1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause AND BSD-2-Clause 3 * 4 * Copyright (c) 1994 Adam Glass and Charles Hannum. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. All advertising materials mentioning features or use of this software 15 * must display the following acknowledgement: 16 * This product includes software developed by Adam Glass and Charles 17 * Hannum. 18 * 4. The names of the authors may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 * 32 * $NetBSD: sysv_shm.c,v 1.39 1997/10/07 10:02:03 drochner Exp $ 33 */ 34 /*- 35 * Copyright (c) 2003-2005 McAfee, Inc. 36 * Copyright (c) 2016-2017 Robert N. M. Watson 37 * All rights reserved. 38 * 39 * This software was developed for the FreeBSD Project in part by McAfee 40 * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR 41 * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research 42 * program. 43 * 44 * Portions of this software were developed by BAE Systems, the University of 45 * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL 46 * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent 47 * Computing (TC) research program. 48 * 49 * Redistribution and use in source and binary forms, with or without 50 * modification, are permitted provided that the following conditions 51 * are met: 52 * 1. Redistributions of source code must retain the above copyright 53 * notice, this list of conditions and the following disclaimer. 54 * 2. Redistributions in binary form must reproduce the above copyright 55 * notice, this list of conditions and the following disclaimer in the 56 * documentation and/or other materials provided with the distribution. 57 * 58 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 61 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 68 * SUCH DAMAGE. 69 */ 70 71 #include <sys/cdefs.h> 72 #include "opt_sysvipc.h" 73 74 #include <sys/param.h> 75 #include <sys/systm.h> 76 #include <sys/abi_compat.h> 77 #include <sys/kernel.h> 78 #include <sys/limits.h> 79 #include <sys/lock.h> 80 #include <sys/sysctl.h> 81 #include <sys/shm.h> 82 #include <sys/proc.h> 83 #include <sys/malloc.h> 84 #include <sys/mman.h> 85 #include <sys/module.h> 86 #include <sys/mutex.h> 87 #include <sys/racct.h> 88 #include <sys/resourcevar.h> 89 #include <sys/rwlock.h> 90 #include <sys/stat.h> 91 #include <sys/syscall.h> 92 #include <sys/syscallsubr.h> 93 #include <sys/sysent.h> 94 #include <sys/sysproto.h> 95 #include <sys/jail.h> 96 97 #include <security/audit/audit.h> 98 #include <security/mac/mac_framework.h> 99 100 #include <vm/vm.h> 101 #include <vm/vm_param.h> 102 #include <vm/pmap.h> 103 #include <vm/vm_object.h> 104 #include <vm/vm_map.h> 105 #include <vm/vm_page.h> 106 #include <vm/vm_pager.h> 107 108 FEATURE(sysv_shm, "System V shared memory segments support"); 109 110 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments"); 111 112 #define SHMSEG_FREE 0x0200 113 #define SHMSEG_REMOVED 0x0400 114 #define SHMSEG_ALLOCATED 0x0800 115 116 static int shm_last_free, shm_nused, shmalloced; 117 vm_size_t shm_committed; 118 static struct shmid_kernel *shmsegs; 119 static unsigned shm_prison_slot; 120 121 struct shmmap_state { 122 vm_offset_t va; 123 int shmid; 124 }; 125 126 static void shm_deallocate_segment(struct shmid_kernel *); 127 static int shm_find_segment_by_key(struct prison *, key_t); 128 static struct shmid_kernel *shm_find_segment(struct prison *, int, bool); 129 static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *); 130 static int shmget_allocate_segment(struct thread *td, key_t key, size_t size, 131 int mode); 132 static int shmget_existing(struct thread *td, size_t size, int shmflg, 133 int mode, int segnum); 134 static void shmrealloc(void); 135 static int shminit(void); 136 static int sysvshm_modload(struct module *, int, void *); 137 static int shmunload(void); 138 #ifndef SYSVSHM 139 static void shmexit_myhook(struct vmspace *vm); 140 static void shmfork_myhook(struct proc *p1, struct proc *p2); 141 #endif 142 static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS); 143 static void shm_remove(struct shmid_kernel *, int); 144 static struct prison *shm_find_prison(struct ucred *); 145 static int shm_prison_cansee(struct prison *, struct shmid_kernel *); 146 static int shm_prison_check(void *, void *); 147 static int shm_prison_set(void *, void *); 148 static int shm_prison_get(void *, void *); 149 static int shm_prison_remove(void *, void *); 150 static void shm_prison_cleanup(struct prison *); 151 152 /* 153 * Tuneable values. 154 */ 155 #ifndef SHMMAXPGS 156 #define SHMMAXPGS 131072ul /* Note: sysv shared memory is swap backed. */ 157 #endif 158 #ifndef SHMMAX 159 #define SHMMAX (SHMMAXPGS*PAGE_SIZE) 160 #endif 161 #ifndef SHMMIN 162 #define SHMMIN 1 163 #endif 164 #ifndef SHMMNI 165 #define SHMMNI 192 166 #endif 167 #ifndef SHMSEG 168 #define SHMSEG 128 169 #endif 170 #ifndef SHMALL 171 #define SHMALL (SHMMAXPGS) 172 #endif 173 174 struct shminfo shminfo = { 175 .shmmax = SHMMAX, 176 .shmmin = SHMMIN, 177 .shmmni = SHMMNI, 178 .shmseg = SHMSEG, 179 .shmall = SHMALL 180 }; 181 182 static int shm_use_phys; 183 static int shm_allow_removed = 1; 184 185 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RWTUN, &shminfo.shmmax, 0, 186 "Maximum shared memory segment size"); 187 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RWTUN, &shminfo.shmmin, 0, 188 "Minimum shared memory segment size"); 189 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0, 190 "Number of shared memory identifiers"); 191 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0, 192 "Number of segments per process"); 193 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RWTUN, &shminfo.shmall, 0, 194 "Maximum number of pages available for shared memory"); 195 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RWTUN, 196 &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core"); 197 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RWTUN, 198 &shm_allow_removed, 