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 static void shmexit_myhook(struct vmspace *vm); 141 static void shmfork_myhook(struct proc *p1, struct proc *p2); 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 131072 /* 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 } 609 610 611 #ifndef _SYS_SYSPROTO_H_ 612 struct shmctl_args { 613 int shmid; 614 int cmd; 615 struct shmid_ds *buf; 616 }; 617 #endif 618 int 619 sys_shmctl(struct thread *td, struct shmctl_args *uap) 620 { 621 int error; 622 struct shmid_ds buf; 623 size_t bufsz; 624 625 /* 626 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 627 * Linux binaries. If we see the call come through the FreeBSD ABI, 628 * return an error back to the user since we do not to support this. 629 */ 630 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 631 uap->cmd == SHM_STAT) 632 return (EINVAL); 633 634 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 635 if (uap->cmd == IPC_SET) { 636 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds)))) 637 goto done; 638 } 639 640 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 641 if (error) 642 goto done; 643 644 /* Cases in which we need to copyout */ 645 switch (uap->cmd) { 646 case IPC_STAT: 647 error = copyout(&buf, uap->buf, bufsz); 648 break; 649 } 650 651 done: 652 if (error) { 653 /* Invalidate the return value */ 654 td->td_retval[0] = -1; 655 } 656 return (error); 657 } 658 659 660 static int 661 shmget_existing(struct thread *td, struct shmget_args *uap, int mode, 662 int segnum) 663 { 664 struct shmid_kernel *shmseg; 665 #ifdef MAC 666 int error; 667 #endif 668 669 SYSVSHM_ASSERT_LOCKED(); 670 KASSERT(segnum >= 0 && segnum < shmalloced, 671 ("segnum %d shmalloced %d", segnum, shmalloced)); 672 shmseg = &shmsegs[segnum]; 673 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) 674 return (EEXIST); 675 #ifdef MAC 676 error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg); 677 if (error != 0) 678 return (error); 679 #endif 680 if (uap->size != 0 && uap->size > shmseg->u.shm_segsz) 681 return (EINVAL); 682 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 683 return (0); 684 } 685 686 static int 687 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode) 688 { 689 struct ucred *cred = td->td_ucred; 690 struct shmid_kernel *shmseg; 691 vm_object_t shm_object; 692 int i, segnum; 693 size_t size; 694 695 SYSVSHM_ASSERT_LOCKED(); 696 697 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) 698 return (EINVAL); 699 if (shm_nused >= shminfo.shmmni) /* Any shmids left? */ 700 return (ENOSPC); 701 size = round_page(uap->size); 702 if (shm_committed + btoc(size) > shminfo.shmall) 703 return (ENOMEM); 704 if (shm_last_free < 0) { 705 shmrealloc(); /* Maybe expand the shmsegs[] array. */ 706 for (i = 0; i < shmalloced; i++) 707 if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE) 708 break; 709 if (i == shmalloced) 710 return (ENOSPC); 711 segnum = i; 712 } else { 713 segnum = shm_last_free; 714 shm_last_free = -1; 715 } 716 KASSERT(segnum >= 0 && segnum < shmalloced, 717 ("segnum %d shmalloced %d", segnum, shmalloced)); 718 shmseg = &shmsegs[segnum]; 719 #ifdef RACCT 720 if (racct_enable) { 721 PROC_LOCK(td->td_proc); 722 if (racct_add(td->td_proc, RACCT_NSHM, 1)) { 723 PROC_UNLOCK(td->td_proc); 724 return (ENOSPC); 725 } 726 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) { 727 racct_sub(td->td_proc, RACCT_NSHM, 1); 728 PROC_UNLOCK(td->td_proc); 729 return (ENOMEM); 730 } 731 PROC_UNLOCK(td->td_proc); 732 } 733 #endif 734 735 /* 736 * We make sure that we have allocated a pager before we need 737 * to. 738 */ 739 shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP, 740 0, size, VM_PROT_DEFAULT, 0, cred); 741 if (shm_object == NULL) { 742 #ifdef RACCT 743 if (racct_enable) { 744 PROC_LOCK(td->td_proc); 745 racct_sub(td->td_proc, RACCT_NSHM, 1); 