Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/sysv_shm.c
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1 /* $NetBSD: sysv_shm.c,v 1.23 1994/07/04 23:25:12 glass Exp $ */ 2 /*- 3 * Copyright (c) 1994 Adam Glass and Charles Hannum. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by Adam Glass and Charles 16 * Hannum. 17 * 4. The names of the authors may not be used to endorse or promote products 18 * derived from this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 */ 31 /*- 32 * Copyright (c) 2003-2005 McAfee, Inc. 33 * All rights reserved. 34 * 35 * This software was developed for the FreeBSD Project in part by McAfee 36 * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR 37 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research 38 * program. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 */ 61 62 #include <sys/cdefs.h> 63 __FBSDID("$FreeBSD$"); 64 65 #include "opt_compat.h" 66 #include "opt_sysvipc.h" 67 68 #include <sys/param.h> 69 #include <sys/systm.h> 70 #include <sys/kernel.h> 71 #include <sys/limits.h> 72 #include <sys/lock.h> 73 #include <sys/sysctl.h> 74 #include <sys/shm.h> 75 #include <sys/proc.h> 76 #include <sys/malloc.h> 77 #include <sys/mman.h> 78 #include <sys/module.h> 79 #include <sys/mutex.h> 80 #include <sys/racct.h> 81 #include <sys/resourcevar.h> 82 #include <sys/rwlock.h> 83 #include <sys/stat.h> 84 #include <sys/syscall.h> 85 #include <sys/syscallsubr.h> 86 #include <sys/sysent.h> 87 #include <sys/sysproto.h> 88 #include <sys/jail.h> 89 90 #include <security/mac/mac_framework.h> 91 92 #include <vm/vm.h> 93 #include <vm/vm_param.h> 94 #include <vm/pmap.h> 95 #include <vm/vm_object.h> 96 #include <vm/vm_map.h> 97 #include <vm/vm_page.h> 98 #include <vm/vm_pager.h> 99 100 FEATURE(sysv_shm, "System V shared memory segments support"); 101 102 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments"); 103 104 static int shmget_allocate_segment(struct thread *td, 105 struct shmget_args *uap, int mode); 106 static int shmget_existing(struct thread *td, struct shmget_args *uap, 107 int mode, int segnum); 108 109 #define SHMSEG_FREE 0x0200 110 #define SHMSEG_REMOVED 0x0400 111 #define SHMSEG_ALLOCATED 0x0800 112 113 static int shm_last_free, shm_nused, shmalloced; 114 vm_size_t shm_committed; 115 static struct shmid_kernel *shmsegs; 116 static unsigned shm_prison_slot; 117 118 struct shmmap_state { 119 vm_offset_t va; 120 int shmid; 121 }; 122 123 static void shm_deallocate_segment(struct shmid_kernel *); 124 static int shm_find_segment_by_key(struct prison *, key_t); 125 static struct shmid_kernel *shm_find_segment(struct prison *, int, bool); 126 static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *); 127 static void shmrealloc(void); 128 static int shminit(void); 129 static int sysvshm_modload(struct module *, int, void *); 130 static int shmunload(void); 131 static void shmexit_myhook(struct vmspace *vm); 132 static void shmfork_myhook(struct proc *p1, struct proc *p2); 133 static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS); 134 static void shm_remove(struct shmid_kernel *, int); 135 static struct prison *shm_find_prison(struct ucred *); 136 static int shm_prison_cansee(struct prison *, struct shmid_kernel *); 137 static int shm_prison_check(void *, void *); 138 static int shm_prison_set(void *, void *); 139 static int shm_prison_get(void *, void *); 140 static int shm_prison_remove(void *, void *); 141 static void shm_prison_cleanup(struct prison *); 142 143 /* 144 * Tuneable values. 145 */ 146 #ifndef SHMMAXPGS 147 #define SHMMAXPGS 131072 /* Note: sysv shared memory is swap backed. */ 148 #endif 149 #ifndef SHMMAX 150 #define SHMMAX (SHMMAXPGS*PAGE_SIZE) 151 #endif 152 #ifndef SHMMIN 153 #define SHMMIN 1 154 #endif 155 #ifndef SHMMNI 156 #define SHMMNI 192 157 #endif 158 #ifndef SHMSEG 159 #define SHMSEG 128 160 #endif 161 #ifndef SHMALL 162 #define SHMALL (SHMMAXPGS) 163 #endif 164 165 struct shminfo shminfo = { 166 SHMMAX, 167 SHMMIN, 168 SHMMNI, 169 SHMSEG, 170 SHMALL 171 }; 172 173 static int shm_use_phys; 174 static int shm_allow_removed; 175 176 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0, 177 "Maximum shared memory segment size"); 178 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0, 179 "Minimum shared memory segment size"); 180 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0, 181 "Number of shared memory identifiers"); 182 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0, 183 "Number of segments per process"); 184 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0, 185 "Maximum number of pages available for shared memory"); 186 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW, 187 &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core"); 188 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RW, 189 &shm_allow_removed, 0, 190 "Enable/Disable attachment to attached segments marked for removal"); 191 SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD | 192 CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "", 193 "Array of struct shmid_kernel for each potential shared memory segment"); 194 195 static struct sx sysvshmsx; 196 #define SYSVSHM_LOCK() sx_xlock(&sysvshmsx) 197 #define SYSVSHM_UNLOCK() sx_xunlock(&sysvshmsx) 198 #define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED) 199 200 static int 201 shm_find_segment_by_key(struct prison *pr, key_t key) 202 { 203 int i; 204 205 for (i = 0; i < shmalloced; i++) 206 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) && 207 shmsegs[i].cred != NULL && 208 shmsegs[i].cred->cr_prison == pr && 209 shmsegs[i].u.shm_perm.key == key) 210 return (i); 211 return (-1); 212 } 213 214 /* 215 * Finds segment either by shmid if is_shmid is true, or by segnum if 216 * is_shmid is false. 