sys/kern/sysv_shm.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-4-Clause AND BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 1994 Adam Glass and Charles Hannum.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by Adam Glass and Charles
  17  *      Hannum.
  18  * 4. The names of the authors may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
  22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  24  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * $NetBSD: sysv_shm.c,v 1.39 1997/10/07 10:02:03 drochner Exp $
  33  */
  34 /*-
  35  * Copyright (c) 2003-2005 McAfee, Inc.
  36  * Copyright (c) 2016-2017 Robert N. M. Watson
  37  * All rights reserved.
  38  *
  39  * This software was developed for the FreeBSD Project in part by McAfee
  40  * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR
  41  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research
  42  * program.
  43  *
  44  * Portions of this software were developed by BAE Systems, the University of
  45  * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL
  46  * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent
  47  * Computing (TC) research program.
  48  *
  49  * Redistribution and use in source and binary forms, with or without
  50  * modification, are permitted provided that the following conditions
  51  * are met:
  52  * 1. Redistributions of source code must retain the above copyright
  53  *    notice, this list of conditions and the following disclaimer.
  54  * 2. Redistributions in binary form must reproduce the above copyright
  55  *    notice, this list of conditions and the following disclaimer in the
  56  *    documentation and/or other materials provided with the distribution.
  57  *
  58  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  68  * SUCH DAMAGE.
  69  */
  70
  71 #include <sys/cdefs.h>
  72 __FBSDID("$FreeBSD$");
  73
  74 #include "opt_sysvipc.h"
  75
  76 #include <sys/param.h>
  77 #include <sys/systm.h>
  78 #include <sys/kernel.h>
  79 #include <sys/limits.h>
  80 #include <sys/lock.h>
  81 #include <sys/sysctl.h>
  82 #include <sys/shm.h>
  83 #include <sys/proc.h>
  84 #include <sys/malloc.h>
  85 #include <sys/mman.h>
  86 #include <sys/module.h>
  87 #include <sys/mutex.h>
  88 #include <sys/racct.h>
  89 #include <sys/resourcevar.h>
  90 #include <sys/rwlock.h>
  91 #include <sys/stat.h>
  92 #include <sys/syscall.h>
  93 #include <sys/syscallsubr.h>
  94 #include <sys/sysent.h>
  95 #include <sys/sysproto.h>
  96 #include <sys/jail.h>
  97
  98 #include <security/audit/audit.h>
  99 #include <security/mac/mac_framework.h>
 100
 101 #include <vm/vm.h>
 102 #include <vm/vm_param.h>
 103 #include <vm/pmap.h>
 104 #include <vm/vm_object.h>
 105 #include <vm/vm_map.h>
 106 #include <vm/vm_page.h>
 107 #include <vm/vm_pager.h>
 108
 109 FEATURE(sysv_shm, "System V shared memory segments support");
 110
 111 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
 112
 113 static int shmget_allocate_segment(struct thread *td,
 114     struct shmget_args *uap, int mode);
 115 static int shmget_existing(struct thread *td, struct shmget_args *uap,
 116     int mode, int segnum);
 117
 118 #define SHMSEG_FREE             0x0200
 119 #define SHMSEG_REMOVED          0x0400
 120 #define SHMSEG_ALLOCATED        0x0800
 121
 122 static int shm_last_free, shm_nused, shmalloced;
 123 vm_size_t shm_committed;
 124 static struct shmid_kernel *shmsegs;
 125 static unsigned shm_prison_slot;
 126
 127 struct shmmap_state {
 128         vm_offset_t va;
 129         int shmid;
 130 };
 131
 132 static void shm_deallocate_segment(struct shmid_kernel *);
 133 static int shm_find_segment_by_key(struct prison *, key_t);
 134 static struct shmid_kernel *shm_find_segment(struct prison *, int, bool);
 135 static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *);
 136 static void shmrealloc(void);
 137 static int shminit(void);
 138 static int sysvshm_modload(struct module *, int, void *);
 139 static int shmunload(void);
 140 static void shmexit_myhook(struct vmspace *vm);
 141 static void shmfork_myhook(struct proc *p1, struct proc *p2);
 142 static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS);
 143 static void shm_remove(struct shmid_kernel *, int);
 144 static struct prison *shm_find_prison(struct ucred *);
 145 static int shm_prison_cansee(struct prison *, struct shmid_kernel *);
 146 static int shm_prison_check(void *, void *);
 147 static int shm_prison_set(void *, void *);
 148 static int shm_prison_get(void *, void *);
 149 static int shm_prison_remove(void *, void *);
 150 static void shm_prison_cleanup(struct prison *);
 151
 152 /*
 153  * Tuneable values.
 154  */
 155 #ifndef SHMMAXPGS
 156 #define SHMMAXPGS       131072  /* Note: sysv shared memory is swap backed. */
 157 #endif
 158 #ifndef SHMMAX
 159 #define SHMMAX  (SHMMAXPGS*PAGE_SIZE)
 160 #endif
 161 #ifndef SHMMIN
 162 #define SHMMIN  1
 163 #endif
 164 #ifndef SHMMNI
 165 #define SHMMNI  192
 166 #endif
 167 #ifndef SHMSEG
 168 #define SHMSEG  128
 169 #endif
 170 #ifndef SHMALL
 171 #define SHMALL  (SHMMAXPGS)
 172 #endif
 173
 174 struct  shminfo shminfo = {
 175         .shmmax = SHMMAX,
 176         .shmmin = SHMMIN,
 177         .shmmni = SHMMNI,
 178         .shmseg = SHMSEG,
 179         .shmall = SHMALL
 180 };
 181
 182 static int shm_use_phys;
 183 static int shm_allow_removed = 1;
 184
 185 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RWTUN, &shminfo.shmmax, 0,
 186     "Maximum shared memory segment size");
 187 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RWTUN, &shminfo.shmmin, 0,
 188     "Minimum shared memory segment size");
 189 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0,
 190     "Number of shared memory identifiers");
 191 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0,
 192     "Number of segments per process");
 193 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RWTUN, &shminfo.shmall, 0,
 194     "Maximum number of pages available for shared memory");
 195 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RWTUN,
 196     &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core");
 197 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RWTUN,
 198     &shm_allow_removed, 0,
 199     "Enable/Disable attachment to attached segments marked for removal");
 200 SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD |
 201     CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "",
 202     "Array of struct shmid_kernel for each potential shared memory segment");
 203
 204 static struct sx sysvshmsx;
 205 #define SYSVSHM_LOCK()          sx_xlock(&sysvshmsx)
 206 #define SYSVSHM_UNLOCK()        sx_xunlock(&sysvshmsx)
 207 #define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED)
 208
 209 static int
 210 shm_find_segment_by_key(struct prison *pr, key_t key)
 211 {
 212         int i;
 213
 214         for (i = 0; i < shmalloced; i++)
 215                 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) &&
 216                     shmsegs[i].cred != NULL &&
 217                     shmsegs[i].cred->cr_prison == pr &&
 218                     shmsegs[i].u.shm_perm.key == key)
 219                         return (i);
 220         return (-1);
 221 }
 222
 223 /*
 224  * Finds segment either by shmid if is_shmid is true, or by segnum if
 225  * is_shmid is false.
