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/sbuf.h> 84 #include <sys/stat.h> 85 #include <sys/syscall.h> 86 #include <sys/syscallsubr.h> 87 #include <sys/sysent.h> 88 #include <sys/sysproto.h> 89 #include <sys/jail.h> 90 91 #include <security/mac/mac_framework.h> 92 93 #include <vm/vm.h> 94 #include <vm/vm_param.h> 95 #include <vm/pmap.h> 96 #include <vm/vm_object.h> 97 #include <vm/vm_map.h> 98 #include <vm/vm_page.h> 99 #include <vm/vm_pager.h> 100 101 FEATURE(sysv_shm, "System V shared memory segments support"); 102 103 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments"); 104 105 static int shmget_allocate_segment(struct thread *td, 106 struct shmget_args *uap, int mode); 107 static int shmget_existing(struct thread *td, struct shmget_args *uap, 108 int mode, int segnum); 109 110 #define SHMSEG_FREE 0x0200 111 #define SHMSEG_REMOVED 0x0400 112 #define SHMSEG_ALLOCATED 0x0800 113 114 static int shm_last_free, shm_nused, shmalloced; 115 vm_size_t shm_committed; 116 static struct shmid_kernel *shmsegs; 117 static unsigned shm_prison_slot; 118 119 struct shmmap_state { 120 vm_offset_t va; 121 int shmid; 122 }; 123 124 static void shm_deallocate_segment(struct shmid_kernel *); 125 static int shm_find_segment_by_key(struct prison *, key_t); 126 static struct shmid_kernel *shm_find_segment(struct prison *, int, bool); 127 static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *); 128 static void shmrealloc(void); 129 static int shminit(void); 130 static int sysvshm_modload(struct module *, int, void *); 131 static int shmunload(void); 132 static void shmexit_myhook(struct vmspace *vm); 133 static void shmfork_myhook(struct proc *p1, struct proc *p2); 134 static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS); 135 static void shm_remove(struct shmid_kernel *, int); 136 static struct prison *shm_find_prison(struct ucred *); 137 static int shm_prison_cansee(struct prison *, struct shmid_kernel *); 138 static int shm_prison_check(void *, void *); 139 static int shm_prison_set(void *, void *); 140 static int shm_prison_get(void *, void *); 141 static int shm_prison_remove(void *, void *); 142 static void shm_prison_cleanup(struct prison *); 143 144 /* 145 * Tuneable values. 146 */ 147 #ifndef SHMMAXPGS 148 #define SHMMAXPGS 131072 /* Note: sysv shared memory is swap backed. */ 149 #endif 150 #ifndef SHMMAX 151 #define SHMMAX (SHMMAXPGS*PAGE_SIZE) 152 #endif 153 #ifndef SHMMIN 154 #define SHMMIN 1 155 #endif 156 #ifndef SHMMNI 157 #define SHMMNI 192 158 #endif 159 #ifndef SHMSEG 160 #define SHMSEG 128 161 #endif 162 #ifndef SHMALL 163 #define SHMALL (SHMMAXPGS) 164 #endif 165 166 struct shminfo shminfo = { 167 .shmmax = SHMMAX, 168 .shmmin = SHMMIN, 169 .shmmni = SHMMNI, 170 .shmseg = SHMSEG, 171 .shmall = SHMALL 172 }; 173 174 static int shm_use_phys; 175 static int shm_allow_removed = 1; 176 177 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RWTUN, &shminfo.shmmax, 0, 178 "Maximum shared memory segment size"); 179 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RWTUN, &shminfo.shmmin, 0, 180 "Minimum shared memory segment size"); 181 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0, 182 "Number of shared memory identifiers"); 183 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0, 184 "Number of segments per process"); 185 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RWTUN, &shminfo.shmall, 0, 186 "Maximum number of pages available for shared memory"); 187 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RWTUN, 188 &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core"); 189 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RWTUN, 190 &shm_allow_removed, 0, 191 "Enable/Disable attachment to attached segments marked for removal"); 192 SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD | 193 CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "", 194 "Current number of shared memory segments allocated"); 195 196 static struct sx sysvshmsx; 197 #define SYSVSHM_LOCK() sx_xlock(&sysvshmsx) 198 #define SYSVSHM_UNLOCK() sx_xunlock(&sysvshmsx) 199 #define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED) 200 201 static int 202 shm_find_segment_by_key(struct prison *pr, key_t key) 203 { 204 int i; 205 206 for (i = 0; i < shmalloced; i++) 207 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) && 208 shmsegs[i].cred != NULL && 209 shmsegs[i].cred->cr_prison == pr && 210 shmsegs[i].u.shm_perm.key == key) 211 return (i); 212 return (-1); 213 } 214 215 /* 216 * Finds segment either by shmid if is_shmid is true, or by segnum if 217 * is_shmid is false. 218 */ 219 static struct shmid_kernel * 220 shm_find_segment(struct prison *rpr, int arg, bool is_shmid) 221 { 222 struct shmid_kernel *shmseg; 223 int segnum; 224 225 segnum = is_shmid ? IPCID_TO_IX(arg) : arg; 226 if (segnum < 0 || segnum >= shmalloced) 227 return (NULL); 228 shmseg = &shmsegs[segnum]; 229 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 230 (!shm_allow_removed && 231 (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) || 232 (is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg)) || 233 shm_prison_cansee(rpr, shmseg) != 0) 234 return (NULL); 235 return (shmseg); 236 } 237 238 static void 239 shm_deallocate_segment(struct shmid_kernel *shmseg) 240 { 241 vm_size_t size; 242 243 SYSVSHM_ASSERT_LOCKED(); 244 245 vm_object_deallocate(shmseg->object); 246 shmseg->object = NULL; 247 size = round_page(shmseg->u.shm_segsz); 248 shm_committed -= btoc(size); 249 shm_nused--; 250 shmseg->u.shm_perm.mode = SHMSEG_FREE; 251 #ifdef