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1/* $FreeBSD: head/sys/kern/sysv_shm.c 79224 2001-07-04 16:20:28Z dillon $ */
1/* $FreeBSD: head/sys/kern/sysv_shm.c 82607 2001-08-31 00:02:18Z dillon $ */
2/* $NetBSD: sysv_shm.c,v 1.23 1994/07/04 23:25:12 glass Exp $ */
3
4/*
5 * Copyright (c) 1994 Adam Glass and Charles Hannum. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Adam Glass and Charles
18 * Hannum.
19 * 4. The names of the authors may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include "opt_compat.h"
35#include "opt_rlimit.h"
36#include "opt_sysvipc.h"
37
38#include <sys/param.h>
39#include <sys/systm.h>
40#include <sys/kernel.h>
41#include <sys/lock.h>
42#include <sys/sysctl.h>
43#include <sys/shm.h>
44#include <sys/proc.h>
45#include <sys/malloc.h>
46#include <sys/mman.h>
47#include <sys/mutex.h>
48#include <sys/stat.h>
49#include <sys/syscall.h>
50#include <sys/sysent.h>
51#include <sys/sysproto.h>
52#include <sys/jail.h>
53
54#include <vm/vm.h>
55#include <vm/vm_param.h>
56#include <vm/pmap.h>
57#include <vm/vm_object.h>
58#include <vm/vm_map.h>
59#include <vm/vm_page.h>
60#include <vm/vm_pager.h>
61
62static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
63
64struct oshmctl_args;
65static int oshmctl __P((struct proc *p, struct oshmctl_args *uap));
66
67static int shmget_allocate_segment __P((struct proc *p,
68 struct shmget_args *uap, int mode));
69static int shmget_existing __P((struct proc *p, struct shmget_args *uap,
70 int mode, int segnum));
71
72/* XXX casting to (sy_call_t *) is bogus, as usual. */
73static sy_call_t *shmcalls[] = {
74 (sy_call_t *)shmat, (sy_call_t *)oshmctl,
75 (sy_call_t *)shmdt, (sy_call_t *)shmget,
76 (sy_call_t *)shmctl
77};
78
79#define SHMSEG_FREE 0x0200
80#define SHMSEG_REMOVED 0x0400
81#define SHMSEG_ALLOCATED 0x0800
82#define SHMSEG_WANTED 0x1000
83
84static int shm_last_free, shm_nused, shm_committed, shmalloced;
85static struct shmid_ds *shmsegs;
86
87struct shm_handle {
88 /* vm_offset_t kva; */
89 vm_object_t shm_object;
90};
91
92struct shmmap_state {
93 vm_offset_t va;
94 int shmid;
95};
96
97static void shm_deallocate_segment __P((struct shmid_ds *));
98static int shm_find_segment_by_key __P((key_t));
99static struct shmid_ds *shm_find_segment_by_shmid __P((int));
100static int shm_delete_mapping __P((struct proc *, struct shmmap_state *));
101static void shmrealloc __P((void));
102static void shminit __P((void));
103static int sysvshm_modload __P((struct module *, int, void *));
104static int shmunload __P((void));
105static void shmexit_myhook __P((struct proc *p));
106static void shmfork_myhook __P((struct proc *p1, struct proc *p2));
107static int sysctl_shmsegs __P((SYSCTL_HANDLER_ARGS));
108
109/*
110 * Tuneable values.