 226  */
 227 static struct shmid_kernel *
 228 shm_find_segment(struct prison *rpr, int arg, bool is_shmid)
 229 {
 230         struct shmid_kernel *shmseg;
 231         int segnum;
 232
 233         segnum = is_shmid ? IPCID_TO_IX(arg) : arg;
 234         if (segnum < 0 || segnum >= shmalloced)
 235                 return (NULL);
 236         shmseg = &shmsegs[segnum];
 237         if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
 238             (!shm_allow_removed &&
 239             (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) ||
 240             (is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg)) ||
 241             shm_prison_cansee(rpr, shmseg) != 0)
 242                 return (NULL);
 243         return (shmseg);
 244 }
 245
 246 static void
 247 shm_deallocate_segment(struct shmid_kernel *shmseg)
 248 {
 249         vm_size_t size;
 250
 251         SYSVSHM_ASSERT_LOCKED();
 252
 253         vm_object_deallocate(shmseg->object);
 254         shmseg->object = NULL;
 255         size = round_page(shmseg->u.shm_segsz);
 256         shm_committed -= btoc(size);
 257         shm_nused--;
 258         shmseg->u.shm_perm.mode = SHMSEG_FREE;
 259 #ifdef MAC
 260         mac_sysvshm_cleanup(shmseg);
 261 #endif
 262         racct_sub_cred(shmseg->cred, RACCT_NSHM, 1);
 263         racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size);
 264         crfree(shmseg->cred);
 265         shmseg->cred = NULL;
 266 }
 267
 268 static int
 269 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s)
 270 {
 271         struct shmid_kernel *shmseg;
 272         int segnum, result;
 273         vm_size_t size;
 274
 275         SYSVSHM_ASSERT_LOCKED();
 276         segnum = IPCID_TO_IX(shmmap_s->shmid);
 277         KASSERT(segnum >= 0 && segnum < shmalloced,
 278             ("segnum %d shmalloced %d", segnum, shmalloced));
 279
 280         shmseg = &shmsegs[segnum];
 281         size = round_page(shmseg->u.shm_segsz);
 282         result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size);
 283         if (result != KERN_SUCCESS)
 284                 return (EINVAL);
 285         shmmap_s->shmid = -1;
 286         shmseg->u.shm_dtime = time_second;
 287         if (--shmseg->u.shm_nattch == 0 &&
 288             (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) {
 289                 shm_deallocate_segment(shmseg);
 290                 shm_last_free = segnum;
 291         }
 292         return (0);
 293 }
 294
 295 static void
 296 shm_remove(struct shmid_kernel *shmseg, int segnum)
 297 {
 298
 299         shmseg->u.shm_perm.key = IPC_PRIVATE;
 300         shmseg->u.shm_perm.mode |= SHMSEG_REMOVED;
 301         if (shmseg->u.shm_nattch == 0) {
 302                 shm_deallocate_segment(shmseg);
 303                 shm_last_free = segnum;
 304         }
 305 }
 306
 307 static struct prison *
 308 shm_find_prison(struct ucred *cred)
 309 {
 310         struct prison *pr, *rpr;
 311
 312         pr = cred->cr_prison;
 313         prison_lock(pr);
 314         rpr = osd_jail_get(pr, shm_prison_slot);
 315         prison_unlock(pr);
 316         return rpr;
 317 }
 318
 319 static int
 320 shm_prison_cansee(struct prison *rpr, struct shmid_kernel *shmseg)
 321 {
 322
 323         if (shmseg->cred == NULL ||
 324             !(rpr == shmseg->cred->cr_prison ||
 325               prison_ischild(rpr, shmseg->cred->cr_prison)))
 326                 return (EINVAL);
 327         return (0);
 328 }
 329
 330 static int
 331 kern_shmdt_locked(struct thread *td, const void *shmaddr)
 332 {
 333         struct proc *p = td->td_proc;
 334         struct shmmap_state *shmmap_s;
 335 #ifdef MAC
 336         int error;
 337 #endif
 338         int i;
 339
 340         SYSVSHM_ASSERT_LOCKED();
 341         if (shm_find_prison(td->td_ucred) == NULL)
 342                 return (ENOSYS);
 343         shmmap_s = p->p_vmspace->vm_shm;
 344         if (shmmap_s == NULL)
 345                 return (EINVAL);
 346         AUDIT_ARG_SVIPC_ID(shmmap_s->shmid);
 347         for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
 348                 if (shmmap_s->shmid != -1 &&
 349                     shmmap_s->va == (vm_offset_t)shmaddr) {
 350                         break;
 351                 }
 352         }
 353         if (i == shminfo.shmseg)
 354                 return (EINVAL);
 355 #ifdef MAC
 356         error = mac_sysvshm_check_shmdt(td->td_ucred,
 357             &shmsegs[IPCID_TO_IX(shmmap_s->shmid)]);
 358         if (error != 0)
 359                 return (error);
 360 #endif
 361         return (shm_delete_mapping(p->p_vmspace, shmmap_s));
 362 }
 363
 364 #ifndef _SYS_SYSPROTO_H_
 365 struct shmdt_args {
 366         const void *shmaddr;
 367 };
 368 #endif
 369 int
 370 sys_shmdt(struct thread *td, struct shmdt_args *uap)
 371 {
 372         int error;
 373
 374         SYSVSHM_LOCK();
 375         error = kern_shmdt_locked(td, uap->shmaddr);
 376         SYSVSHM_UNLOCK();
 377         return (error);
 378 }
 379
 380 static int
 381 kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr,
 382     int shmflg)
 383 {
 384         struct prison *rpr;
 385         struct proc *p = td->td_proc;
 386         struct shmid_kernel *shmseg;
 387         struct shmmap_state *shmmap_s;
 388         vm_offset_t attach_va;
 389         vm_prot_t prot;
 390         vm_size_t size;
 391         int cow, error, find_space, i, rv;
 392
 393         AUDIT_ARG_SVIPC_ID(shmid);
 394         AUDIT_ARG_VALUE(shmflg);
 395
 396         SYSVSHM_ASSERT_LOCKED();
 397         rpr = shm_find_prison(td->td_ucred);
 398         if (rpr == NULL)
 399                 return (ENOSYS);
 400         shmmap_s = p->p_vmspace->vm_shm;
 401         if (shmmap_s == NULL) {
 402                 shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state),
 403                     M_SHM, M_WAITOK);
 404                 for (i = 0; i < shminfo.shmseg; i++)
 405                         shmmap_s[i].shmid = -1;
 406                 KASSERT(p->p_vmspace->vm_shm == NULL, ("raced"));
 407                 p->p_vmspace->vm_shm = shmmap_s;
 408         }
 409         shmseg = shm_find_segment(rpr, shmid, true);
 410         if (shmseg == NULL)
 411                 return (EINVAL);
 412         error = ipcperm(td, &shmseg->u.shm_perm,
 413             (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
 414         if (error != 0)
 415                 return (error);
 416 #ifdef MAC
 417         error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg);
 418         if (error != 0)
 419                 return (error);
 420 #endif
 421         for (i = 0; i < shminfo.shmseg; i++) {
 422                 if (shmmap_s->shmid == -1)
 423                         break;
 424                 shmmap_s++;
 425         }
 426         if (i >= shminfo.shmseg)
 427                 return (EMFILE);
 428         size = round_page(shmseg->u.shm_segsz);
 429         prot = VM_PROT_READ;
 430         cow = MAP_INHERIT_SHARE | MAP_PREFAULT_PARTIAL;
 431         if ((shmflg & SHM_RDONLY) == 0)
 432                 prot |= VM_PROT_WRITE;
 433         if (shmaddr != NULL) {
 434                 if ((shmflg & SHM_RND) != 0)
 435                         attach_va = rounddown2((vm_offset_t)shmaddr, SHMLBA);
 436                 else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0)
 437                         attach_va = (vm_offset_t)shmaddr;
 438                 else
 439                         return (EINVAL);
 440                 if ((shmflg & SHM_REMAP) != 0)
 441                         cow |= MAP_REMAP;
 442                 find_space = VMFS_NO_SPACE;
 443         } else {
 444                 /*
 445                  * This is just a hint to vm_map_find() about where to
 446                  * put it.
