sys/kern/sysv_shm.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-4-Clause AND BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 1994 Adam Glass and Charles Hannum.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. All advertising materials mentioning features or use of this software
  15  *    must display the following acknowledgement:
  16  *      This product includes software developed by Adam Glass and Charles
  17  *      Hannum.
  18  * 4. The names of the authors may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
  22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  24  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * $NetBSD: sysv_shm.c,v 1.39 1997/10/07 10:02:03 drochner Exp $
  33  */
  34 /*-
  35  * Copyright (c) 2003-2005 McAfee, Inc.
  36  * Copyright (c) 2016-2017 Robert N. M. Watson
  37  * All rights reserved.
  38  *
  39  * This software was developed for the FreeBSD Project in part by McAfee
  40  * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR
  41  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research
  42  * program.
  43  *
  44  * Portions of this software were developed by BAE Systems, the University of
  45  * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL
  46  * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent
  47  * Computing (TC) research program.
  48  *
  49  * Redistribution and use in source and binary forms, with or without
  50  * modification, are permitted provided that the following conditions
  51  * are met:
  52  * 1. Redistributions of source code must retain the above copyright
  53  *    notice, this list of conditions and the following disclaimer.
  54  * 2. Redistributions in binary form must reproduce the above copyright
  55  *    notice, this list of conditions and the following disclaimer in the
  56  *    documentation and/or other materials provided with the distribution.
  57  *
  58  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  68  * SUCH DAMAGE.
  69  */
  70
  71 #include <sys/cdefs.h>
  72 __FBSDID("$FreeBSD$");
  73
  74 #include "opt_sysvipc.h"
  75
  76 #include <sys/param.h>
  77 #include <sys/systm.h>
  78 #include <sys/kernel.h>
  79 #include <sys/limits.h>
  80 #include <sys/lock.h>
  81 #include <sys/sysctl.h>
  82 #include <sys/shm.h>
  83 #include <sys/proc.h>
  84 #include <sys/malloc.h>
  85 #include <sys/mman.h>
  86 #include <sys/module.h>
  87 #include <sys/mutex.h>
  88 #include <sys/racct.h>
  89 #include <sys/resourcevar.h>
  90 #include <sys/rwlock.h>
  91 #include <sys/stat.h>
  92 #include <sys/syscall.h>
  93 #include <sys/syscallsubr.h>
  94 #include <sys/sysent.h>
  95 #include <sys/sysproto.h>
  96 #include <sys/jail.h>
  97
  98 #include <security/audit/audit.h>
  99 #include <security/mac/mac_framework.h>
 100
 101 #include <vm/vm.h>
 102 #include <vm/vm_param.h>
 103 #include <vm/pmap.h>
 104 #include <vm/vm_object.h>
 105 #include <vm/vm_map.h>
 106 #include <vm/vm_page.h>
 107 #include <vm/vm_pager.h>
 108
 109 FEATURE(sysv_shm, "System V shared memory segments support");
 110
 111 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
 112
 113 static int shmget_allocate_segment(struct thread *td,
 114     struct shmget_args *uap, int mode);
 115 static int shmget_existing(struct thread *td, struct shmget_args *uap,
 116     int mode, int segnum);
 117
 118 #define SHMSEG_FREE             0x0200
 119 #define SHMSEG_REMOVED          0x0400
 120 #define SHMSEG_ALLOCATED        0x0800
 121
 122 static int shm_last_free, shm_nused, shmalloced;
 123 vm_size_t shm_committed;
 124 static struct shmid_kernel *shmsegs;
 125 static unsigned shm_prison_slot;
 126
 127 struct shmmap_state {
 128         vm_offset_t va;
 129         int shmid;
 130 };
 131
 132 static void shm_deallocate_segment(struct shmid_kernel *);
 133 static int shm_find_segment_by_key(struct prison *, key_t);
 134 static struct shmid_kernel *shm_find_segment(struct prison *, int, bool);
 135 static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *);
 136 static void shmrealloc(void);
 137 static int shminit(void);
 138 static int sysvshm_modload(struct module *, int, void *);
 139 static int shmunload(void);
 140 static void shmexit_myhook(struct vmspace *vm);
 141 static void shmfork_myhook(struct proc *p1, struct proc *p2);
 142 static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS);
 143 static void shm_remove(struct shmid_kernel *, int);
 144 static struct prison *shm_find_prison(struct ucred *);
 145 static int shm_prison_cansee(struct prison *, struct shmid_kernel *);
 146 static int shm_prison_check(void *, void *);
 147 static int shm_prison_set(void *, void *);
 148 static int shm_prison_get(void *, void *);
 149 static int shm_prison_remove(void *, void *);
 150 static void shm_prison_cleanup(struct prison *);
 151
 152 /*
 153  * Tuneable values.