0, 199 "Enable/Disable attachment to attached segments marked for removal"); 200 SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD | 201 CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "", 202 "Array of struct shmid_kernel for each potential shared memory segment"); 203 204 static struct sx sysvshmsx; 205 #define SYSVSHM_LOCK() sx_xlock(&sysvshmsx) 206 #define SYSVSHM_UNLOCK() sx_xunlock(&sysvshmsx) 207 #define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED) 208 209 static int 210 shm_find_segment_by_key(struct prison *pr, key_t key) 211 { 212 int i; 213 214 for (i = 0; i < shmalloced; i++) 215 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) && 216 shmsegs[i].cred != NULL && 217 shmsegs[i].cred->cr_prison == pr && 218 shmsegs[i].u.shm_perm.key == key) 219 return (i); 220 return (-1); 221 } 222 223 /* 224 * Finds segment either by shmid if is_shmid is true, or by segnum if 225 * is_shmid is false. 226 */ 227 static struct shmid_kernel * 228 shm_find_segment(struct prison *rpr, int arg, bool is_shmid) 229 { 230 struct shmid_kernel *shmseg; 231 int segnum; 232 233 segnum = is_shmid ? IPCID_TO_IX(arg) : arg; 234 if (segnum < 0 || segnum >= shmalloced) 235 return (NULL); 236 shmseg = &shmsegs[segnum]; 237 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 238 (!shm_allow_removed && 239 (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) || 240 (is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg)) || 241 shm_prison_cansee(rpr, shmseg) != 0) 242 return (NULL); 243 return (shmseg); 244 } 245 246 static void 247 shm_deallocate_segment(struct shmid_kernel *shmseg) 248 { 249 vm_size_t size; 250 251 SYSVSHM_ASSERT_LOCKED(); 252 253 vm_object_deallocate(shmseg->object); 254 shmseg->object = NULL; 255 size = round_page(shmseg->u.shm_segsz); 256 shm_committed -= btoc(size); 257 shm_nused--; 258 shmseg->u.shm_perm.mode = SHMSEG_FREE; 259 #ifdef MAC 260 mac_sysvshm_cleanup(shmseg); 261 #endif 262 racct_sub_cred(shmseg->cred, RACCT_NSHM, 1); 263 racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size); 264 crfree(shmseg->cred); 265 shmseg->cred = NULL; 266 } 267 268 static int 269 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s) 270 { 271 struct shmid_kernel *shmseg; 272 int segnum, result; 273 vm_size_t size; 274 275 SYSVSHM_ASSERT_LOCKED(); 276 segnum = IPCID_TO_IX(shmmap_s->shmid); 277 KASSERT(segnum >= 0 && segnum < shmalloced, 278 ("segnum %d shmalloced %d", segnum, shmalloced)); 279 280 shmseg = &shmsegs[segnum]; 281 size = round_page(shmseg->u.shm_segsz); 282 result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size); 283 if (result != KERN_SUCCESS) 284 return (EINVAL); 285 shmmap_s->shmid = -1; 286 shmseg->u.shm_dtime = time_second; 287 if (--shmseg->u.shm_nattch == 0 && 288 (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) { 289 shm_deallocate_segment(shmseg); 290 shm_last_free = segnum; 291 } 292 return (0); 293 } 294 295 static void 296 shm_remove(struct shmid_kernel *shmseg, int segnum) 297 { 298 299 shmseg->u.shm_perm.key = IPC_PRIVATE; 300 shmseg->u.shm_perm.mode |= SHMSEG_REMOVED; 301 if (shmseg->u.shm_nattch == 0) { 302 shm_deallocate_segment(shmseg); 303 shm_last_free = segnum; 304 } 305 } 306 307 static struct prison * 308 shm_find_prison(struct ucred *cred) 309 { 310 struct prison *pr, *rpr; 311 312 pr = cred->cr_prison; 313 prison_lock(pr); 314 rpr = osd_jail_get(pr, shm_prison_slot); 315 prison_unlock(pr); 316 return rpr; 317 } 318 319 static int 320 shm_prison_cansee(struct prison *rpr, struct shmid_kernel *shmseg) 321 { 322 323 if (shmseg->cred == NULL || 324 !(rpr == shmseg->cred->cr_prison || 325 prison_ischild(rpr, shmseg->cred->cr_prison))) 326 return (EINVAL); 327 return (0); 328 } 329 330 static int 331 kern_shmdt_locked(struct thread *td, const void *shmaddr) 332 { 333 struct proc *p = td->td_proc; 334 struct shmmap_state *shmmap_s; 335 #ifdef MAC 336 int error; 337 #endif 338 int i; 339 340 SYSVSHM_ASSERT_LOCKED(); 341 if (shm_find_prison(td->td_ucred) == NULL) 342 return (ENOSYS); 343 shmmap_s = p->p_vmspace->vm_shm; 344 if (shmmap_s == NULL) 345 return (EINVAL); 346 AUDIT_ARG_SVIPC_ID(shmmap_s->shmid); 347 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 348 if (shmmap_s->shmid != -1 && 349 shmmap_s->va == (vm_offset_t)shmaddr) { 350 break; 351 } 352 } 353 if (i == shminfo.shmseg) 354 return (EINVAL); 355 #ifdef MAC 356 error = mac_sysvshm_check_shmdt(td->td_ucred, 357 &shmsegs[IPCID_TO_IX(shmmap_s->shmid)]); 358 if (error != 0) 359 return (error); 360 #endif 361 return (shm_delete_mapping(p->p_vmspace, shmmap_s)); 362 } 363 364 #ifndef _SYS_SYSPROTO_H_ 365 struct shmdt_args { 366 const void *shmaddr; 367 }; 368 #endif 369 int 370 sys_shmdt(struct thread *td, struct shmdt_args *uap) 371 { 372 int error; 373 374 SYSVSHM_LOCK(); 375 error = kern_shmdt_locked(td, uap->shmaddr); 376 SYSVSHM_UNLOCK(); 377 return (error); 378 } 379 380 static int 381 kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr, 382 int shmflg) 383 { 384 struct prison *rpr; 385 struct proc *p = td->td_proc; 386 struct shmid_kernel *shmseg; 387 struct shmmap_state *shmmap_s; 388 vm_offset_t attach_va; 389 vm_prot_t prot; 390 vm_size_t size; 391 int cow, error, find_space, i, rv; 392 393 AUDIT_ARG_SVIPC_ID(shmid); 394 AUDIT_ARG_VALUE(shmflg); 395 396 SYSVSHM_ASSERT_LOCKED(); 397 rpr = shm_find_prison(td->td_ucred); 398 if (rpr == NULL) 399 return (ENOSYS); 400 shmmap_s = p->p_vmspace->vm_shm; 401 if (shmmap_s == NULL) { 402 shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state), 403 M_SHM, M_WAITOK); 404 for (i = 0; i < shminfo.shmseg; i++) 405 shmmap_s[i].shmid = -1; 406 KASSERT(p->p_vmspace->vm_shm == NULL, ("raced")); 407 p->p_vmspace->vm_shm = shmmap_s; 408 } 409 shmseg = shm_find_segment(rpr, shmid, true); 410 if (shmseg == NULL) 411 return (EINVAL); 412 error = ipcperm(td, &shmseg->u.shm_perm, 413 (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); 414 if (error != 0) 415 return (error); 416 #ifdef MAC 