111 */
112#ifndef SHMMAXPGS
113#define SHMMAXPGS 8192 /* Note: sysv shared memory is swap backed. */
114#endif
115#ifndef SHMMAX
116#define SHMMAX (SHMMAXPGS*PAGE_SIZE)
117#endif
118#ifndef SHMMIN
119#define SHMMIN 1
120#endif
121#ifndef SHMMNI
122#define SHMMNI 192
123#endif
124#ifndef SHMSEG
125#define SHMSEG 128
126#endif
127#ifndef SHMALL
128#define SHMALL (SHMMAXPGS)
129#endif
130
131struct shminfo shminfo = {
132 SHMMAX,
133 SHMMIN,
134 SHMMNI,
135 SHMSEG,
136 SHMALL
137};
138
139static int shm_use_phys;
140
141SYSCTL_DECL(_kern_ipc);
142SYSCTL_INT(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0, "");
143SYSCTL_INT(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0, "");
144SYSCTL_INT(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RD, &shminfo.shmmni, 0, "");
145SYSCTL_INT(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RD, &shminfo.shmseg, 0, "");
146SYSCTL_INT(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0, "");
147SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW,
148 &shm_use_phys, 0, "");
149SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLFLAG_RD,
150 NULL, 0, sysctl_shmsegs, "", "");
151
152static int
153shm_find_segment_by_key(key)
154 key_t key;
155{
156 int i;
157
158 for (i = 0; i < shmalloced; i++)
159 if ((shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED) &&
160 shmsegs[i].shm_perm.key == key)
161 return i;
162 return -1;
163}
164
165static struct shmid_ds *
166shm_find_segment_by_shmid(shmid)
167 int shmid;
168{
169 int segnum;
170 struct shmid_ds *shmseg;
171
172 segnum = IPCID_TO_IX(shmid);
173 if (segnum < 0 || segnum >= shmalloced)
174 return NULL;
175 shmseg = &shmsegs[segnum];
176 if ((shmseg->shm_perm.mode & (SHMSEG_ALLOCATED | SHMSEG_REMOVED))
177 != SHMSEG_ALLOCATED ||
178 shmseg->shm_perm.seq != IPCID_TO_SEQ(shmid))
179 return NULL;
180 return shmseg;
181}
182
183static void
184shm_deallocate_segment(shmseg)
185 struct shmid_ds *shmseg;
186{
187 struct shm_handle *shm_handle;
188 size_t size;
189
190 GIANT_REQUIRED;
191
192 shm_handle = shmseg->shm_internal;
193 vm_object_deallocate(shm_handle->shm_object);
194 free((caddr_t)shm_handle, M_SHM);
195 shmseg->shm_internal = NULL;
196 size = round_page(shmseg->shm_segsz);
197 shm_committed -= btoc(size);
198 shm_nused--;
199 shmseg->shm_perm.mode = SHMSEG_FREE;
200}
201
202static int
203shm_delete_mapping(p, shmmap_s)
204 struct proc *p;
205 struct shmmap_state *shmmap_s;
206{
207 struct shmid_ds *shmseg;
208 int segnum, result;
209 size_t size;
210
211 GIANT_REQUIRED;
212
213 segnum = IPCID_TO_IX(shmmap_s->shmid);
214 shmseg = &shmsegs[segnum];
215 size = round_page(shmseg->shm_segsz);
216 result = vm_map_remove(&p->p_vmspace->vm_map, shmmap_s->va,
217 shmmap_s->va + size);
218 if (result != KERN_SUCCESS)
219 return EINVAL;
220 shmmap_s->shmid = -1;
221 shmseg->shm_dtime = time_second;
222 if ((--shmseg->shm_nattch <= 0) &&
223 (shmseg->shm_perm.mode & SHMSEG_REMOVED)) {
224 shm_deallocate_segment(shmseg);
225 shm_last_free = segnum;
226 }
227 return 0;
228}
229
230#ifndef _SYS_SYSPROTO_H_
231struct shmdt_args {
232 void *shmaddr;
233};
234#endif
235
236/*
237 * MPSAFE
238 */
239int
240shmdt(p, uap)
241 struct proc *p;
242 struct shmdt_args *uap;
243{
244 struct shmmap_state *shmmap_s;
