xref: /freebsd/sys/kern/sysv_shm.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
1 /*	$NetBSD: sysv_shm.c,v 1.23 1994/07/04 23:25:12 glass Exp $	*/
2 /*-
3  * Copyright (c) 1994 Adam Glass and Charles Hannum.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by Adam Glass and Charles
16  *	Hannum.
17  * 4. The names of the authors may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 /*-
32  * Copyright (c) 2003-2005 McAfee, Inc.
33  * All rights reserved.
34  *
35  * This software was developed for the FreeBSD Project in part by McAfee
36  * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR
37  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research
38  * program.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  */
61 
62 #include <sys/cdefs.h>
63 __FBSDID("$FreeBSD$");
64 
65 #include "opt_compat.h"
66 #include "opt_sysvipc.h"
67 
68 #include <sys/param.h>
69 #include <sys/systm.h>
70 #include <sys/kernel.h>
71 #include <sys/limits.h>
72 #include <sys/lock.h>
73 #include <sys/sysctl.h>
74 #include <sys/shm.h>
75 #include <sys/proc.h>
76 #include <sys/malloc.h>
77 #include <sys/mman.h>
78 #include <sys/module.h>
79 #include <sys/mutex.h>
80 #include <sys/racct.h>
81 #include <sys/resourcevar.h>
82 #include <sys/stat.h>
83 #include <sys/syscall.h>
84 #include <sys/syscallsubr.h>
85 #include <sys/sysent.h>
86 #include <sys/sysproto.h>
87 #include <sys/jail.h>
88 
89 #include <security/mac/mac_framework.h>
90 
91 #include <vm/vm.h>
92 #include <vm/vm_param.h>
93 #include <vm/pmap.h>
94 #include <vm/vm_object.h>
95 #include <vm/vm_map.h>
96 #include <vm/vm_page.h>
97 #include <vm/vm_pager.h>
98 
99 FEATURE(sysv_shm, "System V shared memory segments support");
100 
101 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
102 
103 static int shmget_allocate_segment(struct thread *td,
104     struct shmget_args *uap, int mode);
105 static int shmget_existing(struct thread *td, struct shmget_args *uap,
106     int mode, int segnum);
107 
108 #define	SHMSEG_FREE     	0x0200
109 #define	SHMSEG_REMOVED  	0x0400
110 #define	SHMSEG_ALLOCATED	0x0800
111 #define	SHMSEG_WANTED		0x1000
112 
113 static int shm_last_free, shm_nused, shmalloced;
114 vm_size_t shm_committed;
115 static struct shmid_kernel	*shmsegs;
116 
117 struct shmmap_state {
118 	vm_offset_t va;
119 	int shmid;
120 };
121 
122 static void shm_deallocate_segment(struct shmid_kernel *);
123 static int shm_find_segment_by_key(key_t);
124 static struct shmid_kernel *shm_find_segment_by_shmid(int);
125 static struct shmid_kernel *shm_find_segment_by_shmidx(int);
126 static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *);
127 static void shmrealloc(void);
128 static int shminit(void);
129 static int sysvshm_modload(struct module *, int, void *);
130 static int shmunload(void);
131 static void shmexit_myhook(struct vmspace *vm);
132 static void shmfork_myhook(struct proc *p1, struct proc *p2);
133 static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS);
134 
135 /*
136  * Tuneable values.
137  */
138 #ifndef SHMMAXPGS
139 #define	SHMMAXPGS	131072	/* Note: sysv shared memory is swap backed. */
140 #endif
141 #ifndef SHMMAX
142 #define	SHMMAX	(SHMMAXPGS*PAGE_SIZE)
143 #endif
144 #ifndef SHMMIN
145 #define	SHMMIN	1
146 #endif
147 #ifndef SHMMNI
148 #define	SHMMNI	192
149 #endif
150 #ifndef SHMSEG
151 #define	SHMSEG	128
152 #endif
153 #ifndef SHMALL
154 #define	SHMALL	(SHMMAXPGS)
155 #endif
156 
157 struct	shminfo shminfo = {
158 	SHMMAX,
159 	SHMMIN,
160 	SHMMNI,
161 	SHMSEG,
162 	SHMALL
163 };
164 
165 static int shm_use_phys;
166 static int shm_allow_removed;
167 
168 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0,
169     "Maximum shared memory segment size");
170 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0,
171     "Minimum shared memory segment size");
172 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0,
173     "Number of shared memory identifiers");
174 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0,
175     "Number of segments per process");
176 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0,
177     "Maximum number of pages available for shared memory");
178 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW,
179     &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core");
180 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RW,
181     &shm_allow_removed, 0,
182     "Enable/Disable attachment to attached segments marked for removal");
183 SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD,
184     NULL, 0, sysctl_shmsegs, "",
185     "Current number of shared memory segments allocated");
186 
187 static int
188 shm_find_segment_by_key(key)
189 	key_t key;
190 {
191 	int i;
192 
193 	for (i = 0; i < shmalloced; i++)
194 		if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) &&
195 		    shmsegs[i].u.shm_perm.key == key)
196 			return (i);
197 	return (-1);
198 }
199 
200 static struct shmid_kernel *
201 shm_find_segment_by_shmid(int shmid)
202 {
203 	int segnum;
204 	struct shmid_kernel *shmseg;
205 
206 	segnum = IPCID_TO_IX(shmid);
207 	if (segnum < 0 || segnum >= shmalloced)
208 		return (NULL);
209 	shmseg = &shmsegs[segnum];
