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
 613 #ifndef _SYS_SYSPROTO_H_
 614 struct shmctl_args {
 615         int shmid;
 616         int cmd;
 617         struct shmid_ds *buf;
 618 };
 619 #endif
 620 int
 621 sys_shmctl(struct thread *td, struct shmctl_args *uap)
 622 {
 623         int error;
 624         struct shmid_ds buf;
 625         size_t bufsz;
 626
 627         /*
 628          * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
 629          * Linux binaries.  If we see the call come through the FreeBSD ABI,
 630          * return an error back to the user since we do not to support this.
 631          */
 632         if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
 633             uap->cmd == SHM_STAT)
 634                 return (EINVAL);
 635
 636         /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
 637         if (uap->cmd == IPC_SET) {
 638                 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds))))
 639                         goto done;
 640         }
 641
 642         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
 643         if (error)
 644                 goto done;
 645
 646         /* Cases in which we need to copyout */
 647         switch (uap->cmd) {
 648         case IPC_STAT:
 649                 error = copyout(&buf, uap->buf, bufsz);
 650                 break;
 651         }
 652
 653 done:
 654         if (error) {
 655                 /* Invalidate the return value */
 656                 td->td_retval[0] = -1;
 657         }
 658         return (error);
 659 }
 660
 661
 662 static int
 663 shmget_existing(struct thread *td, struct shmget_args *uap, int mode,
 664     int segnum)
 665 {
 666         struct shmid_kernel *shmseg;
 667 #ifdef MAC
 668         int error;
 669 #endif
 670
 671         SYSVSHM_ASSERT_LOCKED();
 672         KASSERT(segnum >= 0 && segnum < shmalloced,
 673             ("segnum %d shmalloced %d", segnum, shmalloced));
 674         shmseg = &shmsegs[segnum];
 675         if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
 676                 return (EEXIST);
 677 #ifdef MAC
 678         error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg);
 679         if (error != 0)
 680                 return (error);
 681 #endif
 682         if (uap->size != 0 && uap->size > shmseg->u.shm_segsz)
 683                 return (EINVAL);
 684         td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
 685         return (0);
 686 }
 687
 688 static int
 689 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode)
 690 {
 691         struct ucred *cred = td->td_ucred;
 692         struct shmid_kernel *shmseg;
 693         vm_object_t shm_object;
 694         int i, segnum;
 695         size_t size;
 696
 697         SYSVSHM_ASSERT_LOCKED();
 698
 699         if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
 700                 return (EINVAL);
 701         if (shm_nused >= shminfo.shmmni) /* Any shmids left? */
 702                 return (ENOSPC);
 703         size = round_page(uap->size);
 704         if (shm_committed + btoc(size) > shminfo.shmall)
 705                 return (ENOMEM);
 706         if (shm_last_free < 0) {
 707                 shmrealloc();   /* Maybe expand the shmsegs[] array. */
 708                 for (i = 0; i < shmalloced; i++)
 709                         if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE)
 710                                 break;
 711                 if (i == shmalloced)
 712                         return (ENOSPC);
 713                 segnum = i;
 714         } else  {
 715                 segnum = shm_last_free;
 716                 shm_last_free = -1;
 717         }
 718         KASSERT(segnum >= 0 && segnum < shmalloced,
 719             ("segnum %d shmalloced %d", segnum, shmalloced));
 720         shmseg = &shmsegs[segnum];
 721 #ifdef RACCT
 722         if (racct_enable) {
 723                 PROC_LOCK(td->td_proc);
 724                 if (racct_add(td->td_proc, RACCT_NSHM, 1)) {
 725                         PROC_UNLOCK(td->td_proc);
 726                         return (ENOSPC);
 727                 }
 728                 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) {
 729                         racct_sub(td->td_proc, RACCT_NSHM, 1);
 730                         PROC_UNLOCK(td->td_proc);
 731                         return (ENOMEM);
 732                 }
 733                 PROC_UNLOCK(td->td_proc);
 734         }
 735 #endif
 736
 737         /*
 738          * We make sure that we have allocated a pager before we need
 739          * to.