 154  */
 155 #ifndef SHMMAXPGS
 156 #define SHMMAXPGS       131072  /* Note: sysv shared memory is swap backed. */
 157 #endif
 158 #ifndef SHMMAX
 159 #define SHMMAX  (SHMMAXPGS*PAGE_SIZE)
 160 #endif
 161 #ifndef SHMMIN
 162 #define SHMMIN  1
 163 #endif
 164 #ifndef SHMMNI
 165 #define SHMMNI  192
 166 #endif
 167 #ifndef SHMSEG
 168 #define SHMSEG  128
 169 #endif
 170 #ifndef SHMALL
 171 #define SHMALL  (SHMMAXPGS)
 172 #endif
 173
 174 struct  shminfo shminfo = {
 175         .shmmax = SHMMAX,
 176         .shmmin = SHMMIN,
 177         .shmmni = SHMMNI,
 178         .shmseg = SHMSEG,
 179         .shmall = SHMALL
 180 };
 181
 182 static int shm_use_phys;
 183 static int shm_allow_removed = 1;
 184
 185 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RWTUN, &shminfo.shmmax, 0,
 186     "Maximum shared memory segment size");
 187 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RWTUN, &shminfo.shmmin, 0,
 188     "Minimum shared memory segment size");
 189 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0,
 190     "Number of shared memory identifiers");
 191 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0,
 192     "Number of segments per process");
 193 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RWTUN, &shminfo.shmall, 0,
 194     "Maximum number of pages available for shared memory");
 195 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RWTUN,
 196     &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core");
 197 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RWTUN,
 198     &shm_allow_removed, 0,
 199     "Enable/Disable attachment to attached segments marked for removal");
 200 SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD |
 201     CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "",
 202     "Array of struct shmid_kernel for each potential shared memory segment");
 203
 204 static struct sx sysvshmsx;
 205 #define SYSVSHM_LOCK()          sx_xlock(&sysvshmsx)
 206 #define SYSVSHM_UNLOCK()        sx_xunlock(&sysvshmsx)
 207 #define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED)
 208
 209 static int
 210 shm_find_segment_by_key(struct prison *pr, key_t key)
 211 {
 212         int i;
 213
 214         for (i = 0; i < shmalloced; i++)
 215                 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) &&
 216                     shmsegs[i].cred != NULL &&
 217                     shmsegs[i].cred->cr_prison == pr &&
 218                     shmsegs[i].u.shm_perm.key == key)
 219                         return (i);
 220         return (-1);
 221 }
 222
 223 /*
 224  * Finds segment either by shmid if is_shmid is true, or by segnum if
 225  * is_shmid is false.
