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 #ifndef _SYS_SYSPROTO_H_ 613 struct shmctl_args { 614 int shmid; 615 int cmd; 616 struct shmid_ds *buf; 617 }; 618 #endif 619 int 620 sys_shmctl(struct thread *td, struct shmctl_args *uap) 621 { 622 int error; 623 struct shmid_ds buf; 624 size_t bufsz; 625 626 /* 627 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 628 * Linux binaries. If we see the call come through the FreeBSD ABI, 629 * return an error back to the user since we do not to support this. 630 */ 631 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 632 uap->cmd == SHM_STAT) 633 return (EINVAL); 634 635 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 636 if (uap->cmd == IPC_SET) { 637 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds)))) 638 goto done; 639 } 640 641 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 642 if (error) 643 goto done; 644 645 /* Cases in which we need to copyout */ 646 switch (uap->cmd) { 647 case IPC_STAT: 648 error = copyout(&buf, uap->buf, bufsz); 649 break; 650 } 651 652 done: 653 if (error) { 654 /* Invalidate the return value */ 655 td->td_retval[0] = -1; 656 } 657 return (error); 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 } 752 753 shmseg->object = shm_object; 754 shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid; 755 shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid; 756 shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; 757 shmseg->u.shm_perm.key = uap->key; 758 shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff; 759 shmseg->cred = crhold(cred); 760 shmseg->u.shm_segsz = uap->size; 761 shmseg->u.shm_cpid = td->td_proc->p_pid; 762 shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0; 763 shmseg->u.shm_atime = shmseg->u.shm_dtime = 0; 764 #ifdef MAC 765 mac_sysvshm_create(cred, shmseg); 766 #endif 767 shmseg->u.shm_ctime = time_second; 768 shm_committed += btoc(size); 769 shm_nused++; 770 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 771 772 return (0); 773 } 774 775 #ifndef _SYS_SYSPROTO_H_ 776 struct shmget_args { 777 key_t key; 778 size_t size; 779 int shmflg; 780 }; 781 #endif 782 int 783 sys_shmget(struct thread *td, struct shmget_args *uap) 784 { 785 int segnum, mode; 786 int error; 787 788 if (shm_find_prison(td->td_ucred) == NULL) 789 return (ENOSYS); 790 mode = uap->shmflg & ACCESSPERMS; 791 SYSVSHM_LOCK(); 792 if (uap->key == IPC_PRIVATE) { 793 error = shmget_allocate_segment(td, uap, mode); 794 } else { 795 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison, 796 uap->key); 797 if (segnum >= 0) 798 error = shmget_existing(td, uap, mode, segnum); 799 else if ((uap->shmflg & IPC_CREAT) == 0) 800 error = ENOENT; 801 else 802 error = shmget_allocate_segment(td, uap, mode); 803 } 804 SYSVSHM_UNLOCK(); 805 return (error); 806 } 807 808 #ifdef SYSVSHM 809 void 810 shmfork(struct proc *p1, struct proc *p2) 811 #else 812 static void 813 shmfork_myhook(struct proc *p1, struct proc *p2) 814 #endif 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 #ifdef SYSVSHM 838 void 839 shmexit(struct vmspace *vm) 840 #else 841 static void 842 shmexit_myhook(struct vmspace *vm) 843 #endif 844 { 845 struct shmmap_state *base, *shm; 846 int i; 847 848 base = vm->vm_shm; 849 if (base != NULL) { 850 vm->vm_shm = NULL; 851 SYSVSHM_LOCK(); 852 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) { 853 if (shm->shmid != -1) 854 shm_delete_mapping(vm, shm); 855 } 856 