210 	if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
211 	    (!shm_allow_removed &&
212 	     (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) ||
213 	    shmseg->u.shm_perm.seq != IPCID_TO_SEQ(shmid))
214 		return (NULL);
215 	return (shmseg);
216 }
217 
218 static struct shmid_kernel *
219 shm_find_segment_by_shmidx(int segnum)
220 {
221 	struct shmid_kernel *shmseg;
222 
223 	if (segnum < 0 || segnum >= shmalloced)
224 		return (NULL);
225 	shmseg = &shmsegs[segnum];
226 	if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
227 	    (!shm_allow_removed &&
228 	     (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0))
229 		return (NULL);
230 	return (shmseg);
231 }
232 
233 static void
234 shm_deallocate_segment(shmseg)
235 	struct shmid_kernel *shmseg;
236 {
237 	vm_size_t size;
238 
239 	GIANT_REQUIRED;
240 
241 	vm_object_deallocate(shmseg->object);
242 	shmseg->object = NULL;
243 	size = round_page(shmseg->u.shm_segsz);
244 	shm_committed -= btoc(size);
245 	shm_nused--;
246 	shmseg->u.shm_perm.mode = SHMSEG_FREE;
247 #ifdef MAC
248 	mac_sysvshm_cleanup(shmseg);
249 #endif
250 	racct_sub_cred(shmseg->cred, RACCT_NSHM, 1);
251 	racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size);
252 	crfree(shmseg->cred);
253 	shmseg->cred = NULL;
254 }
255 
256 static int
257 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s)
258 {
259 	struct shmid_kernel *shmseg;
260 	int segnum, result;
261 	vm_size_t size;
262 
263 	GIANT_REQUIRED;
264 
265 	segnum = IPCID_TO_IX(shmmap_s->shmid);
266 	shmseg = &shmsegs[segnum];
267 	size = round_page(shmseg->u.shm_segsz);
268 	result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size);
269 	if (result != KERN_SUCCESS)
270 		return (EINVAL);
271 	shmmap_s->shmid = -1;
272 	shmseg->u.shm_dtime = time_second;
273 	if ((--shmseg->u.shm_nattch <= 0) &&
274 	    (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) {
275 		shm_deallocate_segment(shmseg);
276 		shm_last_free = segnum;
277 	}
278 	return (0);
279 }
280 
281 #ifndef _SYS_SYSPROTO_H_
282 struct shmdt_args {
283 	const void *shmaddr;
284 };
285 #endif
286 int
287 shmdt(td, uap)
288 	struct thread *td;
289 	struct shmdt_args *uap;
290 {
291 	struct proc *p = td->td_proc;
292 	struct shmmap_state *shmmap_s;
293 #ifdef MAC
294 	struct shmid_kernel *shmsegptr;
295 #endif
296 	int i;
297 	int error = 0;
298 
299 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
300 		return (ENOSYS);
301 	mtx_lock(&Giant);
302 	shmmap_s = p->p_vmspace->vm_shm;
303  	if (shmmap_s == NULL) {
304 		error = EINVAL;
305 		goto done2;
306 	}
307 	for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
308 		if (shmmap_s->shmid != -1 &&
309 		    shmmap_s->va == (vm_offset_t)uap->shmaddr) {
310 			break;
311 		}
312 	}
313 	if (i == shminfo.shmseg) {
314 		error = EINVAL;
315 		goto done2;
316 	}
317 #ifdef MAC
318 	shmsegptr = &shmsegs[IPCID_TO_IX(shmmap_s->shmid)];
319 	error = mac_sysvshm_check_shmdt(td->td_ucred, shmsegptr);
320 	if (error != 0)
321 		goto done2;
322 #endif
323 	error = shm_delete_mapping(p->p_vmspace, shmmap_s);
324 done2:
325 	mtx_unlock(&Giant);
326 	return (error);
327 }
328 
329 #ifndef _SYS_SYSPROTO_H_
330 struct shmat_args {
331 	int shmid;
332 	const void *shmaddr;
333 	int shmflg;
334 };
335 #endif
336 int
337 kern_shmat(td, shmid, shmaddr, shmflg)
338 	struct thread *td;
339 	int shmid;
340 	const void *shmaddr;
341 	int shmflg;
342 {
343 	struct proc *p = td->td_proc;
344 	int i, flags;
345 	struct shmid_kernel *shmseg;
346 	struct shmmap_state *shmmap_s = NULL;
347 	vm_offset_t attach_va;
348 	vm_prot_t prot;
349 	vm_size_t size;
350 	int rv;
351 	int error = 0;
352 
353 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
354 		return (ENOSYS);
355 	mtx_lock(&Giant);
356 	shmmap_s = p->p_vmspace->vm_shm;
357 	if (shmmap_s == NULL) {
358 		shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state),
359 		    M_SHM, M_WAITOK);
360 		for (i = 0; i < shminfo.shmseg; i++)
361 			shmmap_s[i].shmid = -1;
362 		p->p_vmspace->vm_shm = shmmap_s;
363 	}
364 	shmseg = shm_find_segment_by_shmid(shmid);
365 	if (shmseg == NULL) {
366 		error = EINVAL;
367 		goto done2;
368 	}
369 	error = ipcperm(td, &shmseg->u.shm_perm,
370 	    (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
371 	if (error)
372 		goto done2;
373 #ifdef MAC
374 	error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg);
375 	if (error != 0)
376 		goto done2;
377 #endif
378 	for (i = 0; i < shminfo.shmseg; i++) {
379 		if (shmmap_s->shmid == -1)
380 			break;
381 		shmmap_s++;
382 	}
383 	if (i >= shminfo.shmseg) {
384 		error = EMFILE;
385 		goto done2;
386 	}
387 	size = round_page(shmseg->u.shm_segsz);
388 	prot = VM_PROT_READ;
389 	if ((shmflg & SHM_RDONLY) == 0)
390 		prot |= VM_PROT_WRITE;
391 	flags = MAP_ANON | MAP_SHARED;
392 	if (shmaddr) {
393 		flags |= MAP_FIXED;
394 		if (shmflg & SHM_RND) {
395 			attach_va = (vm_offset_t)shmaddr & ~(SHMLBA-1);
396 		} else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0) {
397 			attach_va = (vm_offset_t)shmaddr;
398 		} else {
399 			error = EINVAL;
400 			goto done2;
401 		}
402 	} else {
403 		/*
404 		 * This is just a hint to vm_map_find() about where to
405 		 * put it.
