sys/kern/sysv_shm.c

   1 /*      $NetBSD: sysv_shm.c,v 1.23 1994/07/04 23:25:12 glass Exp $      */
   2 /*-
   3  * Copyright (c) 1994 Adam Glass and Charles Hannum.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by Adam Glass and Charles
  16  *      Hannum.
  17  * 4. The names of the authors may not be used to endorse or promote products
  18  *    derived from this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
  21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  23  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  24  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  25  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  29  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31 /*-
  32  * Copyright (c) 2003-2005 McAfee, Inc.
  33  * Copyright (c) 2016-2017 Robert N. M. Watson
  34  * All rights reserved.
  35  *
  36  * This software was developed for the FreeBSD Project in part by McAfee
  37  * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR
  38  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research
  39  * program.
  40  *
  41  * Portions of this software were developed by BAE Systems, the University of
  42  * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL
  43  * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent
  44  * Computing (TC) research program.
  45  *
  46  * Redistribution and use in source and binary forms, with or without
  47  * modification, are permitted provided that the following conditions
  48  * are met:
  49  * 1. Redistributions of source code must retain the above copyright
  50  *    notice, this list of conditions and the following disclaimer.
  51  * 2. Redistributions in binary form must reproduce the above copyright
  52  *    notice, this list of conditions and the following disclaimer in the
  53  *    documentation and/or other materials provided with the distribution.
  54  *
  55  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  65  * SUCH DAMAGE.
  66  */
  67
  68 #include <sys/cdefs.h>
  69 __FBSDID("$FreeBSD$");
  70
  71 #include "opt_compat.h"
  72 #include "opt_sysvipc.h"
  73
  74 #include <sys/param.h>
  75 #include <sys/systm.h>
  76 #include <sys/kernel.h>
  77 #include <sys/limits.h>
  78 #include <sys/lock.h>
  79 #include <sys/sysctl.h>
  80 #include <sys/shm.h>
  81 #include <sys/proc.h>
  82 #include <sys/malloc.h>
  83 #include <sys/mman.h>
  84 #include <sys/module.h>
  85 #include <sys/mutex.h>
  86 #include <sys/racct.h>
  87 #include <sys/resourcevar.h>
  88 #include <sys/rwlock.h>
  89 #include <sys/stat.h>
  90 #include <sys/syscall.h>
  91 #include <sys/syscallsubr.h>
  92 #include <sys/sysent.h>
  93 #include <sys/sysproto.h>
  94 #include <sys/jail.h>
  95
  96 #include <security/audit/audit.h>
  97 #include <security/mac/mac_framework.h>
  98
  99 #include <vm/vm.h>
 100 #include <vm/vm_param.h>
 101 #include <vm/pmap.h>
 102 #include <vm/vm_object.h>
 103 #include <vm/vm_map.h>
 104 #include <vm/vm_page.h>
 105 #include <vm/vm_pager.h>
 106
 107 FEATURE(sysv_shm, "System V shared memory segments support");
 108
 109 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
 110
 111 static int shmget_allocate_segment(struct thread *td,
 112     struct shmget_args *uap, int mode);
 113 static int shmget_existing(struct thread *td, struct shmget_args *uap,
 114     int mode, int segnum);
 115
 116 #define SHMSEG_FREE             0x0200
 117 #define SHMSEG_REMOVED          0x0400
 118 #define SHMSEG_ALLOCATED        0x0800
 119
 120 static int shm_last_free, shm_nused, shmalloced;
 121 vm_size_t shm_committed;
 122 static struct shmid_kernel *shmsegs;
 123 static unsigned shm_prison_slot;
 124
 125 struct shmmap_state {
 126         vm_offset_t va;
 127         int shmid;
 128 };
 129
 130 static void shm_deallocate_segment(struct shmid_kernel *);
 131 static int shm_find_segment_by_key(struct prison *, key_t);
 132 static struct shmid_kernel *shm_find_segment(struct prison *, int, bool);
 133 static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *);
 134 static void shmrealloc(void);
 135 static int shminit(void);
 136 static int sysvshm_modload(struct module *, int, void *);
 137 static int shmunload(void);
 138 static void shmexit_myhook(struct vmspace *vm);
 139 static void shmfork_myhook(struct proc *p1, struct proc *p2);
 140 static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS);
 141 static void shm_remove(struct shmid_kernel *, int);
 142 static struct prison *shm_find_prison(struct ucred *);
 143 static int shm_prison_cansee(struct prison *, struct shmid_kernel *);
 144 static int shm_prison_check(void *, void *);
 145 static int shm_prison_set(void *, void *);
 146 static int shm_prison_get(void *, void *);
 147 static int shm_prison_remove(void *, void *);
 148 static void shm_prison_cleanup(struct prison *);
 149
 150 /*
 151  * Tuneable values.
 152  */
 153 #ifndef SHMMAXPGS
 154 #define SHMMAXPGS       131072  /* Note: sysv shared memory is swap backed. */
 155 #endif
 156 #ifndef SHMMAX
 157 #define SHMMAX  (SHMMAXPGS*PAGE_SIZE)
 158 #endif
 159 #ifndef SHMMIN
 160 #define SHMMIN  1
 161 #endif
 162 #ifndef SHMMNI
 163 #define SHMMNI  192
 164 #endif
 165 #ifndef SHMSEG
 166 #define SHMSEG  128
 167 #endif
 168 #ifndef SHMALL
 169 #define SHMALL  (SHMMAXPGS)
 170 #endif
 171
 172 struct  shminfo shminfo = {
 173         .shmmax = SHMMAX,
 174         .shmmin = SHMMIN,
 175         .shmmni = SHMMNI,
 176         .shmseg = SHMSEG,
 177         .shmall = SHMALL
 178 };
 179
 180 static int shm_use_phys;
 181 static int shm_allow_removed = 1;
 182
 183 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RWTUN, &shminfo.shmmax, 0,
 184     "Maximum shared memory segment size");
 185 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RWTUN, &shminfo.shmmin, 0,
 186     "Minimum shared memory segment size");
 187 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0,
 188     "Number of shared memory identifiers");
 189 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0,
 190     "Number of segments per process");
 191 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RWTUN, &shminfo.shmall, 0,
 192     "Maximum number of pages available for shared memory");
 193 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RWTUN,
 194     &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core");
 195 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RWTUN,
 196     &shm_allow_removed, 0,
 197     "Enable/Disable attachment to attached segments marked for removal");
 198 SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD |
 199     CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "",
 200     "Current number of shared memory segments allocated");
 201
 202 static struct sx sysvshmsx;
 203 #define SYSVSHM_LOCK()          sx_xlock(&sysvshmsx)
 204 #define SYSVSHM_UNLOCK()        sx_xunlock(&sysvshmsx)
 205 #define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED)
 206
 207 static int
 208 shm_find_segment_by_key(struct prison *pr, key_t key)
 209 {
 210         int i;
 211
 212         for (i = 0; i < shmalloced; i++)
 213                 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) &&
 214                     shmsegs[i].cred != NULL &&
 215                     shmsegs[i].cred->cr_prison == pr &&
 216                     shmsegs[i].u.shm_perm.key == key)
 217                         return (i);
 218         return (-1);
 219 }
 220
 221 /*
 222  * Finds segment either by shmid if is_shmid is true, or by segnum if
 223  * is_shmid is false.