 740          */
 741         shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP,
 742             0, size, VM_PROT_DEFAULT, 0, cred);
 743         if (shm_object == NULL) {
 744 #ifdef RACCT
 745                 if (racct_enable) {
 746                         PROC_LOCK(td->td_proc);
 747                         racct_sub(td->td_proc, RACCT_NSHM, 1);
 748                         racct_sub(td->td_proc, RACCT_SHMSIZE, size);
 749                         PROC_UNLOCK(td->td_proc);
 750                 }
 751 #endif
 752                 return (ENOMEM);
 753         }
 754         shm_object->pg_color = 0;
 755         VM_OBJECT_WLOCK(shm_object);
 756         vm_object_clear_flag(shm_object, OBJ_ONEMAPPING);
 757         vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT);
 758         VM_OBJECT_WUNLOCK(shm_object);
 759
 760         shmseg->object = shm_object;
 761         shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid;
 762         shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid;
 763         shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
 764         shmseg->u.shm_perm.key = uap->key;
 765         shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff;
 766         shmseg->cred = crhold(cred);
 767         shmseg->u.shm_segsz = uap->size;
 768         shmseg->u.shm_cpid = td->td_proc->p_pid;
 769         shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0;
 770         shmseg->u.shm_atime = shmseg->u.shm_dtime = 0;
 771 #ifdef MAC
 772         mac_sysvshm_create(cred, shmseg);
 773 #endif
 774         shmseg->u.shm_ctime = time_second;
 775         shm_committed += btoc(size);
 776         shm_nused++;
 777         td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
 778
 779         return (0);
 780 }
 781
 782 #ifndef _SYS_SYSPROTO_H_
 783 struct shmget_args {
 784         key_t key;
 785         size_t size;
 786         int shmflg;
 787 };
 788 #endif
 789 int
 790 sys_shmget(struct thread *td, struct shmget_args *uap)
 791 {
 792         int segnum, mode;
 793         int error;
 794
 795         if (shm_find_prison(td->td_ucred) == NULL)
 796                 return (ENOSYS);
 797         mode = uap->shmflg & ACCESSPERMS;
 798         SYSVSHM_LOCK();
 799         if (uap->key == IPC_PRIVATE) {
 800                 error = shmget_allocate_segment(td, uap, mode);
 801         } else {
 802                 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison,
 803                     uap->key);
 804                 if (segnum >= 0)
 805                         error = shmget_existing(td, uap, mode, segnum);
 806                 else if ((uap->shmflg & IPC_CREAT) == 0)
 807                         error = ENOENT;
 808                 else
 809                         error = shmget_allocate_segment(td, uap, mode);
 810         }
 811         SYSVSHM_UNLOCK();
 812         return (error);
 813 }
 814
 815 #ifdef SYSVSHM
 816 void
 817 shmfork(struct proc *p1, struct proc *p2)
 818 #else
 819 static void
 820 shmfork_myhook(struct proc *p1, struct proc *p2)
 821 #endif
 822 {
 823         struct shmmap_state *shmmap_s;
 824         size_t size;
 825         int i;
 826
 827         SYSVSHM_LOCK();
 828         size = shminfo.shmseg * sizeof(struct shmmap_state);
 829         shmmap_s = malloc(size, M_SHM, M_WAITOK);
 830         bcopy(p1->p_vmspace->vm_shm, shmmap_s, size);
 831         p2->p_vmspace->vm_shm = shmmap_s;
 832         for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
 833                 if (shmmap_s->shmid != -1) {
 834                         KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 &&
 835                             IPCID_TO_IX(shmmap_s->shmid) < shmalloced,
 836                             ("segnum %d shmalloced %d",
 837                             IPCID_TO_IX(shmmap_s->shmid), shmalloced));
 838                         shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++;
 839                 }
 840         }
 841         SYSVSHM_UNLOCK();
 842 }
 843
 844 #ifdef SYSVSHM
 845 void
 846 shmexit(struct vmspace *vm)
 847 #else
 848 static void
 849 shmexit_myhook(struct vmspace *vm)
 850 #endif
 851 {
 852         struct shmmap_state *base, *shm;
 853         int i;
 854
 855         base = vm->vm_shm;
 856         if (base != NULL) {
 857                 vm->vm_shm = NULL;
 858                 SYSVSHM_LOCK();
 859                 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) {
 860                         if (shm->shmid != -1)
 861                                 shm_delete_mapping(vm, shm);
 862                 }
 863                 SYSVSHM_UNLOCK();
 864                 free(base, M_SHM);
 865         }
 866 }
 867
 868 static void
 869 shmrealloc(void)
 870 {
 871         struct shmid_kernel *newsegs;
 872         int i;
 873
 874         SYSVSHM_ASSERT_LOCKED();
 875
 876         if (shmalloced >= shminfo.shmmni)
 877                 return;
 878
 879         newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM,
 880             M_WAITOK | M_ZERO);
 881         for (i = 0; i < shmalloced; i++)
 882                 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
 883         for (; i < shminfo.shmmni; i++) {
 884                 newsegs[i].u.shm_perm.mode = SHMSEG_FREE;
 885                 newsegs[i].u.shm_perm.seq = 0;
 886 #ifdef MAC
 887                 mac_sysvshm_init(&newsegs[i]);
 888 #endif
 889         }
 890         free(shmsegs, M_SHM);
