enough semaphores left (need %d, got %d)\n",
1026 nsems, seminfo.semmns - semtot));
1027 error = ENOSPC;
1028 goto done2;
1029 }
1030 for (semid = 0; semid < seminfo.semmni; semid++) {
1031 if ((sema[semid].u.sem_perm.mode & SEM_ALLOC) == 0)
1032 break;
1033 }
1034 if (semid == seminfo.semmni) {
1035 DPRINTF(("no more semid_kernel's available\n"));
1036 error = ENOSPC;
1037 goto done2;
1038 }
1039 #ifdef RACCT
1040 if (racct_enable) {
1041 PROC_LOCK(td->td_proc);
1042 error = racct_add(td->td_proc, RACCT_NSEM, nsems);
1043 PROC_UNLOCK(td->td_proc);
1044 if (error != 0) {
1045 error = ENOSPC;
1046 goto done2;
1047 }
1048 }
1049 #endif
1050 DPRINTF(("semid %d is available\n", semid));
1051 mtx_lock(&sema_mtx[semid]);
1052 KASSERT((sema[semid].u.sem_perm.mode & SEM_ALLOC) == 0,
1053 ("Lost semaphore %d", semid));
1054 sema[semid].u.sem_perm.key = key;
1055 sema[semid].u.sem_perm.cuid = cred->cr_uid;
1056 sema[semid].u.sem_perm.uid = cred->cr_uid;
1057 sema[semid].u.sem_perm.cgid = cred->cr_gid;
1058 sema[semid].u.sem_perm.gid = cred->cr_gid;
1059 sema[semid].u.sem_perm.mode = (semflg & 0777) | SEM_ALLOC;
1060 sema[semid].cred = crhold(cred);
1061 sema[semid].u.sem_perm.seq =
1062 (sema[semid].u.sem_perm.seq + 1) & 0x7fff;
1063 sema[semid].u.sem_nsems = nsems;
1064 sema[semid].u.sem_otime = 0;
1065 sema[semid].u.sem_ctime = time_second;
1066 sema[semid].u.__sem_base = &sem[semtot];
1067 semtot += nsems;
1068 bzero(sema[semid].u.__sem_base,
1069 sizeof(sema[semid].u.__sem_base[0])*nsems);
1070 #ifdef MAC
1071 mac_sysvsem_create(cred, &sema[semid]);
1072 #endif
1073 mtx_unlock(&sema_mtx[semid]);
1074 DPRINTF(("sembase = %p, next = %p\n",
1075 sema[semid].u.__sem_base, &sem[semtot]));
1076 } else {
1077 DPRINTF(("didn't find it and wasn't asked to create it\n"));
1078 error = ENOENT;
1079 goto done2;
1080 }
1081
1082 found:
1083 td->td_retval[0] = IXSEQ_TO_IPCID(semid, sema[semid].u.sem_perm);
1084 done2:
1085 mtx_unlock(&sem_mtx);
1086 return (error);
1087 }
1088
1089 #ifndef _SYS_SYSPROTO_H_
1090 struct semop_args {
1091 int semid;
1092 struct sembuf *sops;
1093 size_t nsops;
1094 };
1095 #endif
1096 int
sys_semop(struct thread * td,struct semop_args * uap)1097 sys_semop(struct thread *td, struct semop_args *uap)
1098 {
1099
1100 return (kern_semop(td, uap->semid, uap->sops, uap->nsops, NULL));
1101 }
1102
1103 int
kern_semop(struct thread * td,int usemid,struct sembuf * usops,size_t nsops,struct timespec * timeout)1104 kern_semop(struct thread *td, int usemid, struct sembuf *usops,
1105 size_t nsops, struct timespec *timeout)
1106 {
1107 #define SMALL_SOPS 8
1108 struct sembuf small_sops[SMALL_SOPS];
1109 int semid;
1110 struct prison *rpr;
1111 struct sembuf *sops;
1112 struct semid_kernel *semakptr;
1113 struct sembuf *sopptr = NULL;
1114 struct sem *semptr = NULL;
1115 struct sem_undo *suptr;
1116 struct mtx *sema_mtxp;
1117 sbintime_t sbt, precision;
1118 size_t i, j, k;
1119 int error;
1120 int do_wakeup, do_undos;
1121 unsigned short seq;
1122
1123 #ifdef SEM_DEBUG
1124 sops = NULL;
1125 #endif
1126 DPRINTF(("call to semop(%d, %p, %u)\n", usemid, usops, nsops));
1127
1128 AUDIT_ARG_SVIPC_ID(usemid);
1129
1130 rpr = sem_find_prison(td->td_ucred);
1131 if (rpr == NULL)
1132 return (ENOSYS);
1133
1134 semid = IPCID_TO_IX(usemid); /* Convert back to zero origin */
1135
1136 if (semid < 0 || semid >= seminfo.semmni)