417 error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg); 418 if (error != 0) 419 return (error); 420 #endif 421 for (i = 0; i < shminfo.shmseg; i++) { 422 if (shmmap_s->shmid == -1) 423 break; 424 shmmap_s++; 425 } 426 if (i >= shminfo.shmseg) 427 return (EMFILE); 428 size = round_page(shmseg->u.shm_segsz); 429 prot = VM_PROT_READ; 430 cow = MAP_INHERIT_SHARE | MAP_PREFAULT_PARTIAL; 431 if ((shmflg & SHM_RDONLY) == 0) 432 prot |= VM_PROT_WRITE; 433 if (shmaddr != NULL) { 434 if ((shmflg & SHM_RND) != 0) 435 attach_va = rounddown2((vm_offset_t)shmaddr, SHMLBA); 436 else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0) 437 attach_va = (vm_offset_t)shmaddr; 438 else 439 return (EINVAL); 440 if ((shmflg & SHM_REMAP) != 0) 441 cow |= MAP_REMAP; 442 find_space = VMFS_NO_SPACE; 443 } else { 444 /* 445 * This is just a hint to vm_map_find() about where to 446 * put it. 447 */ 448 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 449 lim_max(td, RLIMIT_DATA)); 450 find_space = VMFS_OPTIMAL_SPACE; 451 } 452 453 vm_object_reference(shmseg->object); 454 rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object, 0, &attach_va, 455 size, 0, find_space, prot, prot, cow); 456 if (rv != KERN_SUCCESS) { 457 vm_object_deallocate(shmseg->object); 458 return (ENOMEM); 459 } 460 461 shmmap_s->va = attach_va; 462 shmmap_s->shmid = shmid; 463 shmseg->u.shm_lpid = p->p_pid; 464 shmseg->u.shm_atime = time_second; 465 shmseg->u.shm_nattch++; 466 td->td_retval[0] = attach_va; 467 return (error); 468 } 469 470 int 471 kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg) 472 { 473 int error; 474 475 SYSVSHM_LOCK(); 476 error = kern_shmat_locked(td, shmid, shmaddr, shmflg); 477 SYSVSHM_UNLOCK(); 478 return (error); 479 } 480 481 #ifndef _SYS_SYSPROTO_H_ 482 struct shmat_args { 483 int shmid; 484 const void *shmaddr; 485 int shmflg; 486 }; 487 #endif 488 int 489 sys_shmat(struct thread *td, struct shmat_args *uap) 490 { 491 492 return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg)); 493 } 494 495 static int 496 kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf, 497 size_t *bufsz) 498 { 499 struct prison *rpr; 500 struct shmid_kernel *shmseg; 501 struct shmid_ds *shmidp; 502 struct shm_info shm_info; 503 int error; 504 505 SYSVSHM_ASSERT_LOCKED(); 506 507 rpr = shm_find_prison(td->td_ucred); 508 if (rpr == NULL) 509 return (ENOSYS); 510 511 AUDIT_ARG_SVIPC_ID(shmid); 512 AUDIT_ARG_SVIPC_CMD(cmd); 513 514 switch (cmd) { 515 /* 516 * It is possible that kern_shmctl is being called from the Linux ABI 517 * layer, in which case, we will need to implement IPC_INFO. It should 518 * be noted that other shmctl calls will be funneled through here for 519 * Linix binaries as well. 520 * 521 * NB: The Linux ABI layer will convert this data to structure(s) more 522 * consistent with the Linux ABI. 523 */ 524 case IPC_INFO: 525 memcpy(buf, &shminfo, sizeof(shminfo)); 526 if (bufsz) 527 *bufsz = sizeof(shminfo); 528 td->td_retval[0] = shmalloced; 529 return (0); 530 case SHM_INFO: { 531 shm_info.used_ids = shm_nused; 532 shm_info.shm_rss = 0; /*XXX where to get from ? */ 533 shm_info.shm_tot = 0; /*XXX where to get from ? */ 534 shm_info.shm_swp = 0; /*XXX where to get from ? */ 535 shm_info.swap_attempts = 0; /*XXX where to get from ? */ 536 shm_info.swap_successes = 0; /*XXX where to get from ? */ 537 memcpy(buf, &shm_info, sizeof(shm_info)); 538 if (bufsz != NULL) 539 *bufsz = sizeof(shm_info); 540 td->td_retval[0] = shmalloced; 541 return (0); 542 } 543 } 544 shmseg = shm_find_segment(rpr, shmid, cmd != SHM_STAT); 545 if (shmseg == NULL) 546 return (EINVAL); 547 #ifdef MAC 548 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd); 549 if (error != 0) 550 return (error); 551 #endif 552 switch (cmd) { 553 case SHM_STAT: 554 case IPC_STAT: 555 shmidp = (struct shmid_ds *)buf; 556 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 557 if (error != 0) 558 return (error); 559 memcpy(shmidp, &shmseg->u, sizeof(struct shmid_ds)); 560 if (td->td_ucred->cr_prison != shmseg->cred->cr_prison) 561 shmidp->shm_perm.key = IPC_PRIVATE; 562 if (bufsz != NULL) 563 *bufsz = sizeof(struct shmid_ds); 564 if (cmd == SHM_STAT) { 565 td->td_retval[0] = IXSEQ_TO_IPCID(shmid, 566 shmseg->u.shm_perm); 567 } 568 break; 569 case IPC_SET: 570 shmidp = (struct shmid_ds *)buf; 571 AUDIT_ARG_SVIPC_PERM(&shmidp->shm_perm); 572 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); 573 if (error != 0) 574 return (error); 575 shmseg->u.shm_perm.uid = shmidp->shm_perm.uid; 576 shmseg->u.shm_perm.gid = shmidp->shm_perm.gid; 577 shmseg->u.shm_perm.mode = 578 (shmseg->u.shm_perm.mode & ~ACCESSPERMS) | 579 (shmidp->shm_perm.mode & ACCESSPERMS); 580 shmseg->u.shm_ctime = time_second; 581 break; 582 case IPC_RMID: 583 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); 584 if (error != 0) 585 return (error); 586 shm_remove(shmseg, IPCID_TO_IX(shmid)); 587 break; 588 #if 0 589 case SHM_LOCK: 590 case SHM_UNLOCK: 591 #endif 592 default: 593 error = EINVAL; 594 break; 595 } 596 return (error); 597 } 598 599 int 600 kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz) 601 { 602 int error; 603 604 SYSVSHM_LOCK(); 605 error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz); 606 SYSVSHM_UNLOCK(); 607 return (error); 608 } 609 610 #ifndef _SYS_SYSPROTO_H_ 611 struct shmctl_args { 612 int shmid; 613 int cmd; 614 struct shmid_ds *buf; 615 }; 616 #endif 617 int 618 sys_shmctl(struct thread *td, struct shmctl_args *uap) 619 { 620 int error; 621 struct shmid_ds buf; 622 size_t bufsz; 623 624 /* 625 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 626 * Linux binaries. If we see the call come through the FreeBSD ABI, 627 * return an error back to the user since we do not to support this. 628 */ 629 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 630 uap->cmd == SHM_STAT) 631 return (EINVAL); 632 633 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 634 if (uap->cmd == IPC_SET) { 635 