SYSVSHM_UNLOCK(); 857 free(base, M_SHM); 858 } 859 } 860 861 static void 862 shmrealloc(void) 863 { 864 struct shmid_kernel *newsegs; 865 int i; 866 867 SYSVSHM_ASSERT_LOCKED(); 868 869 if (shmalloced >= shminfo.shmmni) 870 return; 871 872 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, 873 M_WAITOK | M_ZERO); 874 for (i = 0; i < shmalloced; i++) 875 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 876 for (; i < shminfo.shmmni; i++) { 877 newsegs[i].u.shm_perm.mode = SHMSEG_FREE; 878 newsegs[i].u.shm_perm.seq = 0; 879 #ifdef MAC 880 mac_sysvshm_init(&newsegs[i]); 881 #endif 882 } 883 free(shmsegs, M_SHM); 884 shmsegs = newsegs; 885 shmalloced = shminfo.shmmni; 886 } 887 888 static struct syscall_helper_data shm_syscalls[] = { 889 SYSCALL_INIT_HELPER(shmat), 890 SYSCALL_INIT_HELPER(shmctl), 891 SYSCALL_INIT_HELPER(shmdt), 892 SYSCALL_INIT_HELPER(shmget), 893 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 894 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 895 SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl), 896 #endif 897 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 898 SYSCALL_INIT_HELPER(shmsys), 899 #endif 900 SYSCALL_INIT_LAST 901 }; 902 903 #ifdef COMPAT_FREEBSD32 904 #include <compat/freebsd32/freebsd32.h> 905 #include <compat/freebsd32/freebsd32_ipc.h> 906 #include <compat/freebsd32/freebsd32_proto.h> 907 #include <compat/freebsd32/freebsd32_signal.h> 908 #include <compat/freebsd32/freebsd32_syscall.h> 909 #include <compat/freebsd32/freebsd32_util.h> 910 911 static struct syscall_helper_data shm32_syscalls[] = { 912 SYSCALL32_INIT_HELPER_COMPAT(shmat), 913 SYSCALL32_INIT_HELPER_COMPAT(shmdt), 914 SYSCALL32_INIT_HELPER_COMPAT(shmget), 915 SYSCALL32_INIT_HELPER(freebsd32_shmsys), 916 SYSCALL32_INIT_HELPER(freebsd32_shmctl), 917 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 918 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 919 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl), 920 #endif 921 SYSCALL_INIT_LAST 922 }; 923 #endif 924 925 static int 926 shminit(void) 927 { 928 struct prison *pr; 929 void **rsv; 930 int i, error; 931 osd_method_t methods[PR_MAXMETHOD] = { 932 [PR_METHOD_CHECK] = shm_prison_check, 933 [PR_METHOD_SET] = shm_prison_set, 934 [PR_METHOD_GET] = shm_prison_get, 935 [PR_METHOD_REMOVE] = shm_prison_remove, 936 }; 937 938 #ifndef BURN_BRIDGES 939 if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0) 940 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n"); 941 #endif 942 if (shminfo.shmmax == SHMMAX) { 943 /* Initialize shmmax dealing with possible overflow. */ 944 for (i = PAGE_SIZE; i != 0; i--) { 945 shminfo.shmmax = shminfo.shmall * i; 946 if ((shminfo.shmmax / shminfo.shmall) == (u_long)i) 947 break; 948 } 949 } 950 shmalloced = shminfo.shmmni; 951 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, 952 M_WAITOK|M_ZERO); 953 for (i = 0; i < shmalloced; i++) { 954 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; 955 shmsegs[i].u.shm_perm.seq = 0; 956 #ifdef MAC 957 mac_sysvshm_init(&shmsegs[i]); 958 #endif 959 } 960 shm_last_free = 0; 961 shm_nused = 0; 962 shm_committed = 0; 963 sx_init(&sysvshmsx, "sysvshmsx"); 964 #ifndef SYSVSHM 965 shmexit_hook = &shmexit_myhook; 966 shmfork_hook = &shmfork_myhook; 967 #endif 968 969 /* Set current prisons according to their allow.sysvipc. */ 970 shm_prison_slot = osd_jail_register(NULL, methods); 971 rsv = osd_reserve(shm_prison_slot); 972 