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     "Array of struct shmid_kernel for each potential shared memory segment");
 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,
 848             M_WAITOK | M_ZERO);
 849         for (i = 0; i < shmalloced; i++)
 850                 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
 851         for (; i < shminfo.shmmni; i++) {
 852                 newsegs[i].u.shm_perm.mode = SHMSEG_FREE;
 853                 newsegs[i].u.shm_perm.seq = 0;
 854 #ifdef MAC
 855                 mac_sysvshm_init(&newsegs[i]);
 856 #endif
 857         }
 858         free(shmsegs, M_SHM);
 859         shmsegs = newsegs;
 860         shmalloced = shminfo.shmmni;
 861 }
 862
 863 static struct syscall_helper_data shm_syscalls[] = {
 864         SYSCALL_INIT_HELPER(shmat),
 865         SYSCALL_INIT_HELPER(shmctl),
 866         SYSCALL_INIT_HELPER(shmdt),
 867         SYSCALL_INIT_HELPER(shmget),
 868 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 869     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 870         SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl),
 871 #endif
 872 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
 873         SYSCALL_INIT_HELPER(shmsys),
 874 #endif
 875         SYSCALL_INIT_LAST
 876 };
 877
 878 #ifdef COMPAT_FREEBSD32
 879 #include <compat/freebsd32/freebsd32.h>
 880 #include <compat/freebsd32/freebsd32_ipc.h>
 881 #include <compat/freebsd32/freebsd32_proto.h>
 882 #include <compat/freebsd32/freebsd32_signal.h>
 883 #include <compat/freebsd32/freebsd32_syscall.h>
 884 #include <compat/freebsd32/freebsd32_util.h>
 885
 886 static struct syscall_helper_data shm32_syscalls[] = {
 887         SYSCALL32_INIT_HELPER_COMPAT(shmat),
 888         SYSCALL32_INIT_HELPER_COMPAT(shmdt),
 889         SYSCALL32_INIT_HELPER_COMPAT(shmget),
 890         SYSCALL32_INIT_HELPER(freebsd32_shmsys),
 891         SYSCALL32_INIT_HELPER(freebsd32_shmctl),
 892 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 893     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 894         SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl),
 895 #endif
 896         SYSCALL_INIT_LAST
 897 };
 898 #endif
 899
 900 static int
 901 shminit(void)
 902 {
 903         struct prison *pr;
 904         void **rsv;
 905         int i, error;
 906         osd_method_t methods[PR_MAXMETHOD] = {
 907             [PR_METHOD_CHECK] =         shm_prison_check,
 908             [PR_METHOD_SET] =           shm_prison_set,
 909             [PR_METHOD_GET] =           shm_prison_get,
 910             [PR_METHOD_REMOVE] =        shm_prison_remove,
 911         };
 912
 913 #ifndef BURN_BRIDGES
 914         if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0)
 915                 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n");
 916 #endif
 917         if (shminfo.shmmax == SHMMAX) {
 918                 /* Initialize shmmax dealing with possible overflow. */
 919                 for (i = PAGE_SIZE; i != 0; i--) {
 920                         shminfo.shmmax = shminfo.shmall * i;
 921                         if ((shminfo.shmmax / shminfo.shmall) == (u_long)i)
 922                                 break;
 923                 }
 924         }
 925         shmalloced = shminfo.shmmni;
 926         shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM,
 927             M_WAITOK|M_ZERO);
 928         for (i = 0; i < shmalloced; i++) {
 929                 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE;
 930                 shmsegs[i].u.shm_perm.seq = 0;
 931 #ifdef MAC
 932                 mac_sysvshm_init(&shmsegs[i]);
 933 #endif
 934         }
 935         shm_last_free = 0;
 936         shm_nused = 0;
 937         shm_committed = 0;
 938         sx_init(&sysvshmsx, "sysvshmsx");
 939         shmexit_hook = &shmexit_myhook;
 940         shmfork_hook = &shmfork_myhook;
 941
 942         /* Set current prisons according to their allow.sysvipc. */
 943         shm_prison_slot = osd_jail_register(NULL, methods);
 944         rsv = osd_reserve(shm_prison_slot);
 945         prison_lock(&prison0);
 946         (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0);
 947         prison_unlock(&prison0);
 948         rsv = NULL;
 949         sx_slock(&allprison_lock);
 950         TAILQ_FOREACH(pr, &allprison, pr_list) {
 951                 if (rsv == NULL)
 952                         rsv = osd_reserve(shm_prison_slot);
 953                 prison_lock(pr);
 954                 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) {
 955                         (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