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds)))) 636 goto done; 637 } 638 639 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 640 if (error) 641 goto done; 642 643 /* Cases in which we need to copyout */ 644 switch (uap->cmd) { 645 case IPC_STAT: 646 error = copyout(&buf, uap->buf, bufsz); 647 break; 648 } 649 650 done: 651 if (error) { 652 /* Invalidate the return value */ 653 td->td_retval[0] = -1; 654 } 655 return (error); 656 } 657 658 static int 659 shmget_existing(struct thread *td, size_t size, int shmflg, int mode, 660 int segnum) 661 { 662 struct shmid_kernel *shmseg; 663 #ifdef MAC 664 int error; 665 #endif 666 667 SYSVSHM_ASSERT_LOCKED(); 668 KASSERT(segnum >= 0 && segnum < shmalloced, 669 ("segnum %d shmalloced %d", segnum, shmalloced)); 670 shmseg = &shmsegs[segnum]; 671 if ((shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) 672 return (EEXIST); 673 #ifdef MAC 674 error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, shmflg); 675 if (error != 0) 676 return (error); 677 #endif 678 if (size != 0 && size > shmseg->u.shm_segsz) 679 return (EINVAL); 680 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 681 return (0); 682 } 683 684 static int 685 shmget_allocate_segment(struct thread *td, key_t key, size_t size, int mode) 686 { 687 struct ucred *cred = td->td_ucred; 688 struct shmid_kernel *shmseg; 689 vm_object_t shm_object; 690 int i, segnum; 691 692 SYSVSHM_ASSERT_LOCKED(); 693 694 if (size < shminfo.shmmin || size > shminfo.shmmax) 695 return (EINVAL); 696 if (shm_nused >= shminfo.shmmni) /* Any shmids left? */ 697 return (ENOSPC); 698 size = round_page(size); 699 if (shm_committed + btoc(size) > shminfo.shmall) 700 return (ENOMEM); 701 if (shm_last_free < 0) { 702 shmrealloc(); /* Maybe expand the shmsegs[] array. */ 703 for (i = 0; i < shmalloced; i++) 704 if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE) 705 break; 706 if (i == shmalloced) 707 return (ENOSPC); 708 segnum = i; 709 } else { 710 segnum = shm_last_free; 711 shm_last_free = -1; 712 } 713 KASSERT(segnum >= 0 && segnum < shmalloced, 714 ("segnum %d shmalloced %d", segnum, shmalloced)); 715 shmseg = &shmsegs[segnum]; 716 #ifdef RACCT 717 if (racct_enable) { 718 PROC_LOCK(td->td_proc); 719 if (racct_add(td->td_proc, RACCT_NSHM, 1)) { 720 PROC_UNLOCK(td->td_proc); 721 return (ENOSPC); 722 } 723 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) { 724 racct_sub(td->td_proc, RACCT_NSHM, 1); 725 PROC_UNLOCK(td->td_proc); 726 return (ENOMEM); 727 } 728 PROC_UNLOCK(td->td_proc); 729 } 730 #endif 731 732 /* 733 * We make sure that we have allocated a pager before we need 734 * to. 735 */ 736 shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP, 737 0, size, VM_PROT_DEFAULT, 0, cred); 738 if (shm_object == NULL) { 739 #ifdef RACCT 740 if (racct_enable) { 741 PROC_LOCK(td->td_proc); 742 racct_sub(td->td_proc, RACCT_NSHM, 1); 743 racct_sub(td->td_proc, RACCT_SHMSIZE, size); 744 PROC_UNLOCK(td->td_proc); 745 } 746 #endif 747 return (ENOMEM); 748 } 749 750 shmseg->object = shm_object; 751 shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid; 752 shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid; 753 shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; 754 shmseg->u.shm_perm.key = key; 755 shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff; 756 shmseg->cred = crhold(cred); 757 shmseg->u.shm_segsz = size; 758 shmseg->u.shm_cpid = td->td_proc->p_pid; 759 shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0; 760 shmseg->u.shm_atime = shmseg->u.shm_dtime = 0; 761 #ifdef MAC 762 mac_sysvshm_create(cred, shmseg); 763 #endif 764 shmseg->u.shm_ctime = time_second; 765 shm_committed += btoc(size); 766 shm_nused++; 767 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 768 769 return (0); 770 } 771 772 #ifndef _SYS_SYSPROTO_H_ 773 struct shmget_args { 774 key_t key; 775 size_t size; 776 int shmflg; 777 }; 778 #endif 779 int 780 sys_shmget(struct thread *td, struct shmget_args *uap) 781 { 782 int segnum, mode; 783 int error; 784 785 if (shm_find_prison(td->td_ucred) == NULL) 786 return (ENOSYS); 787 mode = uap->shmflg & ACCESSPERMS; 788 SYSVSHM_LOCK(); 789 if (uap->key == IPC_PRIVATE) { 790 error = shmget_allocate_segment(td, uap->key, uap->size, mode); 791 } else { 792 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison, 793 uap->key); 794 if (segnum >= 0) 795 error = shmget_existing(td, uap->size, uap->shmflg, 796 mode, segnum); 797 else if ((uap->shmflg & IPC_CREAT) == 0) 798 error = ENOENT; 799 else 800 error = shmget_allocate_segment(td, uap->key, 801 uap->size, mode); 802 } 803 SYSVSHM_UNLOCK(); 804 return (error); 805 } 806 807 #ifdef SYSVSHM 808 void 809 shmfork(struct proc *p1, struct proc *p2) 810 #else 811 static void 812 shmfork_myhook(struct proc *p1, struct proc *p2) 813 #endif 814 { 815 struct shmmap_state *shmmap_s; 816 size_t size; 817 int i; 818 819 SYSVSHM_LOCK(); 820 size = shminfo.shmseg * sizeof(struct shmmap_state); 821 shmmap_s = malloc(size, M_SHM, M_WAITOK); 822 bcopy(p1->p_vmspace->vm_shm, shmmap_s, size); 823 p2->p_vmspace->vm_shm = shmmap_s; 824 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 825 if (shmmap_s->shmid != -1) { 826 KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 && 827 IPCID_TO_IX(shmmap_s->shmid) < shmalloced, 828 ("segnum %d shmalloced %d", 829 IPCID_TO_IX(shmmap_s->shmid), shmalloced)); 830 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++; 831 } 832 } 833 SYSVSHM_UNLOCK(); 834 } 835 836 #ifdef SYSVSHM 837 void 838 shmexit(struct vmspace *vm) 839 #else 840 static void 841 shmexit_myhook(struct vmspace *vm) 842 #endif 843 { 844 struct shmmap_state *base, *shm; 845 int i; 846 847 base = vm->vm_shm; 848 if (base != NULL) { 849 vm->vm_shm = NULL; 850 SYSVSHM_LOCK(); 851 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) { 852 if (shm->shmid != -1) 853 shm_delete_mapping(vm, shm); 854 } 855 SYSVSHM_UNLOCK(); 856 free(base, M_SHM); 857 } 858 } 859 860 static void 861 shmrealloc(void) 862 { 863 