217 */ 218 static struct shmid_kernel * 219 shm_find_segment(struct prison *rpr, int arg, bool is_shmid) 220 { 221 struct shmid_kernel *shmseg; 222 int segnum; 223 224 segnum = is_shmid ? IPCID_TO_IX(arg) : arg; 225 if (segnum < 0 || segnum >= shmalloced) 226 return (NULL); 227 shmseg = &shmsegs[segnum]; 228 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 229 (!shm_allow_removed && 230 (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) || 231 (is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg)) || 232 shm_prison_cansee(rpr, shmseg) != 0) 233 return (NULL); 234 return (shmseg); 235 } 236 237 static void 238 shm_deallocate_segment(struct shmid_kernel *shmseg) 239 { 240 vm_size_t size; 241 242 SYSVSHM_ASSERT_LOCKED(); 243 244 vm_object_deallocate(shmseg->object); 245 shmseg->object = NULL; 246 size = round_page(shmseg->u.shm_segsz); 247 shm_committed -= btoc(size); 248 shm_nused--; 249 shmseg->u.shm_perm.mode = SHMSEG_FREE; 250 #ifdef MAC 251 mac_sysvshm_cleanup(shmseg); 252 #endif 253 racct_sub_cred(shmseg->cred, RACCT_NSHM, 1); 254 racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size); 255 crfree(shmseg->cred); 256 shmseg->cred = NULL; 257 } 258 259 static int 260 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s) 261 { 262 struct shmid_kernel *shmseg; 263 int segnum, result; 264 vm_size_t size; 265 266 SYSVSHM_ASSERT_LOCKED(); 267 segnum = IPCID_TO_IX(shmmap_s->shmid); 268 KASSERT(segnum >= 0 && segnum < shmalloced, 269 ("segnum %d shmalloced %d", segnum, shmalloced)); 270 271 shmseg = &shmsegs[segnum]; 272 size = round_page(shmseg->u.shm_segsz); 273 result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size); 274 if (result != KERN_SUCCESS) 275 return (EINVAL); 276 shmmap_s->shmid = -1; 277 shmseg->u.shm_dtime = time_second; 278 if ((--shmseg->u.shm_nattch <= 0) && 279 (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) { 280 shm_deallocate_segment(shmseg); 281 shm_last_free = segnum; 282 } 283 return (0); 284 } 285 286 static void 287 shm_remove(struct shmid_kernel *shmseg, int segnum) 288 { 289 290 shmseg->u.shm_perm.key = IPC_PRIVATE; 291 shmseg->u.shm_perm.mode |= SHMSEG_REMOVED; 292 if (shmseg->u.shm_nattch <= 0) { 293 shm_deallocate_segment(shmseg); 294 shm_last_free = segnum; 295 } 296 } 297 298 static struct prison * 299 shm_find_prison(struct ucred *cred) 300 { 301 struct prison *pr, *rpr; 302 303 pr = cred->cr_prison; 304 prison_lock(pr); 305 rpr = osd_jail_get(pr, shm_prison_slot); 306 prison_unlock(pr); 307 return rpr; 308 } 309 310 static int 311 shm_prison_cansee(struct prison *rpr, struct shmid_kernel *shmseg) 312 { 313 314 if (shmseg->cred == NULL || 315 !(rpr == shmseg->cred->cr_prison || 316 prison_ischild(rpr, shmseg->cred->cr_prison))) 317 return (EINVAL); 318 return (0); 319 } 320 321 static int 322 kern_shmdt_locked(struct thread *td, const void *shmaddr) 323 { 324 struct proc *p = td->td_proc; 325 struct shmmap_state *shmmap_s; 326 #ifdef MAC 327 struct shmid_kernel *shmsegptr; 328 #endif 329 int error, i; 330 331 SYSVSHM_ASSERT_LOCKED(); 332 if (shm_find_prison(td->td_ucred) == NULL) 333 return (ENOSYS); 334 shmmap_s = p->p_vmspace->vm_shm; 335 if (shmmap_s == NULL) 336 return (EINVAL); 337 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 338 if (shmmap_s->shmid != -1 && 339 shmmap_s->va == (vm_offset_t)shmaddr) { 340 break; 341 } 342 } 343 if (i == shminfo.shmseg) 344 return (EINVAL); 345 #ifdef MAC 346 shmsegptr = &shmsegs[IPCID_TO_IX(shmmap_s->shmid)]; 347 error = mac_sysvshm_check_shmdt(td->td_ucred, shmsegptr); 348 if (error != 0) 349 return (error); 350 #endif 351 error = shm_delete_mapping(p->p_vmspace, shmmap_s); 352 return (error); 353 } 354 355 #ifndef _SYS_SYSPROTO_H_ 356 struct shmdt_args { 357 const void *shmaddr; 358 }; 359 #endif 360 int 361 sys_shmdt(struct thread *td, struct shmdt_args *uap) 362 { 363 int error; 364 365 SYSVSHM_LOCK(); 366 error = kern_shmdt_locked(td, uap->shmaddr); 367 SYSVSHM_UNLOCK(); 368 return (error); 369 } 370 371 static int 372 kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr, 373 int shmflg) 374 { 375 struct prison *rpr; 376 struct proc *p = td->td_proc; 377 struct shmid_kernel *shmseg; 378 struct shmmap_state *shmmap_s; 379 vm_offset_t attach_va; 380 vm_prot_t prot; 381 vm_size_t size; 382 int error, i, rv; 383 384 SYSVSHM_ASSERT_LOCKED(); 385 rpr = shm_find_prison(td->td_ucred); 386 if (rpr == NULL) 387 return (ENOSYS); 388 shmmap_s = p->p_vmspace->vm_shm; 389 if (shmmap_s == NULL) { 390 shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state), 391 M_SHM, M_WAITOK); 392 for (i = 0; i < shminfo.shmseg; i++) 393 shmmap_s[i].shmid = -1; 394 KASSERT(p->p_vmspace->vm_shm == NULL, ("raced")); 395 p->p_vmspace->vm_shm = shmmap_s; 396 } 397 shmseg = shm_find_segment(rpr, shmid, true); 398 if (shmseg == NULL) 399 return (EINVAL); 400 error = ipcperm(td, &shmseg->u.shm_perm, 401 (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); 402 if (error != 0) 403 return (error); 404 #ifdef MAC 405 error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg); 406 if (error != 0) 407 return (error); 408 #endif 409 for (i = 0; i < shminfo.shmseg; i++) { 410 if (shmmap_s->shmid == -1) 411 break; 412 shmmap_s++; 413 } 414 if (i >= shminfo.shmseg) 415 return (EMFILE); 416 size = round_page(shmseg->u.shm_segsz); 417 prot = VM_PROT_READ; 418 if ((shmflg & SHM_RDONLY) == 0) 419 prot |= VM_PROT_WRITE; 420 if (shmaddr != NULL) { 421 if ((shmflg & SHM_RND) != 0) 422 attach_va = (vm_offset_t)shmaddr & ~(SHMLBA-1); 423 else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0) 424 attach_va = (vm_offset_t)shmaddr; 425 else 426 return (EINVAL); 427 } else { 428 /* 429 * This is just a hint to