FreeBSD/Linux Kernel Cross Reference
sys/kern/sysv_shm.c
1 /* $FreeBSD$ */
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_sysvipc.h"
36
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/sysproto.h>
40 #include <sys/kernel.h>
41 #include <sys/sysctl.h>
42 #include <sys/shm.h>
43 #include <sys/proc.h>
44 #include <sys/malloc.h>
45 #include <sys/mman.h>
46 #include <sys/stat.h>
47 #include <sys/sysent.h>
48 #include <sys/jail.h>
49
50 #include <vm/vm.h>
51 #include <vm/vm_param.h>
52 #include <sys/lock.h>
53 #include <vm/pmap.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_map.h>
56 #include <vm/vm_page.h>
57 #include <vm/vm_pager.h>
58
59 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
60
61 struct oshmctl_args;
62 static int oshmctl __P((struct proc *p, struct oshmctl_args *uap));
63
64 static int shmget_allocate_segment __P((struct proc *p, struct shmget_args *uap, int mode));
65 static int shmget_existing __P((struct proc *p, struct shmget_args *uap, int mode, int segnum));
66
67 /* XXX casting to (sy_call_t *) is bogus, as usual. */
68 static sy_call_t *shmcalls[] = {
69 (sy_call_t *)shmat, (sy_call_t *)oshmctl,
70 (sy_call_t *)shmdt, (sy_call_t *)shmget,
71 (sy_call_t *)shmctl
72 };
73
74 #define SHMSEG_FREE 0x0200
75 #define SHMSEG_REMOVED 0x0400
76 #define SHMSEG_ALLOCATED 0x0800
77 #define SHMSEG_WANTED 0x1000
78
79 static int shm_last_free, shm_nused, shm_committed, shmalloced;
80 static struct shmid_ds *shmsegs;
81
82 struct shm_handle {
83 /* vm_offset_t kva; */
84 vm_object_t shm_object;
85 };
86
87 struct shmmap_state {
88 vm_offset_t va;
89 int shmid;
90 };
91
92 static void shm_deallocate_segment __P((struct shmid_ds *));
93 static int shm_find_segment_by_key __P((key_t));
94 static struct shmid_ds *shm_find_segment_by_shmid __P((int));
95 static int shm_delete_mapping __P((struct proc *, struct shmmap_state *));
96 static void shmrealloc __P((void));
97 static void shminit __P((void *));
98
99 /*
100 * Tuneable values
101 */
102 #ifndef SHMMAXPGS
103 #define SHMMAXPGS 8192 /* note: sysv shared memory is swap backed */
104 #endif
105 #ifndef SHMMAX
106 #define SHMMAX (SHMMAXPGS*PAGE_SIZE)
107 #endif
108 #ifndef SHMMIN
109 #define SHMMIN 1
110 #endif
111 #ifndef SHMMNI
112 #define SHMMNI 192
113 #endif
114 #ifndef SHMSEG
115 #define SHMSEG 128
116 #endif
117 #ifndef SHMALL
118 #define SHMALL (SHMMAXPGS)
119 #endif
120
121 struct shminfo shminfo = {
122 SHMMAX,
123 SHMMIN,
124 SHMMNI,
125 SHMSEG,
126 SHMALL
127 };
128
129 static int shm_use_phys;
130 static int shm_allow_removed;
131
132 TUNABLE_INT("kern.ipc.shmmin", &shminfo.shmmin);
133 TUNABLE_INT("kern.ipc.shmmni", &shminfo.shmmni);
134 TUNABLE_INT("kern.ipc.shmseg", &shminfo.shmseg);
135 TUNABLE_INT("kern.ipc.shmmaxpgs", &shminfo.shmall);
136 TUNABLE_INT("kern.ipc.shm_use_phys", &shm_use_phys);
137
138 SYSCTL_DECL(_kern_ipc);
139 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0, "");
140 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0, "");
141 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RD, &shminfo.shmmni, 0, "");
