xref: /freebsd/sys/kern/sysv_sem.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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
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
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
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 *
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
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
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
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
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
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 *
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
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
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
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
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
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
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
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
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 static int
1578 sem_prison_check(void *obj, void *data)
1579 {
1580 	struct prison *pr = obj;
1581 	struct prison *prpr;
1582 	struct vfsoptlist *opts = data;
1583 	int error, jsys;
1584 
1585 	/*
1586 	 * sysvsem is a jailsys integer.
1587 	 * It must be "disable" if the parent jail is disabled.
1588 	 */
1589 	error = vfs_copyopt(opts, "sysvsem", &jsys, sizeof(jsys));
1590 	if (error != ENOENT) {
1591 		if (error != 0)
1592 			return (error);
1593 		switch (jsys) {
1594 		case JAIL_SYS_DISABLE:
1595 			break;
1596 		case JAIL_SYS_NEW:
1597 		case JAIL_SYS_INHERIT:
1598 			prison_lock(pr->pr_parent);
1599 			prpr = osd_jail_get(pr->pr_parent, sem_prison_slot);
1600 			prison_unlock(pr->pr_parent);
1601 			if (prpr == NULL)
1602 				return (EPERM);
1603 			break;
1604 		default:
1605 			return (EINVAL);
1606 		}
1607 	}
1608 
1609 	return (0);
1610 }
1611 
1612 static int
1613 sem_prison_set(void *obj, void *data)
1614 {
1615 	struct prison *pr = obj;
1616 	struct prison *tpr, *orpr, *nrpr, *trpr;
1617 	struct vfsoptlist *opts = data;
1618 	void *rsv;
1619 	int jsys, descend;
1620 
1621 	/*
1622 	 * sysvsem controls which jail is the root of the associated sems (this
1623 	 * jail or same as the parent), or if the feature is available at all.
1624 	 */
1625 	if (vfs_copyopt(opts, "sysvsem", &jsys, sizeof(jsys)) == ENOENT)
1626 		jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
1627 		    ? JAIL_SYS_INHERIT
1628 		    : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
1629 		    ? JAIL_SYS_DISABLE
1630 		    : -1;
1631 	if (jsys == JAIL_SYS_DISABLE) {
1632 		prison_lock(pr);
1633 		orpr = osd_jail_get(pr, sem_prison_slot);
1634 		if (orpr != NULL)
1635 			osd_jail_del(pr, sem_prison_slot);
1636 		prison_unlock(pr);
1637 		if (orpr != NULL) {
1638 			if (orpr == pr)
1639 				sem_prison_cleanup(pr);
1640 			/* Disable all child jails as well. */
1641 			FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1642 				prison_lock(tpr);
1643 				trpr = osd_jail_get(tpr, sem_prison_slot);
1644 				if (trpr != NULL) {
1645 					osd_jail_del(tpr, sem_prison_slot);
1646 					prison_unlock(tpr);
1647 					if (trpr == tpr)
1648 						sem_prison_cleanup(tpr);