 224  */
 225 static struct shmid_kernel *
 226 shm_find_segment(struct prison *rpr, int arg, bool is_shmid)
 227 {
 228         struct shmid_kernel *shmseg;
 229         int segnum;
 230
 231         segnum = is_shmid ? IPCID_TO_IX(arg) : arg;
 232         if (segnum < 0 || segnum >= shmalloced)
 233                 return (NULL);
 234         shmseg = &shmsegs[segnum];
 235         if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
 236             (!shm_allow_removed &&
 237             (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) ||
 238             (is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg)) ||
 239             shm_prison_cansee(rpr, shmseg) != 0)
 240                 return (NULL);
 241         return (shmseg);
 242 }
 243
 244 static void
 245 shm_deallocate_segment(struct shmid_kernel *shmseg)
 246 {
 247         vm_size_t size;
 248
 249         SYSVSHM_ASSERT_LOCKED();
 250
 251         vm_object_deallocate(shmseg->object);
 252         shmseg->object = NULL;
 253         size = round_page(shmseg->u.shm_segsz);
 254         shm_committed -= btoc(size);
 255         shm_nused--;
 256         shmseg->u.shm_perm.mode = SHMSEG_FREE;
 257 #ifdef MAC
 258         mac_sysvshm_cleanup(shmseg);
 259 #endif
 260         racct_sub_cred(shmseg->cred, RACCT_NSHM, 1);
 261         racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size);
 262         crfree(shmseg->cred);
 263         shmseg->cred = NULL;
 264 }
 265
 266 static int
 267 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s)
 268 {
 269         struct shmid_kernel *shmseg;
 270         int segnum, result;
 271         vm_size_t size;
 272
 273         SYSVSHM_ASSERT_LOCKED();
 274         segnum = IPCID_TO_IX(shmmap_s->shmid);
 275         KASSERT(segnum >= 0 && segnum < shmalloced,
 276             ("segnum %d shmalloced %d", segnum, shmalloced));
 277
 278         shmseg = &shmsegs[segnum];
 279         size = round_page(shmseg->u.shm_segsz);
 280         result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size);
 281         if (result != KERN_SUCCESS)
 282                 return (EINVAL);
 283         shmmap_s->shmid = -1;
 284         shmseg->u.shm_dtime = time_second;
 285         if (--shmseg->u.shm_nattch == 0 &&
 286             (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) {
 287                 shm_deallocate_segment(shmseg);
 288                 shm_last_free = segnum;
 289         }
 290         return (0);
 291 }
 292
 293 static void
 294 shm_remove(struct shmid_kernel *shmseg, int segnum)
 295 {
 296
 297         shmseg->u.shm_perm.key = IPC_PRIVATE;
 298         shmseg->u.shm_perm.mode |= SHMSEG_REMOVED;
 299         if (shmseg->u.shm_nattch == 0) {
 300                 shm_deallocate_segment(shmseg);
 301                 shm_last_free = segnum;
 302         }
 303 }
 304
 305 static struct prison *
 306 shm_find_prison(struct ucred *cred)
 307 {
 308         struct prison *pr, *rpr;
 309
 310         pr = cred->cr_prison;
 311         prison_lock(pr);
 312         rpr = osd_jail_get(pr, shm_prison_slot);
 313         prison_unlock(pr);
 314         return rpr;
 315 }
 316
 317 static int
 318 shm_prison_cansee(struct prison *rpr, struct shmid_kernel *shmseg)
 319 {
 320
 321         if (shmseg->cred == NULL ||
 322             !(rpr == shmseg->cred->cr_prison ||
 323               prison_ischild(rpr, shmseg->cred->cr_prison)))
 324                 return (EINVAL);
 325         return (0);
 326 }
 327
 328 static int
 329 kern_shmdt_locked(struct thread *td, const void *shmaddr)
 330 {
 331         struct proc *p = td->td_proc;
 332         struct shmmap_state *shmmap_s;
 333 #if defined(AUDIT) || defined(MAC)
 334         struct shmid_kernel *shmsegptr;
 335 #endif
 336 #ifdef MAC
 337         int error;
 338 #endif
 339         int i;
 340
 341         SYSVSHM_ASSERT_LOCKED();
 342         if (shm_find_prison(td->td_ucred) == NULL)
 343                 return (ENOSYS);
 344         shmmap_s = p->p_vmspace->vm_shm;
 345         if (shmmap_s == NULL)
 346                 return (EINVAL);
 347         AUDIT_ARG_SVIPC_ID(shmmap_s->shmid);
 348         for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
 349                 if (shmmap_s->shmid != -1 &&
 350                     shmmap_s->va == (vm_offset_t)shmaddr) {
 351                         break;
 352                 }
 353         }
 354         if (i == shminfo.shmseg)
 355                 return (EINVAL);
 356 #if (defined(AUDIT) && defined(KDTRACE_HOOKS)) || defined(MAC)
 357         shmsegptr = &shmsegs[IPCID_TO_IX(shmmap_s->shmid)];
 358 #endif
 359 #ifdef MAC
 360         error = mac_sysvshm_check_shmdt(td->td_ucred, shmsegptr);
 361         if (error != 0)
 362                 return (error);
 363 #endif
 364         return (shm_delete_mapping(p->p_vmspace, shmmap_s));
 365 }
 366
 367 #ifndef _SYS_SYSPROTO_H_
 368 struct shmdt_args {
 369         const void *shmaddr;
 370 };
 371 #endif
 372 int
 373 sys_shmdt(struct thread *td, struct shmdt_args *uap)
 374 {
 375         int error;
 376
 377         SYSVSHM_LOCK();
 378         error = kern_shmdt_locked(td, uap->shmaddr);
 379         SYSVSHM_UNLOCK();
 380         return (error);
 381 }
 382
 383 static int
 384 kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr,
 385     int shmflg)
 386 {
 387         struct prison *rpr;
 388         struct proc *p = td->td_proc;
 389         struct shmid_kernel *shmseg;
 390         struct shmmap_state *shmmap_s;
 391         vm_offset_t attach_va;
 392         vm_prot_t prot;
 393         vm_size_t size;
 394         int error, i, rv;
 395
 396         AUDIT_ARG_SVIPC_ID(shmid);
 397         AUDIT_ARG_VALUE(shmflg);
 398
 399         SYSVSHM_ASSERT_LOCKED();
 400         rpr = shm_find_prison(td->td_ucred);
 401         if (rpr == NULL)
 402                 return (ENOSYS);
 403         shmmap_s = p->p_vmspace->vm_shm;
 404         if (shmmap_s == NULL) {
 405                 shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state),
 406                     M_SHM, M_WAITOK);
 407                 for (i = 0; i < shminfo.shmseg; i++)
 408                         shmmap_s[i].shmid = -1;
 409                 KASSERT(p->p_vmspace->vm_shm == NULL, ("raced"));
 410                 p->p_vmspace->vm_shm = shmmap_s;
 411         }
 412         shmseg = shm_find_segment(rpr, shmid, true);
 413         if (shmseg == NULL)
 414                 return (EINVAL);
 415         error = ipcperm(td, &shmseg->u.shm_perm,
 416             (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
 417         if (error != 0)
 418                 return (error);
 419 #ifdef MAC
 420         error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg);
 421         if (error != 0)
 422                 return (error);
 423 #endif
 424         for (i = 0; i < shminfo.shmseg; i++) {
 425                 if (shmmap_s->shmid == -1)
 426                         break;
 427                 shmmap_s++;
 428         }
 429         if (i >= shminfo.shmseg)
 430                 return (EMFILE);
 431         size = round_page(shmseg->u.shm_segsz);
 432         prot = VM_PROT_READ;
 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         } else {
 443                 /*
 444                  * This is just a hint to vm_map_find() about where to
 445                  * put it.
