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/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 62 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments"); 63 64 struct oshmctl_args; 65 static int oshmctl __P((struct proc *p, struct oshmctl_args *uap)); 66 67 static int shmget_allocate_segment __P((struct proc *p, 68 struct shmget_args *uap, int mode)); 69 static 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. */ 73 static 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 84 static int shm_last_free, shm_nused, shm_committed, shmalloced; 85 static struct shmid_ds *shmsegs; 86 87 struct shm_handle { 88 /* vm_offset_t kva; */ 89 vm_object_t shm_object; 90 }; 91 92 struct shmmap_state { 93 vm_offset_t va; 94 int shmid; 95 }; 96 97 static void shm_deallocate_segment __P((struct shmid_ds *)); 98 static int shm_find_segment_by_key __P((key_t)); 99 static struct shmid_ds *shm_find_segment_by_shmid __P((int)); 100 static int shm_delete_mapping __P((struct proc *, struct shmmap_state *)); 101 static void shmrealloc __P((void)); 102 static void shminit __P((void)); 103 static int sysvshm_modload __P((struct module *, int, void *)); 104 static int shmunload __P((void)); 105 static void shmexit_myhook __P((struct proc *p)); 106 static void shmfork_myhook __P((struct proc *p1, struct proc *p2)); 107 108 /* 109 * Tuneable values. 110 */ 111 #ifndef SHMMAXPGS 112 #define SHMMAXPGS 8192 /* Note: sysv shared memory is swap backed. */ 113 #endif 114 #ifndef SHMMAX 115 #define SHMMAX (SHMMAXPGS*PAGE_SIZE) 116 #endif 117 #ifndef SHMMIN 118 #define SHMMIN 1 119 #endif 120 #ifndef SHMMNI 121 #define SHMMNI 192 122 #endif 123 #ifndef SHMSEG 124 #define SHMSEG 128 125 #endif 126 #ifndef SHMALL 127 #define SHMALL (SHMMAXPGS) 128 #endif 129 130 struct shminfo shminfo = { 131 SHMMAX, 132 SHMMIN, 133 SHMMNI, 134 SHMSEG, 135 SHMALL 136 }; 137 138 static int shm_use_phys; 139 140 SYSCTL_DECL(_kern_ipc); 141 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0, ""); 142 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0, ""); 143 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RD, &shminfo.shmmni, 0, ""); 144 SYSCTL_INT(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RD, &shminfo.shmseg, 0, ""); 145 SYSCTL_INT(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0, ""); 146 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW, 147 &shm_use_phys, 0, ""); 148 149 static int 150 shm_find_segment_by_key(key) 151 key_t key; 152 { 153 int i; 154 155 for (i = 0; i < shmalloced; i++) 156 if ((shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED) && 157 shmsegs[i].shm_perm.key == key) 158 return i; 159 return -1; 160 } 161 162 static struct shmid_ds * 163 shm_find_segment_by_shmid(shmid) 164 int shmid; 165 { 166 int segnum; 167 struct shmid_ds *shmseg; 168 169 segnum = IPCID_TO_IX(shmid); 170 if (segnum < 0 || segnum >= shmalloced) 171 return NULL; 172 shmseg = &shmsegs[segnum]; 173 if ((shmseg->shm_perm.mode & (SHMSEG_ALLOCATED | SHMSEG_REMOVED)) 174 != SHMSEG_ALLOCATED || 175 shmseg->shm_perm.seq != IPCID_TO_SEQ(shmid)) 176 return NULL; 177 return shmseg; 178 } 179 180 static void 181 shm_deallocate_segment(shmseg) 182 struct shmid_ds *shmseg; 183 { 184 struct shm_handle *shm_handle; 185 size_t size; 186 187 mtx_assert(&vm_mtx, MA_OWNED); /* For vm_object_deallocate. */ 188 shm_handle = shmseg->shm_internal; 189 vm_object_deallocate(shm_handle->shm_object); 190 free((caddr_t)shm_handle, M_SHM); 