406 		 */
407 		PROC_LOCK(p);
408 		attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr +
409 		    lim_max(p, RLIMIT_DATA));
410 		PROC_UNLOCK(p);
411 	}
412 
413 	vm_object_reference(shmseg->object);
414 	rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object,
415 	    0, &attach_va, size, (flags & MAP_FIXED) ? VMFS_NO_SPACE :
416 	    VMFS_ANY_SPACE, prot, prot, 0);
417 	if (rv != KERN_SUCCESS) {
418 		vm_object_deallocate(shmseg->object);
419 		error = ENOMEM;
420 		goto done2;
421 	}
422 	vm_map_inherit(&p->p_vmspace->vm_map,
423 		attach_va, attach_va + size, VM_INHERIT_SHARE);
424 
425 	shmmap_s->va = attach_va;
426 	shmmap_s->shmid = shmid;
427 	shmseg->u.shm_lpid = p->p_pid;
428 	shmseg->u.shm_atime = time_second;
429 	shmseg->u.shm_nattch++;
430 	td->td_retval[0] = attach_va;
431 done2:
432 	mtx_unlock(&Giant);
433 	return (error);
434 }
435 
436 int
437 shmat(td, uap)
438 	struct thread *td;
439 	struct shmat_args *uap;
440 {
441 	return kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg);
442 }
443 
444 int
445 kern_shmctl(td, shmid, cmd, buf, bufsz)
446 	struct thread *td;
447 	int shmid;
448 	int cmd;
449 	void *buf;
450 	size_t *bufsz;
451 {
452 	int error = 0;
453 	struct shmid_kernel *shmseg;
454 
455 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
456 		return (ENOSYS);
457 
458 	mtx_lock(&Giant);
459 	switch (cmd) {
460 	/*
461 	 * It is possible that kern_shmctl is being called from the Linux ABI
462 	 * layer, in which case, we will need to implement IPC_INFO.  It should
463 	 * be noted that other shmctl calls will be funneled through here for
464 	 * Linix binaries as well.
465 	 *
466 	 * NB: The Linux ABI layer will convert this data to structure(s) more
467 	 * consistent with the Linux ABI.
468 	 */
469 	case IPC_INFO:
470 		memcpy(buf, &shminfo, sizeof(shminfo));
471 		if (bufsz)
472 			*bufsz = sizeof(shminfo);
473 		td->td_retval[0] = shmalloced;
474 		goto done2;
475 	case SHM_INFO: {
476 		struct shm_info shm_info;
477 		shm_info.used_ids = shm_nused;
478 		shm_info.shm_rss = 0;	/*XXX where to get from ? */
479 		shm_info.shm_tot = 0;	/*XXX where to get from ? */
480 		shm_info.shm_swp = 0;	/*XXX where to get from ? */
481 		shm_info.swap_attempts = 0;	/*XXX where to get from ? */
482 		shm_info.swap_successes = 0;	/*XXX where to get from ? */
483 		memcpy(buf, &shm_info, sizeof(shm_info));
484 		if (bufsz)
485 			*bufsz = sizeof(shm_info);
486 		td->td_retval[0] = shmalloced;
487 		goto done2;
488 	}
489 	}
490 	if (cmd == SHM_STAT)
491 		shmseg = shm_find_segment_by_shmidx(shmid);
492 	else
493 		shmseg = shm_find_segment_by_shmid(shmid);
494 	if (shmseg == NULL) {
495 		error = EINVAL;
496 		goto done2;
497 	}
498 #ifdef MAC
499 	error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd);
500 	if (error != 0)
501 		goto done2;
502 #endif
503 	switch (cmd) {
504 	case SHM_STAT:
505 	case IPC_STAT:
506 		error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
507 		if (error)
508 			goto done2;
509 		memcpy(buf, &shmseg->u, sizeof(struct shmid_ds));
510 		if (bufsz)
511 			*bufsz = sizeof(struct shmid_ds);
512 		if (cmd == SHM_STAT)
513 			td->td_retval[0] = IXSEQ_TO_IPCID(shmid, shmseg->u.shm_perm);
514 		break;
515 	case IPC_SET: {
516 		struct shmid_ds *shmid;
517 
518 		shmid = (struct shmid_ds *)buf;
519 		error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
520 		if (error)
521 			goto done2;
522 		shmseg->u.shm_perm.uid = shmid->shm_perm.uid;
523 		shmseg->u.shm_perm.gid = shmid->shm_perm.gid;
524 		shmseg->u.shm_perm.mode =
525 		    (shmseg->u.shm_perm.mode & ~ACCESSPERMS) |
526 		    (shmid->shm_perm.mode & ACCESSPERMS);
527 		shmseg->u.shm_ctime = time_second;
528 		break;
529 	}
530 	case IPC_RMID:
531 		error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
532 		if (error)
533 			goto done2;
534 		shmseg->u.shm_perm.key = IPC_PRIVATE;
535 		shmseg->u.shm_perm.mode |= SHMSEG_REMOVED;
536 		if (shmseg->u.shm_nattch <= 0) {
537 			shm_deallocate_segment(shmseg);
538 			shm_last_free = IPCID_TO_IX(shmid);
539 		}
540 		break;
541 #if 0
542 	case SHM_LOCK:
543 	case SHM_UNLOCK:
544 #endif
545 	default:
546 		error = EINVAL;
547 		break;
548 	}
549 done2:
550 	mtx_unlock(&Giant);
551 	return (error);
552 }
553 
554 #ifndef _SYS_SYSPROTO_H_
555 struct shmctl_args {
556 	int shmid;
557 	int cmd;
558 	struct shmid_ds *buf;
559 };
560 #endif
561 int
562 shmctl(td, uap)
563 	struct thread *td;
564 	struct shmctl_args *uap;
565 {
566 	int error = 0;
567 	struct shmid_ds buf;
568 	size_t bufsz;
569 
570 	/*
571 	 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
572 	 * Linux binaries.  If we see the call come through the FreeBSD ABI,
573 	 * return an error back to the user since we do not to support this.