1137 return (EINVAL);
1138 if (timeout != NULL) {
1139 if (!timespecvalid_interval(timeout))
1140 return (EINVAL);
1141 precision = 0;
1142 if (timespecisset(timeout)) {
1143 if (timeout->tv_sec < INT32_MAX / 2) {
1144 precision = tstosbt(*timeout);
1145 if (TIMESEL(&sbt, precision))
1146 sbt += tc_tick_sbt;
1147 sbt += precision;
1148 precision >>= tc_precexp;
1149 } else
1150 sbt = 0;
1151 } else
1152 sbt = -1;
1153 } else
1154 precision = sbt = 0;
1155
1156 /* Allocate memory for sem_ops */
1157 if (nsops <= SMALL_SOPS)
1158 sops = small_sops;
1159 else if (nsops > seminfo.semopm) {
1160 DPRINTF(("too many sops (max=%d, nsops=%d)\n", seminfo.semopm,
1161 nsops));
1162 return (E2BIG);
1163 } else {
1164 #ifdef RACCT
1165 if (racct_enable) {
1166 PROC_LOCK(td->td_proc);
1167 if (nsops >
1168 racct_get_available(td->td_proc, RACCT_NSEMOP)) {
1169 PROC_UNLOCK(td->td_proc);
1170 return (E2BIG);
1171 }
1172 PROC_UNLOCK(td->td_proc);
1173 }
1174 #endif
1175
1176 sops = malloc(nsops * sizeof(*sops), M_TEMP, M_WAITOK);
1177 }
1178 if ((error = copyin(usops, sops, nsops * sizeof(sops[0]))) != 0) {
1179 DPRINTF(("error = %d from copyin(%p, %p, %d)\n", error,
1180 usops, sops, nsops * sizeof(sops[0])));
1181 if (sops != small_sops)
1182 free(sops, M_TEMP);
1183 return (error);
1184 }
1185
1186 semakptr = &sema[semid];
1187 sema_mtxp = &sema_mtx[semid];
1188 mtx_lock(sema_mtxp);
1189 if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0) {
1190 error = EINVAL;
1191 goto done2;
1192 }
1193 seq = semakptr->u.sem_perm.seq;
1194 if (seq != IPCID_TO_SEQ(usemid)) {
1195 error = EINVAL;
1196 goto done2;
1197 }
1198 if ((error = sem_prison_cansee(rpr, semakptr)) != 0)
1199 goto done2;
1200 /*
1201 * Initial pass through sops to see what permissions are needed.
1202 * Also perform any checks that don't need repeating on each
1203 * attempt to satisfy the request vector.
1204 */
1205 j = 0; /* permission needed */
1206 do_undos = 0;
1207 for (i = 0; i < nsops; i++) {
1208 sopptr = &sops[i];
1209 if (sopptr->sem_num >= semakptr->u.sem_nsems) {
1210 error = EFBIG;
1211 goto done2;
1212 }
1213 if (sopptr->sem_flg & SEM_UNDO && sopptr->sem_op != 0)
1214 do_undos = 1;
1215 j |= (sopptr->sem_op == 0) ? SEM_R : SEM_A;
1216 }
1217
1218 if ((error = ipcperm(td, &semakptr->u.sem_perm, j))) {
1219 DPRINTF(("error = %d from ipaccess\n", error));
1220 goto done2;
1221 }
1222 #ifdef MAC
1223 error = mac_sysvsem_check_semop(td->td_ucred, semakptr, j);
1224 if (error != 0)
1225 goto done2;
1226 #endif
1227
1228 /*
1229 * Loop trying to satisfy the vector of requests.
1230 * If we reach a point where we must wait, any requests already
1231 * performed are rolled back and we go to sleep until some other
1232 * process wakes us up. At this point, we start all over again.
1233 *
1234 * This ensures that from the perspective of other tasks, a set
1235 * of requests is atomic (never partially satisfied).
1236 */
1237 for (;;) {
1238 do_wakeup = 0;
1239 error = 0; /* error return if necessary */
1240
1241 for (i = 0; i < nsops; i++) {
1242 sopptr = &sops[i];
1243 semptr = &semakptr->u.__sem_base[sopptr->sem_num];
1244
1245 DPRINTF((
1246 "semop: semakptr=%p, __sem_base=%p, "
1247 "semptr=%p, sem[%d]=%d : op=%d, flag=%s\n",
1248 semakptr, semakptr->u.__sem_base, semptr,
1249 sopptr->sem_num, semptr->semval, sopptr->sem_op,
1250 (sopptr->sem_flg & IPC_NOWAIT) ?