 447                  */
 448                 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr +
 449                     lim_max(td, RLIMIT_DATA));
 450                 find_space = VMFS_OPTIMAL_SPACE;
 451         }
 452
 453         vm_object_reference(shmseg->object);
 454         rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object, 0, &attach_va,
 455             size, 0, find_space, prot, prot, cow);
 456         if (rv != KERN_SUCCESS) {
 457                 vm_object_deallocate(shmseg->object);
 458                 return (ENOMEM);
 459         }
 460
 461         shmmap_s->va = attach_va;
 462         shmmap_s->shmid = shmid;
 463         shmseg->u.shm_lpid = p->p_pid;
 464         shmseg->u.shm_atime = time_second;
 465         shmseg->u.shm_nattch++;
 466         td->td_retval[0] = attach_va;
 467         return (error);
 468 }
 469
 470 int
 471 kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg)
 472 {
 473         int error;
 474
 475         SYSVSHM_LOCK();
 476         error = kern_shmat_locked(td, shmid, shmaddr, shmflg);
 477         SYSVSHM_UNLOCK();
 478         return (error);
 479 }
 480
 481 #ifndef _SYS_SYSPROTO_H_
 482 struct shmat_args {
 483         int shmid;
 484         const void *shmaddr;
 485         int shmflg;
 486 };
 487 #endif
 488 int
 489 sys_shmat(struct thread *td, struct shmat_args *uap)
 490 {
 491
 492         return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg));
 493 }
 494
 495 static int
 496 kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf,
 497     size_t *bufsz)
 498 {
 499         struct prison *rpr;
 500         struct shmid_kernel *shmseg;
 501         struct shmid_ds *shmidp;
 502         struct shm_info shm_info;
 503         int error;
 504
 505         SYSVSHM_ASSERT_LOCKED();
 506
 507         rpr = shm_find_prison(td->td_ucred);
 508         if (rpr == NULL)
 509                 return (ENOSYS);
 510
 511         AUDIT_ARG_SVIPC_ID(shmid);
 512         AUDIT_ARG_SVIPC_CMD(cmd);
 513
 514         switch (cmd) {
 515         /*
 516          * It is possible that kern_shmctl is being called from the Linux ABI
 517          * layer, in which case, we will need to implement IPC_INFO.  It should
 518          * be noted that other shmctl calls will be funneled through here for
 519          * Linix binaries as well.
 520          *
 521          * NB: The Linux ABI layer will convert this data to structure(s) more
 522          * consistent with the Linux ABI.
 523          */
 524         case IPC_INFO:
 525                 memcpy(buf, &shminfo, sizeof(shminfo));
 526                 if (bufsz)
 527                         *bufsz = sizeof(shminfo);
 528                 td->td_retval[0] = shmalloced;
 529                 return (0);
 530         case SHM_INFO: {
 531                 shm_info.used_ids = shm_nused;
 532                 shm_info.shm_rss = 0;   /*XXX where to get from ? */
 533                 shm_info.shm_tot = 0;   /*XXX where to get from ? */
 534                 shm_info.shm_swp = 0;   /*XXX where to get from ? */
 535                 shm_info.swap_attempts = 0;     /*XXX where to get from ? */
 536                 shm_info.swap_successes = 0;    /*XXX where to get from ? */
 537                 memcpy(buf, &shm_info, sizeof(shm_info));
 538                 if (bufsz != NULL)
 539                         *bufsz = sizeof(shm_info);
 540                 td->td_retval[0] = shmalloced;
 541                 return (0);
 542         }
 543         }
 544         shmseg = shm_find_segment(rpr, shmid, cmd != SHM_STAT);
 545         if (shmseg == NULL)
 546                 return (EINVAL);
 547 #ifdef MAC
 548         error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd);
 549         if (error != 0)
 550                 return (error);
 551 #endif
 552         switch (cmd) {
 553         case SHM_STAT:
 554         case IPC_STAT:
 555                 shmidp = (struct shmid_ds *)buf;
 556                 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
 557                 if (error != 0)
 558                         return (error);
 559                 memcpy(shmidp, &shmseg->u, sizeof(struct shmid_ds));
 560                 if (td->td_ucred->cr_prison != shmseg->cred->cr_prison)
 561                         shmidp->shm_perm.key = IPC_PRIVATE;
 562                 if (bufsz != NULL)
 563                         *bufsz = sizeof(struct shmid_ds);
 564                 if (cmd == SHM_STAT) {
 565                         td->td_retval[0] = IXSEQ_TO_IPCID(shmid,
 566                             shmseg->u.shm_perm);
 567                 }
 568                 break;
 569         case IPC_SET:
 570                 shmidp = (struct shmid_ds *)buf;
 571                 AUDIT_ARG_SVIPC_PERM(&shmidp->shm_perm);
 572                 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
 573                 if (error != 0)
 574                         return (error);
 575                 shmseg->u.shm_perm.uid = shmidp->shm_perm.uid;
 576                 shmseg->u.shm_perm.gid = shmidp->shm_perm.gid;
 577                 shmseg->u.shm_perm.mode =
 578                     (shmseg->u.shm_perm.mode & ~ACCESSPERMS) |
 579                     (shmidp->shm_perm.mode & ACCESSPERMS);
 580                 shmseg->u.shm_ctime = time_second;
 581                 break;
 582         case IPC_RMID:
 583                 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
 584                 if (error != 0)
 585                         return (error);
 586                 shm_remove(shmseg, IPCID_TO_IX(shmid));
 587                 break;
 588 #if 0
 589         case SHM_LOCK:
 590         case SHM_UNLOCK:
 591 #endif
 592         default:
 593                 error = EINVAL;
 594                 break;
 595         }
 596         return (error);
 597 }
 598
 599 int
 600 kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz)
 601 {
 602         int error;
 603
 604         SYSVSHM_LOCK();
 605         error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz);
 606         SYSVSHM_UNLOCK();
 607         return (error);
 608 }
 609
 610
 611 #ifndef _SYS_SYSPROTO_H_
 612 struct shmctl_args {
 613         int shmid;
 614         int cmd;
 615         struct shmid_ds *buf;
 616 };
 617 #endif
 618 int
 619 sys_shmctl(struct thread *td, struct shmctl_args *uap)
 620 {
 621         int error;
 622         struct shmid_ds buf;
 623         size_t bufsz;
 624
 625         /*
 626          * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
 627          * Linux binaries.  If we see the call come through the FreeBSD ABI,
 628          * return an error back to the user since we do not to support this.