574 	 */
575 	if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
576 	    uap->cmd == SHM_STAT)
577 		return (EINVAL);
578 
579 	/* IPC_SET needs to copyin the buffer before calling kern_shmctl */
580 	if (uap->cmd == IPC_SET) {
581 		if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds))))
582 			goto done;
583 	}
584 
585 	error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
586 	if (error)
587 		goto done;
588 
589 	/* Cases in which we need to copyout */
590 	switch (uap->cmd) {
591 	case IPC_STAT:
592 		error = copyout(&buf, uap->buf, bufsz);
593 		break;
594 	}
595 
596 done:
597 	if (error) {
598 		/* Invalidate the return value */
599 		td->td_retval[0] = -1;
600 	}
601 	return (error);
602 }
603 
604 
605 static int
606 shmget_existing(td, uap, mode, segnum)
607 	struct thread *td;
608 	struct shmget_args *uap;
609 	int mode;
610 	int segnum;
611 {
612 	struct shmid_kernel *shmseg;
613 	int error;
614 
615 	shmseg = &shmsegs[segnum];
616 	if (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) {
617 		/*
618 		 * This segment is in the process of being allocated.  Wait
619 		 * until it's done, and look the key up again (in case the
620 		 * allocation failed or it was freed).
621 		 */
622 		shmseg->u.shm_perm.mode |= SHMSEG_WANTED;
623 		error = tsleep(shmseg, PLOCK | PCATCH, "shmget", 0);
624 		if (error)
625 			return (error);
626 		return (EAGAIN);
627 	}
628 	if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
629 		return (EEXIST);
630 #ifdef MAC
631 	error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg);
632 	if (error != 0)
633 		return (error);
634 #endif
635 	if (uap->size != 0 && uap->size > shmseg->u.shm_segsz)
636 		return (EINVAL);
637 	td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
638 	return (0);
639 }
640 
641 static int
642 shmget_allocate_segment(td, uap, mode)
643 	struct thread *td;
644 	struct shmget_args *uap;
645 	int mode;
646 {
647 	int i, segnum, shmid;
648 	size_t size;
649 	struct ucred *cred = td->td_ucred;
650 	struct shmid_kernel *shmseg;
651 	vm_object_t shm_object;
652 
653 	GIANT_REQUIRED;
654 
655 	if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
656 		return (EINVAL);
657 	if (shm_nused >= shminfo.shmmni) /* Any shmids left? */
658 		return (ENOSPC);
659 	size = round_page(uap->size);
660 	if (shm_committed + btoc(size) > shminfo.shmall)
661 		return (ENOMEM);
662 	if (shm_last_free < 0) {
663 		shmrealloc();	/* Maybe expand the shmsegs[] array. */
664 		for (i = 0; i < shmalloced; i++)
665 			if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE)
666 				break;
667 		if (i == shmalloced)
668 			return (ENOSPC);
669 		segnum = i;
670 	} else  {
671 		segnum = shm_last_free;
672 		shm_last_free = -1;
673 	}
674 	shmseg = &shmsegs[segnum];
675 	PROC_LOCK(td->td_proc);
676 	if (racct_add(td->td_proc, RACCT_NSHM, 1)) {
677 		PROC_UNLOCK(td->td_proc);
678 		return (ENOSPC);
679 	}
680 	if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) {
681 		racct_sub(td->td_proc, RACCT_NSHM, 1);
682 		PROC_UNLOCK(td->td_proc);
683 		return (ENOMEM);
684 	}
685 	PROC_UNLOCK(td->td_proc);
686 	/*
687 	 * In case we sleep in malloc(), mark the segment present but deleted
688 	 * so that noone else tries to create the same key.
689 	 */
690 	shmseg->u.shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED;
691 	shmseg->u.shm_perm.key = uap->key;
692 	shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff;
693 	shmid = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
694 
695 	/*
696 	 * We make sure that we have allocated a pager before we need
697 	 * to.
698 	 */
699 	shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP,
700 	    0, size, VM_PROT_DEFAULT, 0, cred);
701 	if (shm_object == NULL) {
702 		PROC_LOCK(td->td_proc);
703 		racct_sub(td->td_proc, RACCT_NSHM, 1);
704 		racct_sub(td->td_proc, RACCT_SHMSIZE, size);
705 		PROC_UNLOCK(td->td_proc);
706 		return (ENOMEM);
707 	}
708 	VM_OBJECT_LOCK(shm_object);
709 	vm_object_clear_flag(shm_object, OBJ_ONEMAPPING);
710 	vm_object_set_flag(shm_object, OBJ_NOSPLIT);
711 	VM_OBJECT_UNLOCK(shm_object);
712 
713 	shmseg->object = shm_object;
714 	shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid;
715 	shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid;
716 	shmseg->u.shm_perm.mode = (shmseg->u.shm_perm.mode & SHMSEG_WANTED) |
717 	    (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
718 	shmseg->cred = crhold(cred);
719 	shmseg->u.shm_segsz = uap->size;
720 	shmseg->u.shm_cpid = td->td_proc->p_pid;
721 	shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0;
722 	shmseg->u.shm_atime = shmseg->u.shm_dtime = 0;
723 #ifdef MAC
724 	mac_sysvshm_create(cred, shmseg);
725 #endif
726 	shmseg->u.shm_ctime = time_second;
727 	shm_committed += btoc(size);
728 	shm_nused++;
729 	if (shmseg->u.shm_perm.mode & SHMSEG_WANTED) {
730 		/*
731 		 * Somebody else wanted this key while we were asleep.  Wake
732 		 * them up now.