245 int i;
243 int error;
246 int error = 0;
247
245 if (!jail_sysvipc_allowed && jailed(p->p_ucred))
246 return (ENOSYS);
248 mtx_lock(&Giant);
249
250 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) {
251 error = ENOSYS;
252 goto done2;
253 }
254
255 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
249 if (shmmap_s == NULL)
250 return EINVAL;
251 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
256 if (shmmap_s == NULL) {
257 error = EINVAL;
258 goto done2;
259 }
260 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
261 if (shmmap_s->shmid != -1 &&
253 shmmap_s->va == (vm_offset_t)uap->shmaddr)
262 shmmap_s->va == (vm_offset_t)uap->shmaddr) {
263 break;
255 if (i == shminfo.shmseg)
256 return EINVAL;
264 }
265 }
266 if (i == shminfo.shmseg) {
267 error = EINVAL;
268 goto done2;
269 }
270 error = shm_delete_mapping(p, shmmap_s);
258 return error;
271done2:
272 mtx_unlock(&Giant);
273 return (error);
274}
275
276#ifndef _SYS_SYSPROTO_H_
277struct shmat_args {
278 int shmid;
279 void *shmaddr;
280 int shmflg;
281};
282#endif
283
284/*
285 * MPSAFE
286 */
287int
288shmat(p, uap)
289 struct proc *p;
290 struct shmat_args *uap;
291{
274 int error, i, flags;
292 int i, flags;
293 struct shmid_ds *shmseg;
294 struct shmmap_state *shmmap_s = NULL;
295 struct shm_handle *shm_handle;
296 vm_offset_t attach_va;
297 vm_prot_t prot;
298 vm_size_t size;
299 int rv;
300 int error = 0;
301
283 GIANT_REQUIRED;
302 mtx_lock(&Giant);
303
285 if (!jail_sysvipc_allowed && jailed(p->p_ucred))
286 return (ENOSYS);
304 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) {
305 error = ENOSYS;
306 goto done2;
307 }
308
309 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
310 if (shmmap_s == NULL) {
311 size = shminfo.shmseg * sizeof(struct shmmap_state);
312 shmmap_s = malloc(size, M_SHM, M_WAITOK);
313 for (i = 0; i < shminfo.shmseg; i++)
314 shmmap_s[i].shmid = -1;
315 p->p_vmspace->vm_shm = (caddr_t)shmmap_s;
316 }
317 shmseg = shm_find_segment_by_shmid(uap->shmid);
297 if (shmseg == NULL)
298 return EINVAL;
318 if (shmseg == NULL) {
319 error = EINVAL;
320 goto done2;
321 }
322 error = ipcperm(p, &shmseg->shm_perm,
323 (uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
324 if (error)
302 return error;
325 goto done2;
326 for (i = 0; i < shminfo.shmseg; i++) {
327 if (shmmap_s->shmid == -1)
328 break;
329 shmmap_s++;
330 }
308 if (i >= shminfo.shmseg)
309 return EMFILE;
331 if (i >= shminfo.shmseg) {
332 error = EMFILE;
333 goto done2;
334 }
335 size = round_page(shmseg->shm_segsz);
336#ifdef VM_PROT_READ_IS_EXEC
337 prot = VM_PROT_READ | VM_PROT_EXECUTE;
338#else
339 prot = VM_PROT_READ;
340#endif
341 if ((uap->shmflg & SHM_RDONLY) == 0)
342 prot |= VM_PROT_WRITE;
343 flags = MAP_ANON | MAP_SHARED;
344 if (uap->shmaddr) {
345 flags |= MAP_FIXED;
321 if (uap->shmflg & SHM_RND)
346 if (uap->shmflg & SHM_RND) {
347 attach_va = (vm_offset_t)uap->shmaddr & ~(SHMLBA-1);
323 else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0)
348 } else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0) {
349 attach_va = (vm_offset_t)uap->shmaddr;
325 else
326 return EINVAL;
350 } else {
351 error = EINVAL;
352 goto done2;
353 }
354 } else {
355 /*
356 * This is just a hint to vm_map_find() about where to
357 * put it.
