Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/sysv_shm.c
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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: releng/12.0/sys/kern/sysv_shm.c 332122 2018-04-06 17:35:35Z brooks $"); 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 #if defined(AUDIT) || defined(MAC) 336 struct shmid_kernel *shmsegptr; 337 #endif 338 #ifdef MAC 339 int error; 340 #endif 341 int i; 342 343 SYSVSHM_ASSERT_LOCKED(); 344 if (shm_find_prison(td->td_ucred) == NULL) 345 return (ENOSYS); 346 shmmap_s = p->p_vmspace->vm_shm; 347 if (shmmap_s == NULL) 348 return (EINVAL); 349 AUDIT_ARG_SVIPC_ID(shmmap_s->shmid); 350 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 351 if (shmmap_s->shmid != -1 && 352 shmmap_s->va == (vm_offset_t)shmaddr) { 353 break; 354 } 355 } 356 if (i == shminfo.shmseg) 357 return (EINVAL); 358 #if (defined(AUDIT) && defined(KDTRACE_HOOKS)) || defined(MAC) 359 shmsegptr = &shmsegs[IPCID_TO_IX(shmmap_s->shmid)]; 360 #endif 361 #ifdef MAC 362 error = mac_sysvshm_check_shmdt(td->td_ucred, shmsegptr); 363 if (error != 0) 364 return (error); 365 #endif 366 return (shm_delete_mapping(p->p_vmspace, shmmap_s)); 367 } 368 369 #ifndef _SYS_SYSPROTO_H_ 370 struct shmdt_args { 371 const void *shmaddr; 372 }; 373 #endif 374 int 375 sys_shmdt(struct thread *td, struct shmdt_args *uap) 376 { 377 int error; 378 379 SYSVSHM_LOCK(); 380 error = kern_shmdt_locked(td, uap->shmaddr); 381 SYSVSHM_UNLOCK(); 382 return (error); 383 } 384 385 static int 386 kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr, 387 int shmflg) 388 { 389 struct prison *rpr; 390 struct proc *p = td->td_proc; 391 struct shmid_kernel *shmseg; 392 struct shmmap_state *shmmap_s; 393 vm_offset_t attach_va; 394 vm_prot_t prot; 395 vm_size_t size; 396 int error, i, rv; 397 398 AUDIT_ARG_SVIPC_ID(shmid); 399 AUDIT_ARG_VALUE(shmflg); 400 401 SYSVSHM_ASSERT_LOCKED(); 402 rpr = shm_find_prison(td->td_ucred); 403 if (rpr == NULL) 404 return (ENOSYS); 405 shmmap_s = p->p_vmspace->vm_shm; 406 if (shmmap_s == NULL) { 407 shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state), 408 M_SHM, M_WAITOK); 409 for (i = 0; i < shminfo.shmseg; i++) 410 shmmap_s[i].shmid = -1; 411 KASSERT(p->p_vmspace->vm_shm == NULL, ("raced")); 412 p->p_vmspace->vm_shm = shmmap_s; 413 } 414 shmseg = shm_find_segment(rpr, shmid, true); 415 if (shmseg == NULL) 416 return (EINVAL); 417 error = ipcperm(td, &shmseg->u.shm_perm, 418 (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); 419 if (error != 0) 420 return (error); 421 #ifdef MAC 422 error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg); 423 if (error != 0) 424 return (error); 425 #endif 426 for (i = 0; i < shminfo.shmseg; i++) { 427 if (shmmap_s->shmid == -1) 428 break; 429 shmmap_s++; 430 } 431 if (i >= shminfo.shmseg) 432 return (EMFILE); 433 size = round_page(shmseg->u.shm_segsz); 434 prot = VM_PROT_READ; 435 if ((shmflg & SHM_RDONLY) == 0) 436 prot |= VM_PROT_WRITE; 437 if (shmaddr != NULL) { 438 if ((shmflg & SHM_RND) != 0) 439 attach_va = rounddown2((vm_offset_t)shmaddr, SHMLBA); 440 else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0) 441 attach_va = (vm_offset_t)shmaddr; 442 else 443 return (EINVAL); 444 } else { 445 /* 446 * This is just a hint to vm_map_find() about where to 447 * put it. 448 */ 449 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr + 450 lim_max(td, RLIMIT_DATA)); 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, shmaddr != NULL ? VMFS_NO_SPACE : VMFS_OPTIMAL_SPACE, 456 prot, prot, MAP_INHERIT_SHARE | MAP_PREFAULT_PARTIAL); 457 if (rv != KERN_SUCCESS) { 458 vm_object_deallocate(shmseg->object); 459 return (ENOMEM); 460 } 461 462 shmmap_s->va = attach_va; 463 shmmap_s->shmid = shmid; 464 shmseg->u.shm_lpid = p->p_pid; 465 shmseg->u.shm_atime = time_second; 466 shmseg->u.shm_nattch++; 467 td->td_retval[0] = attach_va; 468 return (error); 469 } 470 471 int 472 kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg) 473 { 474 int error; 475 476 SYSVSHM_LOCK(); 477 error = kern_shmat_locked(td, shmid, shmaddr, shmflg); 478 SYSVSHM_UNLOCK(); 479 return (error); 480 } 481 482 #ifndef _SYS_SYSPROTO_H_ 483 struct shmat_args { 484 int shmid; 485 const void *shmaddr; 486 int shmflg; 487 }; 488 #endif 489 int 490 sys_shmat(struct thread *td, struct shmat_args *uap) 491 { 492 493 return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg)); 494 } 495 496 static int 497 kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf, 498 size_t *bufsz) 499 { 500 struct prison *rpr; 501 struct shmid_kernel *shmseg; 502 struct shmid_ds *shmidp; 503 struct shm_info shm_info; 504 int error; 505 506 SYSVSHM_ASSERT_LOCKED(); 