733 		 */
734 		shmseg->u.shm_perm.mode &= ~SHMSEG_WANTED;
735 		wakeup(shmseg);
736 	}
737 	td->td_retval[0] = shmid;
738 	return (0);
739 }
740 
741 #ifndef _SYS_SYSPROTO_H_
742 struct shmget_args {
743 	key_t key;
744 	size_t size;
745 	int shmflg;
746 };
747 #endif
748 int
749 shmget(td, uap)
750 	struct thread *td;
751 	struct shmget_args *uap;
752 {
753 	int segnum, mode;
754 	int error;
755 
756 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
757 		return (ENOSYS);
758 	mtx_lock(&Giant);
759 	mode = uap->shmflg & ACCESSPERMS;
760 	if (uap->key != IPC_PRIVATE) {
761 	again:
762 		segnum = shm_find_segment_by_key(uap->key);
763 		if (segnum >= 0) {
764 			error = shmget_existing(td, uap, mode, segnum);
765 			if (error == EAGAIN)
766 				goto again;
767 			goto done2;
768 		}
769 		if ((uap->shmflg & IPC_CREAT) == 0) {
770 			error = ENOENT;
771 			goto done2;
772 		}
773 	}
774 	error = shmget_allocate_segment(td, uap, mode);
775 done2:
776 	mtx_unlock(&Giant);
777 	return (error);
778 }
779 
780 static void
781 shmfork_myhook(p1, p2)
782 	struct proc *p1, *p2;
783 {
784 	struct shmmap_state *shmmap_s;
785 	size_t size;
786 	int i;
787 
788 	mtx_lock(&Giant);
789 	size = shminfo.shmseg * sizeof(struct shmmap_state);
790 	shmmap_s = malloc(size, M_SHM, M_WAITOK);
791 	bcopy(p1->p_vmspace->vm_shm, shmmap_s, size);
792 	p2->p_vmspace->vm_shm = shmmap_s;
793 	for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
794 		if (shmmap_s->shmid != -1)
795 			shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++;
796 	mtx_unlock(&Giant);
797 }
798 
799 static void
800 shmexit_myhook(struct vmspace *vm)
801 {
802 	struct shmmap_state *base, *shm;
803 	int i;
804 
805 	if ((base = vm->vm_shm) != NULL) {
806 		vm->vm_shm = NULL;
807 		mtx_lock(&Giant);
808 		for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) {
809 			if (shm->shmid != -1)
810 				shm_delete_mapping(vm, shm);
811 		}
812 		mtx_unlock(&Giant);
813 		free(base, M_SHM);
814 	}
815 }
816 
817 static void
818 shmrealloc(void)
819 {
820 	int i;
821 	struct shmid_kernel *newsegs;
822 
823 	if (shmalloced >= shminfo.shmmni)
824 		return;
825 
826 	newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK);
827 	if (newsegs == NULL)
828 		return;
829 	for (i = 0; i < shmalloced; i++)
830 		bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
831 	for (; i < shminfo.shmmni; i++) {
832 		shmsegs[i].u.shm_perm.mode = SHMSEG_FREE;
833 		shmsegs[i].u.shm_perm.seq = 0;
834 #ifdef MAC
835 		mac_sysvshm_init(&shmsegs[i]);
836 #endif
837 	}
838 	free(shmsegs, M_SHM);
839 	shmsegs = newsegs;
840 	shmalloced = shminfo.shmmni;
841 }
842 
843 static struct syscall_helper_data shm_syscalls[] = {
844 	SYSCALL_INIT_HELPER(shmat),
845 	SYSCALL_INIT_HELPER(shmctl),
846 	SYSCALL_INIT_HELPER(shmdt),
847 	SYSCALL_INIT_HELPER(shmget),
848 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
849     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
850 	SYSCALL_INIT_HELPER(freebsd7_shmctl),
851 #endif
852 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
853 	SYSCALL_INIT_HELPER(shmsys),
854 #endif
855 	SYSCALL_INIT_LAST
856 };
857 
858 #ifdef COMPAT_FREEBSD32
859 #include <compat/freebsd32/freebsd32.h>
860 #include <compat/freebsd32/freebsd32_ipc.h>
861 #include <compat/freebsd32/freebsd32_proto.h>
862 #include <compat/freebsd32/freebsd32_signal.h>
863 #include <compat/freebsd32/freebsd32_syscall.h>
864 #include <compat/freebsd32/freebsd32_util.h>
865 
866 static struct syscall_helper_data shm32_syscalls[] = {
867 	SYSCALL32_INIT_HELPER(shmat),
868 	SYSCALL32_INIT_HELPER(shmdt),
869 	SYSCALL32_INIT_HELPER(shmget),
870 	SYSCALL32_INIT_HELPER(freebsd32_shmsys),
871 	SYSCALL32_INIT_HELPER(freebsd32_shmctl),
872 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
873     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
874 	SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl),
875 #endif
876 	SYSCALL_INIT_LAST
877 };
878 #endif
879 
880 static int
881 shminit()
882 {
883 	int i, error;
884 
885 #ifndef BURN_BRIDGES
886 	if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0)
887 		printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n");
888 #endif
889 	TUNABLE_ULONG_FETCH("kern.ipc.shmall", &shminfo.shmall);
890 
891 	/* Initialize shmmax dealing with possible overflow. */
892 	for (i = PAGE_SIZE; i > 0; i--) {
893 		shminfo.shmmax = shminfo.shmall * i;
894 		if (shminfo.shmmax >= shminfo.shmall)
895 			break;
896 	}
897 
898 	TUNABLE_ULONG_FETCH("kern.ipc.shmmin", &shminfo.shmmin);
899 	TUNABLE_ULONG_FETCH("kern.ipc.shmmni", &shminfo.shmmni);
900 	TUNABLE_ULONG_FETCH("kern.ipc.shmseg", &shminfo.shmseg);
901 	TUNABLE_INT_FETCH("kern.ipc.shm_use_phys", &shm_use_phys);
902 
903 	shmalloced = shminfo.shmmni;
904 	shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK);
905 	for (i = 0; i < shmalloced; i++) {
906 		shmsegs[i].u.shm_perm.mode = SHMSEG_FREE;
907 		shmsegs[i].u.shm_perm.seq = 0;
908 #ifdef MAC
909 		mac_sysvshm_init(&shmsegs[i]);
910 #endif
911 	}
912 	shm_last_free = 0;
913 	shm_nused = 0;
914 	shm_committed = 0;
915 	shmexit_hook = &shmexit_myhook;
916 	shmfork_hook = &shmfork_myhook;
917 
918 	error = syscall_helper_register(shm_syscalls);
919 	if (error != 0)
920 		return (error);
921 #ifdef COMPAT_FREEBSD32
922 	error = syscall32_helper_register(shm32_syscalls);
923 	if (error != 0)
924 		return (error);
925 #endif
926 	return (0);
927 }
928 
929 static int
930 shmunload()
931 {
932 	int i;
933 
934 	if (shm_nused > 0)
935 		return (EBUSY);
936 
937 #ifdef COMPAT_FREEBSD32
938 	syscall32_helper_unregister(shm32_syscalls);
939 #endif
940 	syscall_helper_unregister(shm_syscalls);
941 
942 	for (i = 0; i < shmalloced; i++) {
943 #ifdef MAC
944 		mac_sysvshm_destroy(&shmsegs[i]);
945 #endif
946 		/*
947 		 * Objects might be still mapped into the processes
948 		 * address spaces.  Actual free would happen on the
949 		 * last mapping destruction.