 891         shmsegs = newsegs;
 892         shmalloced = shminfo.shmmni;
 893 }
 894
 895 static struct syscall_helper_data shm_syscalls[] = {
 896         SYSCALL_INIT_HELPER(shmat),
 897         SYSCALL_INIT_HELPER(shmctl),
 898         SYSCALL_INIT_HELPER(shmdt),
 899         SYSCALL_INIT_HELPER(shmget),
 900 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 901     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 902         SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl),
 903 #endif
 904 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
 905         SYSCALL_INIT_HELPER(shmsys),
 906 #endif
 907         SYSCALL_INIT_LAST
 908 };
 909
 910 #ifdef COMPAT_FREEBSD32
 911 #include <compat/freebsd32/freebsd32.h>
 912 #include <compat/freebsd32/freebsd32_ipc.h>
 913 #include <compat/freebsd32/freebsd32_proto.h>
 914 #include <compat/freebsd32/freebsd32_signal.h>
 915 #include <compat/freebsd32/freebsd32_syscall.h>
 916 #include <compat/freebsd32/freebsd32_util.h>
 917
 918 static struct syscall_helper_data shm32_syscalls[] = {
 919         SYSCALL32_INIT_HELPER_COMPAT(shmat),
 920         SYSCALL32_INIT_HELPER_COMPAT(shmdt),
 921         SYSCALL32_INIT_HELPER_COMPAT(shmget),
 922         SYSCALL32_INIT_HELPER(freebsd32_shmsys),
 923         SYSCALL32_INIT_HELPER(freebsd32_shmctl),
 924 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 925     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 926         SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl),
 927 #endif
 928         SYSCALL_INIT_LAST
 929 };
 930 #endif
 931
 932 static int
 933 shminit(void)
 934 {
 935         struct prison *pr;
 936         void **rsv;
 937         int i, error;
 938         osd_method_t methods[PR_MAXMETHOD] = {
 939             [PR_METHOD_CHECK] =         shm_prison_check,
 940             [PR_METHOD_SET] =           shm_prison_set,
 941             [PR_METHOD_GET] =           shm_prison_get,
 942             [PR_METHOD_REMOVE] =        shm_prison_remove,
 943         };
 944
 945 #ifndef BURN_BRIDGES
 946         if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0)
 947                 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n");
 948 #endif
 949         if (shminfo.shmmax == SHMMAX) {
 950                 /* Initialize shmmax dealing with possible overflow. */
 951                 for (i = PAGE_SIZE; i != 0; i--) {
 952                         shminfo.shmmax = shminfo.shmall * i;
 953                         if ((shminfo.shmmax / shminfo.shmall) == (u_long)i)
 954                                 break;
 955                 }
 956         }
 957         shmalloced = shminfo.shmmni;
 958         shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM,
 959             M_WAITOK|M_ZERO);
 960         for (i = 0; i < shmalloced; i++) {
 961                 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE;
 962                 shmsegs[i].u.shm_perm.seq = 0;
 963 #ifdef MAC
 964                 mac_sysvshm_init(&shmsegs[i]);
 965 #endif
 966         }
 967         shm_last_free = 0;
 968         shm_nused = 0;
 969         shm_committed = 0;
 970         sx_init(&sysvshmsx, "sysvshmsx");
 971 #ifndef SYSVSHM
 972         shmexit_hook = &shmexit_myhook;
 973         shmfork_hook = &shmfork_myhook;
 974 #endif
 975
 976         /* Set current prisons according to their allow.sysvipc. */
 977         shm_prison_slot = osd_jail_register(NULL, methods);
 978         rsv = osd_reserve(shm_prison_slot);
 979         prison_lock(&prison0);
 980         (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0);
 981         prison_unlock(&prison0);
 982         rsv = NULL;
 983         sx_slock(&allprison_lock);
 984         TAILQ_FOREACH(pr, &allprison, pr_list) {
 985                 if (rsv == NULL)
 986                         rsv = osd_reserve(shm_prison_slot);
 987                 prison_lock(pr);
 988                 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) {
 989                         (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
 990                             &prison0);
 991                         rsv = NULL;
 992                 }
 993                 prison_unlock(pr);
 994         }
 995         if (rsv != NULL)
 996                 osd_free_reserved(rsv);
 997         sx_sunlock(&allprison_lock);
 998
 999         error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD);
1000         if (error != 0)
1001                 return (error);
1002 #ifdef COMPAT_FREEBSD32
1003         error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD);
1004         if (error != 0)
1005                 return (error);
1006 #endif
1007         return (0);
1008 }
1009
1010 static int
1011 shmunload(void)
1012 {
1013         int i;
1014
1015         if (shm_nused > 0)
1016                 return (EBUSY);
1017
1018 #ifdef COMPAT_FREEBSD32
1019         syscall32_helper_unregister(shm32_syscalls);
1020 #endif
1021         syscall_helper_unregister(shm_syscalls);
1022         if (shm_prison_slot != 0)
1023                 osd_jail_deregister(shm_prison_slot);
1024
1025         for (i = 0; i < shmalloced; i++) {
1026 #ifdef MAC
1027                 mac_sysvshm_destroy(&shmsegs[i]);
1028 #endif
1029                 /*
1030                  * Objects might be still mapped into the processes
1031                  * address spaces.  Actual free would happen on the
1032                  * last mapping destruction.