MAC 252 mac_sysvshm_cleanup(shmseg); 253 #endif 254 racct_sub_cred(shmseg->cred, RACCT_NSHM, 1); 255 racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size); 256 crfree(shmseg->cred); 257 shmseg->cred = NULL; 258 } 259 260 static int 261 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s) 262 { 263 struct shmid_kernel *shmseg; 264 int segnum, result; 265 vm_size_t size; 266 267 SYSVSHM_ASSERT_LOCKED(); 268 segnum = IPCID_TO_IX(shmmap_s->shmid); 269 KASSERT(segnum >= 0 && segnum < shmalloced, 270 ("segnum %d shmalloced %d", segnum, shmalloced)); 271 272 shmseg = &shmsegs[segnum]; 273 size = round_page(shmseg->u.shm_segsz); 274 result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size); 275 if (result != KERN_SUCCESS) 276 return (EINVAL); 277 shmmap_s->shmid = -1; 278 shmseg->u.shm_dtime = time_second; 279 if ((--shmseg->u.shm_nattch <= 0) && 280 (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) { 281 shm_deallocate_segment(shmseg); 282 shm_last_free = segnum; 283 } 284 return (0); 285 } 286 287 static void 288 shm_remove(struct shmid_kernel *shmseg, int segnum) 289 { 290 291 shmseg->u.shm_perm.key = IPC_PRIVATE; 292 shmseg->u.shm_perm.mode |= SHMSEG_REMOVED; 293 if (shmseg->u.shm_nattch <= 0) { 294 shm_deallocate_segment(shmseg); 295 shm_last_free = segnum; 296 } 297 } 298 299 static struct prison * 300 shm_find_prison(struct ucred *cred) 301 { 302 struct prison *pr, *rpr; 303 304 pr = cred->cr_prison; 305 prison_lock(pr); 306 rpr = osd_jail_get(pr, shm_prison_slot); 307 prison_unlock(pr); 308 return rpr; 309 } 310 311 static int 312 shm_prison_cansee(struct prison *rpr, struct shmid_kernel *shmseg) 313 { 314 315 if (shmseg->cred == NULL || 316 !(rpr == shmseg->cred->cr_prison || 317 prison_ischild(rpr, shmseg->cred->cr_prison))) 318 return (EINVAL); 319 return (0); 320 } 321 322 static int 323 kern_shmdt_locked(struct thread *td, const void *shmaddr) 324 { 325 struct proc *p = td->td_proc; 326 struct shmmap_state *shmmap_s; 327 #ifdef MAC 328 struct shmid_kernel *shmsegptr; 329 int error; 330 #endif 331 int i; 332 333 SYSVSHM_ASSERT_LOCKED(); 334 if (shm_find_prison(td->td_ucred) == NULL) 335 return (ENOSYS); 336 shmmap_s = p->p_vmspace->vm_shm; 337 if (shmmap_s == NULL) 338 return (EINVAL); 339 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 340 if (shmmap_s->shmid != -1 && 341 shmmap_s->va == (vm_offset_t)shmaddr) { 342 break; 343 } 344 } 345 if (i == shminfo.shmseg) 346 return (EINVAL); 347 #ifdef MAC 348 shmsegptr = &shmsegs[IPCID_TO_IX(shmmap_s->shmid)]; 349 error = mac_sysvshm_check_shmdt(td->td_ucred, shmsegptr); 350 if (error != 0) 351 return (error); 352 #endif 353 return (shm_delete_mapping(p->p_vmspace, shmmap_s)); 354 } 355 356 #ifndef _SYS_SYSPROTO_H_ 357 struct shmdt_args { 358 const void *shmaddr; 359 }; 360 #endif 361 int 362 sys_shmdt(struct thread *td, struct shmdt_args *uap) 363 { 364 int error; 365 366 SYSVSHM_LOCK(); 367 error = kern_shmdt_locked(td, uap->shmaddr); 368 SYSVSHM_UNLOCK(); 369 return (error); 370 } 371 372 static int 373 kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr, 374 int shmflg) 375 { 376 struct prison *rpr; 377 struct proc *p = td->td_proc; 378 struct shmid_kernel *shmseg; 379 struct shmmap_state *shmmap_s; 380 vm_offset_t attach_va; 381 vm_prot_t prot; 382 vm_size_t size; 383 int error, i, rv; 384 385 SYSVSHM_ASSERT_LOCKED(); 386 rpr = shm_find_prison(td->td_ucred); 387 if (rpr == NULL) 388 return (ENOSYS); 389 shmmap_s = p->p_vmspace->vm_shm; 390 if (shmmap_s == NULL) { 391 shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state), 392 M_SHM, M_WAITOK); 393 for (i = 0; i < shminfo.shmseg; i++) 394 shmmap_s[i].shmid = -1; 395 KASSERT(p->p_vmspace->vm_shm == NULL, ("raced")); 396 p->p_vmspace->vm_shm = shmmap_s; 397 } 398 shmseg = shm_find_segment(rpr, shmid, true); 399 if (shmseg == NULL) 400 return (EINVAL); 401 error = ipcperm(td, &shmseg->u.shm_perm, 402 (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); 403 if (error != 0) 404 return (error); 405 #ifdef MAC 406 error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg); 407 if (error != 0) 408 return (error); 409 #endif 410 for (i = 0; i < shminfo.shmseg; i++) { 411 if (shmmap_s->shmid == -1) 412 break; 413 shmmap_s++; 414 } 415 if (i >= shminfo.shmseg) 416 return (EMFILE); 417 size = round_page(shmseg->u.shm_segsz); 418 prot = VM_PROT_READ; 419 if ((shmflg & SHM_RDONLY) == 0) 420 prot |= VM_PROT_WRITE; 421 if (shmaddr != NULL) { 422 if ((shmflg & SHM_RND) != 0) 423 attach_va = rounddown2((vm_offset_t)shmaddr, SHMLBA); 424 else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0) 425 attach_va = (vm_offset_t)shmaddr; 426 else 427 return (EINVAL); 428 } else { 429 /* 430 * This is just a hint to vm_map_find() about where to 431 * put it. 432 */ 433 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 434 lim_max(td, RLIMIT_DATA)); 435 } 436 437 vm_object_reference(shmseg->object); 438 rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object, 0, &attach_va, 439 size, 0, shmaddr != NULL ? VMFS_NO_SPACE : VMFS_OPTIMAL_SPACE, 440 prot, prot, MAP_INHERIT_SHARE | MAP_PREFAULT_PARTIAL); 441 if (rv != KERN_SUCCESS) { 442 vm_object_deallocate(shmseg->object); 443 return (ENOMEM); 444 } 445 446 shmmap_s->va = attach_va; 447 shmmap_s->shmid = shmid; 448 shmseg->u.shm_lpid = p->p_pid; 449 shmseg->u.shm_atime = time_second; 450 shmseg->u.shm_nattch++; 451 td->td_retval[0] = attach_va; 452 return (error); 453 } 454 455 int 456 kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg) 457 { 458 int error; 459 460 SYSVSHM_LOCK(); 