142 SYSCTL_INT(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RW, &shminfo.shmseg, 0, "");
143 SYSCTL_INT(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0, "");
144 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW, &shm_use_phys, 0, "");
145 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RW, &shm_allow_removed, 0, "");
146
147 static int
148 shm_find_segment_by_key(key)
149 key_t key;
150 {
151 int i;
152
153 for (i = 0; i < shmalloced; i++)
154 if ((shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED) &&
155 shmsegs[i].shm_perm.key == key)
156 return i;
157 return -1;
158 }
159
160 static struct shmid_ds *
161 shm_find_segment_by_shmid(shmid)
162 int shmid;
163 {
164 int segnum;
165 struct shmid_ds *shmseg;
166
167 segnum = IPCID_TO_IX(shmid);
168 if (segnum < 0 || segnum >= shmalloced)
169 return NULL;
170 shmseg = &shmsegs[segnum];
171 if ((shmseg->shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
172 (!shm_allow_removed &&
173 (shmseg->shm_perm.mode & SHMSEG_REMOVED) != 0) ||
174 shmseg->shm_perm.seq != IPCID_TO_SEQ(shmid))
175 return NULL;
176 return shmseg;
177 }
178
179 static void
180 shm_deallocate_segment(shmseg)
181 struct shmid_ds *shmseg;
182 {
183 struct shm_handle *shm_handle;
184 size_t size;
185
186 shm_handle = shmseg->shm_internal;
187 vm_object_deallocate(shm_handle->shm_object);
188 free((caddr_t)shm_handle, M_SHM);
189 shmseg->shm_internal = NULL;
190 size = round_page(shmseg->shm_segsz);
191 shm_committed -= btoc(size);
192 shm_nused--;
193 shmseg->shm_perm.mode = SHMSEG_FREE;
194 }
195
196 static int
197 shm_delete_mapping(p, shmmap_s)
198 struct proc *p;
199 struct shmmap_state *shmmap_s;
200 {
201 struct shmid_ds *shmseg;
202 int segnum, result;
203 size_t size;
204
205 segnum = IPCID_TO_IX(shmmap_s->shmid);
206 shmseg = &shmsegs[segnum];
207 size = round_page(shmseg->shm_segsz);
208 result = vm_map_remove(&p->p_vmspace->vm_map, shmmap_s->va, shmmap_s->va + size);
209 if (result != KERN_SUCCESS)
210 return EINVAL;
211 shmmap_s->shmid = -1;
212 shmseg->shm_dtime = time_second;
213 if ((--shmseg->shm_nattch <= 0) &&
214 (shmseg->shm_perm.mode & SHMSEG_REMOVED)) {
215 shm_deallocate_segment(shmseg);
216 shm_last_free = segnum;
217 }
218 return 0;
219 }
220
221 #ifndef _SYS_SYSPROTO_H_
222 struct shmdt_args {
223 void *shmaddr;
224 };
225 #endif
226
227 int
228 shmdt(p, uap)
229 struct proc *p;
230 struct shmdt_args *uap;
231 {
232 struct shmmap_state *shmmap_s;
233 int i;
234
235 if (!jail_sysvipc_allowed && p->p_prison != NULL)
236 return (ENOSYS);
237
238 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
239 if (shmmap_s == NULL)
240 return EINVAL;
241 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
242 if (shmmap_s->shmid != -1 &&
243 shmmap_s->va == (vm_offset_t)uap->shmaddr)
244 break;
245 if (i == shminfo.shmseg)
246 return EINVAL;
247 return shm_delete_mapping(p, shmmap_s);
248 }
249
250 #ifndef _SYS_SYSPROTO_H_
251 struct shmat_args {
252 int shmid;
253 void *shmaddr;
254 int shmflg;
255 };
256 #endif
257
258 int
259 shmat(p, uap)
260 struct proc *p;
261 struct shmat_args *uap;
262 {