 226  */
 227 static struct shmid_kernel *
 228 shm_find_segment(struct prison *rpr, int arg, bool is_shmid)
 229 {
 230         struct shmid_kernel *shmseg;
 231         int segnum;
 232
 233         segnum = is_shmid ? IPCID_TO_IX(arg) : arg;
 234         if (segnum < 0 || segnum >= shmalloced)
 235                 return (NULL);
 236         shmseg = &shmsegs[segnum];
 237         if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
 238             (!shm_allow_removed &&
 239             (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) ||
 240             (is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg)) ||
 241             shm_prison_cansee(rpr, shmseg) != 0)
 242                 return (NULL);
 243         return (shmseg);
 244 }
 245
 246 static void
 247 shm_deallocate_segment(struct shmid_kernel *shmseg)
 248 {
 249         vm_size_t size;
 250
 251         SYSVSHM_ASSERT_LOCKED();
 252
 253         vm_object_deallocate(shmseg->object);
 254         shmseg->object = NULL;
 255         size = round_page(shmseg->u.shm_segsz);
 256         shm_committed -= btoc(size);
 257         shm_nused--;
 258         shmseg->u.shm_perm.mode = SHMSEG_FREE;
 259 #ifdef MAC
 260         mac_sysvshm_cleanup(shmseg);
 261 #endif
 262         racct_sub_cred(shmseg->cred, RACCT_NSHM, 1);
 263         racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size);
 264         crfree(shmseg->cred);
 265         shmseg->cred = NULL;
 266 }
 267
 268 static int
 269 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s)
 270 {
 271         struct shmid_kernel *shmseg;
 272         int segnum, result;
 273         vm_size_t size;
 274
 275         SYSVSHM_ASSERT_LOCKED();
 276         segnum = IPCID_TO_IX(shmmap_s->shmid);
 277         KASSERT(segnum >= 0 && segnum < shmalloced,
 278             ("segnum %d shmalloced %d", segnum, shmalloced));
 279
 280         shmseg = &shmsegs[segnum];
 281         size = round_page(shmseg->u.shm_segsz);
 282         result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size);
 283         if (result != KERN_SUCCESS)
 284                 return (EINVAL);
 285         shmmap_s->shmid = -1;
 286         shmseg->u.shm_dtime = time_second;
 287         if (--shmseg->u.shm_nattch == 0 &&
 288             (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) {
 289                 shm_deallocate_segment(shmseg);
 290                 shm_last_free = segnum;
 291         }
 292         return (0);
 293 }
 294
 295 static void
 296 shm_remove(struct shmid_kernel *shmseg, int segnum)
 297 {
 298
 299         shmseg->u.shm_perm.key = IPC_PRIVATE;
 300         shmseg->u.shm_perm.mode |= SHMSEG_REMOVED;
 301         if (shmseg->u.shm_nattch == 0) {
 302                 shm_deallocate_segment(shmseg);
 303                 shm_last_free = segnum;
 304         }
 305 }
 306
 307 static struct prison *
 308 shm_find_prison(struct ucred *cred)
 309 {
 310         struct prison *pr, *rpr;
 311
 312         pr = cred->cr_prison;
 313         prison_lock(pr);
 314         rpr = osd_jail_get(pr, shm_prison_slot);
 315         prison_unlock(pr);
 316         return rpr;
 317 }
 318
 319 static int
 320 shm_prison_cansee(struct prison *rpr, struct shmid_kernel *shmseg)
 321 {
 322
 323         if (shmseg->cred == NULL ||
 324             !(rpr == shmseg->cred->cr_prison ||
 325               prison_ischild(rpr, shmseg->cred->cr_prison)))
 326                 return (EINVAL);
 327         return (0);
 328 }
 329
 330 static int
 331 kern_shmdt_locked(struct thread *td, const void *shmaddr)
 332 {
 333         struct proc *p = td->td_proc;
 334         struct shmmap_state *shmmap_s;
 335 #ifdef MAC
 336         int error;
 337 #endif
 338         int i;
 339
 340         SYSVSHM_ASSERT_LOCKED();
 341         if (shm_find_prison(td->td_ucred) == NULL)
 342                 return (ENOSYS);
 343         shmmap_s = p->p_vmspace->vm_shm;
 344         if (shmmap_s == NULL)
 345                 return (EINVAL);
 346         AUDIT_ARG_SVIPC_ID(shmmap_s->shmid);
 347         for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
 348                 if (shmmap_s->shmid != -1 &&
 349                     shmmap_s->va == (vm_offset_t)shmaddr) {
 350                         break;
 351                 }
 352         }
 353         if (i == shminfo.shmseg)
 354                 return (EINVAL);
 355 #ifdef MAC
 356         error = mac_sysvshm_check_shmdt(td->td_ucred,
 357             &shmsegs[IPCID_TO_IX(shmmap_s->shmid)]);
 358         if (error != 0)
 359                 return (error);
 360 #endif
 361         return (shm_delete_mapping(p->p_vmspace, shmmap_s));
 362 }
 363
 364 #ifndef _SYS_SYSPROTO_H_
 365 struct shmdt_args {
 366         const void *shmaddr;
 367 };
 368 #endif
 369 int
 370 sys_shmdt(struct thread *td, struct shmdt_args *uap)
 371 {
 372         int error;
 373
 374         SYSVSHM_LOCK();
 375         error = kern_shmdt_locked(td, uap->shmaddr);
 376         SYSVSHM_UNLOCK();
