sysv_shm.c revision 79224
1/* $FreeBSD: head/sys/kern/sysv_shm.c 79224 2001-07-04 16:20:28Z 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 236int 237shmdt(p, uap) 238 struct proc *p; 239 struct shmdt_args *uap; 240{ 241 struct shmmap_state *shmmap_s; 242 int i; 243 int error; 244 245 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) 246 return (ENOSYS); 247 248 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++) 252 if (shmmap_s->shmid != -1 && 253 shmmap_s->va == (vm_offset_t)uap->shmaddr) 254 break; 255 if (i == shminfo.shmseg) 256 return EINVAL; 257 error = shm_delete_mapping(p, shmmap_s); 258 return error; 259} 260 261#ifndef _SYS_SYSPROTO_H_ 262struct shmat_args { 263 int shmid; 264 void *shmaddr; 265 int shmflg; 266}; 267#endif 268 269int 270shmat(p, uap) 271 struct proc *p; 272 struct shmat_args *uap; 273{ 274 int error, i, flags; 275 struct shmid_ds *shmseg; 276 struct shmmap_state *shmmap_s = NULL; 277 struct shm_handle *shm_handle; 278 vm_offset_t attach_va; 279 vm_prot_t prot; 280 vm_size_t size; 281 int rv; 282 283 GIANT_REQUIRED; 284 285 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) 286 return (ENOSYS); 287 288 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; 289 if (shmmap_s == NULL) { 290 size = shminfo.shmseg * sizeof(struct shmmap_state); 291 shmmap_s = malloc(size, M_SHM, M_WAITOK); 292 for (i = 0; i < shminfo.shmseg; i++) 293 shmmap_s[i].shmid = -1; 294 p->p_vmspace->vm_shm = (caddr_t)shmmap_s; 295 } 296 shmseg = shm_find_segment_by_shmid(uap->shmid); 297 if (shmseg == NULL) 298 return EINVAL; 299 error = ipcperm(p, &shmseg->shm_perm, 300 (uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); 301 if (error) 302 return error; 303 for (i = 0; i < shminfo.shmseg; i++) { 304 if (shmmap_s->shmid == -1) 305 break; 306 shmmap_s++; 307 } 308 if (i >= shminfo.shmseg) 309 return EMFILE; 310 size = round_page(shmseg->shm_segsz); 311#ifdef VM_PROT_READ_IS_EXEC 312 prot = VM_PROT_READ | VM_PROT_EXECUTE; 313#else 314 prot = VM_PROT_READ; 315#endif 316 if ((uap->shmflg & SHM_RDONLY) == 0) 317 prot |= VM_PROT_WRITE; 318 flags = MAP_ANON | MAP_SHARED; 319 if (uap->shmaddr) { 320 flags |= MAP_FIXED; 321 if (uap->shmflg & SHM_RND) 322 attach_va = (vm_offset_t)uap->shmaddr & ~(SHMLBA-1); 323 else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0) 324 attach_va = (vm_offset_t)uap->shmaddr; 325 else 326 return EINVAL; 327 } else { 328 /* 329 * This is just a hint to vm_map_find() about where to 330 * put it. 331 */ 332 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_taddr 333 + MAXTSIZ + MAXDSIZ); 334 } 335 336 shm_handle = shmseg->shm_internal; 337 vm_object_reference(shm_handle->shm_object); 338 rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object, 339 0, &attach_va, size, (flags & MAP_FIXED)?0:1, prot, prot, 0); 340 if (rv != KERN_SUCCESS) { 341 return ENOMEM; 342 } 343 vm_map_inherit(&p->p_vmspace->vm_map, 344 attach_va, attach_va + size, VM_INHERIT_SHARE); 345 346 shmmap_s->va = attach_va; 347 shmmap_s->shmid = uap->shmid; 348 shmseg->shm_lpid = p->p_pid; 349 shmseg->shm_atime = time_second; 350 shmseg->shm_nattch++; 351 p->p_retval[0] = attach_va; 352 return 0; 353} 354 355struct oshmid_ds { 356 struct ipc_perm shm_perm; /* operation perms */ 357 int shm_segsz; /* size of segment (bytes) */ 358 ushort shm_cpid; /* pid, creator */ 359 ushort shm_lpid; /* pid, last operation */ 360 short shm_nattch; /* no. of current attaches */ 361 time_t shm_atime; /* last attach time */ 362 time_t shm_dtime; /* last detach time */ 363 time_t shm_ctime; /* last