1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause AND BSD-2-Clause-FreeBSD 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 __FBSDID("$FreeBSD$"); 73 74 #include "opt_sysvipc.h" 75 76 #include <sys/param.h> 77 #include <sys/systm.h> 78 #include <sys/kernel.h> 79 #include <sys/limits.h> 80 #include <sys/lock.h> 81 #include <sys/sysctl.h> 82 #include <sys/shm.h> 83 #include <sys/proc.h> 84 #include <sys/malloc.h> 85 #include <sys/mman.h> 86 #include <sys/module.h> 87 #include <sys/mutex.h> 88 #include <sys/racct.h> 89 #include <sys/resourcevar.h> 90 #include <sys/rwlock.h> 91 #include <sys/stat.h> 92 #include <sys/syscall.h> 93 #include <sys/syscallsubr.h> 94 #include <sys/sysent.h> 95 #include <sys/sysproto.h> 96 #include <sys/jail.h> 97 98 #include <security/audit/audit.h> 99 #include <security/mac/mac_framework.h> 100 101 #include <vm/vm.h> 102 #include <vm/vm_param.h> 103 #include <vm/pmap.h> 104 #include <vm/vm_object.h> 105 #include <vm/vm_map.h> 106 #include <vm/vm_page.h> 107 #include <vm/vm_pager.h> 108 109 FEATURE(sysv_shm, "System V shared memory segments support"); 110 111 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments"); 112 113 static int shmget_allocate_segment(struct thread *td, 114 struct shmget_args *uap, int mode); 115 static int shmget_existing(struct thread *td, struct shmget_args *uap, 116 int mode, int segnum); 117 118 #define SHMSEG_FREE 0x0200 119 #define SHMSEG_REMOVED 0x0400 120 #define SHMSEG_ALLOCATED 0x0800 121 122 static int shm_last_free, shm_nused, shmalloced; 123 vm_size_t shm_committed; 124 static struct shmid_kernel *shmsegs; 125 static unsigned shm_prison_slot; 126 127 struct shmmap_state { 128 vm_offset_t va; 129 int shmid; 130 }; 131 132 static void shm_deallocate_segment(struct shmid_kernel *); 133 static int shm_find_segment_by_key(struct prison *, key_t); 134 static struct shmid_kernel *shm_find_segment(struct prison *, int, bool); 135 static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *); 136 static void shmrealloc(void); 137 static int shminit(void); 138 static int sysvshm_modload(struct module *, int, void *); 139 static int shmunload(void); 140 #ifndef SYSVSHM 141 static void shmexit_myhook(struct vmspace *vm); 142 static void shmfork_myhook(struct proc *p1, struct proc *p2); 143 #endif 144 static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS); 145 static void shm_remove(struct shmid_kernel *, int); 146 static struct prison *shm_find_prison(struct ucred *); 147 static int shm_prison_cansee(struct prison *, struct shmid_kernel *); 148 static int shm_prison_check(void *, void *); 149 static int shm_prison_set(void *, void *); 150 static int shm_prison_get(void *, void *); 151 static int shm_prison_remove(void *, void *); 152 static void shm_prison_cleanup(struct prison *); 153 154 /* 155 * Tuneable values. 156 */ 157 #ifndef SHMMAXPGS 158 #define SHMMAXPGS 131072 /* Note: sysv shared memory is swap backed. */ 159 #endif 160 #ifndef SHMMAX 161 #define SHMMAX (SHMMAXPGS*PAGE_SIZE) 162 #endif 163 #ifndef SHMMIN 164 #define SHMMIN 1 165 #endif 166 #ifndef SHMMNI 167 #define SHMMNI 192 168 #endif 169 #ifndef SHMSEG 170 #define SHMSEG 128 171 #endif 172 #ifndef SHMALL 173 #define SHMALL (SHMMAXPGS) 174 #endif 175 176 struct shminfo shminfo = { 177 .shmmax = SHMMAX, 178 .shmmin = SHMMIN, 179 .shmmni = SHMMNI, 180 .shmseg = SHMSEG, 181 .shmall = SHMALL 182 }; 183 184 static int shm_use_phys; 185 static int shm_allow_removed = 1; 186 187 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RWTUN, &shminfo.shmmax, 0, 188 "Maximum shared memory segment size"); 189 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RWTUN, &shminfo.shmmin, 0, 190 "Minimum shared memory segment size"); 191 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0, 192 "Number of shared memory identifiers"); 193 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0, 194 "Number of segments per process"); 195 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RWTUN, &shminfo.shmall, 0, 196 "Maximum number of pages available for shared memory"); 197 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RWTUN, 198 &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core"); 199 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RWTUN, 200 &shm_allow_removed, 0, 201 "Enable/Disable attachment to attached segments marked for removal"); 202 SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD | 203 CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "", 204 "Array of struct shmid_kernel for each potential shared memory segment"); 205 206 static struct sx sysvshmsx; 207 #define SYSVSHM_LOCK() sx_xlock(&sysvshmsx) 208 #define SYSVSHM_UNLOCK() sx_xunlock(&sysvshmsx) 209 #define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED) 210 211 static int 212 shm_find_segment_by_key(struct prison *pr, key_t key) 213 { 214 int i; 215 216 for (i = 0; i < shmalloced; i++) 217 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) && 218 shmsegs[i].cred != NULL && 219 shmsegs[i].cred->cr_prison == pr && 220 shmsegs[i].u.shm_perm.key == key) 221 return (i); 222 return (-1); 223 } 224 225 /* 226 * Finds segment either by shmid if is_shmid is true, or by segnum if 227 * is_shmid is false. 