461 error = kern_shmat_locked(td, shmid, shmaddr, shmflg); 462 SYSVSHM_UNLOCK(); 463 return (error); 464 } 465 466 #ifndef _SYS_SYSPROTO_H_ 467 struct shmat_args { 468 int shmid; 469 const void *shmaddr; 470 int shmflg; 471 }; 472 #endif 473 int 474 sys_shmat(struct thread *td, struct shmat_args *uap) 475 { 476 477 return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg)); 478 } 479 480 static int 481 kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf, 482 size_t *bufsz) 483 { 484 struct prison *rpr; 485 struct shmid_kernel *shmseg; 486 struct shmid_ds *shmidp; 487 struct shm_info shm_info; 488 int error; 489 490 SYSVSHM_ASSERT_LOCKED(); 491 492 rpr = shm_find_prison(td->td_ucred); 493 if (rpr == NULL) 494 return (ENOSYS); 495 496 switch (cmd) { 497 /* 498 * It is possible that kern_shmctl is being called from the Linux ABI 499 * layer, in which case, we will need to implement IPC_INFO. It should 500 * be noted that other shmctl calls will be funneled through here for 501 * Linix binaries as well. 502 * 503 * NB: The Linux ABI layer will convert this data to structure(s) more 504 * consistent with the Linux ABI. 505 */ 506 case IPC_INFO: 507 memcpy(buf, &shminfo, sizeof(shminfo)); 508 if (bufsz) 509 *bufsz = sizeof(shminfo); 510 td->td_retval[0] = shmalloced; 511 return (0); 512 case SHM_INFO: { 513 shm_info.used_ids = shm_nused; 514 shm_info.shm_rss = 0; /*XXX where to get from ? */ 515 shm_info.shm_tot = 0; /*XXX where to get from ? */ 516 shm_info.shm_swp = 0; /*XXX where to get from ? */ 517 shm_info.swap_attempts = 0; /*XXX where to get from ? */ 518 shm_info.swap_successes = 0; /*XXX where to get from ? */ 519 memcpy(buf, &shm_info, sizeof(shm_info)); 520 if (bufsz != NULL) 521 *bufsz = sizeof(shm_info); 522 td->td_retval[0] = shmalloced; 523 return (0); 524 } 525 } 526 shmseg = shm_find_segment(rpr, shmid, cmd != SHM_STAT); 527 if (shmseg == NULL) 528 return (EINVAL); 529 #ifdef MAC 530 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd); 531 if (error != 0) 532 return (error); 533 #endif 534 switch (cmd) { 535 case SHM_STAT: 536 case IPC_STAT: 537 shmidp = (struct shmid_ds *)buf; 538 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 539 if (error != 0) 540 return (error); 541 memcpy(shmidp, &shmseg->u, sizeof(struct shmid_ds)); 542 if (td->td_ucred->cr_prison != shmseg->cred->cr_prison) 543 shmidp->shm_perm.key = IPC_PRIVATE; 544 if (bufsz != NULL) 545 *bufsz = sizeof(struct shmid_ds); 546 if (cmd == SHM_STAT) { 547 td->td_retval[0] = IXSEQ_TO_IPCID(shmid, 548 shmseg->u.shm_perm); 549 } 550 break; 551 case IPC_SET: 552 shmidp = (struct shmid_ds *)buf; 553 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); 554 if (error != 0) 555 return (error); 556 shmseg->u.shm_perm.uid = shmidp->shm_perm.uid; 557 shmseg->u.shm_perm.gid = shmidp->shm_perm.gid; 558 shmseg->u.shm_perm.mode = 559 (shmseg->u.shm_perm.mode & ~ACCESSPERMS) | 560 (shmidp->shm_perm.mode & ACCESSPERMS); 561 shmseg->u.shm_ctime = time_second; 562 break; 563 case IPC_RMID: 564 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); 565 if (error != 0) 566 return (error); 567 shm_remove(shmseg, IPCID_TO_IX(shmid)); 568 break; 569 #if 0 570 case SHM_LOCK: 571 case SHM_UNLOCK: 572 #endif 573 default: 574 error = EINVAL; 575 break; 576 } 577 return (error); 578 } 579 580 int 581 kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz) 582 { 583 int error; 584 585 SYSVSHM_LOCK(); 586 error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz); 587 SYSVSHM_UNLOCK(); 588 return (error); 589 } 590 591 592 #ifndef _SYS_SYSPROTO_H_ 593 struct shmctl_args { 594 int shmid; 595 int cmd; 596 struct shmid_ds *buf; 597 }; 598 #endif 599 int 600 sys_shmctl(struct thread *td, struct shmctl_args *uap) 601 { 602 int error; 603 struct shmid_ds buf; 604 size_t bufsz; 605 606 /* 607 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 608 * Linux binaries. If we see the call come through the FreeBSD ABI, 609 * return an error back to the user since we do not to support this. 610 */ 611 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 612 uap->cmd == SHM_STAT) 613 return (EINVAL); 614 615 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 616 if (uap->cmd == IPC_SET) { 617 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds)))) 618 goto done; 619 } 620 621 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 622 if (error) 623 goto done; 624 625 /* Cases in which we need to copyout */ 626 switch (uap->cmd) { 627 case IPC_STAT: 628 error = copyout(&buf, uap->buf, bufsz); 629 break; 630 } 631 632 done: 633 if (error) { 634 /* Invalidate the return value */ 635 td->td_retval[0] = -1; 636 } 637 return (error); 638 } 639 640 641 static int 642 shmget_existing(struct thread *td, struct shmget_args *uap, int mode, 643 int segnum) 644 { 645 struct shmid_kernel *shmseg; 646 #ifdef MAC 647 int error; 648 #endif 649 650 SYSVSHM_ASSERT_LOCKED(); 651 KASSERT(segnum >= 0 && segnum < shmalloced, 652 ("segnum %d shmalloced %d", segnum, shmalloced)); 653 shmseg = &shmsegs[segnum]; 654 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) 655 return (EEXIST); 656 #ifdef MAC 657 error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg); 658 if (error != 0) 659 return (error); 660 #endif 661 if (uap->size != 0 && uap->size > shmseg->u.shm_segsz) 662 return (EINVAL); 663 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 664 return (0); 665 } 666 667 static int 668 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode) 669 { 670 struct ucred *cred = td->td_ucred; 671 struct shmid_kernel *shmseg; 