struct shmid_kernel *newsegs; 864 int i; 865 866 SYSVSHM_ASSERT_LOCKED(); 867 868 if (shmalloced >= shminfo.shmmni) 869 return; 870 871 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, 872 M_WAITOK | M_ZERO); 873 for (i = 0; i < shmalloced; i++) 874 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 875 for (; i < shminfo.shmmni; i++) { 876 newsegs[i].u.shm_perm.mode = SHMSEG_FREE; 877 newsegs[i].u.shm_perm.seq = 0; 878 #ifdef MAC 879 mac_sysvshm_init(&newsegs[i]); 880 #endif 881 } 882 free(shmsegs, M_SHM); 883 shmsegs = newsegs; 884 shmalloced = shminfo.shmmni; 885 } 886 887 static struct syscall_helper_data shm_syscalls[] = { 888 SYSCALL_INIT_HELPER(shmat), 889 SYSCALL_INIT_HELPER(shmctl), 890 SYSCALL_INIT_HELPER(shmdt), 891 SYSCALL_INIT_HELPER(shmget), 892 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 893 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 894 SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl), 895 #endif 896 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 897 SYSCALL_INIT_HELPER(shmsys), 898 #endif 899 SYSCALL_INIT_LAST 900 }; 901 902 #ifdef COMPAT_FREEBSD32 903 #include <compat/freebsd32/freebsd32.h> 904 #include <compat/freebsd32/freebsd32_ipc.h> 905 #include <compat/freebsd32/freebsd32_proto.h> 906 #include <compat/freebsd32/freebsd32_signal.h> 907 #include <compat/freebsd32/freebsd32_syscall.h> 908 #include <compat/freebsd32/freebsd32_util.h> 909 910 static struct syscall_helper_data shm32_syscalls[] = { 911 SYSCALL32_INIT_HELPER_COMPAT(shmat), 912 SYSCALL32_INIT_HELPER_COMPAT(shmdt), 913 SYSCALL32_INIT_HELPER_COMPAT(shmget), 914 SYSCALL32_INIT_HELPER(freebsd32_shmsys), 915 SYSCALL32_INIT_HELPER(freebsd32_shmctl), 916 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 917 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 918 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl), 919 #endif 920 SYSCALL_INIT_LAST 921 }; 922 #endif 923 924 static int 925 shminit(void) 926 { 927 struct prison *pr; 928 void **rsv; 929 int i, error; 930 osd_method_t methods[PR_MAXMETHOD] = { 931 [PR_METHOD_CHECK] = shm_prison_check, 932 [PR_METHOD_SET] = shm_prison_set, 933 [PR_METHOD_GET] = shm_prison_get, 934 [PR_METHOD_REMOVE] = shm_prison_remove, 935 }; 936 937 #ifndef BURN_BRIDGES 938 if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0) 939 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n"); 940 #endif 941 if (shminfo.shmmax == SHMMAX) { 942 /* Initialize shmmax dealing with possible overflow. */ 943 for (i = PAGE_SIZE; i != 0; i--) { 944 shminfo.shmmax = shminfo.shmall * i; 945 if ((shminfo.shmmax / shminfo.shmall) == (u_long)i) 946 break; 947 } 948 } 949 shmalloced = shminfo.shmmni; 950 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, 951 M_WAITOK|M_ZERO); 952 for (i = 0; i < shmalloced; i++) { 953 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; 954 shmsegs[i].u.shm_perm.seq = 0; 955 #ifdef MAC 956 mac_sysvshm_init(&shmsegs[i]); 957 #endif 958 } 959 shm_last_free = 0; 960 shm_nused = 0; 961 shm_committed = 0; 962 sx_init(&sysvshmsx, "sysvshmsx"); 963 #ifndef SYSVSHM 964 shmexit_hook = &shmexit_myhook; 965 shmfork_hook = &shmfork_myhook; 966 #endif 967 968 /* Set current prisons according to their allow.sysvipc. */ 969 shm_prison_slot = osd_jail_register(NULL, methods); 970 rsv = osd_reserve(shm_prison_slot); 971 prison_lock(&prison0); 972 (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0); 973 prison_unlock(&prison0); 974 rsv = NULL; 975 sx_slock(&allprison_lock); 976 TAILQ_FOREACH(pr, &allprison, pr_list) { 977 if (rsv == NULL) 978 rsv = osd_reserve(shm_prison_slot); 979 prison_lock(pr); 980 if (pr->pr_allow & PR_ALLOW_SYSVIPC) { 981 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 982 &prison0); 983 rsv = NULL; 984 } 985 prison_unlock(pr); 986 } 987 if (rsv != NULL) 988 osd_free_reserved(rsv); 989 sx_sunlock(&allprison_lock); 990 991 error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD); 992 if (error != 0) 993 return (error); 994 #ifdef COMPAT_FREEBSD32 995 error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD); 996 if (error != 0) 997 return (error); 998 #endif 999 return (0); 1000 } 1001 1002 static int 1003 shmunload(void) 1004 { 1005 int i; 1006 1007 if (shm_nused > 0) 1008 return (EBUSY); 1009 1010 #ifdef COMPAT_FREEBSD32 1011 syscall32_helper_unregister(shm32_syscalls); 1012 #endif 1013 syscall_helper_unregister(shm_syscalls); 1014 if (shm_prison_slot != 0) 1015 osd_jail_deregister(shm_prison_slot); 1016 1017 for (i = 0; i < shmalloced; i++) { 1018 #ifdef MAC 1019 mac_sysvshm_destroy(&shmsegs[i]); 1020 #endif 1021 /* 1022 * Objects might be still mapped into the processes 1023 * address spaces. Actual free would happen on the 1024 * last mapping destruction. 1025 */ 1026 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE) 1027 vm_object_deallocate(shmsegs[i].object); 1028 } 1029 free(shmsegs, M_SHM); 1030 #ifndef SYSVSHM 1031 shmexit_hook = NULL; 1032 shmfork_hook = NULL; 1033 #endif 1034 sx_destroy(&sysvshmsx); 1035 return (0); 1036 } 1037 1038 static int 1039 sysctl_shmsegs(SYSCTL_HANDLER_ARGS) 1040 { 1041 struct shmid_kernel tshmseg; 1042 #ifdef COMPAT_FREEBSD32 1043 struct shmid_kernel32 tshmseg32; 1044 #endif 1045 struct prison *pr, *rpr; 1046 void *outaddr; 1047 size_t outsize; 1048 int error, i; 1049 1050 SYSVSHM_LOCK(); 1051 pr = req->td->td_ucred->cr_prison; 1052 rpr = shm_find_prison(req->td->td_ucred); 1053 error = 0; 1054 for (i = 0; i < shmalloced; i++) { 1055 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 1056 rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) { 1057 bzero(&tshmseg, sizeof(tshmseg)); 1058 tshmseg.u.shm_perm.mode = SHMSEG_FREE; 1059 } else { 1060 tshmseg = shmsegs[i]; 1061 if (tshmseg.cred->cr_prison != pr) 1062 tshmseg.u.shm_perm.key = IPC_PRIVATE; 1063 } 1064 #ifdef COMPAT_FREEBSD32 1065 if (SV_CURPROC_FLAG(SV_ILP32)) { 1066 bzero(&tshmseg32, sizeof(tshmseg32)); 1067 freebsd32_ipcperm_out(&tshmseg.u.shm_perm, 1068 &tshmseg32.u.shm_perm); 