228 */ 229 static struct shmid_kernel * 230 shm_find_segment(struct prison *rpr, int arg, bool is_shmid) 231 { 232 struct shmid_kernel *shmseg; 233 int segnum; 234 235 segnum = is_shmid ? IPCID_TO_IX(arg) : arg; 236 if (segnum < 0 || segnum >= shmalloced) 237 return (NULL); 238 shmseg = &shmsegs[segnum]; 239 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 240 (!shm_allow_removed && 241 (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) || 242 (is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg)) || 243 shm_prison_cansee(rpr, shmseg) != 0) 244 return (NULL); 245 return (shmseg); 246 } 247 248 static void 249 shm_deallocate_segment(struct shmid_kernel *shmseg) 250 { 251 vm_size_t size; 252 253 SYSVSHM_ASSERT_LOCKED(); 254 255 vm_object_deallocate(shmseg->object); 256 shmseg->object = NULL; 257 size = round_page(shmseg->u.shm_segsz); 258 shm_committed -= btoc(size); 259 shm_nused--; 260 shmseg->u.shm_perm.mode = SHMSEG_FREE; 261 #ifdef MAC 262 mac_sysvshm_cleanup(shmseg); 263 #endif 264 racct_sub_cred(shmseg->cred, RACCT_NSHM, 1); 265 racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size); 266 crfree(shmseg->cred); 267 shmseg->cred = NULL; 268 } 269 270 static int 271 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s) 272 { 273 struct shmid_kernel *shmseg; 274 int segnum, result; 275 vm_size_t size; 276 277 SYSVSHM_ASSERT_LOCKED(); 278 segnum = IPCID_TO_IX(shmmap_s->shmid); 279 KASSERT(segnum >= 0 && segnum < shmalloced, 280 ("segnum %d shmalloced %d", segnum, shmalloced)); 281 282 shmseg = &shmsegs[segnum]; 283 size = round_page(shmseg->u.shm_segsz); 284 result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size); 285 if (result != KERN_SUCCESS) 286 return (EINVAL); 287 shmmap_s->shmid = -1; 288 shmseg->u.shm_dtime = time_second; 289 if (--shmseg->u.shm_nattch == 0 && 290 (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) { 291 shm_deallocate_segment(shmseg); 292 shm_last_free = segnum; 293 } 294 return (0); 295 } 296 297 static void 298 shm_remove(struct shmid_kernel *shmseg, int segnum) 299 { 300 301 shmseg->u.shm_perm.key = IPC_PRIVATE; 302 shmseg->u.shm_perm.mode |= SHMSEG_REMOVED; 303 if (shmseg->u.shm_nattch == 0) { 304 shm_deallocate_segment(shmseg); 305 shm_last_free = segnum; 306 } 307 } 308 309 static struct prison * 310 shm_find_prison(struct ucred *cred) 311 { 312 struct prison *pr, *rpr; 313 314 pr = cred->cr_prison; 315 prison_lock(pr); 316 rpr = osd_jail_get(pr, shm_prison_slot); 317 prison_unlock(pr); 318 return rpr; 319 } 320 321 static int 322 shm_prison_cansee(struct prison *rpr, struct shmid_kernel *shmseg) 323 { 324 325 if (shmseg->cred == NULL || 326 !(rpr == shmseg->cred->cr_prison || 327 prison_ischild(rpr, shmseg->cred->cr_prison))) 328 return (EINVAL); 329 return (0); 330 } 331 332 static int 333 kern_shmdt_locked(struct thread *td, const void *shmaddr) 334 { 335 struct proc *p = td->td_proc; 336 struct shmmap_state *shmmap_s; 337 #ifdef MAC 338 int error; 339 #endif 340 int i; 341 342 SYSVSHM_ASSERT_LOCKED(); 343 if (shm_find_prison(td->td_ucred) == NULL) 344 return (ENOSYS); 345 shmmap_s = p->p_vmspace->vm_shm; 346 if (shmmap_s == NULL) 347 return (EINVAL); 348 AUDIT_ARG_SVIPC_ID(shmmap_s->shmid); 349 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 350 if (shmmap_s->shmid != -1 && 351 shmmap_s->va == (vm_offset_t)shmaddr) { 352 break; 353 } 354 } 355 if (i == shminfo.shmseg) 356 return (EINVAL); 357 #ifdef MAC 358 error = mac_sysvshm_check_shmdt(td->td_ucred, 359 &shmsegs[IPCID_TO_IX(shmmap_s->shmid)]); 360 if (error != 0) 361 return (error); 362 #endif 363 return (shm_delete_mapping(p->p_vmspace, shmmap_s)); 364 } 365 366 #ifndef _SYS_SYSPROTO_H_ 367 struct shmdt_args { 368 const void *shmaddr; 369 }; 370 #endif 371 int 372 sys_shmdt(struct thread *td, struct shmdt_args *uap) 373 { 374 int error; 375 376 SYSVSHM_LOCK(); 377 error = kern_shmdt_locked(td, uap->shmaddr); 378 SYSVSHM_UNLOCK(); 379 return (error); 380 } 381 382 static int 383 kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr, 384 int shmflg) 385 { 386 struct prison *rpr; 387 struct proc *p = td->td_proc; 388 struct shmid_kernel *shmseg; 389 struct shmmap_state *shmmap_s; 390 vm_offset_t attach_va; 391 vm_prot_t prot; 392 vm_size_t size; 393 int cow, error, find_space, i, rv; 394 395 AUDIT_ARG_SVIPC_ID(shmid); 396 AUDIT_ARG_VALUE(shmflg); 397 398 SYSVSHM_ASSERT_LOCKED(); 399 rpr = shm_find_prison(td->td_ucred); 400 if (rpr == NULL) 401 return (ENOSYS); 402 shmmap_s = p->p_vmspace->vm_shm; 403 if (shmmap_s == NULL) { 404 shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state), 405 M_SHM, M_WAITOK); 406 for (i = 0; i < shminfo.shmseg; i++) 407 shmmap_s[i].shmid = -1; 408 KASSERT(p->p_vmspace->vm_shm == NULL, ("raced")); 409 p->p_vmspace->vm_shm = shmmap_s; 410 } 411 shmseg = shm_find_segment(rpr, shmid, true); 412 if (shmseg == NULL) 413 return (EINVAL); 414 error = ipcperm(td, &shmseg->u.shm_perm, 415 (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); 416 if (error != 0) 417 return (error); 418 #ifdef MAC 419 error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg); 420 if (error != 0) 421 return (error); 422 #endif 423 for (i = 0; i < shminfo.shmseg; i++) { 424 if (shmmap_s->shmid == -1) 425 break; 426 shmmap_s++; 427 } 428 if (i >= shminfo.shmseg) 429 return (EMFILE); 430 size = round_page(shmseg->u.shm_segsz); 431 prot = VM_PROT_READ; 432 cow = MAP_INHERIT_SHARE | MAP_PREFAULT_PARTIAL; 433 if ((shmflg & SHM_RDONLY) == 0) 434 prot |= VM_PROT_WRITE; 435 if (shmaddr != NULL) { 436 if ((shmflg & SHM_RND) != 0) 437 attach_va = rounddown2((vm_offset_t)shmaddr, SHMLBA); 438 else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0) 439 attach_va = (vm_offset_t)shmaddr; 440 else 441 return (EINVAL); 442 if ((shmflg & SHM_REMAP) != 0) 443 cow |= MAP_REMAP; 444 find_space = VMFS_NO_SPACE; 445 } else { 446 /* 447 * This is just a hint to vm_map_find() about where to 448 * put it. 449 */ 450 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 451 lim_max(td, RLIMIT_DATA)); 452 find_space = VMFS_OPTIMAL_SPACE; 453 } 454 455 vm_object_reference(shmseg->object); 456 rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object, 0, &attach_va, 457 size, 0, find_space, prot, prot, cow); 458 if (rv != KERN_SUCCESS) { 459 vm_object_deallocate(shmseg->object); 460 return (ENOMEM); 461 } 462 463 shmmap_s->va = attach_va; 464 shmmap_s->shmid = shmid; 465 shmseg->u.shm_lpid = p->p_pid; 466 shmseg->u.shm_atime = time_second; 467 shmseg->u.shm_nattch++; 468 td->td_retval[0] = attach_va; 469 return (error); 470 } 471 472 int 473 kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg) 474 { 475 int error; 476 477 SYSVSHM_LOCK(); 478 error = kern_shmat_locked(td, shmid, shmaddr, shmflg); 479 SYSVSHM_UNLOCK(); 480 return (error); 481 } 482 483 #ifndef _SYS_SYSPROTO_H_ 484 struct shmat_args { 485 int shmid; 486 const void *shmaddr; 487 int shmflg; 488 }; 489 #endif 490 int 491 sys_shmat(struct thread *td, struct shmat_args *uap) 492 { 493 494 return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg)); 495 } 496 497 static int 498 kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf, 499 size_t *bufsz) 500 { 501 struct prison *rpr; 502 struct shmid_kernel *shmseg; 503 struct shmid_ds *shmidp; 504 struct shm_info shm_info; 505 int error; 506 507 SYSVSHM_ASSERT_LOCKED(); 508 509 rpr = shm_find_prison(td->td_ucred); 510 if (rpr == NULL) 511 return (ENOSYS); 512 513 AUDIT_ARG_SVIPC_ID(shmid); 514 AUDIT_ARG_SVIPC_CMD(cmd); 515 516 switch (cmd) { 517 /* 518 * It is possible that kern_shmctl is being called from the Linux ABI 519 * layer, in which case, we will need to implement IPC_INFO. It should 520 * be noted that other shmctl calls will be funneled through here for 521 * Linix binaries as well. 522 * 523 * NB: The Linux ABI layer will convert this data to structure(s) more 524 * consistent with the Linux ABI. 525 */ 526 case IPC_INFO: 527 memcpy(buf, &shminfo, sizeof(shminfo)); 528 if (bufsz) 529 *bufsz = sizeof(shminfo); 530 td->td_retval[0] = shmalloced; 531 return (0); 532 case SHM_INFO: { 533 shm_info.used_ids = shm_nused; 534 shm_info.shm_rss = 0; /*XXX where to get from ? */ 535 shm_info.shm_tot = 0; /*XXX where to get from ? */ 536 shm_info.shm_swp = 0; /*XXX where to get from ? */ 537 shm_info.swap_attempts = 0; /*XXX where to get from ? */ 538 shm_info.swap_successes = 0; /*XXX where to get from ? */ 539 memcpy(buf, &shm_info, sizeof(shm_info)); 540 if (bufsz != NULL) 541 *bufsz = sizeof(shm_info); 542 td->td_retval[0] = shmalloced; 543 return (0); 544 } 545 } 546 shmseg = shm_find_segment(rpr, shmid, cmd != SHM_STAT); 547 if (shmseg == NULL) 548 return (EINVAL); 549 #ifdef MAC 550 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd); 551 if (error != 0) 552 return (error); 553 #endif 554 switch (cmd) { 555 case SHM_STAT: 556 case IPC_STAT: 557 shmidp = (struct shmid_ds *)buf; 558 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 559 if (error != 0) 560 return (error); 561 memcpy(shmidp, &shmseg->u, sizeof(struct shmid_ds)); 562 if (td->td_ucred->cr_prison != shmseg->cred->cr_prison) 563 shmidp->shm_perm.key = IPC_PRIVATE; 564 if (bufsz != NULL) 565 *bufsz = sizeof(struct shmid_ds); 566 if (cmd == SHM_STAT) { 567 td->td_retval[0] = IXSEQ_TO_IPCID(shmid, 568 shmseg->u.shm_perm); 569 } 570 break; 571 case IPC_SET: 572 shmidp = (struct shmid_ds *)buf; 573 AUDIT_ARG_SVIPC_PERM(&shmidp->shm_perm); 574 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); 575 if (error != 0) 576 return (error); 577 shmseg->u.shm_perm.uid = shmidp->shm_perm.uid; 578 shmseg->u.shm_perm.gid = shmidp->shm_perm.gid; 579 shmseg->u.shm_perm.mode = 580 (shmseg->u.shm_perm.mode & ~ACCESSPERMS) | 581 (shmidp->shm_perm.mode & ACCESSPERMS); 582 shmseg->u.shm_ctime = time_second; 583 break; 584 case IPC_RMID: 585 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); 586 if (error != 0) 587 return (error); 588 shm_remove(shmseg, IPCID_TO_IX(shmid)); 589 break; 590 #if 0 591 case SHM_LOCK: 592 case SHM_UNLOCK: 593 #endif 594 default: 595 error = EINVAL; 596 break; 597 } 598 return (error); 599 } 600 601 int 602 kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz) 603 { 604 int error; 605 606 SYSVSHM_LOCK(); 607 error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz); 608 SYSVSHM_UNLOCK(); 609 return (error); 610 } 611 612 613 #ifndef _SYS_SYSPROTO_H_ 614 struct shmctl_args { 615 int shmid; 616 int cmd; 617 struct shmid_ds *buf; 618 }; 619 #endif 620 int 621 sys_shmctl(struct thread *td, struct shmctl_args *uap) 622 { 623 int error; 624 struct shmid_ds buf; 625 size_t bufsz; 626 627 /* 628 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 629 * Linux binaries. If we see the call come through the FreeBSD ABI, 630 * return an error back to the user since we do not to support this. 631 */ 632 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 633 uap->cmd == SHM_STAT) 634 return (EINVAL); 635 636 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 637 if (uap->cmd == IPC_SET) { 638 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds)))) 639 goto done; 640 } 641 642 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 643 if (error) 644 goto done; 645 646 /* Cases in which we need to copyout */ 647 switch (uap->cmd) { 648 case IPC_STAT: 649 error = copyout(&buf, uap->buf, bufsz); 650 break; 651 } 652 653 done: 654 if (error) { 655 /* Invalidate the return value */ 656 td->td_retval[0] = -1; 657 } 658 return (error); 659 } 660 661 662 static int 663 shmget_existing(struct thread *td, struct shmget_args *uap, int mode, 664 int segnum) 665 { 666 struct shmid_kernel *shmseg; 667 #ifdef MAC 668 int error; 669 #endif 670 671 SYSVSHM_ASSERT_LOCKED(); 672 KASSERT(segnum >= 0 && segnum < shmalloced, 673 ("segnum %d shmalloced %d", segnum, shmalloced)); 674 shmseg = &shmsegs[segnum]; 675 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) 676 return (EEXIST); 677 #ifdef MAC 678 error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg); 679 if (error != 0) 680 return (error); 681 #endif 682 if (uap->size != 0 && uap->size > shmseg->u.shm_segsz) 683 return (EINVAL); 684 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 685 return (0); 686 } 687 