 377         return (error);
 378 }
 379
 380 static int
 381 kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr,
 382     int shmflg)
 383 {
 384         struct prison *rpr;
 385         struct proc *p = td->td_proc;
 386         struct shmid_kernel *shmseg;
 387         struct shmmap_state *shmmap_s;
 388         vm_offset_t attach_va;
 389         vm_prot_t prot;
 390         vm_size_t size;
 391         int error, i, rv;
 392
 393         AUDIT_ARG_SVIPC_ID(shmid);
 394         AUDIT_ARG_VALUE(shmflg);
 395
 396         SYSVSHM_ASSERT_LOCKED();
 397         rpr = shm_find_prison(td->td_ucred);
 398         if (rpr == NULL)
 399                 return (ENOSYS);
 400         shmmap_s = p->p_vmspace->vm_shm;
 401         if (shmmap_s == NULL) {
 402                 shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state),
 403                     M_SHM, M_WAITOK);
 404                 for (i = 0; i < shminfo.shmseg; i++)
 405                         shmmap_s[i].shmid = -1;
 406                 KASSERT(p->p_vmspace->vm_shm == NULL, ("raced"));
 407                 p->p_vmspace->vm_shm = shmmap_s;
 408         }
 409         shmseg = shm_find_segment(rpr, shmid, true);
 410         if (shmseg == NULL)
 411                 return (EINVAL);
 412         error = ipcperm(td, &shmseg->u.shm_perm,
 413             (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
 414         if (error != 0)
 415                 return (error);
 416 #ifdef MAC
 417         error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg);
 418         if (error != 0)
 419                 return (error);
 420 #endif
 421         for (i = 0; i < shminfo.shmseg; i++) {
 422                 if (shmmap_s->shmid == -1)
 423                         break;
 424                 shmmap_s++;
 425         }
 426         if (i >= shminfo.shmseg)
 427                 return (EMFILE);
 428         size = round_page(shmseg->u.shm_segsz);
 429         prot = VM_PROT_READ;
 430         if ((shmflg & SHM_RDONLY) == 0)
 431                 prot |= VM_PROT_WRITE;
 432         if (shmaddr != NULL) {
 433                 if ((shmflg & SHM_RND) != 0)
 434                         attach_va = rounddown2((vm_offset_t)shmaddr, SHMLBA);
 435                 else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0)
 436                         attach_va = (vm_offset_t)shmaddr;
 437                 else
 438                         return (EINVAL);
 439         } else {
 440                 /*
 441                  * This is just a hint to vm_map_find() about where to
 442                  * put it.
 443                  */
 444                 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr +
 445                     lim_max(td, RLIMIT_DATA));
 446         }
 447
 448         vm_object_reference(shmseg->object);
 449         rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object, 0, &attach_va,
 450             size, 0, shmaddr != NULL ? VMFS_NO_SPACE : VMFS_OPTIMAL_SPACE,
 451             prot, prot, MAP_INHERIT_SHARE | MAP_PREFAULT_PARTIAL);
 452         if (rv != KERN_SUCCESS) {
 453                 vm_object_deallocate(shmseg->object);
 454                 return (ENOMEM);
 455         }
 456
 457         shmmap_s->va = attach_va;
 458         shmmap_s->shmid = shmid;
 459         shmseg->u.shm_lpid = p->p_pid;
 460         shmseg->u.shm_atime = time_second;
 461         shmseg->u.shm_nattch++;
 462         td->td_retval[0] = attach_va;
 463         return (error);
 464 }
 465
 466 int
 467 kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg)
 468 {
 469         int error;
 470
 471         SYSVSHM_LOCK();
 472         error = kern_shmat_locked(td, shmid, shmaddr, shmflg);
 473         SYSVSHM_UNLOCK();
 474         return (error);
 475 }
 476
 477 #ifndef _SYS_SYSPROTO_H_
 478 struct shmat_args {
 479         int shmid;
 480         const void *shmaddr;
 481         int shmflg;
 482 };
 483 #endif
 484 int
 485 sys_shmat(struct thread *td, struct shmat_args *uap)
 486 {
 487
 488         return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg));
 489 }
 490
 491 static int
 492 kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf,
 493     size_t *bufsz)
 494 {
 495         struct prison *rpr;
 496         struct shmid_kernel *shmseg;
 497         struct shmid_ds *shmidp;
 498         struct shm_info shm_info;
 499         int error;
 500
 501         SYSVSHM_ASSERT_LOCKED();
 502
 503         rpr = shm_find_prison(td->td_ucred);
 504         if (rpr == NULL)
 505                 return (ENOSYS);
 506
 507         AUDIT_ARG_SVIPC_ID(shmid);
 508         AUDIT_ARG_SVIPC_CMD(cmd);
 509
 510         switch (cmd) {
 511         /*
 512          * It is possible that kern_shmctl is being called from the Linux ABI
 513          * layer, in which case, we will need to implement IPC_INFO.  It should
 514          * be noted that other shmctl calls will be funneled through here for
 515          * Linix binaries as well.