1033                  */
1034                 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE)
1035                         vm_object_deallocate(shmsegs[i].object);
1036         }
1037         free(shmsegs, M_SHM);
1038 #ifndef SYSVSHM
1039         shmexit_hook = NULL;
1040         shmfork_hook = NULL;
1041 #endif
1042         sx_destroy(&sysvshmsx);
1043         return (0);
1044 }
1045
1046 static int
1047 sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
1048 {
1049         struct shmid_kernel tshmseg;
1050 #ifdef COMPAT_FREEBSD32
1051         struct shmid_kernel32 tshmseg32;
1052 #endif
1053         struct prison *pr, *rpr;
1054         void *outaddr;
1055         size_t outsize;
1056         int error, i;
1057
1058         SYSVSHM_LOCK();
1059         pr = req->td->td_ucred->cr_prison;
1060         rpr = shm_find_prison(req->td->td_ucred);
1061         error = 0;
1062         for (i = 0; i < shmalloced; i++) {
1063                 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
1064                     rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) {
1065                         bzero(&tshmseg, sizeof(tshmseg));
1066                         tshmseg.u.shm_perm.mode = SHMSEG_FREE;
1067                 } else {
1068                         tshmseg = shmsegs[i];
1069                         if (tshmseg.cred->cr_prison != pr)
1070                                 tshmseg.u.shm_perm.key = IPC_PRIVATE;
1071                 }
1072 #ifdef COMPAT_FREEBSD32
1073                 if (SV_CURPROC_FLAG(SV_ILP32)) {
1074                         bzero(&tshmseg32, sizeof(tshmseg32));
1075                         freebsd32_ipcperm_out(&tshmseg.u.shm_perm,
1076                             &tshmseg32.u.shm_perm);
1077                         CP(tshmseg, tshmseg32, u.shm_segsz);
1078                         CP(tshmseg, tshmseg32, u.shm_lpid);
1079                         CP(tshmseg, tshmseg32, u.shm_cpid);
1080                         CP(tshmseg, tshmseg32, u.shm_nattch);
1081                         CP(tshmseg, tshmseg32, u.shm_atime);
1082                         CP(tshmseg, tshmseg32, u.shm_dtime);
1083                         CP(tshmseg, tshmseg32, u.shm_ctime);
1084                         /* Don't copy object, label, or cred */
1085                         outaddr = &tshmseg32;
1086                         outsize = sizeof(tshmseg32);
1087                 } else
1088 #endif
1089                 {
1090                         tshmseg.object = NULL;
1091                         tshmseg.label = NULL;
1092                         tshmseg.cred = NULL;
1093                         outaddr = &tshmseg;
1094                         outsize = sizeof(tshmseg);
1095                 }
1096                 error = SYSCTL_OUT(req, outaddr, outsize);
1097                 if (error != 0)
1098                         break;
1099         }
1100         SYSVSHM_UNLOCK();
1101         return (error);
1102 }
1103
1104 static int
1105 shm_prison_check(void *obj, void *data)
1106 {
1107         struct prison *pr = obj;
1108         struct prison *prpr;
1109         struct vfsoptlist *opts = data;
1110         int error, jsys;
1111
1112         /*
1113          * sysvshm is a jailsys integer.
1114          * It must be "disable" if the parent jail is disabled.
1115          */
1116         error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys));
1117         if (error != ENOENT) {
1118                 if (error != 0)
1119                         return (error);
1120                 switch (jsys) {
1121                 case JAIL_SYS_DISABLE:
1122                         break;
1123                 case JAIL_SYS_NEW:
1124                 case JAIL_SYS_INHERIT:
1125                         prison_lock(pr->pr_parent);
1126                         prpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1127                         prison_unlock(pr->pr_parent);
1128                         if (prpr == NULL)
1129                                 return (EPERM);
1130                         break;
1131                 default:
1132                         return (EINVAL);
1133                 }
1134         }
1135
1136         return (0);
1137 }
1138
1139 static int
1140 shm_prison_set(void *obj, void *data)
1141 {
1142         struct prison *pr = obj;
1143         struct prison *tpr, *orpr, *nrpr, *trpr;
1144         struct vfsoptlist *opts = data;
1145         void *rsv;
1146         int jsys, descend;
1147
1148         /*
1149          * sysvshm controls which jail is the root of the associated segments
1150          * (this jail or same as the parent), or if the feature is available
1151          * at all.