vm_map_find() about where to 430 * put it. 431 */ 432 PROC_LOCK(p); 433 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 434 lim_max(p, RLIMIT_DATA)); 435 PROC_UNLOCK(p); 436 } 437 438 vm_object_reference(shmseg->object); 439 rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object, 440 0, &attach_va, size, 0, shmaddr != NULL ? VMFS_NO_SPACE : 441 VMFS_OPTIMAL_SPACE, prot, prot, MAP_INHERIT_SHARE); 442 if (rv != KERN_SUCCESS) { 443 vm_object_deallocate(shmseg->object); 444 return (ENOMEM); 445 } 446 447 shmmap_s->va = attach_va; 448 shmmap_s->shmid = shmid; 449 shmseg->u.shm_lpid = p->p_pid; 450 shmseg->u.shm_atime = time_second; 451 shmseg->u.shm_nattch++; 452 td->td_retval[0] = attach_va; 453 return (error); 454 } 455 456 int 457 kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg) 458 { 459 int error; 460 461 SYSVSHM_LOCK(); 462 error = kern_shmat_locked(td, shmid, shmaddr, shmflg); 463 SYSVSHM_UNLOCK(); 464 return (error); 465 } 466 467 #ifndef _SYS_SYSPROTO_H_ 468 struct shmat_args { 469 int shmid; 470 const void *shmaddr; 471 int shmflg; 472 }; 473 #endif 474 int 475 sys_shmat(struct thread *td, struct shmat_args *uap) 476 { 477 478 return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg)); 479 } 480 481 static int 482 kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf, 483 size_t *bufsz) 484 { 485 struct prison *rpr; 486 struct shmid_kernel *shmseg; 487 struct shmid_ds *shmidp; 488 struct shm_info shm_info; 489 int error; 490 491 SYSVSHM_ASSERT_LOCKED(); 492 493 rpr = shm_find_prison(td->td_ucred); 494 if (rpr == NULL) 495 return (ENOSYS); 496 497 error = 0; 498 switch (cmd) { 499 /* 500 * It is possible that kern_shmctl is being called from the Linux ABI 501 * layer, in which case, we will need to implement IPC_INFO. It should 502 * be noted that other shmctl calls will be funneled through here for 503 * Linix binaries as well. 504 * 505 * NB: The Linux ABI layer will convert this data to structure(s) more 506 * consistent with the Linux ABI. 507 */ 508 case IPC_INFO: 509 memcpy(buf, &shminfo, sizeof(shminfo)); 510 if (bufsz) 511 *bufsz = sizeof(shminfo); 512 td->td_retval[0] = shmalloced; 513 return (0); 514 case SHM_INFO: { 515 shm_info.used_ids = shm_nused; 516 shm_info.shm_rss = 0; /*XXX where to get from ? */ 517 shm_info.shm_tot = 0; /*XXX where to get from ? */ 518 shm_info.shm_swp = 0; /*XXX where to get from ? */ 519 shm_info.swap_attempts = 0; /*XXX where to get from ? */ 520 shm_info.swap_successes = 0; /*XXX where to get from ? */ 521 memcpy(buf, &shm_info, sizeof(shm_info)); 522 if (bufsz != NULL) 523 *bufsz = sizeof(shm_info); 524 td->td_retval[0] = shmalloced; 525 return (0); 526 } 527 } 528 shmseg = shm_find_segment(rpr, shmid, cmd != SHM_STAT); 529 if (shmseg == NULL) 530 return (EINVAL); 531 #ifdef MAC 532 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd); 533 if (error != 0) 534 return (error); 535 #endif 536 switch (cmd) { 537 case SHM_STAT: 538 case IPC_STAT: 539 shmidp = (struct shmid_ds *)buf; 540 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 541 if (error != 0) 542 return (error); 543 memcpy(shmidp, &shmseg->u, sizeof(struct shmid_ds)); 544 if (td->td_ucred->cr_prison != shmseg->cred->cr_prison) 545 shmidp->shm_perm.key = IPC_PRIVATE; 546 if (bufsz != NULL) 547 *bufsz = sizeof(struct shmid_ds); 548 if (cmd == SHM_STAT) { 549 td->td_retval[0] = IXSEQ_TO_IPCID(shmid, 550 shmseg->u.shm_perm); 551 } 552 break; 553 case IPC_SET: 554 shmidp = (struct shmid_ds *)buf; 555 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); 556 if (error != 0) 557 return (error); 558 shmseg->u.shm_perm.uid = shmidp->shm_perm.uid; 559 shmseg->u.shm_perm.gid = shmidp->shm_perm.gid; 560 shmseg->u.shm_perm.mode = 561 (shmseg->u.shm_perm.mode & ~ACCESSPERMS) | 562 (shmidp->shm_perm.mode & ACCESSPERMS); 563 shmseg->u.shm_ctime = time_second; 564 break; 565 case IPC_RMID: 566 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); 567 if (error != 0) 568 return (error); 569 shm_remove(shmseg, IPCID_TO_IX(shmid)); 570 break; 571 #if 0 572 case SHM_LOCK: 573 case SHM_UNLOCK: 574 #endif 575 default: 576 error = EINVAL; 577 break; 578 } 579 return (error); 580 } 581 582 int 583 kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz) 584 { 585 int error; 586 587 SYSVSHM_LOCK(); 588 error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz); 589 SYSVSHM_UNLOCK(); 590 return (error); 591 } 592 593 594 #ifndef _SYS_SYSPROTO_H_ 595 struct shmctl_args { 596 int shmid; 597 int cmd; 598 struct shmid_ds *buf; 599 }; 600 #endif 601 int 602 sys_shmctl(struct thread *td, struct shmctl_args *uap) 603 { 604 int error = 0; 605 struct shmid_ds buf; 606 size_t bufsz; 607 608 /* 609 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 610 * Linux binaries. If we see the call come through the FreeBSD ABI, 611 * return an error back to the user since we do not to support this. 612 */ 613 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 614 uap->cmd == SHM_STAT) 615 return (EINVAL); 616 617 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 618 if (uap->cmd == IPC_SET) { 619 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds)))) 620 goto done; 621 } 622 623 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 624 if (error) 625 goto done; 626 627 /* Cases in which we need to copyout */ 628 switch (uap->cmd) { 629 case IPC_STAT: 630 error = copyout(&buf, uap->buf, bufsz); 631 break; 632 } 633 634 done: 635 if (error) { 636 /* Invalidate the return value */ 637 td->td_retval[0] = -1; 638 } 639 return (error); 640 } 641 642 643 static int 644 shmget_existing(struct thread *td, struct shmget_args *uap, int mode, 645 int segnum) 646 { 647 struct shmid_kernel *shmseg; 648 #ifdef MAC 649 int error; 650 #endif 651 652 