prison_lock(&prison0); 973 (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0); 974 prison_unlock(&prison0); 975 rsv = NULL; 976 sx_slock(&allprison_lock); 977 TAILQ_FOREACH(pr, &allprison, pr_list) { 978 if (rsv == NULL) 979 rsv = osd_reserve(shm_prison_slot); 980 prison_lock(pr); 981 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) { 982 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 983 &prison0); 984 rsv = NULL; 985 } 986 prison_unlock(pr); 987 } 988 if (rsv != NULL) 989 osd_free_reserved(rsv); 990 sx_sunlock(&allprison_lock); 991 992 error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD); 993 if (error != 0) 994 return (error); 995 #ifdef COMPAT_FREEBSD32 996 error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD); 997 if (error != 0) 998 return (error); 999 #endif 1000 return (0); 1001 } 1002 1003 static int 1004 shmunload(void) 1005 { 1006 int i; 1007 1008 if (shm_nused > 0) 1009 return (EBUSY); 1010 1011 #ifdef COMPAT_FREEBSD32 1012 syscall32_helper_unregister(shm32_syscalls); 1013 #endif 1014 syscall_helper_unregister(shm_syscalls); 1015 if (shm_prison_slot != 0) 1016 osd_jail_deregister(shm_prison_slot); 1017 1018 for (i = 0; i < shmalloced; i++) { 1019 #ifdef MAC 1020 mac_sysvshm_destroy(&shmsegs[i]); 1021 #endif 1022 /* 1023 * Objects might be still mapped into the processes 1024 * address spaces. Actual free would happen on the 1025 * last mapping destruction. 1026 */ 1027 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE) 1028 vm_object_deallocate(shmsegs[i].object); 1029 } 1030 free(shmsegs, M_SHM); 1031 #ifndef SYSVSHM 1032 shmexit_hook = NULL; 1033 shmfork_hook = NULL; 1034 #endif 1035 sx_destroy(&sysvshmsx); 1036 return (0); 1037 } 1038 1039 static int 1040 sysctl_shmsegs(SYSCTL_HANDLER_ARGS) 1041 { 1042 struct shmid_kernel tshmseg; 1043 #ifdef COMPAT_FREEBSD32 1044 struct shmid_kernel32 tshmseg32; 1045 #endif 1046 struct prison *pr, *rpr; 1047 void *outaddr; 1048 size_t outsize; 1049 int error, i; 1050 1051 SYSVSHM_LOCK(); 1052 pr = req->td->td_ucred->cr_prison; 1053 rpr = shm_find_prison(req->td->td_ucred); 1054 error = 0; 1055 for (i = 0; i < shmalloced; i++) { 1056 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 1057 rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) { 1058 bzero(&tshmseg, sizeof(tshmseg)); 1059 tshmseg.u.shm_perm.mode = SHMSEG_FREE; 1060 } else { 1061 tshmseg = shmsegs[i]; 1062 if (tshmseg.cred->cr_prison != pr) 1063 tshmseg.u.shm_perm.key = IPC_PRIVATE; 1064 } 1065 #ifdef COMPAT_FREEBSD32 1066 if (SV_CURPROC_FLAG(SV_ILP32)) { 1067 bzero(&tshmseg32, sizeof(tshmseg32)); 1068 freebsd32_ipcperm_out(&tshmseg.u.shm_perm, 1069 &tshmseg32.u.shm_perm); 1070 CP(tshmseg, tshmseg32, u.shm_segsz); 1071 CP(tshmseg, tshmseg32, u.shm_lpid); 1072 CP(tshmseg, tshmseg32, u.shm_cpid); 1073 CP(tshmseg, tshmseg32, u.shm_nattch); 1074 CP(tshmseg, tshmseg32, u.shm_atime); 1075 CP(tshmseg, tshmseg32, u.shm_dtime); 1076 CP(tshmseg, tshmseg32, u.shm_ctime); 1077 /* Don't copy object, label, or cred */ 1078 outaddr = &tshmseg32; 1079 outsize = sizeof(tshmseg32); 1080 } else 1081 #endif 1082 { 1083 tshmseg.object = NULL; 1084 tshmseg.label = NULL; 1085 tshmseg.cred = NULL; 1086 outaddr = &tshmseg; 1087 outsize = sizeof(tshmseg); 1088 } 1089 error = SYSCTL_OUT(req, outaddr, outsize); 1090 if (error != 0) 1091 break; 1092 } 1093 SYSVSHM_UNLOCK(); 1094 return (error); 1095 } 1096 1097 static int 1098 shm_prison_check(void *obj, void *data) 1099 { 1100 struct prison *pr = obj; 1101 struct prison *prpr; 1102 struct vfsoptlist *opts = data; 1103 int error, jsys; 1104 1105 /* 1106 * sysvshm is a jailsys integer. 