 956                             &prison0);
 957                         rsv = NULL;
 958                 }
 959                 prison_unlock(pr);
 960         }
 961         if (rsv != NULL)
 962                 osd_free_reserved(rsv);
 963         sx_sunlock(&allprison_lock);
 964
 965         error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD);
 966         if (error != 0)
 967                 return (error);
 968 #ifdef COMPAT_FREEBSD32
 969         error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD);
 970         if (error != 0)
 971                 return (error);
 972 #endif
 973         return (0);
 974 }
 975
 976 static int
 977 shmunload(void)
 978 {
 979         int i;
 980
 981         if (shm_nused > 0)
 982                 return (EBUSY);
 983
 984 #ifdef COMPAT_FREEBSD32
 985         syscall32_helper_unregister(shm32_syscalls);
 986 #endif
 987         syscall_helper_unregister(shm_syscalls);
 988         if (shm_prison_slot != 0)
 989                 osd_jail_deregister(shm_prison_slot);
 990
 991         for (i = 0; i < shmalloced; i++) {
 992 #ifdef MAC
 993                 mac_sysvshm_destroy(&shmsegs[i]);
 994 #endif
 995                 /*
 996                  * Objects might be still mapped into the processes
 997                  * address spaces.  Actual free would happen on the
 998                  * last mapping destruction.
 999                  */
1000                 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE)
1001                         vm_object_deallocate(shmsegs[i].object);
1002         }
1003         free(shmsegs, M_SHM);
1004         shmexit_hook = NULL;
1005         shmfork_hook = NULL;
1006         sx_destroy(&sysvshmsx);
1007         return (0);
1008 }
1009
1010 static int
1011 sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
1012 {
1013         struct shmid_kernel tshmseg;
1014 #ifdef COMPAT_FREEBSD32
1015         struct shmid_kernel32 tshmseg32;
1016 #endif
1017         struct prison *pr, *rpr;
1018         void *outaddr;
1019         size_t outsize;
1020         int error, i;
1021
1022         SYSVSHM_LOCK();
1023         pr = req->td->td_ucred->cr_prison;
1024         rpr = shm_find_prison(req->td->td_ucred);
1025         error = 0;
1026         for (i = 0; i < shmalloced; i++) {
1027                 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
1028                     rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) {
1029                         bzero(&tshmseg, sizeof(tshmseg));
1030                         tshmseg.u.shm_perm.mode = SHMSEG_FREE;
1031                 } else {
1032                         tshmseg = shmsegs[i];
1033                         if (tshmseg.cred->cr_prison != pr)
1034                                 tshmseg.u.shm_perm.key = IPC_PRIVATE;
1035                 }
1036 #ifdef COMPAT_FREEBSD32
1037                 if (SV_CURPROC_FLAG(SV_ILP32)) {
1038                         bzero(&tshmseg32, sizeof(tshmseg32));
1039                         freebsd32_ipcperm_out(&tshmseg.u.shm_perm,
1040                             &tshmseg32.u.shm_perm);
1041                         CP(tshmseg, tshmseg32, u.shm_segsz);
1042                         CP(tshmseg, tshmseg32, u.shm_lpid);
1043                         CP(tshmseg, tshmseg32, u.shm_cpid);
1044                         CP(tshmseg, tshmseg32, u.shm_nattch);
1045                         CP(tshmseg, tshmseg32, u.shm_atime);
1046                         CP(tshmseg, tshmseg32, u.shm_dtime);
1047                         CP(tshmseg, tshmseg32, u.shm_ctime);
1048                         /* Don't copy object, label, or cred */
1049                         outaddr = &tshmseg32;
1050                         outsize = sizeof(tshmseg32);
1051                 } else
1052 #endif
1053                 {
1054                         tshmseg.object = NULL;
1055                         tshmseg.label = NULL;
1056                         tshmseg.cred = NULL;
1057                         outaddr = &tshmseg;
1058                         outsize = sizeof(tshmseg);
1059                 }
1060                 error = SYSCTL_OUT(req, outaddr, outsize);
1061                 if (error != 0)
1062                         break;
1063         }
1064         SYSVSHM_UNLOCK();
1065         return (error);
1066 }
1067
1068 static int
1069 shm_prison_check(void *obj, void *data)
1070 {
1071         struct prison *pr = obj;
1072         struct prison *prpr;
1073         struct vfsoptlist *opts = data;
1074         int error, jsys;
1075
1076         /*
1077          * sysvshm is a jailsys integer.