746 racct_sub(td->td_proc, RACCT_SHMSIZE, size); 747 PROC_UNLOCK(td->td_proc); 748 } 749 #endif 750 return (ENOMEM); 751 } 752 shm_object->pg_color = 0; 753 VM_OBJECT_WLOCK(shm_object); 754 vm_object_clear_flag(shm_object, OBJ_ONEMAPPING); 755 vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT); 756 VM_OBJECT_WUNLOCK(shm_object); 757 758 shmseg->object = shm_object; 759 shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid; 760 shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid; 761 shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; 762 shmseg->u.shm_perm.key = uap->key; 763 shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff; 764 shmseg->cred = crhold(cred); 765 shmseg->u.shm_segsz = uap->size; 766 shmseg->u.shm_cpid = td->td_proc->p_pid; 767 shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0; 768 shmseg->u.shm_atime = shmseg->u.shm_dtime = 0; 769 #ifdef MAC 770 mac_sysvshm_create(cred, shmseg); 771 #endif 772 shmseg->u.shm_ctime = time_second; 773 shm_committed += btoc(size); 774 shm_nused++; 775 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 776 777 return (0); 778 } 779 780 #ifndef _SYS_SYSPROTO_H_ 781 struct shmget_args { 782 key_t key; 783 size_t size; 784 int shmflg; 785 }; 786 #endif 787 int 788 sys_shmget(struct thread *td, struct shmget_args *uap) 789 { 790 int segnum, mode; 791 int error; 792 793 if (shm_find_prison(td->td_ucred) == NULL) 794 return (ENOSYS); 795 mode = uap->shmflg & ACCESSPERMS; 796 SYSVSHM_LOCK(); 797 if (uap->key == IPC_PRIVATE) { 798 error = shmget_allocate_segment(td, uap, mode); 799 } else { 800 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison, 801 uap->key); 802 if (segnum >= 0) 803 error = shmget_existing(td, uap, mode, segnum); 804 else if ((uap->shmflg & IPC_CREAT) == 0) 805 error = ENOENT; 806 else 807 error = shmget_allocate_segment(td, uap, mode); 808 } 809 SYSVSHM_UNLOCK(); 810 return (error); 811 } 812 813 static void 814 shmfork_myhook(struct proc *p1, struct proc *p2) 815 { 816 struct shmmap_state *shmmap_s; 817 size_t size; 818 int i; 819 820 SYSVSHM_LOCK(); 821 size = shminfo.shmseg * sizeof(struct shmmap_state); 822 shmmap_s = malloc(size, M_SHM, M_WAITOK); 823 bcopy(p1->p_vmspace->vm_shm, shmmap_s, size); 824 p2->p_vmspace->vm_shm = shmmap_s; 825 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 826 if (shmmap_s->shmid != -1) { 827 KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 && 828 IPCID_TO_IX(shmmap_s->shmid) < shmalloced, 829 ("segnum %d shmalloced %d", 830 IPCID_TO_IX(shmmap_s->shmid), shmalloced)); 831 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++; 832 } 833 } 834 SYSVSHM_UNLOCK(); 835 } 836 837 static void 838 shmexit_myhook(struct vmspace *vm) 839 { 840 struct shmmap_state *base, *shm; 841 int i; 842 843 base = vm->vm_shm; 844 if (base != NULL) { 845 vm->vm_shm = NULL; 846 SYSVSHM_LOCK(); 847 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) { 848 if (shm->shmid != -1) 849 shm_delete_mapping(vm, shm); 850 } 851 SYSVSHM_UNLOCK(); 852 free(base, M_SHM); 853 } 854 } 855 856 static void 857 shmrealloc(void) 858 { 859 struct shmid_kernel *newsegs; 860 int i; 861 862 SYSVSHM_ASSERT_LOCKED(); 863 864 if (shmalloced >= shminfo.shmmni) 865 return; 866 867 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, 868 M_WAITOK | M_ZERO); 869 for (i = 0; i < shmalloced; i++) 870 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 871 for (; i < shminfo.shmmni; i++) { 872 newsegs[i].u.shm_perm.mode = SHMSEG_FREE; 873 newsegs[i].u.shm_perm.seq = 0; 874 #ifdef MAC 875 mac_sysvshm_init(&newsegs[i]); 876 #endif 877 } 878 free(shmsegs, M_SHM); 879 shmsegs = newsegs; 880 shmalloced = shminfo.shmmni; 881 } 882 883 static struct syscall_helper_data shm_syscalls[] = { 884 SYSCALL_INIT_HELPER(shmat), 885 SYSCALL_INIT_HELPER(shmctl), 886 SYSCALL_INIT_HELPER(shmdt), 887 SYSCALL_INIT_HELPER(shmget), 