SYSVSHM_ASSERT_LOCKED(); 653 KASSERT(segnum >= 0 && segnum < shmalloced, 654 ("segnum %d shmalloced %d", segnum, shmalloced)); 655 shmseg = &shmsegs[segnum]; 656 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) 657 return (EEXIST); 658 #ifdef MAC 659 error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg); 660 if (error != 0) 661 return (error); 662 #endif 663 if (uap->size != 0 && uap->size > shmseg->u.shm_segsz) 664 return (EINVAL); 665 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 666 return (0); 667 } 668 669 static int 670 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode) 671 { 672 struct ucred *cred = td->td_ucred; 673 struct shmid_kernel *shmseg; 674 vm_object_t shm_object; 675 int i, segnum; 676 size_t size; 677 678 SYSVSHM_ASSERT_LOCKED(); 679 680 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) 681 return (EINVAL); 682 if (shm_nused >= shminfo.shmmni) /* Any shmids left? */ 683 return (ENOSPC); 684 size = round_page(uap->size); 685 if (shm_committed + btoc(size) > shminfo.shmall) 686 return (ENOMEM); 687 if (shm_last_free < 0) { 688 shmrealloc(); /* Maybe expand the shmsegs[] array. */ 689 for (i = 0; i < shmalloced; i++) 690 if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE) 691 break; 692 if (i == shmalloced) 693 return (ENOSPC); 694 segnum = i; 695 } else { 696 segnum = shm_last_free; 697 shm_last_free = -1; 698 } 699 KASSERT(segnum >= 0 && segnum < shmalloced, 700 ("segnum %d shmalloced %d", segnum, shmalloced)); 701 shmseg = &shmsegs[segnum]; 702 #ifdef RACCT 703 if (racct_enable) { 704 PROC_LOCK(td->td_proc); 705 if (racct_add(td->td_proc, RACCT_NSHM, 1)) { 706 PROC_UNLOCK(td->td_proc); 707 return (ENOSPC); 708 } 709 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) { 710 racct_sub(td->td_proc, RACCT_NSHM, 1); 711 PROC_UNLOCK(td->td_proc); 712 return (ENOMEM); 713 } 714 PROC_UNLOCK(td->td_proc); 715 } 716 #endif 717 718 /* 719 * We make sure that we have allocated a pager before we need 720 * to. 721 */ 722 shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP, 723 0, size, VM_PROT_DEFAULT, 0, cred); 724 if (shm_object == NULL) { 725 #ifdef RACCT 726 if (racct_enable) { 727 PROC_LOCK(td->td_proc); 728 racct_sub(td->td_proc, RACCT_NSHM, 1); 729 racct_sub(td->td_proc, RACCT_SHMSIZE, size); 730 PROC_UNLOCK(td->td_proc); 731 } 732 #endif 733 return (ENOMEM); 734 } 735 shm_object->pg_color = 0; 736 VM_OBJECT_WLOCK(shm_object); 737 vm_object_clear_flag(shm_object, OBJ_ONEMAPPING); 738 vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT); 739 VM_OBJECT_WUNLOCK(shm_object); 740 741 shmseg->object = shm_object; 742 shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid; 743 shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid; 744 shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; 745 shmseg->u.shm_perm.key = uap->key; 746 shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff; 747 shmseg->cred = crhold(cred); 748 shmseg->u.shm_segsz = uap->size; 749 shmseg->u.shm_cpid = td->td_proc->p_pid; 750 shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0; 751 shmseg->u.shm_atime = shmseg->u.shm_dtime = 0; 752 #ifdef MAC 753 mac_sysvshm_create(cred, shmseg); 754 #endif 755 shmseg->u.shm_ctime = time_second; 756 shm_committed += btoc(size); 757 shm_nused++; 758 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 759 760 return (0); 761 } 762 763 #ifndef _SYS_SYSPROTO_H_ 764 struct shmget_args { 765 key_t key; 766 size_t size; 767 int shmflg; 768 }; 769 #endif 770 int 771 sys_shmget(struct thread *td, struct shmget_args *uap) 772 { 773 int segnum, mode; 774 int error; 775 776 if (shm_find_prison(td->td_ucred) == NULL) 777 return (ENOSYS); 778 mode = uap->shmflg & ACCESSPERMS; 779 SYSVSHM_LOCK(); 780 if (uap->key == IPC_PRIVATE) { 781 error = shmget_allocate_segment(td, uap, mode); 782 } else { 783 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison, 784 uap->key); 785 if (segnum >= 0) 786 error = shmget_existing(td, uap, mode, segnum); 787 else if ((uap->shmflg & IPC_CREAT) == 0) 788 error = ENOENT; 789 else 790 error = shmget_allocate_segment(td, uap, mode); 791 } 792 SYSVSHM_UNLOCK(); 793 return (error); 794 } 795 796 static void 797 shmfork_myhook(struct proc *p1, struct proc *p2) 798 { 799 struct shmmap_state *shmmap_s; 800 size_t size; 801 int i; 802 803 SYSVSHM_LOCK(); 804 size = shminfo.shmseg * sizeof(struct shmmap_state); 805 shmmap_s = malloc(size, M_SHM, M_WAITOK); 806 bcopy(p1->p_vmspace->vm_shm, shmmap_s, size); 807 p2->p_vmspace->vm_shm = shmmap_s; 808 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 809 if (shmmap_s->shmid != -1) { 810 KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 && 811 IPCID_TO_IX(shmmap_s->shmid) < shmalloced, 812 ("segnum %d shmalloced %d", 813 IPCID_TO_IX(shmmap_s->shmid), shmalloced)); 814 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++; 815 } 816 } 817 SYSVSHM_UNLOCK(); 818 } 819 820 static void 821 shmexit_myhook(struct vmspace *vm) 822 { 823 struct shmmap_state *base, *shm; 824 int i; 825 826 base = vm->vm_shm; 827 if (base != NULL) { 828 vm->vm_shm = NULL; 829 SYSVSHM_LOCK(); 830 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) { 831 if (shm->shmid != -1) 832 shm_delete_mapping(vm, shm); 833 } 834 SYSVSHM_UNLOCK(); 835 free(base, M_SHM); 836 } 837 } 838 839 static void 840 shmrealloc(void) 841 { 842 struct shmid_kernel *newsegs; 843 int i; 844 845 SYSVSHM_ASSERT_LOCKED(); 846 847 if (shmalloced >= shminfo.shmmni) 848 return; 849 850 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK); 851 for (i = 0; i < shmalloced; i++) 852 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 853 for (; i < shminfo.shmmni; i++) { 854 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; 855 