1078          * It must be "disable" if the parent jail is disabled.
1079          */
1080         error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys));
1081         if (error != ENOENT) {
1082                 if (error != 0)
1083                         return (error);
1084                 switch (jsys) {
1085                 case JAIL_SYS_DISABLE:
1086                         break;
1087                 case JAIL_SYS_NEW:
1088                 case JAIL_SYS_INHERIT:
1089                         prison_lock(pr->pr_parent);
1090                         prpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1091                         prison_unlock(pr->pr_parent);
1092                         if (prpr == NULL)
1093                                 return (EPERM);
1094                         break;
1095                 default:
1096                         return (EINVAL);
1097                 }
1098         }
1099
1100         return (0);
1101 }
1102
1103 static int
1104 shm_prison_set(void *obj, void *data)
1105 {
1106         struct prison *pr = obj;
1107         struct prison *tpr, *orpr, *nrpr, *trpr;
1108         struct vfsoptlist *opts = data;
1109         void *rsv;
1110         int jsys, descend;
1111
1112         /*
1113          * sysvshm controls which jail is the root of the associated segments
1114          * (this jail or same as the parent), or if the feature is available
1115          * at all.
1116          */
1117         if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT)
1118                 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
1119                     ? JAIL_SYS_INHERIT
1120                     : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
1121                     ? JAIL_SYS_DISABLE
1122                     : -1;
1123         if (jsys == JAIL_SYS_DISABLE) {
1124                 prison_lock(pr);
1125                 orpr = osd_jail_get(pr, shm_prison_slot);
1126                 if (orpr != NULL)
1127                         osd_jail_del(pr, shm_prison_slot);
1128                 prison_unlock(pr);
1129                 if (orpr != NULL) {
1130                         if (orpr == pr)
1131                                 shm_prison_cleanup(pr);
1132                         /* Disable all child jails as well. */
1133                         FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1134                                 prison_lock(tpr);
1135                                 trpr = osd_jail_get(tpr, shm_prison_slot);
1136                                 if (trpr != NULL) {
1137                                         osd_jail_del(tpr, shm_prison_slot);
1138                                         prison_unlock(tpr);
1139                                         if (trpr == tpr)
1140                                                 shm_prison_cleanup(tpr);
1141                                 } else {
1142                                         prison_unlock(tpr);
1143                                         descend = 0;
1144                                 }
1145                         }
1146                 }
1147         } else if (jsys != -1) {
1148                 if (jsys == JAIL_SYS_NEW)
1149                         nrpr = pr;
1150                 else {
1151                         prison_lock(pr->pr_parent);
1152                         nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1153                         prison_unlock(pr->pr_parent);
1154                 }
1155                 rsv = osd_reserve(shm_prison_slot);
1156                 prison_lock(pr);
1157                 orpr = osd_jail_get(pr, shm_prison_slot);
1158                 if (orpr != nrpr)
1159                         (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
1160                             nrpr);
1161                 else
1162                         osd_free_reserved(rsv);
1163                 prison_unlock(pr);
1164                 if (orpr != nrpr) {
1165                         if (orpr == pr)
1166                                 shm_prison_cleanup(pr);
1167                         if (orpr != NULL) {
1168                                 /* Change child jails matching the old root, */
1169                                 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1170                                         prison_lock(tpr);
1171                                         trpr = osd_jail_get(tpr,
1172                                             shm_prison_slot);
1173                                         if (trpr == orpr) {
1174                                                 (void)osd_jail_set(tpr,
1175                                                     shm_prison_slot, nrpr);
1176                                                 prison_unlock(tpr);