191 shmseg->shm_internal = NULL; 192 size = round_page(shmseg->shm_segsz); 193 shm_committed -= btoc(size); 194 shm_nused--; 195 shmseg->shm_perm.mode = SHMSEG_FREE; 196 } 197 198 static int 199 shm_delete_mapping(p, shmmap_s) 200 struct proc *p; 201 struct shmmap_state *shmmap_s; 202 { 203 struct shmid_ds *shmseg; 204 int segnum, result; 205 size_t size; 206 207 /* For vm_map_remove and shm_deallocate_segment. */ 208 mtx_assert(&vm_mtx, MA_OWNED); 209 210 segnum = IPCID_TO_IX(shmmap_s->shmid); 211 shmseg = &shmsegs[segnum]; 212 size = round_page(shmseg->shm_segsz); 213 result = vm_map_remove(&p->p_vmspace->vm_map, shmmap_s->va, 214 shmmap_s->va + size); 215 if (result != KERN_SUCCESS) 216 return EINVAL; 217 shmmap_s->shmid = -1; 218 shmseg->shm_dtime = time_second; 219 if ((--shmseg->shm_nattch <= 0) && 220 (shmseg->shm_perm.mode & SHMSEG_REMOVED)) { 221 shm_deallocate_segment(shmseg); 222 shm_last_free = segnum; 223 } 224 return 0; 225 } 226 227 #ifndef _SYS_SYSPROTO_H_ 228 struct shmdt_args { 229 void *shmaddr; 230 }; 231 #endif 232 233 int 234 shmdt(p, uap) 235 struct proc *p; 236 struct shmdt_args *uap; 237 { 238 struct shmmap_state *shmmap_s; 239 int i; 240 int error; 241 242 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) 243 return (ENOSYS); 244 245 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; 246 if (shmmap_s == NULL) 247 return EINVAL; 248 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) 249 if (shmmap_s->shmid != -1 && 250 shmmap_s->va == (vm_offset_t)uap->shmaddr) 251 break; 252 if (i == shminfo.shmseg) 253 return EINVAL; 254 mtx_lock(&vm_mtx); 255 error = shm_delete_mapping(p, shmmap_s); 256 mtx_unlock(&vm_mtx); 257 return error; 258 } 259 260 #ifndef _SYS_SYSPROTO_H_ 261 struct shmat_args { 262 int shmid; 263 void *shmaddr; 264 int shmflg; 265 }; 266 #endif 267 268 int 269 shmat(p, uap) 270 struct proc *p; 271 struct shmat_args *uap; 272 { 273 int error, i, flags; 274 struct shmid_ds *shmseg; 275 struct shmmap_state *shmmap_s = NULL; 276 struct shm_handle *shm_handle; 277 vm_offset_t attach_va; 278 vm_prot_t prot; 279 vm_size_t size; 280 int rv; 281 282 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) 283 return (ENOSYS); 284 285 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; 286 if (shmmap_s == NULL) { 287 size = shminfo.shmseg * sizeof(struct shmmap_state); 288 shmmap_s = malloc(size, M_SHM, M_WAITOK); 289 for (i = 0; i < shminfo.shmseg; i++) 290 shmmap_s[i].shmid = -1; 291 p->p_vmspace->vm_shm = (caddr_t)shmmap_s; 292 } 293 shmseg = shm_find_segment_by_shmid(uap->shmid); 294 if (shmseg == NULL) 295 return EINVAL; 296 error = ipcperm(p, &shmseg->shm_perm, 297 (uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); 298 if (error) 299 return error; 300 for (i = 0; i < shminfo.shmseg; i++) { 301 if (shmmap_s->shmid == -1) 302 break; 303 shmmap_s++; 304 } 305 if (i >= shminfo.shmseg) 306 return EMFILE; 307 size = round_page(shmseg->shm_segsz); 308 #ifdef VM_PROT_READ_IS_EXEC 309 prot = VM_PROT_READ | VM_PROT_EXECUTE; 310 #else 311 prot = VM_PROT_READ; 312 #endif 313 if ((uap->shmflg & SHM_RDONLY) == 0) 314 prot |= VM_PROT_WRITE; 315 flags = MAP_ANON | MAP_SHARED; 316 if (uap->shmaddr) { 317 flags |= MAP_FIXED; 318 if (uap->shmflg & SHM_RND) 319 attach_va = (vm_offset_t)uap->shmaddr & ~(SHMLBA-1); 320 else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0) 321 attach_va = (vm_offset_t)uap->shmaddr; 322 else 323 return EINVAL; 324 } else { 325 /* 326 * This is just a hint to vm_map_find() about where to 327 * put it. 328 */ 329 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_taddr 330 + MAXTSIZ + MAXDSIZ); 331 } 332 333 shm_handle = shmseg->shm_internal; 334 mtx_lock(&vm_mtx); 335 vm_object_reference(shm_handle->shm_object); 336 rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object, 337 0, &attach_va, size, (flags & MAP_FIXED)?0:1, prot, prot, 0); 338 if (rv != KERN_SUCCESS) { 339 mtx_unlock(&vm_mtx); 340 return ENOMEM; 341 } 342 vm_map_inherit(&p->p_vmspace->vm_map, 343 attach_va, attach_va + size, VM_INHERIT_SHARE); 344 mtx_unlock(&vm_mtx); 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 } 354 355 struct 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 }; 366 367 struct oshmctl_args { 368 int shmid; 369 int cmd; 370 struct oshmid_ds *ubuf; 371 }; 372 373 static int 374 oshmctl(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_ 418 struct shmctl_args { 419 int shmid; 420 int cmd; 421 struct shmid_ds *buf; 422 }; 423 #endif 424 425 int 426 shmctl(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 if (!jail_sysvipc_allowed && jailed(p->p_ucred)) 435 return (ENOSYS); 436 437 shmseg = shm_find_segment_by_shmid(uap->shmid); 438 if (shmseg == NULL) 439 return EINVAL; 440 switch (uap->cmd) { 441 case IPC_STAT: 442 error = ipcperm(p, &shmseg->shm_perm, IPC_R); 443 if (error) 444 return error; 445 error = copyout((caddr_t)shmseg, uap->buf, sizeof(inbuf)); 446 if (error) 447 return error; 448 break; 449 case IPC_SET: 450 error = ipcperm(p, &shmseg->shm_perm, IPC_M); 451 if (error) 452 return error; 453 error = copyin(uap->buf, (caddr_t)&inbuf, sizeof(inbuf)); 454 if (error) 455 return error; 456 shmseg->shm_perm.uid = inbuf.shm_perm.uid; 457 shmseg->shm_perm.gid = inbuf.shm_perm.gid; 458 shmseg->shm_perm.mode = 459 (shmseg->shm_perm.mode & ~ACCESSPERMS) | 460 (inbuf.shm_perm.mode & ACCESSPERMS); 461 shmseg->shm_ctime = time_second; 462 break; 463 case IPC_RMID: 464 error = ipcperm(p, &shmseg->shm_perm, IPC_M); 465 if (error) 466 return error; 467 shmseg->shm_perm.key = IPC_PRIVATE; 468 shmseg->shm_perm.mode |= SHMSEG_REMOVED; 469 if (shmseg->shm_nattch <= 0) { 470 mtx_lock(&vm_mtx); 471 shm_deallocate_segment(shmseg); 472 mtx_unlock(&vm_mtx); 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_ 487 struct shmget_args { 488 key_t key; 489 size_t size; 490 int shmflg; 491 }; 492 #endif 493 494 static int 495 shmget_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 } 527 528 static int 529 shmget_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 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) 540 return EINVAL; 541 if (shm_nused >= shminfo.shmmni) /* Any shmids left? */ 542 return ENOSPC; 543 size = round_page(uap->size); 544 if (shm_committed + btoc(size) > shminfo.shmall) 545 return ENOMEM; 546 if (shm_last_free < 0) { 547 shmrealloc(); /* Maybe expand the shmsegs[] array. */ 548 for (i = 0; i < shmalloced; i++) 549 if (shmsegs[i].shm_perm.mode & SHMSEG_FREE) 550 break; 551 if (i == shmalloced) 552 return ENOSPC; 553 segnum = i; 554 } else { 555 segnum = shm_last_free; 556 shm_last_free = -1; 557 } 558 shmseg = &shmsegs[segnum]; 559 /* 560 * In case we sleep in malloc(), mark the segment present but deleted 561 * so that noone else tries to create the same key. 562 */ 563 shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED; 564 shmseg->shm_perm.key = uap->key; 565 shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff; 566 shm_handle = (struct shm_handle *) 567 malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK); 568 shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm); 569 570 /* 571 * We make sure that we have allocated a pager before we need 572 * to. 573 */ 574 mtx_lock(&vm_mtx); 575 if (shm_use_phys) { 576 shm_handle->shm_object = 577 vm_pager_allocate(OBJT_PHYS, 0, size, VM_PROT_DEFAULT, 0); 578 } else { 579 shm_handle->shm_object = 580 vm_pager_allocate(OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0); 581 } 582 vm_object_clear_flag(shm_handle->shm_object, OBJ_ONEMAPPING); 583 vm_object_set_flag(shm_handle->shm_object, OBJ_NOSPLIT); 584 mtx_unlock(&vm_mtx); 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 } 609 610 int 611 shmget(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 } 635 636 int 637 shmsys(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 } 655 656 static void 657 shmfork_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 } 672 673 static void 674 shmexit_myhook(p) 675 struct proc *p; 676 { 677 struct shmmap_state *shmmap_s; 678 int i; 679 680 mtx_assert(&vm_mtx, MA_OWNED); /* For shm_delete_mapping. */ 681 shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; 682 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) 683 if (shmmap_s->shmid != -1) 684 shm_delete_mapping(p, shmmap_s); 685 free((caddr_t)p->p_vmspace->vm_shm, M_SHM); 686 p->p_vmspace->vm_shm = NULL; 687 } 688 689 static void 690 shmrealloc(void) 691 { 692 int i; 693 struct shmid_ds *newsegs; 694 695 if (shmalloced >= shminfo.shmmni) 696 return; 697 698 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK); 699 if (newsegs == NULL) 700 return; 701 for (i = 0; i < shmalloced; i++) 702 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 703 for (; i < shminfo.shmmni; i++) { 704 shmsegs[i].shm_perm.mode = SHMSEG_FREE; 705 shmsegs[i].shm_perm.seq = 0; 706 } 707 free(shmsegs, M_SHM); 708 shmsegs = newsegs; 709 shmalloced = shminfo.shmmni; 710 } 711 712 static void 713 shminit() 714 { 715 int i; 716 717 shmalloced = shminfo.shmmni; 718 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK); 719 if (shmsegs == NULL) 720 panic("cannot allocate initial memory for sysvshm"); 721 for (i = 0; i < shmalloced; i++) { 722 shmsegs[i].shm_perm.mode = SHMSEG_FREE; 723 shmsegs[i].shm_perm.seq = 0; 724 } 725 shm_last_free = 0; 726 shm_nused = 0; 727 shm_committed = 0; 728 shmexit_hook = &shmexit_myhook; 729 shmfork_hook = &shmfork_myhook; 730 } 731 732 static int 733 shmunload() 734 { 735 736 if (shm_nused > 0) 737 return (EBUSY); 738 739 free(shmsegs, M_SHM); 740 shmexit_hook = NULL; 741 shmfork_hook = NULL; 742 return (0); 743 } 744 745 static int 746 sysvshm_modload(struct module *module, int cmd, void *arg) 747 { 748 int error = 0; 749 750 switch (cmd) { 751 case MOD_LOAD: 752 shminit(); 753 break; 754 case MOD_UNLOAD: 755 error = shmunload(); 756 break; 757 case MOD_SHUTDOWN: 758 break; 759 default: 760 error = EINVAL; 761 break; 762 } 763 return (error); 764 } 765 766 static moduledata_t sysvshm_mod = { 767 "sysvshm", 768 &sysvshm_modload, 769 NULL 770 }; 771 772 SYSCALL_MODULE_HELPER(shmsys, 4); 773 SYSCALL_MODULE_HELPER(shmat, 3); 774 SYSCALL_MODULE_HELPER(shmctl, 3); 775 SYSCALL_MODULE_HELPER(shmdt, 1); 776 SYSCALL_MODULE_HELPER(shmget, 3); 777 778 DECLARE_MODULE(sysvshm, sysvshm_mod, 779 SI_SUB_SYSV_SHM, SI_ORDER_FIRST); 780 MODULE_VERSION(sysvshm, 1); 781