1107 * It must be "disable" if the parent jail is disabled. 1108 */ 1109 error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1110 if (error != ENOENT) { 1111 if (error != 0) 1112 return (error); 1113 switch (jsys) { 1114 case JAIL_SYS_DISABLE: 1115 break; 1116 case JAIL_SYS_NEW: 1117 case JAIL_SYS_INHERIT: 1118 prison_lock(pr->pr_parent); 1119 prpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1120 prison_unlock(pr->pr_parent); 1121 if (prpr == NULL) 1122 return (EPERM); 1123 break; 1124 default: 1125 return (EINVAL); 1126 } 1127 } 1128 1129 return (0); 1130 } 1131 1132 static int 1133 shm_prison_set(void *obj, void *data) 1134 { 1135 struct prison *pr = obj; 1136 struct prison *tpr, *orpr, *nrpr, *trpr; 1137 struct vfsoptlist *opts = data; 1138 void *rsv; 1139 int jsys, descend; 1140 1141 /* 1142 * sysvshm controls which jail is the root of the associated segments 1143 * (this jail or same as the parent), or if the feature is available 1144 * at all. 1145 */ 1146 if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT) 1147 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0) 1148 ? JAIL_SYS_INHERIT 1149 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0) 1150 ? JAIL_SYS_DISABLE 1151 : -1; 1152 if (jsys == JAIL_SYS_DISABLE) { 1153 prison_lock(pr); 1154 orpr = osd_jail_get(pr, shm_prison_slot); 1155 if (orpr != NULL) 1156 osd_jail_del(pr, shm_prison_slot); 1157 prison_unlock(pr); 1158 if (orpr != NULL) { 1159 if (orpr == pr) 1160 shm_prison_cleanup(pr); 1161 /* Disable all child jails as well. */ 1162 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1163 prison_lock(tpr); 1164 trpr = osd_jail_get(tpr, shm_prison_slot); 1165 if (trpr != NULL) { 1166 osd_jail_del(tpr, shm_prison_slot); 1167 prison_unlock(tpr); 1168 if (trpr == tpr) 1169 shm_prison_cleanup(tpr); 1170 } else { 1171 prison_unlock(tpr); 1172 descend = 0; 1173 } 1174 } 1175 } 1176 } else if (jsys != -1) { 1177 if (jsys == JAIL_SYS_NEW) 1178 nrpr = pr; 1179 else { 1180 prison_lock(pr->pr_parent); 1181 nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1182 prison_unlock(pr->pr_parent); 1183 } 1184 rsv = osd_reserve(shm_prison_slot); 1185 prison_lock(pr); 1186 orpr = osd_jail_get(pr, shm_prison_slot); 1187 if (orpr != nrpr) 1188 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 1189 nrpr); 1190 else 1191 osd_free_reserved(rsv); 1192 prison_unlock(pr); 1193 if (orpr != nrpr) { 1194 if (orpr == pr) 1195 shm_prison_cleanup(pr); 1196 if (orpr != NULL) { 1197 /* Change child jails matching the old root, */ 1198 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1199 prison_lock(tpr); 1200 trpr = osd_jail_get(tpr, 1201 shm_prison_slot); 1202 if (trpr == orpr) { 1203 (void)osd_jail_set(tpr, 1204 shm_prison_slot, nrpr); 1205 prison_unlock(tpr); 1206 if (trpr == tpr) 1207 shm_prison_cleanup(tpr); 1208 } else { 1209 prison_unlock(tpr); 1210 descend = 0; 1211 } 1212 } 1213 } 1214 } 1215 } 1216 1217 return (0); 1218 } 1219 1220 static int 1221 shm_prison_get(void *obj, void *data) 1222 { 1223 struct prison *pr = obj; 1224 struct prison *rpr; 1225 struct vfsoptlist *opts = data; 1226 int error, jsys; 1227 1228 /* Set sysvshm based on the jail's root prison. */ 1229 prison_lock(pr); 1230 rpr = osd_jail_get(pr, shm_prison_slot); 1231 prison_unlock(pr); 