1177                                                 if (trpr == tpr)
1178                                                         shm_prison_cleanup(tpr);
1179                                         } else {
1180                                                 prison_unlock(tpr);
1181                                                 descend = 0;
1182                                         }
1183                                 }
1184                         }
1185                 }
1186         }
1187
1188         return (0);
1189 }
1190
1191 static int
1192 shm_prison_get(void *obj, void *data)
1193 {
1194         struct prison *pr = obj;
1195         struct prison *rpr;
1196         struct vfsoptlist *opts = data;
1197         int error, jsys;
1198
1199         /* Set sysvshm based on the jail's root prison. */
1200         prison_lock(pr);
1201         rpr = osd_jail_get(pr, shm_prison_slot);
1202         prison_unlock(pr);
1203         jsys = rpr == NULL ? JAIL_SYS_DISABLE
1204             : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
1205         error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys));
1206         if (error == ENOENT)
1207                 error = 0;
1208         return (error);
1209 }
1210
1211 static int
1212 shm_prison_remove(void *obj, void *data __unused)
1213 {
1214         struct prison *pr = obj;
1215         struct prison *rpr;
1216
1217         SYSVSHM_LOCK();
1218         prison_lock(pr);
1219         rpr = osd_jail_get(pr, shm_prison_slot);
1220         prison_unlock(pr);
1221         if (rpr == pr)
1222                 shm_prison_cleanup(pr);
1223         SYSVSHM_UNLOCK();
1224         return (0);
1225 }
1226
1227 static void
1228 shm_prison_cleanup(struct prison *pr)
1229 {
1230         struct shmid_kernel *shmseg;
1231         int i;
1232
1233         /* Remove any segments that belong to this jail. */
1234         for (i = 0; i < shmalloced; i++) {
1235                 shmseg = &shmsegs[i];
1236                 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) &&
1237                     shmseg->cred != NULL && shmseg->cred->cr_prison == pr) {
1238                         shm_remove(shmseg, i);
1239                 }
1240         }
1241 }
1242
1243 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory");
1244
1245 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
1246 struct oshmid_ds {
1247         struct  ipc_perm_old shm_perm;  /* operation perms */
1248         int     shm_segsz;              /* size of segment (bytes) */
1249         u_short shm_cpid;               /* pid, creator */
1250         u_short shm_lpid;               /* pid, last operation */
1251         short   shm_nattch;             /* no. of current attaches */
1252         time_t  shm_atime;              /* last attach time */
1253         time_t  shm_dtime;              /* last detach time */
1254         time_t  shm_ctime;              /* last change time */
1255         void    *shm_handle;            /* internal handle for shm segment */
1256 };
1257
1258 struct oshmctl_args {
1259         int shmid;
1260         int cmd;
1261         struct oshmid_ds *ubuf;
1262 };
1263
1264 static int
1265 oshmctl(struct thread *td, struct oshmctl_args *uap)
1266 {
1267 #ifdef COMPAT_43
1268         int error = 0;
1269         struct prison *rpr;
1270         struct shmid_kernel *shmseg;
1271         struct oshmid_ds outbuf;
1272
1273         rpr = shm_find_prison(td->td_ucred);
1274         if (rpr == NULL)
1275                 return (ENOSYS);
1276         if (uap->cmd != IPC_STAT) {
1277                 return (freebsd7_shmctl(td,
1278                     (struct freebsd7_shmctl_args *)uap));
1279         }
1280         SYSVSHM_LOCK();
1281         shmseg = shm_find_segment(rpr, uap->shmid, true);
1282         if (shmseg == NULL) {
1283                 SYSVSHM_UNLOCK();
1284                 return (EINVAL);
1285         }
1286         error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
1287         if (error != 0) {
1288                 SYSVSHM_UNLOCK();
1289                 return (error);
1290         }
1291 #ifdef MAC
1292         error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd);
1293         if (error != 0) {
1294                 SYSVSHM_UNLOCK();
1295                 return (error);
1296         }
1297 #endif
1298         ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm);
1299         outbuf.shm_segsz = shmseg->u.shm_segsz;
1300         outbuf.shm_cpid = shmseg->u.shm_cpid;
1301         outbuf.shm_lpid = shmseg->u.shm_lpid;
1302         outbuf.shm_nattch = shmseg->u.shm_nattch;
1303         outbuf.shm_atime = shmseg->u.shm_atime;
1304         outbuf.shm_dtime = shmseg->u.shm_dtime;
1305         outbuf.shm_ctime = shmseg->u.shm_ctime;
1306         outbuf.shm_handle = shmseg->object;