 629          */
 630         if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
 631             uap->cmd == SHM_STAT)
 632                 return (EINVAL);
 633
 634         /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
 635         if (uap->cmd == IPC_SET) {
 636                 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds))))
 637                         goto done;
 638         }
 639
 640         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
 641         if (error)
 642                 goto done;
 643
 644         /* Cases in which we need to copyout */
 645         switch (uap->cmd) {
 646         case IPC_STAT:
 647                 error = copyout(&buf, uap->buf, bufsz);
 648                 break;
 649         }
 650
 651 done:
 652         if (error) {
 653                 /* Invalidate the return value */
 654                 td->td_retval[0] = -1;
 655         }
 656         return (error);
 657 }
 658
 659
 660 static int
 661 shmget_existing(struct thread *td, struct shmget_args *uap, int mode,
 662     int segnum)
 663 {
 664         struct shmid_kernel *shmseg;
 665 #ifdef MAC
 666         int error;
 667 #endif
 668
 669         SYSVSHM_ASSERT_LOCKED();
 670         KASSERT(segnum >= 0 && segnum < shmalloced,
 671             ("segnum %d shmalloced %d", segnum, shmalloced));
 672         shmseg = &shmsegs[segnum];
 673         if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
 674                 return (EEXIST);
 675 #ifdef MAC
 676         error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg);
 677         if (error != 0)
 678                 return (error);
 679 #endif
 680         if (uap->size != 0 && uap->size > shmseg->u.shm_segsz)
 681                 return (EINVAL);
 682         td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
 683         return (0);
 684 }
 685
 686 static int
 687 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode)
 688 {
 689         struct ucred *cred = td->td_ucred;
 690         struct shmid_kernel *shmseg;
 691         vm_object_t shm_object;
 692         int i, segnum;
 693         size_t size;
 694
 695         SYSVSHM_ASSERT_LOCKED();
 696
 697         if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
 698                 return (EINVAL);
 699         if (shm_nused >= shminfo.shmmni) /* Any shmids left? */
 700                 return (ENOSPC);
 701         size = round_page(uap->size);
 702         if (shm_committed + btoc(size) > shminfo.shmall)
 703                 return (ENOMEM);
 704         if (shm_last_free < 0) {
 705                 shmrealloc();   /* Maybe expand the shmsegs[] array. */
 706                 for (i = 0; i < shmalloced; i++)
 707                         if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE)
 708                                 break;
 709                 if (i == shmalloced)
 710                         return (ENOSPC);
 711                 segnum = i;
 712         } else  {
 713                 segnum = shm_last_free;
 714                 shm_last_free = -1;
 715         }
 716         KASSERT(segnum >= 0 && segnum < shmalloced,
 717             ("segnum %d shmalloced %d", segnum, shmalloced));
 718         shmseg = &shmsegs[segnum];
 719 #ifdef RACCT
 720         if (racct_enable) {
 721                 PROC_LOCK(td->td_proc);
 722                 if (racct_add(td->td_proc, RACCT_NSHM, 1)) {
 723                         PROC_UNLOCK(td->td_proc);
 724                         return (ENOSPC);
 725                 }
 726                 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) {
 727                         racct_sub(td->td_proc, RACCT_NSHM, 1);
 728                         PROC_UNLOCK(td->td_proc);
 729                         return (ENOMEM);
 730                 }
 731                 PROC_UNLOCK(td->td_proc);
 732         }
 733 #endif
 734
 735         /*
 736          * We make sure that we have allocated a pager before we need
 737          * to.
 738          */
 739         shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP,
 740             0, size, VM_PROT_DEFAULT, 0, cred);
 741         if (shm_object == NULL) {
 742 #ifdef RACCT
 743                 if (racct_enable) {
 744                         PROC_LOCK(td->td_proc);
 745                         racct_sub(td->td_proc, RACCT_NSHM, 1);
 746                         racct_sub(td->td_proc, RACCT_SHMSIZE, size);
 747                         PROC_UNLOCK(td->td_proc);
 748                 }
 749 #endif
 750                 return (ENOMEM);
 751         }
 752         shm_object->pg_color = 0;
 753         VM_OBJECT_WLOCK(shm_object);
 754         vm_object_clear_flag(shm_object, OBJ_ONEMAPPING);
 755         vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT);
 756         VM_OBJECT_WUNLOCK(shm_object);
 757
 758         shmseg->object = shm_object;
 759         shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid;
 760         shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid;
 761         shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
 762         shmseg->u.shm_perm.key = uap->key;
 763         shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff;
 764         shmseg->cred = crhold(cred);
 765         shmseg->u.shm_segsz = uap->size;
 766         shmseg->u.shm_cpid = td->td_proc->p_pid;
 767         shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0;
 768         shmseg->u.shm_atime = shmseg->u.shm_dtime = 0;
 769 #ifdef MAC
 770         mac_sysvshm_create(cred, shmseg);
 771 #endif
 772         shmseg->u.shm_ctime = time_second;
 773         shm_committed += btoc(size);
 774         shm_nused++;
 775         td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
 776
 777         return (0);
 778 }
 779
 780 #ifndef _SYS_SYSPROTO_H_
 781 struct shmget_args {
 782         key_t key;
 783         size_t size;
 784         int shmflg;
 785 };
 786 #endif
 787 int
 788 sys_shmget(struct thread *td, struct shmget_args *uap)
 789 {
 790         int segnum, mode;
 791         int error;
 792
 793         if (shm_find_prison(td->td_ucred) == NULL)
 794                 return (ENOSYS);
 795         mode = uap->shmflg & ACCESSPERMS;
 796         SYSVSHM_LOCK();
 797         if (uap->key == IPC_PRIVATE) {
 798                 error = shmget_allocate_segment(td, uap, mode);
 799         } else {
 800                 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison,
 801                     uap->key);
 802                 if (segnum >= 0)
 803                         error = shmget_existing(td, uap, mode, segnum);
 804                 else if ((uap->shmflg & IPC_CREAT) == 0)
 805                         error = ENOENT;
 806                 else
 807                         error = shmget_allocate_segment(td, uap, mode);
 808         }
 809         SYSVSHM_UNLOCK();
 810         return (error);
 811 }
 812
 813 static void
 814 shmfork_myhook(struct proc *p1, struct proc *p2)
 815 {
 816         struct shmmap_state *shmmap_s;
 817         size_t size;
 818         int i;
 819
 820         SYSVSHM_LOCK();
 821         size = shminfo.shmseg * sizeof(struct shmmap_state);
 822         shmmap_s = malloc(size, M_SHM, M_WAITOK);
 823         bcopy(p1->p_vmspace->vm_shm, shmmap_s, size);
 824         p2->p_vmspace->vm_shm = shmmap_s;