1251 "nowait" : "wait"));
1252
1253 if (sopptr->sem_op < 0) {
1254 if (semptr->semval + sopptr->sem_op < 0) {
1255 DPRINTF(("semop: can't do it now\n"));
1256 break;
1257 } else {
1258 semptr->semval += sopptr->sem_op;
1259 if (semptr->semval == 0 &&
1260 semptr->semzcnt > 0)
1261 do_wakeup = 1;
1262 }
1263 } else if (sopptr->sem_op == 0) {
1264 if (semptr->semval != 0) {
1265 DPRINTF(("semop: not zero now\n"));
1266 break;
1267 }
1268 } else if (semptr->semval + sopptr->sem_op >
1269 seminfo.semvmx) {
1270 error = ERANGE;
1271 break;
1272 } else {
1273 if (semptr->semncnt > 0)
1274 do_wakeup = 1;
1275 semptr->semval += sopptr->sem_op;
1276 }
1277 }
1278
1279 /*
1280 * Did we get through the entire vector?
1281 */
1282 if (i >= nsops)
1283 goto done;
1284
1285 /*
1286 * No ... rollback anything that we've already done
1287 */
1288 DPRINTF(("semop: rollback 0 through %d\n", i-1));
1289 for (j = 0; j < i; j++)
1290 semakptr->u.__sem_base[sops[j].sem_num].semval -=
1291 sops[j].sem_op;
1292
1293 /* If we detected an error, return it */
1294 if (error != 0)
1295 goto done2;
1296
1297 /*
1298 * If the request that we couldn't satisfy has the
1299 * NOWAIT flag set then return with EAGAIN.
1300 */
1301 if (sopptr->sem_flg & IPC_NOWAIT) {
1302 error = EAGAIN;
1303 goto done2;
1304 }
1305
1306 if (sopptr->sem_op == 0)
1307 semptr->semzcnt++;
1308 else
1309 semptr->semncnt++;
1310
1311 DPRINTF(("semop: good night!\n"));
1312 error = msleep_sbt(semakptr, sema_mtxp, (PZERO - 4) | PCATCH,
1313 "semwait", sbt, precision, C_ABSOLUTE);
1314 DPRINTF(("semop: good morning (error=%d)!\n", error));
1315 /* return code is checked below, after sem[nz]cnt-- */
1316
1317 /*
1318 * Make sure that the semaphore still exists
1319 */
1320 seq = semakptr->u.sem_perm.seq;
1321 if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0 ||
1322 seq != IPCID_TO_SEQ(usemid)) {
1323 error = EIDRM;
1324 goto done2;
1325 }
1326
1327 /*
1328 * Renew the semaphore's pointer after wakeup since
1329 * during msleep __sem_base may have been modified and semptr
1330 * is not valid any more
1331 */
1332 semptr = &semakptr->u.__sem_base[sopptr->sem_num];
1333
1334 /*
1335 * The semaphore is still alive. Readjust the count of
1336 * waiting processes.
1337 */
1338 if (sopptr->sem_op == 0)
1339 semptr->semzcnt--;
1340 else
1341 semptr->semncnt--;
1342
1343 /*
1344 * Is it really morning, or was our sleep interrupted?
1345 * (Delayed check of msleep() return code because we
1346 * need to decrement sem[nz]cnt either way.)
1347 */
1348 if (error != 0) {
1349 if (error == ERESTART)
1350 error = EINTR;
1351 goto done2;
1352 }
1353 DPRINTF(("semop: good morning!\n"));
1354 }
1355
1356 done:
1357 /*
1358 * Process any SEM_UNDO requests.
1359 */
1360 if (do_undos) {
1361 SEMUNDO_LOCK();
1362 suptr = NULL;
1363 for (i = 0; i < nsops; i++) {
1364 /*
1365 * We only need to deal with SEM_UNDO's for non-zero
1366 * op's.
1367 */
1368 int adjval;
1369
1370 if ((sops[i].sem_flg & SEM_UNDO) == 0)
1371 continue;
1372 adjval = sops[i].sem_op;
1373 if (adjval == 0)
1374 continue;
1375 error = semundo_adjust(td, &suptr, semid, seq,
1376 sops[i].sem_num, -adjval);
1377 if (error == 0)
1378 continue;
1379
1380 /*
1381 * Oh-Oh! We ran out of either sem_undo's or undo's.
1382 * Rollback the adjustments to this point and then
1383 * rollback the semaphore ups and down so we can return
1384 * with an error with all structures restored. We
1385 * rollback the undo's in the exact reverse order that
1386 * we applied them. This guarantees that we won't run
1387 * out of space as we roll things back out.
1388 */
1389 for (j = 0; j < i; j++) {
1390 k = i - j - 1;
1391 if ((sops[k].sem_flg & SEM_UNDO) == 0)
1392 continue;
1393 adjval = sops[k].sem_op;
1394 if (adjval == 0)
1395 continue;
1396 if (semundo_adjust(td, &suptr, semid, seq,
1397 sops[k].sem_num, adjval) != 0)
1398 panic("semop - can't undo undos");
1399 }
1400
1401 for (j = 0; j < nsops; j++)
1402 semakptr->u.__sem_base[sops[j].sem_num].semval -=
1403 sops[j].sem_op;
1404
1405 DPRINTF(("error = %d from semundo_adjust\n", error));
1406 SEMUNDO_UNLOCK();
1407 goto done2;
1408 } /* loop through the sops */
1409 SEMUNDO_UNLOCK();
1410 } /* if (do_undos) */
1411
1412 /* We're definitely done - set the sempid's and time */
1413 for (i = 0; i < nsops; i++) {
1414 sopptr = &sops[i];
1415 semptr = &semakptr->u.__sem_base[sopptr->sem_num];
1416 semptr->sempid = td->td_proc->p_pid;
1417 }
1418 semakptr->u.sem_otime = time_second;
1419
1420 /*
1421 * Do a wakeup if any semaphore was up'd whilst something was
1422 * sleeping on it.