1069 CP(tshmseg, tshmseg32, u.shm_segsz); 1070 CP(tshmseg, tshmseg32, u.shm_lpid); 1071 CP(tshmseg, tshmseg32, u.shm_cpid); 1072 CP(tshmseg, tshmseg32, u.shm_nattch); 1073 CP(tshmseg, tshmseg32, u.shm_atime); 1074 CP(tshmseg, tshmseg32, u.shm_dtime); 1075 CP(tshmseg, tshmseg32, u.shm_ctime); 1076 /* Don't copy object, label, or cred */ 1077 outaddr = &tshmseg32; 1078 outsize = sizeof(tshmseg32); 1079 } else 1080 #endif 1081 { 1082 tshmseg.object = NULL; 1083 tshmseg.label = NULL; 1084 tshmseg.cred = NULL; 1085 outaddr = &tshmseg; 1086 outsize = sizeof(tshmseg); 1087 } 1088 error = SYSCTL_OUT(req, outaddr, outsize); 1089 if (error != 0) 1090 break; 1091 } 1092 SYSVSHM_UNLOCK(); 1093 return (error); 1094 } 1095 1096 static int 1097 shm_prison_check(void *obj, void *data) 1098 { 1099 struct prison *pr = obj; 1100 struct prison *prpr; 1101 struct vfsoptlist *opts = data; 1102 int error, jsys; 1103 1104 /* 1105 * sysvshm is a jailsys integer. 1106 * It must be "disable" if the parent jail is disabled. 1107 */ 1108 error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1109 if (error != ENOENT) { 1110 if (error != 0) 1111 return (error); 1112 switch (jsys) { 1113 case JAIL_SYS_DISABLE: 1114 break; 1115 case JAIL_SYS_NEW: 1116 case JAIL_SYS_INHERIT: 1117 prison_lock(pr->pr_parent); 1118 prpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1119 prison_unlock(pr->pr_parent); 1120 if (prpr == NULL) 1121 return (EPERM); 1122 break; 1123 default: 1124 return (EINVAL); 1125 } 1126 } 1127 1128 return (0); 1129 } 1130 1131 static int 1132 shm_prison_set(void *obj, void *data) 1133 { 1134 struct prison *pr = obj; 1135 struct prison *tpr, *orpr, *nrpr, *trpr; 1136 struct vfsoptlist *opts = data; 1137 void *rsv; 1138 int jsys, descend; 1139 1140 /* 1141 * sysvshm controls which jail is the root of the associated segments 1142 * (this jail or same as the parent), or if the feature is available 1143 * at all. 1144 */ 1145 if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT) 1146 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0) 1147 ? JAIL_SYS_INHERIT 1148 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0) 1149 ? JAIL_SYS_DISABLE 1150 : -1; 1151 if (jsys == JAIL_SYS_DISABLE) { 1152 prison_lock(pr); 1153 orpr = osd_jail_get(pr, shm_prison_slot); 1154 if (orpr != NULL) 1155 osd_jail_del(pr, shm_prison_slot); 1156 prison_unlock(pr); 1157 if (orpr != NULL) { 1158 if (orpr == pr) 1159 shm_prison_cleanup(pr); 1160 /* Disable all child jails as well. */ 1161 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1162 prison_lock(tpr); 1163 trpr = osd_jail_get(tpr, shm_prison_slot); 1164 if (trpr != NULL) { 1165 osd_jail_del(tpr, shm_prison_slot); 1166 prison_unlock(tpr); 1167 if (trpr == tpr) 1168 shm_prison_cleanup(tpr); 1169 } else { 1170 prison_unlock(tpr); 1171 descend = 0; 1172 } 1173 } 1174 } 1175 } else if (jsys != -1) { 1176 if (jsys == JAIL_SYS_NEW) 1177 nrpr = pr; 1178 else { 1179 prison_lock(pr->pr_parent); 1180 nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1181 prison_unlock(pr->pr_parent); 1182 } 1183 rsv = osd_reserve(shm_prison_slot); 1184 prison_lock(pr); 1185 orpr = osd_jail_get(pr, shm_prison_slot); 1186 if (orpr != nrpr) 1187 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 1188 nrpr); 1189 else 1190 osd_free_reserved(rsv); 1191 prison_unlock(pr); 1192 if (orpr != nrpr) { 1193 if (orpr == pr) 1194 shm_prison_cleanup(pr); 1195 if (orpr != NULL) { 1196 /* Change child jails matching the old root, */ 1197 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1198 prison_lock(tpr); 1199 trpr = osd_jail_get(tpr, 1200 shm_prison_slot); 1201 if (trpr == orpr) { 1202 (void)osd_jail_set(tpr, 1203 shm_prison_slot, nrpr); 1204 prison_unlock(tpr); 1205 if (trpr == tpr) 1206 shm_prison_cleanup(tpr); 1207 } else { 1208 prison_unlock(tpr); 1209 descend = 0; 1210 } 1211 } 1212 } 1213 } 1214 } 1215 1216 return (0); 1217 } 1218 1219 static int 1220 shm_prison_get(void *obj, void *data) 1221 { 1222 struct prison *pr = obj; 1223 struct prison *rpr; 1224 struct vfsoptlist *opts = data; 1225 int error, jsys; 1226 1227 /* Set sysvshm based on the jail's root prison. */ 1228 prison_lock(pr); 1229 rpr = osd_jail_get(pr, shm_prison_slot); 1230 prison_unlock(pr); 1231 jsys = rpr == NULL ? JAIL_SYS_DISABLE 1232 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT; 1233 error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1234 if (error == ENOENT) 1235 error = 0; 1236 return (error); 1237 } 1238 1239 static int 1240 shm_prison_remove(void *obj, void *data __unused) 1241 { 1242 struct prison *pr = obj; 1243 struct prison *rpr; 1244 1245 SYSVSHM_LOCK(); 1246 prison_lock(pr); 1247 rpr = osd_jail_get(pr, shm_prison_slot); 1248 prison_unlock(pr); 1249 if (rpr == pr) 1250 shm_prison_cleanup(pr); 1251 SYSVSHM_UNLOCK(); 1252 return (0); 1253 } 1254 1255 static void 1256 shm_prison_cleanup(struct prison *pr) 1257 { 1258 struct shmid_kernel *shmseg; 1259 int i; 1260 1261 /* Remove any segments that belong to this jail. */ 1262 for (i = 0; i < shmalloced; i++) { 1263 shmseg = &shmsegs[i]; 1264 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) && 1265 shmseg->cred != NULL && shmseg->cred->cr_prison == pr) { 1266 shm_remove(shmseg, i); 1267 } 1268 } 1269 } 1270 1271 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory"); 1272 1273 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 1274 struct oshmid_ds { 1275 struct ipc_perm_old shm_perm; /* operation perms */ 1276 int shm_segsz; /* size of segment (bytes) */ 1277 u_short shm_cpid; /* pid, creator */ 1278 u_short shm_lpid; /* pid, last operation */ 1279 short shm_nattch; /* no. of current attaches */ 1280 time_t shm_atime; /* last attach time */ 1281 time_t shm_dtime; /* last detach time */ 1282 time_t shm_ctime; /* last change time */ 1283 void *shm_handle; /* internal handle for shm segment */ 1284 }; 1285 1286 struct oshmctl_args { 1287 int shmid; 1288 int cmd; 1289 struct oshmid_ds *ubuf; 1290 }; 1291 1292 