688 static int 689 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode) 690 { 691 struct ucred *cred = td->td_ucred; 692 struct shmid_kernel *shmseg; 693 vm_object_t shm_object; 694 int i, segnum; 695 size_t size; 696 697 SYSVSHM_ASSERT_LOCKED(); 698 699 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) 700 return (EINVAL); 701 if (shm_nused >= shminfo.shmmni) /* Any shmids left? */ 702 return (ENOSPC); 703 size = round_page(uap->size); 704 if (shm_committed + btoc(size) > shminfo.shmall) 705 return (ENOMEM); 706 if (shm_last_free < 0) { 707 shmrealloc(); /* Maybe expand the shmsegs[] array. */ 708 for (i = 0; i < shmalloced; i++) 709 if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE) 710 break; 711 if (i == shmalloced) 712 return (ENOSPC); 713 segnum = i; 714 } else { 715 segnum = shm_last_free; 716 shm_last_free = -1; 717 } 718 KASSERT(segnum >= 0 && segnum < shmalloced, 719 ("segnum %d shmalloced %d", segnum, shmalloced)); 720 shmseg = &shmsegs[segnum]; 721 #ifdef RACCT 722 if (racct_enable) { 723 PROC_LOCK(td->td_proc); 724 if (racct_add(td->td_proc, RACCT_NSHM, 1)) { 725 PROC_UNLOCK(td->td_proc); 726 return (ENOSPC); 727 } 728 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) { 729 racct_sub(td->td_proc, RACCT_NSHM, 1); 730 PROC_UNLOCK(td->td_proc); 731 return (ENOMEM); 732 } 733 PROC_UNLOCK(td->td_proc); 734 } 735 #endif 736 737 /* 738 * We make sure that we have allocated a pager before we need 739 * to. 740 */ 741 shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP, 742 0, size, VM_PROT_DEFAULT, 0, cred); 743 if (shm_object == NULL) { 744 #ifdef RACCT 745 if (racct_enable) { 746 PROC_LOCK(td->td_proc); 747 racct_sub(td->td_proc, RACCT_NSHM, 1); 748 racct_sub(td->td_proc, RACCT_SHMSIZE, size); 749 PROC_UNLOCK(td->td_proc); 750 } 751 #endif 752 return (ENOMEM); 753 } 754 shm_object->pg_color = 0; 755 VM_OBJECT_WLOCK(shm_object); 756 vm_object_clear_flag(shm_object, OBJ_ONEMAPPING); 757 vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT); 758 VM_OBJECT_WUNLOCK(shm_object); 759 760 shmseg->object = shm_object; 761 shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid; 762 shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid; 763 shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; 764 shmseg->u.shm_perm.key = uap->key; 765 shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff; 766 shmseg->cred = crhold(cred); 767 shmseg->u.shm_segsz = uap->size; 768 shmseg->u.shm_cpid = td->td_proc->p_pid; 769 shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0; 770 shmseg->u.shm_atime = shmseg->u.shm_dtime = 0; 771 #ifdef MAC 772 mac_sysvshm_create(cred, shmseg); 773 #endif 774 shmseg->u.shm_ctime = time_second; 775 shm_committed += btoc(size); 776 shm_nused++; 777 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 778 779 return (0); 780 } 781 782 #ifndef _SYS_SYSPROTO_H_ 783 struct shmget_args { 784 key_t key; 785 size_t size; 786 int shmflg; 787 }; 788 #endif 789 int 790 sys_shmget(struct thread *td, struct shmget_args *uap) 791 { 792 int segnum, mode; 793 int error; 794 795 if (shm_find_prison(td->td_ucred) == NULL) 796 return (ENOSYS); 797 mode = uap->shmflg & ACCESSPERMS; 798 SYSVSHM_LOCK(); 799 if (uap->key == IPC_PRIVATE) { 800 error = shmget_allocate_segment(td, uap, mode); 801 } else { 802 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison, 803 uap->key); 804 if (segnum >= 0) 805 error = shmget_existing(td, uap, mode, segnum); 806 else if ((uap->shmflg & IPC_CREAT) == 0) 807 error = ENOENT; 808 else 809 error = shmget_allocate_segment(td, uap, mode); 810 } 811 SYSVSHM_UNLOCK(); 812 return (error); 813 } 814 815 #ifdef SYSVSHM 816 void 817 shmfork(struct proc *p1, struct proc *p2) 818 #else 819 static void 820 shmfork_myhook(struct proc *p1, struct proc *p2) 821 #endif 822 { 823 struct shmmap_state *shmmap_s; 824 size_t size; 825 int i; 826 827 SYSVSHM_LOCK(); 828 size = shminfo.shmseg * sizeof(struct shmmap_state); 829 shmmap_s = malloc(size, M_SHM, M_WAITOK); 830 bcopy(p1->p_vmspace->vm_shm, shmmap_s, size); 831 p2->p_vmspace->vm_shm = shmmap_s; 832 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 833 if (shmmap_s->shmid != -1) { 834 KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 && 835 IPCID_TO_IX(shmmap_s->shmid) < shmalloced, 836 ("segnum %d shmalloced %d", 837 IPCID_TO_IX(shmmap_s->shmid), shmalloced)); 838 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++; 839 } 840 } 841 SYSVSHM_UNLOCK(); 842 } 843 844 #ifdef SYSVSHM 845 void 846 shmexit(struct vmspace *vm) 847 #else 848 static void 849 shmexit_myhook(struct vmspace *vm) 850 #endif 851 { 852 struct shmmap_state *base, *shm; 853 int i; 854 855 base = vm->vm_shm; 856 if (base != NULL) { 857 vm->vm_shm = NULL; 858 SYSVSHM_LOCK(); 859 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) { 860 if (shm->shmid != -1) 861 shm_delete_mapping(vm, shm); 862 } 863 SYSVSHM_UNLOCK(); 864 free(base, M_SHM); 865 } 866 } 867 868 static void 869 shmrealloc(void) 870 { 871 struct shmid_kernel *newsegs; 872 int i; 873 874 SYSVSHM_ASSERT_LOCKED(); 875 876 if (shmalloced >= shminfo.shmmni) 877 return; 878 879 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, 880 M_WAITOK | M_ZERO); 881 for (i = 0; i < shmalloced; i++) 882 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 883 for (; i < shminfo.shmmni; i++) { 884 newsegs[i].u.shm_perm.mode = SHMSEG_FREE; 885 newsegs[i].u.shm_perm.seq = 0; 886 #ifdef MAC 887 mac_sysvshm_init(&newsegs[i]); 888 #endif 889 } 890 free(shmsegs, M_SHM); 891 shmsegs = newsegs; 892 shmalloced = shminfo.shmmni; 893 } 894 895 static struct syscall_helper_data shm_syscalls[] = { 896 SYSCALL_INIT_HELPER(shmat), 897 SYSCALL_INIT_HELPER(shmctl), 898 SYSCALL_INIT_HELPER(shmdt), 899 SYSCALL_INIT_HELPER(shmget), 900 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 