1307         SYSVSHM_UNLOCK();
1308         return (copyout(&outbuf, uap->ubuf, sizeof(outbuf)));
1309 #else
1310         return (EINVAL);
1311 #endif
1312 }
1313
1314 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1315 static sy_call_t *shmcalls[] = {
1316         (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl,
1317         (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget,
1318         (sy_call_t *)freebsd7_shmctl
1319 };
1320
1321 #ifndef _SYS_SYSPROTO_H_
1322 /* XXX actually varargs. */
1323 struct shmsys_args {
1324         int     which;
1325         int     a2;
1326         int     a3;
1327         int     a4;
1328 };
1329 #endif
1330 int
1331 sys_shmsys(struct thread *td, struct shmsys_args *uap)
1332 {
1333
1334         if (uap->which < 0 || uap->which >= nitems(shmcalls))
1335                 return (EINVAL);
1336         return ((*shmcalls[uap->which])(td, &uap->a2));
1337 }
1338
1339 #endif  /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */
1340
1341 #ifdef COMPAT_FREEBSD32
1342
1343 int
1344 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap)
1345 {
1346
1347 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1348     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1349         switch (uap->which) {
1350         case 0: {       /* shmat */
1351                 struct shmat_args ap;
1352
1353                 ap.shmid = uap->a2;
1354                 ap.shmaddr = PTRIN(uap->a3);
1355                 ap.shmflg = uap->a4;
1356                 return (sysent[SYS_shmat].sy_call(td, &ap));
1357         }
1358         case 2: {       /* shmdt */
1359                 struct shmdt_args ap;
1360
1361                 ap.shmaddr = PTRIN(uap->a2);
1362                 return (sysent[SYS_shmdt].sy_call(td, &ap));
1363         }
1364         case 3: {       /* shmget */
1365                 struct shmget_args ap;
1366
1367                 ap.key = uap->a2;
1368                 ap.size = uap->a3;
1369                 ap.shmflg = uap->a4;
1370                 return (sysent[SYS_shmget].sy_call(td, &ap));
1371         }
1372         case 4: {       /* shmctl */
1373                 struct freebsd7_freebsd32_shmctl_args ap;
1374
1375                 ap.shmid = uap->a2;
1376                 ap.cmd = uap->a3;
1377                 ap.buf = PTRIN(uap->a4);
1378                 return (freebsd7_freebsd32_shmctl(td, &ap));
1379         }
1380         case 1:         /* oshmctl */
1381         default:
1382                 return (EINVAL);
1383         }
1384 #else
1385         return (nosys(td, NULL));
1386 #endif
1387 }
1388
1389 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1390     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1391 int
1392 freebsd7_freebsd32_shmctl(struct thread *td,
1393     struct freebsd7_freebsd32_shmctl_args *uap)
1394 {
1395         int error;
1396         union {
1397                 struct shmid_ds shmid_ds;
1398                 struct shm_info shm_info;
1399                 struct shminfo shminfo;
1400         } u;
1401         union {
1402                 struct shmid_ds32_old shmid_ds32;
1403                 struct shm_info32 shm_info32;
1404                 struct shminfo32 shminfo32;
1405         } u32;
1406         size_t sz;
1407
1408         if (uap->cmd == IPC_SET) {
1409                 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1410                     sizeof(u32.shmid_ds32))))
1411                         goto done;
1412                 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm,
1413                     &u.shmid_ds.shm_perm);
1414                 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1415                 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1416                 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1417                 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1418                 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1419                 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1420                 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1421         }
1422
1423         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1424         if (error)
1425                 goto done;
1426
1427         /* Cases in which we need to copyout */
1428         switch (uap->cmd) {
1429         case IPC_INFO:
1430                 CP(u.shminfo, u32.shminfo32, shmmax);
1431                 CP(u.shminfo, u32.shminfo32, shmmin);
1432                 CP(u.shminfo, u32.shminfo32, shmmni);
1433                 CP(u.shminfo, u32.shminfo32, shmseg);
1434                 CP(u.shminfo, u32.shminfo32, shmall);
1435                 error = copyout(&u32.shminfo32, uap->buf,
1436                     sizeof(u32.shminfo32));
1437                 break;
1438         case SHM_INFO:
1439                 CP(u.shm_info, u32.shm_info32, used_ids);
1440                 CP(u.shm_info, u32.shm_info32, shm_rss);
1441                 CP(u.shm_info, u32.shm_info32, shm_tot);
1442                 CP(u.shm_info, u32.shm_info32, shm_swp);
1443                 CP(u.shm_info, u32.shm_info32, swap_attempts);
1444                 CP(u.shm_info, u32.shm_info32, swap_successes);
1445                 error = copyout(&u32.shm_info32, uap->buf,
1446                     sizeof(u32.shm_info32));
1447                 break;
1448         case SHM_STAT:
1449         case IPC_STAT:
1450                 memset(&u32.shmid_ds32, 0, sizeof(u32.shmid_ds32));
1451                 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm,
1452                     &u32.shmid_ds32.shm_perm);
1453                 if (u.shmid_ds.shm_segsz > INT32_MAX)
1454                         u32.shmid_ds32.shm_segsz = INT32_MAX;
1455                 else
1456                         CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1457                 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1458                 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1459                 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1460                 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1461                 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1462                 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1463                 u32.shmid_ds32.shm_internal = 0;
1464                 error = copyout(&u32.shmid_ds32, uap->buf,
1465                     sizeof(u32.shmid_ds32));
1466                 break;
1467         }
1468
1469 done:
1470         if (error) {
1471                 /* Invalidate the return value */
1472                 td->td_retval[0] = -1;
1473         }
1474         return (error);
1475 }
1476 #endif
1477
1478 int
1479 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap)
1480 {
1481         int error;
1482         union {
1483                 struct shmid_ds shmid_ds;
1484                 struct shm_info shm_info;
1485                 struct shminfo shminfo;
1486         } u;
1487         union {
1488                 struct shmid_ds32 shmid_ds32;
1489                 struct shm_info32 shm_info32;
1490                 struct shminfo32 shminfo32;
1491         } u32;
1492         size_t sz;
1493
1494         if (uap->cmd == IPC_SET) {
1495                 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1496                     sizeof(u32.shmid_ds32))))
1497                         goto done;
1498                 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm,
1499                     &u.shmid_ds.shm_perm);
1500                 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1501                 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1502                 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1503                 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1504                 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1505                 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1506                 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1507         }
1508
1509         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1510         if (error)
1511                 goto done;
1512
1513         /* Cases in which we need to copyout */
1514         switch (uap->cmd) {
1515         case IPC_INFO:
1516                 CP(u.shminfo, u32.shminfo32, shmmax);
1517                 CP(u.shminfo, u32.shminfo32, shmmin);
1518                 CP(u.shminfo, u32.shminfo32, shmmni);
1519                 CP(u.shminfo, u32.shminfo32, shmseg);
1520                 CP(u.shminfo, u32.shminfo32, shmall);
1521                 error = copyout(&u32.shminfo32, uap->buf,
1522                     sizeof(u32.shminfo32));
1523                 break;
1524         case SHM_INFO:
1525                 CP(u.shm_info, u32.shm_info32, used_ids);
1526                 CP(u.shm_info, u32.shm_info32, shm_rss);
1527                 CP(u.shm_info, u32.shm_info32, shm_tot);
1528                 CP(u.shm_info, u32.shm_info32, shm_swp);
1529                 CP(u.shm_info, u32.shm_info32, swap_attempts);
1530                 CP(u.shm_info, u32.shm_info32, swap_successes);
1531                 error = copyout(&u32.shm_info32, uap->buf,
1532                     sizeof(u32.shm_info32));
1533                 break;
1534         case SHM_STAT:
1535         case IPC_STAT:
1536                 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm,
1537                     &u32.shmid_ds32.shm_perm);
1538                 if (u.shmid_ds.shm_segsz > INT32_MAX)
1539                         u32.shmid_ds32.shm_segsz = INT32_MAX;
1540                 else