 516          *
 517          * NB: The Linux ABI layer will convert this data to structure(s) more
 518          * consistent with the Linux ABI.
 519          */
 520         case IPC_INFO:
 521                 memcpy(buf, &shminfo, sizeof(shminfo));
 522                 if (bufsz)
 523                         *bufsz = sizeof(shminfo);
 524                 td->td_retval[0] = shmalloced;
 525                 return (0);
 526         case SHM_INFO: {
 527                 shm_info.used_ids = shm_nused;
 528                 shm_info.shm_rss = 0;   /*XXX where to get from ? */
 529                 shm_info.shm_tot = 0;   /*XXX where to get from ? */
 530                 shm_info.shm_swp = 0;   /*XXX where to get from ? */
 531                 shm_info.swap_attempts = 0;     /*XXX where to get from ? */
 532                 shm_info.swap_successes = 0;    /*XXX where to get from ? */
 533                 memcpy(buf, &shm_info, sizeof(shm_info));
 534                 if (bufsz != NULL)
 535                         *bufsz = sizeof(shm_info);
 536                 td->td_retval[0] = shmalloced;
 537                 return (0);
 538         }
 539         }
 540         shmseg = shm_find_segment(rpr, shmid, cmd != SHM_STAT);
 541         if (shmseg == NULL)
 542                 return (EINVAL);
 543 #ifdef MAC
 544         error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd);
 545         if (error != 0)
 546                 return (error);
 547 #endif
 548         switch (cmd) {
 549         case SHM_STAT:
 550         case IPC_STAT:
 551                 shmidp = (struct shmid_ds *)buf;
 552                 error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
 553                 if (error != 0)
 554                         return (error);
 555                 memcpy(shmidp, &shmseg->u, sizeof(struct shmid_ds));
 556                 if (td->td_ucred->cr_prison != shmseg->cred->cr_prison)
 557                         shmidp->shm_perm.key = IPC_PRIVATE;
 558                 if (bufsz != NULL)
 559                         *bufsz = sizeof(struct shmid_ds);
 560                 if (cmd == SHM_STAT) {
 561                         td->td_retval[0] = IXSEQ_TO_IPCID(shmid,
 562                             shmseg->u.shm_perm);
 563                 }
 564                 break;
 565         case IPC_SET:
 566                 shmidp = (struct shmid_ds *)buf;
 567                 AUDIT_ARG_SVIPC_PERM(&shmidp->shm_perm);
 568                 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
 569                 if (error != 0)
 570                         return (error);
 571                 shmseg->u.shm_perm.uid = shmidp->shm_perm.uid;
 572                 shmseg->u.shm_perm.gid = shmidp->shm_perm.gid;
 573                 shmseg->u.shm_perm.mode =
 574                     (shmseg->u.shm_perm.mode & ~ACCESSPERMS) |
 575                     (shmidp->shm_perm.mode & ACCESSPERMS);
 576                 shmseg->u.shm_ctime = time_second;
 577                 break;
 578         case IPC_RMID:
 579                 error = ipcperm(td, &shmseg->u.shm_perm, IPC_M);
 580                 if (error != 0)
 581                         return (error);
 582                 shm_remove(shmseg, IPCID_TO_IX(shmid));
 583                 break;
 584 #if 0
 585         case SHM_LOCK:
 586         case SHM_UNLOCK:
 587 #endif
 588         default:
 589                 error = EINVAL;
 590                 break;
 591         }
 592         return (error);
 593 }
 594
 595 int
 596 kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz)
 597 {
 598         int error;
 599
 600         SYSVSHM_LOCK();
 601         error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz);
 602         SYSVSHM_UNLOCK();
 603         return (error);
 604 }
 605
 606
 607 #ifndef _SYS_SYSPROTO_H_
 608 struct shmctl_args {
 609         int shmid;
 610         int cmd;
 611         struct shmid_ds *buf;
 612 };
 613 #endif
 614 int
 615 sys_shmctl(struct thread *td, struct shmctl_args *uap)
 616 {
 617         int error;
 618         struct shmid_ds buf;
 619         size_t bufsz;
 620
 621         /*
 622          * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
 623          * Linux binaries.  If we see the call come through the FreeBSD ABI,
 624          * return an error back to the user since we do not to support this.