672 vm_object_t shm_object; 673 int i, segnum; 674 size_t size; 675 676 SYSVSHM_ASSERT_LOCKED(); 677 678 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) 679 return (EINVAL); 680 if (shm_nused >= shminfo.shmmni) /* Any shmids left? */ 681 return (ENOSPC); 682 size = round_page(uap->size); 683 if (shm_committed + btoc(size) > shminfo.shmall) 684 return (ENOMEM); 685 if (shm_last_free < 0) { 686 shmrealloc(); /* Maybe expand the shmsegs[] array. */ 687 for (i = 0; i < shmalloced; i++) 688 if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE) 689 break; 690 if (i == shmalloced) 691 return (ENOSPC); 692 segnum = i; 693 } else { 694 segnum = shm_last_free; 695 shm_last_free = -1; 696 } 697 KASSERT(segnum >= 0 && segnum < shmalloced, 698 ("segnum %d shmalloced %d", segnum, shmalloced)); 699 shmseg = &shmsegs[segnum]; 700 #ifdef RACCT 701 if (racct_enable) { 702 PROC_LOCK(td->td_proc); 703 if (racct_add(td->td_proc, RACCT_NSHM, 1)) { 704 PROC_UNLOCK(td->td_proc); 705 return (ENOSPC); 706 } 707 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) { 708 racct_sub(td->td_proc, RACCT_NSHM, 1); 709 PROC_UNLOCK(td->td_proc); 710 return (ENOMEM); 711 } 712 PROC_UNLOCK(td->td_proc); 713 } 714 #endif 715 716 /* 717 * We make sure that we have allocated a pager before we need 718 * to. 719 */ 720 shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP, 721 0, size, VM_PROT_DEFAULT, 0, cred); 722 if (shm_object == NULL) { 723 #ifdef RACCT 724 if (racct_enable) { 725 PROC_LOCK(td->td_proc); 726 racct_sub(td->td_proc, RACCT_NSHM, 1); 727 racct_sub(td->td_proc, RACCT_SHMSIZE, size); 728 PROC_UNLOCK(td->td_proc); 729 } 730 #endif 731 return (ENOMEM); 732 } 733 shm_object->pg_color = 0; 734 VM_OBJECT_WLOCK(shm_object); 735 vm_object_clear_flag(shm_object, OBJ_ONEMAPPING); 736 vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT); 737 VM_OBJECT_WUNLOCK(shm_object); 738 739 shmseg->object = shm_object; 740 shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid; 741 shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid; 742 shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; 743 shmseg->u.shm_perm.key = uap->key; 744 shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff; 745 shmseg->cred = crhold(cred); 746 shmseg->u.shm_segsz = uap->size; 747 shmseg->u.shm_cpid = td->td_proc->p_pid; 748 shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0; 749 shmseg->u.shm_atime = shmseg->u.shm_dtime = 0; 750 #ifdef MAC 751 mac_sysvshm_create(cred, shmseg); 752 #endif 753 shmseg->u.shm_ctime = time_second; 754 shm_committed += btoc(size); 755 shm_nused++; 756 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 757 758 return (0); 759 } 760 761 #ifndef _SYS_SYSPROTO_H_ 762 struct shmget_args { 763 key_t key; 764 size_t size; 765 int shmflg; 766 }; 767 #endif 768 int 769 sys_shmget(struct thread *td, struct shmget_args *uap) 770 { 771 int segnum, mode; 772 int error; 773 774 if (shm_find_prison(td->td_ucred) == NULL) 775 return (ENOSYS); 776 mode = uap->shmflg & ACCESSPERMS; 777 SYSVSHM_LOCK(); 778 if (uap->key == IPC_PRIVATE) { 779 error = shmget_allocate_segment(td, uap, mode); 780 } else { 781 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison, 782 uap->key); 783 if (segnum >= 0) 784 error = shmget_existing(td, uap, mode, segnum); 785 else if ((uap->shmflg & IPC_CREAT) == 0) 786 error = ENOENT; 787 else 788 error = shmget_allocate_segment(td, uap, mode); 789 } 790 SYSVSHM_UNLOCK(); 791 return (error); 792 } 793 794 static void 795 shmfork_myhook(struct proc *p1, struct proc *p2) 796 { 797 struct shmmap_state *shmmap_s; 798 size_t size; 799 int i; 800 801 SYSVSHM_LOCK(); 802 size = shminfo.shmseg * sizeof(struct shmmap_state); 803 shmmap_s = malloc(size, M_SHM, M_WAITOK); 804 bcopy(p1->p_vmspace->vm_shm, shmmap_s, size); 805 p2->p_vmspace->vm_shm = shmmap_s; 806 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 807 if (shmmap_s->shmid != -1) { 808 KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 && 809 IPCID_TO_IX(shmmap_s->shmid) < shmalloced, 810 ("segnum %d shmalloced %d", 811 IPCID_TO_IX(shmmap_s->shmid), shmalloced)); 812 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++; 813 } 814 } 815 SYSVSHM_UNLOCK(); 816 } 817 818 static void 819 shmexit_myhook(struct vmspace *vm) 820 { 821 struct shmmap_state *base, *shm; 822 int i; 823 824 base = vm->vm_shm; 825 if (base != NULL) { 826 vm->vm_shm = NULL; 827 SYSVSHM_LOCK(); 828 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) { 829 if (shm->shmid != -1) 830 shm_delete_mapping(vm, shm); 831 } 832 SYSVSHM_UNLOCK(); 833 free(base, M_SHM); 834 } 835 } 836 837 static void 838 shmrealloc(void) 839 { 840 struct shmid_kernel *newsegs; 841 int i; 842 843 SYSVSHM_ASSERT_LOCKED(); 844 845 if (shmalloced >= shminfo.shmmni) 846 return; 847 848 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK); 849 for (i = 0; i < shmalloced; i++) 850 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 851 for (; i < shminfo.shmmni; i++) { 852 newsegs[i].u.shm_perm.mode = SHMSEG_FREE; 853 newsegs[i].u.shm_perm.seq = 0; 854 #ifdef MAC 855 mac_sysvshm_init(&newsegs[i]); 856 #endif 857 } 858 free(shmsegs, M_SHM); 859 shmsegs = newsegs; 860 shmalloced = shminfo.shmmni; 861 } 862 863 static struct syscall_helper_data shm_syscalls[] = { 864 SYSCALL_INIT_HELPER(shmat), 865 SYSCALL_INIT_HELPER(shmctl), 866 SYSCALL_INIT_HELPER(shmdt), 867 SYSCALL_INIT_HELPER(shmget), 868 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 869 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 870 SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl), 