?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Fix the fix.
[dragonfly.git] / sys / kern / sysv_shm.c
blob794a0a369e55ec4880504e051e7e262aea5d2ae9
1 /* $FreeBSD: src/sys/kern/sysv_shm.c,v 1.45.2.6 2002/10/22 20:45:03 fjoe Exp $ */
2 /* $DragonFly: src/sys/kern/sysv_shm.c,v 1.20 2006/12/23 23:47:54 swildner Exp $ */
3 /* $NetBSD: sysv_shm.c,v 1.23 1994/07/04 23:25:12 glass Exp $ */
4
5 /*
6 * Copyright (c) 1994 Adam Glass and Charles Hannum. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by Adam Glass and Charles
19 * Hannum.
20 * 4. The names of the authors may not be used to endorse or promote products
21 * derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35 #include "opt_compat.h"
36 #include "opt_sysvipc.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/sysproto.h>
41 #include <sys/kernel.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/stat.h>
48 #include <sys/sysent.h>
49 #include <sys/jail.h>
50
51 #include <vm/vm.h>
52 #include <vm/vm_param.h>
53 #include <sys/lock.h>
54 #include <vm/pmap.h>
55 #include <vm/vm_object.h>
56 #include <vm/vm_map.h>
57 #include <vm/vm_page.h>
58 #include <vm/vm_pager.h>
59
60 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
61
62 struct oshmctl_args;
63 static int sys_oshmctl (struct proc *p, struct oshmctl_args *uap);
64
65 static int shmget_allocate_segment (struct proc *p, struct shmget_args *uap, int mode);
66 static int shmget_existing (struct proc *p, struct shmget_args *uap, int mode, int segnum);
67
68 /* XXX casting to (sy_call_t *) is bogus, as usual. */
69 static sy_call_t *shmcalls[] = {
70 (sy_call_t *)sys_shmat, (sy_call_t *)sys_oshmctl,
71 (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget,
72 (sy_call_t *)sys_shmctl
73 };
74
75 #define SHMSEG_FREE 0x0200
76 #define SHMSEG_REMOVED 0x0400
77 #define SHMSEG_ALLOCATED 0x0800
78 #define SHMSEG_WANTED 0x1000
79
80 static int shm_last_free, shm_nused, shm_committed, shmalloced;
81 static struct shmid_ds *shmsegs;
82
83 struct shm_handle {
84 /* vm_offset_t kva; */
85 vm_object_t shm_object;
86 };
87
88 struct shmmap_state {
89 vm_offset_t va;
90 int shmid;
91 };
92
93 static void shm_deallocate_segment (struct shmid_ds *);
94 static int shm_find_segment_by_key (key_t);
95 static struct shmid_ds *shm_find_segment_by_shmid (int);
96 static int shm_delete_mapping (struct vmspace *vm, struct shmmap_state *);
97 static void shmrealloc (void);
98 static void shminit (void *);
99
100 /*
101 * Tuneable values
102 */
103 #ifndef SHMMAXPGS
104 #define SHMMAXPGS 8192 /* note: sysv shared memory is swap backed */
105 #endif
106 #ifndef SHMMAX
107 #define SHMMAX (SHMMAXPGS*PAGE_SIZE)
108 #endif
109 #ifndef SHMMIN
110 #define SHMMIN 1
111 #endif
112 #ifndef SHMMNI
113 #define SHMMNI 192
114 #endif
115 #ifndef SHMSEG
116 #define SHMSEG 128
117 #endif
118 #ifndef SHMALL
119 #define SHMALL (SHMMAXPGS)
120 #endif
121
122 struct shminfo shminfo = {
123 SHMMAX,
124 SHMMIN,
125 SHMMNI,
126 SHMSEG,
127 SHMALL
128 };
129
130 static int shm_use_phys;
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_INT(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0, "");
139 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0, "");
140 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RD, &shminfo.shmmni, 0, "");
141 SYSCTL_INT(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RW, &shminfo.shmseg, 0, "");
142 SYSCTL_INT(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0, "");
143 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW, &shm_use_phys, 0, "");
144
145 static int
146 shm_find_segment_by_key(key_t key)
147 {
148 int i;
149
150 for (i = 0; i < shmalloced; i++)
151 if ((shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED) &&