 625          */
 626         if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
 627             uap->cmd == SHM_STAT)
 628                 return (EINVAL);
 629
 630         /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
 631         if (uap->cmd == IPC_SET) {
 632                 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds))))
 633                         goto done;
 634         }
 635
 636         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
 637         if (error)
 638                 goto done;
 639
 640         /* Cases in which we need to copyout */
 641         switch (uap->cmd) {
 642         case IPC_STAT:
 643                 error = copyout(&buf, uap->buf, bufsz);
 644                 break;
 645         }
 646
 647 done:
 648         if (error) {
 649                 /* Invalidate the return value */
 650                 td->td_retval[0] = -1;
 651         }
 652         return (error);
 653 }
 654
 655
 656 static int
 657 shmget_existing(struct thread *td, struct shmget_args *uap, int mode,
 658     int segnum)
 659 {
 660         struct shmid_kernel *shmseg;
 661 #ifdef MAC
 662         int error;
 663 #endif
 664
 665         SYSVSHM_ASSERT_LOCKED();
 666         KASSERT(segnum >= 0 && segnum < shmalloced,
 667             ("segnum %d shmalloced %d", segnum, shmalloced));
 668         shmseg = &shmsegs[segnum];
 669         if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
 670                 return (EEXIST);
 671 #ifdef MAC
 672         error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg);
 673         if (error != 0)
 674                 return (error);
 675 #endif
 676         if (uap->size != 0 && uap->size > shmseg->u.shm_segsz)
 677                 return (EINVAL);
 678         td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
 679         return (0);
 680 }
 681
 682 static int
 683 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode)
 684 {
 685         struct ucred *cred = td->td_ucred;
 686         struct shmid_kernel *shmseg;
 687         vm_object_t shm_object;
 688         int i, segnum;
 689         size_t size;
 690
 691         SYSVSHM_ASSERT_LOCKED();
 692
 693         if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
 694                 return (EINVAL);
 695         if (shm_nused >= shminfo.shmmni) /* Any shmids left? */
 696                 return (ENOSPC);
 697         size = round_page(uap->size);
 698         if (shm_committed + btoc(size) > shminfo.shmall)
 699                 return (ENOMEM);
 700         if (shm_last_free < 0) {
 701                 shmrealloc();   /* Maybe expand the shmsegs[] array. */
 702                 for (i = 0; i < shmalloced; i++)
 703                         if (shmsegs[i].u.shm_perm.mode & SHMSEG_FREE)
 704                                 break;
 705                 if (i == shmalloced)
 706                         return (ENOSPC);
 707                 segnum = i;
 708         } else  {
 709                 segnum = shm_last_free;
 710                 shm_last_free = -1;
 711         }
 712         KASSERT(segnum >= 0 && segnum < shmalloced,
 713             ("segnum %d shmalloced %d", segnum, shmalloced));
 714         shmseg = &shmsegs[segnum];
 715 #ifdef RACCT
 716         if (racct_enable) {
 717                 PROC_LOCK(td->td_proc);
 718                 if (racct_add(td->td_proc, RACCT_NSHM, 1)) {
 719                         PROC_UNLOCK(td->td_proc);
 720                         return (ENOSPC);
 721                 }
 722                 if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) {
 723                         racct_sub(td->td_proc, RACCT_NSHM, 1);
 724                         PROC_UNLOCK(td->td_proc);
 725                         return (ENOMEM);
 726                 }
 727                 PROC_UNLOCK(td->td_proc);
 728         }
 729 #endif
 730
 731         /*
 732          * We make sure that we have allocated a pager before we need
 733          * to.