1232 jsys = rpr == NULL ? JAIL_SYS_DISABLE 1233 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT; 1234 error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1235 if (error == ENOENT) 1236 error = 0; 1237 return (error); 1238 } 1239 1240 static int 1241 shm_prison_remove(void *obj, void *data __unused) 1242 { 1243 struct prison *pr = obj; 1244 struct prison *rpr; 1245 1246 SYSVSHM_LOCK(); 1247 prison_lock(pr); 1248 rpr = osd_jail_get(pr, shm_prison_slot); 1249 prison_unlock(pr); 1250 if (rpr == pr) 1251 shm_prison_cleanup(pr); 1252 SYSVSHM_UNLOCK(); 1253 return (0); 1254 } 1255 1256 static void 1257 shm_prison_cleanup(struct prison *pr) 1258 { 1259 struct shmid_kernel *shmseg; 1260 int i; 1261 1262 /* Remove any segments that belong to this jail. */ 1263 for (i = 0; i < shmalloced; i++) { 1264 shmseg = &shmsegs[i]; 1265 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) && 1266 shmseg->cred != NULL && shmseg->cred->cr_prison == pr) { 1267 shm_remove(shmseg, i); 1268 } 1269 } 1270 } 1271 1272 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory"); 1273 1274 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 1275 struct oshmid_ds { 1276 struct ipc_perm_old shm_perm; /* operation perms */ 1277 int shm_segsz; /* size of segment (bytes) */ 1278 u_short shm_cpid; /* pid, creator */ 1279 u_short shm_lpid; /* pid, last operation */ 1280 short shm_nattch; /* no. of current attaches */ 1281 time_t shm_atime; /* last attach time */ 1282 time_t shm_dtime; /* last detach time */ 1283 time_t shm_ctime; /* last change time */ 1284 void *shm_handle; /* internal handle for shm segment */ 1285 }; 1286 1287 struct oshmctl_args { 1288 int shmid; 1289 int cmd; 1290 struct oshmid_ds *ubuf; 1291 }; 1292 1293 static int 1294 oshmctl(struct thread *td, struct oshmctl_args *uap) 1295 { 1296 #ifdef COMPAT_43 1297 int error = 0; 1298 struct prison *rpr; 1299 struct shmid_kernel *shmseg; 1300 struct oshmid_ds outbuf; 1301 1302 rpr = shm_find_prison(td->td_ucred); 1303 if (rpr == NULL) 1304 return (ENOSYS); 1305 if (uap->cmd != IPC_STAT) { 1306 return (freebsd7_shmctl(td, 1307 (struct freebsd7_shmctl_args *)uap)); 1308 } 1309 SYSVSHM_LOCK(); 1310 shmseg = shm_find_segment(rpr, uap->shmid, true); 1311 if (shmseg == NULL) { 1312 SYSVSHM_UNLOCK(); 1313 return (EINVAL); 1314 } 1315 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 1316 if (error != 0) { 1317 SYSVSHM_UNLOCK(); 1318 return (error); 1319 } 1320 #ifdef MAC 1321 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd); 1322 if (error != 0) { 1323 SYSVSHM_UNLOCK(); 1324 return (error); 1325 } 1326 #endif 1327 ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm); 1328 outbuf.shm_segsz = shmseg->u.shm_segsz; 1329 outbuf.shm_cpid = shmseg->u.shm_cpid; 1330 outbuf.shm_lpid = shmseg->u.shm_lpid; 1331 outbuf.shm_nattch = shmseg->u.shm_nattch; 1332 outbuf.shm_atime = shmseg->u.shm_atime; 1333 outbuf.shm_dtime = shmseg->u.shm_dtime; 1334 outbuf.shm_ctime = shmseg->u.shm_ctime; 1335 outbuf.shm_handle = shmseg->object; 1336 SYSVSHM_UNLOCK(); 1337 return (copyout(&outbuf, uap->ubuf, sizeof(outbuf))); 1338 #else 1339 return (EINVAL); 1340 #endif 1341 } 1342 1343 /* XXX casting to (sy_call_t *) is bogus, as usual. */ 1344 static sy_call_t *shmcalls[] = { 1345 (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl, 1346 (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget, 1347 (sy_call_t *)freebsd7_shmctl 1348 }; 1349 1350 #ifndef _SYS_SYSPROTO_H_ 