358 */
359 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_taddr
360 + MAXTSIZ + MAXDSIZ);
361 }
362
363 shm_handle = shmseg->shm_internal;
364 vm_object_reference(shm_handle->shm_object);
365 rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object,
366 0, &attach_va, size, (flags & MAP_FIXED)?0:1, prot, prot, 0);
367 if (rv != KERN_SUCCESS) {
341 return ENOMEM;
368 error = ENOMEM;
369 goto done2;
370 }
371 vm_map_inherit(&p->p_vmspace->vm_map,
372 attach_va, attach_va + size, VM_INHERIT_SHARE);
373
374 shmmap_s->va = attach_va;
375 shmmap_s->shmid = uap->shmid;
376 shmseg->shm_lpid = p->p_pid;
377 shmseg->shm_atime = time_second;
378 shmseg->shm_nattch++;
379 p->p_retval[0] = attach_va;
352 return 0;
380done2:
381 mtx_unlock(&Giant);
382 return (error);
383}
384
385struct oshmid_ds {
386 struct ipc_perm shm_perm; /* operation perms */
387 int shm_segsz; /* size of segment (bytes) */
388 ushort shm_cpid; /* pid, creator */
389 ushort shm_lpid; /* pid, last operation */
390 short shm_nattch; /* no. of current attaches */
391 time_t shm_atime; /* last attach time */
392 time_t shm_dtime; /* last detach time */
393 time_t shm_ctime; /* last change time */
394 void *shm_handle; /* internal handle for shm segment */
395};
396
397struct oshmctl_args {
398 int shmid;
399 int cmd;
400 struct oshmid_ds *ubuf;
401};
402
403/*
404 * MPSAFE
405 */
406static int
407oshmctl(p, uap)
408 struct proc *p;
409 struct oshmctl_args *uap;
410{
411#ifdef COMPAT_43
379 int error;
412 int error = 0;
413 struct shmid_ds *shmseg;
414 struct oshmid_ds outbuf;
415
383 if (!jail_sysvipc_allowed && jailed(p->p_ucred))
384 return (ENOSYS);
416 mtx_lock(&Giant);
417
418 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) {
419 error = ENOSYS;
420 goto done2;
421 }
422
423 shmseg = shm_find_segment_by_shmid(uap->shmid);
387 if (shmseg == NULL)
388 return EINVAL;
424 if (shmseg == NULL) {
425 error = EINVAL;
426 goto done2;
427 }
428 switch (uap->cmd) {
429 case IPC_STAT:
430 error = ipcperm(p, &shmseg->shm_perm, IPC_R);
431 if (error)
393 return error;
432 goto done2;
433 outbuf.shm_perm = shmseg->shm_perm;
434 outbuf.shm_segsz = shmseg->shm_segsz;
435 outbuf.shm_cpid = shmseg->shm_cpid;
436 outbuf.shm_lpid = shmseg->shm_lpid;
437 outbuf.shm_nattch = shmseg->shm_nattch;
438 outbuf.shm_atime = shmseg->shm_atime;
439 outbuf.shm_dtime = shmseg->shm_dtime;
440 outbuf.shm_ctime = shmseg->shm_ctime;
441 outbuf.shm_handle = shmseg->shm_internal;
442 error = copyout((caddr_t)&outbuf, uap->ubuf, sizeof(outbuf));
443 if (error)
405 return error;
444 goto done2;
445 break;
446 default:
447 /* XXX casting to (sy_call_t *) is bogus, as usual. */
409 return ((sy_call_t *)shmctl)(p, uap);
448 error = ((sy_call_t *)shmctl)(p, uap);
449 break;
450 }
411 return 0;
451done2:
452 mtx_unlock(&Giant);
453 return (error);
454#else
455 return EINVAL;
456#endif
457}
458
459#ifndef _SYS_SYSPROTO_H_
460struct shmctl_args {
461 int shmid;
462 int cmd;
463 struct shmid_ds *buf;
464};
465#endif
466
467/*
468 * MPSAFE
469 */
470int
471shmctl(p, uap)
472 struct proc *p;
473 struct shmctl_args *uap;
474{
430 int error;
475 int error = 0;
476 struct shmid_ds inbuf;
477 struct shmid_ds *shmseg;
478
434 GIANT_REQUIRED;
479 mtx_lock(&Giant);
480
436 if (!jail_sysvipc_allowed && jailed(p->p_ucred))
437 return (ENOSYS);
481 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) {
482 error = ENOSYS;
483 goto done2;
484 }
485
486 shmseg = shm_find_segment_by_shmid(uap->shmid);