152 shmsegs[i].shm_perm.key == key)
153 return i;
154 return -1;
155 }
156
157 static struct shmid_ds *
158 shm_find_segment_by_shmid(int shmid)
159 {
160 int segnum;
161 struct shmid_ds *shmseg;
162
163 segnum = IPCID_TO_IX(shmid);
164 if (segnum < 0 || segnum >= shmalloced)
165 return NULL;
166 shmseg = &shmsegs[segnum];
167 if ((shmseg->shm_perm.mode & (SHMSEG_ALLOCATED | SHMSEG_REMOVED))
168 != SHMSEG_ALLOCATED ||
169 shmseg->shm_perm.seq != IPCID_TO_SEQ(shmid))
170 return NULL;
171 return shmseg;
172 }
173
174 static void
175 shm_deallocate_segment(struct shmid_ds *shmseg)
176 {
177 struct shm_handle *shm_handle;
178 size_t size;
179
180 shm_handle = shmseg->shm_internal;
181 vm_object_deallocate(shm_handle->shm_object);
182 kfree((caddr_t)shm_handle, M_SHM);
183 shmseg->shm_internal = NULL;
184 size = round_page(shmseg->shm_segsz);
185 shm_committed -= btoc(size);
186 shm_nused--;
187 shmseg->shm_perm.mode = SHMSEG_FREE;
188 }
189
190 static int
191 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s)
192 {
193 struct shmid_ds *shmseg;
194 int segnum, result;
195 size_t size;
196
197 segnum = IPCID_TO_IX(shmmap_s->shmid);
198 shmseg = &shmsegs[segnum];
199 size = round_page(shmseg->shm_segsz);
200 result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size);
201 if (result != KERN_SUCCESS)
202 return EINVAL;
203 shmmap_s->shmid = -1;
204 shmseg->shm_dtime = time_second;
205 if ((--shmseg->shm_nattch <= 0) &&
206 (shmseg->shm_perm.mode & SHMSEG_REMOVED)) {
207 shm_deallocate_segment(shmseg);
208 shm_last_free = segnum;
209 }
210 return 0;
211 }
212
213 int
214 sys_shmdt(struct shmdt_args *uap)
215 {
216 struct proc *p = curproc;
217 struct shmmap_state *shmmap_s;
218 int i;
219
220 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
221 return (ENOSYS);
222
223 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
224 if (shmmap_s == NULL)
225 return EINVAL;
226 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
227 if (shmmap_s->shmid != -1 &&
228 shmmap_s->va == (vm_offset_t)uap->shmaddr)
229 break;
230 if (i == shminfo.shmseg)
231 return EINVAL;
232 return shm_delete_mapping(p->p_vmspace, shmmap_s);
233 }
234
235 int
236 sys_shmat(struct shmat_args *uap)
237 {
238 struct proc *p = curproc;
239 int error, i, flags;
240 struct shmid_ds *shmseg;
241 struct shmmap_state *shmmap_s = NULL;
242 struct shm_handle *shm_handle;
243 vm_offset_t attach_va;
244 vm_prot_t prot;
245 vm_size_t size;
246 int rv;
247
248 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
249 return (ENOSYS);
250
251 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
252 if (shmmap_s == NULL) {
253 size = shminfo.shmseg * sizeof(struct shmmap_state);
254 shmmap_s = kmalloc(size, M_SHM, M_WAITOK);
255 for (i = 0; i < shminfo.shmseg; i++)
256 shmmap_s[i].shmid = -1;
257 p->p_vmspace->vm_shm = (caddr_t)shmmap_s;
258 }
259 shmseg = shm_find_segment_by_shmid(uap->shmid);
260 if (shmseg == NULL)
261 return EINVAL;
262 error = ipcperm(p, &shmseg->shm_perm,
263 (uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
264 if (error)
265 return error;
266 for (i = 0; i < shminfo.shmseg; i++) {
267 if (shmmap_s->shmid == -1)
268 break;
269 shmmap_s++;
270 }
271 if (i >= shminfo.shmseg)
272 return EMFILE;
273 size = round_page(shmseg->shm_segsz);
274 #ifdef VM_PROT_READ_IS_EXEC
275 prot = VM_PROT_READ | VM_PROT_EXECUTE;
276 #else
277 prot = VM_PROT_READ;
278 #endif
279 if ((uap->shmflg & SHM_RDONLY) == 0)
280 prot |= VM_PROT_WRITE;
281 flags = MAP_ANON | MAP_SHARED;
282 if (uap->shmaddr) {
283 flags |= MAP_FIXED;
284 if (uap->shmflg & SHM_RND)
285 attach_va = (vm_offset_t)uap->shmaddr & ~(SHMLBA-1);
286 else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0)
287 attach_va = (vm_offset_t)uap->shmaddr;