1351 /* XXX actually varargs. */ 1352 struct shmsys_args { 1353 int which; 1354 int a2; 1355 int a3; 1356 int a4; 1357 }; 1358 #endif 1359 int 1360 sys_shmsys(struct thread *td, struct shmsys_args *uap) 1361 { 1362 1363 AUDIT_ARG_SVIPC_WHICH(uap->which); 1364 if (uap->which < 0 || uap->which >= nitems(shmcalls)) 1365 return (EINVAL); 1366 return ((*shmcalls[uap->which])(td, &uap->a2)); 1367 } 1368 1369 #endif /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */ 1370 1371 #ifdef COMPAT_FREEBSD32 1372 1373 int 1374 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap) 1375 { 1376 1377 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1378 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1379 AUDIT_ARG_SVIPC_WHICH(uap->which); 1380 switch (uap->which) { 1381 case 0: { /* shmat */ 1382 struct shmat_args ap; 1383 1384 ap.shmid = uap->a2; 1385 ap.shmaddr = PTRIN(uap->a3); 1386 ap.shmflg = uap->a4; 1387 return (sysent[SYS_shmat].sy_call(td, &ap)); 1388 } 1389 case 2: { /* shmdt */ 1390 struct shmdt_args ap; 1391 1392 ap.shmaddr = PTRIN(uap->a2); 1393 return (sysent[SYS_shmdt].sy_call(td, &ap)); 1394 } 1395 case 3: { /* shmget */ 1396 struct shmget_args ap; 1397 1398 ap.key = uap->a2; 1399 ap.size = uap->a3; 1400 ap.shmflg = uap->a4; 1401 return (sysent[SYS_shmget].sy_call(td, &ap)); 1402 } 1403 case 4: { /* shmctl */ 1404 struct freebsd7_freebsd32_shmctl_args ap; 1405 1406 ap.shmid = uap->a2; 1407 ap.cmd = uap->a3; 1408 ap.buf = PTRIN(uap->a4); 1409 return (freebsd7_freebsd32_shmctl(td, &ap)); 1410 } 1411 case 1: /* oshmctl */ 1412 default: 1413 return (EINVAL); 1414 } 1415 #else 1416 return (nosys(td, NULL)); 1417 #endif 1418 } 1419 1420 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1421 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1422 int 1423 freebsd7_freebsd32_shmctl(struct thread *td, 1424 struct freebsd7_freebsd32_shmctl_args *uap) 1425 { 1426 int error; 1427 union { 1428 struct shmid_ds shmid_ds; 1429 struct shm_info shm_info; 1430 struct shminfo shminfo; 1431 } u; 1432 union { 1433 struct shmid_ds32_old shmid_ds32; 1434 struct shm_info32 shm_info32; 1435 struct shminfo32 shminfo32; 1436 } u32; 1437 size_t sz; 1438 1439 if (uap->cmd == IPC_SET) { 1440 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1441 sizeof(u32.shmid_ds32)))) 1442 goto done; 1443 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm, 1444 &u.shmid_ds.shm_perm); 1445 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1446 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1447 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1448 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1449 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1450 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1451 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1452 } 1453 1454 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1455 if (error) 1456 goto done; 1457 1458 /* Cases in which we need to copyout */ 1459 switch (uap->cmd) { 1460 case IPC_INFO: 1461 CP(u.shminfo, u32.shminfo32, shmmax); 1462 CP(u.shminfo, u32.shminfo32, shmmin); 1463 CP(u.shminfo, u32.shminfo32, shmmni); 1464 CP(u.shminfo, u32.shminfo32, shmseg); 1465 CP(u.shminfo, u32.shminfo32, shmall); 1466 error = copyout(&u32.shminfo32, uap->buf, 1467 sizeof(u32.shminfo32)); 1468 break; 1469 case SHM_INFO: 1470 CP(u.shm_info, u32.shm_info32, used_ids); 1471 CP(u.shm_info, u32.shm_info32, shm_rss); 1472 