 734          */
 735         shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP,
 736             0, size, VM_PROT_DEFAULT, 0, cred);
 737         if (shm_object == NULL) {
 738 #ifdef RACCT
 739                 if (racct_enable) {
 740                         PROC_LOCK(td->td_proc);
 741                         racct_sub(td->td_proc, RACCT_NSHM, 1);
 742                         racct_sub(td->td_proc, RACCT_SHMSIZE, size);
 743                         PROC_UNLOCK(td->td_proc);
 744                 }
 745 #endif
 746                 return (ENOMEM);
 747         }
 748         shm_object->pg_color = 0;
 749         VM_OBJECT_WLOCK(shm_object);
 750         vm_object_clear_flag(shm_object, OBJ_ONEMAPPING);
 751         vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT);
 752         VM_OBJECT_WUNLOCK(shm_object);
 753
 754         shmseg->object = shm_object;
 755         shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid;
 756         shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid;
 757         shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
 758         shmseg->u.shm_perm.key = uap->key;
 759         shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff;
 760         shmseg->cred = crhold(cred);
 761         shmseg->u.shm_segsz = uap->size;
 762         shmseg->u.shm_cpid = td->td_proc->p_pid;
 763         shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0;
 764         shmseg->u.shm_atime = shmseg->u.shm_dtime = 0;
 765 #ifdef MAC
 766         mac_sysvshm_create(cred, shmseg);
 767 #endif
 768         shmseg->u.shm_ctime = time_second;
 769         shm_committed += btoc(size);
 770         shm_nused++;
 771         td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm);
 772
 773         return (0);
 774 }
 775
 776 #ifndef _SYS_SYSPROTO_H_
 777 struct shmget_args {
 778         key_t key;
 779         size_t size;
 780         int shmflg;
 781 };
 782 #endif
 783 int
 784 sys_shmget(struct thread *td, struct shmget_args *uap)
 785 {
 786         int segnum, mode;
 787         int error;
 788
 789         if (shm_find_prison(td->td_ucred) == NULL)
 790                 return (ENOSYS);
 791         mode = uap->shmflg & ACCESSPERMS;
 792         SYSVSHM_LOCK();
 793         if (uap->key == IPC_PRIVATE) {
 794                 error = shmget_allocate_segment(td, uap, mode);
 795         } else {
 796                 segnum = shm_find_segment_by_key(td->td_ucred->cr_prison,
 797                     uap->key);
 798                 if (segnum >= 0)
 799                         error = shmget_existing(td, uap, mode, segnum);
 800                 else if ((uap->shmflg & IPC_CREAT) == 0)
 801                         error = ENOENT;
 802                 else
 803                         error = shmget_allocate_segment(td, uap, mode);
 804         }
 805         SYSVSHM_UNLOCK();
 806         return (error);
 807 }
 808
 809 static void
 810 shmfork_myhook(struct proc *p1, struct proc *p2)
 811 {
 812         struct shmmap_state *shmmap_s;
 813         size_t size;
 814         int i;
 815
 816         SYSVSHM_LOCK();
 817         size = shminfo.shmseg * sizeof(struct shmmap_state);
 818         shmmap_s = malloc(size, M_SHM, M_WAITOK);
 819         bcopy(p1->p_vmspace->vm_shm, shmmap_s, size);
 820         p2->p_vmspace->vm_shm = shmmap_s;
 821         for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
 822                 if (shmmap_s->shmid != -1) {
 823                         KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 &&
 824                             IPCID_TO_IX(shmmap_s->shmid) < shmalloced,
 825                             ("segnum %d shmalloced %d",
 826                             IPCID_TO_IX(shmmap_s->shmid), shmalloced));
 827                         shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++;
 828                 }
 829         }
 830         SYSVSHM_UNLOCK();
 831 }
 832
 833 static void
 834 shmexit_myhook(struct vmspace *vm)
 835 {
 836         struct shmmap_state *base, *shm;
 837         int i;
 838
 839         base = vm->vm_shm;
 840         if (base != NULL) {