shmsegs[i].u.shm_perm.seq = 0; 856 #ifdef MAC 857 mac_sysvshm_init(&shmsegs[i]); 858 #endif 859 } 860 free(shmsegs, M_SHM); 861 shmsegs = newsegs; 862 shmalloced = shminfo.shmmni; 863 } 864 865 static struct syscall_helper_data shm_syscalls[] = { 866 SYSCALL_INIT_HELPER(shmat), 867 SYSCALL_INIT_HELPER(shmctl), 868 SYSCALL_INIT_HELPER(shmdt), 869 SYSCALL_INIT_HELPER(shmget), 870 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 871 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 872 SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl), 873 #endif 874 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 875 SYSCALL_INIT_HELPER(shmsys), 876 #endif 877 SYSCALL_INIT_LAST 878 }; 879 880 #ifdef COMPAT_FREEBSD32 881 #include <compat/freebsd32/freebsd32.h> 882 #include <compat/freebsd32/freebsd32_ipc.h> 883 #include <compat/freebsd32/freebsd32_proto.h> 884 #include <compat/freebsd32/freebsd32_signal.h> 885 #include <compat/freebsd32/freebsd32_syscall.h> 886 #include <compat/freebsd32/freebsd32_util.h> 887 888 static struct syscall_helper_data shm32_syscalls[] = { 889 SYSCALL32_INIT_HELPER_COMPAT(shmat), 890 SYSCALL32_INIT_HELPER_COMPAT(shmdt), 891 SYSCALL32_INIT_HELPER_COMPAT(shmget), 892 SYSCALL32_INIT_HELPER(freebsd32_shmsys), 893 SYSCALL32_INIT_HELPER(freebsd32_shmctl), 894 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 895 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 896 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl), 897 #endif 898 SYSCALL_INIT_LAST 899 }; 900 #endif 901 902 static int 903 shminit(void) 904 { 905 struct prison *pr; 906 void *rsv; 907 int i, error; 908 osd_method_t methods[PR_MAXMETHOD] = { 909 [PR_METHOD_CHECK] = shm_prison_check, 910 [PR_METHOD_SET] = shm_prison_set, 911 [PR_METHOD_GET] = shm_prison_get, 912 [PR_METHOD_REMOVE] = shm_prison_remove, 913 }; 914 915 #ifndef BURN_BRIDGES 916 if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0) 917 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n"); 918 #endif 919 TUNABLE_ULONG_FETCH("kern.ipc.shmall", &shminfo.shmall); 920 if (!TUNABLE_ULONG_FETCH("kern.ipc.shmmax", &shminfo.shmmax)) { 921 /* Initialize shmmax dealing with possible overflow. */ 922 for (i = PAGE_SIZE; i > 0; i--) { 923 shminfo.shmmax = shminfo.shmall * i; 924 if (shminfo.shmmax >= shminfo.shmall) 925 break; 926 } 927 } 928 TUNABLE_ULONG_FETCH("kern.ipc.shmmin", &shminfo.shmmin); 929 TUNABLE_ULONG_FETCH("kern.ipc.shmmni", &shminfo.shmmni); 930 TUNABLE_ULONG_FETCH("kern.ipc.shmseg", &shminfo.shmseg); 931 TUNABLE_INT_FETCH("kern.ipc.shm_use_phys", &shm_use_phys); 932 933 shmalloced = shminfo.shmmni; 934 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK); 935 for (i = 0; i < shmalloced; i++) { 936 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; 937 shmsegs[i].u.shm_perm.seq = 0; 938 #ifdef MAC 939 mac_sysvshm_init(&shmsegs[i]); 940 #endif 941 } 942 shm_last_free = 0; 943 shm_nused = 0; 944 shm_committed = 0; 945 sx_init(&sysvshmsx, "sysvshmsx"); 946 shmexit_hook = &shmexit_myhook; 947 shmfork_hook = &shmfork_myhook; 948 949 /* Set current prisons according to their allow.sysvipc. */ 950 shm_prison_slot = osd_jail_register(NULL, methods); 951 rsv = osd_reserve(shm_prison_slot); 952 prison_lock(&prison0); 953 (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0); 954 prison_unlock(&prison0); 955 rsv = NULL; 956 sx_slock(&allprison_lock); 957 TAILQ_FOREACH(pr, &allprison, pr_list) { 958 if (rsv == NULL) 959 rsv = osd_reserve(shm_prison_slot); 960 prison_lock(pr); 961 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) { 962 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 963 &prison0); 964 rsv = NULL; 965 } 966 prison_unlock(pr); 967 } 968 if (rsv != NULL) 969 osd_free_reserved(rsv); 970 sx_sunlock(&allprison_lock); 971 972 error = syscall_helper_register(shm_syscalls); 973 if (error != 0) 974 return (error); 975 #ifdef COMPAT_FREEBSD32 976 error = syscall32_helper_register(shm32_syscalls); 977 if (error != 0) 978 return (error); 979 #endif 980 return (0); 981 } 982 983 static int 984 shmunload(void) 985 { 986 int i; 987 988 if (shm_nused > 0) 989 return (EBUSY); 990 991 #ifdef COMPAT_FREEBSD32 992 syscall32_helper_unregister(shm32_syscalls); 993 #endif 994 syscall_helper_unregister(shm_syscalls); 995 if (shm_prison_slot != 0) 996 osd_jail_deregister(shm_prison_slot); 997 998 for (i = 0; i < shmalloced; i++) { 999 #ifdef MAC 1000 mac_sysvshm_destroy(&shmsegs[i]); 1001 #endif 1002 /* 1003 * Objects might be still mapped into the processes 1004 * address spaces. Actual free would happen on the 1005 * last mapping destruction. 1006 */ 1007 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE) 1008 vm_object_deallocate(shmsegs[i].object); 1009 } 1010 free(shmsegs, M_SHM); 1011 shmexit_hook = NULL; 1012 shmfork_hook = NULL; 1013 sx_destroy(&sysvshmsx); 1014 return (0); 1015 } 1016 1017 static int 1018 sysctl_shmsegs(SYSCTL_HANDLER_ARGS) 1019 { 1020 struct shmid_kernel tshmseg; 1021 struct prison *pr, *rpr; 1022 int error, i; 1023 1024 SYSVSHM_LOCK(); 1025 pr = req->td->td_ucred->cr_prison; 1026 rpr = shm_find_prison(req->td->td_ucred); 1027 error = 0; 1028 for (i = 0; i < shmalloced; i++) { 1029 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 1030 rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) { 1031 bzero(&tshmseg, sizeof(tshmseg)); 1032 tshmseg.u.shm_perm.mode = SHMSEG_FREE; 1033 } else { 1034 tshmseg = shmsegs[i]; 1035 if (tshmseg.cred->cr_prison != pr) 1036 tshmseg.u.shm_perm.key = IPC_PRIVATE; 1037 } 1038 error = SYSCTL_OUT(req, &tshmseg, sizeof(tshmseg)); 1039 if (error != 0) 1040 break; 1041 } 1042 SYSVSHM_UNLOCK(); 1043 return (error); 1044 } 1045 1046 static int 1047 shm_prison_check(void *obj, void *data) 1048 { 1049 struct prison *pr = obj; 1050 struct prison *prpr; 1051 struct vfsoptlist *opts = data; 1052 int error, jsys; 1053 1054 /* 1055 * sysvshm is a jailsys integer. 