871 #endif 872 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 873 SYSCALL_INIT_HELPER(shmsys), 874 #endif 875 SYSCALL_INIT_LAST 876 }; 877 878 #ifdef COMPAT_FREEBSD32 879 #include <compat/freebsd32/freebsd32.h> 880 #include <compat/freebsd32/freebsd32_ipc.h> 881 #include <compat/freebsd32/freebsd32_proto.h> 882 #include <compat/freebsd32/freebsd32_signal.h> 883 #include <compat/freebsd32/freebsd32_syscall.h> 884 #include <compat/freebsd32/freebsd32_util.h> 885 886 static struct syscall_helper_data shm32_syscalls[] = { 887 SYSCALL32_INIT_HELPER_COMPAT(shmat), 888 SYSCALL32_INIT_HELPER_COMPAT(shmdt), 889 SYSCALL32_INIT_HELPER_COMPAT(shmget), 890 SYSCALL32_INIT_HELPER(freebsd32_shmsys), 891 SYSCALL32_INIT_HELPER(freebsd32_shmctl), 892 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 893 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 894 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl), 895 #endif 896 SYSCALL_INIT_LAST 897 }; 898 #endif 899 900 static int 901 shminit(void) 902 { 903 struct prison *pr; 904 void *rsv; 905 int i, error; 906 osd_method_t methods[PR_MAXMETHOD] = { 907 [PR_METHOD_CHECK] = shm_prison_check, 908 [PR_METHOD_SET] = shm_prison_set, 909 [PR_METHOD_GET] = shm_prison_get, 910 [PR_METHOD_REMOVE] = shm_prison_remove, 911 }; 912 913 #ifndef BURN_BRIDGES 914 if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0) 915 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n"); 916 #endif 917 if (shminfo.shmmax == SHMMAX) { 918 /* Initialize shmmax dealing with possible overflow. */ 919 for (i = PAGE_SIZE; i != 0; i--) { 920 shminfo.shmmax = shminfo.shmall * i; 921 if ((shminfo.shmmax / shminfo.shmall) == (u_long)i) 922 break; 923 } 924 } 925 shmalloced = shminfo.shmmni; 926 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK); 927 for (i = 0; i < shmalloced; i++) { 928 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; 929 shmsegs[i].u.shm_perm.seq = 0; 930 #ifdef MAC 931 mac_sysvshm_init(&shmsegs[i]); 932 #endif 933 } 934 shm_last_free = 0; 935 shm_nused = 0; 936 shm_committed = 0; 937 sx_init(&sysvshmsx, "sysvshmsx"); 938 shmexit_hook = &shmexit_myhook; 939 shmfork_hook = &shmfork_myhook; 940 941 /* Set current prisons according to their allow.sysvipc. */ 942 shm_prison_slot = osd_jail_register(NULL, methods); 943 rsv = osd_reserve(shm_prison_slot); 944 prison_lock(&prison0); 945 (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0); 946 prison_unlock(&prison0); 947 rsv = NULL; 948 sx_slock(&allprison_lock); 949 TAILQ_FOREACH(pr, &allprison, pr_list) { 950 if (rsv == NULL) 951 rsv = osd_reserve(shm_prison_slot); 952 prison_lock(pr); 953 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) { 954 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 955 &prison0); 956 rsv = NULL; 957 } 958 prison_unlock(pr); 959 } 960 if (rsv != NULL) 961 osd_free_reserved(rsv); 962 sx_sunlock(&allprison_lock); 963 964 error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD); 965 if (error != 0) 966 return (error); 967 #ifdef COMPAT_FREEBSD32 968 error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD); 969 if (error != 0) 970 return (error); 971 #endif 972 return (0); 973 } 974 975 static int 976 shmunload(void) 977 { 978 int i; 979 980 if (shm_nused > 0) 981 return (EBUSY); 982 983 #ifdef COMPAT_FREEBSD32 984 syscall32_helper_unregister(shm32_syscalls); 985 #endif 986 syscall_helper_unregister(shm_syscalls); 987 if (shm_prison_slot != 0) 988 osd_jail_deregister(shm_prison_slot); 989 990 for (i = 0; i < shmalloced; i++) { 991 #ifdef MAC 992 mac_sysvshm_destroy(&shmsegs[i]); 993 #endif 994 /* 995 * Objects might be still mapped into the processes 996 * address spaces. Actual free would happen on the 997 * last mapping destruction. 998 */ 999 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE) 1000 vm_object_deallocate(shmsegs[i].object); 1001 } 1002 free(shmsegs, M_SHM); 1003 shmexit_hook = NULL; 1004 shmfork_hook = NULL; 1005 sx_destroy(&sysvshmsx); 1006 return (0); 1007 } 1008 1009 static int 1010 sysctl_shmsegs(SYSCTL_HANDLER_ARGS) 1011 { 1012 struct prison *rpr; 1013 struct sbuf sb; 1014 struct shmid_kernel tmp, empty; 1015 struct shmid_kernel *shmseg; 1016 int error, i; 1017 1018 SYSVSHM_LOCK(); 1019 1020 error = sysctl_wire_old_buffer(req, 0); 1021 if (error != 0) 1022 goto done; 1023 rpr = shm_find_prison(req->td->td_ucred); 1024 sbuf_new_for_sysctl(&sb, NULL, shmalloced * sizeof(shmsegs[0]), req); 1025 1026 bzero(&empty, sizeof(empty)); 1027 empty.u.shm_perm.mode = SHMSEG_FREE; 1028 for (i = 0; i < shmalloced; i++) { 1029 shmseg = &shmsegs[i]; 1030 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 1031 rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) { 1032 shmseg = ∅ 1033 } else if (req->td->td_ucred->cr_prison != 1034 shmseg->cred->cr_prison) { 1035 bcopy(shmseg, &tmp, sizeof(tmp)); 1036 shmseg = &tmp; 1037 shmseg->u.shm_perm.key = IPC_PRIVATE; 1038 } 1039 1040 sbuf_bcat(&sb, shmseg, sizeof(*shmseg)); 1041 } 1042 error = sbuf_finish(&sb); 1043 sbuf_delete(&sb); 1044 1045 done: 1046 SYSVSHM_UNLOCK(); 1047 return (error); 1048 } 1049 1050 static int 1051 shm_prison_check(void *obj, void *data) 1052 { 1053 struct prison *pr = obj; 1054 struct prison *prpr; 1055 struct vfsoptlist *opts = data; 1056 int error, jsys; 1057 1058 /* 1059 * sysvshm is a jailsys integer. 1060 * It must be "disable" if the parent jail is disabled. 