 825         for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
 826                 if (shmmap_s->shmid != -1) {
 827                         KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 &&
 828                             IPCID_TO_IX(shmmap_s->shmid) < shmalloced,
 829                             ("segnum %d shmalloced %d",
 830                             IPCID_TO_IX(shmmap_s->shmid), shmalloced));
 831                         shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++;
 832                 }
 833         }
 834         SYSVSHM_UNLOCK();
 835 }
 836
 837 static void
 838 shmexit_myhook(struct vmspace *vm)
 839 {
 840         struct shmmap_state *base, *shm;
 841         int i;
 842
 843         base = vm->vm_shm;
 844         if (base != NULL) {
 845                 vm->vm_shm = NULL;
 846                 SYSVSHM_LOCK();
 847                 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) {
 848                         if (shm->shmid != -1)
 849                                 shm_delete_mapping(vm, shm);
 850                 }
 851                 SYSVSHM_UNLOCK();
 852                 free(base, M_SHM);
 853         }
 854 }
 855
 856 static void
 857 shmrealloc(void)
 858 {
 859         struct shmid_kernel *newsegs;
 860         int i;
 861
 862         SYSVSHM_ASSERT_LOCKED();
 863
 864         if (shmalloced >= shminfo.shmmni)
 865                 return;
 866
 867         newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM,
 868             M_WAITOK | M_ZERO);
 869         for (i = 0; i < shmalloced; i++)
 870                 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
 871         for (; i < shminfo.shmmni; i++) {
 872                 newsegs[i].u.shm_perm.mode = SHMSEG_FREE;
 873                 newsegs[i].u.shm_perm.seq = 0;
 874 #ifdef MAC
 875                 mac_sysvshm_init(&newsegs[i]);
 876 #endif
 877         }
 878         free(shmsegs, M_SHM);
 879         shmsegs = newsegs;
 880         shmalloced = shminfo.shmmni;
 881 }
 882
 883 static struct syscall_helper_data shm_syscalls[] = {
 884         SYSCALL_INIT_HELPER(shmat),
 885         SYSCALL_INIT_HELPER(shmctl),
 886         SYSCALL_INIT_HELPER(shmdt),
 887         SYSCALL_INIT_HELPER(shmget),
 888 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 889     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 890         SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl),
 891 #endif
 892 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
 893         SYSCALL_INIT_HELPER(shmsys),
 894 #endif
 895         SYSCALL_INIT_LAST
 896 };
 897
 898 #ifdef COMPAT_FREEBSD32
 899 #include <compat/freebsd32/freebsd32.h>
 900 #include <compat/freebsd32/freebsd32_ipc.h>
 901 #include <compat/freebsd32/freebsd32_proto.h>
 902 #include <compat/freebsd32/freebsd32_signal.h>
 903 #include <compat/freebsd32/freebsd32_syscall.h>
 904 #include <compat/freebsd32/freebsd32_util.h>
 905
 906 static struct syscall_helper_data shm32_syscalls[] = {
 907         SYSCALL32_INIT_HELPER_COMPAT(shmat),
 908         SYSCALL32_INIT_HELPER_COMPAT(shmdt),
 909         SYSCALL32_INIT_HELPER_COMPAT(shmget),
 910         SYSCALL32_INIT_HELPER(freebsd32_shmsys),
 911         SYSCALL32_INIT_HELPER(freebsd32_shmctl),
 912 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 913     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 914         SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl),
 915 #endif
 916         SYSCALL_INIT_LAST
 917 };
 918 #endif
 919
 920 static int
 921 shminit(void)
 922 {
 923         struct prison *pr;
 924         void **rsv;
 925         int i, error;
 926         osd_method_t methods[PR_MAXMETHOD] = {
 927             [PR_METHOD_CHECK] =         shm_prison_check,
 928             [PR_METHOD_SET] =           shm_prison_set,
 929             [PR_METHOD_GET] =           shm_prison_get,
 930             [PR_METHOD_REMOVE] =        shm_prison_remove,
 931         };
 932
 933 #ifndef BURN_BRIDGES
 934         if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0)
 935                 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n");
 936 #endif
 937         if (shminfo.shmmax == SHMMAX) {
 938                 /* Initialize shmmax dealing with possible overflow. */
 939                 for (i = PAGE_SIZE; i != 0; i--) {
 940                         shminfo.shmmax = shminfo.shmall * i;
 941                         if ((shminfo.shmmax / shminfo.shmall) == (u_long)i)
 942                                 break;
 943                 }
 944         }
 945         shmalloced = shminfo.shmmni;
 946         shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM,
 947             M_WAITOK|M_ZERO);
 948         for (i = 0; i < shmalloced; i++) {
 949                 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE;
 950                 shmsegs[i].u.shm_perm.seq = 0;
 951 #ifdef MAC
 952                 mac_sysvshm_init(&shmsegs[i]);
 953 #endif
 954         }
 955         shm_last_free = 0;
 956         shm_nused = 0;
 957         shm_committed = 0;
 958         sx_init(&sysvshmsx, "sysvshmsx");
 959         shmexit_hook = &shmexit_myhook;
 960         shmfork_hook = &shmfork_myhook;
 961
 962         /* Set current prisons according to their allow.sysvipc. */
 963         shm_prison_slot = osd_jail_register(NULL, methods);
 964         rsv = osd_reserve(shm_prison_slot);
 965         prison_lock(&prison0);
 966         (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0);
 967         prison_unlock(&prison0);
 968         rsv = NULL;
 969         sx_slock(&allprison_lock);
 970         TAILQ_FOREACH(pr, &allprison, pr_list) {
 971                 if (rsv == NULL)
 972                         rsv = osd_reserve(shm_prison_slot);
 973                 prison_lock(pr);
 974                 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) {
 975                         (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
 976                             &prison0);
 977                         rsv = NULL;
 978                 }
 979                 prison_unlock(pr);
 980         }
 981         if (rsv != NULL)
 982                 osd_free_reserved(rsv);
 983         sx_sunlock(&allprison_lock);
 984
 985         error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD);
 986         if (error != 0)
 987                 return (error);
 988 #ifdef COMPAT_FREEBSD32
 989         error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD);
 990         if (error != 0)
 991                 return (error);
 992 #endif
 993         return (0);
 994 }
 995
 996 static int
 997 shmunload(void)
 998 {
 999         int i;
1000
1001         if (shm_nused > 0)
1002                 return (EBUSY);
1003
1004 #ifdef COMPAT_FREEBSD32
1005         syscall32_helper_unregister(shm32_syscalls);
1006 #endif
1007         syscall_helper_unregister(shm_syscalls);
1008         if (shm_prison_slot != 0)
1009                 osd_jail_deregister(shm_prison_slot);
1010
1011         for (i = 0; i < shmalloced; i++) {
1012 #ifdef MAC
1013                 mac_sysvshm_destroy(&shmsegs[i]);
1014 #endif
1015                 /*
1016                  * Objects might be still mapped into the processes
1017                  * address spaces.  Actual free would happen on the
1018                  * last mapping destruction.