1056 * It must be "disable" if the parent jail is disabled. 1057 */ 1058 error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1059 if (error != ENOENT) { 1060 if (error != 0) 1061 return (error); 1062 switch (jsys) { 1063 case JAIL_SYS_DISABLE: 1064 break; 1065 case JAIL_SYS_NEW: 1066 case JAIL_SYS_INHERIT: 1067 prison_lock(pr->pr_parent); 1068 prpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1069 prison_unlock(pr->pr_parent); 1070 if (prpr == NULL) 1071 return (EPERM); 1072 break; 1073 default: 1074 return (EINVAL); 1075 } 1076 } 1077 1078 return (0); 1079 } 1080 1081 static int 1082 shm_prison_set(void *obj, void *data) 1083 { 1084 struct prison *pr = obj; 1085 struct prison *tpr, *orpr, *nrpr, *trpr; 1086 struct vfsoptlist *opts = data; 1087 void *rsv; 1088 int jsys, descend; 1089 1090 /* 1091 * sysvshm controls which jail is the root of the associated segments 1092 * (this jail or same as the parent), or if the feature is available 1093 * at all. 1094 */ 1095 if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT) 1096 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0) 1097 ? JAIL_SYS_INHERIT 1098 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0) 1099 ? JAIL_SYS_DISABLE 1100 : -1; 1101 if (jsys == JAIL_SYS_DISABLE) { 1102 prison_lock(pr); 1103 orpr = osd_jail_get(pr, shm_prison_slot); 1104 if (orpr != NULL) 1105 osd_jail_del(pr, shm_prison_slot); 1106 prison_unlock(pr); 1107 if (orpr != NULL) { 1108 if (orpr == pr) 1109 shm_prison_cleanup(pr); 1110 /* Disable all child jails as well. */ 1111 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1112 prison_lock(tpr); 1113 trpr = osd_jail_get(tpr, shm_prison_slot); 1114 if (trpr != NULL) { 1115 osd_jail_del(tpr, shm_prison_slot); 1116 prison_unlock(tpr); 1117 if (trpr == tpr) 1118 shm_prison_cleanup(tpr); 1119 } else { 1120 prison_unlock(tpr); 1121 descend = 0; 1122 } 1123 } 1124 } 1125 } else if (jsys != -1) { 1126 if (jsys == JAIL_SYS_NEW) 1127 nrpr = pr; 1128 else { 1129 prison_lock(pr->pr_parent); 1130 nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1131 prison_unlock(pr->pr_parent); 1132 } 1133 rsv = osd_reserve(shm_prison_slot); 1134 prison_lock(pr); 1135 orpr = osd_jail_get(pr, shm_prison_slot); 1136 if (orpr != nrpr) 1137 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 1138 nrpr); 1139 else 1140 osd_free_reserved(rsv); 1141 prison_unlock(pr); 1142 if (orpr != nrpr) { 1143 if (orpr == pr) 1144 shm_prison_cleanup(pr); 1145 if (orpr != NULL) { 1146 /* Change child jails matching the old root, */ 1147 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1148 prison_lock(tpr); 1149 trpr = osd_jail_get(tpr, 1150 shm_prison_slot); 1151 if (trpr == orpr) { 1152 (void)osd_jail_set(tpr, 1153 shm_prison_slot, nrpr); 1154 prison_unlock(tpr); 1155 if (trpr == tpr) 1156 shm_prison_cleanup(tpr); 1157 } else { 1158 prison_unlock(tpr); 1159 descend = 0; 1160 } 1161 } 1162 } 1163 } 1164 } 1165 1166 return (0); 1167 } 1168 1169 static int 1170 shm_prison_get(void *obj, void *data) 1171 { 1172 struct prison *pr = obj; 1173 struct prison *rpr; 1174 struct vfsoptlist *opts = data; 1175 int error, jsys; 1176 1177 /* Set sysvshm based on the jail's root prison. */ 1178 prison_lock(pr); 1179 rpr = osd_jail_get(pr, shm_prison_slot); 1180 prison_unlock(pr); 1181 jsys = rpr == NULL ? JAIL_SYS_DISABLE 1182 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT; 1183 error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1184 if (error == ENOENT) 1185 error = 0; 1186 return (error); 1187 } 1188 1189 static int 1190 shm_prison_remove(void *obj, void *data __unused) 1191 { 1192 struct prison *pr = obj; 1193 struct prison *rpr; 1194 1195 SYSVSHM_LOCK(); 1196 prison_lock(pr); 1197 rpr = osd_jail_get(pr, shm_prison_slot); 1198 prison_unlock(pr); 1199 if (rpr == pr) 1200 shm_prison_cleanup(pr); 1201 SYSVSHM_UNLOCK(); 1202 return (0); 1203 } 1204 1205 static void 1206 shm_prison_cleanup(struct prison *pr) 1207 { 1208 struct shmid_kernel *shmseg; 1209 int i; 1210 1211 /* Remove any segments that belong to this jail. */ 1212 for (i = 0; i < shmalloced; i++) { 1213 shmseg = &shmsegs[i]; 1214 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) && 1215 shmseg->cred != NULL && shmseg->cred->cr_prison == pr) { 1216 shm_remove(shmseg, i); 1217 } 1218 } 1219 } 1220 1221 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory"); 1222 1223 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 1224 struct oshmid_ds { 1225 struct ipc_perm_old shm_perm; /* operation perms */ 1226 int shm_segsz; /* size of segment (bytes) */ 1227 u_short shm_cpid; /* pid, creator */ 1228 u_short shm_lpid; /* pid, last operation */ 1229 short shm_nattch; /* no. of current attaches */ 1230 time_t shm_atime; /* last attach time */ 1231 time_t shm_dtime; /* last detach time */ 1232 time_t shm_ctime; /* last change time */ 1233 void *shm_handle; /* internal handle for shm segment */ 1234 }; 1235 1236 struct oshmctl_args { 1237 int shmid; 1238 int cmd; 1239 struct oshmid_ds *ubuf; 1240 }; 1241 1242 static int 1243 oshmctl(struct thread *td, struct oshmctl_args *uap) 1244 { 1245 #ifdef COMPAT_43 1246 int error = 0; 1247 struct prison *rpr; 1248 struct shmid_kernel *shmseg; 1249 struct oshmid_ds outbuf; 1250 1251 rpr = shm_find_prison(td->td_ucred); 1252 if (rpr == NULL) 1253 return (ENOSYS); 1254 if (uap->cmd != IPC_STAT) { 1255 return (freebsd7_shmctl(td, 1256 (struct freebsd7_shmctl_args *)uap)); 1257 } 1258 SYSVSHM_LOCK(); 1259 shmseg = shm_find_segment(rpr, uap->shmid, true); 1260 if (shmseg == NULL) { 1261 SYSVSHM_UNLOCK(); 1262 return (EINVAL); 1263 } 1264 