288 else
289 return EINVAL;
290 } else {
291 /* This is just a hint to vm_map_find() about where to put it. */
292 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_taddr + maxtsiz + maxdsiz);
293 }
294
295 shm_handle = shmseg->shm_internal;
296 vm_object_reference(shm_handle->shm_object);
297 rv = vm_map_find(&p->p_vmspace->vm_map,
298 shm_handle->shm_object, 0,
299 &attach_va, size,
300 ((flags & MAP_FIXED) ? 0 : 1),
301 VM_MAPTYPE_NORMAL,
302 prot, prot,
303 0);
304 if (rv != KERN_SUCCESS) {
305 vm_object_deallocate(shm_handle->shm_object);
306 return ENOMEM;
307 }
308 vm_map_inherit(&p->p_vmspace->vm_map,
309 attach_va, attach_va + size, VM_INHERIT_SHARE);
310
311 shmmap_s->va = attach_va;
312 shmmap_s->shmid = uap->shmid;
313 shmseg->shm_lpid = p->p_pid;
314 shmseg->shm_atime = time_second;
315 shmseg->shm_nattch++;
316 uap->sysmsg_result = attach_va;
317 return 0;
318 }
319
320 struct oshmid_ds {
321 struct ipc_perm shm_perm; /* operation perms */
322 int shm_segsz; /* size of segment (bytes) */
323 ushort shm_cpid; /* pid, creator */
324 ushort shm_lpid; /* pid, last operation */
325 short shm_nattch; /* no. of current attaches */
326 time_t shm_atime; /* last attach time */
327 time_t shm_dtime; /* last detach time */
328 time_t shm_ctime; /* last change time */
329 void *shm_handle; /* internal handle for shm segment */
330 };
331
332 struct oshmctl_args {
333 struct sysmsg sysmsg;
334 int shmid;
335 int cmd;
336 struct oshmid_ds *ubuf;
337 };
338
339 static int
340 sys_oshmctl(struct proc *p, struct oshmctl_args *uap)
341 {
342 #ifdef COMPAT_43
343 int error;
344 struct shmid_ds *shmseg;
345 struct oshmid_ds outbuf;
346
347 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
348 return (ENOSYS);
349
350 shmseg = shm_find_segment_by_shmid(uap->shmid);
351 if (shmseg == NULL)
352 return EINVAL;
353 switch (uap->cmd) {
354 case IPC_STAT:
355 error = ipcperm(p, &shmseg->shm_perm, IPC_R);
356 if (error)
357 return error;
358 outbuf.shm_perm = shmseg->shm_perm;
359 outbuf.shm_segsz = shmseg->shm_segsz;
360 outbuf.shm_cpid = shmseg->shm_cpid;
361 outbuf.shm_lpid = shmseg->shm_lpid;
362 outbuf.shm_nattch = shmseg->shm_nattch;
363 outbuf.shm_atime = shmseg->shm_atime;
364 outbuf.shm_dtime = shmseg->shm_dtime;
365 outbuf.shm_ctime = shmseg->shm_ctime;
366 outbuf.shm_handle = shmseg->shm_internal;
367 error = copyout((caddr_t)&outbuf, uap->ubuf, sizeof(outbuf));
368 if (error)
369 return error;
370 break;
371 default:
372 /* XXX casting to (sy_call_t *) is bogus, as usual. */
373 return (sys_shmctl((struct shmctl_args *)uap));
374 }
375 return 0;
376 #else
377 return EINVAL;
378 #endif
379 }
380
381 int
382 sys_shmctl(struct shmctl_args *uap)
383 {
384 struct proc *p = curproc;
385 int error;
386 struct shmid_ds inbuf;
387 struct shmid_ds *shmseg;
388
389 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
390 return (ENOSYS);
391
392 shmseg = shm_find_segment_by_shmid(uap->shmid);
393 if (shmseg == NULL)
394 return EINVAL;
395 switch (uap->cmd) {
396 case IPC_STAT:
397 error = ipcperm(p, &shmseg->shm_perm, IPC_R);
398 if (error)
399 return error;
400 error = copyout((caddr_t)shmseg, uap->buf, sizeof(inbuf));
401 if (error)
402 return error;
403 break;
404 case IPC_SET:
405 error = ipcperm(p, &shmseg->shm_perm, IPC_M);
406 if (error)
407 return error;
408 error = copyin(uap->buf, (caddr_t)&inbuf, sizeof(inbuf));
409 if (error)
410 return error;
411 shmseg->shm_perm.uid = inbuf.shm_perm.uid;
412 shmseg->shm_perm.gid = inbuf.shm_perm.gid;
413 shmseg->shm_perm.mode =
414 (shmseg->shm_perm.mode & ~ACCESSPERMS) |
415 (inbuf.shm_perm.mode & ACCESSPERMS);
416 shmseg->shm_ctime = time_second;
417 break;
418 case IPC_RMID:
419 error = ipcperm(p, &shmseg->shm_perm, IPC_M);
420 if (error)
421 return error;
422 shmseg->shm_perm.key = IPC_PRIVATE;
423 shmseg->shm_perm.mode |= SHMSEG_REMOVED;
424 if (shmseg->shm_nattch <= 0) {
425 shm_deallocate_segment(shmseg);
426 shm_last_free = IPCID_TO_IX(uap->shmid);
427 }
428 break;
429 #if 0
430 case SHM_LOCK:
431 case SHM_UNLOCK:
432 #endif
433 default:
434 return EINVAL;
435 }
436 return 0;
437 }
438
439 static int
440 shmget_existing(struct proc *p, struct shmget_args *uap, int mode, int segnum)
441 {
442 struct shmid_ds *shmseg;
443 int error;
444
445 shmseg = &shmsegs[segnum];
446 if (shmseg->shm_perm.mode & SHMSEG_REMOVED) {
447 /*
448 * This segment is in the process of being allocated. Wait
449 * until it's done, and look the key up again (in case the
450 * allocation failed or it was freed).
451 */
452 shmseg->shm_perm.mode |= SHMSEG_WANTED;
453 error = tsleep((caddr_t)shmseg, PCATCH, "shmget", 0);
454 if (error)
455 return error;
456 return EAGAIN;
457 }
458 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
459 return EEXIST;
460 error = ipcperm(p, &shmseg->shm_perm, mode);
461 if (error)
462 return error;
463 if (uap->size && uap->size > shmseg->shm_segsz)
464 return EINVAL;
465 uap->sysmsg_result = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
466 return 0;
467 }
468
469 static int
470 shmget_allocate_segment(struct proc *p, struct shmget_args *uap, int mode)
471 {
472 int i, segnum, shmid, size;
473 struct ucred *cred = p->p_ucred;
474 struct shmid_ds *shmseg;
475 struct shm_handle *shm_handle;
476
477 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
478 return EINVAL;
479 if (shm_nused >= shminfo.shmmni) /* any shmids left? */
480 return ENOSPC;
481 size = round_page(uap->size);
482 if (shm_committed + btoc(size) > shminfo.shmall)
483 return ENOMEM;
484 if (shm_last_free < 0) {
485 shmrealloc(); /* maybe expand the shmsegs[] array */
486 for (i = 0; i < shmalloced; i++)
487 if (shmsegs[i].shm_perm.mode & SHMSEG_FREE)
488 break;
489 if (i == shmalloced)
490 return ENOSPC;
491 segnum = i;
492 } else {
493 segnum = shm_last_free;
494 shm_last_free = -1;
495 }
496 shmseg = &shmsegs[segnum];
497 /*
498 * In case we sleep in malloc(), mark the segment present but deleted
499 * so that noone else tries to create the same key.
500 */
501 shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED;
502 shmseg->shm_perm.key = uap->key;
503 shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff;
504 shm_handle = kmalloc(sizeof(struct shm_handle), M_SHM, M_WAITOK);
505 shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
506
507 /*
508 * We make sure that we have allocated a pager before we need
509 * to.
510 */
511 if (shm_use_phys) {
512 shm_handle->shm_object =
513 vm_pager_allocate(OBJT_PHYS, 0, size, VM_PROT_DEFAULT, 0);
514 } else {
515 shm_handle->shm_object =
516 vm_pager_allocate(OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0);
517 }
518 vm_object_clear_flag(shm_handle->shm_object, OBJ_ONEMAPPING);
519 vm_object_set_flag(shm_handle->shm_object, OBJ_NOSPLIT);
520
521 shmseg->shm_internal = shm_handle;
522 shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid;
523 shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid;
524 shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) |
525 (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
526 shmseg->shm_segsz = uap->size;
527 shmseg->shm_cpid = p->p_pid;
528 shmseg->shm_lpid = shmseg->shm_nattch = 0;
529 shmseg->shm_atime = shmseg->shm_dtime = 0;
530 shmseg->shm_ctime = time_second;
531 shm_committed += btoc(size);
532 shm_nused++;
533 if (shmseg->shm_perm.mode & SHMSEG_WANTED) {
534 /*
535 * Somebody else wanted this key while we were asleep. Wake
536 * them up now.