 446                  */
 447                 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr +
 448                     lim_max(td, RLIMIT_DATA));
 449         }
 450
 451         vm_object_reference(shmseg->object);
 452         rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object, 0, &attach_va,
 453             size, 0, shmaddr != NULL ? VMFS_NO_SPACE : VMFS_OPTIMAL_SPACE,
 454             prot, prot, MAP_INHERIT_SHARE | MAP_PREFAULT_PARTIAL);
 455         if (rv != KERN_SUCCESS) {
 456                 vm_object_deallocate(shmseg->object);
 457                 return (ENOMEM);
 458         }
 459
 460         shmmap_s->va = attach_va;
 461         shmmap_s->shmid = shmid;
 462         shmseg->u.shm_lpid = p->p_pid;
 463         shmseg->u.shm_atime = time_second;
 464         shmseg->u.shm_nattch++;
 465         td->td_retval[0] = attach_va;
 466         return (error);
 467 }
 468
 469 int
 470 kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg)
 471 {
 472         int error;
 473
 474         SYSVSHM_LOCK();
 475         error = kern_shmat_locked(td, shmid, shmaddr, shmflg);
 476         SYSVSHM_UNLOCK();
 477         return (error);
 478 }
 479
 480 #ifndef _SYS_SYSPROTO_H_
 481 struct shmat_args {
 482         int shmid;
 483         const void *shmaddr;
 484         int shmflg;
 485 };
 486 #endif
 487 int
 488 sys_shmat(struct thread *td, struct shmat_args *uap)
 489 {
 490
 491         return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg));
 492 }
 493
 494 static int
 495 kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf,
 496     size_t *bufsz)
 497 {
 498         struct prison *rpr;
 499         struct shmid_kernel *shmseg;
 500         struct shmid_ds *shmidp;
 501         struct shm_info shm_info;
 502         int error;
 503
 504         SYSVSHM_ASSERT_LOCKED();
 505
 506         rpr = shm_find_prison(td->td_ucred);
 507         if (rpr == NULL)
 508                 return (ENOSYS);
 509
 510         AUDIT_ARG_SVIPC_ID(shmid);
 511         AUDIT_ARG_SVIPC_CMD(cmd);
 512
 513         switch (cmd) {
 514         /*
 515          * It is possible that kern_shmctl is being called from the Linux ABI
 516          * layer, in which case, we will need to implement IPC_INFO.  It should
 517          * be noted that other shmctl calls will be funneled through here for
 518          * Linix binaries as well.
 519          *
 520          * NB: The Linux ABI layer will convert this data to structure(s) more
 521          * consistent with the Linux ABI.
 522          */
 523         case IPC_INFO:
 524                 memcpy(buf, &shminfo, sizeof(shminfo));
 525                 if (bufsz)
 526                         *bufsz = sizeof(shminfo);
 527                 td->td_retval[0] = shmalloced;
 528                 return (0);
 529         case SHM_INFO: {
 530                 shm_info.used_ids = shm_nused;
 531                 shm_info.shm_rss = 0;   /*XXX where to get from ? */
 532                 shm_info.shm_tot = 0;   /*XXX where to get from ? */
 533                 shm_info.shm_swp = 0;   /*XXX where to get from ? */
 534                 shm_info.swap_attempts = 0;     /*XXX where to get from ? */
 535                 shm_info.swap_successes = 0;    /*XXX where to get from ? */
 536                 memcpy(buf, &shm_info, sizeof(shm_info));
 537                 if (bufsz != NULL)
 538                         *bufsz = sizeof(shm_info);
 539                 td->td_retval[0] = shmalloced;
 540                 return (0);
 541         }
 542         }
 543         shmseg = shm_find_segment(rpr, shmid, cmd != SHM_STAT);
 544         if (shmseg == NULL)
 545                 return (EINVAL);
 546 #ifdef MAC
 547         error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd);
 548         if (error != 0)
 549                 return (error);
 550 #endif
 551         switch (cmd) {
 552         case SHM_STAT:
 553         case IPC_STAT:
 554                 shmidp = (struct shmid_ds *)buf;
 555                 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
 556                 if (error != 0)
 557                         return (error);
 558                 memcpy(shmidp, &shmseg->u, sizeof(struct shmid_ds));
 559                 if (td->td_ucred->cr_prison != shmseg->cred->cr_prison)
 560                         shmidp->shm_perm.key = IPC_PRIVATE;
 561                 if (bufsz != NULL)
 562                         *bufsz = sizeof(struct shmid_ds);
 563                 if (cmd == SHM_STAT) {
 564                         td->td_retval[0] = IXSEQ_TO_IPCID(shmid,
 565                             shmseg->u.shm_perm);
 566                 }
 567                 break;
 568         case IPC_SET:
 569                 shmidp = (struct shmid_ds *)buf;
 570                 AUDIT_ARG_SVIPC_PERM(&shmidp->shm_perm);
 571                 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
 572                 if (error != 0)
 573                         return (error);
 574                 shmseg->u.shm_perm.uid = shmidp->shm_perm.uid;
 575                 shmseg->u.shm_perm.gid = shmidp->shm_perm.gid;
 576                 shmseg->u.shm_perm.mode =
 577                     (shmseg->u.shm_perm.mode & ~ACCESSPERMS) |
 578                     (shmidp->shm_perm.mode & ACCESSPERMS);
 579                 shmseg->u.shm_ctime = time_second;
 580                 break;
 581         case IPC_RMID:
 582                 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
 583                 if (error != 0)
 584                         return (error);
 585                 shm_remove(shmseg, IPCID_TO_IX(shmid));
 586                 break;
 587 #if 0
 588         case SHM_LOCK:
 589         case SHM_UNLOCK:
 590 #endif
 591         default:
 592                 error = EINVAL;
 593                 break;
 594         }
 595         return (error);
 596 }
 597
 598 int
 599 kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz)
 600 {
 601         int error;
 602
 603         SYSVSHM_LOCK();
 604         error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz);
 605         SYSVSHM_UNLOCK();
 606         return (error);
 607 }
 608
 609
 610 #ifndef _SYS_SYSPROTO_H_
 611 struct shmctl_args {
 612         int shmid;
 613         int cmd;
 614         struct shmid_ds *buf;
 615 };
 616 #endif
 617 int
 618 sys_shmctl(struct thread *td, struct shmctl_args *uap)
 619 {
 620         int error;
 621         struct shmid_ds buf;
 622         size_t bufsz;
 623
 624         /*
 625          * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
 626          * Linux binaries.  If we see the call come through the FreeBSD ABI,
 627          * return an error back to the user since we do not to support this.