440 if (shmseg == NULL)
441 return EINVAL;
487 if (shmseg == NULL) {
488 error = EINVAL;
489 goto done2;
490 }
491 switch (uap->cmd) {
492 case IPC_STAT:
493 error = ipcperm(p, &shmseg->shm_perm, IPC_R);
494 if (error)
446 return error;
495 goto done2;
496 error = copyout((caddr_t)shmseg, uap->buf, sizeof(inbuf));
497 if (error)
449 return error;
498 goto done2;
499 break;
500 case IPC_SET:
501 error = ipcperm(p, &shmseg->shm_perm, IPC_M);
502 if (error)
454 return error;
503 goto done2;
504 error = copyin(uap->buf, (caddr_t)&inbuf, sizeof(inbuf));
505 if (error)
457 return error;
506 goto done2;
507 shmseg->shm_perm.uid = inbuf.shm_perm.uid;
508 shmseg->shm_perm.gid = inbuf.shm_perm.gid;
509 shmseg->shm_perm.mode =
510 (shmseg->shm_perm.mode & ~ACCESSPERMS) |
511 (inbuf.shm_perm.mode & ACCESSPERMS);
512 shmseg->shm_ctime = time_second;
513 break;
514 case IPC_RMID:
515 error = ipcperm(p, &shmseg->shm_perm, IPC_M);
516 if (error)
468 return error;
517 goto done2;
518 shmseg->shm_perm.key = IPC_PRIVATE;
519 shmseg->shm_perm.mode |= SHMSEG_REMOVED;
520 if (shmseg->shm_nattch <= 0) {
521 shm_deallocate_segment(shmseg);
522 shm_last_free = IPCID_TO_IX(uap->shmid);
523 }
524 break;
525#if 0
526 case SHM_LOCK:
527 case SHM_UNLOCK:
528#endif
529 default:
481 return EINVAL;
530 error = EINVAL;
531 break;
532 }
483 return 0;
533done2:
534 mtx_unlock(&Giant);
535 return (error);
536}
537
538#ifndef _SYS_SYSPROTO_H_
539struct shmget_args {
540 key_t key;
541 size_t size;
542 int shmflg;
543};
544#endif
545
546static int
547shmget_existing(p, uap, mode, segnum)
548 struct proc *p;
549 struct shmget_args *uap;
550 int mode;
551 int segnum;
552{
553 struct shmid_ds *shmseg;
554 int error;
555
556 shmseg = &shmsegs[segnum];
557 if (shmseg->shm_perm.mode & SHMSEG_REMOVED) {
558 /*
559 * This segment is in the process of being allocated. Wait
560 * until it's done, and look the key up again (in case the
561 * allocation failed or it was freed).
562 */
563 shmseg->shm_perm.mode |= SHMSEG_WANTED;
564 error = tsleep((caddr_t)shmseg, PLOCK | PCATCH, "shmget", 0);
565 if (error)
566 return error;
567 return EAGAIN;
568 }
569 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
570 return EEXIST;
571 error = ipcperm(p, &shmseg->shm_perm, mode);
572 if (error)
573 return error;
574 if (uap->size && uap->size > shmseg->shm_segsz)
575 return EINVAL;
576 p->p_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
577 return 0;
578}
579
580static int
581shmget_allocate_segment(p, uap, mode)
582 struct proc *p;
583 struct shmget_args *uap;
584 int mode;
585{
586 int i, segnum, shmid, size;
587 struct ucred *cred = p->p_ucred;
588 struct shmid_ds *shmseg;
589 struct shm_handle *shm_handle;
590
591 GIANT_REQUIRED;
592
593 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
594 return EINVAL;
595 if (shm_nused >= shminfo.shmmni) /* Any shmids left? */
596 return ENOSPC;
597 size = round_page(uap->size);
598 if (shm_committed + btoc(size) > shminfo.shmall)
599 return ENOMEM;
600 if (shm_last_free < 0) {
601 shmrealloc(); /* Maybe expand the shmsegs[] array. */
602 for (i = 0; i < shmalloced; i++)
603 if (shmsegs[i].shm_perm.mode & SHMSEG_FREE)
604 break;
605 if (i == shmalloced)
606 return ENOSPC;
607 segnum = i;
608 } else {
609 segnum = shm_last_free;
610 shm_last_free = -1;
611 }
612 shmseg = &shmsegs[segnum];
613 /*
614 * In case we sleep in malloc(), mark the segment present but deleted
615 * so that noone else tries to create the same key.
