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_rlimit.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 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 1024 /* XXX increase this, it's not in kva! */ 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 96 113 #endif 114 #ifndef SHMSEG 115 #define SHMSEG 64 116 #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; 130 131 SYSCTL_DECL(_kern_ipc); 132 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0, ""); 133 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0, ""); 134 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RD, &shminfo.shmmni, 0, ""); 135 SYSCTL_INT(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RW, &shminfo.shmseg, 0, ""); 136 SYSCTL_INT(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0, ""); 137 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW, &shm_use_phys, 0, ""); 138 139 static int 140 shm_find_segment_by_key(key) 141 key_t key; 142 { 143 int i; 144 145 for (i = 0; i < shmalloced; i++) 146 if ((shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED) && 147 shmsegs[i].shm_perm.key == key) 148 return i; 149 return -1; 150 } 151 152 static struct shmid_ds * 153 shm_find_segment_by_shmid(shmid) 154 int shmid; 155 { 156 int segnum; 157 struct shmid_ds *shmseg; 158 159 segnum = IPCID_TO_IX(shmid); 160 if (segnum < 0 || segnum >= shmalloced) 161 return NULL; 162 shmseg = &shmsegs[segnum]; 163 if ((shmseg->shm_perm.mode & (SHMSEG_ALLOCATED | SHMSEG_REMOVED)) 164 != SHMSEG_ALLOCATED || 165 shmseg->shm_perm.seq != IPCID_TO_SEQ(shmid)) 166 return NULL; 167 return shmseg; 168 } 169 170 static void 171 shm_deallocate_segment(shmseg) 172 struct shmid_ds *shmseg; 173 { 174 struct shm_handle *shm_handle; 175 size_t size; 176 177 shm_handle = shmseg->shm_internal; 178 vm_object_deallocate(shm_handle->shm_object); 179 free((caddr_t)shm_handle, M_SHM); 180 shmseg->shm_internal = NULL; 181 size = round_page(shmseg->shm_segsz); 182 shm_committed -= btoc(size); 183 shm_nused--; 184 shmseg->shm_perm.mode = SHMSEG_FREE; 185 } 186 187 static int 188 shm_delete_mapping(p, shmmap_s) 189 struct proc *p; 190 struct shmmap_state *shmmap_s; 191 { 192 struct shmid_ds *shmseg; 193 int segnum, result; 194 size_t size; 195 196 segnum = IPCID_TO_IX(shmmap_s->shmid); 197 shmseg = &shmsegs[segnum]; 198 size = round_page(shmseg->shm_segsz); 199 result = vm_map_remove(&p->p_vmspace->vm_map, shmmap_s->va, shmmap_s->va + size); 200 if (result != KERN_SUCCESS) 201 return EINVAL; 202 shmmap_s->shmid = -1; 203 shmseg->shm_dtime = time_second; 204 if ((--shmseg->shm_nattch <= 0) && 205 (shmseg->shm_perm.mode & SHMSEG_REMOVED)) { 206 shm_deallocate_segment(shmseg); 207 shm_last_free = segnum; 208 } 209 return 0; 210 } 211 212 #ifndef _SYS_SYSPROTO_H_ 213 struct shmdt_args { 214 void *shmaddr; 215 }; 216 #endif 217 218 int 219 shmdt(p, uap) 220 struct proc *p; 221 struct shmdt_args *uap; 222 { 223 struct shmmap_state *shmmap_s; 224 int i; 225 226 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; 227 if (shmmap_s == NULL) 228 return EINVAL; 229 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) 230 if (shmmap_s->shmid != -1 && 231 shmmap_s->va == (vm_offset_t)uap->shmaddr) 232 break; 233 if (i == shminfo.shmseg) 234 return EINVAL; 235 return shm_delete_mapping(p, shmmap_s); 236 } 237 238 #ifndef _SYS_SYSPROTO_H_ 239 struct shmat_args { 240 int shmid; 241 void *shmaddr; 242 int shmflg; 243 }; 244 #endif 245 246 int 247 shmat(p, uap) 248 struct proc *p; 249 struct shmat_args *uap; 250 { 251 int error, i, flags; 252 struct shmid_ds *shmseg; 253 struct shmmap_state *shmmap_s = NULL; 254 struct shm_handle *shm_handle; 255 vm_offset_t attach_va; 256 vm_prot_t prot; 257 vm_size_t size; 258 int rv; 259 260 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; 261 if (shmmap_s == NULL) { 262 size = shminfo.shmseg * sizeof(struct shmmap_state); 263 shmmap_s = malloc(size, M_SHM, M_WAITOK); 264 for (i = 0; i < shminfo.shmseg; i++) 265 shmmap_s[i].shmid = -1; 266 p->p_vmspace->vm_shm = (caddr_t)shmmap_s; 267 } 268 shmseg = shm_find_segment_by_shmid(uap->shmid); 269 if (shmseg == NULL) 270 return EINVAL; 271 error = ipcperm(p, &shmseg->shm_perm, 272 (uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); 273 if (error) 274 return error; 275 for (i = 0; i < shminfo.shmseg; i++) { 276 if (shmmap_s->shmid == -1) 277 break; 278 shmmap_s++; 279 } 280 if (i >= shminfo.shmseg) 281 return EMFILE; 282 size = round_page(shmseg->shm_segsz); 283 #ifdef VM_PROT_READ_IS_EXEC 284 prot = VM_PROT_READ | VM_PROT_EXECUTE; 285 #else 286 prot = VM_PROT_READ; 287 #endif 288 if ((uap->shmflg & SHM_RDONLY) == 0) 289 prot |= VM_PROT_WRITE; 290 flags = MAP_ANON | MAP_SHARED; 291 if (uap->shmaddr) { 292 flags |= MAP_FIXED; 293 if (uap->shmflg & SHM_RND) 294 attach_va = (vm_offset_t)uap->shmaddr & ~(SHMLBA-1); 295 else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0) 296 attach_va = (vm_offset_t)uap->shmaddr; 297 else 298 return EINVAL; 299 } else { 300 /* This is just a hint to vm_map_find() about where to put it. */ 301 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_taddr + MAXTSIZ + MAXDSIZ); 302 } 303 304 shm_handle = shmseg->shm_internal; 305 vm_object_reference(shm_handle->shm_object); 306 rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object, 307 0, &attach_va, size, (flags & MAP_FIXED)?0:1, prot, prot, 0); 308 if (rv != KERN_SUCCESS) { 309 return ENOMEM; 310 } 311 vm_map_inherit(&p->p_vmspace->vm_map, 312 attach_va, attach_va + size, VM_INHERIT_SHARE); 313 314 shmmap_s->va = attach_va; 315 shmmap_s->shmid = uap->shmid; 316 shmseg->shm_lpid = p->p_pid; 317 shmseg->shm_atime = time_second; 318 shmseg->shm_nattch++; 319 p->p_retval[0] = attach_va; 320 return 0; 321 } 322 323 struct oshmid_ds { 324 struct ipc_perm shm_perm; /* operation perms */ 325 int shm_segsz; /* size of segment (bytes) */ 326 ushort shm_cpid; /* pid, creator */ 327 ushort shm_lpid; /* pid, last operation */ 328 short shm_nattch; /* no. of current attaches */ 329 time_t shm_atime; /* last attach time */ 330 time_t shm_dtime; /* last detach time */ 331 time_t shm_ctime; /* last change time */ 332 void *shm_handle; /* internal handle for shm segment */ 333 }; 334 335 struct oshmctl_args { 336 int shmid; 337 int cmd; 338 struct oshmid_ds *ubuf; 339 }; 340 341 static int 342 oshmctl(p, uap) 343 struct proc *p; 344 struct oshmctl_args *uap; 345 { 346 #ifdef COMPAT_43 347 int error; 348 struct shmid_ds *shmseg; 349 struct oshmid_ds outbuf; 350 351 shmseg = shm_find_segment_by_shmid(uap->shmid); 352 if (shmseg == NULL) 353 return EINVAL; 354 switch (uap->cmd) { 355 case IPC_STAT: 356 error = ipcperm(p, &shmseg->shm_perm, IPC_R); 357 if (error) 358 return error; 359 outbuf.shm_perm = shmseg->shm_perm; 360 outbuf.shm_segsz = shmseg->shm_segsz; 361 outbuf.shm_cpid = shmseg->shm_cpid; 362 outbuf.shm_lpid = shmseg->shm_lpid; 363 outbuf.shm_nattch = shmseg->shm_nattch; 364 outbuf.shm_atime = shmseg->shm_atime; 365 outbuf.shm_dtime = shmseg->shm_dtime; 366 outbuf.shm_ctime = shmseg->shm_ctime; 367 outbuf.shm_handle = shmseg->shm_internal; 368 error = copyout((caddr_t)&outbuf, uap->ubuf, sizeof(outbuf)); 369 if (error) 370 return error; 371 break; 372 default: 373 /* XXX casting to (sy_call_t *) is bogus, as usual. */ 374 return ((sy_call_t *)shmctl)(p, uap); 375 } 376 return 0; 377 #else 378 return EINVAL; 379 #endif 380 } 381 382 #ifndef _SYS_SYSPROTO_H_ 383 struct shmctl_args { 384 int shmid; 385 int cmd; 386 struct shmid_ds *buf; 387 }; 388 #endif 389 390 int 391 shmctl(p, uap) 392 struct proc *p; 393 struct shmctl_args *uap; 394 { 395 int error; 396 struct shmid_ds inbuf; 397 struct shmid_ds *shmseg; 398 399 shmseg = shm_find_segment_by_shmid(uap->shmid); 400 if (shmseg == NULL) 401 return EINVAL; 402 switch (uap->cmd) { 403 case IPC_STAT: 404 error = ipcperm(p, &shmseg->shm_perm, IPC_R); 405 if (error) 406 return error; 407 error = copyout((caddr_t)shmseg, uap->buf, sizeof(inbuf)); 408 if (error) 409 return error; 410 break; 411 case IPC_SET: 412 error = ipcperm(p, &shmseg->shm_perm, IPC_M); 413 if (error) 414 return error; 415 error = copyin(uap->buf, (caddr_t)&inbuf, sizeof(inbuf)); 416 if (error) 417 return error; 418 shmseg->shm_perm.uid = inbuf.shm_perm.uid; 419 shmseg->shm_perm.gid = inbuf.shm_perm.gid; 420 shmseg->shm_perm.mode = 421 (shmseg->shm_perm.mode & ~ACCESSPERMS) | 422 (inbuf.shm_perm.mode & ACCESSPERMS); 423 shmseg->shm_ctime = time_second; 424 break; 425 case IPC_RMID: 426 error = ipcperm(p, &shmseg->shm_perm, IPC_M); 427 if (error) 428 return error; 429 shmseg->shm_perm.key = IPC_PRIVATE; 430 shmseg->shm_perm.mode |= SHMSEG_REMOVED; 431 if (shmseg->shm_nattch <= 0) { 432 shm_deallocate_segment(shmseg); 433 shm_last_free = IPCID_TO_IX(uap->shmid); 434 } 435 break; 436 #if 0 437 case SHM_LOCK: 438 case SHM_UNLOCK: 439 #endif 440 default: 441 return EINVAL; 442 } 443 return 0; 444 } 445 446 #ifndef _SYS_SYSPROTO_H_ 447 struct shmget_args { 448 key_t key; 449 size_t size; 450 int shmflg; 451 }; 452 #endif 453 454 static int 455 shmget_existing(p, uap, mode, segnum) 456 struct proc *p; 457 struct shmget_args *uap; 458 int mode; 459 int segnum; 460 { 461 struct shmid_ds *shmseg; 462 int error; 463 464 shmseg = &shmsegs[segnum]; 465 if (shmseg->shm_perm.mode & SHMSEG_REMOVED) { 466 /* 467 * This segment is in the process of being allocated. Wait 468 * until it's done, and look the key up again (in case the 469 * allocation failed or it was freed). 470 */ 471 shmseg->shm_perm.mode |= SHMSEG_WANTED; 472 error = tsleep((caddr_t)shmseg, PLOCK | PCATCH, "shmget", 0); 473 if (error) 474 return error; 475 return EAGAIN; 476 } 477 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) 478 return EEXIST; 479 error = ipcperm(p, &shmseg->shm_perm, mode); 480 if (error) 481 return error; 482 if (uap->size && uap->size > shmseg->shm_segsz) 483 return EINVAL; 484 p->p_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm); 485 return 0; 486 } 487 488 static int 489 shmget_allocate_segment(p, uap, mode) 490 struct proc *p; 491 struct shmget_args *uap; 492 int mode; 493 { 494 int i, segnum, shmid, size; 495 struct ucred *cred = p->p_ucred; 496 struct shmid_ds *shmseg; 497 struct shm_handle *shm_handle; 498 499 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) 500 return EINVAL; 501 if (shm_nused >= shminfo.shmmni) /* any shmids left? */ 502 return ENOSPC; 503 size = round_page(uap->size); 504 if (shm_committed + btoc(size) > shminfo.shmall) 505 return ENOMEM; 506 if (shm_last_free < 0) { 507 shmrealloc(); /* maybe expand the shmsegs[] array */ 508 for (i = 0; i < shmalloced; i++) 509 if (shmsegs[i].shm_perm.mode & SHMSEG_FREE) 510 break; 511 if (i == shmalloced) 512 return ENOSPC; 513 segnum = i; 514 } else { 515 segnum = shm_last_free; 516 shm_last_free = -1; 517 } 518 shmseg = &shmsegs[segnum]; 519 /* 520 * In case we sleep in malloc(), mark the segment present but deleted 521 * so that noone else tries to create the same key. 522 */ 523 shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED; 524 shmseg->shm_perm.key = uap->key; 525 shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff; 526 shm_handle = (struct shm_handle *) 527 malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK); 528 shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm); 529 530 /* 531 * We make sure that we have allocated a pager before we need 532 * to. 533 */ 534 if (shm_use_phys) { 535 shm_handle->shm_object = 536 vm_pager_allocate(OBJT_PHYS, 0, size, VM_PROT_DEFAULT, 0); 537 } else { 538 shm_handle->shm_object = 539 vm_pager_allocate(OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0); 540 } 541 vm_object_clear_flag(shm_handle->shm_object, OBJ_ONEMAPPING); 542 vm_object_set_flag(shm_handle->shm_object, OBJ_NOSPLIT); 543 544 shmseg->shm_internal = shm_handle; 545 shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid; 546 shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid; 547 shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) | 548 (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; 549 shmseg->shm_segsz = uap->size; 550 shmseg->shm_cpid = p->p_pid; 551 shmseg->shm_lpid = shmseg->shm_nattch = 0; 552 shmseg->shm_atime = shmseg->shm_dtime = 0; 553 shmseg->shm_ctime = time_second; 554 shm_committed += btoc(size); 555 shm_nused++; 556 if (shmseg->shm_perm.mode & SHMSEG_WANTED) { 557 /* 558 * Somebody else wanted this key while we were asleep. Wake 559 * them up now. 560 */ 561 shmseg->shm_perm.mode &= ~SHMSEG_WANTED; 562 wakeup((caddr_t)shmseg); 563 } 564 p->p_retval[0] = shmid; 565 return 0; 566 } 567 568 int 569 shmget(p, uap) 570 struct proc *p; 571 struct shmget_args *uap; 572 { 573 int segnum, mode, error; 574 575 mode = uap->shmflg & ACCESSPERMS; 576 if (uap->key != IPC_PRIVATE) { 577 again: 578 segnum = shm_find_segment_by_key(uap->key); 579 if (segnum >= 0) { 580 error = shmget_existing(p, uap, mode, segnum); 581 if (error == EAGAIN) 582 goto again; 583 return error; 584 } 585 if ((uap->shmflg & IPC_CREAT) == 0) 586 return ENOENT; 587 } 588 return shmget_allocate_segment(p, uap, mode); 589 } 590 591 int 592 shmsys(p, uap) 593 struct proc *p; 594 /* XXX actually varargs. */ 595 struct shmsys_args /* { 596 u_int which; 597 int a2; 598 int a3; 599 int a4; 600 } */ *uap; 601 { 602 603 if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0])) 604 return EINVAL; 605 return ((*shmcalls[uap->which])(p, &uap->a2)); 606 } 607 608 void 609 shmfork(p1, p2) 610 struct proc *p1, *p2; 611 { 612 struct shmmap_state *shmmap_s; 613 size_t size; 614 int i; 615 616 size = shminfo.shmseg * sizeof(struct shmmap_state); 617 shmmap_s = malloc(size, M_SHM, M_WAITOK); 618 bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmmap_s, size); 619 p2->p_vmspace->vm_shm = (caddr_t)shmmap_s; 620 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) 621 if (shmmap_s->shmid != -1) 622 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].shm_nattch++; 623 } 624 625 void 626 shmexit(p) 627 struct proc *p; 628 { 629 struct shmmap_state *shmmap_s; 630 int i; 631 632 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; 633 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) 634 if (shmmap_s->shmid != -1) 635 shm_delete_mapping(p, shmmap_s); 636 free((caddr_t)p->p_vmspace->vm_shm, M_SHM); 637 p->p_vmspace->vm_shm = NULL; 638 } 639 640 static void 641 shmrealloc(void) 642 { 643 int i; 644 struct shmid_ds *newsegs; 645 646 if (shmalloced >= shminfo.shmmni) 647 return; 648 649 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK); 650 if (newsegs == NULL) 651 return; 652 for (i = 0; i < shmalloced; i++) 653 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 654 for (; i < shminfo.shmmni; i++) { 655 shmsegs[i].shm_perm.mode = SHMSEG_FREE; 656 shmsegs[i].shm_perm.seq = 0; 657 } 658 free(shmsegs, M_SHM); 659 shmsegs = newsegs; 660 shmalloced = shminfo.shmmni; 661 } 662 663 static void 664 shminit(dummy) 665 void *dummy; 666 { 667 int i; 668 669 shmalloced = shminfo.shmmni; 670 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK); 671 if (shmsegs == NULL) 672 panic("cannot allocate initial memory for sysvshm"); 673 for (i = 0; i < shmalloced; i++) { 674 shmsegs[i].shm_perm.mode = SHMSEG_FREE; 675 shmsegs[i].shm_perm.seq = 0; 676 } 677 shm_last_free = 0; 678 shm_nused = 0; 679 shm_committed = 0; 680 } 681 SYSINIT(sysv_shm, SI_SUB_SYSV_SHM, SI_ORDER_FIRST, shminit, NULL); 682