263 int error, i, flags;
264 struct shmid_ds *shmseg;
265 struct shmmap_state *shmmap_s = NULL;
266 struct shm_handle *shm_handle;
267 vm_offset_t attach_va;
268 vm_prot_t prot;
269 vm_size_t size;
270 int rv;
271
272 if (!jail_sysvipc_allowed && p->p_prison != NULL)
273 return (ENOSYS);
274
275 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
276 if (shmmap_s == NULL) {
277 size = shminfo.shmseg * sizeof(struct shmmap_state);
278 shmmap_s = malloc(size, M_SHM, M_WAITOK);
279 for (i = 0; i < shminfo.shmseg; i++)
280 shmmap_s[i].shmid = -1;
281 p->p_vmspace->vm_shm = (caddr_t)shmmap_s;
282 }
283 shmseg = shm_find_segment_by_shmid(uap->shmid);
284 if (shmseg == NULL)
285 return EINVAL;
286 error = ipcperm(p, &shmseg->shm_perm,
287 (uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
288 if (error)
289 return error;
290 for (i = 0; i < shminfo.shmseg; i++) {
291 if (shmmap_s->shmid == -1)
292 break;
293 shmmap_s++;
294 }
295 if (i >= shminfo.shmseg)
296 return EMFILE;
297 size = round_page(shmseg->shm_segsz);
298 #ifdef VM_PROT_READ_IS_EXEC
299 prot = VM_PROT_READ | VM_PROT_EXECUTE;
300 #else
301 prot = VM_PROT_READ;
302 #endif
303 if ((uap->shmflg & SHM_RDONLY) == 0)
304 prot |= VM_PROT_WRITE;
305 flags = MAP_ANON | MAP_SHARED;
306 if (uap->shmaddr) {
307 flags |= MAP_FIXED;
308 if (uap->shmflg & SHM_RND)
309 attach_va = (vm_offset_t)uap->shmaddr & ~(SHMLBA-1);
310 else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0)
311 attach_va = (vm_offset_t)uap->shmaddr;
312 else
313 return EINVAL;
314 } else {
315 /* This is just a hint to vm_map_find() about where to put it. */
316 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_taddr + maxtsiz + maxdsiz);
317 }
318
319 shm_handle = shmseg->shm_internal;
320 vm_object_reference(shm_handle->shm_object);
321 rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object,
322 0, &attach_va, size, (flags & MAP_FIXED)?0:1, prot, prot, 0);
323 if (rv != KERN_SUCCESS) {
324 vm_object_deallocate(shm_handle->shm_object);
325 return ENOMEM;
326 }
327 vm_map_inherit(&p->p_vmspace->vm_map,
328 attach_va, attach_va + size, VM_INHERIT_SHARE);
329
330 shmmap_s->va = attach_va;
331 shmmap_s->shmid = uap->shmid;
332 shmseg->shm_lpid = p->p_pid;
333 shmseg->shm_atime = time_second;
334 shmseg->shm_nattch++;
335 p->p_retval[0] = attach_va;
336 return 0;
337 }
338
339 struct oshmid_ds {
340 struct ipc_perm shm_perm; /* operation perms */
341 int shm_segsz; /* size of segment (bytes) */
342 ushort shm_cpid; /* pid, creator */
343 ushort shm_lpid; /* pid, last operation */
344 short shm_nattch; /* no. of current attaches */
345 time_t shm_atime; /* last attach time */
346 time_t shm_dtime; /* last detach time */
347 time_t shm_ctime; /* last change time */
348 void *shm_handle; /* internal handle for shm segment */
349 };
350
351 struct oshmctl_args {
352 int shmid;
353 int cmd;
354 struct oshmid_ds *ubuf;
355 };
356
357 static int
358 oshmctl(p, uap)
359 struct proc *p;
360 struct oshmctl_args *uap;
361 {
362 #ifdef COMPAT_43
363 int error;
364 struct shmid_ds *shmseg;
365 struct oshmid_ds outbuf;
366