1423 */
1424 if (do_wakeup) {
1425 DPRINTF(("semop: doing wakeup\n"));
1426 wakeup(semakptr);
1427 DPRINTF(("semop: back from wakeup\n"));
1428 }
1429 DPRINTF(("semop: done\n"));
1430 td->td_retval[0] = 0;
1431 done2:
1432 mtx_unlock(sema_mtxp);
1433 if (sops != small_sops)
1434 free(sops, M_TEMP);
1435 return (error);
1436 }
1437
1438 /*
1439 * Go through the undo structures for this process and apply the adjustments to
1440 * semaphores.
1441 */
1442 static void
semexit_myhook(void * arg,struct proc * p)1443 semexit_myhook(void *arg, struct proc *p)
1444 {
1445 struct sem_undo *suptr;
1446 struct semid_kernel *semakptr;
1447 struct mtx *sema_mtxp;
1448 int semid, semnum, adjval, ix;
1449 unsigned short seq;
1450
1451 /*
1452 * Go through the chain of undo vectors looking for one
1453 * associated with this process.
1454 */
1455 if (LIST_EMPTY(&semu_list))
1456 return;
1457 SEMUNDO_LOCK();
1458 LIST_FOREACH(suptr, &semu_list, un_next) {
1459 if (suptr->un_proc == p)
1460 break;
1461 }
1462 if (suptr == NULL) {
1463 SEMUNDO_UNLOCK();
1464 return;
1465 }
1466 LIST_REMOVE(suptr, un_next);
1467
1468 DPRINTF(("proc @%p has undo structure with %d entries\n", p,
1469 suptr->un_cnt));
1470
1471 /*
1472 * If there are any active undo elements then process them.
1473 */
1474 if (suptr->un_cnt > 0) {
1475 SEMUNDO_UNLOCK();
1476 for (ix = 0; ix < suptr->un_cnt; ix++) {
1477 semid = suptr->un_ent[ix].un_id;
1478 semnum = suptr->un_ent[ix].un_num;
1479 adjval = suptr->un_ent[ix].un_adjval;
1480 seq = suptr->un_ent[ix].un_seq;
1481 semakptr = &sema[semid];
1482 sema_mtxp = &sema_mtx[semid];
1483
1484 mtx_lock(sema_mtxp);
1485 if ((semakptr->u.sem_perm.mode & SEM_ALLOC) == 0 ||
1486 (semakptr->u.sem_perm.seq != seq)) {
1487 mtx_unlock(sema_mtxp);
1488 continue;
1489 }
1490 if (semnum >= semakptr->u.sem_nsems)
1491 panic("semexit - semnum out of range");
1492
1493 DPRINTF((
1494 "semexit: %p id=%d num=%d(adj=%d) ; sem=%d\n",
1495 suptr->un_proc, suptr->un_ent[ix].un_id,
1496 suptr->un_ent[ix].un_num,
1497 suptr->un_ent[ix].un_adjval,
1498 semakptr->u.__sem_base[semnum].semval));
1499
1500 if (adjval < 0 && semakptr->u.__sem_base[semnum].semval <
1501 -adjval)
1502 semakptr->u.__sem_base[semnum].semval = 0;
1503 else
1504 semakptr->u.__sem_base[semnum].semval += adjval;
1505
1506 wakeup(semakptr);
1507 DPRINTF(("semexit: back from wakeup\n"));
1508 mtx_unlock(sema_mtxp);
1509 }
1510 SEMUNDO_LOCK();
1511 }
1512
1513 /*
1514 * Deallocate the undo vector.