1061 */ 1062 error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1063 if (error != ENOENT) { 1064 if (error != 0) 1065 return (error); 1066 switch (jsys) { 1067 case JAIL_SYS_DISABLE: 1068 break; 1069 case JAIL_SYS_NEW: 1070 case JAIL_SYS_INHERIT: 1071 prison_lock(pr->pr_parent); 1072 prpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1073 prison_unlock(pr->pr_parent); 1074 if (prpr == NULL) 1075 return (EPERM); 1076 break; 1077 default: 1078 return (EINVAL); 1079 } 1080 } 1081 1082 return (0); 1083 } 1084 1085 static int 1086 shm_prison_set(void *obj, void *data) 1087 { 1088 struct prison *pr = obj; 1089 struct prison *tpr, *orpr, *nrpr, *trpr; 1090 struct vfsoptlist *opts = data; 1091 void *rsv; 1092 int jsys, descend; 1093 1094 /* 1095 * sysvshm controls which jail is the root of the associated segments 1096 * (this jail or same as the parent), or if the feature is available 1097 * at all. 1098 */ 1099 if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT) 1100 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0) 1101 ? JAIL_SYS_INHERIT 1102 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0) 1103 ? JAIL_SYS_DISABLE 1104 : -1; 1105 if (jsys == JAIL_SYS_DISABLE) { 1106 prison_lock(pr); 1107 orpr = osd_jail_get(pr, shm_prison_slot); 1108 if (orpr != NULL) 1109 osd_jail_del(pr, shm_prison_slot); 1110 prison_unlock(pr); 1111 if (orpr != NULL) { 1112 if (orpr == pr) 1113 shm_prison_cleanup(pr); 1114 /* Disable all child jails as well. */ 1115 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1116 prison_lock(tpr); 1117 trpr = osd_jail_get(tpr, shm_prison_slot); 1118 if (trpr != NULL) { 1119 osd_jail_del(tpr, shm_prison_slot); 1120 prison_unlock(tpr); 1121 if (trpr == tpr) 1122 shm_prison_cleanup(tpr); 1123 } else { 1124 prison_unlock(tpr); 1125 descend = 0; 1126 } 1127 } 1128 } 1129 } else if (jsys != -1) { 1130 if (jsys == JAIL_SYS_NEW) 1131 nrpr = pr; 1132 else { 1133 prison_lock(pr->pr_parent); 1134 nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1135 prison_unlock(pr->pr_parent); 1136 } 1137 rsv = osd_reserve(shm_prison_slot); 1138 prison_lock(pr); 1139 orpr = osd_jail_get(pr, shm_prison_slot); 1140 if (orpr != nrpr) 1141 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 1142 nrpr); 1143 else 1144 osd_free_reserved(rsv); 1145 prison_unlock(pr); 1146 if (orpr != nrpr) { 1147 if (orpr == pr) 1148 shm_prison_cleanup(pr); 1149 if (orpr != NULL) { 1150 /* Change child jails matching the old root, */ 1151 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1152 prison_lock(tpr); 1153 trpr = osd_jail_get(tpr, 1154 shm_prison_slot); 1155 if (trpr == orpr) { 1156 (void)osd_jail_set(tpr, 1157 shm_prison_slot, nrpr); 1158 prison_unlock(tpr); 1159 if (trpr == tpr) 1160 shm_prison_cleanup(tpr); 1161 } else { 1162 prison_unlock(tpr); 1163 descend = 0; 1164 } 1165 } 1166 } 1167 } 1168 } 1169 1170 return (0); 1171 } 1172 1173 static int 1174 shm_prison_get(void *obj, void *data) 1175 { 1176 struct prison *pr = obj; 1177 struct prison *rpr; 1178 struct vfsoptlist *opts = data; 1179 int error, jsys; 1180 1181 /* Set sysvshm based on the jail's root prison. */ 1182 prison_lock(pr); 1183 rpr = osd_jail_get(pr, shm_prison_slot); 1184 prison_unlock(pr); 1185 jsys = rpr == NULL ? JAIL_SYS_DISABLE 1186 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT; 1187 error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1188 if (error == ENOENT) 1189 error = 0; 1190 return (error); 1191 } 1192 1193 static int 1194 shm_prison_remove(void *obj, void *data __unused) 1195 { 1196 struct prison *pr = obj; 1197 struct prison *rpr; 1198 1199 SYSVSHM_LOCK(); 1200 prison_lock(pr); 1201 rpr = osd_jail_get(pr, shm_prison_slot); 1202 prison_unlock(pr); 1203 if (rpr == pr) 1204 shm_prison_cleanup(pr); 1205 SYSVSHM_UNLOCK(); 1206 return (0); 1207 } 1208 1209 static void 1210 shm_prison_cleanup(struct prison *pr) 1211 { 1212 struct shmid_kernel *shmseg; 1213 int i; 1214 1215 /* Remove any segments that belong to this jail. */ 1216 for (i = 0; i < shmalloced; i++) { 1217 shmseg = &shmsegs[i]; 1218 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) && 1219 shmseg->cred != NULL && shmseg->cred->cr_prison == pr) { 1220 shm_remove(shmseg, i); 1221 } 1222 } 1223 } 1224 1225 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory"); 1226 1227 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 1228 struct oshmid_ds { 1229 struct ipc_perm_old shm_perm; /* operation perms */ 1230 int shm_segsz; /* size of segment (bytes) */ 1231 u_short shm_cpid; /* pid, creator */ 1232 u_short shm_lpid; /* pid, last operation */ 1233 short shm_nattch; /* no. of current attaches */ 1234 time_t shm_atime; /* last attach time */ 1235 time_t shm_dtime; /* last detach time */ 1236 time_t shm_ctime; /* last change time */ 1237 void *shm_handle; /* internal handle for shm segment */ 1238 }; 1239 1240 struct oshmctl_args { 1241 int shmid; 1242 int cmd; 1243 struct oshmid_ds *ubuf; 1244 }; 1245 1246 static int 1247 oshmctl(struct thread *td, struct oshmctl_args *uap) 1248 { 1249 #ifdef COMPAT_43 1250 int error = 0; 1251 struct prison *rpr; 1252 struct shmid_kernel *shmseg; 1253 struct oshmid_ds outbuf; 1254 1255 rpr = shm_find_prison(td->td_ucred); 1256 if (rpr == NULL) 1257 return (ENOSYS); 1258 if (uap->cmd != IPC_STAT) { 1259 return (freebsd7_shmctl(td, 1260 (struct freebsd7_shmctl_args *)uap)); 1261 } 1262 SYSVSHM_LOCK(); 1263 shmseg = shm_find_segment(rpr, uap->shmid, true); 1264 if (shmseg == NULL) { 1265 SYSVSHM_UNLOCK(); 1266 return (EINVAL); 1267 } 1268 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 1269 if (error != 0) { 1270 SYSVSHM_UNLOCK(); 1271 return (error); 1272 } 1273 #ifdef MAC 1274 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd); 