888 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 889 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 890 SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl), 891 #endif 892 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 893 SYSCALL_INIT_HELPER(shmsys), 894 #endif 895 SYSCALL_INIT_LAST 896 }; 897 898 #ifdef COMPAT_FREEBSD32 899 #include <compat/freebsd32/freebsd32.h> 900 #include <compat/freebsd32/freebsd32_ipc.h> 901 #include <compat/freebsd32/freebsd32_proto.h> 902 #include <compat/freebsd32/freebsd32_signal.h> 903 #include <compat/freebsd32/freebsd32_syscall.h> 904 #include <compat/freebsd32/freebsd32_util.h> 905 906 static struct syscall_helper_data shm32_syscalls[] = { 907 SYSCALL32_INIT_HELPER_COMPAT(shmat), 908 SYSCALL32_INIT_HELPER_COMPAT(shmdt), 909 SYSCALL32_INIT_HELPER_COMPAT(shmget), 910 SYSCALL32_INIT_HELPER(freebsd32_shmsys), 911 SYSCALL32_INIT_HELPER(freebsd32_shmctl), 912 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 913 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 914 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl), 915 #endif 916 SYSCALL_INIT_LAST 917 }; 918 #endif 919 920 static int 921 shminit(void) 922 { 923 struct prison *pr; 924 void **rsv; 925 int i, error; 926 osd_method_t methods[PR_MAXMETHOD] = { 927 [PR_METHOD_CHECK] = shm_prison_check, 928 [PR_METHOD_SET] = shm_prison_set, 929 [PR_METHOD_GET] = shm_prison_get, 930 [PR_METHOD_REMOVE] = shm_prison_remove, 931 }; 932 933 #ifndef BURN_BRIDGES 934 if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0) 935 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n"); 936 #endif 937 if (shminfo.shmmax == SHMMAX) { 938 /* Initialize shmmax dealing with possible overflow. */ 939 for (i = PAGE_SIZE; i != 0; i--) { 940 shminfo.shmmax = shminfo.shmall * i; 941 if ((shminfo.shmmax / shminfo.shmall) == (u_long)i) 942 break; 943 } 944 } 945 shmalloced = shminfo.shmmni; 946 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, 947 M_WAITOK|M_ZERO); 948 for (i = 0; i < shmalloced; i++) { 949 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; 950 shmsegs[i].u.shm_perm.seq = 0; 951 #ifdef MAC 952 mac_sysvshm_init(&shmsegs[i]); 953 #endif 954 } 955 shm_last_free = 0; 956 shm_nused = 0; 957 shm_committed = 0; 958 sx_init(&sysvshmsx, "sysvshmsx"); 959 shmexit_hook = &shmexit_myhook; 960 shmfork_hook = &shmfork_myhook; 961 962 /* Set current prisons according to their allow.sysvipc. */ 963 shm_prison_slot = osd_jail_register(NULL, methods); 964 rsv = osd_reserve(shm_prison_slot); 965 prison_lock(&prison0); 966 (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0); 967 prison_unlock(&prison0); 968 rsv = NULL; 969 sx_slock(&allprison_lock); 970 TAILQ_FOREACH(pr, &allprison, pr_list) { 971 if (rsv == NULL) 972 rsv = osd_reserve(shm_prison_slot); 973 prison_lock(pr); 974 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) { 975 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 976 &prison0); 977 rsv = NULL; 978 } 979 prison_unlock(pr); 980 } 981 if (rsv != NULL) 982 osd_free_reserved(rsv); 983 sx_sunlock(&allprison_lock); 984 985 error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD); 986 if (error != 0) 987 return (error); 988 #ifdef COMPAT_FREEBSD32 989 error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD); 990 if (error != 0) 991 return (error); 992 #endif 993 return (0); 994 } 995 996 static int 997 shmunload(void) 998 { 999 int i; 1000 1001 if (shm_nused > 0) 1002 return (EBUSY); 1003 1004 #ifdef COMPAT_FREEBSD32 1005 syscall32_helper_unregister(shm32_syscalls); 1006 #endif 1007 syscall_helper_unregister(shm_syscalls); 1008 if (shm_prison_slot != 0) 1009 osd_jail_deregister(shm_prison_slot); 1010 1011 for (i = 0; i < shmalloced; i++) { 1012 #ifdef MAC 1013 mac_sysvshm_destroy(&shmsegs[i]); 1014 #endif 1015 /* 1016 * Objects might be still mapped into the processes 1017 * address spaces. Actual free would happen on the 1018 * last mapping destruction. 