1019                  */
1020                 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE)
1021                         vm_object_deallocate(shmsegs[i].object);
1022         }
1023         free(shmsegs, M_SHM);
1024         shmexit_hook = NULL;
1025         shmfork_hook = NULL;
1026         sx_destroy(&sysvshmsx);
1027         return (0);
1028 }
1029
1030 static int
1031 sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
1032 {
1033         struct shmid_kernel tshmseg;
1034 #ifdef COMPAT_FREEBSD32
1035         struct shmid_kernel32 tshmseg32;
1036 #endif
1037         struct prison *pr, *rpr;
1038         void *outaddr;
1039         size_t outsize;
1040         int error, i;
1041
1042         SYSVSHM_LOCK();
1043         pr = req->td->td_ucred->cr_prison;
1044         rpr = shm_find_prison(req->td->td_ucred);
1045         error = 0;
1046         for (i = 0; i < shmalloced; i++) {
1047                 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
1048                     rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) {
1049                         bzero(&tshmseg, sizeof(tshmseg));
1050                         tshmseg.u.shm_perm.mode = SHMSEG_FREE;
1051                 } else {
1052                         tshmseg = shmsegs[i];
1053                         if (tshmseg.cred->cr_prison != pr)
1054                                 tshmseg.u.shm_perm.key = IPC_PRIVATE;
1055                 }
1056 #ifdef COMPAT_FREEBSD32
1057                 if (SV_CURPROC_FLAG(SV_ILP32)) {
1058                         bzero(&tshmseg32, sizeof(tshmseg32));
1059                         freebsd32_ipcperm_out(&tshmseg.u.shm_perm,
1060                             &tshmseg32.u.shm_perm);
1061                         CP(tshmseg, tshmseg32, u.shm_segsz);
1062                         CP(tshmseg, tshmseg32, u.shm_lpid);
1063                         CP(tshmseg, tshmseg32, u.shm_cpid);
1064                         CP(tshmseg, tshmseg32, u.shm_nattch);
1065                         CP(tshmseg, tshmseg32, u.shm_atime);
1066                         CP(tshmseg, tshmseg32, u.shm_dtime);
1067                         CP(tshmseg, tshmseg32, u.shm_ctime);
1068                         /* Don't copy object, label, or cred */
1069                         outaddr = &tshmseg32;
1070                         outsize = sizeof(tshmseg32);
1071                 } else
1072 #endif
1073                 {
1074                         tshmseg.object = NULL;
1075                         tshmseg.label = NULL;
1076                         tshmseg.cred = NULL;
1077                         outaddr = &tshmseg;
1078                         outsize = sizeof(tshmseg);
1079                 }
1080                 error = SYSCTL_OUT(req, outaddr, outsize);
1081                 if (error != 0)
1082                         break;
1083         }
1084         SYSVSHM_UNLOCK();
1085         return (error);
1086 }
1087
1088 static int
1089 shm_prison_check(void *obj, void *data)
1090 {
1091         struct prison *pr = obj;
1092         struct prison *prpr;
1093         struct vfsoptlist *opts = data;
1094         int error, jsys;
1095
1096         /*
1097          * sysvshm is a jailsys integer.
1098          * It must be "disable" if the parent jail is disabled.
1099          */
1100         error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys));
1101         if (error != ENOENT) {
1102                 if (error != 0)
1103                         return (error);
1104                 switch (jsys) {
1105                 case JAIL_SYS_DISABLE:
1106                         break;
1107                 case JAIL_SYS_NEW:
1108                 case JAIL_SYS_INHERIT:
1109                         prison_lock(pr->pr_parent);
1110                         prpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1111                         prison_unlock(pr->pr_parent);
1112                         if (prpr == NULL)
1113                                 return (EPERM);
1114                         break;
1115                 default:
1116                         return (EINVAL);
1117                 }
1118         }
1119
1120         return (0);
1121 }
1122
1123 static int
1124 shm_prison_set(void *obj, void *data)
1125 {
1126         struct prison *pr = obj;
1127         struct prison *tpr, *orpr, *nrpr, *trpr;
1128         struct vfsoptlist *opts = data;
1129         void *rsv;
1130         int jsys, descend;
1131
1132         /*
1133          * sysvshm controls which jail is the root of the associated segments
1134          * (this jail or same as the parent), or if the feature is available
1135          * at all.
1136          */
1137         if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT)
1138                 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
1139                     ? JAIL_SYS_INHERIT
1140                     : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
1141                     ? JAIL_SYS_DISABLE
1142                     : -1;
1143         if (jsys == JAIL_SYS_DISABLE) {
1144                 prison_lock(pr);
1145                 orpr = osd_jail_get(pr, shm_prison_slot);
1146                 if (orpr != NULL)
1147                         osd_jail_del(pr, shm_prison_slot);
1148                 prison_unlock(pr);
1149                 if (orpr != NULL) {
1150                         if (orpr == pr)
1151                                 shm_prison_cleanup(pr);
1152                         /* Disable all child jails as well. */
1153                         FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1154                                 prison_lock(tpr);
1155                                 trpr = osd_jail_get(tpr, shm_prison_slot);
1156                                 if (trpr != NULL) {
1157                                         osd_jail_del(tpr, shm_prison_slot);
1158                                         prison_unlock(tpr);
1159                                         if (trpr == tpr)
1160                                                 shm_prison_cleanup(tpr);
1161                                 } else {
1162                                         prison_unlock(tpr);
1163                                         descend = 0;
1164                                 }
1165                         }
1166                 }
1167         } else if (jsys != -1) {
1168                 if (jsys == JAIL_SYS_NEW)
1169                         nrpr = pr;
1170                 else {
1171                         prison_lock(pr->pr_parent);
1172                         nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1173                         prison_unlock(pr->pr_parent);
1174                 }
1175                 rsv = osd_reserve(shm_prison_slot);
1176                 prison_lock(pr);
1177                 orpr = osd_jail_get(pr, shm_prison_slot);
1178                 if (orpr != nrpr)
1179                         (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
1180                             nrpr);
1181                 else
1182                         osd_free_reserved(rsv);
1183                 prison_unlock(pr);
1184                 if (orpr != nrpr) {
1185                         if (orpr == pr)
1186                                 shm_prison_cleanup(pr);
1187                         if (orpr != NULL) {
1188                                 /* Change child jails matching the old root, */
1189                                 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1190                                         prison_lock(tpr);
1191                                         trpr = osd_jail_get(tpr,
1192                                             shm_prison_slot);
1193                                         if (trpr == orpr) {
1194                                                 (void)osd_jail_set(tpr,
1195                                                     shm_prison_slot, nrpr);
1196                                                 prison_unlock(tpr);
1197                                                 if (trpr == tpr)
1198                                                         shm_prison_cleanup(tpr);
1199                                         } else {
1200                                                 prison_unlock(tpr);
1201                                                 descend = 0;
1202                                         }
1203                                 }
1204                         }
1205                 }
1206         }
1207
1208         return (0);
1209 }
1210
1211 static int
1212 shm_prison_get(void *obj, void *data)
1213 {
1214         struct prison *pr = obj;
1215         struct prison *rpr;
1216         struct vfsoptlist *opts = data;
1217         int error, jsys;
1218
1219         /* Set sysvshm based on the jail's root prison. */
1220         prison_lock(pr);
1221         rpr = osd_jail_get(pr, shm_prison_slot);
1222         prison_unlock(pr);
1223         jsys = rpr == NULL ? JAIL_SYS_DISABLE
1224             : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
1225         error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys));