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 1265 if (error != 0) { 1266 SYSVSHM_UNLOCK(); 1267 return (error); 1268 } 1269 #ifdef MAC 1270 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd); 1271 if (error != 0) { 1272 SYSVSHM_UNLOCK(); 1273 return (error); 1274 } 1275 #endif 1276 ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm); 1277 outbuf.shm_segsz = shmseg->u.shm_segsz; 1278 outbuf.shm_cpid = shmseg->u.shm_cpid; 1279 outbuf.shm_lpid = shmseg->u.shm_lpid; 1280 outbuf.shm_nattch = shmseg->u.shm_nattch; 1281 outbuf.shm_atime = shmseg->u.shm_atime; 1282 outbuf.shm_dtime = shmseg->u.shm_dtime; 1283 outbuf.shm_ctime = shmseg->u.shm_ctime; 1284 outbuf.shm_handle = shmseg->object; 1285 SYSVSHM_UNLOCK(); 1286 error = copyout(&outbuf, uap->ubuf, sizeof(outbuf)); 1287 return (error); 1288 #else 1289 return (EINVAL); 1290 #endif 1291 } 1292 1293 /* XXX casting to (sy_call_t *) is bogus, as usual. */ 1294 static sy_call_t *shmcalls[] = { 1295 (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl, 1296 (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget, 1297 (sy_call_t *)freebsd7_shmctl 1298 }; 1299 1300 #ifndef _SYS_SYSPROTO_H_ 1301 /* XXX actually varargs. */ 1302 struct shmsys_args { 1303 int which; 1304 int a2; 1305 int a3; 1306 int a4; 1307 }; 1308 #endif 1309 int 1310 sys_shmsys(struct thread *td, struct shmsys_args *uap) 1311 { 1312 int error; 1313 1314 if (uap->which < 0 || uap->which >= nitems(shmcalls)) 1315 return (EINVAL); 1316 error = (*shmcalls[uap->which])(td, &uap->a2); 1317 return (error); 1318 } 1319 1320 #endif /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */ 1321 1322 #ifdef COMPAT_FREEBSD32 1323 1324 int 1325 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap) 1326 { 1327 1328 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1329 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1330 switch (uap->which) { 1331 case 0: { /* shmat */ 1332 struct shmat_args ap; 1333 1334 ap.shmid = uap->a2; 1335 ap.shmaddr = PTRIN(uap->a3); 1336 ap.shmflg = uap->a4; 1337 return (sysent[SYS_shmat].sy_call(td, &ap)); 1338 } 1339 case 2: { /* shmdt */ 1340 struct shmdt_args ap; 1341 1342 ap.shmaddr = PTRIN(uap->a2); 1343 return (sysent[SYS_shmdt].sy_call(td, &ap)); 1344 } 1345 case 3: { /* shmget */ 1346 struct shmget_args ap; 1347 1348 ap.key = uap->a2; 1349 ap.size = uap->a3; 1350 ap.shmflg = uap->a4; 1351 return (sysent[SYS_shmget].sy_call(td, &ap)); 1352 } 1353 case 4: { /* shmctl */ 1354 struct freebsd7_freebsd32_shmctl_args ap; 1355 1356 ap.shmid = uap->a2; 1357 ap.cmd = uap->a3; 1358 ap.buf = PTRIN(uap->a4); 1359 return (freebsd7_freebsd32_shmctl(td, &ap)); 1360 } 1361 case 1: /* oshmctl */ 1362 default: 1363 return (EINVAL); 1364 } 1365 #else 1366 return (nosys(td, NULL)); 1367 #endif 1368 } 1369 1370 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1371 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1372 int 1373 freebsd7_freebsd32_shmctl(struct thread *td, 1374 struct freebsd7_freebsd32_shmctl_args *uap) 1375 { 1376 int error = 0; 1377 union { 1378 struct shmid_ds shmid_ds; 1379 struct shm_info shm_info; 1380 struct shminfo shminfo; 1381 } u; 1382 union { 1383 struct shmid_ds32_old shmid_ds32; 1384 struct shm_info32 shm_info32; 1385 struct shminfo32 shminfo32; 1386 } u32; 1387 size_t sz; 1388 1389 if (uap->cmd == IPC_SET) { 1390 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1391 sizeof(u32.shmid_ds32)))) 1392 goto done; 1393 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm, 1394 &u.shmid_ds.shm_perm); 1395 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1396 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1397 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1398 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1399 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1400 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1401 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1402 } 1403 1404 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1405 if (error) 1406 goto done; 1407 1408 /* Cases in which we need to copyout */ 1409 switch (uap->cmd) { 1410 case IPC_INFO: 1411 CP(u.shminfo, u32.shminfo32, shmmax); 1412 CP(u.shminfo, u32.shminfo32, shmmin); 1413 CP(u.shminfo, u32.shminfo32, shmmni); 1414 CP(u.shminfo, u32.shminfo32, shmseg); 1415 CP(u.shminfo, u32.shminfo32, shmall); 1416 error = copyout(&u32.shminfo32, uap->buf, 1417 sizeof(u32.shminfo32)); 1418 break; 1419 case SHM_INFO: 1420 CP(u.shm_info, u32.shm_info32, used_ids); 1421 CP(u.shm_info, u32.shm_info32, shm_rss); 1422 CP(u.shm_info, u32.shm_info32, shm_tot); 1423 CP(u.shm_info, u32.shm_info32, shm_swp); 1424 CP(u.shm_info, u32.shm_info32, swap_attempts); 1425 CP(u.shm_info, u32.shm_info32, swap_successes); 1426 error = copyout(&u32.shm_info32, uap->buf, 1427 sizeof(u32.shm_info32)); 1428 break; 1429 case SHM_STAT: 1430 case IPC_STAT: 1431 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm, 1432 &u32.shmid_ds32.shm_perm); 1433 if (u.shmid_ds.shm_segsz > INT32_MAX) 1434 u32.shmid_ds32.shm_segsz = INT32_MAX; 1435 else 1436 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1437 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1438 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1439 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1440 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1441 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1442 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1443 u32.shmid_ds32.shm_internal = 0; 1444 error = copyout(&u32.shmid_ds32, uap->buf, 1445 sizeof(u32.shmid_ds32)); 1446 break; 1447 } 1448 1449 done: 1450 if (error) { 1451 /* Invalidate the return value */ 1452 td->td_retval[0] = -1; 1453 } 1454 return (error); 1455 } 