507 508 rpr = shm_find_prison(td->td_ucred); 509 if (rpr == NULL) 510 return (ENOSYS); 511 512 AUDIT_ARG_SVIPC_ID(shmid); 513 AUDIT_ARG_SVIPC_CMD(cmd); 514 515 switch (cmd) { 516 /* 517 * It is possible that kern_shmctl is being called from the Linux ABI 518 * layer, in which case, we will need to implement IPC_INFO. It should 519 * be noted that other shmctl calls will be funneled through here for 520 * Linix binaries as well. 521 * 522 * NB: The Linux ABI layer will convert this data to structure(s) more 523 * consistent with the Linux ABI. 524 */ 525 case IPC_INFO: 526 memcpy(buf, &shminfo, sizeof(shminfo)); 527 if (bufsz) 528 *bufsz = sizeof(shminfo); 529 td->td_retval[0] = shmalloced; 530 return (0); 531 case SHM_INFO: { 532 shm_info.used_ids = shm_nused; 533 shm_info.shm_rss = 0; /*XXX where to get from ? */ 534 shm_info.shm_tot = 0; /*XXX where to get from ? */ 535 shm_info.shm_swp = 0; /*XXX where to get from ? */ 536 shm_info.swap_attempts = 0; /*XXX where to get from ? */ 537 shm_info.swap_successes = 0; /*XXX where to get from ? */ 538 memcpy(buf, &shm_info, sizeof(shm_info)); 539 if (bufsz != NULL) 540 *bufsz = sizeof(shm_info); 541 td->td_retval[0] = shmalloced; 542 return (0); 543 } 544 } 545 shmseg = shm_find_segment(rpr, shmid, cmd != SHM_STAT); 546 if (shmseg == NULL) 547 return (EINVAL); 548 #ifdef MAC 549 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd); 550 if (error != 0) 551 return (error); 552 #endif 553 switch (cmd) { 554 case SHM_STAT: 555 case IPC_STAT: 556 shmidp = (struct shmid_ds *)buf; 557 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 558 if (error != 0) 559 return (error); 560 memcpy(shmidp, &shmseg->u, sizeof(struct shmid_ds)); 561 if (td->td_ucred->cr_prison != shmseg->cred->cr_prison) 562 shmidp->shm_perm.key = IPC_PRIVATE; 563 if (bufsz != NULL) 564 *bufsz = sizeof(struct shmid_ds); 565 if (cmd == SHM_STAT) { 566 td->td_retval[0] = IXSEQ_TO_IPCID(shmid, 567 shmseg->u.shm_perm); 568 } 569 break; 570 case IPC_SET: 571 shmidp = (struct shmid_ds *)buf; 572 AUDIT_ARG_SVIPC_PERM(&shmidp->shm_perm); 573 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); 574 if (error != 0) 575 return (error); 576 shmseg->u.shm_perm.uid = shmidp->shm_perm.uid; 577 shmseg->u.shm_perm.gid = shmidp->shm_perm.gid; 578 shmseg->u.shm_perm.mode = 579 (shmseg->u.shm_perm.mode & ~ACCESSPERMS) | 580 (shmidp->shm_perm.mode & ACCESSPERMS); 581 shmseg->u.shm_ctime = time_second; 582 break; 583 case IPC_RMID: 584 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); 585 if (error != 0) 586 return (error); 587 shm_remove(shmseg, IPCID_TO_IX(shmid)); 588 break; 589 #if 0 590 case SHM_LOCK: 591 case SHM_UNLOCK: 592 #endif 593 default: 594 error = EINVAL; 595 break; 596 } 597 return (error); 598 } 599 600 int 601 kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz) 602 { 603 int error; 604 605 SYSVSHM_LOCK(); 606 error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz); 607 SYSVSHM_UNLOCK(); 608 return (error); 609 } 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 } 659 660 661 static int 662 shmget_existing(struct thread *td, struct shmget_args *uap, int mode, 663 int segnum) 664 { 665 struct shmid_kernel *shmseg; 666 #ifdef MAC 667 int error; 668 #endif 669 670 SYSVSHM_ASSERT_LOCKED(); 671 KASSERT(segnum >= 0 && segnum < shmalloced, 672 ("segnum %d shmalloced %d", segnum, shmalloced)); 673 shmseg = &shmsegs[segnum]; 674 if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) 675 return (EEXIST); 676 #ifdef MAC 677 error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg); 678 if (error != 0) 679 return (error); 680 #endif 681 if (uap->size != 0 && uap->size > shmseg->u.shm_segsz) 682 return (EINVAL); 683 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 684 return (0); 685 } 686 687 static int 688 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode) 689 { 690 struct ucred *cred = td->td_ucred; 691 struct shmid_kernel *shmseg; 692 vm_object_t shm_object; 693 int i, segnum; 694 size_t size; 695 696 SYSVSHM_ASSERT_LOCKED(); 697 698 if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) 699 return (EINVAL); 700 if (shm_nused >= shminfo.shmmni) /* Any shmids left? */ 701 return (ENOSPC); 702 size = round_page(uap->size); 703 if (shm_committed + btoc(size) > shminfo.shmall) 704 return (ENOMEM); 705 if (shm_last_free < 0) { 706 shmrealloc(); /* Maybe expand the shmsegs[] array. */ 707 for (i = 0; i < shmalloced; i++) 708 if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE) 709 break; 710 if (i == shmalloced) 711 return (ENOSPC); 712 segnum = i; 713 } else { 714 segnum = shm_last_free; 715 shm_last_free = -1; 716 } 717 KASSERT(segnum >= 0 && segnum < shmalloced, 718 ("segnum %d shmalloced %d", segnum, shmalloced)); 719 shmseg = &shmsegs[segnum]; 720 #ifdef RACCT 721 if (racct_enable) { 722 PROC_LOCK(td->td_proc); 723 if (racct_add(td->td_proc, RACCT_NSHM, 1)) { 724 PROC_UNLOCK(td->td_proc); 725 return (ENOSPC); 726 } 727 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) { 728 racct_sub(td->td_proc, RACCT_NSHM, 1); 729 PROC_UNLOCK(td->td_proc); 730 return (ENOMEM); 731 } 732 PROC_UNLOCK(td->td_proc); 733 } 734 #endif 735 736 /* 737 * We make sure that we have allocated a pager before we need 738 * to. 739 */ 740 shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP, 741 0, size, VM_PROT_DEFAULT, 0, cred); 742 if (shm_object == NULL) { 743 #ifdef RACCT 744 if (racct_enable) { 745 PROC_LOCK(td->td_proc); 746 racct_sub(td->td_proc, RACCT_NSHM, 1); 747 racct_sub(td->td_proc, RACCT_SHMSIZE, size); 748 PROC_UNLOCK(td->td_proc); 749 } 750 #endif 751 return (ENOMEM); 752 } 753 shm_object->pg_color = 0; 754 VM_OBJECT_WLOCK(shm_object); 755 vm_object_clear_flag(shm_object, OBJ_ONEMAPPING); 756 vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT); 757 VM_OBJECT_WUNLOCK(shm_object); 758 759 shmseg->object = shm_object; 760 shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid; 761 shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid; 762 shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; 763 shmseg->u.shm_perm.key = uap->key; 764 shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff; 765 shmseg->cred = crhold(cred); 766 shmseg->u.shm_segsz = uap->size; 767 shmseg->u.shm_cpid = td->td_proc->p_pid; 768 shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0; 769 shmseg->u.shm_atime = shmseg->u.shm_dtime = 0; 770 #ifdef MAC 771 mac_sysvshm_create(cred, shmseg); 772 #endif 773 shmseg->u.shm_ctime = time_second; 774 shm_committed += btoc(size); 775 shm_nused++; 776 td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); 777 778 return (0); 779 } 780 781 #ifndef _SYS_SYSPROTO_H_ 782 struct shmget_args { 783 key_t key; 784 size_t size; 785 int shmflg; 786 }; 787 #endif 788 int 789 sys_shmget(struct thread *td, struct shmget_args *uap) 790 { 791 int segnum, mode; 792 int error; 793 794 if (shm_find_prison(td->td_ucred) == NULL) 795 return (ENOSYS); 796 mode = uap->shmflg & ACCESSPERMS; 797 SYSVSHM_LOCK(); 798 if (uap->key == IPC_PRIVATE) { 799 error = shmget_allocate_segment(td, uap, mode); 800 } else { 801 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison, 802 uap->key); 803 if (segnum >= 0) 804 error = shmget_existing(td, uap, mode, segnum); 805 else if ((uap->shmflg & IPC_CREAT) == 0) 806 error = ENOENT; 807 else 808 error = shmget_allocate_segment(td, uap, mode); 809 } 810 SYSVSHM_UNLOCK(); 811 return (error); 812 } 813 814 static void 815 shmfork_myhook(struct proc *p1, struct proc *p2) 816 { 817 struct shmmap_state *shmmap_s; 818 size_t size; 819 int i; 820 821 SYSVSHM_LOCK(); 822 size = shminfo.shmseg * sizeof(struct shmmap_state); 823 shmmap_s = malloc(size, M_SHM, M_WAITOK); 824 bcopy(p1->p_vmspace->vm_shm, shmmap_s, size); 825 p2->p_vmspace->vm_shm = shmmap_s; 826 for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { 827 if (shmmap_s->shmid != -1) { 828 KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 && 829 IPCID_TO_IX(shmmap_s->shmid) < shmalloced, 830 ("segnum %d shmalloced %d", 831 IPCID_TO_IX(shmmap_s->shmid), shmalloced)); 832 shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++; 833 } 834 } 835 SYSVSHM_UNLOCK(); 836 } 837 838 static void 839 shmexit_myhook(struct vmspace *vm) 840 { 841 struct shmmap_state *base, *shm; 842 int i; 843 844 base = vm->vm_shm; 845 if (base != NULL) { 846 vm->vm_shm = NULL; 847 SYSVSHM_LOCK(); 848 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) { 849 if (shm->shmid != -1) 850 shm_delete_mapping(vm, shm); 851 } 852 SYSVSHM_UNLOCK(); 853 free(base, M_SHM); 854 } 855 } 856 857 static void 858 shmrealloc(void) 859 { 860 struct shmid_kernel *newsegs; 861 int i; 862 863 SYSVSHM_ASSERT_LOCKED(); 864 865 if (shmalloced >= shminfo.shmmni) 866 return; 867 868 newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, 869 M_WAITOK | M_ZERO); 870 for (i = 0; i < shmalloced; i++) 871 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); 872 for (; i < shminfo.shmmni; i++) { 873 newsegs[i].u.shm_perm.mode = SHMSEG_FREE; 874 newsegs[i].u.shm_perm.seq = 0; 875 #ifdef MAC 876 mac_sysvshm_init(&newsegs[i]); 877 #endif 878 } 879 free(shmsegs, M_SHM); 880 shmsegs = newsegs; 881 shmalloced = shminfo.shmmni; 882 } 883 884 static struct syscall_helper_data shm_syscalls[] = { 885 SYSCALL_INIT_HELPER(shmat), 886 SYSCALL_INIT_HELPER(shmctl), 887 SYSCALL_INIT_HELPER(shmdt), 888 