950 		 */
951 		if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE)
952 			vm_object_deallocate(shmsegs[i].object);
953 	}
954 	free(shmsegs, M_SHM);
955 	shmexit_hook = NULL;
956 	shmfork_hook = NULL;
957 	return (0);
958 }
959 
960 static int
961 sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
962 {
963 
964 	return (SYSCTL_OUT(req, shmsegs, shmalloced * sizeof(shmsegs[0])));
965 }
966 
967 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
968 struct oshmid_ds {
969 	struct	ipc_perm_old shm_perm;	/* operation perms */
970 	int	shm_segsz;		/* size of segment (bytes) */
971 	u_short	shm_cpid;		/* pid, creator */
972 	u_short	shm_lpid;		/* pid, last operation */
973 	short	shm_nattch;		/* no. of current attaches */
974 	time_t	shm_atime;		/* last attach time */
975 	time_t	shm_dtime;		/* last detach time */
976 	time_t	shm_ctime;		/* last change time */
977 	void	*shm_handle;		/* internal handle for shm segment */
978 };
979 
980 struct oshmctl_args {
981 	int shmid;
982 	int cmd;
983 	struct oshmid_ds *ubuf;
984 };
985 
986 static int
987 oshmctl(struct thread *td, struct oshmctl_args *uap)
988 {
989 #ifdef COMPAT_43
990 	int error = 0;
991 	struct shmid_kernel *shmseg;
992 	struct oshmid_ds outbuf;
993 
994 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
995 		return (ENOSYS);
996 	mtx_lock(&Giant);
997 	shmseg = shm_find_segment_by_shmid(uap->shmid);
998 	if (shmseg == NULL) {
999 		error = EINVAL;
1000 		goto done2;
1001 	}
1002 	switch (uap->cmd) {
1003 	case IPC_STAT:
1004 		error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
1005 		if (error)
1006 			goto done2;
1007 #ifdef MAC
1008 		error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd);
1009 		if (error != 0)
1010 			goto done2;
1011 #endif
1012 		ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm);
1013 		outbuf.shm_segsz = shmseg->u.shm_segsz;
1014 		outbuf.shm_cpid = shmseg->u.shm_cpid;
1015 		outbuf.shm_lpid = shmseg->u.shm_lpid;
1016 		outbuf.shm_nattch = shmseg->u.shm_nattch;
1017 		outbuf.shm_atime = shmseg->u.shm_atime;
1018 		outbuf.shm_dtime = shmseg->u.shm_dtime;
1019 		outbuf.shm_ctime = shmseg->u.shm_ctime;
1020 		outbuf.shm_handle = shmseg->object;
1021 		error = copyout(&outbuf, uap->ubuf, sizeof(outbuf));
1022 		if (error)
1023 			goto done2;
1024 		break;
1025 	default:
1026 		error = freebsd7_shmctl(td, (struct freebsd7_shmctl_args *)uap);
1027 		break;
1028 	}
1029 done2:
1030 	mtx_unlock(&Giant);
1031 	return (error);
1032 #else
1033 	return (EINVAL);
1034 #endif
1035 }
1036 
1037 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1038 static sy_call_t *shmcalls[] = {
1039 	(sy_call_t *)shmat, (sy_call_t *)oshmctl,
1040 	(sy_call_t *)shmdt, (sy_call_t *)shmget,
1041 	(sy_call_t *)freebsd7_shmctl
1042 };
1043 
1044 int
1045 shmsys(td, uap)
1046 	struct thread *td;
1047 	/* XXX actually varargs. */
1048 	struct shmsys_args /* {
1049 		int	which;
1050 		int	a2;
1051 		int	a3;
1052 		int	a4;
1053 	} */ *uap;
1054 {
1055 	int error;
1056 
1057 	if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
1058 		return (ENOSYS);
1059 	if (uap->which < 0 ||
1060 	    uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
1061 		return (EINVAL);
1062 	mtx_lock(&Giant);
1063 	error = (*shmcalls[uap->which])(td, &uap->a2);
1064 	mtx_unlock(&Giant);
1065 	return (error);
1066 }
1067 
1068 #endif	/* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */
1069 
1070 #ifdef COMPAT_FREEBSD32
1071 
1072 int
1073 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap)
1074 {
1075 
1076 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1077     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1078 	switch (uap->which) {
1079 	case 0:	{	/* shmat */
1080 		struct shmat_args ap;
1081 
1082 		ap.shmid = uap->a2;
1083 		ap.shmaddr = PTRIN(uap->a3);
1084 		ap.shmflg = uap->a4;
1085 		return (sysent[SYS_shmat].sy_call(td, &ap));
1086 	}
1087 	case 2: {	/* shmdt */
1088 		struct shmdt_args ap;
1089 
1090 		ap.shmaddr = PTRIN(uap->a2);
1091 		return (sysent[SYS_shmdt].sy_call(td, &ap));
1092 	}
1093 	case 3: {	/* shmget */
1094 		struct shmget_args ap;
1095 
1096 		ap.key = uap->a2;
1097 		ap.size = uap->a3;
1098 		ap.shmflg = uap->a4;
1099 		return (sysent[SYS_shmget].sy_call(td, &ap));
1100 	}
1101 	case 4: {	/* shmctl */
1102 		struct freebsd7_freebsd32_shmctl_args ap;
1103 
1104 		ap.shmid = uap->a2;
1105 		ap.cmd = uap->a3;
1106 		ap.buf = PTRIN(uap->a4);
1107 		return (freebsd7_freebsd32_shmctl(td, &ap));
1108 	}
1109 	case 1:		/* oshmctl */
1110 	default:
1111 		return (EINVAL);
1112 	}
1113 #else
1114 	return (nosys(td, NULL));