1019 */ 1020 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE) 1021 vm_object_deallocate(shmsegs[i].object); 1022 } 1023 free(shmsegs, M_SHM); 1024 shmexit_hook = NULL; 1025 shmfork_hook = NULL; 1026 sx_destroy(&sysvshmsx); 1027 return (0); 1028 } 1029 1030 static int 1031 sysctl_shmsegs(SYSCTL_HANDLER_ARGS) 1032 { 1033 struct shmid_kernel tshmseg; 1034 #ifdef COMPAT_FREEBSD32 1035 struct shmid_kernel32 tshmseg32; 1036 #endif 1037 struct prison *pr, *rpr; 1038 void *outaddr; 1039 size_t outsize; 1040 int error, i; 1041 1042 SYSVSHM_LOCK(); 1043 pr = req->td->td_ucred->cr_prison; 1044 rpr = shm_find_prison(req->td->td_ucred); 1045 error = 0; 1046 for (i = 0; i < shmalloced; i++) { 1047 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 1048 rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) { 1049 bzero(&tshmseg, sizeof(tshmseg)); 1050 tshmseg.u.shm_perm.mode = SHMSEG_FREE; 1051 } else { 1052 tshmseg = shmsegs[i]; 1053 if (tshmseg.cred->cr_prison != pr) 1054 tshmseg.u.shm_perm.key = IPC_PRIVATE; 1055 } 1056 #ifdef COMPAT_FREEBSD32 1057 if (SV_CURPROC_FLAG(SV_ILP32)) { 1058 bzero(&tshmseg32, sizeof(tshmseg32)); 1059 freebsd32_ipcperm_out(&tshmseg.u.shm_perm, 1060 &tshmseg32.u.shm_perm); 1061 CP(tshmseg, tshmseg32, u.shm_segsz); 1062 CP(tshmseg, tshmseg32, u.shm_lpid); 1063 CP(tshmseg, tshmseg32, u.shm_cpid); 1064 CP(tshmseg, tshmseg32, u.shm_nattch); 1065 CP(tshmseg, tshmseg32, u.shm_atime); 1066 CP(tshmseg, tshmseg32, u.shm_dtime); 1067 CP(tshmseg, tshmseg32, u.shm_ctime); 1068 /* Don't copy object, label, or cred */ 1069 outaddr = &tshmseg32; 1070 outsize = sizeof(tshmseg32); 1071 } else 1072 #endif 1073 { 1074 tshmseg.object = NULL; 1075 tshmseg.label = NULL; 1076 tshmseg.cred = NULL; 1077 outaddr = &tshmseg; 1078 outsize = sizeof(tshmseg); 1079 } 1080 error = SYSCTL_OUT(req, outaddr, outsize); 1081 if (error != 0) 1082 break; 1083 } 1084 SYSVSHM_UNLOCK(); 1085 return (error); 1086 } 1087 1088 static int 1089 shm_prison_check(void *obj, void *data) 1090 { 1091 struct prison *pr = obj; 1092 struct prison *prpr; 1093 struct vfsoptlist *opts = data; 1094 int error, jsys; 1095 1096 /* 1097 * sysvshm is a jailsys integer. 1098 * It must be "disable" if the parent jail is disabled. 1099 */ 1100 error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1101 if (error != ENOENT) { 1102 if (error != 0) 1103 return (error); 1104 switch (jsys) { 1105 case JAIL_SYS_DISABLE: 1106 break; 1107 case JAIL_SYS_NEW: 1108 case JAIL_SYS_INHERIT: 1109 prison_lock(pr->pr_parent); 1110 prpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1111 prison_unlock(pr->pr_parent); 1112 if (prpr == NULL) 1113 return (EPERM); 1114 break; 1115 default: 1116 return (EINVAL); 1117 } 1118 } 1119 1120 return (0); 1121 } 1122 1123 static int 1124 shm_prison_set(void *obj, void *data) 1125 { 1126 struct prison *pr = obj; 1127 struct prison *tpr, *orpr, *nrpr, *trpr; 1128 struct vfsoptlist *opts = data; 1129 void *rsv; 1130 int jsys, descend; 1131 1132 /* 1133 * sysvshm controls which jail is the root of the associated segments 1134 * (this jail or same as the parent), or if the feature is available 1135 * at all. 1136 */ 1137 if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT) 1138 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0) 1139 ? JAIL_SYS_INHERIT 1140 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0) 1141 ? JAIL_SYS_DISABLE 1142 : -1; 1143 if (jsys == JAIL_SYS_DISABLE) { 1144 prison_lock(pr); 1145 orpr = osd_jail_get(pr, shm_prison_slot); 1146 if (orpr != NULL) 1147 osd_jail_del(pr, shm_prison_slot); 1148 prison_unlock(pr); 1149 if (orpr != NULL) { 1150 if (orpr == pr) 1151 shm_prison_cleanup(pr); 1152 /* Disable all child jails as well. */ 1153 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1154 