 628          */
 629         if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
 630             uap->cmd == SHM_STAT)
 631                 return (EINVAL);
 632
 633         /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
 634         if (uap->cmd == IPC_SET) {
 635                 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds))))
 636                         goto done;
 637         }
 638
 639         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
 640         if (error)
 641                 goto done;
 642
 643         /* Cases in which we need to copyout */
 644         switch (uap->cmd) {
 645         case IPC_STAT:
 646                 error = copyout(&buf, uap->buf, bufsz);
 647                 break;
 648         }
 649
 650 done:
 651         if (error) {
 652                 /* Invalidate the return value */
 653                 td->td_retval[0] = -1;
 654         }
 655         return (error);
 656 }
 657
 658
 659 static int
 660 shmget_existing(struct thread *td, struct shmget_args *uap, int mode,
 661     int segnum)
 662 {
 663         struct shmid_kernel *shmseg;
 664 #ifdef MAC
 665         int error;
 666 #endif
 667
 668         SYSVSHM_ASSERT_LOCKED();
 669         KASSERT(segnum >= 0 && segnum < shmalloced,
 670             ("segnum %d shmalloced %d", segnum, shmalloced));
 671         shmseg = &shmsegs[segnum];
 672         if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
 673                 return (EEXIST);
 674 #ifdef MAC
 675         error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg);
 676         if (error != 0)
 677                 return (error);
 678 #endif
 679         if (uap->size != 0 && uap->size > shmseg->u.shm_segsz)
 680                 return (EINVAL);
 681         td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
 682         return (0);
 683 }
 684
 685 static int
 686 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode)
 687 {
 688         struct ucred *cred = td->td_ucred;
 689         struct shmid_kernel *shmseg;
 690         vm_object_t shm_object;
 691         int i, segnum;
 692         size_t size;
 693
 694         SYSVSHM_ASSERT_LOCKED();
 695
 696         if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
 697                 return (EINVAL);
 698         if (shm_nused >= shminfo.shmmni) /* Any shmids left? */
 699                 return (ENOSPC);
 700         size = round_page(uap->size);
 701         if (shm_committed + btoc(size) > shminfo.shmall)
 702                 return (ENOMEM);
 703         if (shm_last_free < 0) {
 704                 shmrealloc();   /* Maybe expand the shmsegs[] array. */
 705                 for (i = 0; i < shmalloced; i++)
 706                         if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE)
 707                                 break;
 708                 if (i == shmalloced)
 709                         return (ENOSPC);
 710                 segnum = i;
 711         } else  {
 712                 segnum = shm_last_free;
 713                 shm_last_free = -1;
 714         }
 715         KASSERT(segnum >= 0 && segnum < shmalloced,
 716             ("segnum %d shmalloced %d", segnum, shmalloced));
 717         shmseg = &shmsegs[segnum];
 718 #ifdef RACCT
 719         if (racct_enable) {
 720                 PROC_LOCK(td->td_proc);
 721                 if (racct_add(td->td_proc, RACCT_NSHM, 1)) {
 722                         PROC_UNLOCK(td->td_proc);
 723                         return (ENOSPC);
 724                 }
 725                 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) {
 726                         racct_sub(td->td_proc, RACCT_NSHM, 1);
 727                         PROC_UNLOCK(td->td_proc);
 728                         return (ENOMEM);
 729                 }
 730                 PROC_UNLOCK(td->td_proc);
 731         }
 732 #endif
 733
 734         /*
 735          * We make sure that we have allocated a pager before we need
 736          * to.
 737          */
 738         shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP,
 739             0, size, VM_PROT_DEFAULT, 0, cred);
 740         if (shm_object == NULL) {
 741 #ifdef RACCT
 742                 if (racct_enable) {
 743                         PROC_LOCK(td->td_proc);
 744                         racct_sub(td->td_proc, RACCT_NSHM, 1);
 745                         racct_sub(td->td_proc, RACCT_SHMSIZE, size);
 746                         PROC_UNLOCK(td->td_proc);
 747                 }
 748 #endif
 749                 return (ENOMEM);
 750         }
 751         shm_object->pg_color = 0;
 752         VM_OBJECT_WLOCK(shm_object);
 753         vm_object_clear_flag(shm_object, OBJ_ONEMAPPING);
 754         vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT);
 755         VM_OBJECT_WUNLOCK(shm_object);
 756
 757         shmseg->object = shm_object;
 758         shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid;
 759         shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid;
 760         shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
 761         shmseg->u.shm_perm.key = uap->key;
 762         shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff;
 763         shmseg->cred = crhold(cred);
 764         shmseg->u.shm_segsz = uap->size;
 765         shmseg->u.shm_cpid = td->td_proc->p_pid;
 766         shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0;
 767         shmseg->u.shm_atime = shmseg->u.shm_dtime = 0;
 768 #ifdef MAC
 769         mac_sysvshm_create(cred, shmseg);
 770 #endif
 771         shmseg->u.shm_ctime = time_second;
 772         shm_committed += btoc(size);
 773         shm_nused++;
 774         td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
 775
 776         return (0);
 777 }
 778
 779 #ifndef _SYS_SYSPROTO_H_
 780 struct shmget_args {
 781         key_t key;
 782         size_t size;
 783         int shmflg;
 784 };
 785 #endif
 786 int
 787 sys_shmget(struct thread *td, struct shmget_args *uap)
 788 {
 789         int segnum, mode;
 790         int error;
 791
 792         if (shm_find_prison(td->td_ucred) == NULL)
 793                 return (ENOSYS);
 794         mode = uap->shmflg & ACCESSPERMS;
 795         SYSVSHM_LOCK();
 796         if (uap->key == IPC_PRIVATE) {
 797                 error = shmget_allocate_segment(td, uap, mode);
 798         } else {
 799                 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison,
 800                     uap->key);
 801                 if (segnum >= 0)
 802                         error = shmget_existing(td, uap, mode, segnum);
 803                 else if ((uap->shmflg & IPC_CREAT) == 0)
 804                         error = ENOENT;
 805                 else
 806                         error = shmget_allocate_segment(td, uap, mode);
 807         }
 808         SYSVSHM_UNLOCK();
 809         return (error);
 810 }
 811
 812 static void
 813 shmfork_myhook(struct proc *p1, struct proc *p2)
 814 {
 815         struct shmmap_state *shmmap_s;
 816         size_t size;
 817         int i;
 818
 819         SYSVSHM_LOCK();
 820         size = shminfo.shmseg * sizeof(struct shmmap_state);
 821         shmmap_s = malloc(size, M_SHM, M_WAITOK);
 822         bcopy(p1->p_vmspace->vm_shm, shmmap_s, size);
 823         p2->p_vmspace->vm_shm = shmmap_s;