static int 1293 oshmctl(struct thread *td, struct oshmctl_args *uap) 1294 { 1295 #ifdef COMPAT_43 1296 int error = 0; 1297 struct prison *rpr; 1298 struct shmid_kernel *shmseg; 1299 struct oshmid_ds outbuf; 1300 1301 rpr = shm_find_prison(td->td_ucred); 1302 if (rpr == NULL) 1303 return (ENOSYS); 1304 if (uap->cmd != IPC_STAT) { 1305 return (freebsd7_shmctl(td, 1306 (struct freebsd7_shmctl_args *)uap)); 1307 } 1308 SYSVSHM_LOCK(); 1309 shmseg = shm_find_segment(rpr, uap->shmid, true); 1310 if (shmseg == NULL) { 1311 SYSVSHM_UNLOCK(); 1312 return (EINVAL); 1313 } 1314 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 1315 if (error != 0) { 1316 SYSVSHM_UNLOCK(); 1317 return (error); 1318 } 1319 #ifdef MAC 1320 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd); 1321 if (error != 0) { 1322 SYSVSHM_UNLOCK(); 1323 return (error); 1324 } 1325 #endif 1326 ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm); 1327 outbuf.shm_segsz = shmseg->u.shm_segsz; 1328 outbuf.shm_cpid = shmseg->u.shm_cpid; 1329 outbuf.shm_lpid = shmseg->u.shm_lpid; 1330 outbuf.shm_nattch = shmseg->u.shm_nattch; 1331 outbuf.shm_atime = shmseg->u.shm_atime; 1332 outbuf.shm_dtime = shmseg->u.shm_dtime; 1333 outbuf.shm_ctime = shmseg->u.shm_ctime; 1334 outbuf.shm_handle = shmseg->object; 1335 SYSVSHM_UNLOCK(); 1336 return (copyout(&outbuf, uap->ubuf, sizeof(outbuf))); 1337 #else 1338 return (EINVAL); 1339 #endif 1340 } 1341 1342 /* XXX casting to (sy_call_t *) is bogus, as usual. */ 1343 static sy_call_t *shmcalls[] = { 1344 (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl, 1345 (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget, 1346 (sy_call_t *)freebsd7_shmctl 1347 }; 1348 1349 #ifndef _SYS_SYSPROTO_H_ 1350 /* XXX actually varargs. */ 1351 struct shmsys_args { 1352 int which; 1353 int a2; 1354 int a3; 1355 int a4; 1356 }; 1357 #endif 1358 int 1359 sys_shmsys(struct thread *td, struct shmsys_args *uap) 1360 { 1361 1362 AUDIT_ARG_SVIPC_WHICH(uap->which); 1363 if (uap->which < 0 || uap->which >= nitems(shmcalls)) 1364 return (EINVAL); 1365 return ((*shmcalls[uap->which])(td, &uap->a2)); 1366 } 1367 1368 #endif /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */ 1369 1370 #ifdef COMPAT_FREEBSD32 1371 1372 int 1373 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap) 1374 { 1375 1376 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1377 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1378 AUDIT_ARG_SVIPC_WHICH(uap->which); 1379 switch (uap->which) { 1380 case 0: { /* shmat */ 1381 struct shmat_args ap; 1382 1383 ap.shmid = uap->a2; 1384 ap.shmaddr = PTRIN(uap->a3); 1385 ap.shmflg = uap->a4; 1386 return (sysent[SYS_shmat].sy_call(td, &ap)); 1387 } 1388 case 2: { /* shmdt */ 1389 struct shmdt_args ap; 1390 1391 ap.shmaddr = PTRIN(uap->a2); 1392 return (sysent[SYS_shmdt].sy_call(td, &ap)); 1393 } 1394 case 3: { /* shmget */ 1395 struct shmget_args ap; 1396 1397 ap.key = uap->a2; 1398 ap.size = uap->a3; 1399 ap.shmflg = uap->a4; 1400 return (sysent[SYS_shmget].sy_call(td, &ap)); 1401 } 1402 case 4: { /* shmctl */ 1403 struct freebsd7_freebsd32_shmctl_args ap; 1404 1405 ap.shmid = uap->a2; 1406 ap.cmd = uap->a3; 1407 ap.buf = PTRIN(uap->a4); 1408 return (freebsd7_freebsd32_shmctl(td, &ap)); 1409 } 1410 case 1: /* oshmctl */ 1411 default: 1412 return (EINVAL); 1413 } 1414 #else 1415 return (nosys(td, NULL)); 1416 #endif 1417 } 1418 1419 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1420 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1421 int 1422 freebsd7_freebsd32_shmctl(struct thread *td, 1423 struct freebsd7_freebsd32_shmctl_args *uap) 1424 { 1425 int error; 1426 union { 1427 struct shmid_ds shmid_ds; 1428 struct shm_info shm_info; 1429 struct shminfo shminfo; 1430 } u; 1431 union { 1432 struct shmid_ds_old32 shmid_ds32; 1433 struct shm_info32 shm_info32; 1434 struct shminfo32 shminfo32; 1435 } u32; 1436 size_t sz; 1437 1438 if (uap->cmd == IPC_SET) { 1439 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1440 sizeof(u32.shmid_ds32)))) 1441 goto done; 1442 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm, 1443 &u.shmid_ds.shm_perm); 1444 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1445 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1446 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1447 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1448 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1449 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1450 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1451 } 1452 1453 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1454 if (error) 1455 goto done; 1456 1457 /* Cases in which we need to copyout */ 1458 switch (uap->cmd) { 1459 case IPC_INFO: 1460 CP(u.shminfo, u32.shminfo32, shmmax); 1461 CP(u.shminfo, u32.shminfo32, shmmin); 1462 CP(u.shminfo, u32.shminfo32, shmmni); 1463 CP(u.shminfo, u32.shminfo32, shmseg); 1464 CP(u.shminfo, u32.shminfo32, shmall); 1465 error = copyout(&u32.shminfo32, uap->buf, 1466 sizeof(u32.shminfo32)); 1467 break; 1468 case SHM_INFO: 1469 CP(u.shm_info, u32.shm_info32, used_ids); 1470 CP(u.shm_info, u32.shm_info32, shm_rss); 1471 CP(u.shm_info, u32.shm_info32, shm_tot); 1472 CP(u.shm_info, u32.shm_info32, shm_swp); 1473 CP(u.shm_info, u32.shm_info32, swap_attempts); 1474 CP(u.shm_info, u32.shm_info32, swap_successes); 1475 error = copyout(&u32.shm_info32, uap->buf, 1476 sizeof(u32.shm_info32)); 1477 break; 1478 case SHM_STAT: 1479 case IPC_STAT: 1480 memset(&u32.shmid_ds32, 0, sizeof(u32.shmid_ds32)); 1481 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm, 1482 &u32.shmid_ds32.shm_perm); 1483 if (u.shmid_ds.shm_segsz > INT32_MAX) 1484 u32.shmid_ds32.shm_segsz = INT32_MAX; 1485 else 1486 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1487 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1488 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1489 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1490 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1491 