prison_lock(tpr); 1155 trpr = osd_jail_get(tpr, shm_prison_slot); 1156 if (trpr != NULL) { 1157 osd_jail_del(tpr, shm_prison_slot); 1158 prison_unlock(tpr); 1159 if (trpr == tpr) 1160 shm_prison_cleanup(tpr); 1161 } else { 1162 prison_unlock(tpr); 1163 descend = 0; 1164 } 1165 } 1166 } 1167 } else if (jsys != -1) { 1168 if (jsys == JAIL_SYS_NEW) 1169 nrpr = pr; 1170 else { 1171 prison_lock(pr->pr_parent); 1172 nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1173 prison_unlock(pr->pr_parent); 1174 } 1175 rsv = osd_reserve(shm_prison_slot); 1176 prison_lock(pr); 1177 orpr = osd_jail_get(pr, shm_prison_slot); 1178 if (orpr != nrpr) 1179 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 1180 nrpr); 1181 else 1182 osd_free_reserved(rsv); 1183 prison_unlock(pr); 1184 if (orpr != nrpr) { 1185 if (orpr == pr) 1186 shm_prison_cleanup(pr); 1187 if (orpr != NULL) { 1188 /* Change child jails matching the old root, */ 1189 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1190 prison_lock(tpr); 1191 trpr = osd_jail_get(tpr, 1192 shm_prison_slot); 1193 if (trpr == orpr) { 1194 (void)osd_jail_set(tpr, 1195 shm_prison_slot, nrpr); 1196 prison_unlock(tpr); 1197 if (trpr == tpr) 1198 shm_prison_cleanup(tpr); 1199 } else { 1200 prison_unlock(tpr); 1201 descend = 0; 1202 } 1203 } 1204 } 1205 } 1206 } 1207 1208 return (0); 1209 } 1210 1211 static int 1212 shm_prison_get(void *obj, void *data) 1213 { 1214 struct prison *pr = obj; 1215 struct prison *rpr; 1216 struct vfsoptlist *opts = data; 1217 int error, jsys; 1218 1219 /* Set sysvshm based on the jail's root prison. */ 1220 prison_lock(pr); 1221 rpr = osd_jail_get(pr, shm_prison_slot); 1222 prison_unlock(pr); 1223 jsys = rpr == NULL ? JAIL_SYS_DISABLE 1224 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT; 1225 error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1226 if (error == ENOENT) 1227 error = 0; 1228 return (error); 1229 } 1230 1231 static int 1232 shm_prison_remove(void *obj, void *data __unused) 1233 { 1234 struct prison *pr = obj; 1235 struct prison *rpr; 1236 1237 SYSVSHM_LOCK(); 1238 prison_lock(pr); 1239 rpr = osd_jail_get(pr, shm_prison_slot); 1240 prison_unlock(pr); 1241 if (rpr == pr) 1242 shm_prison_cleanup(pr); 1243 SYSVSHM_UNLOCK(); 1244 return (0); 1245 } 1246 1247 static void 1248 shm_prison_cleanup(struct prison *pr) 1249 { 1250 struct shmid_kernel *shmseg; 1251 int i; 1252 1253 /* Remove any segments that belong to this jail. */ 1254 for (i = 0; i < shmalloced; i++) { 1255 shmseg = &shmsegs[i]; 1256 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) && 1257 shmseg->cred != NULL && shmseg->cred->cr_prison == pr) { 1258 shm_remove(shmseg, i); 1259 } 1260 } 1261 } 1262 1263 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory"); 1264 1265 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 1266 struct oshmid_ds { 1267 struct ipc_perm_old shm_perm; /* operation perms */ 1268 int shm_segsz; /* size of segment (bytes) */ 1269 u_short shm_cpid; /* pid, creator */ 1270 u_short shm_lpid; /* pid, last operation */ 1271 short shm_nattch; /* no. of current attaches */ 1272 time_t shm_atime; /* last attach time */ 1273 time_t shm_dtime; /* last detach time */ 1274 time_t shm_ctime; /* last change time */ 1275 void *shm_handle; /* internal handle for shm segment */ 1276 }; 1277 1278 struct oshmctl_args { 1279 int shmid; 1280 int cmd; 1281 struct oshmid_ds *ubuf; 1282 }; 1283 1284 static int 1285 oshmctl(struct thread *td, struct oshmctl_args *uap) 1286 { 1287 #ifdef COMPAT_43 1288 int error = 0; 1289 struct prison *rpr; 1290 struct shmid_kernel *shmseg; 1291 struct oshmid_ds outbuf; 1292 1293 rpr = shm_find_prison(td->td_ucred); 1294 if (rpr == NULL) 1295 return (ENOSYS); 1296 if (uap->cmd != IPC_STAT) { 1297 return (freebsd7_shmctl(td, 1298 (struct freebsd7_shmctl_args *)uap)); 1299 } 1300 SYSVSHM_LOCK(); 1301 shmseg = shm_find_segment(rpr, uap->shmid, true); 1302 if (shmseg == NULL) { 1303 SYSVSHM_UNLOCK(); 1304 return (EINVAL); 1305 } 1306 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 1307 if (error != 0) { 1308 SYSVSHM_UNLOCK(); 1309 return (error); 1310 } 1311 #ifdef MAC 1312 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd); 1313 if (error != 0) { 1314 SYSVSHM_UNLOCK(); 1315 return (error); 1316 } 1317 #endif 1318 ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm); 1319 outbuf.shm_segsz = shmseg->u.shm_segsz; 1320 outbuf.shm_cpid = shmseg->u.shm_cpid; 1321 outbuf.shm_lpid = shmseg->u.shm_lpid; 1322 outbuf.shm_nattch = shmseg->u.shm_nattch; 1323 outbuf.shm_atime = shmseg->u.shm_atime; 1324 outbuf.shm_dtime = shmseg->u.shm_dtime; 1325 outbuf.shm_ctime = shmseg->u.shm_ctime; 1326 outbuf.shm_handle = shmseg->object; 1327 SYSVSHM_UNLOCK(); 1328 return (copyout(&outbuf, uap->ubuf, sizeof(outbuf))); 1329 #else 1330 return (EINVAL); 1331 #endif 1332 } 1333 1334 /* XXX casting to (sy_call_t *) is bogus, as usual. */ 1335 static sy_call_t *shmcalls[] = { 1336 (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl, 1337 (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget, 1338 (sy_call_t *)freebsd7_shmctl 1339 }; 1340 1341 #ifndef _SYS_SYSPROTO_H_ 1342 /* XXX actually varargs. */ 1343 struct shmsys_args { 1344 int which; 1345 int a2; 1346 int a3; 1347 int a4; 1348 }; 1349 #endif 1350 int 1351 sys_shmsys(struct thread *td, struct shmsys_args *uap) 1352 { 1353 1354 AUDIT_ARG_SVIPC_WHICH(uap->which); 1355 if (uap->which < 0 || uap->which >= nitems(shmcalls)) 1356 return (EINVAL); 1357 return ((*shmcalls[uap->which])(td, &uap->a2)); 1358 } 1359 1360 #endif /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */ 1361 1362 #ifdef COMPAT_FREEBSD32 1363 1364 int 1365 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap) 1366 { 1367 1368 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1369 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1370 AUDIT_ARG_SVIPC_WHICH(uap->which); 1371 switch (uap->which) { 1372 case 0: { /* shmat */ 1373 struct shmat_args ap; 1374 1375 ap.shmid = uap->a2; 1376 ap.shmaddr = PTRIN(uap->a3); 1377 ap.shmflg = uap->a4; 1378 return (sysent[SYS_shmat].sy_call(td, &ap)); 1379 } 1380 case 2: { /* shmdt */ 1381 struct shmdt_args ap; 1382 1383 ap.shmaddr = PTRIN(uap->a2); 1384 return (sysent[SYS_shmdt].sy_call(td, &ap)); 1385 } 1386 case 3: { /* shmget */ 1387 struct shmget_args ap; 1388 1389 ap.key = uap->a2; 1390 ap.size = uap->a3; 1391 ap.shmflg = uap->a4; 1392 return (sysent[SYS_shmget].sy_call(td, &ap)); 1393 } 1394 case 4: { /* shmctl */ 1395 struct freebsd7_freebsd32_shmctl_args ap; 1396 1397 ap.shmid = uap->a2; 1398 ap.cmd = uap->a3; 1399 ap.buf = PTRIN(uap->a4); 1400 return (freebsd7_freebsd32_shmctl(td, &ap)); 1401 } 1402 case 1: /* oshmctl */ 1403 default: 1404 return (EINVAL); 1405 } 1406 #else 1407 return (nosys(td, NULL)); 1408 #endif 1409 } 1410 1411 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1412 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1413 int 1414 freebsd7_freebsd32_shmctl(struct thread *td, 1415 struct freebsd7_freebsd32_shmctl_args *uap) 1416 { 1417 int error; 1418 union { 1419 struct shmid_ds shmid_ds; 1420 struct shm_info shm_info; 1421 struct shminfo shminfo; 1422 } u; 1423 union { 1424 struct shmid_ds32_old shmid_ds32; 1425 struct shm_info32 shm_info32; 1426 struct shminfo32 shminfo32; 1427 } u32; 1428 size_t sz; 1429 1430 if (uap->cmd == IPC_SET) { 1431 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1432 sizeof(u32.shmid_ds32)))) 1433 goto done; 1434 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm, 1435 &u.shmid_ds.shm_perm); 1436 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1437 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1438 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1439 