1515 */
1516 DPRINTF(("removing vector\n"));
1517 suptr->un_proc = NULL;
1518 suptr->un_cnt = 0;
1519 LIST_INSERT_HEAD(&semu_free_list, suptr, un_next);
1520 SEMUNDO_UNLOCK();
1521 }
1522
1523 static int
sysctl_sema(SYSCTL_HANDLER_ARGS)1524 sysctl_sema(SYSCTL_HANDLER_ARGS)
1525 {
1526 struct prison *pr, *rpr;
1527 struct semid_kernel tsemak;
1528 #ifdef COMPAT_FREEBSD32
1529 struct semid_kernel32 tsemak32;
1530 #endif
1531 void *outaddr;
1532 size_t outsize;
1533 int error, i;
1534
1535 pr = req->td->td_ucred->cr_prison;
1536 rpr = sem_find_prison(req->td->td_ucred);
1537 error = 0;
1538 for (i = 0; i < seminfo.semmni; i++) {
1539 mtx_lock(&sema_mtx[i]);
1540 if ((sema[i].u.sem_perm.mode & SEM_ALLOC) == 0 ||
1541 rpr == NULL || sem_prison_cansee(rpr, &sema[i]) != 0)
1542 bzero(&tsemak, sizeof(tsemak));
1543 else {
1544 tsemak = sema[i];
1545 if (tsemak.cred->cr_prison != pr)
1546 tsemak.u.sem_perm.key = IPC_PRIVATE;
1547 }
1548 mtx_unlock(&sema_mtx[i]);
1549 #ifdef COMPAT_FREEBSD32
1550 if (SV_CURPROC_FLAG(SV_ILP32)) {
1551 bzero(&tsemak32, sizeof(tsemak32));
1552 freebsd32_ipcperm_out(&tsemak.u.sem_perm,
1553 &tsemak32.u.sem_perm);
1554 /* Don't copy u.__sem_base */
1555 CP(tsemak, tsemak32, u.sem_nsems);
1556 CP(tsemak, tsemak32, u.sem_otime);
1557 CP(tsemak, tsemak32, u.sem_ctime);
1558 /* Don't copy label or cred */
1559 outaddr = &tsemak32;
1560 outsize = sizeof(tsemak32);
1561 } else
1562 #endif
1563 {
1564 tsemak.u.__sem_base = NULL;
1565 tsemak.label = NULL;
1566 tsemak.cred = NULL;
1567 outaddr = &tsemak;
1568 outsize = sizeof(tsemak);
1569 }
1570 error = SYSCTL_OUT(req, outaddr, outsize);
1571 if (error != 0)
1572 break;
1573 }
1574 return (error);
1575 }
1576
1577 int
kern_get_sema(struct thread * td,struct semid_kernel ** res,size_t * sz)1578 kern_get_sema(struct thread *td, struct semid_kernel **res, size_t *sz)
1579 {
1580 struct prison *pr, *rpr;
1581 struct semid_kernel *psemak;
1582 int i, mi;
1583
1584 *sz = mi = seminfo.semmni;
1585 if (res == NULL)
1586 return (0);
1587
1588 pr = td->td_ucred->cr_prison;
1589 rpr = sem_find_prison(td->td_ucred);
1590 *res = malloc(sizeof(struct semid_kernel) * mi, M_TEMP, M_WAITOK);
1591 for (i = 0; i < mi; i++) {
1592 psemak = &(*res)[i];
1593 mtx_lock(&sema_mtx[i]);
1594 if ((sema[i].u.sem_perm.mode & SEM_ALLOC) == 0 ||
1595 rpr == NULL || sem_prison_cansee(rpr, &sema[i]) != 0)
1596 bzero(psemak, sizeof(*psemak));
1597 else {
1598 *psemak = sema[i];
1599 if (psemak->cred->cr_prison != pr)
1600 psemak->u.sem_perm.key = IPC_PRIVATE;
1601 }
1602 mtx_unlock(&sema_mtx[i]);
1603 psemak->u.__sem_base = NULL;
1604 psemak->label = NULL;
1605 psemak->cred = NULL;
1606 }
1607 return (0);
1608 }
1609
1610 static int
sem_prison_check(void * obj,void * data)1611 sem_prison_check(void *obj, void *data)
1612 {
1613 struct prison *pr = obj;
1614 struct prison *prpr;
1615 struct vfsoptlist *opts = data;
1616 int error, jsys;
1617
1618 /*
1619 * sysvsem is a jailsys integer.
1620 * It must be "disable" if the parent jail is disabled.
1621 */
1622 error = vfs_copyopt(opts, "sysvsem", &jsys, sizeof(jsys));
1623 if (error != ENOENT) {
1624 if (error != 0)
1625 return (error);
1626 switch (jsys) {
1627 case JAIL_SYS_DISABLE:
1628 break;
1629 case JAIL_SYS_NEW:
1630 case JAIL_SYS_INHERIT:
1631 prison_lock(pr->pr_parent);
1632 prpr = osd_jail_get(pr->pr_parent, sem_prison_slot);
1633 prison_unlock(pr->pr_parent);
1634 if (prpr == NULL)
1635 return (EPERM);
1636 break;
1637 default:
1638 return (EINVAL);
1639 }
1640 }
1641
1642 return (0);
1643 }
1644
1645 static int
sem_prison_set(void * obj,void * data)1646 sem_prison_set(void *obj, void *data)
1647 {
1648 struct prison *pr = obj;
1649 struct prison *tpr, *orpr, *nrpr, *trpr;
1650 struct vfsoptlist *opts = data;
1651 void *rsv;
1652 int jsys, descend;
1653
1654 /*
1655 * sysvsem controls which jail is the root of the associated sems (this
1656 * jail or same as the parent), or if the feature is available at all.