1152          */
1153         if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT)
1154                 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
1155                     ? JAIL_SYS_INHERIT
1156                     : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
1157                     ? JAIL_SYS_DISABLE
1158                     : -1;
1159         if (jsys == JAIL_SYS_DISABLE) {
1160                 prison_lock(pr);
1161                 orpr = osd_jail_get(pr, shm_prison_slot);
1162                 if (orpr != NULL)
1163                         osd_jail_del(pr, shm_prison_slot);
1164                 prison_unlock(pr);
1165                 if (orpr != NULL) {
1166                         if (orpr == pr)
1167                                 shm_prison_cleanup(pr);
1168                         /* Disable all child jails as well. */
1169                         FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1170                                 prison_lock(tpr);
1171                                 trpr = osd_jail_get(tpr, shm_prison_slot);
1172                                 if (trpr != NULL) {
1173                                         osd_jail_del(tpr, shm_prison_slot);
1174                                         prison_unlock(tpr);
1175                                         if (trpr == tpr)
1176                                                 shm_prison_cleanup(tpr);
1177                                 } else {
1178                                         prison_unlock(tpr);
1179                                         descend = 0;
1180                                 }
1181                         }
1182                 }
1183         } else if (jsys != -1) {
1184                 if (jsys == JAIL_SYS_NEW)
1185                         nrpr = pr;
1186                 else {
1187                         prison_lock(pr->pr_parent);
1188                         nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1189                         prison_unlock(pr->pr_parent);
1190                 }
1191                 rsv = osd_reserve(shm_prison_slot);
1192                 prison_lock(pr);
1193                 orpr = osd_jail_get(pr, shm_prison_slot);
1194                 if (orpr != nrpr)
1195                         (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
1196                             nrpr);
1197                 else
1198                         osd_free_reserved(rsv);
1199                 prison_unlock(pr);
1200                 if (orpr != nrpr) {
1201                         if (orpr == pr)
1202                                 shm_prison_cleanup(pr);
1203                         if (orpr != NULL) {
1204                                 /* Change child jails matching the old root, */
1205                                 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1206                                         prison_lock(tpr);
1207                                         trpr = osd_jail_get(tpr,
1208                                             shm_prison_slot);
1209                                         if (trpr == orpr) {
1210                                                 (void)osd_jail_set(tpr,
1211                                                     shm_prison_slot, nrpr);
1212                                                 prison_unlock(tpr);
1213                                                 if (trpr == tpr)
1214                                                         shm_prison_cleanup(tpr);
1215                                         } else {
1216                                                 prison_unlock(tpr);
1217                                                 descend = 0;
1218                                         }
1219                                 }
1220                         }
1221                 }
1222         }
1223
1224         return (0);
1225 }
1226
1227 static int
1228 shm_prison_get(void *obj, void *data)
1229 {
1230         struct prison *pr = obj;
1231         struct prison *rpr;
1232         struct vfsoptlist *opts = data;
1233         int error, jsys;
1234
1235         /* Set sysvshm based on the jail's root prison. */
1236         prison_lock(pr);
1237         rpr = osd_jail_get(pr, shm_prison_slot);
1238         prison_unlock(pr);
1239         jsys = rpr == NULL ? JAIL_SYS_DISABLE
1240             : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
1241         error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys));
1242         if (error == ENOENT)
1243                 error = 0;
1244         return (error);
1245 }
1246
1247 static int
1248 shm_prison_remove(void *obj, void *data __unused)
1249 {
1250         struct prison *pr = obj;
1251         struct prison *rpr;
1252
1253         SYSVSHM_LOCK();
1254         prison_lock(pr);
1255         rpr = osd_jail_get(pr, shm_prison_slot);
1256         prison_unlock(pr);
1257         if (rpr == pr)
1258                 shm_prison_cleanup(pr);
1259         SYSVSHM_UNLOCK();
1260         return (0);
1261 }
1262
1263 static void
1264 shm_prison_cleanup(struct prison *pr)
1265 {
1266         struct shmid_kernel *shmseg;
1267         int i;
1268
1269         /* Remove any segments that belong to this jail. */
1270         for (i = 0; i < shmalloced; i++) {
1271                 shmseg = &shmsegs[i];
1272                 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) &&
1273                     shmseg->cred != NULL && shmseg->cred->cr_prison == pr) {
1274                         shm_remove(shmseg, i);
1275                 }
1276         }
1277 }
1278
1279 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory");
1280