change time */ 364 void *shm_handle; /* internal handle for shm segment */ 365}; 366 367struct oshmctl_args { 368 int shmid; 369 int cmd; 370 struct oshmid_ds *ubuf; 371}; 372 373static int 374oshmctl(p, uap) 375 struct proc *p; 376 struct oshmctl_args *uap; 377{ 378#ifdef COMPAT_43 379 int error; 380 struct shmid_ds *shmseg; 381 struct oshmid_ds outbuf; 382 383 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) 384 return (ENOSYS); 385 386 shmseg = shm_find_segment_by_shmid(uap->shmid); 387 if (shmseg == NULL) 388 return EINVAL; 389 switch (uap->cmd) { 390 case IPC_STAT: 391 error = ipcperm(p, &shmseg->shm_perm, IPC_R); 392 if (error) 393 return error; 394 outbuf.shm_perm = shmseg->shm_perm; 395 outbuf.shm_segsz = shmseg->shm_segsz; 396 outbuf.shm_cpid = shmseg->shm_cpid; 397 outbuf.shm_lpid = shmseg->shm_lpid; 398 outbuf.shm_nattch = shmseg->shm_nattch; 399 outbuf.shm_atime = shmseg->shm_atime; 400 outbuf.shm_dtime = shmseg->shm_dtime; 401 outbuf.shm_ctime = shmseg->shm_ctime; 402 outbuf.shm_handle = shmseg->shm_internal; 403 error = copyout((caddr_t)&outbuf, uap->ubuf, sizeof(outbuf)); 404 if (error) 405 return error; 406 break; 407 default: 408 /* XXX casting to (sy_call_t *) is bogus, as usual. */ 409 return ((sy_call_t *)shmctl)(p, uap); 410 } 411 return 0; 412#else 413 return EINVAL; 414#endif 415} 416 417#ifndef _SYS_SYSPROTO_H_ 418struct shmctl_args { 419 int shmid; 420 int cmd; 421 struct shmid_ds *buf; 422}; 423#endif 424 425int 426shmctl(p, uap) 427 struct proc *p; 428 struct shmctl_args *uap; 429{ 430 int error; 431 struct shmid_ds inbuf; 432 struct shmid_ds *shmseg; 433 434 GIANT_REQUIRED; 435 436 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) 437 return (ENOSYS); 438 439 shmseg = shm_find_segment_by_shmid(uap->shmid); 440 if (shmseg == NULL) 441 return EINVAL; 442 switch (uap->cmd) { 443 case IPC_STAT: 444 error = ipcperm(p, &shmseg->shm_perm, IPC_R); 445 if (error) 446 return error; 447 error = copyout((caddr_t)shmseg, uap->buf, sizeof(inbuf)); 448 if (error) 449 return error; 450 break; 451 case IPC_SET: 452 error = ipcperm(p, &shmseg->shm_perm, IPC_M); 453 if (error) 454 return error; 455 error = copyin(uap->buf, (caddr_t)&inbuf, sizeof(inbuf)); 456 if (error) 457 return error; 458 shmseg->shm_perm.uid = inbuf.shm_perm.uid; 459 shmseg->shm_perm.gid = inbuf.shm_perm.gid; 460 shmseg->shm_perm.mode = 461 (shmseg->shm_perm.mode & ~ACCESSPERMS) | 462 (inbuf.shm_perm.mode & ACCESSPERMS); 463 shmseg->shm_ctime = time_second; 464 break; 465 case IPC_RMID: 466 error = ipcperm(p, &shmseg->shm_perm, IPC_M); 467 if (error) 468 return error; 469 shmseg->shm_perm.key = IPC_PRIVATE; 470 shmseg->shm_perm.mode |= SHMSEG_REMOVED; 471 if (shmseg->shm_nattch <= 0) { 472 shm_deallocate_segment(shmseg); 473 shm_last_free = IPCID_TO_IX(uap->shmid); 474 } 475 break; 476#if 0 477 case SHM_LOCK: 478 case SHM_UNLOCK: 479#endif 480 default: 481 return EINVAL; 482 } 483 return 0; 484} 485 486#ifndef _SYS_SYSPROTO_H_ 487struct shmget_args { 488 key_t key; 489 size_t size; 490 int shmflg; 491}; 492#endif 493 494static int 495shmget_existing(p, uap, mode, segnum) 496 struct proc *p; 497 struct shmget_args *uap; 498 int mode; 499 int segnum; 500{ 501 struct shmid_ds *shmseg; 502 int error; 503 504 shmseg = &shmsegs[segnum]; 505 if (shmseg->shm_perm.mode & SHMSEG_REMOVED) { 506 /* 507 * This segment is in the process of being allocated. Wait 508 * until it's done, and look the key up again (in case the 509 * allocation failed or it was freed). 