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 1.17 2006/06/05 07:26:10 dillon 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) 147 key_t key; 148 { 149 int i; 150 151 for (i = 0; i < shmalloced; i++) 152 if ((shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED) && 153 shmsegs[i].shm_perm.key == key) 154 return i; 155 return -1; 156 } 157 158 static struct shmid_ds * 159 shm_find_segment_by_shmid(shmid) 160 int shmid; 161 { 162 int segnum; 163 struct shmid_ds *shmseg; 164 165 segnum = IPCID_TO_IX(shmid); 166 if (segnum < 0 || segnum >= shmalloced) 167 return NULL; 168 shmseg = &shmsegs[segnum]; 169 if ((shmseg->shm_perm.mode & (SHMSEG_ALLOCATED | SHMSEG_REMOVED)) 170 != SHMSEG_ALLOCATED || 171 shmseg->shm_perm.seq != IPCID_TO_SEQ(shmid)) 172 return NULL; 173 return shmseg; 174 } 175 176 static void 177 shm_deallocate_segment(shmseg) 178 struct shmid_ds *shmseg; 179 { 180 struct shm_handle *shm_handle; 181 size_t size; 182 183 shm_handle = shmseg->shm_internal; 184 vm_object_deallocate(shm_handle->shm_object); 185 free((caddr_t)shm_handle, M_SHM); 186 shmseg->shm_internal = NULL; 187 size = round_page(shmseg->shm_segsz); 188 shm_committed -= btoc(size); 189 shm_nused--; 190 shmseg->shm_perm.mode = SHMSEG_FREE; 191 } 192 193 static int 194 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s) 195 { 196 struct shmid_ds *shmseg; 197 int segnum, result; 198 size_t size; 199 200 segnum = IPCID_TO_IX(shmmap_s->shmid); 201 shmseg = &shmsegs[segnum]; 202 size = round_page(shmseg->shm_segsz); 203 result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size); 204 if (result != KERN_SUCCESS) 205 return EINVAL; 206 shmmap_s->shmid = -1; 207 shmseg->shm_dtime = time_second; 208 if ((--shmseg->shm_nattch <= 0) && 209 (shmseg->shm_perm.mode & SHMSEG_REMOVED)) { 210 shm_deallocate_segment(shmseg); 211 shm_last_free = segnum; 212 } 213 return 0; 214 } 215 216 int 217 sys_shmdt(struct shmdt_args *uap) 218 { 219 struct proc *p = curproc; 220 struct shmmap_state *shmmap_s; 221 int i; 222 223 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL) 224 return (ENOSYS); 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->p_vmspace, shmmap_s); 236 } 237 238 int 239 sys_shmat(struct shmat_args *uap) 240 { 241 struct proc *p = curproc; 242 int error, i, flags; 243 struct shmid_ds *shmseg; 244 struct shmmap_state *shmmap_s = NULL; 245 struct shm_handle *shm_handle; 246 vm_offset_t attach_va; 247 vm_prot_t prot; 248 vm_size_t size; 249 int rv; 250 251 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL) 252 return (ENOSYS); 253 254 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; 255 if (shmmap_s == NULL) { 256 size = shminfo.shmseg * sizeof(struct shmmap_state); 257 shmmap_s = malloc(size, M_SHM, M_WAITOK); 258 for (i = 0; i < shminfo.shmseg; i++) 259 shmmap_s[i].shmid = -1; 260 p->p_vmspace->vm_shm = (caddr_t)shmmap_s; 261 } 262 shmseg = shm_find_segment_by_shmid(uap->shmid); 263 if (shmseg == NULL) 264 return EINVAL; 265 error = ipcperm(p, &shmseg->shm_perm, 266 (uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); 267 if (error) 268 return error; 269 for (i = 0; i < shminfo.shmseg; i++) { 270 if (shmmap_s->shmid == -1) 271 break; 272 shmmap_s++; 273 } 274 if (i >= shminfo.shmseg) 275 return EMFILE; 276 size = round_page(shmseg->shm_segsz); 277 #ifdef VM_PROT_READ_IS_EXEC 278 prot = VM_PROT_READ | VM_PROT_EXECUTE; 279 #else 280 prot = VM_PROT_READ; 281 #endif 282 if ((uap->shmflg & SHM_RDONLY) == 0) 283 prot |= VM_PROT_WRITE; 284 flags = MAP_ANON | MAP_SHARED; 285 if (uap->shmaddr) { 286 flags |= MAP_FIXED; 287 if (uap->shmflg & SHM_RND) 288 attach_va = (vm_offset_t)uap->shmaddr & ~(SHMLBA-1); 289 else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0) 290 attach_va = (vm_offset_t)uap->shmaddr; 291 else 292 return EINVAL; 293 } else { 294 /* This is just a hint to vm_map_find() about where to put it. */ 295 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_taddr + maxtsiz + maxdsiz); 296 } 297 298 