616 */
617 shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED;
618 shmseg->shm_perm.key = uap->key;
619 shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff;
620 shm_handle = (struct shm_handle *)
621 malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK);
622 shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
623
624 /*
625 * We make sure that we have allocated a pager before we need
626 * to.
627 */
628 if (shm_use_phys) {
629 shm_handle->shm_object =
630 vm_pager_allocate(OBJT_PHYS, 0, size, VM_PROT_DEFAULT, 0);
631 } else {
632 shm_handle->shm_object =
633 vm_pager_allocate(OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0);
634 }
635 vm_object_clear_flag(shm_handle->shm_object, OBJ_ONEMAPPING);
636 vm_object_set_flag(shm_handle->shm_object, OBJ_NOSPLIT);
637
638 shmseg->shm_internal = shm_handle;
639 shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid;
640 shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid;
641 shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) |
642 (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
643 shmseg->shm_segsz = uap->size;
644 shmseg->shm_cpid = p->p_pid;
645 shmseg->shm_lpid = shmseg->shm_nattch = 0;
646 shmseg->shm_atime = shmseg->shm_dtime = 0;
647 shmseg->shm_ctime = time_second;
648 shm_committed += btoc(size);
649 shm_nused++;
650 if (shmseg->shm_perm.mode & SHMSEG_WANTED) {
651 /*
652 * Somebody else wanted this key while we were asleep. Wake
653 * them up now.
654 */
655 shmseg->shm_perm.mode &= ~SHMSEG_WANTED;
656 wakeup((caddr_t)shmseg);
657 }
658 p->p_retval[0] = shmid;
659 return 0;
660}
661
662/*
663 * MPSAFE
664 */
665int
666shmget(p, uap)
667 struct proc *p;
668 struct shmget_args *uap;
669{
615 int segnum, mode, error;
670 int segnum, mode;
671 int error;
672
617 if (!jail_sysvipc_allowed && jailed(p->p_ucred))
618 return (ENOSYS);
673 mtx_lock(&Giant);
674
675 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) {
676 error = ENOSYS;
677 goto done2;
678 }
679
680 mode = uap->shmflg & ACCESSPERMS;
681 if (uap->key != IPC_PRIVATE) {
682 again:
683 segnum = shm_find_segment_by_key(uap->key);
684 if (segnum >= 0) {
685 error = shmget_existing(p, uap, mode, segnum);
686 if (error == EAGAIN)
687 goto again;
628 return error;
688 goto done2;
689 }
630 if ((uap->shmflg & IPC_CREAT) == 0)
631 return ENOENT;
690 if ((uap->shmflg & IPC_CREAT) == 0) {
691 error = ENOENT;
692 goto done2;
693 }
694 }
633 return shmget_allocate_segment(p, uap, mode);
695 error = shmget_allocate_segment(p, uap, mode);
696done2:
697 mtx_unlock(&Giant);
698 return (error);
699}
700
701/*
702 * MPSAFE
703 */
704int
705shmsys(p, uap)
706 struct proc *p;
707 /* XXX actually varargs. */
708 struct shmsys_args /* {
709 u_int which;
710 int a2;
711 int a3;
712 int a4;
713 } */ *uap;
714{
715 int error;
716
648 if (!jail_sysvipc_allowed && jailed(p->p_ucred))
649 return (ENOSYS);
717 mtx_lock(&Giant);
718
651 if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
652 return EINVAL;
653 return ((*shmcalls[uap->which])(p, &uap->a2));
719 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) {
720 error = ENOSYS;
721 goto done2;
722 }
723
724 if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0])) {