1456 #endif 1457 1458 int 1459 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap) 1460 { 1461 int error = 0; 1462 union { 1463 struct shmid_ds shmid_ds; 1464 struct shm_info shm_info; 1465 struct shminfo shminfo; 1466 } u; 1467 union { 1468 struct shmid_ds32 shmid_ds32; 1469 struct shm_info32 shm_info32; 1470 struct shminfo32 shminfo32; 1471 } u32; 1472 size_t sz; 1473 1474 if (uap->cmd == IPC_SET) { 1475 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1476 sizeof(u32.shmid_ds32)))) 1477 goto done; 1478 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm, 1479 &u.shmid_ds.shm_perm); 1480 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1481 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1482 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1483 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1484 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1485 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1486 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1487 } 1488 1489 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1490 if (error) 1491 goto done; 1492 1493 /* Cases in which we need to copyout */ 1494 switch (uap->cmd) { 1495 case IPC_INFO: 1496 CP(u.shminfo, u32.shminfo32, shmmax); 1497 CP(u.shminfo, u32.shminfo32, shmmin); 1498 CP(u.shminfo, u32.shminfo32, shmmni); 1499 CP(u.shminfo, u32.shminfo32, shmseg); 1500 CP(u.shminfo, u32.shminfo32, shmall); 1501 error = copyout(&u32.shminfo32, uap->buf, 1502 sizeof(u32.shminfo32)); 1503 break; 1504 case SHM_INFO: 1505 CP(u.shm_info, u32.shm_info32, used_ids); 1506 CP(u.shm_info, u32.shm_info32, shm_rss); 1507 CP(u.shm_info, u32.shm_info32, shm_tot); 1508 CP(u.shm_info, u32.shm_info32, shm_swp); 1509 CP(u.shm_info, u32.shm_info32, swap_attempts); 1510 CP(u.shm_info, u32.shm_info32, swap_successes); 1511 error = copyout(&u32.shm_info32, uap->buf, 1512 sizeof(u32.shm_info32)); 1513 break; 1514 case SHM_STAT: 1515 case IPC_STAT: 1516 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm, 1517 &u32.shmid_ds32.shm_perm); 1518 if (u.shmid_ds.shm_segsz > INT32_MAX) 1519 u32.shmid_ds32.shm_segsz = INT32_MAX; 1520 else 1521 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1522 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1523 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1524 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1525 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1526 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1527 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1528 error = copyout(&u32.shmid_ds32, uap->buf, 1529 sizeof(u32.shmid_ds32)); 1530 break; 1531 } 1532 1533 done: 1534 if (error) { 1535 /* Invalidate the return value */ 1536 td->td_retval[0] = -1; 1537 } 1538 return (error); 1539 } 1540 #endif 1541 1542 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1543 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1544 1545 #ifndef CP 1546 #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0) 1547 #endif 1548 1549 #ifndef _SYS_SYSPROTO_H_ 1550 struct freebsd7_shmctl_args { 1551 int shmid; 1552 int cmd; 1553 struct shmid_ds_old *buf; 1554 }; 1555 #endif 1556 int 1557 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap) 1558 { 1559 int error = 0; 1560 struct shmid_ds_old old; 1561 struct shmid_ds buf; 1562 size_t bufsz; 1563 1564 /* 1565 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 1566 * Linux binaries. If we see the call come through the FreeBSD ABI, 1567 * return an error back to the user since we do not to support this. 1568 */ 1569 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 1570 uap->cmd == SHM_STAT) 1571 return (EINVAL); 1572 1573 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 1574 if (uap->cmd == IPC_SET) { 1575 if ((error = copyin(uap->buf, &old, sizeof(old)))) 1576 goto done; 1577 ipcperm_old2new(&old.shm_perm, &buf.shm_perm); 1578 CP(old, buf, shm_segsz); 1579 CP(old, buf, shm_lpid); 1580 CP(old, buf, shm_cpid); 1581 CP(old, buf, shm_nattch); 1582 CP(old, buf, shm_atime); 1583 CP(old, buf, shm_dtime); 1584 CP(old, buf, shm_ctime); 1585 } 1586 1587 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 1588 if (error) 1589 goto done; 1590 1591 /* Cases in which we need to copyout */ 1592 switch (uap->cmd) { 1593 case IPC_STAT: 1594 ipcperm_new2old(&buf.shm_perm, &old.shm_perm); 1595 if (buf.shm_segsz > INT_MAX) 1596 old.shm_segsz = INT_MAX; 1597 else 1598 CP(buf, old, shm_segsz); 1599 CP(buf, old, shm_lpid); 1600 CP(buf, old, shm_cpid); 1601 if (buf.shm_nattch > SHRT_MAX) 1602 old.shm_nattch = SHRT_MAX; 1603 else 1604 CP(buf, old, shm_nattch); 1605 CP(buf, old, shm_atime); 1606 CP(buf, old, shm_dtime); 1607 CP(buf, old, shm_ctime); 1608 old.shm_internal = NULL; 1609 error = copyout(&old, uap->buf, sizeof(old)); 1610 break; 1611 } 1612 1613 done: 1614 if (error) { 1615 /* Invalidate the return value */ 1616 td->td_retval[0] = -1; 1617 } 1618 return (error); 1619 } 1620 1621 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || 1622 COMPAT_FREEBSD7 */ 1623 1624 static int 1625 sysvshm_modload(struct module *module, int cmd, void *arg) 1626 { 1627 int error = 0; 1628 1629 switch (cmd) { 1630 case MOD_LOAD: 1631 error = shminit(); 1632 if (error != 0) 1633 shmunload(); 1634 break; 1635 case MOD_UNLOAD: 1636 error = shmunload(); 1637 break; 1638 case MOD_SHUTDOWN: 1639 break; 1640 default: 1641 error = EINVAL; 1642 break; 1643 } 1644 return (error); 1645 } 1646 1647 static moduledata_t sysvshm_mod = { 1648 "sysvshm", 1649 &sysvshm_modload, 1650 NULL 1651 }; 1652 1653 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST); 1654 MODULE_VERSION(sysvshm, 1);
Cache object: 7ed7733e21f12a76565f89e31c524ef4
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