shm_handle = shmseg->shm_internal; 299 vm_object_reference(shm_handle->shm_object); 300 rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object, 301 0, &attach_va, size, (flags & MAP_FIXED)?0:1, prot, prot, 0); 302 if (rv != KERN_SUCCESS) { 303 vm_object_deallocate(shm_handle->shm_object); 304 return ENOMEM; 305 } 306 vm_map_inherit(&p->p_vmspace->vm_map, 307 attach_va, attach_va + size, VM_INHERIT_SHARE); 308 309 shmmap_s->va = attach_va; 310 shmmap_s->shmid = uap->shmid; 311 shmseg->shm_lpid = p->p_pid; 312 shmseg->shm_atime = time_second; 313 shmseg->shm_nattch++; 314 uap->sysmsg_result = attach_va; 315 return 0; 316 } 317 318 struct oshmid_ds { 319 struct ipc_perm shm_perm; /* operation perms */ 320 int shm_segsz; /* size of segment (bytes) */ 321 ushort shm_cpid; /* pid, creator */ 322 ushort shm_lpid; /* pid, last operation */ 323 short shm_nattch; /* no. of current attaches */ 324 time_t shm_atime; /* last attach time */ 325 time_t shm_dtime; /* last detach time */ 326 time_t shm_ctime; /* last change time */ 327 void *shm_handle; /* internal handle for shm segment */ 328 }; 329 330 struct oshmctl_args { 331 struct sysmsg sysmsg; 332 int shmid; 333 int cmd; 334 struct oshmid_ds *ubuf; 335 }; 336 337 static int 338 sys_oshmctl(p, uap) 339 struct proc *p; 340 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(p, uap, mode, segnum) 441 struct proc *p; 442 struct shmget_args *uap; 443 int mode; 444 int segnum; 445 { 446 struct shmid_ds *shmseg; 447 int error; 448 449 shmseg = &shmsegs[segnum]; 450 if (shmseg->shm_perm.mode & SHMSEG_REMOVED) { 451 /* 452 * This segment is in the process of being allocated. Wait 453 * until it's done, and look the key up again (in case the 454 * allocation failed or it was freed). 455 */ 456 shmseg->shm_perm.mode |= SHMSEG_WANTED; 457 error = tsleep((caddr_t)shmseg, PCATCH, "shmget", 0); 458 if (error) 459 return error; 460 return EAGAIN; 461 } 462 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) 463 return EEXIST; 464 error = ipcperm(p, &shmseg->shm_perm, mode); 465 if (error) 466 return error; 467 if (uap->size && uap->size > shmseg->shm_segsz) 468 return EINVAL; 469 uap->sysmsg_result = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm); 470 return 0; 471 } 472 473 static int 474 shmget_allocate_segment(p, uap, mode) 475 struct proc *p; 476 struct shmget_args *uap; 477 int mode; 478 { 479 int i, segnum, shmid, size; 480 struct ucred *cred = p->p_ucred; 481 struct shmid_ds *shmseg; 482 struct shm_handle *shm_handle; 483 484 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) 485 return EINVAL; 486 if (shm_nused >= shminfo.shmmni) /* any shmids left? */ 487 return ENOSPC; 488 size = round_page(uap->size); 489 if (shm_committed + btoc(size) > shminfo.shmall) 490 return ENOMEM; 491 if (shm_last_free < 0) { 492 shmrealloc(); /* maybe expand the shmsegs[] array */ 493 for (i = 0; i < shmalloced; i++) 494 if (shmsegs[i].shm_perm.mode & SHMSEG_FREE) 495 break; 496 if (i == shmalloced) 497 return ENOSPC; 498 segnum = i; 499 } else { 500 segnum = shm_last_free; 501 shm_last_free = -1; 502 } 503 shmseg = &shmsegs[segnum]; 504 /* 505 * In case we sleep in malloc(), mark the segment present but deleted 506 * so that noone else tries to create the same key. 507 */ 508 shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED; 509 shmseg->shm_perm.key = uap->key; 510 shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff; 511 shm_handle = malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK); 512 shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm); 513 514 /* 515 * We make sure that we have allocated a pager before we need 516 * to. 517 */ 518 if (shm_use_phys) { 519 shm_handle->shm_object = 520 vm_pager_allocate(OBJT_PHYS, 0, size, VM_PROT_DEFAULT, 0); 521 } else { 522 shm_handle->shm_object = 523 vm_pager_allocate(OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0); 524 } 525 vm_object_clear_flag(shm_handle->shm_object, OBJ_ONEMAPPING); 526 