1649 				} else {
1650 					prison_unlock(tpr);
1651 					descend = 0;
1652 				}
1653 			}
1654 		}
1655 	} else if (jsys != -1) {
1656 		if (jsys == JAIL_SYS_NEW)
1657 			nrpr = pr;
1658 		else {
1659 			prison_lock(pr->pr_parent);
1660 			nrpr = osd_jail_get(pr->pr_parent, sem_prison_slot);
1661 			prison_unlock(pr->pr_parent);
1662 		}
1663 		rsv = osd_reserve(sem_prison_slot);
1664 		prison_lock(pr);
1665 		orpr = osd_jail_get(pr, sem_prison_slot);
1666 		if (orpr != nrpr)
1667 			(void)osd_jail_set_reserved(pr, sem_prison_slot, rsv,
1668 			    nrpr);
1669 		else
1670 			osd_free_reserved(rsv);
1671 		prison_unlock(pr);
1672 		if (orpr != nrpr) {
1673 			if (orpr == pr)
1674 				sem_prison_cleanup(pr);
1675 			if (orpr != NULL) {
1676 				/* Change child jails matching the old root, */
1677 				FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1678 					prison_lock(tpr);
1679 					trpr = osd_jail_get(tpr,
1680 					    sem_prison_slot);
1681 					if (trpr == orpr) {
1682 						(void)osd_jail_set(tpr,
1683 						    sem_prison_slot, nrpr);
1684 						prison_unlock(tpr);
1685 						if (trpr == tpr)
1686 							sem_prison_cleanup(tpr);
1687 					} else {
1688 						prison_unlock(tpr);
1689 						descend = 0;
1690 					}
1691 				}
1692 			}
1693 		}
1694 	}
1695 
1696 	return (0);
1697 }
1698 
1699 static int
1700 sem_prison_get(void *obj, void *data)
1701 {
1702 	struct prison *pr = obj;
1703 	struct prison *rpr;
1704 	struct vfsoptlist *opts = data;
1705 	int error, jsys;
1706 
1707 	/* Set sysvsem based on the jail's root prison. */
1708 	prison_lock(pr);
1709 	rpr = osd_jail_get(pr, sem_prison_slot);
1710 	prison_unlock(pr);
1711 	jsys = rpr == NULL ? JAIL_SYS_DISABLE
1712 	    : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
1713 	error = vfs_setopt(opts, "sysvsem", &jsys, sizeof(jsys));
1714 	if (error == ENOENT)
1715 		error = 0;
1716 	return (error);
1717 }
1718 
1719 static int
1720 sem_prison_remove(void *obj, void *data __unused)
1721 {
1722 	struct prison *pr = obj;
1723 	struct prison *rpr;
1724 
1725 	prison_lock(pr);
1726 	rpr = osd_jail_get(pr, sem_prison_slot);
1727 	prison_unlock(pr);
1728 	if (rpr == pr)
1729 		sem_prison_cleanup(pr);
1730 	return (0);
1731 }
1732 
1733 static void
1734 sem_prison_cleanup(struct prison *pr)
1735 {
1736 	int i;
1737 
1738 	/* Remove any sems that belong to this jail. */
1739 	mtx_lock(&sem_mtx);
1740 	for (i = 0; i < seminfo.semmni; i++) {
1741 		if ((sema[i].u.sem_perm.mode & SEM_ALLOC) &&
1742 		    sema[i].cred != NULL && sema[i].cred->cr_prison == pr) {
1743 			mtx_lock(&sema_mtx[i]);
1744 			sem_remove(i, NULL);
1745 			mtx_unlock(&sema_mtx[i]);
1746 		}
1747 	}
1748 	mtx_unlock(&sem_mtx);
1749 }
1750 
1751 SYSCTL_JAIL_PARAM_SYS_NODE(sysvsem, CTLFLAG_RW, "SYSV semaphores");
1752 
1753 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1754     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1755 
1756 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1757 static sy_call_t *semcalls[] = {
1758 	(sy_call_t *)freebsd7___semctl, (sy_call_t *)sys_semget,
1759 	(sy_call_t *)sys_semop
1760 };
1761 
1762 /*
1763  * Entry point for all SEM calls.
1764  */
1765 int
1766 sys_semsys(struct thread *td, struct semsys_args *uap)
1767 {
1768 	int error;
1769 
1770 	AUDIT_ARG_SVIPC_WHICH(uap->which);