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1440 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1441 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1442 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1443 } 1444 1445 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1446 if (error) 1447 goto done; 1448 1449 /* Cases in which we need to copyout */ 1450 switch (uap->cmd) { 1451 case IPC_INFO: 1452 CP(u.shminfo, u32.shminfo32, shmmax); 1453 CP(u.shminfo, u32.shminfo32, shmmin); 1454 CP(u.shminfo, u32.shminfo32, shmmni); 1455 CP(u.shminfo, u32.shminfo32, shmseg); 1456 CP(u.shminfo, u32.shminfo32, shmall); 1457 error = copyout(&u32.shminfo32, uap->buf, 1458 sizeof(u32.shminfo32)); 1459 break; 1460 case SHM_INFO: 1461 CP(u.shm_info, u32.shm_info32, used_ids); 1462 CP(u.shm_info, u32.shm_info32, shm_rss); 1463 CP(u.shm_info, u32.shm_info32, shm_tot); 1464 CP(u.shm_info, u32.shm_info32, shm_swp); 1465 CP(u.shm_info, u32.shm_info32, swap_attempts); 1466 CP(u.shm_info, u32.shm_info32, swap_successes); 1467 error = copyout(&u32.shm_info32, uap->buf, 1468 sizeof(u32.shm_info32)); 1469 break; 1470 case SHM_STAT: 1471 case IPC_STAT: 1472 memset(&u32.shmid_ds32, 0, sizeof(u32.shmid_ds32)); 1473 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm, 1474 &u32.shmid_ds32.shm_perm); 1475 if (u.shmid_ds.shm_segsz > INT32_MAX) 1476 u32.shmid_ds32.shm_segsz = INT32_MAX; 1477 else 1478 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1479 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1480 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1481 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1482 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1483 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1484 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1485 u32.shmid_ds32.shm_internal = 0; 1486 error = copyout(&u32.shmid_ds32, uap->buf, 1487 sizeof(u32.shmid_ds32)); 1488 break; 1489 } 1490 1491 done: 1492 if (error) { 1493 /* Invalidate the return value */ 1494 td->td_retval[0] = -1; 1495 } 1496 return (error); 1497 } 1498 #endif 1499 1500 int 1501 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap) 1502 { 1503 int error; 1504 union { 1505 struct shmid_ds shmid_ds; 1506 struct shm_info shm_info; 1507 struct shminfo shminfo; 1508 } u; 1509 union { 1510 struct shmid_ds32 shmid_ds32; 1511 struct shm_info32 shm_info32; 1512 struct shminfo32 shminfo32; 1513 } u32; 1514 size_t sz; 1515 1516 if (uap->cmd == IPC_SET) { 1517 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1518 sizeof(u32.shmid_ds32)))) 1519 goto done; 1520 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm, 1521 &u.shmid_ds.shm_perm); 1522 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1523 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1524 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1525 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1526 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1527 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1528 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1529 } 1530 1531 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1532 if (error) 1533 goto done; 1534 1535 /* Cases in which we need to copyout */ 1536 switch (uap->cmd) { 1537 case IPC_INFO: 1538 CP(u.shminfo, u32.shminfo32, shmmax); 1539 CP(u.shminfo, u32.shminfo32, shmmin); 1540 CP(u.shminfo, u32.shminfo32, shmmni); 1541 CP(u.shminfo, u32.shminfo32, shmseg); 1542 CP(u.shminfo, u32.shminfo32, shmall); 1543 error = copyout(&u32.shminfo32, uap->buf, 1544 sizeof(u32.shminfo32)); 1545 break; 1546 case SHM_INFO: 1547 CP(u.shm_info, u32.shm_info32, used_ids); 1548 CP(u.shm_info, u32.shm_info32, shm_rss); 1549 CP(u.shm_info, u32.shm_info32, shm_tot); 1550 CP(u.shm_info, u32.shm_info32, shm_swp); 1551 CP(u.shm_info, u32.shm_info32, swap_attempts); 1552 CP(u.shm_info, u32.shm_info32, swap_successes); 