901 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 902 SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl), 903 #endif 904 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 905 SYSCALL_INIT_HELPER(shmsys), 906 #endif 907 SYSCALL_INIT_LAST 908 }; 909 910 #ifdef COMPAT_FREEBSD32 911 #include <compat/freebsd32/freebsd32.h> 912 #include <compat/freebsd32/freebsd32_ipc.h> 913 #include <compat/freebsd32/freebsd32_proto.h> 914 #include <compat/freebsd32/freebsd32_signal.h> 915 #include <compat/freebsd32/freebsd32_syscall.h> 916 #include <compat/freebsd32/freebsd32_util.h> 917 918 static struct syscall_helper_data shm32_syscalls[] = { 919 SYSCALL32_INIT_HELPER_COMPAT(shmat), 920 SYSCALL32_INIT_HELPER_COMPAT(shmdt), 921 SYSCALL32_INIT_HELPER_COMPAT(shmget), 922 SYSCALL32_INIT_HELPER(freebsd32_shmsys), 923 SYSCALL32_INIT_HELPER(freebsd32_shmctl), 924 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 925 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 926 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl), 927 #endif 928 SYSCALL_INIT_LAST 929 }; 930 #endif 931 932 static int 933 shminit(void) 934 { 935 struct prison *pr; 936 void **rsv; 937 int i, error; 938 osd_method_t methods[PR_MAXMETHOD] = { 939 [PR_METHOD_CHECK] = shm_prison_check, 940 [PR_METHOD_SET] = shm_prison_set, 941 [PR_METHOD_GET] = shm_prison_get, 942 [PR_METHOD_REMOVE] = shm_prison_remove, 943 }; 944 945 #ifndef BURN_BRIDGES 946 if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0) 947 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n"); 948 #endif 949 if (shminfo.shmmax == SHMMAX) { 950 /* Initialize shmmax dealing with possible overflow. */ 951 for (i = PAGE_SIZE; i != 0; i--) { 952 shminfo.shmmax = shminfo.shmall * i; 953 if ((shminfo.shmmax / shminfo.shmall) == (u_long)i) 954 break; 955 } 956 } 957 shmalloced = shminfo.shmmni; 958 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, 959 M_WAITOK|M_ZERO); 960 for (i = 0; i < shmalloced; i++) { 961 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; 962 shmsegs[i].u.shm_perm.seq = 0; 963 #ifdef MAC 964 mac_sysvshm_init(&shmsegs[i]); 965 #endif 966 } 967 shm_last_free = 0; 968 shm_nused = 0; 969 shm_committed = 0; 970 sx_init(&sysvshmsx, "sysvshmsx"); 971 #ifndef SYSVSHM 972 shmexit_hook = &shmexit_myhook; 973 shmfork_hook = &shmfork_myhook; 974 #endif 975 976 /* Set current prisons according to their allow.sysvipc. */ 977 shm_prison_slot = osd_jail_register(NULL, methods); 978 rsv = osd_reserve(shm_prison_slot); 979 prison_lock(&prison0); 980 (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0); 981 prison_unlock(&prison0); 982 rsv = NULL; 983 sx_slock(&allprison_lock); 984 TAILQ_FOREACH(pr, &allprison, pr_list) { 985 if (rsv == NULL) 986 rsv = osd_reserve(shm_prison_slot); 987 prison_lock(pr); 988 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) { 989 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 990 &prison0); 991 rsv = NULL; 992 } 993 prison_unlock(pr); 994 } 995 if (rsv != NULL) 996 osd_free_reserved(rsv); 997 sx_sunlock(&allprison_lock); 998 999 error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD); 1000 if (error != 0) 1001 return (error); 1002 #ifdef COMPAT_FREEBSD32 1003 error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD); 1004 if (error != 0) 1005 return (error); 1006 #endif 1007 return (0); 1008 } 1009 1010 static int 1011 shmunload(void) 1012 { 1013 int i; 1014 1015 if (shm_nused > 0) 1016 return (EBUSY); 1017 1018 #ifdef COMPAT_FREEBSD32 1019 syscall32_helper_unregister(shm32_syscalls); 1020 #endif 1021 syscall_helper_unregister(shm_syscalls); 1022 if (shm_prison_slot != 0) 1023 osd_jail_deregister(shm_prison_slot); 1024 1025 for (i = 0; i < shmalloced; i++) { 1026 #ifdef MAC 1027 mac_sysvshm_destroy(&shmsegs[i]); 1028 #endif 1029 /* 1030 * Objects might be still mapped into the processes 1031 * address spaces. Actual free would happen on the 1032 * last mapping destruction. 1033 */ 1034 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE) 1035 vm_object_deallocate(shmsegs[i].object); 1036 } 1037 free(shmsegs, M_SHM); 1038 #ifndef SYSVSHM 1039 shmexit_hook = NULL; 1040 shmfork_hook = NULL; 1041 #endif 1042 sx_destroy(&sysvshmsx); 1043 return (0); 1044 } 1045 1046 static int 1047 sysctl_shmsegs(SYSCTL_HANDLER_ARGS) 1048 { 1049 struct shmid_kernel tshmseg; 1050 #ifdef COMPAT_FREEBSD32 1051 struct shmid_kernel32 tshmseg32; 1052 #endif 1053 struct prison *pr, *rpr; 1054 void *outaddr; 1055 size_t outsize; 1056 int error, i; 1057 1058 SYSVSHM_LOCK(); 1059 pr = req->td->td_ucred->cr_prison; 1060 rpr = shm_find_prison(req->td->td_ucred); 1061 error = 0; 1062 for (i = 0; i < shmalloced; i++) { 1063 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 1064 rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) { 1065 bzero(&tshmseg, sizeof(tshmseg)); 1066 tshmseg.u.shm_perm.mode = SHMSEG_FREE; 1067 } else { 1068 tshmseg = shmsegs[i]; 1069 if (tshmseg.cred->cr_prison != pr) 1070 tshmseg.u.shm_perm.key = IPC_PRIVATE; 1071 } 1072 #ifdef COMPAT_FREEBSD32 1073 if (SV_CURPROC_FLAG(SV_ILP32)) { 1074 bzero(&tshmseg32, sizeof(tshmseg32)); 1075 freebsd32_ipcperm_out(&tshmseg.u.shm_perm, 1076 &tshmseg32.u.shm_perm); 1077 CP(tshmseg, tshmseg32, u.shm_segsz); 1078 CP(tshmseg, tshmseg32, u.shm_lpid); 1079 CP(tshmseg, tshmseg32, u.shm_cpid); 1080 CP(tshmseg, tshmseg32, u.shm_nattch); 1081 CP(tshmseg, tshmseg32, u.shm_atime); 1082 CP(tshmseg, tshmseg32, u.shm_dtime); 1083 CP(tshmseg, tshmseg32, u.shm_ctime); 1084 /* Don't copy object, label, or cred */ 1085 outaddr = &tshmseg32; 1086 outsize = sizeof(tshmseg32); 1087 } else 1088 #endif 1089 { 1090 tshmseg.object = NULL; 1091 tshmseg.label = NULL; 1092 tshmseg.cred = NULL; 1093 outaddr = &tshmseg; 1094 outsize = sizeof(tshmseg); 1095 } 1096 error = SYSCTL_OUT(req, outaddr, outsize); 1097 if (error != 0) 1098 break; 1099 } 1100 SYSVSHM_UNLOCK(); 1101 return (error); 1102 } 1103 1104 static int 1105 shm_prison_check(void *obj, void *data) 1106 { 1107 struct prison *pr = obj; 1108 struct prison *prpr; 1109 struct vfsoptlist *opts = data; 1110 int error, jsys; 1111 1112 /* 1113 * sysvshm is a jailsys integer. 