1541                         CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1542                 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1543                 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1544                 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1545                 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1546                 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1547                 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1548                 error = copyout(&u32.shmid_ds32, uap->buf,
1549                     sizeof(u32.shmid_ds32));
1550                 break;
1551         }
1552
1553 done:
1554         if (error) {
1555                 /* Invalidate the return value */
1556                 td->td_retval[0] = -1;
1557         }
1558         return (error);
1559 }
1560 #endif
1561
1562 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1563     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1564
1565 #ifndef CP
1566 #define CP(src, dst, fld)       do { (dst).fld = (src).fld; } while (0)
1567 #endif
1568
1569 #ifndef _SYS_SYSPROTO_H_
1570 struct freebsd7_shmctl_args {
1571         int shmid;
1572         int cmd;
1573         struct shmid_ds_old *buf;
1574 };
1575 #endif
1576 int
1577 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap)
1578 {
1579         int error;
1580         struct shmid_ds_old old;
1581         struct shmid_ds buf;
1582         size_t bufsz;
1583
1584         /*
1585          * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
1586          * Linux binaries.  If we see the call come through the FreeBSD ABI,
1587          * return an error back to the user since we do not to support this.
1588          */
1589         if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
1590             uap->cmd == SHM_STAT)
1591                 return (EINVAL);
1592
1593         /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
1594         if (uap->cmd == IPC_SET) {
1595                 if ((error = copyin(uap->buf, &old, sizeof(old))))
1596                         goto done;
1597                 ipcperm_old2new(&old.shm_perm, &buf.shm_perm);
1598                 CP(old, buf, shm_segsz);
1599                 CP(old, buf, shm_lpid);
1600                 CP(old, buf, shm_cpid);
1601                 CP(old, buf, shm_nattch);
1602                 CP(old, buf, shm_atime);
1603                 CP(old, buf, shm_dtime);
1604                 CP(old, buf, shm_ctime);
1605         }
1606
1607         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
1608         if (error)
1609                 goto done;
1610
1611         /* Cases in which we need to copyout */
1612         switch (uap->cmd) {
1613         case IPC_STAT:
1614                 memset(&old, 0, sizeof(old));
1615                 ipcperm_new2old(&buf.shm_perm, &old.shm_perm);
1616                 if (buf.shm_segsz > INT_MAX)
1617                         old.shm_segsz = INT_MAX;
1618                 else
1619                         CP(buf, old, shm_segsz);
1620                 CP(buf, old, shm_lpid);
1621                 CP(buf, old, shm_cpid);
1622                 if (buf.shm_nattch > SHRT_MAX)
1623                         old.shm_nattch = SHRT_MAX;
1624                 else
1625                         CP(buf, old, shm_nattch);
1626                 CP(buf, old, shm_atime);
1627                 CP(buf, old, shm_dtime);
1628                 CP(buf, old, shm_ctime);
1629                 old.shm_internal = NULL;
1630                 error = copyout(&old, uap->buf, sizeof(old));
1631                 break;
1632         }
1633
1634 done:
1635         if (error) {
1636                 /* Invalidate the return value */
1637                 td->td_retval[0] = -1;
1638         }
1639         return (error);
1640 }
1641
1642 #endif  /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1643            COMPAT_FREEBSD7 */
1644
1645 static int
1646 sysvshm_modload(struct module *module, int cmd, void *arg)
1647 {
1648         int error = 0;
1649
1650         switch (cmd) {
1651         case MOD_LOAD:
1652                 error = shminit();
1653                 if (error != 0)
1654                         shmunload();
1655                 break;
1656         case MOD_UNLOAD:
1657                 error = shmunload();
1658                 break;
1659         case MOD_SHUTDOWN:
1660                 break;
1661         default:
1662                 error = EINVAL;
1663                 break;
1664         }
1665         return (error);
1666 }
1667
1668 static moduledata_t sysvshm_mod = {
1669         "sysvshm",
1670         &sysvshm_modload,
1671         NULL
1672 };
1673
1674 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
1675 MODULE_VERSION(sysvshm, 1);