367 if (!jail_sysvipc_allowed && p->p_prison != NULL)
368 return (ENOSYS);
369
370 shmseg = shm_find_segment_by_shmid(uap->shmid);
371 if (shmseg == NULL)
372 return EINVAL;
373 switch (uap->cmd) {
374 case IPC_STAT:
375 error = ipcperm(p, &shmseg->shm_perm, IPC_R);
376 if (error)
377 return error;
378 outbuf.shm_perm = shmseg->shm_perm;
379 outbuf.shm_segsz = shmseg->shm_segsz;
380 outbuf.shm_cpid = shmseg->shm_cpid;
381 outbuf.shm_lpid = shmseg->shm_lpid;
382 outbuf.shm_nattch = shmseg->shm_nattch;
383 outbuf.shm_atime = shmseg->shm_atime;
384 outbuf.shm_dtime = shmseg->shm_dtime;
385 outbuf.shm_ctime = shmseg->shm_ctime;
386 outbuf.shm_handle = shmseg->shm_internal;
387 error = copyout((caddr_t)&outbuf, uap->ubuf, sizeof(outbuf));
388 if (error)
389 return error;
390 break;
391 default:
392 /* XXX casting to (sy_call_t *) is bogus, as usual. */
393 return ((sy_call_t *)shmctl)(p, uap);
394 }
395 return 0;
396 #else
397 return EINVAL;
398 #endif
399 }
400
401 #ifndef _SYS_SYSPROTO_H_
402 struct shmctl_args {
403 int shmid;
404 int cmd;
405 struct shmid_ds *buf;
406 };
407 #endif
408
409 int
410 shmctl(p, uap)
411 struct proc *p;
412 struct shmctl_args *uap;
413 {
414 int error;
415 struct shmid_ds inbuf;
416 struct shmid_ds *shmseg;
417
418 if (!jail_sysvipc_allowed && p->p_prison != NULL)
419 return (ENOSYS);
420
421 shmseg = shm_find_segment_by_shmid(uap->shmid);
422 if (shmseg == NULL)
423 return EINVAL;
424 switch (uap->cmd) {
425 case IPC_STAT:
426 error = ipcperm(p, &shmseg->shm_perm, IPC_R);
427 if (error)
428 return error;
429 error = copyout((caddr_t)shmseg, uap->buf, sizeof(inbuf));
430 if (error)
431 return error;
432 break;
433 case IPC_SET:
434 error = ipcperm(p, &shmseg->shm_perm, IPC_M);
435 if (error)
436 return error;
437 error = copyin(uap->buf, (caddr_t)&inbuf, sizeof(inbuf));
438 if (error)
439 return error;
440 shmseg->shm_perm.uid = inbuf.shm_perm.uid;
441 shmseg->shm_perm.gid = inbuf.shm_perm.gid;
442 shmseg->shm_perm.mode =
443 (shmseg->shm_perm.mode & ~ACCESSPERMS) |
444 (inbuf.shm_perm.mode & ACCESSPERMS);
445 shmseg->shm_ctime = time_second;
446 break;
447 case IPC_RMID:
448 error = ipcperm(p, &shmseg->shm_perm, IPC_M);
449 if (error)
450 return error;
451 shmseg->shm_perm.key = IPC_PRIVATE;
452 shmseg->shm_perm.mode |= SHMSEG_REMOVED;
453 if (shmseg->shm_nattch <= 0) {
454 shm_deallocate_segment(shmseg);
455 shm_last_free = IPCID_TO_IX(uap->shmid);
456 }
457 break;
458 #if 0
459 case SHM_LOCK:
460 case SHM_UNLOCK:
461 #endif
462 default:
463 return EINVAL;
464 }
465 return 0;
466 }
467
468 #ifndef _SYS_SYSPROTO_H_
469 struct shmget_args {
470 key_t key;
471 size_t size;
472 int shmflg;
473 };
474 #endif
475
476 static int
477 shmget_existing(p, uap, mode, segnum)
478 struct proc *p;
479 struct shmget_args *uap;
480 int mode;
481 int segnum;
482 {
483 struct shmid_ds *shmseg;
484 int error;
485
486 shmseg = &shmsegs[segnum];
487 if (shmseg->shm_perm.mode & SHMSEG_REMOVED) {
488 /*
489 * This segment is in the process of being allocated. Wait
490 * until it's done, and look the key up again (in case the
491 * allocation failed or it was freed).