SYSCALL_INIT_HELPER(shmget), 889 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 890 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 891 SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl), 892 #endif 893 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 894 SYSCALL_INIT_HELPER(shmsys), 895 #endif 896 SYSCALL_INIT_LAST 897 }; 898 899 #ifdef COMPAT_FREEBSD32 900 #include <compat/freebsd32/freebsd32.h> 901 #include <compat/freebsd32/freebsd32_ipc.h> 902 #include <compat/freebsd32/freebsd32_proto.h> 903 #include <compat/freebsd32/freebsd32_signal.h> 904 #include <compat/freebsd32/freebsd32_syscall.h> 905 #include <compat/freebsd32/freebsd32_util.h> 906 907 static struct syscall_helper_data shm32_syscalls[] = { 908 SYSCALL32_INIT_HELPER_COMPAT(shmat), 909 SYSCALL32_INIT_HELPER_COMPAT(shmdt), 910 SYSCALL32_INIT_HELPER_COMPAT(shmget), 911 SYSCALL32_INIT_HELPER(freebsd32_shmsys), 912 SYSCALL32_INIT_HELPER(freebsd32_shmctl), 913 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 914 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 915 SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl), 916 #endif 917 SYSCALL_INIT_LAST 918 }; 919 #endif 920 921 static int 922 shminit(void) 923 { 924 struct prison *pr; 925 void **rsv; 926 int i, error; 927 osd_method_t methods[PR_MAXMETHOD] = { 928 [PR_METHOD_CHECK] = shm_prison_check, 929 [PR_METHOD_SET] = shm_prison_set, 930 [PR_METHOD_GET] = shm_prison_get, 931 [PR_METHOD_REMOVE] = shm_prison_remove, 932 }; 933 934 #ifndef BURN_BRIDGES 935 if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0) 936 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n"); 937 #endif 938 if (shminfo.shmmax == SHMMAX) { 939 /* Initialize shmmax dealing with possible overflow. */ 940 for (i = PAGE_SIZE; i != 0; i--) { 941 shminfo.shmmax = shminfo.shmall * i; 942 if ((shminfo.shmmax / shminfo.shmall) == (u_long)i) 943 break; 944 } 945 } 946 shmalloced = shminfo.shmmni; 947 shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, 948 M_WAITOK|M_ZERO); 949 for (i = 0; i < shmalloced; i++) { 950 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; 951 shmsegs[i].u.shm_perm.seq = 0; 952 #ifdef MAC 953 mac_sysvshm_init(&shmsegs[i]); 954 #endif 955 } 956 shm_last_free = 0; 957 shm_nused = 0; 958 shm_committed = 0; 959 sx_init(&sysvshmsx, "sysvshmsx"); 960 shmexit_hook = &shmexit_myhook; 961 shmfork_hook = &shmfork_myhook; 962 963 /* Set current prisons according to their allow.sysvipc. */ 964 shm_prison_slot = osd_jail_register(NULL, methods); 965 rsv = osd_reserve(shm_prison_slot); 966 prison_lock(&prison0); 967 (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0); 968 prison_unlock(&prison0); 969 rsv = NULL; 970 sx_slock(&allprison_lock); 971 TAILQ_FOREACH(pr, &allprison, pr_list) { 972 if (rsv == NULL) 973 rsv = osd_reserve(shm_prison_slot); 974 prison_lock(pr); 975 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) { 976 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 977 &prison0); 978 rsv = NULL; 979 } 980 prison_unlock(pr); 981 } 982 if (rsv != NULL) 983 osd_free_reserved(rsv); 984 sx_sunlock(&allprison_lock); 985 986 error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD); 987 if (error != 0) 988 return (error); 989 #ifdef COMPAT_FREEBSD32 990 error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD); 991 if (error != 0) 992 return (error); 993 #endif 994 return (0); 995 } 996 997 static int 998 shmunload(void) 999 { 1000 int i; 1001 1002 if (shm_nused > 0) 1003 return (EBUSY); 1004 1005 #ifdef COMPAT_FREEBSD32 1006 syscall32_helper_unregister(shm32_syscalls); 1007 #endif 1008 syscall_helper_unregister(shm_syscalls); 1009 if (shm_prison_slot != 0) 1010 osd_jail_deregister(shm_prison_slot); 1011 1012 for (i = 0; i < shmalloced; i++) { 1013 #ifdef MAC 1014 mac_sysvshm_destroy(&shmsegs[i]); 1015 #endif 1016 /* 1017 * Objects might be still mapped into the processes 1018 * address spaces. Actual free would happen on the 1019 * last mapping destruction. 