725 error = EINVAL;
726 goto done2;
727 }
728 error = (*shmcalls[uap->which])(p, &uap->a2);
729done2:
730 mtx_unlock(&Giant);
731 return (error);
732}
733
734static void
735shmfork_myhook(p1, p2)
736 struct proc *p1, *p2;
737{
738 struct shmmap_state *shmmap_s;
739 size_t size;
740 int i;
741
742 size = shminfo.shmseg * sizeof(struct shmmap_state);
743 shmmap_s = malloc(size, M_SHM, M_WAITOK);
744 bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmmap_s, size);
745 p2->p_vmspace->vm_shm = (caddr_t)shmmap_s;
746 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
747 if (shmmap_s->shmid != -1)
748 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].shm_nattch++;
749}
750
751static void
752shmexit_myhook(p)
753 struct proc *p;
754{
755 struct shmmap_state *shmmap_s;
756 int i;
757
758 GIANT_REQUIRED;
759
760 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
761 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
762 if (shmmap_s->shmid != -1)
763 shm_delete_mapping(p, shmmap_s);
764 free((caddr_t)p->p_vmspace->vm_shm, M_SHM);
765 p->p_vmspace->vm_shm = NULL;
766}
767
768static void
769shmrealloc(void)
770{
771 int i;
772 struct shmid_ds *newsegs;
773
774 if (shmalloced >= shminfo.shmmni)
775 return;
776
777 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK);
778 if (newsegs == NULL)
779 return;
780 for (i = 0; i < shmalloced; i++)
781 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
782 for (; i < shminfo.shmmni; i++) {
783 shmsegs[i].shm_perm.mode = SHMSEG_FREE;
784 shmsegs[i].shm_perm.seq = 0;
785 }
786 free(shmsegs, M_SHM);
787 shmsegs = newsegs;
788 shmalloced = shminfo.shmmni;
789}
790
791static void
792shminit()
793{
794 int i;
795
796 shmalloced = shminfo.shmmni;
797 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK);
798 if (shmsegs == NULL)
799 panic("cannot allocate initial memory for sysvshm");
800 for (i = 0; i < shmalloced; i++) {
801 shmsegs[i].shm_perm.mode = SHMSEG_FREE;
802 shmsegs[i].shm_perm.seq = 0;
803 }
804 shm_last_free = 0;
805 shm_nused = 0;
806 shm_committed = 0;
807 shmexit_hook = &shmexit_myhook;
808 shmfork_hook = &shmfork_myhook;
809}
810
811static int
812shmunload()
813{
814
815 if (shm_nused > 0)
816 return (EBUSY);
817
818 free(shmsegs, M_SHM);
819 shmexit_hook = NULL;
820 shmfork_hook = NULL;
821 return (0);
822}
823
824static int
825sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
826{
827
828 return (SYSCTL_OUT(req, shmsegs, shmalloced * sizeof(shmsegs[0])));
829}
830
831static int
832sysvshm_modload(struct module *module, int cmd, void *arg)
833{
834 int error = 0;
835
836 switch (cmd) {
837 case MOD_LOAD:
838 shminit();
839 break;
840 case MOD_UNLOAD:
841 error = shmunload();
842 break;
843 case MOD_SHUTDOWN:
844 break;
845 default:
846 error = EINVAL;
847 break;
848 }
849 return (error);
850}
851
852static moduledata_t sysvshm_mod = {
853 "sysvshm",
854 &sysvshm_modload,
855 NULL
856};
857
858SYSCALL_MODULE_HELPER(shmsys, 4);
859SYSCALL_MODULE_HELPER(shmat, 3);
860SYSCALL_MODULE_HELPER(shmctl, 3);
861SYSCALL_MODULE_HELPER(shmdt, 1);
862SYSCALL_MODULE_HELPER(shmget, 3);
863
864DECLARE_MODULE(sysvshm, sysvshm_mod,
865 SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
866MODULE_VERSION(sysvshm, 1);