1771 	if (uap->which < 0 || uap->which >= nitems(semcalls))
1772 		return (EINVAL);
1773 	error = (*semcalls[uap->which])(td, &uap->a2);
1774 	return (error);
1775 }
1776 
1777 #ifndef _SYS_SYSPROTO_H_
1778 struct freebsd7___semctl_args {
1779 	int	semid;
1780 	int	semnum;
1781 	int	cmd;
1782 	union	semun_old *arg;
1783 };
1784 #endif
1785 int
1786 freebsd7___semctl(struct thread *td, struct freebsd7___semctl_args *uap)
1787 {
1788 	struct semid_ds_old dsold;
1789 	struct semid_ds dsbuf;
1790 	union semun_old arg;
1791 	union semun semun;
1792 	register_t rval;
1793 	int error;
1794 
1795 	switch (uap->cmd) {
1796 	case SEM_STAT:
1797 	case IPC_SET:
1798 	case IPC_STAT:
1799 	case GETALL:
1800 	case SETVAL:
1801 	case SETALL:
1802 		error = copyin(uap->arg, &arg, sizeof(arg));
1803 		if (error)
1804 			return (error);
1805 		break;
1806 	}
1807 
1808 	switch (uap->cmd) {
1809 	case SEM_STAT:
1810 	case IPC_STAT:
1811 		semun.buf = &dsbuf;
1812 		break;
1813 	case IPC_SET:
1814 		error = copyin(arg.buf, &dsold, sizeof(dsold));
1815 		if (error)
1816 			return (error);
1817 		ipcperm_old2new(&dsold.sem_perm, &dsbuf.sem_perm);
1818 		CP(dsold, dsbuf, __sem_base);
1819 		CP(dsold, dsbuf, sem_nsems);
1820 		CP(dsold, dsbuf, sem_otime);
1821 		CP(dsold, dsbuf, sem_ctime);
1822 		semun.buf = &dsbuf;
1823 		break;
1824 	case GETALL:
1825 	case SETALL:
1826 		semun.array = arg.array;
1827 		break;
1828 	case SETVAL:
1829 		semun.val = arg.val;
1830 		break;
1831 	}
1832 
1833 	error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
1834 	    &rval);
1835 	if (error)
1836 		return (error);
1837 
1838 	switch (uap->cmd) {
1839 	case SEM_STAT:
1840 	case IPC_STAT:
1841 		bzero(&dsold, sizeof(dsold));
1842 		ipcperm_new2old(&dsbuf.sem_perm, &dsold.sem_perm);
1843 		CP(dsbuf, dsold, __sem_base);
1844 		CP(dsbuf, dsold, sem_nsems);
1845 		CP(dsbuf, dsold, sem_otime);
1846 		CP(dsbuf, dsold, sem_ctime);
1847 		error = copyout(&dsold, arg.buf, sizeof(dsold));
1848 		break;
1849 	}
1850 
1851 	if (error == 0)
1852 		td->td_retval[0] = rval;
1853 	return (error);
1854 }
1855 
1856 #endif /* COMPAT_FREEBSD{4,5,6,7} */
1857 
1858 #ifdef COMPAT_FREEBSD32
1859 
1860 int
1861 freebsd32_semsys(struct thread *td, struct freebsd32_semsys_args *uap)
1862 {
1863 
1864 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1865     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1866 	AUDIT_ARG_SVIPC_WHICH(uap->which);
1867 	switch (uap->which) {
1868 	case 0:
1869 		return (freebsd7_freebsd32___semctl(td,
1870 		    (struct freebsd7_freebsd32___semctl_args *)&uap->a2));
1871 	default:
1872 		return (sys_semsys(td, (struct semsys_args *)uap));
1873 	}
1874 #else
1875 	return (nosys(td, NULL));
1876 #endif
1877 }
1878 
1879 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1880     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1881 int
1882 freebsd7_freebsd32___semctl(struct thread *td,
1883     struct freebsd7_freebsd32___semctl_args *uap)
1884 {
1885 	struct semid_ds_old32 dsbuf32;
1886 	struct semid_ds dsbuf;
1887 	union semun semun;
1888 	union semun_old32 arg;
1889 	register_t rval;
1890 	int error;
1891 
1892 	switch (uap->cmd) {
1893 	case SEM_STAT:
1894 	case IPC_SET:
1895 	case IPC_STAT:
1896 	case GETALL:
1897 	case SETVAL:
1898 	case SETALL:
1899 		error = copyin(uap->arg, &arg, sizeof(arg));
1900 		if (error)
1901 			return (error);
1902 		break;
1903 	}
1904 
1905 	switch (uap->cmd) {
1906 	case SEM_STAT:
1907 	case IPC_STAT:
1908 		semun.buf = &dsbuf;
1909 		break;
1910 	case IPC_SET:
1911 		error = copyin(PTRIN(arg.buf), &dsbuf32, sizeof(dsbuf32));
1912 		if (error)
1913 			return (error);
1914 		freebsd32_ipcperm_old_in(&dsbuf32.sem_perm, &dsbuf.sem_perm);
1915 		PTRIN_CP(dsbuf32, dsbuf, __sem_base);
1916 		CP(dsbuf32, dsbuf, sem_nsems);
1917 		CP(dsbuf32, dsbuf, sem_otime);
1918 		CP(dsbuf32, dsbuf, sem_ctime);
1919 		semun.buf = &dsbuf;
1920 		break;
1921 	case GETALL:
1922 	case SETALL:
1923 		semun.array = PTRIN(arg.array);
1924 		break;
1925 	case SETVAL:
1926 		semun.val = arg.val;
1927 		break;
1928 	}
1929 
1930 	error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
1931 	    &rval);
1932 	if (error)
1933 		return (error);
1934 
1935 	switch (uap->cmd) {
1936 	case SEM_STAT:
1937 	case IPC_STAT:
1938 		bzero(&dsbuf32, sizeof(dsbuf32));
1939 		freebsd32_ipcperm_old_out(&dsbuf.sem_perm, &dsbuf32.sem_perm);
1940 		PTROUT_CP(dsbuf, dsbuf32, __sem_base);
1941 		CP(dsbuf, dsbuf32, sem_nsems);
1942 		CP(dsbuf, dsbuf32, sem_otime);
1943 		CP(dsbuf, dsbuf32, sem_ctime);
1944 		error = copyout(&dsbuf32, PTRIN(arg.buf), sizeof(dsbuf32));
1945 		break;
1946 	}
1947 
1948 	if (error == 0)
1949 		td->td_retval[0] = rval;
1950 	return (error);
1951 }
1952 #endif
1953 
1954 int
1955 freebsd32___semctl(struct thread *td, struct freebsd32___semctl_args *uap)
1956 {
1957 	struct semid_ds32 dsbuf32;
1958 	struct semid_ds dsbuf;
1959 	union semun semun;
1960 	union semun32 arg;
1961 	register_t rval;
1962 	int error;
1963 
1964 	switch (uap->cmd) {
1965 	case SEM_STAT:
1966 	case IPC_SET:
1967 	case IPC_STAT:
1968 	case GETALL:
1969 	case SETVAL:
1970 	case SETALL:
1971 		error = copyin(uap->arg, &arg, sizeof(arg));
1972 		if (error)
1973 			return (error);
1974 		break;
1975 	}
1976 
1977 	switch (uap->cmd) {
1978 	case SEM_STAT:
1979 	case IPC_STAT:
1980 		semun.buf = &dsbuf;
1981 		break;
1982 	case IPC_SET:
1983 		error = copyin(PTRIN(arg.buf), &dsbuf32, sizeof(dsbuf32));
1984 		if (error)
1985 			return (error);
1986 		freebsd32_ipcperm_in(&dsbuf32.sem_perm, &dsbuf.sem_perm);
1987 		PTRIN_CP(dsbuf32, dsbuf, __sem_base);
1988 		CP(dsbuf32, dsbuf, sem_nsems);
1989 		CP(dsbuf32, dsbuf, sem_otime);
1990 		CP(dsbuf32, dsbuf, sem_ctime);
1991 		semun.buf = &dsbuf;
1992 		break;
1993 	case GETALL:
1994 	case SETALL:
1995 		semun.array = PTRIN(arg.array);
1996 		break;
1997 	case SETVAL:
1998 		semun.val = arg.val;
1999 		break;
2000 	}
2001 
2002 	error = kern_semctl(td, uap->semid, uap->semnum, uap->cmd, &semun,
2003 	    &rval);
2004 	if (error)
2005 		return (error);
2006 
2007 	switch (uap->cmd) {
2008 	case SEM_STAT:
2009 	case IPC_STAT:
2010 		bzero(&dsbuf32, sizeof(dsbuf32));
2011 		freebsd32_ipcperm_out(&dsbuf.sem_perm, &dsbuf32.sem_perm);
2012 		PTROUT_CP(dsbuf, dsbuf32, __sem_base);
2013 		CP(dsbuf, dsbuf32, sem_nsems);
2014 		CP(dsbuf, dsbuf32, sem_otime);
2015 		CP(dsbuf, dsbuf32, sem_ctime);
2016 		error = copyout(&dsbuf32, PTRIN(arg.buf), sizeof(dsbuf32));
2017 		break;
2018 	}
2019 
2020 	if (error == 0)
2021 		td->td_retval[0] = rval;
2022 	return (error);
2023 }
2024 
2025 #endif /* COMPAT_FREEBSD32 */
2026