1553 error = copyout(&u32.shm_info32, uap->buf, 1554 sizeof(u32.shm_info32)); 1555 break; 1556 case SHM_STAT: 1557 case IPC_STAT: 1558 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm, 1559 &u32.shmid_ds32.shm_perm); 1560 if (u.shmid_ds.shm_segsz > INT32_MAX) 1561 u32.shmid_ds32.shm_segsz = INT32_MAX; 1562 else 1563 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1564 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1565 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1566 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1567 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1568 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1569 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1570 error = copyout(&u32.shmid_ds32, uap->buf, 1571 sizeof(u32.shmid_ds32)); 1572 break; 1573 } 1574 1575 done: 1576 if (error) { 1577 /* Invalidate the return value */ 1578 td->td_retval[0] = -1; 1579 } 1580 return (error); 1581 } 1582 #endif 1583 1584 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1585 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1586 1587 #ifndef CP 1588 #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0) 1589 #endif 1590 1591 #ifndef _SYS_SYSPROTO_H_ 1592 struct freebsd7_shmctl_args { 1593 int shmid; 1594 int cmd; 1595 struct shmid_ds_old *buf; 1596 }; 1597 #endif 1598 int 1599 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap) 1600 { 1601 int error; 1602 struct shmid_ds_old old; 1603 struct shmid_ds buf; 1604 size_t bufsz; 1605 1606 /* 1607 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 1608 * Linux binaries. If we see the call come through the FreeBSD ABI, 1609 * return an error back to the user since we do not to support this. 1610 */ 1611 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 1612 uap->cmd == SHM_STAT) 1613 return (EINVAL); 1614 1615 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 1616 if (uap->cmd == IPC_SET) { 1617 if ((error = copyin(uap->buf, &old, sizeof(old)))) 1618 goto done; 1619 ipcperm_old2new(&old.shm_perm, &buf.shm_perm); 1620 CP(old, buf, shm_segsz); 1621 CP(old, buf, shm_lpid); 1622 CP(old, buf, shm_cpid); 1623 CP(old, buf, shm_nattch); 1624 CP(old, buf, shm_atime); 1625 CP(old, buf, shm_dtime); 1626 CP(old, buf, shm_ctime); 1627 } 1628 1629 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 1630 if (error) 1631 goto done; 1632 1633 /* Cases in which we need to copyout */ 1634 switch (uap->cmd) { 1635 case IPC_STAT: 1636 memset(&old, 0, sizeof(old)); 1637 ipcperm_new2old(&buf.shm_perm, &old.shm_perm); 1638 if (buf.shm_segsz > INT_MAX) 1639 old.shm_segsz = INT_MAX; 1640 else 1641 CP(buf, old, shm_segsz); 1642 CP(buf, old, shm_lpid); 1643 CP(buf, old, shm_cpid); 1644 if (buf.shm_nattch > SHRT_MAX) 1645 old.shm_nattch = SHRT_MAX; 1646 else 1647 CP(buf, old, shm_nattch); 1648 CP(buf, old, shm_atime); 1649 CP(buf, old, shm_dtime); 1650 CP(buf, old, shm_ctime); 1651 old.shm_internal = NULL; 1652 error = copyout(&old, uap->buf, sizeof(old)); 1653 break; 1654 } 1655 1656 done: 1657 if (error) { 1658 /* Invalidate the return value */ 1659 td->td_retval[0] = -1; 1660 } 1661 return (error); 1662 } 1663 1664 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || 1665 COMPAT_FREEBSD7 */ 1666 1667 static int 1668 sysvshm_modload(struct module *module, int cmd, void *arg) 1669 { 1670 int error = 0; 1671 1672 switch (cmd) { 1673 case MOD_LOAD: 1674 error = shminit(); 1675 if (error != 0) 1676 shmunload(); 1677 break; 1678 case MOD_UNLOAD: 1679 error = shmunload(); 1680 break; 1681 case MOD_SHUTDOWN: 1682 break; 1683 default: 1684 error = EINVAL; 1685 break; 1686 } 1687 return (error); 1688 } 1689 1690 static moduledata_t sysvshm_mod = { 1691 "sysvshm", 1692 &sysvshm_modload, 1693 NULL 1694 }; 1695 1696 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST); 1697 MODULE_VERSION(sysvshm, 1); 1698