492 */
493 shmseg->shm_perm.mode |= SHMSEG_WANTED;
494 error = tsleep((caddr_t)shmseg, PLOCK | PCATCH, "shmget", 0);
495 if (error)
496 return error;
497 return EAGAIN;
498 }
499 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
500 return EEXIST;
501 error = ipcperm(p, &shmseg->shm_perm, mode);
502 if (error)
503 return error;
504 if (uap->size && uap->size > shmseg->shm_segsz)
505 return EINVAL;
506 p->p_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
507 return 0;
508 }
509
510 static int
511 shmget_allocate_segment(p, uap, mode)
512 struct proc *p;
513 struct shmget_args *uap;
514 int mode;
515 {
516 int i, segnum, shmid, size;
517 struct ucred *cred = p->p_ucred;
518 struct shmid_ds *shmseg;
519 struct shm_handle *shm_handle;
520
521 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
522 return EINVAL;
523 if (shm_nused >= shminfo.shmmni) /* any shmids left? */
524 return ENOSPC;
525 size = round_page(uap->size);
526 if (shm_committed + btoc(size) > shminfo.shmall)
527 return ENOMEM;
528 if (shm_last_free < 0) {
529 shmrealloc(); /* maybe expand the shmsegs[] array */
530 for (i = 0; i < shmalloced; i++)
531 if (shmsegs[i].shm_perm.mode & SHMSEG_FREE)
532 break;
533 if (i == shmalloced)
534 return ENOSPC;
535 segnum = i;
536 } else {
537 segnum = shm_last_free;
538 shm_last_free = -1;
539 }
540 shmseg = &shmsegs[segnum];
541 /*
542 * In case we sleep in malloc(), mark the segment present but deleted
543 * so that noone else tries to create the same key.
544 */
545 shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED;
546 shmseg->shm_perm.key = uap->key;
547 shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff;
548 shm_handle = (struct shm_handle *)
549 malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK);
550 shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
551
552 /*
553 * We make sure that we have allocated a pager before we need
554 * to.
555 */
556 if (shm_use_phys) {
557 shm_handle->shm_object =
558 vm_pager_allocate(OBJT_PHYS, 0, size, VM_PROT_DEFAULT, 0);
559 } else {
560 shm_handle->shm_object =
561 vm_pager_allocate(OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0);
562 }
563 vm_object_clear_flag(shm_handle->shm_object, OBJ_ONEMAPPING);
564 vm_object_set_flag(shm_handle->shm_object, OBJ_NOSPLIT);
565
566 shmseg->shm_internal = shm_handle;
567 shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid;
568 shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid;
569 shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) |
570 (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
571 shmseg->shm_segsz = uap->size;
572 shmseg->shm_cpid = p->p_pid;
573 shmseg->shm_lpid = shmseg->shm_nattch = 0;
574 shmseg->shm_atime = shmseg->shm_dtime = 0;
575 shmseg->shm_ctime = time_second;
576 shm_committed += btoc(size);
577 shm_nused++;
578 if (shmseg->shm_perm.mode & SHMSEG_WANTED) {
579 /*
580 * Somebody else wanted this key while we were asleep. Wake
581 * them up now.