537 */
538 shmseg->shm_perm.mode &= ~SHMSEG_WANTED;
539 wakeup((caddr_t)shmseg);
540 }
541 uap->sysmsg_result = shmid;
542 return 0;
543 }
544
545 int
546 sys_shmget(struct shmget_args *uap)
547 {
548 struct proc *p = curproc;
549 int segnum, mode, error;
550
551 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
552 return (ENOSYS);
553
554 mode = uap->shmflg & ACCESSPERMS;
555 if (uap->key != IPC_PRIVATE) {
556 again:
557 segnum = shm_find_segment_by_key(uap->key);
558 if (segnum >= 0) {
559 error = shmget_existing(p, uap, mode, segnum);
560 if (error == EAGAIN)
561 goto again;
562 return error;
563 }
564 if ((uap->shmflg & IPC_CREAT) == 0)
565 return ENOENT;
566 }
567 return shmget_allocate_segment(p, uap, mode);
568 }
569
570 /*
571 * shmsys_args(int which, int a2, ...) (VARARGS)
572 */
573 int
574 sys_shmsys(struct shmsys_args *uap)
575 {
576 struct proc *p = curproc;
577 unsigned int which = (unsigned int)uap->which;
578 int error;
579
580 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL)
581 return (ENOSYS);
582
583 if (which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
584 return EINVAL;
585 bcopy(&uap->a2, &uap->which,
586 sizeof(struct shmsys_args) - offsetof(struct shmsys_args, a2));
587 error = ((*shmcalls[which])(uap));
588 return(error);
589 }
590
591 void
592 shmfork(struct proc *p1, struct proc *p2)
593 {
594 struct shmmap_state *shmmap_s;
595 size_t size;
596 int i;
597
598 size = shminfo.shmseg * sizeof(struct shmmap_state);
599 shmmap_s = kmalloc(size, M_SHM, M_WAITOK);
600 bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmmap_s, size);
601 p2->p_vmspace->vm_shm = (caddr_t)shmmap_s;
602 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
603 if (shmmap_s->shmid != -1)
604 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].shm_nattch++;
605 }
606
607 void
608 shmexit(struct vmspace *vm)
609 {
610 struct shmmap_state *base, *shm;
611 int i;
612
613 if ((base = (struct shmmap_state *)vm->vm_shm) != NULL) {
614 vm->vm_shm = NULL;
615 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) {
616 if (shm->shmid != -1)
617 shm_delete_mapping(vm, shm);
618 }
619 kfree(base, M_SHM);
620 }
621 }
622
623 static void
624 shmrealloc(void)
625 {
626 int i;
627 struct shmid_ds *newsegs;
628
629 if (shmalloced >= shminfo.shmmni)
630 return;
631
632 newsegs = kmalloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK);
633 if (newsegs == NULL)
634 return;
635 for (i = 0; i < shmalloced; i++)
636 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
637 for (; i < shminfo.shmmni; i++) {
638 shmsegs[i].shm_perm.mode = SHMSEG_FREE;
639 shmsegs[i].shm_perm.seq = 0;
640 }
641 kfree(shmsegs, M_SHM);
642 shmsegs = newsegs;
643 shmalloced = shminfo.shmmni;
644 }
645
646 static void
647 shminit(void *dummy)
648 {
649 int i;
650
651 shminfo.shmmax = shminfo.shmall * PAGE_SIZE;
652 shmalloced = shminfo.shmmni;
653 shmsegs = kmalloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK);
654 if (shmsegs == NULL)
655 panic("cannot allocate initial memory for sysvshm");
656 for (i = 0; i < shmalloced; i++) {
657 shmsegs[i].shm_perm.mode = SHMSEG_FREE;
658 shmsegs[i].shm_perm.seq = 0;
659 }
660 shm_last_free = 0;
661 shm_nused = 0;
662 shm_committed = 0;
663 }
664 SYSINIT(sysv_shm, SI_SUB_SYSV_SHM, SI_ORDER_FIRST, shminit, NULL);
DragonFly BSD