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