1657 */
1658 if (vfs_copyopt(opts, "sysvsem", &jsys, sizeof(jsys)) == ENOENT)
1659 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
1660 ? JAIL_SYS_INHERIT
1661 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
1662 ? JAIL_SYS_DISABLE
1663 : -1;
1664 if (jsys == JAIL_SYS_DISABLE) {
1665 prison_lock(pr);
1666 orpr = osd_jail_get(pr, sem_prison_slot);
1667 if (orpr != NULL)
1668 osd_jail_del(pr, sem_prison_slot);
1669 prison_unlock(pr);
1670 if (orpr != NULL) {
1671 if (orpr == pr)
1672 sem_prison_cleanup(pr);
1673 /* Disable all child jails as well. */
1674 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1675 prison_lock(tpr);
1676 trpr = osd_jail_get(tpr, sem_prison_slot);
1677 if (trpr != NULL) {
1678 osd_jail_del(tpr, sem_prison_slot);
1679 prison_unlock(tpr);
1680 if (trpr == tpr)
1681 sem_prison_cleanup(tpr);
1682 } else {
1683 prison_unlock(tpr);
1684 descend = 0;
1685 }
1686 }
1687 }
1688 } else if (jsys != -1) {
1689 if (jsys == JAIL_SYS_NEW)
1690 nrpr = pr;
1691 else {
1692 prison_lock(pr->pr_parent);
1693 nrpr = osd_jail_get(pr->pr_parent, sem_prison_slot);
1694 prison_unlock(pr->pr_parent);
1695 }
1696 rsv = osd_reserve(sem_prison_slot);
1697 prison_lock(pr);
1698 orpr = osd_jail_get(pr, sem_prison_slot);
1699 if (orpr != nrpr)
1700 (void)osd_jail_set_reserved(pr, sem_prison_slot, rsv,
1701 nrpr);
1702 else
1703 osd_free_reserved(rsv);
1704 prison_unlock(pr);
1705 if (orpr != nrpr) {
1706 if (orpr == pr)
1707 sem_prison_cleanup(pr);
1708 if (orpr != NULL) {
1709 /* Change child jails matching the old root, */
1710 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1711 prison_lock(tpr);
1712 trpr = osd_jail_get(tpr,
1713 sem_prison_slot);
1714 if (trpr == orpr) {
1715 (void)osd_jail_set(tpr,
1716 sem_prison_slot, nrpr);
1717 prison_unlock(tpr);
1718 if (trpr == tpr)
1719 sem_prison_cleanup(tpr);
1720 } else {
1721 prison_unlock(tpr);
1722 descend = 0;
1723 }
1724 }
1725 }
1726 }
1727 }
1728
1729 return (0);
1730 }
1731
1732 static int
sem_prison_get(void * obj,void * data)1733 sem_prison_get(void *obj, void *data)
1734 {
1735 struct prison *pr = obj;
1736 struct prison *rpr;
1737 struct vfsoptlist *opts = data;
1738 int error, jsys;
1739
1740 /* Set sysvsem based on the jail's root prison. */
1741 prison_lock(pr);
1742 rpr = osd_jail_get(pr, sem_prison_slot);
1743 prison_unlock(pr);
1744 jsys = rpr == NULL ? JAIL_SYS_DISABLE
1745 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
1746 error = vfs_setopt(opts, "sysvsem", &jsys, sizeof(jsys));
1747 if (error == ENOENT)
1748 error = 0;
1749 return (error);
1750 }
1751
1752 static int
sem_prison_remove(void * obj,void * data __unused)1753 sem_prison_remove(void *obj, void *data __unused)
1754 {
1755 struct prison *pr = obj;
1756 struct prison *rpr;
1757
1758 prison_lock(pr);
1759 rpr = osd_jail_get(pr, sem_prison_slot);
1760 prison_unlock(pr);
1761 if (rpr == pr)
1762 sem_prison_cleanup(pr);
1763 return (0);
1764 }
1765
1766 static void
sem_prison_cleanup(struct prison * pr)1767 sem_prison_cleanup(struct prison *pr)
1768 {
1769 int i;
1770
1771 /* Remove any sems that belong to this jail. */
1772 mtx_lock(&sem_mtx);
1773 for (i = 0; i < seminfo.semmni; i++) {
1774 if ((sema[i].u.sem_perm.mode & SEM_ALLOC) &&
1775 sema[i].cred != NULL && sema[i].cred->cr_prison == pr) {
1776 mtx_lock(&sema_mtx[i]);
1777 sem_remove(i, NULL);
1778 mtx_unlock(&sema_mtx[i]);
1779 }
1780 }
1781 mtx_unlock(&sem_mtx);
1782 }
1783
1784 SYSCTL_JAIL_PARAM_SYS_NODE(sysvsem, CTLFLAG_RW, "SYSV semaphores");
1785
1786 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1787 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1788
1789 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1790 static sy_call_t *semcalls[] = {
1791 (sy_call_t *)freebsd7___semctl, (sy_call_t *)sys_semget,
1792 (sy_call_t *)sys_semop
1793 };
1794
1795 /*
1796 * Entry point for all SEM calls.