 824         for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
 825                 if (shmmap_s->shmid != -1) {
 826                         KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 &&
 827                             IPCID_TO_IX(shmmap_s->shmid) < shmalloced,
 828                             ("segnum %d shmalloced %d",
 829                             IPCID_TO_IX(shmmap_s->shmid), shmalloced));
 830                         shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++;
 831                 }
 832         }
 833         SYSVSHM_UNLOCK();
 834 }
 835
 836 static void
 837 shmexit_myhook(struct vmspace *vm)
 838 {
 839         struct shmmap_state *base, *shm;
 840         int i;
 841
 842         base = vm->vm_shm;
 843         if (base != NULL) {
 844                 vm->vm_shm = NULL;
 845                 SYSVSHM_LOCK();
 846                 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) {
 847                         if (shm->shmid != -1)
 848                                 shm_delete_mapping(vm, shm);
 849                 }
 850                 SYSVSHM_UNLOCK();
 851                 free(base, M_SHM);
 852         }
 853 }
 854
 855 static void
 856 shmrealloc(void)
 857 {
 858         struct shmid_kernel *newsegs;
 859         int i;
 860
 861         SYSVSHM_ASSERT_LOCKED();
 862
 863         if (shmalloced >= shminfo.shmmni)
 864                 return;
 865
 866         newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK);
 867         for (i = 0; i < shmalloced; i++)
 868                 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
 869         for (; i < shminfo.shmmni; i++) {
 870                 newsegs[i].u.shm_perm.mode = SHMSEG_FREE;
 871                 newsegs[i].u.shm_perm.seq = 0;
 872 #ifdef MAC
 873                 mac_sysvshm_init(&newsegs[i]);
 874 #endif
 875         }
 876         free(shmsegs, M_SHM);
 877         shmsegs = newsegs;
 878         shmalloced = shminfo.shmmni;
 879 }
 880
 881 static struct syscall_helper_data shm_syscalls[] = {
 882         SYSCALL_INIT_HELPER(shmat),
 883         SYSCALL_INIT_HELPER(shmctl),
 884         SYSCALL_INIT_HELPER(shmdt),
 885         SYSCALL_INIT_HELPER(shmget),
 886 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 887     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 888         SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl),
 889 #endif
 890 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
 891         SYSCALL_INIT_HELPER(shmsys),
 892 #endif
 893         SYSCALL_INIT_LAST
 894 };
 895
 896 #ifdef COMPAT_FREEBSD32
 897 #include <compat/freebsd32/freebsd32.h>
 898 #include <compat/freebsd32/freebsd32_ipc.h>
 899 #include <compat/freebsd32/freebsd32_proto.h>
 900 #include <compat/freebsd32/freebsd32_signal.h>
 901 #include <compat/freebsd32/freebsd32_syscall.h>
 902 #include <compat/freebsd32/freebsd32_util.h>
 903
 904 static struct syscall_helper_data shm32_syscalls[] = {
 905         SYSCALL32_INIT_HELPER_COMPAT(shmat),
 906         SYSCALL32_INIT_HELPER_COMPAT(shmdt),
 907         SYSCALL32_INIT_HELPER_COMPAT(shmget),
 908         SYSCALL32_INIT_HELPER(freebsd32_shmsys),
 909         SYSCALL32_INIT_HELPER(freebsd32_shmctl),
 910 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 911     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 912         SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl),
 913 #endif
 914         SYSCALL_INIT_LAST
 915 };
 916 #endif
 917
 918 static int
 919 shminit(void)
 920 {
 921         struct prison *pr;
 922         void **rsv;
 923         int i, error;
 924         osd_method_t methods[PR_MAXMETHOD] = {
 925             [PR_METHOD_CHECK] =         shm_prison_check,
 926             [PR_METHOD_SET] =           shm_prison_set,
 927             [PR_METHOD_GET] =           shm_prison_get,
 928             [PR_METHOD_REMOVE] =        shm_prison_remove,
 929         };
 930
 931 #ifndef BURN_BRIDGES
 932         if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0)
 933                 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n");
 934 #endif
 935         if (shminfo.shmmax == SHMMAX) {
 936                 /* Initialize shmmax dealing with possible overflow. */
 937                 for (i = PAGE_SIZE; i != 0; i--) {
 938                         shminfo.shmmax = shminfo.shmall * i;
 939                         if ((shminfo.shmmax / shminfo.shmall) == (u_long)i)
 940                                 break;
 941                 }
 942         }
 943         shmalloced = shminfo.shmmni;
 944         shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK);
 945         for (i = 0; i < shmalloced; i++) {
 946                 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE;
 947                 shmsegs[i].u.shm_perm.seq = 0;
 948 #ifdef MAC
 949                 mac_sysvshm_init(&shmsegs[i]);
 950 #endif
 951         }
 952         shm_last_free = 0;
 953         shm_nused = 0;
 954         shm_committed = 0;
 955         sx_init(&sysvshmsx, "sysvshmsx");
 956         shmexit_hook = &shmexit_myhook;
 957         shmfork_hook = &shmfork_myhook;
 958
 959         /* Set current prisons according to their allow.sysvipc. */
 960         shm_prison_slot = osd_jail_register(NULL, methods);
 961         rsv = osd_reserve(shm_prison_slot);
 962         prison_lock(&prison0);
 963         (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0);
 964         prison_unlock(&prison0);
 965         rsv = NULL;
 966         sx_slock(&allprison_lock);
 967         TAILQ_FOREACH(pr, &allprison, pr_list) {
 968                 if (rsv == NULL)
 969                         rsv = osd_reserve(shm_prison_slot);
 970                 prison_lock(pr);
 971                 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) {
 972                         (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
 973                             &prison0);
 974                         rsv = NULL;
 975                 }
 976                 prison_unlock(pr);
 977         }
 978         if (rsv != NULL)
 979                 osd_free_reserved(rsv);
 980         sx_sunlock(&allprison_lock);
 981
 982         error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD);
 983         if (error != 0)
 984                 return (error);
 985 #ifdef COMPAT_FREEBSD32
 986         error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD);
 987         if (error != 0)
 988                 return (error);
 989 #endif
 990         return (0);
 991 }
 992
 993 static int
 994 shmunload(void)
 995 {
 996         int i;
 997
 998         if (shm_nused > 0)
 999                 return (EBUSY);
1000
1001 #ifdef COMPAT_FREEBSD32
1002         syscall32_helper_unregister(shm32_syscalls);
1003 #endif
1004         syscall_helper_unregister(shm_syscalls);
1005         if (shm_prison_slot != 0)
1006                 osd_jail_deregister(shm_prison_slot);
1007
1008         for (i = 0; i < shmalloced; i++) {
1009 #ifdef MAC
1010                 mac_sysvshm_destroy(&shmsegs[i]);
1011 #endif
1012                 /*
1013                  * Objects might be still mapped into the processes
1014                  * address spaces.  Actual free would happen on the
1015                  * last mapping destruction.