1281 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
1282 struct oshmid_ds {
1283         struct  ipc_perm_old shm_perm;  /* operation perms */
1284         int     shm_segsz;              /* size of segment (bytes) */
1285         u_short shm_cpid;               /* pid, creator */
1286         u_short shm_lpid;               /* pid, last operation */
1287         short   shm_nattch;             /* no. of current attaches */
1288         time_t  shm_atime;              /* last attach time */
1289         time_t  shm_dtime;              /* last detach time */
1290         time_t  shm_ctime;              /* last change time */
1291         void    *shm_handle;            /* internal handle for shm segment */
1292 };
1293
1294 struct oshmctl_args {
1295         int shmid;
1296         int cmd;
1297         struct oshmid_ds *ubuf;
1298 };
1299
1300 static int
1301 oshmctl(struct thread *td, struct oshmctl_args *uap)
1302 {
1303 #ifdef COMPAT_43
1304         int error = 0;
1305         struct prison *rpr;
1306         struct shmid_kernel *shmseg;
1307         struct oshmid_ds outbuf;
1308
1309         rpr = shm_find_prison(td->td_ucred);
1310         if (rpr == NULL)
1311                 return (ENOSYS);
1312         if (uap->cmd != IPC_STAT) {
1313                 return (freebsd7_shmctl(td,
1314                     (struct freebsd7_shmctl_args *)uap));
1315         }
1316         SYSVSHM_LOCK();
1317         shmseg = shm_find_segment(rpr, uap->shmid, true);
1318         if (shmseg == NULL) {
1319                 SYSVSHM_UNLOCK();
1320                 return (EINVAL);
1321         }
1322         error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
1323         if (error != 0) {
1324                 SYSVSHM_UNLOCK();
1325                 return (error);
1326         }
1327 #ifdef MAC
1328         error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd);
1329         if (error != 0) {
1330                 SYSVSHM_UNLOCK();
1331                 return (error);
1332         }
1333 #endif
1334         ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm);
1335         outbuf.shm_segsz = shmseg->u.shm_segsz;
1336         outbuf.shm_cpid = shmseg->u.shm_cpid;
1337         outbuf.shm_lpid = shmseg->u.shm_lpid;
1338         outbuf.shm_nattch = shmseg->u.shm_nattch;
1339         outbuf.shm_atime = shmseg->u.shm_atime;
1340         outbuf.shm_dtime = shmseg->u.shm_dtime;
1341         outbuf.shm_ctime = shmseg->u.shm_ctime;
1342         outbuf.shm_handle = shmseg->object;
1343         SYSVSHM_UNLOCK();
1344         return (copyout(&outbuf, uap->ubuf, sizeof(outbuf)));
1345 #else
1346         return (EINVAL);
1347 #endif
1348 }
1349
1350 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1351 static sy_call_t *shmcalls[] = {
1352         (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl,
1353         (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget,
1354         (sy_call_t *)freebsd7_shmctl
1355 };
1356
1357 #ifndef _SYS_SYSPROTO_H_
1358 /* XXX actually varargs. */
1359 struct shmsys_args {
1360         int     which;
1361         int     a2;
1362         int     a3;
1363         int     a4;
1364 };
1365 #endif
1366 int
1367 sys_shmsys(struct thread *td, struct shmsys_args *uap)
1368 {
1369
1370         AUDIT_ARG_SVIPC_WHICH(uap->which);
1371         if (uap->which < 0 || uap->which >= nitems(shmcalls))
1372                 return (EINVAL);
1373         return ((*shmcalls[uap->which])(td, &uap->a2));
1374 }
1375
1376 #endif  /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */
1377
1378 #ifdef COMPAT_FREEBSD32
1379
1380 int
1381 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap)
1382 {
1383
1384 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1385     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1386         AUDIT_ARG_SVIPC_WHICH(uap->which);
1387         switch (uap->which) {
1388         case 0: {       /* shmat */
1389                 struct shmat_args ap;
1390
1391                 ap.shmid = uap->a2;
1392                 ap.shmaddr = PTRIN(uap->a3);
1393                 ap.shmflg = uap->a4;
1394                 return (sysent[SYS_shmat].sy_call(td, &ap));
1395         }
1396         case 2: {       /* shmdt */
1397                 struct shmdt_args ap;
1398
1399                 ap.shmaddr = PTRIN(uap->a2);
1400                 return (sysent[SYS_shmdt].sy_call(td, &ap));
1401         }
1402         case 3: {       /* shmget */
1403                 struct shmget_args ap;
1404
1405                 ap.key = uap->a2;
1406                 ap.size = uap->a3;
1407                 ap.shmflg = uap->a4;
1408                 return (sysent[SYS_shmget].sy_call(td, &ap));
1409         }
1410         case 4: {       /* shmctl */
1411                 struct freebsd7_freebsd32_shmctl_args ap;
1412
1413                 ap.shmid = uap->a2;
1414                 ap.cmd = uap->a3;
1415                 ap.buf = PTRIN(uap->a4);
1416                 return (freebsd7_freebsd32_shmctl(td, &ap));
1417         }
1418         case 1:         /* oshmctl */
1419         default:
1420                 return (EINVAL);
1421         }
1422 #else
1423         return (nosys(td, NULL));
1424 #endif
1425 }
1426
1427 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1428     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1429 int
1430 freebsd7_freebsd32_shmctl(struct thread *td,
1431     struct freebsd7_freebsd32_shmctl_args *uap)
1432 {
1433         int error;
1434         union {
1435                 struct shmid_ds shmid_ds;
1436                 struct shm_info shm_info;
1437                 struct shminfo shminfo;
1438         } u;
1439         union {