582 */
583 shmseg->shm_perm.mode &= ~SHMSEG_WANTED;
584 wakeup((caddr_t)shmseg);
585 }
586 p->p_retval[0] = shmid;
587 return 0;
588 }
589
590 int
591 shmget(p, uap)
592 struct proc *p;
593 struct shmget_args *uap;
594 {
595 int segnum, mode, error;
596
597 if (!jail_sysvipc_allowed && p->p_prison != NULL)
598 return (ENOSYS);
599
600 mode = uap->shmflg & ACCESSPERMS;
601 if (uap->key != IPC_PRIVATE) {
602 again:
603 segnum = shm_find_segment_by_key(uap->key);
604 if (segnum >= 0) {
605 error = shmget_existing(p, uap, mode, segnum);
606 if (error == EAGAIN)
607 goto again;
608 return error;
609 }
610 if ((uap->shmflg & IPC_CREAT) == 0)
611 return ENOENT;
612 }
613 return shmget_allocate_segment(p, uap, mode);
614 }
615
616 int
617 shmsys(p, uap)
618 struct proc *p;
619 /* XXX actually varargs. */
620 struct shmsys_args /* {
621 u_int which;
622 int a2;
623 int a3;
624 int a4;
625 } */ *uap;
626 {
627
628 if (!jail_sysvipc_allowed && p->p_prison != NULL)
629 return (ENOSYS);
630
631 if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
632 return EINVAL;
633 return ((*shmcalls[uap->which])(p, &uap->a2));
634 }
635
636 void
637 shmfork(p1, p2)
638 struct proc *p1, *p2;
639 {
640 struct shmmap_state *shmmap_s;
641 size_t size;
642 int i;
643
644 size = shminfo.shmseg * sizeof(struct shmmap_state);
645 shmmap_s = malloc(size, M_SHM, M_WAITOK);
646 bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmmap_s, size);
647 p2->p_vmspace->vm_shm = (caddr_t)shmmap_s;
648 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
649 if (shmmap_s->shmid != -1)
650 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].shm_nattch++;
651 }
652
653 void
654 shmexit(p)
655 struct proc *p;
656 {
657 struct shmmap_state *shmmap_s;
658 int i;
659
660 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
661 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
662 if (shmmap_s->shmid != -1)
663 shm_delete_mapping(p, shmmap_s);
664 free((caddr_t)p->p_vmspace->vm_shm, M_SHM);
665 p->p_vmspace->vm_shm = NULL;
666 }
667
668 static void
669 shmrealloc(void)
670 {
671 int i;
672 struct shmid_ds *newsegs;
673
674 if (shmalloced >= shminfo.shmmni)
675 return;
676
677 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK);
678 if (newsegs == NULL)
679 return;
680 for (i = 0; i < shmalloced; i++)
681 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
682 for (; i < shminfo.shmmni; i++) {
683 shmsegs[i].shm_perm.mode = SHMSEG_FREE;
684 shmsegs[i].shm_perm.seq = 0;
685 }
686 free(shmsegs, M_SHM);
687 shmsegs = newsegs;
688 shmalloced = shminfo.shmmni;
689 }
690
691 static void
692 shminit(dummy)
693 void *dummy;
694 {
695 int i;
696
697 shminfo.shmmax = shminfo.shmall * PAGE_SIZE;
698 shmalloced = shminfo.shmmni;
699 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK);
700 if (shmsegs == NULL)
701 panic("cannot allocate initial memory for sysvshm");
702 for (i = 0; i < shmalloced; i++) {
703 shmsegs[i].shm_perm.mode = SHMSEG_FREE;
704 shmsegs[i].shm_perm.seq = 0;
705 }
706 shm_last_free = 0;
707 shm_nused = 0;
708 shm_committed = 0;
709 }
710 SYSINIT(sysv_shm, SI_SUB_SYSV_SHM, SI_ORDER_FIRST, shminit, NULL);
Cache object: 2d1b51df6b215c6d0c17ea36bf4493cd
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