1797 */
1798 int
sys_semsys(struct thread * td,struct semsys_args * uap)1799 sys_semsys(struct thread *td, struct semsys_args *uap)
1800 {
1801 int error;
1802
1803 AUDIT_ARG_SVIPC_WHICH(uap->which);
1804 if (uap->which < 0 || uap->which >= nitems(semcalls))
1805 return (EINVAL);
1806 error = (*semcalls[uap->which])(td, &uap->a2);
1807 return (error);
1808 }
1809
1810 #ifndef _SYS_SYSPROTO_H_
1811 struct freebsd7___semctl_args {
1812 int semid;
1813 int semnum;
1814 int cmd;
1815 union semun_old *arg;
1816 };
1817 #endif
1818 int
freebsd7___semctl(struct thread * td,struct freebsd7___semctl_args * uap)1819 freebsd7___semctl(struct thread *td, struct freebsd7___semctl_args *uap)
1820 {
1821 struct semid_ds_old dsold;
1822 struct semid_ds dsbuf;
1823 union semun_old arg;
1824 union semun semun;
1825 register_t rval;
1826 int error;
1827
1828 switch (uap->cmd) {
1829 case SEM_STAT:
1830 case IPC_SET:
1831 case IPC_STAT:
1832 case GETALL:
1833 case SETVAL:
1834 case SETALL:
1835 error = copyin(uap->arg, &arg, sizeof(arg));
1836 if (error)
1837 return (error);
1838 break;
1839 }
1840
1841 switch (uap->cmd) {
1842 case SEM_STAT:
1843 case IPC_STAT:
1844 semun.buf = &dsbuf;
1845 break;
1846 case IPC_SET:
1847 error = copyin(arg.buf, &dsold, sizeof(dsold));
1848 if (error)
1849 return (error);
1850 ipcperm_old2new(&dsold.sem_perm, &dsbuf.sem_perm);
1851 CP(dsold, dsbuf, __sem_base);
1852 CP(dsold, dsbuf, sem_nsems);
1853 CP(dsold, dsbuf, sem_otime);
1854 CP(dsold, dsbuf, sem_ctime);
1855 semun.buf = &dsbuf;
1856 break;
1857 case GETALL:
1858 case SETALL:
1859 semun.array = arg.array;
1860 break;
1861 case SETVAL:
1862 semun.val = arg.val;
1863 break;
1864 }
1865
1866 error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
1867 &rval);
1868 if (error)
1869 return (error);
1870
1871 switch (uap->cmd) {
1872 case SEM_STAT:
1873 case IPC_STAT:
1874 bzero(&dsold, sizeof(dsold));
1875 ipcperm_new2old(&dsbuf.sem_perm, &dsold.sem_perm);
1876 CP(dsbuf, dsold, __sem_base);
1877 CP(dsbuf, dsold, sem_nsems);
1878 CP(dsbuf, dsold, sem_otime);
1879 CP(dsbuf, dsold, sem_ctime);
1880 error = copyout(&dsold, arg.buf, sizeof(dsold));
1881 break;
1882 }
1883
1884 if (error == 0)
1885 td->td_retval[0] = rval;
1886 return (error);
1887 }
1888
1889 #endif /* COMPAT_FREEBSD{4,5,6,7} */
1890
1891 #ifdef COMPAT_FREEBSD32
1892
1893 int
freebsd32_semsys(struct thread * td,struct freebsd32_semsys_args * uap)1894 freebsd32_semsys(struct thread *td, struct freebsd32_semsys_args *uap)
1895 {
1896
1897 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1898 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1899 AUDIT_ARG_SVIPC_WHICH(uap->which);
1900 switch (uap->which) {
1901 case 0:
1902 return (freebsd7_freebsd32___semctl(td,
1903 (struct freebsd7_freebsd32___semctl_args *)&uap->a2));
1904 default:
1905 return (sys_semsys(td, (struct semsys_args *)uap));
1906 }
1907 #else
1908 return (nosys(td, NULL));
1909 #endif
1910 }
1911
1912 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1913 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1914 int
freebsd7_freebsd32___semctl(struct thread * td,struct freebsd7_freebsd32___semctl_args * uap)1915 freebsd7_freebsd32___semctl(struct thread *td,
1916 struct freebsd7_freebsd32___semctl_args *uap)
1917 {
1918 struct semid_ds_old32 dsbuf32;
1919 struct semid_ds dsbuf;
1920 union semun semun;
1921 union semun_old32 arg;