1020 */ 1021 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE) 1022 vm_object_deallocate(shmsegs[i].object); 1023 } 1024 free(shmsegs, M_SHM); 1025 shmexit_hook = NULL; 1026 shmfork_hook = NULL; 1027 sx_destroy(&sysvshmsx); 1028 return (0); 1029 } 1030 1031 static int 1032 sysctl_shmsegs(SYSCTL_HANDLER_ARGS) 1033 { 1034 struct shmid_kernel tshmseg; 1035 #ifdef COMPAT_FREEBSD32 1036 struct shmid_kernel32 tshmseg32; 1037 #endif 1038 struct prison *pr, *rpr; 1039 void *outaddr; 1040 size_t outsize; 1041 int error, i; 1042 1043 SYSVSHM_LOCK(); 1044 pr = req->td->td_ucred->cr_prison; 1045 rpr = shm_find_prison(req->td->td_ucred); 1046 error = 0; 1047 for (i = 0; i < shmalloced; i++) { 1048 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || 1049 rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) { 1050 bzero(&tshmseg, sizeof(tshmseg)); 1051 tshmseg.u.shm_perm.mode = SHMSEG_FREE; 1052 } else { 1053 tshmseg = shmsegs[i]; 1054 if (tshmseg.cred->cr_prison != pr) 1055 tshmseg.u.shm_perm.key = IPC_PRIVATE; 1056 } 1057 #ifdef COMPAT_FREEBSD32 1058 if (SV_CURPROC_FLAG(SV_ILP32)) { 1059 bzero(&tshmseg32, sizeof(tshmseg32)); 1060 freebsd32_ipcperm_out(&tshmseg.u.shm_perm, 1061 &tshmseg32.u.shm_perm); 1062 CP(tshmseg, tshmseg32, u.shm_segsz); 1063 CP(tshmseg, tshmseg32, u.shm_lpid); 1064 CP(tshmseg, tshmseg32, u.shm_cpid); 1065 CP(tshmseg, tshmseg32, u.shm_nattch); 1066 CP(tshmseg, tshmseg32, u.shm_atime); 1067 CP(tshmseg, tshmseg32, u.shm_dtime); 1068 CP(tshmseg, tshmseg32, u.shm_ctime); 1069 /* Don't copy object, label, or cred */ 1070 outaddr = &tshmseg32; 1071 outsize = sizeof(tshmseg32); 1072 } else 1073 #endif 1074 { 1075 tshmseg.object = NULL; 1076 tshmseg.label = NULL; 1077 tshmseg.cred = NULL; 1078 outaddr = &tshmseg; 1079 outsize = sizeof(tshmseg); 1080 } 1081 error = SYSCTL_OUT(req, outaddr, outsize); 1082 if (error != 0) 1083 break; 1084 } 1085 SYSVSHM_UNLOCK(); 1086 return (error); 1087 } 1088 1089 static int 1090 shm_prison_check(void *obj, void *data) 1091 { 1092 struct prison *pr = obj; 1093 struct prison *prpr; 1094 struct vfsoptlist *opts = data; 1095 int error, jsys; 1096 1097 /* 1098 * sysvshm is a jailsys integer. 1099 * It must be "disable" if the parent jail is disabled. 1100 */ 1101 error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1102 if (error != ENOENT) { 1103 if (error != 0) 1104 return (error); 1105 switch (jsys) { 1106 case JAIL_SYS_DISABLE: 1107 break; 1108 case JAIL_SYS_NEW: 1109 case JAIL_SYS_INHERIT: 1110 prison_lock(pr->pr_parent); 1111 prpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1112 prison_unlock(pr->pr_parent); 1113 if (prpr == NULL) 1114 return (EPERM); 1115 break; 1116 default: 1117 return (EINVAL); 1118 } 1119 } 1120 1121 return (0); 1122 } 1123 1124 static int 1125 shm_prison_set(void *obj, void *data) 1126 { 1127 struct prison *pr = obj; 1128 struct prison *tpr, *orpr, *nrpr, *trpr; 1129 struct vfsoptlist *opts = data; 1130 void *rsv; 1131 int jsys, descend; 1132 1133 /* 1134 * sysvshm controls which jail is the root of the associated segments 1135 * (this jail or same as the parent), or if the feature is available 1136 * at all. 1137 */ 1138 if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT) 1139 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0) 1140 ? JAIL_SYS_INHERIT 1141 : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0) 1142 ? JAIL_SYS_DISABLE 1143 : -1; 1144 if (jsys == JAIL_SYS_DISABLE) { 1145 prison_lock(pr); 1146 orpr = osd_jail_get(pr, shm_prison_slot); 1147 if (orpr != NULL) 1148 osd_jail_del(pr, shm_prison_slot); 1149 prison_unlock(pr); 1150 if (orpr != NULL) { 1151 if (orpr == pr) 1152 shm_prison_cleanup(pr); 1153 /* Disable all child jails as well. */ 1154 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1155 prison_lock(tpr); 1156 trpr = osd_jail_get(tpr, shm_prison_slot); 1157 if (trpr != NULL) { 1158 osd_jail_del(tpr, shm_prison_slot); 1159 prison_unlock(tpr); 1160 if (trpr == tpr) 1161 shm_prison_cleanup(tpr); 1162 } else { 1163 prison_unlock(tpr); 1164 descend = 0; 1165 } 1166 } 1167 } 1168 } else if (jsys != -1) { 1169 if (jsys == JAIL_SYS_NEW) 1170 nrpr = pr; 1171 else { 1172 prison_lock(pr->pr_parent); 1173 nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot); 1174 prison_unlock(pr->pr_parent); 1175 } 1176 rsv = osd_reserve(shm_prison_slot); 1177 prison_lock(pr); 1178 orpr = osd_jail_get(pr, shm_prison_slot); 1179 if (orpr != nrpr) 1180 (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv, 1181 nrpr); 1182 else 1183 osd_free_reserved(rsv); 1184 prison_unlock(pr); 1185 if (orpr != nrpr) { 1186 if (orpr == pr) 1187 shm_prison_cleanup(pr); 1188 if (orpr != NULL) { 1189 /* Change child jails matching the old root, */ 1190 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) { 1191 prison_lock(tpr); 1192 trpr = osd_jail_get(tpr, 1193 shm_prison_slot); 1194 if (trpr == orpr) { 1195 (void)osd_jail_set(tpr, 1196 shm_prison_slot, nrpr); 1197 prison_unlock(tpr); 1198 if (trpr == tpr) 1199 shm_prison_cleanup(tpr); 1200 } else { 1201 prison_unlock(tpr); 1202 descend = 0; 1203 } 1204 } 1205 } 1206 } 1207 } 1208 1209 return (0); 1210 } 1211 1212 static int 1213 shm_prison_get(void *obj, void *data) 1214 { 1215 struct prison *pr = obj; 1216 struct prison *rpr; 1217 struct vfsoptlist *opts = data; 1218 int error, jsys; 1219 1220 /* Set sysvshm based on the jail's root prison. */ 1221 