CP(u.shm_info, u32.shm_info32, shm_tot); 1473 CP(u.shm_info, u32.shm_info32, shm_swp); 1474 CP(u.shm_info, u32.shm_info32, swap_attempts); 1475 CP(u.shm_info, u32.shm_info32, swap_successes); 1476 error = copyout(&u32.shm_info32, uap->buf, 1477 sizeof(u32.shm_info32)); 1478 break; 1479 case SHM_STAT: 1480 case IPC_STAT: 1481 memset(&u32.shmid_ds32, 0, sizeof(u32.shmid_ds32)); 1482 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm, 1483 &u32.shmid_ds32.shm_perm); 1484 if (u.shmid_ds.shm_segsz > INT32_MAX) 1485 u32.shmid_ds32.shm_segsz = INT32_MAX; 1486 else 1487 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1488 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1489 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1490 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1491 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1492 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1493 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1494 u32.shmid_ds32.shm_internal = 0; 1495 error = copyout(&u32.shmid_ds32, uap->buf, 1496 sizeof(u32.shmid_ds32)); 1497 break; 1498 } 1499 1500 done: 1501 if (error) { 1502 /* Invalidate the return value */ 1503 td->td_retval[0] = -1; 1504 } 1505 return (error); 1506 } 1507 #endif 1508 1509 int 1510 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap) 1511 { 1512 int error; 1513 union { 1514 struct shmid_ds shmid_ds; 1515 struct shm_info shm_info; 1516 struct shminfo shminfo; 1517 } u; 1518 union { 1519 struct shmid_ds32 shmid_ds32; 1520 struct shm_info32 shm_info32; 1521 struct shminfo32 shminfo32; 1522 } u32; 1523 size_t sz; 1524 1525 if (uap->cmd == IPC_SET) { 1526 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1527 sizeof(u32.shmid_ds32)))) 1528 goto done; 1529 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm, 1530 &u.shmid_ds.shm_perm); 1531 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1532 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1533 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1534 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1535 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1536 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1537 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1538 } 1539 1540 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1541 if (error) 1542 goto done; 1543 1544 /* Cases in which we need to copyout */ 1545 switch (uap->cmd) { 1546 case IPC_INFO: 1547 CP(u.shminfo, u32.shminfo32, shmmax); 1548 CP(u.shminfo, u32.shminfo32, shmmin); 1549 CP(u.shminfo, u32.shminfo32, shmmni); 1550 CP(u.shminfo, u32.shminfo32, shmseg); 1551 CP(u.shminfo, u32.shminfo32, shmall); 1552 error = copyout(&u32.shminfo32, uap->buf, 1553 sizeof(u32.shminfo32)); 1554 break; 1555 case SHM_INFO: 1556 CP(u.shm_info, u32.shm_info32, used_ids); 1557 CP(u.shm_info, u32.shm_info32, shm_rss); 1558 CP(u.shm_info, u32.shm_info32, shm_tot); 1559 CP(u.shm_info, u32.shm_info32, shm_swp); 1560 CP(u.shm_info, u32.shm_info32, swap_attempts); 1561 CP(u.shm_info, u32.shm_info32, swap_successes); 1562 error = copyout(&u32.shm_info32, uap->buf, 1563 sizeof(u32.shm_info32)); 1564 break; 1565 case SHM_STAT: 1566 case IPC_STAT: 1567 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm, 1568 &u32.shmid_ds32.shm_perm); 1569 if (u.shmid_ds.shm_segsz > INT32_MAX) 1570 u32.shmid_ds32.shm_segsz = INT32_MAX; 1571 else 1572 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1573 