1114 * It must be "disable" if the parent jail is disabled. 1115 */ 1116 error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1117 if (error != ENOENT) { 1118 if (error != 0) 1119 return (error); 1120 switch (jsys) { 1121 case JAIL_SYS_DISABLE: 1122 break; 1123 case JAIL_SYS_NEW: 1124 case JAIL_SYS_INHERIT: 1125 prison_lock(pr->pr_parent); 1126 prpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1127 prison_unlock(pr->pr_parent); 1128 if (prpr == NULL) 1129 return (EPERM); 1130 break; 1131 default: 1132 return (EINVAL); 1133 } 1134 } 1135 1136 return (0); 1137 } 1138 1139 static int 1140 shm_prison_set(void *obj, void *data) 1141 { 1142 struct prison *pr = obj; 1143 struct prison *tpr, *orpr, *nrpr, *trpr; 1144 struct vfsoptlist *opts = data; 1145 void *rsv; 1146 int jsys, descend; 1147 1148 /* 1149 * sysvshm controls which jail is the root of the associated segments 1150 * (this jail or same as the parent), or if the feature is available 1151 * at all. 1152 */ 1153 if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT) 1154 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0) 1155 ? JAIL_SYS_INHERIT 1156 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0) 1157 ? JAIL_SYS_DISABLE 1158 : -1; 1159 if (jsys == JAIL_SYS_DISABLE) { 1160 prison_lock(pr); 1161 orpr = osd_jail_get(pr, shm_prison_slot); 1162 if (orpr != NULL) 1163 osd_jail_del(pr, shm_prison_slot); 1164 prison_unlock(pr); 1165 if (orpr != NULL) { 1166 if (orpr == pr) 1167 shm_prison_cleanup(pr); 1168 /* Disable all child jails as well. */ 1169 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1170 prison_lock(tpr); 1171 trpr = osd_jail_get(tpr, shm_prison_slot); 1172 if (trpr != NULL) { 1173 osd_jail_del(tpr, shm_prison_slot); 1174 prison_unlock(tpr); 1175 if (trpr == tpr) 1176 shm_prison_cleanup(tpr); 1177 } else { 1178 prison_unlock(tpr); 1179 descend = 0; 1180 } 1181 } 1182 } 1183 } else if (jsys != -1) { 1184 if (jsys == JAIL_SYS_NEW) 1185 nrpr = pr; 1186 else { 1187 prison_lock(pr->pr_parent); 1188 nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1189 prison_unlock(pr->pr_parent); 1190 } 1191 rsv = osd_reserve(shm_prison_slot); 1192 prison_lock(pr); 1193 orpr = osd_jail_get(pr, shm_prison_slot); 1194 if (orpr != nrpr) 1195 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 1196 nrpr); 1197 else 1198 osd_free_reserved(rsv); 1199 prison_unlock(pr); 1200 if (orpr != nrpr) { 1201 if (orpr == pr) 1202 shm_prison_cleanup(pr); 1203 if (orpr != NULL) { 1204 /* Change child jails matching the old root, */ 1205 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1206 prison_lock(tpr); 1207 trpr = osd_jail_get(tpr, 1208 shm_prison_slot); 1209 if (trpr == orpr) { 1210 (void)osd_jail_set(tpr, 1211 shm_prison_slot, nrpr); 1212 prison_unlock(tpr); 1213 if (trpr == tpr) 1214 shm_prison_cleanup(tpr); 1215 } else { 1216 prison_unlock(tpr); 1217 descend = 0; 1218 } 1219 } 1220 } 1221 } 1222 } 1223 1224 return (0); 1225 } 1226 1227 static int 1228 shm_prison_get(void *obj, void *data) 1229 { 1230 struct prison *pr = obj; 1231 struct prison *rpr; 1232 struct vfsoptlist *opts = data; 1233 int error, jsys; 1234 1235 /* Set sysvshm based on the jail's root prison. */ 1236 prison_lock(pr); 1237 rpr = osd_jail_get(pr, shm_prison_slot); 1238 prison_unlock(pr); 1239 jsys = rpr == NULL ? JAIL_SYS_DISABLE 1240 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT; 1241 error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1242 if (error == ENOENT) 1243 error = 0; 1244 return (error); 1245 } 1246 1247 static int 1248 shm_prison_remove(void *obj, void *data __unused) 1249 { 1250 struct prison *pr = obj; 1251 struct prison *rpr; 1252 1253 SYSVSHM_LOCK(); 1254 prison_lock(pr); 1255 rpr = osd_jail_get(pr, shm_prison_slot); 1256 prison_unlock(pr); 1257 if (rpr == pr) 1258 shm_prison_cleanup(pr); 1259 SYSVSHM_UNLOCK(); 1260 return (0); 1261 } 1262 1263 static void 1264 shm_prison_cleanup(struct prison *pr) 1265 { 1266 struct shmid_kernel *shmseg; 1267 int i; 1268 1269 /* Remove any segments that belong to this jail. */ 1270 for (i = 0; i < shmalloced; i++) { 1271 shmseg = &shmsegs[i]; 1272 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) && 1273 shmseg->cred != NULL && shmseg->cred->cr_prison == pr) { 1274 shm_remove(shmseg, i); 1275 } 1276 } 1277 } 1278 1279 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory"); 1280 1281 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 1282 struct oshmid_ds { 1283 struct ipc_perm_old shm_perm; /* operation perms */ 1284 int shm_segsz; /* size of segment (bytes) */ 1285 u_short shm_cpid; /* pid, creator */ 1286 u_short shm_lpid; /* pid, last operation */ 1287 short shm_nattch; /* no. of current attaches */ 1288 time_t shm_atime; /* last attach time */ 1289 time_t shm_dtime; /* last detach time */ 1290 time_t shm_ctime; /* last change time */ 1291 void *shm_handle; /* internal handle for shm segment */ 1292 }; 1293 1294 struct oshmctl_args { 1295 int shmid; 1296 int cmd; 1297 struct oshmid_ds *ubuf; 1298 }; 1299 1300 static int 1301 oshmctl(struct thread *td, struct oshmctl_args *uap) 1302 { 1303 #ifdef COMPAT_43 1304 int error = 0; 1305 struct prison *rpr; 1306 struct shmid_kernel *shmseg; 1307 struct oshmid_ds outbuf; 1308 1309 rpr = shm_find_prison(td->td_ucred); 1310 if (rpr == NULL) 1311 return (ENOSYS); 1312 if (uap->cmd != IPC_STAT) { 1313 return (freebsd7_shmctl(td, 1314 (struct freebsd7_shmctl_args *)uap)); 1315 } 1316 SYSVSHM_LOCK(); 1317 shmseg = shm_find_segment(rpr, uap->shmid, true); 1318 if (shmseg == NULL) { 1319 SYSVSHM_UNLOCK(); 1320 return (EINVAL); 1321 } 1322 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 1323 if (error != 0) { 1324 SYSVSHM_UNLOCK(); 1325 return (error); 1326 } 1327 #ifdef MAC 1328 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd); 1329 if (error != 0) { 1330 SYSVSHM_UNLOCK(); 1331 return (error); 1332 } 1333 #endif 1334 ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm); 1335 outbuf.shm_segsz = shmseg->u.shm_segsz; 1336 outbuf.shm_cpid = shmseg->u.shm_cpid; 1337 outbuf.shm_lpid = shmseg->u.shm_lpid; 1338 outbuf.shm_nattch = shmseg->u.shm_nattch; 1339 outbuf.shm_atime = shmseg->u.shm_atime; 1340 outbuf.shm_dtime = shmseg->u.shm_dtime; 1341 outbuf.shm_ctime = shmseg->u.shm_ctime; 1342 outbuf.shm_handle = shmseg->object; 1343 SYSVSHM_UNLOCK(); 1344 return (copyout(&outbuf, uap->ubuf, sizeof(outbuf))); 1345 #else 1346 return (EINVAL); 1347 #endif 1348 } 1349 1350 /* XXX casting to (sy_call_t *) is bogus, as usual. */ 1351 static sy_call_t *shmcalls[] = { 1352 (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl, 1353 (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget, 1354 (sy_call_t *)freebsd7_shmctl 1355 }; 1356 1357 #ifndef _SYS_SYSPROTO_H_ 1358 /* XXX actually varargs. */ 1359 struct shmsys_args { 1360 int which; 1361 int a2; 1362 int a3; 1363 int a4; 1364 }; 1365 #endif 1366 int 1367 sys_shmsys(struct thread *td, struct shmsys_args *uap) 1368 { 1369 1370 AUDIT_ARG_SVIPC_WHICH(uap->which); 1371 if (uap->which < 0 || uap->which >= nitems(shmcalls)) 1372 return (EINVAL); 1373 return ((*shmcalls[uap->which])(td, &uap->a2)); 1374 } 1375 1376 #endif /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */ 1377 1378 #ifdef COMPAT_FREEBSD32 1379 1380 int 1381 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap) 1382 { 1383 1384 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1385 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1386 AUDIT_ARG_SVIPC_WHICH(uap->which); 1387 switch (uap->which) { 1388 case 0: { /* shmat */ 1389 struct shmat_args ap; 1390 1391 ap.shmid = uap->a2; 1392 ap.shmaddr = PTRIN(uap->a3); 1393 ap.shmflg = uap->a4; 1394 return (sysent[SYS_shmat].sy_call(td, &ap)); 1395 } 1396 case 2: { /* shmdt */ 1397 struct shmdt_args ap; 1398 1399 ap.shmaddr = PTRIN(uap->a2); 1400 return (sysent[SYS_shmdt].sy_call(td, &ap)); 1401 } 1402 case 3: { /* shmget */ 1403 struct shmget_args ap; 1404 1405 ap.key = uap->a2; 1406 ap.size = uap->a3; 1407 ap.shmflg = uap->a4; 1408 return (sysent[SYS_shmget].sy_call(td, &ap)); 1409 } 1410 case 4: { /* shmctl */ 1411 struct freebsd7_freebsd32_shmctl_args ap; 1412 1413 ap.shmid = uap->a2; 1414 ap.cmd = uap->a3; 1415 ap.buf = PTRIN(uap->a4); 1416 return (freebsd7_freebsd32_shmctl(td, &ap)); 1417 } 1418 case 1: /* oshmctl */ 1419 default: 1420 return (EINVAL); 1421 } 1422 #else 1423 return (nosys(td, NULL)); 1424 #endif 1425 } 1426 1427 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1428 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1429 int 1430 freebsd7_freebsd32_shmctl(struct thread *td, 1431 struct freebsd7_freebsd32_shmctl_args *uap) 1432 { 1433 int error; 1434 union { 1435 struct shmid_ds shmid_ds; 1436 struct shm_info shm_info; 1437 struct shminfo shminfo; 1438 } u; 1439 union { 1440 struct shmid_ds32_old shmid_ds32; 1441 struct shm_info32 shm_info32; 1442 struct shminfo32 shminfo32; 1443 } u32; 1444 size_t sz; 1445 1446 if (uap->cmd == IPC_SET) { 1447 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1448 sizeof(u32.shmid_ds32)))) 1449 goto done; 1450 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm, 1451 &u.shmid_ds.shm_perm); 1452 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1453 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1454 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1455 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1456 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1457 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1458 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1459 } 1460 1461 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1462 if (error) 1463 goto done; 1464 1465 /* Cases in which we need to copyout */ 1466 switch (uap->cmd) { 1467 case IPC_INFO: 1468 CP(u.shminfo, u32.shminfo32, shmmax); 1469 CP(u.shminfo, u32.shminfo32, shmmin); 1470 CP(u.shminfo, u32.shminfo32, shmmni); 1471 CP(u.shminfo, u32.shminfo32, shmseg); 1472 CP(u.shminfo, u32.shminfo32, shmall); 1473 error = copyout(&u32.shminfo32, uap->buf, 1474 sizeof(u32.shminfo32)); 1475 break; 1476 case SHM_INFO: 1477 CP(u.shm_info, u32.shm_info32, used_ids); 1478 CP(u.shm_info, u32.shm_info32, shm_rss); 1479 CP(u.shm_info, u32.shm_info32, shm_tot); 1480 CP(u.shm_info, u32.shm_info32, shm_swp); 1481 CP(u.shm_info, u32.shm_info32, swap_attempts); 1482 CP(u.shm_info, u32.shm_info32, swap_successes); 1483 error = copyout(&u32.shm_info32, uap->buf, 1484 sizeof(u32.shm_info32)); 1485 break; 1486 case SHM_STAT: 1487 case IPC_STAT: 1488 memset(&u32.shmid_ds32, 0, sizeof(u32.shmid_ds32)); 1489 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm, 1490 &u32.shmid_ds32.shm_perm); 1491 if (u.shmid_ds.shm_segsz > INT32_MAX) 1492 u32.shmid_ds32.shm_segsz = INT32_MAX; 1493 else 1494 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1495 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1496 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1497 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1498 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1499 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1500 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1501 u32.shmid_ds32.shm_internal = 0; 1502 error = copyout(&u32.shmid_ds32, uap->buf, 1503 sizeof(u32.shmid_ds32)); 1504 break; 1505 } 1506 1507 done: 1508 if (error) { 1509 /* Invalidate the return value */ 1510 td->td_retval[0] = -1; 1511 } 1512 return (error); 1513 } 1514 #endif 1515 1516 int 1517 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap) 1518 { 1519 int error; 1520 union { 1521 struct shmid_ds shmid_ds; 1522 struct shm_info shm_info; 1523 struct shminfo shminfo; 1524 } u; 1525 union { 1526 struct shmid_ds32 shmid_ds32; 1527 struct shm_info32 shm_info32; 1528 struct shminfo32 shminfo32; 1529 } u32; 1530 size_t sz; 1531 1532 if (uap->cmd == IPC_SET) { 1533 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1534 sizeof(u32.shmid_ds32)))) 1535 goto done; 1536 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm, 1537 &u.shmid_ds.shm_perm); 1538 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1539 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1540 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1541 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1542 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1543 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1544 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1545 } 1546 1547 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1548 if (error) 1549 goto done; 1550 1551 /* Cases in which we need to copyout */ 1552 switch (uap->cmd) { 1553 case IPC_INFO: 1554 CP(u.shminfo, u32.shminfo32, shmmax); 1555 CP(u.shminfo, u32.shminfo32, shmmin); 1556 CP(u.shminfo, u32.shminfo32, shmmni); 1557 CP(u.shminfo, u32.shminfo32, shmseg); 1558 CP(u.shminfo, u32.shminfo32, shmall); 1559 error = copyout(&u32.shminfo32, uap->buf, 1560 sizeof(u32.shminfo32)); 1561 break; 1562 case SHM_INFO: 1563 CP(u.shm_info, u32.shm_info32, used_ids); 1564 CP(u.shm_info, u32.shm_info32, shm_rss); 1565 CP(u.shm_info, u32.shm_info32, shm_tot); 1566 CP(u.shm_info, u32.shm_info32, shm_swp); 1567 CP(u.shm_info, u32.shm_info32, swap_attempts); 1568 CP(u.shm_info, u32.shm_info32, swap_successes); 1569 error = copyout(&u32.shm_info32, uap->buf, 1570 sizeof(u32.shm_info32)); 1571 break; 1572 case SHM_STAT: 1573 case IPC_STAT: 1574 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm, 1575 &u32.shmid_ds32.shm_perm); 1576 if (u.shmid_ds.shm_segsz > INT32_MAX) 1577 u32.shmid_ds32.shm_segsz = INT32_MAX; 1578 else 1579 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1580 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1581 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1582 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1583 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1584 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1585 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1586 error = copyout(&u32.shmid_ds32, uap->buf, 1587 sizeof(u32.shmid_ds32)); 1588 break; 1589 } 1590 1591 done: 1592 if (error) { 1593 /* Invalidate the return value */ 1594 td->td_retval[0] = -1; 1595 } 1596 return (error); 1597 } 1598 #endif 1599 1600 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1601 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1602 1603 #ifndef CP 1604 #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0) 1605 #endif 1606 1607 #ifndef _SYS_SYSPROTO_H_ 1608 struct freebsd7_shmctl_args { 1609 int shmid; 1610 int cmd; 1611 struct shmid_ds_old *buf; 1612 }; 1613 #endif 1614 int 1615 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap) 1616 { 1617 int error; 1618 struct shmid_ds_old old; 1619 struct shmid_ds buf; 1620 size_t bufsz; 1621 1622 /* 1623 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 1624 * Linux binaries. If we see the call come through the FreeBSD ABI, 1625 * return an error back to the user since we do not to support this. 1626 */ 1627 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 1628 uap->cmd == SHM_STAT) 1629 return (EINVAL); 1630 1631 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 1632 if (uap->cmd == IPC_SET) { 1633 if ((error = copyin(uap->buf, &old, sizeof(old)))) 1634 goto done; 1635 ipcperm_old2new(&old.shm_perm, &buf.shm_perm); 1636 CP(old, buf, shm_segsz); 1637 CP(old, buf, shm_lpid); 1638 CP(old, buf, shm_cpid); 1639 CP(old, buf, shm_nattch); 1640 CP(old, buf, shm_atime); 1641 CP(old, buf, shm_dtime); 1642 CP(old, buf, shm_ctime); 1643 } 1644 1645 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 1646 if (error) 1647 goto done; 1648 1649 /* Cases in which we need to copyout */ 1650 switch (uap->cmd) { 1651 case IPC_STAT: 1652 memset(&old, 0, sizeof(old)); 1653 ipcperm_new2old(&buf.shm_perm, &old.shm_perm); 1654 if (buf.shm_segsz > INT_MAX) 1655 old.shm_segsz = INT_MAX; 1656 else 1657 CP(buf, old, shm_segsz); 1658 CP(buf, old, shm_lpid); 1659 CP(buf, old, shm_cpid); 1660 if (buf.shm_nattch > SHRT_MAX) 1661 old.shm_nattch = SHRT_MAX; 1662 else 1663 CP(buf, old, shm_nattch); 1664 CP(buf, old, shm_atime); 1665 CP(buf, old, shm_dtime); 1666 CP(buf, old, shm_ctime); 1667 old.shm_internal = NULL; 1668 error = copyout(&old, uap->buf, sizeof(old)); 1669 break; 1670 } 1671 1672 done: 1673 if (error) { 1674 /* Invalidate the return value */ 1675 td->td_retval[0] = -1; 1676 } 1677 return (error); 1678 } 1679 1680 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || 1681 COMPAT_FREEBSD7 */ 1682 1683 static int 1684 sysvshm_modload(struct module *module, int cmd, void *arg) 1685 { 1686 int error = 0; 1687 1688 switch (cmd) { 1689 case MOD_LOAD: 1690 error = shminit(); 1691 if (error != 0) 1692 shmunload(); 1693 break; 1694 case MOD_UNLOAD: 1695 error = shmunload(); 1696 break; 1697 case MOD_SHUTDOWN: 1698 break; 1699 default: 1700 error = EINVAL; 1701 break; 1702 } 1703 return (error); 1704 } 1705 1706 static moduledata_t sysvshm_mod = { 1707 "sysvshm", 1708 &sysvshm_modload, 1709 NULL 1710 }; 1711 1712 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST); 1713 MODULE_VERSION(sysvshm, 1); 1714