1226         if (error == ENOENT)
1227                 error = 0;
1228         return (error);
1229 }
1230
1231 static int
1232 shm_prison_remove(void *obj, void *data __unused)
1233 {
1234         struct prison *pr = obj;
1235         struct prison *rpr;
1236
1237         SYSVSHM_LOCK();
1238         prison_lock(pr);
1239         rpr = osd_jail_get(pr, shm_prison_slot);
1240         prison_unlock(pr);
1241         if (rpr == pr)
1242                 shm_prison_cleanup(pr);
1243         SYSVSHM_UNLOCK();
1244         return (0);
1245 }
1246
1247 static void
1248 shm_prison_cleanup(struct prison *pr)
1249 {
1250         struct shmid_kernel *shmseg;
1251         int i;
1252
1253         /* Remove any segments that belong to this jail. */
1254         for (i = 0; i < shmalloced; i++) {
1255                 shmseg = &shmsegs[i];
1256                 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) &&
1257                     shmseg->cred != NULL && shmseg->cred->cr_prison == pr) {
1258                         shm_remove(shmseg, i);
1259                 }
1260         }
1261 }
1262
1263 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory");
1264
1265 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
1266 struct oshmid_ds {
1267         struct  ipc_perm_old shm_perm;  /* operation perms */
1268         int     shm_segsz;              /* size of segment (bytes) */
1269         u_short shm_cpid;               /* pid, creator */
1270         u_short shm_lpid;               /* pid, last operation */
1271         short   shm_nattch;             /* no. of current attaches */
1272         time_t  shm_atime;              /* last attach time */
1273         time_t  shm_dtime;              /* last detach time */
1274         time_t  shm_ctime;              /* last change time */
1275         void    *shm_handle;            /* internal handle for shm segment */
1276 };
1277
1278 struct oshmctl_args {
1279         int shmid;
1280         int cmd;
1281         struct oshmid_ds *ubuf;
1282 };
1283
1284 static int
1285 oshmctl(struct thread *td, struct oshmctl_args *uap)
1286 {
1287 #ifdef COMPAT_43
1288         int error = 0;
1289         struct prison *rpr;
1290         struct shmid_kernel *shmseg;
1291         struct oshmid_ds outbuf;
1292
1293         rpr = shm_find_prison(td->td_ucred);
1294         if (rpr == NULL)
1295                 return (ENOSYS);
1296         if (uap->cmd != IPC_STAT) {
1297                 return (freebsd7_shmctl(td,
1298                     (struct freebsd7_shmctl_args *)uap));
1299         }
1300         SYSVSHM_LOCK();
1301         shmseg = shm_find_segment(rpr, uap->shmid, true);
1302         if (shmseg == NULL) {
1303                 SYSVSHM_UNLOCK();
1304                 return (EINVAL);
1305         }
1306         error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
1307         if (error != 0) {
1308                 SYSVSHM_UNLOCK();
1309                 return (error);
1310         }
1311 #ifdef MAC
1312         error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd);
1313         if (error != 0) {
1314                 SYSVSHM_UNLOCK();
1315                 return (error);
1316         }
1317 #endif
1318         ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm);
1319         outbuf.shm_segsz = shmseg->u.shm_segsz;
1320         outbuf.shm_cpid = shmseg->u.shm_cpid;
1321         outbuf.shm_lpid = shmseg->u.shm_lpid;
1322         outbuf.shm_nattch = shmseg->u.shm_nattch;
1323         outbuf.shm_atime = shmseg->u.shm_atime;
1324         outbuf.shm_dtime = shmseg->u.shm_dtime;
1325         outbuf.shm_ctime = shmseg->u.shm_ctime;
1326         outbuf.shm_handle = shmseg->object;
1327         SYSVSHM_UNLOCK();
1328         return (copyout(&outbuf, uap->ubuf, sizeof(outbuf)));
1329 #else
1330         return (EINVAL);
1331 #endif
1332 }
1333
1334 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1335 static sy_call_t *shmcalls[] = {
1336         (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl,
1337         (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget,
1338         (sy_call_t *)freebsd7_shmctl
1339 };
1340
1341 #ifndef _SYS_SYSPROTO_H_
1342 /* XXX actually varargs. */
1343 struct shmsys_args {
1344         int     which;
1345         int     a2;
1346         int     a3;
1347         int     a4;
1348 };
1349 #endif
1350 int
1351 sys_shmsys(struct thread *td, struct shmsys_args *uap)
1352 {
1353
1354         AUDIT_ARG_SVIPC_WHICH(uap->which);
1355         if (uap->which < 0 || uap->which >= nitems(shmcalls))
1356                 return (EINVAL);
1357         return ((*shmcalls[uap->which])(td, &uap->a2));
1358 }
1359
1360 #endif  /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */
1361
1362 #ifdef COMPAT_FREEBSD32
1363
1364 int
1365 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap)
1366 {
1367
1368 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1369     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1370         AUDIT_ARG_SVIPC_WHICH(uap->which);
1371         switch (uap->which) {
1372         case 0: {       /* shmat */
1373                 struct shmat_args ap;
1374
1375                 ap.shmid = uap->a2;
1376                 ap.shmaddr = PTRIN(uap->a3);
1377                 ap.shmflg = uap->a4;
1378                 return (sysent[SYS_shmat].sy_call(td, &ap));
1379         }
1380         case 2: {       /* shmdt */
1381                 struct shmdt_args ap;
1382
1383                 ap.shmaddr = PTRIN(uap->a2);
1384                 return (sysent[SYS_shmdt].sy_call(td, &ap));
1385         }
1386         case 3: {       /* shmget */
1387                 struct shmget_args ap;
1388
1389                 ap.key = uap->a2;
1390                 ap.size = uap->a3;
1391                 ap.shmflg = uap->a4;
1392                 return (sysent[SYS_shmget].sy_call(td, &ap));
1393         }
1394         case 4: {       /* shmctl */
1395                 struct freebsd7_freebsd32_shmctl_args ap;
1396
1397                 ap.shmid = uap->a2;
1398                 ap.cmd = uap->a3;
1399                 ap.buf = PTRIN(uap->a4);
1400                 return (freebsd7_freebsd32_shmctl(td, &ap));
1401         }
1402         case 1:         /* oshmctl */
1403         default:
1404                 return (EINVAL);
1405         }
1406 #else
1407         return (nosys(td, NULL));
1408 #endif
1409 }
1410
1411 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1412     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1413 int
1414 freebsd7_freebsd32_shmctl(struct thread *td,
1415     struct freebsd7_freebsd32_shmctl_args *uap)
1416 {
1417         int error;
1418         union {
1419                 struct shmid_ds shmid_ds;
1420                 struct shm_info shm_info;
1421                 struct shminfo shminfo;
1422         } u;
1423         union {
1424                 struct shmid_ds32_old shmid_ds32;
1425                 struct shm_info32 shm_info32;
1426                 struct shminfo32 shminfo32;
1427         } u32;
1428         size_t sz;
1429
1430         if (uap->cmd == IPC_SET) {
1431                 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1432                     sizeof(u32.shmid_ds32))))
1433                         goto done;
1434                 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm,
1435                     &u.shmid_ds.shm_perm);
1436                 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1437                 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1438                 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1439                 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1440                 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1441                 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1442                 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1443         }
1444
1445         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1446         if (error)
1447                 goto done;
1448
1449         /* Cases in which we need to copyout */
1450         switch (uap->cmd) {
1451         case IPC_INFO:
1452                 CP(u.shminfo, u32.shminfo32, shmmax);
1453                 CP(u.shminfo, u32.shminfo32, shmmin);
1454                 CP(u.shminfo, u32.shminfo32, shmmni);
1455                 CP(u.shminfo, u32.shminfo32, shmseg);
1456                 CP(u.shminfo, u32.shminfo32, shmall);
1457                 error = copyout(&u32.shminfo32, uap->buf,
1458                     sizeof(u32.shminfo32));
1459                 break;
1460         case SHM_INFO:
1461                 CP(u.shm_info, u32.shm_info32, used_ids);
1462                 CP(u.shm_info, u32.shm_info32, shm_rss);
1463                 CP(u.shm_info, u32.shm_info32, shm_tot);
1464                 CP(u.shm_info, u32.shm_info32, shm_swp);
1465                 CP(u.shm_info, u32.shm_info32, swap_attempts);
1466                 CP(u.shm_info, u32.shm_info32, swap_successes);
1467                 error = copyout(&u32.shm_info32, uap->buf,
1468                     sizeof(u32.shm_info32));