1115 #endif
1116 }
1117 
1118 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1119     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1120 int
1121 freebsd7_freebsd32_shmctl(struct thread *td,
1122     struct freebsd7_freebsd32_shmctl_args *uap)
1123 {
1124 	int error = 0;
1125 	union {
1126 		struct shmid_ds shmid_ds;
1127 		struct shm_info shm_info;
1128 		struct shminfo shminfo;
1129 	} u;
1130 	union {
1131 		struct shmid_ds32_old shmid_ds32;
1132 		struct shm_info32 shm_info32;
1133 		struct shminfo32 shminfo32;
1134 	} u32;
1135 	size_t sz;
1136 
1137 	if (uap->cmd == IPC_SET) {
1138 		if ((error = copyin(uap->buf, &u32.shmid_ds32,
1139 		    sizeof(u32.shmid_ds32))))
1140 			goto done;
1141 		freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm,
1142 		    &u.shmid_ds.shm_perm);
1143 		CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1144 		CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1145 		CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1146 		CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1147 		CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1148 		CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1149 		CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1150 	}
1151 
1152 	error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1153 	if (error)
1154 		goto done;
1155 
1156 	/* Cases in which we need to copyout */
1157 	switch (uap->cmd) {
1158 	case IPC_INFO:
1159 		CP(u.shminfo, u32.shminfo32, shmmax);
1160 		CP(u.shminfo, u32.shminfo32, shmmin);
1161 		CP(u.shminfo, u32.shminfo32, shmmni);
1162 		CP(u.shminfo, u32.shminfo32, shmseg);
1163 		CP(u.shminfo, u32.shminfo32, shmall);
1164 		error = copyout(&u32.shminfo32, uap->buf,
1165 		    sizeof(u32.shminfo32));
1166 		break;
1167 	case SHM_INFO:
1168 		CP(u.shm_info, u32.shm_info32, used_ids);
1169 		CP(u.shm_info, u32.shm_info32, shm_rss);
1170 		CP(u.shm_info, u32.shm_info32, shm_tot);
1171 		CP(u.shm_info, u32.shm_info32, shm_swp);
1172 		CP(u.shm_info, u32.shm_info32, swap_attempts);
1173 		CP(u.shm_info, u32.shm_info32, swap_successes);
1174 		error = copyout(&u32.shm_info32, uap->buf,
1175 		    sizeof(u32.shm_info32));
1176 		break;
1177 	case SHM_STAT:
1178 	case IPC_STAT:
1179 		freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm,
1180 		    &u32.shmid_ds32.shm_perm);
1181 		if (u.shmid_ds.shm_segsz > INT32_MAX)
1182 			u32.shmid_ds32.shm_segsz = INT32_MAX;
1183 		else
1184 			CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1185 		CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1186 		CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1187 		CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1188 		CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1189 		CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1190 		CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1191 		u32.shmid_ds32.shm_internal = 0;
1192 		error = copyout(&u32.shmid_ds32, uap->buf,
1193 		    sizeof(u32.shmid_ds32));
1194 		break;
1195 	}
1196 
1197 done:
1198 	if (error) {
1199 		/* Invalidate the return value */
1200 		td->td_retval[0] = -1;
1201 	}
1202 	return (error);
1203 }
1204 #endif
1205 
1206 int
1207 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap)
1208 {
1209 	int error = 0;
1210 	union {
1211 		struct shmid_ds shmid_ds;
1212 		struct shm_info shm_info;
1213 		struct shminfo shminfo;
1214 	} u;
1215 	union {
1216 		struct shmid_ds32 shmid_ds32;
1217 		struct shm_info32 shm_info32;
1218 		struct shminfo32 shminfo32;
1219 	} u32;
1220 	size_t sz;
1221 
1222 	if (uap->cmd == IPC_SET) {
1223 		if ((error = copyin(uap->buf, &u32.shmid_ds32,
1224 		    sizeof(u32.shmid_ds32))))
1225 			goto done;
1226 		freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm,
1227 		    &u.shmid_ds.shm_perm);
1228 		CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1229 		CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1230 		CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1231 		CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1232 		CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1233 		CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1234 		CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1235 	}
1236 
1237 	error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1238 	if (error)
1239 		goto done;
1240 
1241 	/* Cases in which we need to copyout */
1242 	switch (uap->cmd) {
1243 	case IPC_INFO:
1244 		CP(u.shminfo, u32.shminfo32, shmmax);
1245 		CP(u.shminfo, u32.shminfo32, shmmin);
1246 		CP(u.shminfo, u32.shminfo32, shmmni);