1440                 struct shmid_ds32_old shmid_ds32;
1441                 struct shm_info32 shm_info32;
1442                 struct shminfo32 shminfo32;
1443         } u32;
1444         size_t sz;
1445
1446         if (uap->cmd == IPC_SET) {
1447                 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1448                     sizeof(u32.shmid_ds32))))
1449                         goto done;
1450                 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm,
1451                     &u.shmid_ds.shm_perm);
1452                 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1453                 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1454                 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1455                 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1456                 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1457                 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1458                 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1459         }
1460
1461         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1462         if (error)
1463                 goto done;
1464
1465         /* Cases in which we need to copyout */
1466         switch (uap->cmd) {
1467         case IPC_INFO:
1468                 CP(u.shminfo, u32.shminfo32, shmmax);
1469                 CP(u.shminfo, u32.shminfo32, shmmin);
1470                 CP(u.shminfo, u32.shminfo32, shmmni);
1471                 CP(u.shminfo, u32.shminfo32, shmseg);
1472                 CP(u.shminfo, u32.shminfo32, shmall);
1473                 error = copyout(&u32.shminfo32, uap->buf,
1474                     sizeof(u32.shminfo32));
1475                 break;
1476         case SHM_INFO:
1477                 CP(u.shm_info, u32.shm_info32, used_ids);
1478                 CP(u.shm_info, u32.shm_info32, shm_rss);
1479                 CP(u.shm_info, u32.shm_info32, shm_tot);
1480                 CP(u.shm_info, u32.shm_info32, shm_swp);
1481                 CP(u.shm_info, u32.shm_info32, swap_attempts);
1482                 CP(u.shm_info, u32.shm_info32, swap_successes);
1483                 error = copyout(&u32.shm_info32, uap->buf,
1484                     sizeof(u32.shm_info32));
1485                 break;
1486         case SHM_STAT:
1487         case IPC_STAT:
1488                 memset(&u32.shmid_ds32, 0, sizeof(u32.shmid_ds32));
1489                 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm,
1490                     &u32.shmid_ds32.shm_perm);
1491                 if (u.shmid_ds.shm_segsz > INT32_MAX)
1492                         u32.shmid_ds32.shm_segsz = INT32_MAX;
1493                 else
1494                         CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1495                 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1496                 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1497                 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1498                 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1499                 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1500                 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1501                 u32.shmid_ds32.shm_internal = 0;
1502                 error = copyout(&u32.shmid_ds32, uap->buf,
1503                     sizeof(u32.shmid_ds32));
1504                 break;
1505         }
1506
1507 done:
1508         if (error) {
1509                 /* Invalidate the return value */
1510                 td->td_retval[0] = -1;
1511         }
1512         return (error);
1513 }
1514 #endif
1515
1516 int
1517 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap)
1518 {
1519         int error;
1520         union {
1521                 struct shmid_ds shmid_ds;
1522                 struct shm_info shm_info;
1523                 struct shminfo shminfo;
1524         } u;
1525         union {
1526                 struct shmid_ds32 shmid_ds32;
1527                 struct shm_info32 shm_info32;
1528                 struct shminfo32 shminfo32;
1529         } u32;
1530         size_t sz;
1531
1532         if (uap->cmd == IPC_SET) {
1533                 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1534                     sizeof(u32.shmid_ds32))))
1535                         goto done;
1536                 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm,
1537                     &u.shmid_ds.shm_perm);
1538                 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1539                 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1540                 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1541                 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1542                 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1543                 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1544                 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1545         }
1546
1547         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1548         if (error)
1549                 goto done;
1550
1551         /* Cases in which we need to copyout */
1552         switch (uap->cmd) {
1553         case IPC_INFO:
1554                 CP(u.shminfo, u32.shminfo32, shmmax);
1555                 CP(u.shminfo, u32.shminfo32, shmmin);
1556                 CP(u.shminfo, u32.shminfo32, shmmni);
1557                 CP(u.shminfo, u32.shminfo32, shmseg);
1558                 CP(u.shminfo, u32.shminfo32, shmall);
1559                 error = copyout(&u32.shminfo32, uap->buf,
1560                     sizeof(u32.shminfo32));
1561                 break;
1562         case SHM_INFO:
1563                 CP(u.shm_info, u32.shm_info32, used_ids);
1564                 CP(u.shm_info, u32.shm_info32, shm_rss);
1565                 CP(u.shm_info, u32.shm_info32, shm_tot);
1566                 CP(u.shm_info, u32.shm_info32, shm_swp);
1567                 CP(u.shm_info, u32.shm_info32, swap_attempts);
1568                 CP(u.shm_info, u32.shm_info32, swap_successes);
1569                 error = copyout(&u32.shm_info32, uap->buf,
1570                     sizeof(u32.shm_info32));
1571                 break;
1572         case SHM_STAT:
1573         case IPC_STAT:
1574                 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm,
1575                     &u32.shmid_ds32.shm_perm);
1576                 if (u.shmid_ds.shm_segsz > INT32_MAX)
1577                         u32.shmid_ds32.shm_segsz = INT32_MAX;
1578                 else
1579                         CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1580                 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1581                 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1582                 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1583                 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1584                 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1585                 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1586                 error = copyout(&u32.shmid_ds32, uap->buf,
1587                     sizeof(u32.shmid_ds32));
1588                 break;
1589         }
1590
1591 done:
1592         if (error) {
1593                 /* Invalidate the return value */
1594                 td->td_retval[0] = -1;
1595         }
1596         return (error);
1597 }
1598 #endif
1599
1600 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1601     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1602
1603 #ifndef CP
1604 #define CP(src, dst, fld)       do { (dst).fld = (src).fld; } while (0)
1605 #endif
1606
1607 #ifndef _SYS_SYSPROTO_H_
1608 struct freebsd7_shmctl_args {
1609         int shmid;
1610         int cmd;
1611         struct shmid_ds_old *buf;
1612 };
1613 #endif
1614 int
1615 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap)
1616 {
1617         int error;
1618         struct shmid_ds_old old;
1619         struct shmid_ds buf;
1620         size_t bufsz;
1621
1622         /*
1623          * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
1624          * Linux binaries.  If we see the call come through the FreeBSD ABI,
1625          * return an error back to the user since we do not to support this.
1626          */
1627         if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
1628             uap->cmd == SHM_STAT)
1629                 return (EINVAL);
1630
1631         /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
1632         if (uap->cmd == IPC_SET) {
1633                 if ((error = copyin(uap->buf, &old, sizeof(old))))
1634                         goto done;
1635                 ipcperm_old2new(&old.shm_perm, &buf.shm_perm);
1636                 CP(old, buf, shm_segsz);
1637                 CP(old, buf, shm_lpid);
1638                 CP(old, buf, shm_cpid);
1639                 CP(old, buf, shm_nattch);
1640                 CP(old, buf, shm_atime);
1641                 CP(old, buf, shm_dtime);
1642                 CP(old, buf, shm_ctime);
1643         }
1644
1645         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
1646         if (error)
1647                 goto done;
1648
1649         /* Cases in which we need to copyout */
1650         switch (uap->cmd) {
1651         case IPC_STAT:
1652                 memset(&old, 0, sizeof(old));
1653                 ipcperm_new2old(&buf.shm_perm, &old.shm_perm);
1654                 if (buf.shm_segsz > INT_MAX)
1655                         old.shm_segsz = INT_MAX;
1656                 else
1657                         CP(buf, old, shm_segsz);
1658                 CP(buf, old, shm_lpid);
1659                 CP(buf, old, shm_cpid);
1660                 if (buf.shm_nattch > SHRT_MAX)
1661                         old.shm_nattch = SHRT_MAX;
1662                 else
1663                         CP(buf, old, shm_nattch);
1664                 CP(buf, old, shm_atime);
1665                 CP(buf, old, shm_dtime);
1666                 CP(buf, old, shm_ctime);
1667                 old.shm_internal = NULL;
1668                 error = copyout(&old, uap->buf, sizeof(old));
1669                 break;
1670         }
1671
1672 done:
1673         if (error) {
1674                 /* Invalidate the return value */
1675                 td->td_retval[0] = -1;
1676         }
1677         return (error);
1678 }
1679
1680 #endif  /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1681            COMPAT_FREEBSD7 */
1682
1683 static int
1684 sysvshm_modload(struct module *module, int cmd, void *arg)
1685 {
1686         int error = 0;
1687
1688         switch (cmd) {
1689         case MOD_LOAD:
1690                 error = shminit();
1691                 if (error != 0)
1692                         shmunload();
1693                 break;
1694         case MOD_UNLOAD:
1695                 error = shmunload();
1696                 break;
1697         case MOD_SHUTDOWN:
1698                 break;
1699         default:
1700                 error = EINVAL;
1701                 break;
1702         }
1703         return (error);
1704 }
1705
1706 static moduledata_t sysvshm_mod = {
1707         "sysvshm",
1708         &sysvshm_modload,
1709         NULL
1710 };
1711
1712 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
1713 MODULE_VERSION(sysvshm, 1);