1469                 break;
1470         case SHM_STAT:
1471         case IPC_STAT:
1472                 memset(&u32.shmid_ds32, 0, sizeof(u32.shmid_ds32));
1473                 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm,
1474                     &u32.shmid_ds32.shm_perm);
1475                 if (u.shmid_ds.shm_segsz > INT32_MAX)
1476                         u32.shmid_ds32.shm_segsz = INT32_MAX;
1477                 else
1478                         CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1479                 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1480                 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1481                 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1482                 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1483                 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1484                 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1485                 u32.shmid_ds32.shm_internal = 0;
1486                 error = copyout(&u32.shmid_ds32, uap->buf,
1487                     sizeof(u32.shmid_ds32));
1488                 break;
1489         }
1490
1491 done:
1492         if (error) {
1493                 /* Invalidate the return value */
1494                 td->td_retval[0] = -1;
1495         }
1496         return (error);
1497 }
1498 #endif
1499
1500 int
1501 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap)
1502 {
1503         int error;
1504         union {
1505                 struct shmid_ds shmid_ds;
1506                 struct shm_info shm_info;
1507                 struct shminfo shminfo;
1508         } u;
1509         union {
1510                 struct shmid_ds32 shmid_ds32;
1511                 struct shm_info32 shm_info32;
1512                 struct shminfo32 shminfo32;
1513         } u32;
1514         size_t sz;
1515
1516         if (uap->cmd == IPC_SET) {
1517                 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1518                     sizeof(u32.shmid_ds32))))
1519                         goto done;
1520                 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm,
1521                     &u.shmid_ds.shm_perm);
1522                 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1523                 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1524                 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1525                 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1526                 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1527                 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1528                 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1529         }
1530
1531         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1532         if (error)
1533                 goto done;
1534
1535         /* Cases in which we need to copyout */
1536         switch (uap->cmd) {
1537         case IPC_INFO:
1538                 CP(u.shminfo, u32.shminfo32, shmmax);
1539                 CP(u.shminfo, u32.shminfo32, shmmin);
1540                 CP(u.shminfo, u32.shminfo32, shmmni);
1541                 CP(u.shminfo, u32.shminfo32, shmseg);
1542                 CP(u.shminfo, u32.shminfo32, shmall);
1543                 error = copyout(&u32.shminfo32, uap->buf,
1544                     sizeof(u32.shminfo32));
1545                 break;
1546         case SHM_INFO:
1547                 CP(u.shm_info, u32.shm_info32, used_ids);
1548                 CP(u.shm_info, u32.shm_info32, shm_rss);
1549                 CP(u.shm_info, u32.shm_info32, shm_tot);
1550                 CP(u.shm_info, u32.shm_info32, shm_swp);
1551                 CP(u.shm_info, u32.shm_info32, swap_attempts);
1552                 CP(u.shm_info, u32.shm_info32, swap_successes);
1553                 error = copyout(&u32.shm_info32, uap->buf,
1554                     sizeof(u32.shm_info32));
1555                 break;
1556         case SHM_STAT:
1557         case IPC_STAT:
1558                 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm,
1559                     &u32.shmid_ds32.shm_perm);
1560                 if (u.shmid_ds.shm_segsz > INT32_MAX)
1561                         u32.shmid_ds32.shm_segsz = INT32_MAX;
1562                 else
1563                         CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1564                 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1565                 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1566                 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1567                 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1568                 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1569                 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1570                 error = copyout(&u32.shmid_ds32, uap->buf,
1571                     sizeof(u32.shmid_ds32));
1572                 break;
1573         }
1574
1575 done:
1576         if (error) {
1577                 /* Invalidate the return value */
1578                 td->td_retval[0] = -1;
1579         }
1580         return (error);
1581 }
1582 #endif
1583
1584 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1585     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1586
1587 #ifndef CP
1588 #define CP(src, dst, fld)       do { (dst).fld = (src).fld; } while (0)
1589 #endif
1590
1591 #ifndef _SYS_SYSPROTO_H_
1592 struct freebsd7_shmctl_args {
1593         int shmid;
1594         int cmd;
1595         struct shmid_ds_old *buf;
1596 };
1597 #endif
1598 int
1599 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap)
1600 {
1601         int error;
1602         struct shmid_ds_old old;
1603         struct shmid_ds buf;
1604         size_t bufsz;
1605
1606         /*
1607          * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
1608          * Linux binaries.  If we see the call come through the FreeBSD ABI,
1609          * return an error back to the user since we do not to support this.
1610          */
1611         if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
1612             uap->cmd == SHM_STAT)
1613                 return (EINVAL);
1614
1615         /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
1616         if (uap->cmd == IPC_SET) {
1617                 if ((error = copyin(uap->buf, &old, sizeof(old))))
1618                         goto done;
1619                 ipcperm_old2new(&old.shm_perm, &buf.shm_perm);
1620                 CP(old, buf, shm_segsz);
1621                 CP(old, buf, shm_lpid);
1622                 CP(old, buf, shm_cpid);
1623                 CP(old, buf, shm_nattch);
1624                 CP(old, buf, shm_atime);
1625                 CP(old, buf, shm_dtime);
1626                 CP(old, buf, shm_ctime);
1627         }
1628
1629         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
1630         if (error)
1631                 goto done;
1632
1633         /* Cases in which we need to copyout */
1634         switch (uap->cmd) {
1635         case IPC_STAT:
1636                 memset(&old, 0, sizeof(old));
1637                 ipcperm_new2old(&buf.shm_perm, &old.shm_perm);
1638                 if (buf.shm_segsz > INT_MAX)
1639                         old.shm_segsz = INT_MAX;
1640                 else
1641                         CP(buf, old, shm_segsz);
1642                 CP(buf, old, shm_lpid);
1643                 CP(buf, old, shm_cpid);
1644                 if (buf.shm_nattch > SHRT_MAX)
1645                         old.shm_nattch = SHRT_MAX;
1646                 else
1647                         CP(buf, old, shm_nattch);
1648                 CP(buf, old, shm_atime);
1649                 CP(buf, old, shm_dtime);
1650                 CP(buf, old, shm_ctime);
1651                 old.shm_internal = NULL;
1652                 error = copyout(&old, uap->buf, sizeof(old));
1653                 break;
1654         }
1655
1656 done:
1657         if (error) {
1658                 /* Invalidate the return value */
1659                 td->td_retval[0] = -1;
1660         }
1661         return (error);
1662 }
1663
1664 #endif  /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1665            COMPAT_FREEBSD7 */
1666
1667 static int
1668 sysvshm_modload(struct module *module, int cmd, void *arg)
1669 {
1670         int error = 0;
1671
1672         switch (cmd) {
1673         case MOD_LOAD:
1674                 error = shminit();
1675                 if (error != 0)
1676                         shmunload();
1677                 break;
1678         case MOD_UNLOAD:
1679                 error = shmunload();
1680                 break;
1681         case MOD_SHUTDOWN:
1682                 break;
1683         default:
1684                 error = EINVAL;
1685                 break;
1686         }
1687         return (error);
1688 }
1689
1690 static moduledata_t sysvshm_mod = {
1691         "sysvshm",
1692         &sysvshm_modload,
1693         NULL
1694 };
1695
1696 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
1697 MODULE_VERSION(sysvshm, 1);