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