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1574 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1575 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1576 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1577 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1578 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1579 error = copyout(&u32.shmid_ds32, uap->buf, 1580 sizeof(u32.shmid_ds32)); 1581 break; 1582 } 1583 1584 done: 1585 if (error) { 1586 /* Invalidate the return value */ 1587 td->td_retval[0] = -1; 1588 } 1589 return (error); 1590 } 1591 #endif 1592 1593 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1594 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1595 1596 #ifndef CP 1597 #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0) 1598 #endif 1599 1600 #ifndef _SYS_SYSPROTO_H_ 1601 struct freebsd7_shmctl_args { 1602 int shmid; 1603 int cmd; 1604 struct shmid_ds_old *buf; 1605 }; 1606 #endif 1607 int 1608 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap) 1609 { 1610 int error; 1611 struct shmid_ds_old old; 1612 struct shmid_ds buf; 1613 size_t bufsz; 1614 1615 /* 1616 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 1617 * Linux binaries. If we see the call come through the FreeBSD ABI, 1618 * return an error back to the user since we do not to support this. 1619 */ 1620 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 1621 uap->cmd == SHM_STAT) 1622 return (EINVAL); 1623 1624 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 1625 if (uap->cmd == IPC_SET) { 1626 if ((error = copyin(uap->buf, &old, sizeof(old)))) 1627 goto done; 1628 ipcperm_old2new(&old.shm_perm, &buf.shm_perm); 1629 CP(old, buf, shm_segsz); 1630 CP(old, buf, shm_lpid); 1631 CP(old, buf, shm_cpid); 1632 CP(old, buf, shm_nattch); 1633 CP(old, buf, shm_atime); 1634 CP(old, buf, shm_dtime); 1635 CP(old, buf, shm_ctime); 1636 } 1637 1638 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 1639 if (error) 1640 goto done; 1641 1642 /* Cases in which we need to copyout */ 1643 switch (uap->cmd) { 1644 case IPC_STAT: 1645 memset(&old, 0, sizeof(old)); 1646 ipcperm_new2old(&buf.shm_perm, &old.shm_perm); 1647 if (buf.shm_segsz > INT_MAX) 1648 old.shm_segsz = INT_MAX; 1649 else 1650 CP(buf, old, shm_segsz); 1651 CP(buf, old, shm_lpid); 1652 CP(buf, old, shm_cpid); 1653 if (buf.shm_nattch > SHRT_MAX) 1654 old.shm_nattch = SHRT_MAX; 1655 else 1656 CP(buf, old, shm_nattch); 1657 CP(buf, old, shm_atime); 1658 CP(buf, old, shm_dtime); 1659 CP(buf, old, shm_ctime); 1660 old.shm_internal = NULL; 1661 error = copyout(&old, uap->buf, sizeof(old)); 1662 break; 1663 } 1664 1665 done: 1666 if (error) { 1667 /* Invalidate the return value */ 1668 td->td_retval[0] = -1; 1669 } 1670 return (error); 1671 } 1672 1673 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || 1674 COMPAT_FREEBSD7 */ 1675 1676 static int 1677 sysvshm_modload(struct module *module, int cmd, void *arg) 1678 { 1679 int error = 0; 1680 1681 switch (cmd) { 1682 case MOD_LOAD: 1683 error = shminit(); 1684 if (error != 0) 1685 shmunload(); 1686 break; 1687 case MOD_UNLOAD: 1688 error = shmunload(); 1689 break; 1690 case MOD_SHUTDOWN: 1691 break; 1692 default: 1693 error = EINVAL; 1694 break; 1695 } 1696 return (error); 1697 } 1698 1699 static moduledata_t sysvshm_mod = { 1700 "sysvshm", 1701 &sysvshm_modload, 1702 NULL 1703 }; 1704 1705 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST); 1706 MODULE_VERSION(sysvshm, 1); 1707