1275 if (error != 0) { 1276 SYSVSHM_UNLOCK(); 1277 return (error); 1278 } 1279 #endif 1280 ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm); 1281 outbuf.shm_segsz = shmseg->u.shm_segsz; 1282 outbuf.shm_cpid = shmseg->u.shm_cpid; 1283 outbuf.shm_lpid = shmseg->u.shm_lpid; 1284 outbuf.shm_nattch = shmseg->u.shm_nattch; 1285 outbuf.shm_atime = shmseg->u.shm_atime; 1286 outbuf.shm_dtime = shmseg->u.shm_dtime; 1287 outbuf.shm_ctime = shmseg->u.shm_ctime; 1288 outbuf.shm_handle = shmseg->object; 1289 SYSVSHM_UNLOCK(); 1290 return (copyout(&outbuf, uap->ubuf, sizeof(outbuf))); 1291 #else 1292 return (EINVAL); 1293 #endif 1294 } 1295 1296 /* XXX casting to (sy_call_t *) is bogus, as usual. */ 1297 static sy_call_t *shmcalls[] = { 1298 (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl, 1299 (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget, 1300 (sy_call_t *)freebsd7_shmctl 1301 }; 1302 1303 #ifndef _SYS_SYSPROTO_H_ 1304 /* XXX actually varargs. */ 1305 struct shmsys_args { 1306 int which; 1307 int a2; 1308 int a3; 1309 int a4; 1310 }; 1311 #endif 1312 int 1313 sys_shmsys(struct thread *td, struct shmsys_args *uap) 1314 { 1315 1316 if (uap->which < 0 || uap->which >= nitems(shmcalls)) 1317 return (EINVAL); 1318 return ((*shmcalls[uap->which])(td, &uap->a2)); 1319 } 1320 1321 #endif /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */ 1322 1323 #ifdef COMPAT_FREEBSD32 1324 1325 int 1326 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap) 1327 { 1328 1329 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1330 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1331 switch (uap->which) { 1332 case 0: { /* shmat */ 1333 struct shmat_args ap; 1334 1335 ap.shmid = uap->a2; 1336 ap.shmaddr = PTRIN(uap->a3); 1337 ap.shmflg = uap->a4; 1338 return (sysent[SYS_shmat].sy_call(td, &ap)); 1339 } 1340 case 2: { /* shmdt */ 1341 struct shmdt_args ap; 1342 1343 ap.shmaddr = PTRIN(uap->a2); 1344 return (sysent[SYS_shmdt].sy_call(td, &ap)); 1345 } 1346 case 3: { /* shmget */ 1347 struct shmget_args ap; 1348 1349 ap.key = uap->a2; 1350 ap.size = uap->a3; 1351 ap.shmflg = uap->a4; 1352 return (sysent[SYS_shmget].sy_call(td, &ap)); 1353 } 1354 case 4: { /* shmctl */ 1355 struct freebsd7_freebsd32_shmctl_args ap; 1356 1357 ap.shmid = uap->a2; 1358 ap.cmd = uap->a3; 1359 ap.buf = PTRIN(uap->a4); 1360 return (freebsd7_freebsd32_shmctl(td, &ap)); 1361 } 1362 case 1: /* oshmctl */ 1363 default: 1364 return (EINVAL); 1365 } 1366 #else 1367 return (nosys(td, NULL)); 1368 #endif 1369 } 1370 1371 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1372 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1373 int 1374 freebsd7_freebsd32_shmctl(struct thread *td, 1375 struct freebsd7_freebsd32_shmctl_args *uap) 1376 { 1377 int error; 1378 union { 1379 struct shmid_ds shmid_ds; 1380 struct shm_info shm_info; 1381 struct shminfo shminfo; 1382 } u; 1383 union { 1384 struct shmid_ds32_old shmid_ds32; 1385 struct shm_info32 shm_info32; 1386 struct shminfo32 shminfo32; 1387 } u32; 1388 size_t sz; 1389 1390 if (uap->cmd == IPC_SET) { 1391 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1392 sizeof(u32.shmid_ds32)))) 1393 goto done; 1394 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm, 1395 &u.shmid_ds.shm_perm); 1396 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1397 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1398 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1399 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1400 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1401 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1402 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1403 } 1404 1405 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1406 if (error) 1407 goto done; 1408 1409 /* Cases in which we need to copyout */ 1410 switch (uap->cmd) { 1411 case IPC_INFO: 1412 CP(u.shminfo, u32.shminfo32, shmmax); 1413 CP(u.shminfo, u32.shminfo32, shmmin); 1414 CP(u.shminfo, u32.shminfo32, shmmni); 1415 CP(u.shminfo, u32.shminfo32, shmseg); 1416 CP(u.shminfo, u32.shminfo32, shmall); 1417 error = copyout(&u32.shminfo32, uap->buf, 1418 sizeof(u32.shminfo32)); 1419 break; 1420 case SHM_INFO: 1421 CP(u.shm_info, u32.shm_info32, used_ids); 1422 CP(u.shm_info, u32.shm_info32, shm_rss); 1423 CP(u.shm_info, u32.shm_info32, shm_tot); 1424 CP(u.shm_info, u32.shm_info32, shm_swp); 1425 CP(u.shm_info, u32.shm_info32, swap_attempts); 1426 CP(u.shm_info, u32.shm_info32, swap_successes); 1427 error = copyout(&u32.shm_info32, uap->buf, 1428 sizeof(u32.shm_info32)); 1429 break; 1430 case SHM_STAT: 1431 case IPC_STAT: 1432 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm, 1433 &u32.shmid_ds32.shm_perm); 1434 if (u.shmid_ds.shm_segsz > INT32_MAX) 1435 u32.shmid_ds32.shm_segsz = INT32_MAX; 1436 else 1437 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1438 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1439 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1440 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1441 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1442 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1443 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1444 u32.shmid_ds32.shm_internal = 0; 1445 error = copyout(&u32.shmid_ds32, uap->buf, 1446 sizeof(u32.shmid_ds32)); 1447 break; 1448 } 1449 1450 done: 1451 if (error) { 1452 /* Invalidate the return value */ 1453 td->td_retval[0] = -1; 1454 } 1455 return (error); 1456 } 1457 #endif 1458 1459 int 1460 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap) 