510 */ 511 shmseg->shm_perm.mode |= SHMSEG_WANTED; 512 error = tsleep((caddr_t)shmseg, PLOCK | PCATCH, "shmget", 0); 513 if (error) 514 return error; 515 return EAGAIN; 516 } 517 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) 518 return EEXIST; 519 error = ipcperm(p, &shmseg->shm_perm, mode); 520 if (error) 521 return error; 522 if (uap->size && uap->size > shmseg->shm_segsz) 523 return EINVAL; 524 p->p_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm); 525 return 0; 526} 527 528static int 529shmget_allocate_segment(p, uap, mode) 530 struct proc *p; 531 struct shmget_args *uap; 532 int mode; 533{ 534 int i, segnum, shmid, size; 535 struct ucred *cred = p->p_ucred; 536 struct shmid_ds *shmseg; 537 struct shm_handle *shm_handle; 538 539 GIANT_REQUIRED; 540 541 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) 542 return EINVAL; 543 if (shm_nused >= shminfo.shmmni) /* Any shmids left? */ 544 return ENOSPC; 545 size = round_page(uap->size); 546 if (shm_committed + btoc(size) > shminfo.shmall) 547 return ENOMEM; 548 if (shm_last_free < 0) { 549 shmrealloc(); /* Maybe expand the shmsegs[] array. */ 550 for (i = 0; i < shmalloced; i++) 551 if (shmsegs[i].shm_perm.mode & SHMSEG_FREE) 552 break; 553 if (i == shmalloced) 554 return ENOSPC; 555 segnum = i; 556 } else { 557 segnum = shm_last_free; 558 shm_last_free = -1; 559 } 560 shmseg = &shmsegs[segnum]; 561 /* 562 * In case we sleep in malloc(), mark the segment present but deleted 563 * so that noone else tries to create the same key. 564 */ 565 shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED; 566 shmseg->shm_perm.key = uap->key; 567 shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff; 568 shm_handle = (struct shm_handle *) 569 malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK); 570 shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm); 571 572 /* 573 * We make sure that we have allocated a pager before we need 574 * to. 575 */ 576 if (shm_use_phys) { 577 shm_handle->shm_object = 578 vm_pager_allocate(OBJT_PHYS, 0, size, VM_PROT_DEFAULT, 0); 579 } else { 580 shm_handle->shm_object = 581 vm_pager_allocate(OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0); 582 } 583 vm_object_clear_flag(shm_handle->shm_object, OBJ_ONEMAPPING); 584 vm_object_set_flag(shm_handle->shm_object, OBJ_NOSPLIT); 585 586 shmseg->shm_internal = shm_handle; 587 shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid; 588 shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid; 589 shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) | 590 (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; 591 shmseg->shm_segsz = uap->size; 592 shmseg->shm_cpid = p->p_pid; 593 shmseg->shm_lpid = shmseg->shm_nattch = 0; 594 shmseg->shm_atime = shmseg->shm_dtime = 0; 595 shmseg->shm_ctime = time_second; 596 shm_committed += btoc(size); 597 shm_nused++; 598 if (shmseg->shm_perm.mode & SHMSEG_WANTED) { 599 /* 600 * Somebody else wanted this key while we were asleep. Wake 601 * them up now. 602 */ 603 shmseg->shm_perm.mode &= ~SHMSEG_WANTED; 604 wakeup((caddr_t)shmseg); 605 } 606 p->p_retval[0] = shmid; 607 return 0; 608} 609 610int 611shmget(p, uap) 612 struct proc *p; 613 struct shmget_args *uap; 614{ 615 int segnum, mode, error; 616 617 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) 618 return (ENOSYS); 619 620 mode = uap->shmflg & ACCESSPERMS; 621 if (uap->key != IPC_PRIVATE) { 622 again: 623 segnum = shm_find_segment_by_key(uap->key); 624 if (segnum >= 0) { 625 error = shmget_existing(p, uap, mode, segnum); 626 if (error == EAGAIN) 627 goto again; 628 return error; 629 } 630 if ((uap->shmflg & IPC_CREAT) == 0) 631 return ENOENT; 632 } 633 return shmget_allocate_segment(p, uap, mode); 634} 635 636int 637shmsys(p, uap) 638 struct proc *p; 639 /* XXX actually varargs. */ 640 struct shmsys_args /* { 641 u_int which; 642 int a2; 643 int a3; 644 int a4; 645 } */ *uap; 646{ 647 648 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) 649 return (ENOSYS); 650 651 if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0])) 652 return EINVAL; 653 return ((*shmcalls[uap->which])(p, &uap->a2)); 654} 655 656static void 657shmfork_myhook(p1, p2) 658 struct proc *p1, *p2; 659{ 660 struct shmmap_state *shmmap_s; 661 size_t size; 662 int i; 663 664 size = shminfo.shmseg * sizeof(struct shmmap_state); 665 shmmap_s = malloc(size, M_SHM, M_WAITOK); 666 bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmmap_s, size); 667 p2->p_vmspace->vm_shm = (caddr_t)shmmap_s; 668 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) 669 if (shmmap_s->shmid != -1) 670 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].shm_nattch++; 671} 672 673static void 674shmexit_myhook(p) 675 struct proc *p; 676{ 677 struct shmmap_state *shmmap_s; 678 int i; 679 680 GIANT_REQUIRED; 681 682 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; 683 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) 684 if (shmmap_s->shmid != -1) 685 shm_delete_mapping(p, shmmap_s); 686 free((caddr_t)p->p_vmspace->vm_shm, M_SHM); 687 p->p_vmspace->vm_shm = NULL; 688} 689 690static void 691shmrealloc(void) 692{ 693 int i; 694 struct shmid_ds *newsegs; 695 696 if (shmalloced >= shminfo.shmmni) 697 return; 698 699 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK); 700 if (newsegs == NULL) 701 return; 702 for (i = 0; i < shmalloced; i++) 703 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 704 for (; i < shminfo.shmmni; i++) { 705 shmsegs[i].shm_perm.mode = SHMSEG_FREE; 706 shmsegs[i].shm_perm.seq = 0; 707 } 708 free(shmsegs, M_SHM); 709 shmsegs = newsegs; 710 shmalloced = shminfo.shmmni; 711} 712 713static void 714shminit() 715{ 716 int i; 717 718 shmalloced = shminfo.shmmni; 719 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK); 720 if (shmsegs == NULL) 721 panic("cannot allocate initial memory for sysvshm"); 722 for (i = 0; i < shmalloced; i++) { 723 shmsegs[i].shm_perm.mode = SHMSEG_FREE; 724 shmsegs[i].shm_perm.seq = 0; 725 } 726 shm_last_free = 0; 727 shm_nused = 0; 728 shm_committed = 0; 729 shmexit_hook = &shmexit_myhook; 730 shmfork_hook = &shmfork_myhook; 731} 732 733static int 734shmunload() 735{ 736 737 if (shm_nused > 0) 738 return (EBUSY); 739 740 free(shmsegs, M_SHM); 741 shmexit_hook = NULL; 742 shmfork_hook = NULL; 743 return (0); 744} 745 746static int 747sysctl_shmsegs(SYSCTL_HANDLER_ARGS) 748{ 749 750 return (SYSCTL_OUT(req, shmsegs, shmalloced * sizeof(shmsegs[0]))); 751} 752 753static int 754sysvshm_modload(struct module *module, int cmd, void *arg) 755{ 756 int error = 0; 757 758 switch (cmd) { 759 case MOD_LOAD: 760 shminit(); 761 break; 762 case MOD_UNLOAD: 763 error = shmunload(); 764 break; 765 case MOD_SHUTDOWN: 766 break; 767 default: 768 error = EINVAL; 769 break; 770 } 771 return (error); 772} 773 774static moduledata_t sysvshm_mod = { 775 "sysvshm", 776 &sysvshm_modload, 777 NULL 778}; 779 780SYSCALL_MODULE_HELPER(shmsys, 4); 781SYSCALL_MODULE_HELPER(shmat, 3); 782SYSCALL_MODULE_HELPER(shmctl, 3); 783SYSCALL_MODULE_HELPER(shmdt, 1); 784SYSCALL_MODULE_HELPER(shmget, 3); 785 786DECLARE_MODULE(sysvshm, sysvshm_mod, 787 SI_SUB_SYSV_SHM, SI_ORDER_FIRST); 788MODULE_VERSION(sysvshm, 1); 789