1247 		CP(u.shminfo, u32.shminfo32, shmseg);
1248 		CP(u.shminfo, u32.shminfo32, shmall);
1249 		error = copyout(&u32.shminfo32, uap->buf,
1250 		    sizeof(u32.shminfo32));
1251 		break;
1252 	case SHM_INFO:
1253 		CP(u.shm_info, u32.shm_info32, used_ids);
1254 		CP(u.shm_info, u32.shm_info32, shm_rss);
1255 		CP(u.shm_info, u32.shm_info32, shm_tot);
1256 		CP(u.shm_info, u32.shm_info32, shm_swp);
1257 		CP(u.shm_info, u32.shm_info32, swap_attempts);
1258 		CP(u.shm_info, u32.shm_info32, swap_successes);
1259 		error = copyout(&u32.shm_info32, uap->buf,
1260 		    sizeof(u32.shm_info32));
1261 		break;
1262 	case SHM_STAT:
1263 	case IPC_STAT:
1264 		freebsd32_ipcperm_out(&u.shmid_ds.shm_perm,
1265 		    &u32.shmid_ds32.shm_perm);
1266 		if (u.shmid_ds.shm_segsz > INT32_MAX)
1267 			u32.shmid_ds32.shm_segsz = INT32_MAX;
1268 		else
1269 			CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1270 		CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1271 		CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1272 		CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1273 		CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1274 		CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1275 		CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1276 		error = copyout(&u32.shmid_ds32, uap->buf,
1277 		    sizeof(u32.shmid_ds32));
1278 		break;
1279 	}
1280 
1281 done:
1282 	if (error) {
1283 		/* Invalidate the return value */
1284 		td->td_retval[0] = -1;
1285 	}
1286 	return (error);
1287 }
1288 #endif
1289 
1290 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1291     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1292 
1293 #ifndef CP
1294 #define CP(src, dst, fld)	do { (dst).fld = (src).fld; } while (0)
1295 #endif
1296 
1297 #ifndef _SYS_SYSPROTO_H_
1298 struct freebsd7_shmctl_args {
1299 	int shmid;
1300 	int cmd;
1301 	struct shmid_ds_old *buf;
1302 };
1303 #endif
1304 int
1305 freebsd7_shmctl(td, uap)
1306 	struct thread *td;
1307 	struct freebsd7_shmctl_args *uap;
1308 {
1309 	int error = 0;
1310 	struct shmid_ds_old old;
1311 	struct shmid_ds buf;
1312 	size_t bufsz;
1313 
1314 	/*
1315 	 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
1316 	 * Linux binaries.  If we see the call come through the FreeBSD ABI,
1317 	 * return an error back to the user since we do not to support this.
1318 	 */
1319 	if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
1320 	    uap->cmd == SHM_STAT)
1321 		return (EINVAL);
1322 
1323 	/* IPC_SET needs to copyin the buffer before calling kern_shmctl */
1324 	if (uap->cmd == IPC_SET) {
1325 		if ((error = copyin(uap->buf, &old, sizeof(old))))
1326 			goto done;
1327 		ipcperm_old2new(&old.shm_perm, &buf.shm_perm);
1328 		CP(old, buf, shm_segsz);
1329 		CP(old, buf, shm_lpid);
1330 		CP(old, buf, shm_cpid);
1331 		CP(old, buf, shm_nattch);
1332 		CP(old, buf, shm_atime);
1333 		CP(old, buf, shm_dtime);
1334 		CP(old, buf, shm_ctime);
1335 	}
1336 
1337 	error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
1338 	if (error)
1339 		goto done;
1340 
1341 	/* Cases in which we need to copyout */
1342 	switch (uap->cmd) {
1343 	case IPC_STAT:
1344 		ipcperm_new2old(&buf.shm_perm, &old.shm_perm);
1345 		if (buf.shm_segsz > INT_MAX)
1346 			old.shm_segsz = INT_MAX;
1347 		else
1348 			CP(buf, old, shm_segsz);
1349 		CP(buf, old, shm_lpid);
1350 		CP(buf, old, shm_cpid);
1351 		if (buf.shm_nattch > SHRT_MAX)
1352 			old.shm_nattch = SHRT_MAX;
1353 		else
1354 			CP(buf, old, shm_nattch);
1355 		CP(buf, old, shm_atime);
1356 		CP(buf, old, shm_dtime);
1357 		CP(buf, old, shm_ctime);
1358 		old.shm_internal = NULL;
1359 		error = copyout(&old, uap->buf, sizeof(old));
1360 		break;
1361 	}
1362 
1363 done:
1364 	if (error) {
1365 		/* Invalidate the return value */
1366 		td->td_retval[0] = -1;
1367 	}
1368 	return (error);
1369 }
1370 
1371 #endif	/* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1372 	   COMPAT_FREEBSD7 */
1373 
1374 static int
1375 sysvshm_modload(struct module *module, int cmd, void *arg)
1376 {
1377 	int error = 0;
1378 
1379 	switch (cmd) {
1380 	case MOD_LOAD:
1381 		error = shminit();
1382 		if (error != 0)
1383 			shmunload();
1384 		break;
1385 	case MOD_UNLOAD:
1386 		error = shmunload();
1387 		break;
1388 	case MOD_SHUTDOWN:
1389 		break;
1390 	default:
1391 		error = EINVAL;
1392 		break;
1393 	}
1394 	return (error);
1395 }
1396 
1397 static moduledata_t sysvshm_mod = {
1398 	"sysvshm",
1399 	&sysvshm_modload,
1400 	NULL
1401 };
1402 
1403 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
1404 MODULE_VERSION(sysvshm, 1);
1405