1016                  */
1017                 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE)
1018                         vm_object_deallocate(shmsegs[i].object);
1019         }
1020         free(shmsegs, M_SHM);
1021         shmexit_hook = NULL;
1022         shmfork_hook = NULL;
1023         sx_destroy(&sysvshmsx);
1024         return (0);
1025 }
1026
1027 static int
1028 sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
1029 {
1030         struct shmid_kernel tshmseg;
1031         struct prison *pr, *rpr;
1032         int error, i;
1033
1034         SYSVSHM_LOCK();
1035         pr = req->td->td_ucred->cr_prison;
1036         rpr = shm_find_prison(req->td->td_ucred);
1037         error = 0;
1038         for (i = 0; i < shmalloced; i++) {
1039                 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
1040                     rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) {
1041                         bzero(&tshmseg, sizeof(tshmseg));
1042                         tshmseg.u.shm_perm.mode = SHMSEG_FREE;
1043                 } else {
1044                         tshmseg = shmsegs[i];
1045                         if (tshmseg.cred->cr_prison != pr)
1046                                 tshmseg.u.shm_perm.key = IPC_PRIVATE;
1047                 }
1048                 error = SYSCTL_OUT(req, &tshmseg, sizeof(tshmseg));
1049                 if (error != 0)
1050                         break;
1051         }
1052         SYSVSHM_UNLOCK();
1053         return (error);
1054 }
1055
1056 static int
1057 shm_prison_check(void *obj, void *data)
1058 {
1059         struct prison *pr = obj;
1060         struct prison *prpr;
1061         struct vfsoptlist *opts = data;
1062         int error, jsys;
1063
1064         /*
1065          * sysvshm is a jailsys integer.
1066          * It must be "disable" if the parent jail is disabled.
1067          */
1068         error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys));
1069         if (error != ENOENT) {
1070                 if (error != 0)
1071                         return (error);
1072                 switch (jsys) {
1073                 case JAIL_SYS_DISABLE:
1074                         break;
1075                 case JAIL_SYS_NEW:
1076                 case JAIL_SYS_INHERIT:
1077                         prison_lock(pr->pr_parent);
1078                         prpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1079                         prison_unlock(pr->pr_parent);
1080                         if (prpr == NULL)
1081                                 return (EPERM);
1082                         break;
1083                 default:
1084                         return (EINVAL);
1085                 }
1086         }
1087
1088         return (0);
1089 }
1090
1091 static int
1092 shm_prison_set(void *obj, void *data)
1093 {
1094         struct prison *pr = obj;
1095         struct prison *tpr, *orpr, *nrpr, *trpr;
1096         struct vfsoptlist *opts = data;
1097         void *rsv;
1098         int jsys, descend;
1099
1100         /*
1101          * sysvshm controls which jail is the root of the associated segments
1102          * (this jail or same as the parent), or if the feature is available
1103          * at all.
1104          */
1105         if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT)
1106                 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
1107                     ? JAIL_SYS_INHERIT
1108                     : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
1109                     ? JAIL_SYS_DISABLE
1110                     : -1;
1111         if (jsys == JAIL_SYS_DISABLE) {
1112                 prison_lock(pr);
1113                 orpr = osd_jail_get(pr, shm_prison_slot);
1114                 if (orpr != NULL)
1115                         osd_jail_del(pr, shm_prison_slot);
1116                 prison_unlock(pr);
1117                 if (orpr != NULL) {
1118                         if (orpr == pr)
1119                                 shm_prison_cleanup(pr);
1120                         /* Disable all child jails as well. */
1121                         FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1122                                 prison_lock(tpr);
1123                                 trpr = osd_jail_get(tpr, shm_prison_slot);
1124                                 if (trpr != NULL) {
1125                                         osd_jail_del(tpr, shm_prison_slot);
1126                                         prison_unlock(tpr);
1127                                         if (trpr == tpr)
1128                                                 shm_prison_cleanup(tpr);
1129                                 } else {
1130                                         prison_unlock(tpr);
1131                                         descend = 0;
1132                                 }
1133                         }
1134                 }
1135         } else if (jsys != -1) {
1136                 if (jsys == JAIL_SYS_NEW)
1137                         nrpr = pr;
1138                 else {
1139                         prison_lock(pr->pr_parent);
1140                         nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1141                         prison_unlock(pr->pr_parent);
1142                 }
1143                 rsv = osd_reserve(shm_prison_slot);
1144                 prison_lock(pr);
1145                 orpr = osd_jail_get(pr, shm_prison_slot);
1146                 if (orpr != nrpr)
1147                         (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
1148                             nrpr);
1149                 else
1150                         osd_free_reserved(rsv);
1151                 prison_unlock(pr);
1152                 if (orpr != nrpr) {
1153                         if (orpr == pr)
1154                                 shm_prison_cleanup(pr);
1155                         if (orpr != NULL) {
1156                                 /* Change child jails matching the old root, */
1157                                 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1158                                         prison_lock(tpr);
1159                                         trpr = osd_jail_get(tpr,
1160                                             shm_prison_slot);
1161                                         if (trpr == orpr) {
1162                                                 (void)osd_jail_set(tpr,
1163                                                     shm_prison_slot, nrpr);
1164                                                 prison_unlock(tpr);
1165                                                 if (trpr == tpr)
1166                                                         shm_prison_cleanup(tpr);
1167                                         } else {
1168                                                 prison_unlock(tpr);
1169                                                 descend = 0;
1170                                         }
1171                                 }
1172                         }
1173                 }
1174         }
1175
1176         return (0);
1177 }
1178
1179 static int
1180 shm_prison_get(void *obj, void *data)
1181 {
1182         struct prison *pr = obj;
1183         struct prison *rpr;
1184         struct vfsoptlist *opts = data;
1185         int error, jsys;
1186
1187         /* Set sysvshm based on the jail's root prison. */
1188         prison_lock(pr);
1189         rpr = osd_jail_get(pr, shm_prison_slot);
1190         prison_unlock(pr);
1191         jsys = rpr == NULL ? JAIL_SYS_DISABLE
1192             : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
1193         error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys));
1194         if (error == ENOENT)
1195                 error = 0;
1196         return (error);
1197 }
1198
1199 static int
1200 shm_prison_remove(void *obj, void *data __unused)
1201 {
1202         struct prison *pr = obj;
1203         struct prison *rpr;
1204
1205         SYSVSHM_LOCK();
1206         prison_lock(pr);
1207         rpr = osd_jail_get(pr, shm_prison_slot);
1208         prison_unlock(pr);
1209         if (rpr == pr)
1210                 shm_prison_cleanup(pr);
1211         SYSVSHM_UNLOCK();
1212         return (0);
1213 }
1214
1215 static void
1216 shm_prison_cleanup(struct prison *pr)
1217 {
1218         struct shmid_kernel *shmseg;
1219         int i;
1220
1221         /* Remove any segments that belong to this jail. */
1222         for (i = 0; i < shmalloced; i++) {
1223                 shmseg = &shmsegs[i];