prison_lock(pr); 1222 rpr = osd_jail_get(pr, shm_prison_slot); 1223 prison_unlock(pr); 1224 jsys = rpr == NULL ? JAIL_SYS_DISABLE 1225 : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT; 1226 error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys)); 1227 if (error == ENOENT) 1228 error = 0; 1229 return (error); 1230 } 1231 1232 static int 1233 shm_prison_remove(void *obj, void *data __unused) 1234 { 1235 struct prison *pr = obj; 1236 struct prison *rpr; 1237 1238 SYSVSHM_LOCK(); 1239 prison_lock(pr); 1240 rpr = osd_jail_get(pr, shm_prison_slot); 1241 prison_unlock(pr); 1242 if (rpr == pr) 1243 shm_prison_cleanup(pr); 1244 SYSVSHM_UNLOCK(); 1245 return (0); 1246 } 1247 1248 static void 1249 shm_prison_cleanup(struct prison *pr) 1250 { 1251 struct shmid_kernel *shmseg; 1252 int i; 1253 1254 /* Remove any segments that belong to this jail. */ 1255 for (i = 0; i < shmalloced; i++) { 1256 shmseg = &shmsegs[i]; 1257 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) && 1258 shmseg->cred != NULL && shmseg->cred->cr_prison == pr) { 1259 shm_remove(shmseg, i); 1260 } 1261 } 1262 } 1263 1264 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory"); 1265 1266 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) 1267 struct oshmid_ds { 1268 struct ipc_perm_old shm_perm; /* operation perms */ 1269 int shm_segsz; /* size of segment (bytes) */ 1270 u_short shm_cpid; /* pid, creator */ 1271 u_short shm_lpid; /* pid, last operation */ 1272 short shm_nattch; /* no. of current attaches */ 1273 time_t shm_atime; /* last attach time */ 1274 time_t shm_dtime; /* last detach time */ 1275 time_t shm_ctime; /* last change time */ 1276 void *shm_handle; /* internal handle for shm segment */ 1277 }; 1278 1279 struct oshmctl_args { 1280 int shmid; 1281 int cmd; 1282 struct oshmid_ds *ubuf; 1283 }; 1284 1285 static int 1286 oshmctl(struct thread *td, struct oshmctl_args *uap) 1287 { 1288 #ifdef COMPAT_43 1289 int error = 0; 1290 struct prison *rpr; 1291 struct shmid_kernel *shmseg; 1292 struct oshmid_ds outbuf; 1293 1294 rpr = shm_find_prison(td->td_ucred); 1295 if (rpr == NULL) 1296 return (ENOSYS); 1297 if (uap->cmd != IPC_STAT) { 1298 return (freebsd7_shmctl(td, 1299 (struct freebsd7_shmctl_args *)uap)); 1300 } 1301 SYSVSHM_LOCK(); 1302 shmseg = shm_find_segment(rpr, uap->shmid, true); 1303 if (shmseg == NULL) { 1304 SYSVSHM_UNLOCK(); 1305 return (EINVAL); 1306 } 1307 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); 1308 if (error != 0) { 1309 SYSVSHM_UNLOCK(); 1310 return (error); 1311 } 1312 #ifdef MAC 1313 error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd); 1314 if (error != 0) { 1315 SYSVSHM_UNLOCK(); 1316 return (error); 1317 } 1318 #endif 1319 ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm); 1320 outbuf.shm_segsz = shmseg->u.shm_segsz; 1321 outbuf.shm_cpid = shmseg->u.shm_cpid; 1322 outbuf.shm_lpid = shmseg->u.shm_lpid; 1323 outbuf.shm_nattch = shmseg->u.shm_nattch; 1324 outbuf.shm_atime = shmseg->u.shm_atime; 1325 outbuf.shm_dtime = shmseg->u.shm_dtime; 1326 outbuf.shm_ctime = shmseg->u.shm_ctime; 1327 outbuf.shm_handle = shmseg->object; 1328 SYSVSHM_UNLOCK(); 1329 return (copyout(&outbuf, uap->ubuf, sizeof(outbuf))); 1330 #else 1331 return (EINVAL); 1332 #endif 1333 } 1334 1335 /* XXX casting to (sy_call_t *) is bogus, as usual. */ 1336 static sy_call_t *shmcalls[] = { 1337 (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl, 1338 (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget, 1339 (sy_call_t *)freebsd7_shmctl 1340 }; 1341 1342 #ifndef _SYS_SYSPROTO_H_ 1343 /* XXX actually varargs. */ 1344 struct shmsys_args { 1345 int which; 1346 int a2; 1347 int a3; 1348 int a4; 1349 }; 1350 #endif 1351 int 1352 sys_shmsys(struct thread *td, struct shmsys_args *uap) 1353 { 1354 1355 AUDIT_ARG_SVIPC_WHICH(uap->which); 1356 if (uap->which < 0 || uap->which >= nitems(shmcalls)) 1357 return (EINVAL); 1358 return ((*shmcalls[uap->which])(td, &uap->a2)); 1359 } 1360 1361 #endif /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */ 1362 1363 #ifdef COMPAT_FREEBSD32 1364 1365 int 1366 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap) 1367 { 1368 1369 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1370 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1371 AUDIT_ARG_SVIPC_WHICH(uap->which); 1372 switch (uap->which) { 1373 case 0: { /* shmat */ 1374 struct shmat_args ap; 1375 1376 ap.shmid = uap->a2; 1377 ap.shmaddr = PTRIN(uap->a3); 1378 ap.shmflg = uap->a4; 1379 return (sysent[SYS_shmat].sy_call(td, &ap)); 1380 } 1381 case 2: { /* shmdt */ 1382 struct shmdt_args ap; 1383 1384 ap.shmaddr = PTRIN(uap->a2); 1385 return (sysent[SYS_shmdt].sy_call(td, &ap)); 1386 } 1387 case 3: { /* shmget */ 1388 struct shmget_args ap; 1389 1390 ap.key = uap->a2; 1391 ap.size = uap->a3; 1392 ap.shmflg = uap->a4; 1393 return (sysent[SYS_shmget].sy_call(td, &ap)); 1394 } 1395 case 4: { /* shmctl */ 1396 struct freebsd7_freebsd32_shmctl_args ap; 1397 1398 ap.shmid = uap->a2; 1399 ap.cmd = uap->a3; 1400 ap.buf = PTRIN(uap->a4); 1401 return (freebsd7_freebsd32_shmctl(td, &ap)); 1402 } 1403 case 1: /* oshmctl */ 1404 default: 1405 return (EINVAL); 1406 } 1407 #else 1408 return (nosys(td, NULL)); 1409 #endif 1410 } 1411 1412 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1413 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1414 int 1415 freebsd7_freebsd32_shmctl(struct thread *td, 1416 struct freebsd7_freebsd32_shmctl_args *uap) 1417 { 1418 int error; 1419 union { 1420 struct shmid_ds shmid_ds; 1421 struct shm_info shm_info; 1422 struct shminfo shminfo; 1423 } u; 1424 union { 1425 struct shmid_ds32_old shmid_ds32; 1426 struct shm_info32 shm_info32; 1427 struct shminfo32 shminfo32; 1428 } u32; 1429 size_t sz; 1430 1431 if (uap->cmd == IPC_SET) { 1432 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1433 sizeof(u32.shmid_ds32)))) 1434 goto done; 1435 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm, 1436 &u.shmid_ds.shm_perm); 1437 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1438 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1439 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1440 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1441 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1442 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1443 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1444 } 1445 1446 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1447 if (error) 1448 goto done; 1449 1450 /* Cases in which we need to copyout */ 1451 switch (uap->cmd) { 1452 case IPC_INFO: 1453 CP(u.shminfo, u32.shminfo32, shmmax); 1454 CP(u.shminfo, u32.shminfo32, shmmin); 1455 CP(u.shminfo, u32.shminfo32, shmmni); 1456 CP(u.shminfo, u32.shminfo32, shmseg); 1457 CP(u.shminfo, u32.shminfo32, shmall); 1458 error = copyout(&u32.shminfo32, uap->buf, 1459 sizeof(u32.shminfo32)); 1460 break; 1461 case SHM_INFO: 1462 CP(u.shm_info, u32.shm_info32, used_ids); 1463 CP(u.shm_info, u32.shm_info32, shm_rss); 1464 CP(u.shm_info, u32.shm_info32, shm_tot); 1465 CP(u.shm_info, u32.shm_info32, shm_swp); 1466 CP(u.shm_info, u32.shm_info32, swap_attempts); 1467 CP(u.shm_info, u32.shm_info32, swap_successes); 1468 error = copyout(&u32.shm_info32, uap->buf, 1469 sizeof(u32.shm_info32)); 1470 break; 1471 case SHM_STAT: 1472 case IPC_STAT: 1473 memset(&u32.shmid_ds32, 0, sizeof(u32.shmid_ds32)); 1474 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm, 1475 &u32.shmid_ds32.shm_perm); 1476 if (u.shmid_ds.shm_segsz > INT32_MAX) 1477 u32.shmid_ds32.shm_segsz = INT32_MAX; 1478 else 1479 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1480 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1481 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1482 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1483 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1484 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1485 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1486 u32.shmid_ds32.shm_internal = 0; 1487 error = copyout(&u32.shmid_ds32, uap->buf, 1488 sizeof(u32.shmid_ds32)); 1489 break; 1490 } 1491 1492 done: 1493 if (error) { 1494 /* Invalidate the return value */ 1495 td->td_retval[0] = -1; 1496 } 1497 return (error); 1498 } 1499 #endif 1500 1501 int 1502 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap) 1503 { 1504 int error; 1505 union { 1506 struct shmid_ds shmid_ds; 1507 struct shm_info shm_info; 1508 struct shminfo shminfo; 1509 } u; 1510 union { 1511 struct shmid_ds32 shmid_ds32; 1512 struct shm_info32 shm_info32; 1513 struct shminfo32 shminfo32; 1514 } u32; 1515 size_t sz; 1516 1517 if (uap->cmd == IPC_SET) { 1518 if ((error = copyin(uap->buf, &u32.shmid_ds32, 1519 sizeof(u32.shmid_ds32)))) 1520 goto done; 1521 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm, 1522 &u.shmid_ds.shm_perm); 1523 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); 1524 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); 1525 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); 1526 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); 1527 CP(u32.shmid_ds32, u.shmid_ds, shm_atime); 1528 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); 1529 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); 1530 } 1531 1532 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); 1533 if (error) 1534 goto done; 1535 1536 /* Cases