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1492 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1493 u32.shmid_ds32.shm_internal = 0; 1494 error = copyout(&u32.shmid_ds32, uap->buf, 1495 sizeof(u32.shmid_ds32)); 1496 break; 1497 } 1498 1499 done: 1500 if (error) { 1501 /* Invalidate the return value */ 1502 td->td_retval[0] = -1; 1503 } 1504 return (error); 1505 } 1506 #endif 1507 1508 int 1509 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap) 1510 { 1511 int error; 1512 union { 1513 struct shmid_ds shmid_ds; 1514 struct shm_info shm_info; 1515 struct shminfo shminfo; 1516 } u; 1517 union { 1518 struct shmid_ds32 shmid_ds32; 1519 struct shm_info32 shm_info32; 1520 struct shminfo32 shminfo32; 1521 } u32; 1522 size_t sz; 1523 1524 if (uap->cmd == IPC_SET) { 1525 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1526 sizeof(u32.shmid_ds32)))) 1527 goto done; 1528 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm, 1529 &u.shmid_ds.shm_perm); 1530 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1531 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1532 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1533 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1534 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1535 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1536 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1537 } 1538 1539 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1540 if (error) 1541 goto done; 1542 1543 /* Cases in which we need to copyout */ 1544 switch (uap->cmd) { 1545 case IPC_INFO: 1546 CP(u.shminfo, u32.shminfo32, shmmax); 1547 CP(u.shminfo, u32.shminfo32, shmmin); 1548 CP(u.shminfo, u32.shminfo32, shmmni); 1549 CP(u.shminfo, u32.shminfo32, shmseg); 1550 CP(u.shminfo, u32.shminfo32, shmall); 1551 error = copyout(&u32.shminfo32, uap->buf, 1552 sizeof(u32.shminfo32)); 1553 break; 1554 case SHM_INFO: 1555 CP(u.shm_info, u32.shm_info32, used_ids); 1556 CP(u.shm_info, u32.shm_info32, shm_rss); 1557 CP(u.shm_info, u32.shm_info32, shm_tot); 1558 CP(u.shm_info, u32.shm_info32, shm_swp); 1559 CP(u.shm_info, u32.shm_info32, swap_attempts); 1560 CP(u.shm_info, u32.shm_info32, swap_successes); 1561 error = copyout(&u32.shm_info32, uap->buf, 1562 sizeof(u32.shm_info32)); 1563 break; 1564 case SHM_STAT: 1565 case IPC_STAT: 1566 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm, 1567 &u32.shmid_ds32.shm_perm); 1568 if (u.shmid_ds.shm_segsz > INT32_MAX) 1569 u32.shmid_ds32.shm_segsz = INT32_MAX; 1570 else 1571 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1572 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1573 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1574 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1575 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1576 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1577 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1578 error = copyout(&u32.shmid_ds32, uap->buf, 1579 sizeof(u32.shmid_ds32)); 1580 break; 1581 } 1582 1583 done: 1584 if (error) { 1585 /* Invalidate the return value */ 1586 td->td_retval[0] = -1; 1587 } 1588 return (error); 1589 } 1590 #endif 1591 1592 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1593 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1594 1595 #ifndef _SYS_SYSPROTO_H_ 1596 struct freebsd7_shmctl_args { 1597 int shmid; 1598 int cmd; 1599 struct shmid_ds_old *buf; 1600 }; 1601 #endif 1602 int 1603 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap) 1604 { 1605 int error; 1606 struct shmid_ds_old old; 1607 struct shmid_ds buf; 1608 size_t bufsz; 1609 1610 /* 1611 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 1612 * Linux binaries. If we see the call come through the FreeBSD ABI, 1613 * return an error back to the user since we do not to support this. 1614 */ 1615 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 1616 uap->cmd == SHM_STAT) 1617 return (EINVAL); 1618 1619 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 1620 if (uap->cmd == IPC_SET) { 1621 if ((error = copyin(uap->buf, &old, sizeof(old)))) 1622 goto done; 1623 ipcperm_old2new(&old.shm_perm, &buf.shm_perm); 1624 CP(old, buf, shm_segsz); 1625 CP(old, buf, shm_lpid); 1626 CP(old, buf, shm_cpid); 1627 CP(old, buf, shm_nattch); 1628 CP(old, buf, shm_atime); 1629 CP(old, buf, shm_dtime); 1630 CP(old, buf, shm_ctime); 1631 } 1632 1633 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 1634 if (error) 1635 goto done; 1636 1637 /* Cases in which we need to copyout */ 1638 switch (uap->cmd) { 1639 case IPC_STAT: 1640 memset(&old, 0, sizeof(old)); 1641 ipcperm_new2old(&buf.shm_perm, &old.shm_perm); 1642 if (buf.shm_segsz > INT_MAX) 1643 old.shm_segsz = INT_MAX; 1644 else 1645 CP(buf, old, shm_segsz); 1646 CP(buf, old, shm_lpid); 1647 CP(buf, old, shm_cpid); 1648 if (buf.shm_nattch > SHRT_MAX) 1649 old.shm_nattch = SHRT_MAX; 1650 else 1651 CP(buf, old, shm_nattch); 1652 CP(buf, old, shm_atime); 1653 CP(buf, old, shm_dtime); 1654 CP(buf, old, shm_ctime); 1655 old.shm_internal = NULL; 1656 error = copyout(&old, uap->buf, sizeof(old)); 1657 break; 1658 } 1659 1660 done: 1661 if (error) { 1662 /* Invalidate the return value */ 1663 td->td_retval[0] = -1; 1664 } 1665 return (error); 1666 } 1667 1668 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || 1669 COMPAT_FREEBSD7 */ 1670 1671 static int 1672 sysvshm_modload(struct module *module, int cmd, void *arg) 1673 { 1674 int error = 0; 1675 1676 switch (cmd) { 1677 case MOD_LOAD: 1678 error = shminit(); 1679 if (error != 0) 1680 shmunload(); 1681 break; 1682 case MOD_UNLOAD: 1683 error = shmunload(); 1684 break; 1685 case MOD_SHUTDOWN: 1686 break; 1687 default: 1688 error = EINVAL; 1689 break; 1690 } 1691 return (error); 1692 } 1693 1694 static moduledata_t sysvshm_mod = { 1695 "sysvshm", 1696 &sysvshm_modload, 1697 NULL 1698 }; 1699 1700 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST); 1701 MODULE_VERSION(sysvshm, 1); 1702