1922 register_t rval;
1923 int error;
1924
1925 switch (uap->cmd) {
1926 case SEM_STAT:
1927 case IPC_SET:
1928 case IPC_STAT:
1929 case GETALL:
1930 case SETVAL:
1931 case SETALL:
1932 error = copyin(uap->arg, &arg, sizeof(arg));
1933 if (error)
1934 return (error);
1935 break;
1936 }
1937
1938 switch (uap->cmd) {
1939 case SEM_STAT:
1940 case IPC_STAT:
1941 semun.buf = &dsbuf;
1942 break;
1943 case IPC_SET:
1944 error = copyin(PTRIN(arg.buf), &dsbuf32, sizeof(dsbuf32));
1945 if (error)
1946 return (error);
1947 freebsd32_ipcperm_old_in(&dsbuf32.sem_perm, &dsbuf.sem_perm);
1948 PTRIN_CP(dsbuf32, dsbuf, __sem_base);
1949 CP(dsbuf32, dsbuf, sem_nsems);
1950 CP(dsbuf32, dsbuf, sem_otime);
1951 CP(dsbuf32, dsbuf, sem_ctime);
1952 semun.buf = &dsbuf;
1953 break;
1954 case GETALL:
1955 case SETALL:
1956 semun.array = PTRIN(arg.array);
1957 break;
1958 case SETVAL:
1959 semun.val = arg.val;
1960 break;
1961 }
1962
1963 error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
1964 &rval);
1965 if (error)
1966 return (error);
1967
1968 switch (uap->cmd) {
1969 case SEM_STAT:
1970 case IPC_STAT:
1971 bzero(&dsbuf32, sizeof(dsbuf32));
1972 freebsd32_ipcperm_old_out(&dsbuf.sem_perm, &dsbuf32.sem_perm);
1973 PTROUT_CP(dsbuf, dsbuf32, __sem_base);
1974 CP(dsbuf, dsbuf32, sem_nsems);
1975 CP(dsbuf, dsbuf32, sem_otime);
1976 CP(dsbuf, dsbuf32, sem_ctime);
1977 error = copyout(&dsbuf32, PTRIN(arg.buf), sizeof(dsbuf32));
1978 break;
1979 }
1980
1981 if (error == 0)
1982 td->td_retval[0] = rval;
1983 return (error);
1984 }
1985 #endif
1986
1987 int
freebsd32___semctl(struct thread * td,struct freebsd32___semctl_args * uap)1988 freebsd32___semctl(struct thread *td, struct freebsd32___semctl_args *uap)
1989 {
1990 struct semid_ds32 dsbuf32;
1991 struct semid_ds dsbuf;
1992 union semun semun;
1993 union semun32 arg;
1994 register_t rval;
1995 int error;
1996
1997 switch (uap->cmd) {
1998 case SEM_STAT:
1999 case IPC_SET:
2000 case IPC_STAT:
2001 case GETALL:
2002 case SETVAL:
2003 case SETALL:
2004 error = copyin(uap->arg, &arg, sizeof(arg));
2005 if (error)
2006 return (error);
2007 break;
2008 }
2009
2010 switch (uap->cmd) {
2011 case SEM_STAT:
2012 case IPC_STAT:
2013 semun.buf = &dsbuf;
2014 break;
2015 case IPC_SET:
2016 error = copyin(PTRIN(arg.buf), &dsbuf32, sizeof(dsbuf32));
2017 if (error)
2018 return (error);
2019 freebsd32_ipcperm_in(&dsbuf32.sem_perm, &dsbuf.sem_perm);
2020 PTRIN_CP(dsbuf32, dsbuf, __sem_base);
2021 CP(dsbuf32, dsbuf, sem_nsems);
2022 CP(dsbuf32, dsbuf, sem_otime);
2023 CP(dsbuf32, dsbuf, sem_ctime);
2024 semun.buf = &dsbuf;
2025 break;
2026 case GETALL:
2027 case SETALL:
2028 semun.array = PTRIN(arg.array);
2029 break;
2030 case SETVAL:
2031 semun.val = arg.val;
2032 break;
2033 }
2034
2035 error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
2036 &rval);
2037 if (error)
2038 return (error);
2039
2040 switch (uap->cmd) {
2041 case SEM_STAT:
2042 case IPC_STAT:
2043 bzero(&dsbuf32, sizeof(dsbuf32));
2044 freebsd32_ipcperm_out(&dsbuf.sem_perm, &dsbuf32.sem_perm);
2045 PTROUT_CP(dsbuf, dsbuf32, __sem_base);
2046 CP(dsbuf, dsbuf32, sem_nsems);
2047 CP(dsbuf, dsbuf32, sem_otime);
2048 CP(dsbuf, dsbuf32, sem_ctime);
2049 error = copyout(&dsbuf32, PTRIN(arg.buf), sizeof(dsbuf32));
2050 break;
2051 }
2052
2053 if (error == 0)
2054 td->td_retval[0] = rval;
2055 return (error);
2056 }
2057
2058 #endif /* COMPAT_FREEBSD32 */
2059