1461 { 1462 int error; 1463 union { 1464 struct shmid_ds shmid_ds; 1465 struct shm_info shm_info; 1466 struct shminfo shminfo; 1467 } u; 1468 union { 1469 struct shmid_ds32 shmid_ds32; 1470 struct shm_info32 shm_info32; 1471 struct shminfo32 shminfo32; 1472 } u32; 1473 size_t sz; 1474 1475 if (uap->cmd == IPC_SET) { 1476 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1477 sizeof(u32.shmid_ds32)))) 1478 goto done; 1479 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm, 1480 &u.shmid_ds.shm_perm); 1481 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1482 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1483 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1484 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1485 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1486 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1487 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1488 } 1489 1490 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1491 if (error) 1492 goto done; 1493 1494 /* Cases in which we need to copyout */ 1495 switch (uap->cmd) { 1496 case IPC_INFO: 1497 CP(u.shminfo, u32.shminfo32, shmmax); 1498 CP(u.shminfo, u32.shminfo32, shmmin); 1499 CP(u.shminfo, u32.shminfo32, shmmni); 1500 CP(u.shminfo, u32.shminfo32, shmseg); 1501 CP(u.shminfo, u32.shminfo32, shmall); 1502 error = copyout(&u32.shminfo32, uap->buf, 1503 sizeof(u32.shminfo32)); 1504 break; 1505 case SHM_INFO: 1506 CP(u.shm_info, u32.shm_info32, used_ids); 1507 CP(u.shm_info, u32.shm_info32, shm_rss); 1508 CP(u.shm_info, u32.shm_info32, shm_tot); 1509 CP(u.shm_info, u32.shm_info32, shm_swp); 1510 CP(u.shm_info, u32.shm_info32, swap_attempts); 1511 CP(u.shm_info, u32.shm_info32, swap_successes); 1512 error = copyout(&u32.shm_info32, uap->buf, 1513 sizeof(u32.shm_info32)); 1514 break; 1515 case SHM_STAT: 1516 case IPC_STAT: 1517 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm, 1518 &u32.shmid_ds32.shm_perm); 1519 if (u.shmid_ds.shm_segsz > INT32_MAX) 1520 u32.shmid_ds32.shm_segsz = INT32_MAX; 1521 else 1522 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1523 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1524 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1525 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1526 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1527 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1528 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1529 error = copyout(&u32.shmid_ds32, uap->buf, 1530 sizeof(u32.shmid_ds32)); 1531 break; 1532 } 1533 1534 done: 1535 if (error) { 1536 /* Invalidate the return value */ 1537 td->td_retval[0] = -1; 1538 } 1539 return (error); 1540 } 1541 #endif 1542 1543 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1544 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1545 1546 #ifndef CP 1547 #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0) 1548 #endif 1549 1550 #ifndef _SYS_SYSPROTO_H_ 1551 struct freebsd7_shmctl_args { 1552 int shmid; 1553 int cmd; 1554 struct shmid_ds_old *buf; 1555 }; 1556 #endif 1557 int 1558 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap) 1559 { 1560 int error; 1561 struct shmid_ds_old old; 1562 struct shmid_ds buf; 1563 size_t bufsz; 1564 1565 /* 1566 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 1567 * Linux binaries. If we see the call come through the FreeBSD ABI, 1568 * return an error back to the user since we do not to support this. 1569 */ 1570 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 1571 uap->cmd == SHM_STAT) 1572 return (EINVAL); 1573 1574 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 1575 if (uap->cmd == IPC_SET) { 1576 if ((error = copyin(uap->buf, &old, sizeof(old)))) 1577 goto done; 1578 ipcperm_old2new(&old.shm_perm, &buf.shm_perm); 1579 CP(old, buf, shm_segsz); 1580 CP(old, buf, shm_lpid); 1581 CP(old, buf, shm_cpid); 1582 CP(old, buf, shm_nattch); 1583 CP(old, buf, shm_atime); 1584 CP(old, buf, shm_dtime); 1585 CP(old, buf, shm_ctime); 1586 } 1587 1588 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 1589 if (error) 1590 goto done; 1591 1592 /* Cases in which we need to copyout */ 1593 switch (uap->cmd) { 1594 case IPC_STAT: 1595 ipcperm_new2old(&buf.shm_perm, &old.shm_perm); 1596 if (buf.shm_segsz > INT_MAX) 1597 old.shm_segsz = INT_MAX; 1598 else 1599 CP(buf, old, shm_segsz); 1600 CP(buf, old, shm_lpid); 1601 CP(buf, old, shm_cpid); 1602 if (buf.shm_nattch > SHRT_MAX) 1603 old.shm_nattch = SHRT_MAX; 1604 else 1605 CP(buf, old, shm_nattch); 1606 CP(buf, old, shm_atime); 1607 CP(buf, old, shm_dtime); 1608 CP(buf, old, shm_ctime); 1609 old.shm_internal = NULL; 1610 error = copyout(&old, uap->buf, sizeof(old)); 1611 break; 1612 } 1613 1614 done: 1615 if (error) { 1616 /* Invalidate the return value */ 1617 td->td_retval[0] = -1; 1618 } 1619 return (error); 1620 } 1621 1622 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || 1623 COMPAT_FREEBSD7 */ 1624 1625 static int 1626 sysvshm_modload(struct module *module, int cmd, void *arg) 1627 { 1628 int error = 0; 1629 1630 switch (cmd) { 1631 case MOD_LOAD: 1632 error = shminit(); 1633 if (error != 0) 1634 shmunload(); 1635 break; 1636 case MOD_UNLOAD: 1637 error = shmunload(); 1638 break; 1639 case MOD_SHUTDOWN: 1640 break; 1641 default: 1642 error = EINVAL; 1643 break; 1644 } 1645 return (error); 1646 } 1647 1648 static moduledata_t sysvshm_mod = { 1649 "sysvshm", 1650 &sysvshm_modload, 1651 NULL 1652 }; 1653 1654 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST); 1655 MODULE_VERSION(sysvshm, 1); 1656