1224                 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) &&
1225                     shmseg->cred != NULL && shmseg->cred->cr_prison == pr) {
1226                         shm_remove(shmseg, i);
1227                 }
1228         }
1229 }
1230
1231 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory");
1232
1233 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
1234 struct oshmid_ds {
1235         struct  ipc_perm_old shm_perm;  /* operation perms */
1236         int     shm_segsz;              /* size of segment (bytes) */
1237         u_short shm_cpid;               /* pid, creator */
1238         u_short shm_lpid;               /* pid, last operation */
1239         short   shm_nattch;             /* no. of current attaches */
1240         time_t  shm_atime;              /* last attach time */
1241         time_t  shm_dtime;              /* last detach time */
1242         time_t  shm_ctime;              /* last change time */
1243         void    *shm_handle;            /* internal handle for shm segment */
1244 };
1245
1246 struct oshmctl_args {
1247         int shmid;
1248         int cmd;
1249         struct oshmid_ds *ubuf;
1250 };
1251
1252 static int
1253 oshmctl(struct thread *td, struct oshmctl_args *uap)
1254 {
1255 #ifdef COMPAT_43
1256         int error = 0;
1257         struct prison *rpr;
1258         struct shmid_kernel *shmseg;
1259         struct oshmid_ds outbuf;
1260
1261         rpr = shm_find_prison(td->td_ucred);
1262         if (rpr == NULL)
1263                 return (ENOSYS);
1264         if (uap->cmd != IPC_STAT) {
1265                 return (freebsd7_shmctl(td,
1266                     (struct freebsd7_shmctl_args *)uap));
1267         }
1268         SYSVSHM_LOCK();
1269         shmseg = shm_find_segment(rpr, uap->shmid, true);
1270         if (shmseg == NULL) {
1271                 SYSVSHM_UNLOCK();
1272                 return (EINVAL);
1273         }
1274         error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
1275         if (error != 0) {
1276                 SYSVSHM_UNLOCK();
1277                 return (error);
1278         }
1279 #ifdef MAC
1280         error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd);
1281         if (error != 0) {
1282                 SYSVSHM_UNLOCK();
1283                 return (error);
1284         }
1285 #endif
1286         ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm);
1287         outbuf.shm_segsz = shmseg->u.shm_segsz;
1288         outbuf.shm_cpid = shmseg->u.shm_cpid;
1289         outbuf.shm_lpid = shmseg->u.shm_lpid;
1290         outbuf.shm_nattch = shmseg->u.shm_nattch;
1291         outbuf.shm_atime = shmseg->u.shm_atime;
1292         outbuf.shm_dtime = shmseg->u.shm_dtime;
1293         outbuf.shm_ctime = shmseg->u.shm_ctime;
1294         outbuf.shm_handle = shmseg->object;
1295         SYSVSHM_UNLOCK();
1296         return (copyout(&outbuf, uap->ubuf, sizeof(outbuf)));
1297 #else
1298         return (EINVAL);
1299 #endif
1300 }
1301
1302 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1303 static sy_call_t *shmcalls[] = {
1304         (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl,
1305         (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget,
1306         (sy_call_t *)freebsd7_shmctl
1307 };
1308
1309 #ifndef _SYS_SYSPROTO_H_
1310 /* XXX actually varargs. */
1311 struct shmsys_args {
1312         int     which;
1313         int     a2;
1314         int     a3;
1315         int     a4;
1316 };
1317 #endif
1318 int
1319 sys_shmsys(struct thread *td, struct shmsys_args *uap)
1320 {
1321
1322         AUDIT_ARG_SVIPC_WHICH(uap->which);
1323         if (uap->which < 0 || uap->which >= nitems(shmcalls))
1324                 return (EINVAL);
1325         return ((*shmcalls[uap->which])(td, &uap->a2));
1326 }
1327
1328 #endif  /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */
1329
1330 #ifdef COMPAT_FREEBSD32
1331
1332 int
1333 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap)
1334 {
1335
1336 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1337     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1338         AUDIT_ARG_SVIPC_WHICH(uap->which);
1339         switch (uap->which) {
1340         case 0: {       /* shmat */
1341                 struct shmat_args ap;
1342
1343                 ap.shmid = uap->a2;
1344                 ap.shmaddr = PTRIN(uap->a3);
1345                 ap.shmflg = uap->a4;
1346                 return (sysent[SYS_shmat].sy_call(td, &ap));
1347         }
1348         case 2: {       /* shmdt */
1349                 struct shmdt_args ap;
1350
1351                 ap.shmaddr = PTRIN(uap->a2);
1352                 return (sysent[SYS_shmdt].sy_call(td, &ap));
1353         }
1354         case 3: {       /* shmget */
1355                 struct shmget_args ap;
1356
1357                 ap.key = uap->a2;
1358                 ap.size = uap->a3;
1359                 ap.shmflg = uap->a4;
1360                 return (sysent[SYS_shmget].sy_call(td, &ap));
1361         }
1362         case 4: {       /* shmctl */
1363                 struct freebsd7_freebsd32_shmctl_args ap;
1364
1365                 ap.shmid = uap->a2;
1366                 ap.cmd = uap->a3;
1367                 ap.buf = PTRIN(uap->a4);
1368                 return (freebsd7_freebsd32_shmctl(td, &ap));
1369         }
1370         case 1:         /* oshmctl */
1371         default:
1372                 return (EINVAL);
1373         }
1374 #else
1375         return (nosys(td, NULL));
1376 #endif
1377 }
1378
1379 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1380     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1381 int
1382 freebsd7_freebsd32_shmctl(struct thread *td,
1383     struct freebsd7_freebsd32_shmctl_args *uap)
1384 {
1385         int error;
1386         union {
1387                 struct shmid_ds shmid_ds;
1388                 struct shm_info shm_info;
1389                 struct shminfo shminfo;
1390         } u;
1391         union {
1392                 struct shmid_ds32_old shmid_ds32;
1393                 struct shm_info32 shm_info32;
1394                 struct shminfo32 shminfo32;
1395         } u32;
1396         size_t sz;
1397
1398         if (uap->cmd == IPC_SET) {
1399                 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1400                     sizeof(u32.shmid_ds32))))
1401                         goto done;
1402                 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm,
1403                     &u.shmid_ds.shm_perm);
1404                 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1405                 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1406                 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1407                 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1408                 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1409                 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1410                 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1411         }
1412
1413         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1414         if (error)
1415                 goto done;
1416
1417         /* Cases in which we need to copyout */
1418         switch (uap->cmd) {
1419         case IPC_INFO:
1420                 CP(u.shminfo, u32.shminfo32, shmmax);
1421                 CP(u.shminfo, u32.shminfo32, shmmin);
1422                 CP(u.shminfo, u32.shminfo32, shmmni);
1423                 CP(u.shminfo, u32.shminfo32, shmseg);
1424                 CP(u.shminfo, u32.shminfo32, shmall);
1425                 error = copyout(&u32.shminfo32, uap->buf,
1426                     sizeof(u32.shminfo32));
1427                 break;
1428         case SHM_INFO:
1429                 CP(u.shm_info, u32.shm_info32, used_ids);
1430                 CP(u.shm_info, u32.shm_info32, shm_rss);
1431                 CP(u.shm_info, u32.shm_info32, shm_tot);
1432                 CP(u.shm_info, u32.shm_info32, shm_swp);
1433                 CP(u.shm_info, u32.shm_info32, swap_attempts);
1434                 CP(u.shm_info, u32.shm_info32, swap_successes);
1435                 error = copyout(&u32.shm_info32, uap->buf,
1436                     sizeof(u32.shm_info32));
1437                 break;
1438         case SHM_STAT:
1439         case IPC_STAT:
1440                 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm,
1441                     &u32.shmid_ds32.shm_perm);
1442                 if (u.shmid_ds.shm_segsz > INT32_MAX)
1443                         u32.shmid_ds32.shm_segsz = INT32_MAX;
1444                 else