vm_object_set_flag(shm_handle->shm_object, OBJ_NOSPLIT); 527 528 shmseg->shm_internal = shm_handle; 529 shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid; 530 shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid; 531 shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) | 532 (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; 533 shmseg->shm_segsz = uap->size; 534 shmseg->shm_cpid = p->p_pid; 535 shmseg->shm_lpid = shmseg->shm_nattch = 0; 536 shmseg->shm_atime = shmseg->shm_dtime = 0; 537 shmseg->shm_ctime = time_second; 538 shm_committed += btoc(size); 539 shm_nused++; 540 if (shmseg->shm_perm.mode & SHMSEG_WANTED) { 541 /* 542 * Somebody else wanted this key while we were asleep. Wake 543 * them up now. 544 */ 545 shmseg->shm_perm.mode &= ~SHMSEG_WANTED; 546 wakeup((caddr_t)shmseg); 547 } 548 uap->sysmsg_result = shmid; 549 return 0; 550 } 551 552 int 553 sys_shmget(struct shmget_args *uap) 554 { 555 struct proc *p = curproc; 556 int segnum, mode, error; 557 558 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL) 559 return (ENOSYS); 560 561 mode = uap->shmflg & ACCESSPERMS; 562 if (uap->key != IPC_PRIVATE) { 563 again: 564 segnum = shm_find_segment_by_key(uap->key); 565 if (segnum >= 0) { 566 error = shmget_existing(p, uap, mode, segnum); 567 if (error == EAGAIN) 568 goto again; 569 return error; 570 } 571 if ((uap->shmflg & IPC_CREAT) == 0) 572 return ENOENT; 573 } 574 return shmget_allocate_segment(p, uap, mode); 575 } 576 577 /* 578 * shmsys_args(int which, int a2, ...) (VARARGS) 579 */ 580 int 581 sys_shmsys(struct shmsys_args *uap) 582 { 583 struct proc *p = curproc; 584 unsigned int which = (unsigned int)uap->which; 585 int error; 586 587 if (!jail_sysvipc_allowed && p->p_ucred->cr_prison != NULL) 588 return (ENOSYS); 589 590 if (which >= sizeof(shmcalls)/sizeof(shmcalls[0])) 591 return EINVAL; 592 bcopy(&uap->a2, &uap->which, 593 sizeof(struct shmsys_args) - offsetof(struct shmsys_args, a2)); 594 error = ((*shmcalls[which])(uap)); 595 return(error); 596 } 597 598 void 599 shmfork(p1, p2) 600 struct proc *p1, *p2; 601 { 602 struct shmmap_state *shmmap_s; 603 size_t size; 604 int i; 605 606 size = shminfo.shmseg * sizeof(struct shmmap_state); 607 shmmap_s = malloc(size, M_SHM, M_WAITOK); 608 bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmmap_s, size); 609 p2->p_vmspace->vm_shm = (caddr_t)shmmap_s; 610 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) 611 if (shmmap_s->shmid != -1) 612 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].shm_nattch++; 613 } 614 615 void 616 shmexit(struct vmspace *vm) 617 { 618 struct shmmap_state *base, *shm; 619 int i; 620 621 if ((base = (struct shmmap_state *)vm->vm_shm) != NULL) { 622 vm->vm_shm = NULL; 623 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) { 624 if (shm->shmid != -1) 625 shm_delete_mapping(vm, shm); 626 } 627 free(base, M_SHM); 628 } 629 } 630 631 static void 632 shmrealloc(void) 633 { 634 int i; 635 struct shmid_ds *newsegs; 636 637 if (shmalloced >= shminfo.shmmni) 638 return; 639 640 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK); 641 if (newsegs == NULL) 642 return; 643 for (i = 0; i < shmalloced; i++) 644 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 645 for (; i < shminfo.shmmni; i++) { 646 shmsegs[i].shm_perm.mode = SHMSEG_FREE; 647 shmsegs[i].shm_perm.seq = 0; 648 } 649 free(shmsegs, M_SHM); 650 shmsegs = newsegs; 651 shmalloced = shminfo.shmmni; 652 } 653 654 static void 655 shminit(dummy) 656 void *dummy; 657 { 658 int i; 659 660 shminfo.shmmax = shminfo.shmall * PAGE_SIZE; 661 shmalloced = shminfo.shmmni; 662 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK); 663 if (shmsegs == NULL) 664 panic("cannot allocate initial memory for sysvshm"); 665 for (i = 0; i < shmalloced; i++) { 666 shmsegs[i].shm_perm.mode = SHMSEG_FREE; 667 shmsegs[i].shm_perm.seq = 0; 668 } 669 shm_last_free = 0; 670 shm_nused = 0; 671 shm_committed = 0; 672 } 673 SYSINIT(sysv_shm, SI_SUB_SYSV_SHM, SI_ORDER_FIRST, shminit, NULL); 674