in which we need to copyout */ 1537 switch (uap->cmd) { 1538 case IPC_INFO: 1539 CP(u.shminfo, u32.shminfo32, shmmax); 1540 CP(u.shminfo, u32.shminfo32, shmmin); 1541 CP(u.shminfo, u32.shminfo32, shmmni); 1542 CP(u.shminfo, u32.shminfo32, shmseg); 1543 CP(u.shminfo, u32.shminfo32, shmall); 1544 error = copyout(&u32.shminfo32, uap->buf, 1545 sizeof(u32.shminfo32)); 1546 break; 1547 case SHM_INFO: 1548 CP(u.shm_info, u32.shm_info32, used_ids); 1549 CP(u.shm_info, u32.shm_info32, shm_rss); 1550 CP(u.shm_info, u32.shm_info32, shm_tot); 1551 CP(u.shm_info, u32.shm_info32, shm_swp); 1552 CP(u.shm_info, u32.shm_info32, swap_attempts); 1553 CP(u.shm_info, u32.shm_info32, swap_successes); 1554 error = copyout(&u32.shm_info32, uap->buf, 1555 sizeof(u32.shm_info32)); 1556 break; 1557 case SHM_STAT: 1558 case IPC_STAT: 1559 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm, 1560 &u32.shmid_ds32.shm_perm); 1561 if (u.shmid_ds.shm_segsz > INT32_MAX) 1562 u32.shmid_ds32.shm_segsz = INT32_MAX; 1563 else 1564 CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); 1565 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); 1566 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); 1567 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); 1568 CP(u.shmid_ds, u32.shmid_ds32, shm_atime); 1569 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); 1570 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); 1571 error = copyout(&u32.shmid_ds32, uap->buf, 1572 sizeof(u32.shmid_ds32)); 1573 break; 1574 } 1575 1576 done: 1577 if (error) { 1578 /* Invalidate the return value */ 1579 td->td_retval[0] = -1; 1580 } 1581 return (error); 1582 } 1583 #endif 1584 1585 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ 1586 defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) 1587 1588 #ifndef CP 1589 #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0) 1590 #endif 1591 1592 #ifndef _SYS_SYSPROTO_H_ 1593 struct freebsd7_shmctl_args { 1594 int shmid; 1595 int cmd; 1596 struct shmid_ds_old *buf; 1597 }; 1598 #endif 1599 int 1600 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap) 1601 { 1602 int error; 1603 struct shmid_ds_old old; 1604 struct shmid_ds buf; 1605 size_t bufsz; 1606 1607 /* 1608 * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support 1609 * Linux binaries. If we see the call come through the FreeBSD ABI, 1610 * return an error back to the user since we do not to support this. 1611 */ 1612 if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || 1613 uap->cmd == SHM_STAT) 1614 return (EINVAL); 1615 1616 /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ 1617 if (uap->cmd == IPC_SET) { 1618 if ((error = copyin(uap->buf, &old, sizeof(old)))) 1619 goto done; 1620 ipcperm_old2new(&old.shm_perm, &buf.shm_perm); 1621 CP(old, buf, shm_segsz); 1622 CP(old, buf, shm_lpid); 1623 CP(old, buf, shm_cpid); 1624 CP(old, buf, shm_nattch); 1625 CP(old, buf, shm_atime); 1626 CP(old, buf, shm_dtime); 1627 CP(old, buf, shm_ctime); 1628 } 1629 1630 error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); 1631 if (error) 1632 goto done; 1633 1634 /* Cases in which we need to copyout */ 1635 switch (uap->cmd) { 1636 case IPC_STAT: 1637 memset(&old, 0, sizeof(old)); 1638 ipcperm_new2old(&buf.shm_perm, &old.shm_perm); 1639 if (buf.shm_segsz > INT_MAX) 1640 old.shm_segsz = INT_MAX; 1641 else 1642 CP(buf, old, shm_segsz); 1643 CP(buf, old, shm_lpid); 1644 CP(buf, old, shm_cpid); 1645 if (buf.shm_nattch > SHRT_MAX) 1646 old.shm_nattch = SHRT_MAX; 1647 else 1648 CP(buf, old, shm_nattch); 1649 CP(buf, old, shm_atime); 1650 CP(buf, old, shm_dtime); 1651 CP(buf, old, shm_ctime); 1652 old.shm_internal = NULL; 1653 error = copyout(&old, uap->buf, sizeof(old)); 1654 break; 1655 } 1656 1657 done: 1658 if (error) { 1659 /* Invalidate the return value */ 1660 td->td_retval[0] = -1; 1661 } 1662 return (error); 1663 } 1664 1665 #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || 1666 COMPAT_FREEBSD7 */ 1667 1668 static int 1669 sysvshm_modload(struct module *module, int cmd, void *arg) 1670 { 1671 int error = 0; 1672 1673 switch (cmd) { 1674 case MOD_LOAD: 1675 error = shminit(); 1676 if (error != 0) 1677 shmunload(); 1678 break; 1679 case MOD_UNLOAD: 1680 error = shmunload(); 1681 break; 1682 case MOD_SHUTDOWN: 1683 break; 1684 default: 1685 error = EINVAL; 1686 break; 1687 } 1688 return (error); 1689 } 1690 1691 static moduledata_t sysvshm_mod = { 1692 "sysvshm", 1693 &sysvshm_modload, 1694 NULL 1695 }; 1696 1697 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST); 1698 MODULE_VERSION(sysvshm, 1);
Cache object: 57f006e0929a0b7eb7c1c9a851af7009
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