1445                         CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1446                 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1447                 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1448                 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1449                 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1450                 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1451                 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1452                 u32.shmid_ds32.shm_internal = 0;
1453                 error = copyout(&u32.shmid_ds32, uap->buf,
1454                     sizeof(u32.shmid_ds32));
1455                 break;
1456         }
1457
1458 done:
1459         if (error) {
1460                 /* Invalidate the return value */
1461                 td->td_retval[0] = -1;
1462         }
1463         return (error);
1464 }
1465 #endif
1466
1467 int
1468 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap)
1469 {
1470         int error;
1471         union {
1472                 struct shmid_ds shmid_ds;
1473                 struct shm_info shm_info;
1474                 struct shminfo shminfo;
1475         } u;
1476         union {
1477                 struct shmid_ds32 shmid_ds32;
1478                 struct shm_info32 shm_info32;
1479                 struct shminfo32 shminfo32;
1480         } u32;
1481         size_t sz;
1482
1483         if (uap->cmd == IPC_SET) {
1484                 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1485                     sizeof(u32.shmid_ds32))))
1486                         goto done;
1487                 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm,
1488                     &u.shmid_ds.shm_perm);
1489                 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1490                 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1491                 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1492                 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1493                 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1494                 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1495                 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1496         }
1497
1498         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1499         if (error)
1500                 goto done;
1501
1502         /* Cases in which we need to copyout */
1503         switch (uap->cmd) {
1504         case IPC_INFO:
1505                 CP(u.shminfo, u32.shminfo32, shmmax);
1506                 CP(u.shminfo, u32.shminfo32, shmmin);
1507                 CP(u.shminfo, u32.shminfo32, shmmni);
1508                 CP(u.shminfo, u32.shminfo32, shmseg);
1509                 CP(u.shminfo, u32.shminfo32, shmall);
1510                 error = copyout(&u32.shminfo32, uap->buf,
1511                     sizeof(u32.shminfo32));
1512                 break;
1513         case SHM_INFO:
1514                 CP(u.shm_info, u32.shm_info32, used_ids);
1515                 CP(u.shm_info, u32.shm_info32, shm_rss);
1516                 CP(u.shm_info, u32.shm_info32, shm_tot);
1517                 CP(u.shm_info, u32.shm_info32, shm_swp);
1518                 CP(u.shm_info, u32.shm_info32, swap_attempts);
1519                 CP(u.shm_info, u32.shm_info32, swap_successes);
1520                 error = copyout(&u32.shm_info32, uap->buf,
1521                     sizeof(u32.shm_info32));
1522                 break;
1523         case SHM_STAT:
1524         case IPC_STAT:
1525                 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm,
1526                     &u32.shmid_ds32.shm_perm);
1527                 if (u.shmid_ds.shm_segsz > INT32_MAX)
1528                         u32.shmid_ds32.shm_segsz = INT32_MAX;
1529                 else
1530                         CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1531                 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1532                 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1533                 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1534                 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1535                 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1536                 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1537                 error = copyout(&u32.shmid_ds32, uap->buf,
1538                     sizeof(u32.shmid_ds32));
1539                 break;
1540         }
1541
1542 done:
1543         if (error) {
1544                 /* Invalidate the return value */
1545                 td->td_retval[0] = -1;
1546         }
1547         return (error);
1548 }
1549 #endif
1550
1551 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1552     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1553
1554 #ifndef CP
1555 #define CP(src, dst, fld)       do { (dst).fld = (src).fld; } while (0)
1556 #endif
1557
1558 #ifndef _SYS_SYSPROTO_H_
1559 struct freebsd7_shmctl_args {
1560         int shmid;
1561         int cmd;
1562         struct shmid_ds_old *buf;
1563 };
1564 #endif
1565 int
1566 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap)
1567 {
1568         int error;
1569         struct shmid_ds_old old;
1570         struct shmid_ds buf;
1571         size_t bufsz;
1572
1573         /*
1574          * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
1575          * Linux binaries.  If we see the call come through the FreeBSD ABI,
1576          * return an error back to the user since we do not to support this.
1577          */
1578         if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
1579             uap->cmd == SHM_STAT)
1580                 return (EINVAL);
1581
1582         /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
1583         if (uap->cmd == IPC_SET) {
1584                 if ((error = copyin(uap->buf, &old, sizeof(old))))
1585                         goto done;
1586                 ipcperm_old2new(&old.shm_perm, &buf.shm_perm);
1587                 CP(old, buf, shm_segsz);
1588                 CP(old, buf, shm_lpid);
1589                 CP(old, buf, shm_cpid);
1590                 CP(old, buf, shm_nattch);
1591                 CP(old, buf, shm_atime);
1592                 CP(old, buf, shm_dtime);
1593                 CP(old, buf, shm_ctime);
1594         }
1595
1596         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
1597         if (error)
1598                 goto done;
1599
1600         /* Cases in which we need to copyout */
1601         switch (uap->cmd) {
1602         case IPC_STAT:
1603                 ipcperm_new2old(&buf.shm_perm, &old.shm_perm);
1604                 if (buf.shm_segsz > INT_MAX)
1605                         old.shm_segsz = INT_MAX;
1606                 else
1607                         CP(buf, old, shm_segsz);
1608                 CP(buf, old, shm_lpid);
1609                 CP(buf, old, shm_cpid);
1610                 if (buf.shm_nattch > SHRT_MAX)
1611                         old.shm_nattch = SHRT_MAX;
1612                 else
1613                         CP(buf, old, shm_nattch);
1614                 CP(buf, old, shm_atime);
1615                 CP(buf, old, shm_dtime);
1616                 CP(buf, old, shm_ctime);
1617                 old.shm_internal = NULL;
1618                 error = copyout(&old, uap->buf, sizeof(old));
1619                 break;
1620         }
1621
1622 done:
1623         if (error) {
1624                 /* Invalidate the return value */
1625                 td->td_retval[0] = -1;
1626         }
1627         return (error);
1628 }
1629
1630 #endif  /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1631            COMPAT_FREEBSD7 */
1632
1633 static int
1634 sysvshm_modload(struct module *module, int cmd, void *arg)
1635 {
1636         int error = 0;
1637
1638         switch (cmd) {
1639         case MOD_LOAD:
1640                 error = shminit();
1641                 if (error != 0)
1642                         shmunload();
1643                 break;
1644         case MOD_UNLOAD:
1645                 error = shmunload();
1646                 break;
1647         case MOD_SHUTDOWN:
1648                 break;
1649         default:
1650                 error = EINVAL;
1651                 break;
1652         }
1653         return (error);
1654 }
1655
1656 static moduledata_t sysvshm_mod = {
1657         "sysvshm",
1658         &sysvshm_modload,
1659         NULL
1660 };
1661
1662 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
1663 MODULE_VERSION(sysvshm, 1);