 841                 vm->vm_shm = NULL;
 842                 SYSVSHM_LOCK();
 843                 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) {
 844                         if (shm->shmid != -1)
 845                                 shm_delete_mapping(vm, shm);
 846                 }
 847                 SYSVSHM_UNLOCK();
 848                 free(base, M_SHM);
 849         }
 850 }
 851
 852 static void
 853 shmrealloc(void)
 854 {
 855         struct shmid_kernel *newsegs;
 856         int i;
 857
 858         SYSVSHM_ASSERT_LOCKED();
 859
 860         if (shmalloced >= shminfo.shmmni)
 861                 return;
 862
 863         newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM,
 864             M_WAITOK | M_ZERO);
 865         for (i = 0; i < shmalloced; i++)
 866                 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
 867         for (; i < shminfo.shmmni; i++) {
 868                 newsegs[i].u.shm_perm.mode = SHMSEG_FREE;
 869                 newsegs[i].u.shm_perm.seq = 0;
 870 #ifdef MAC
 871                 mac_sysvshm_init(&newsegs[i]);
 872 #endif
 873         }
 874         free(shmsegs, M_SHM);
 875         shmsegs = newsegs;
 876         shmalloced = shminfo.shmmni;
 877 }
 878
 879 static struct syscall_helper_data shm_syscalls[] = {
 880         SYSCALL_INIT_HELPER(shmat),
 881         SYSCALL_INIT_HELPER(shmctl),
 882         SYSCALL_INIT_HELPER(shmdt),
 883         SYSCALL_INIT_HELPER(shmget),
 884 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 885     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 886         SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl),
 887 #endif
 888 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
 889         SYSCALL_INIT_HELPER(shmsys),
 890 #endif
 891         SYSCALL_INIT_LAST
 892 };
 893
 894 #ifdef COMPAT_FREEBSD32
 895 #include <compat/freebsd32/freebsd32.h>
 896 #include <compat/freebsd32/freebsd32_ipc.h>
 897 #include <compat/freebsd32/freebsd32_proto.h>
 898 #include <compat/freebsd32/freebsd32_signal.h>
 899 #include <compat/freebsd32/freebsd32_syscall.h>
 900 #include <compat/freebsd32/freebsd32_util.h>
 901
 902 static struct syscall_helper_data shm32_syscalls[] = {
 903         SYSCALL32_INIT_HELPER_COMPAT(shmat),
 904         SYSCALL32_INIT_HELPER_COMPAT(shmdt),
 905         SYSCALL32_INIT_HELPER_COMPAT(shmget),
 906         SYSCALL32_INIT_HELPER(freebsd32_shmsys),
 907         SYSCALL32_INIT_HELPER(freebsd32_shmctl),
 908 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
 909     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
 910         SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl),
 911 #endif
 912         SYSCALL_INIT_LAST
 913 };
 914 #endif
 915
 916 static int
 917 shminit(void)
 918 {
 919         struct prison *pr;
 920         void **rsv;
 921         int i, error;
 922         osd_method_t methods[PR_MAXMETHOD] = {
 923             [PR_METHOD_CHECK] =         shm_prison_check,
 924             [PR_METHOD_SET] =           shm_prison_set,
 925             [PR_METHOD_GET] =           shm_prison_get,
 926             [PR_METHOD_REMOVE] =        shm_prison_remove,
 927         };
 928
 929 #ifndef BURN_BRIDGES
 930         if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0)
 931                 printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n");
 932 #endif
 933         if (shminfo.shmmax == SHMMAX) {
 934                 /* Initialize shmmax dealing with possible overflow. */
 935                 for (i = PAGE_SIZE; i != 0; i--) {
 936                         shminfo.shmmax = shminfo.shmall * i;
 937                         if ((shminfo.shmmax / shminfo.shmall) == (u_long)i)
 938                                 break;
 939                 }
 940         }
 941         shmalloced = shminfo.shmmni;
 942         shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM,
 943             M_WAITOK|M_ZERO);
 944         for (i = 0; i < shmalloced; i++) {
 945                 shmsegs[i].u.shm_perm.mode = SHMSEG_FREE;
 946                 shmsegs[i].u.shm_perm.seq = 0;
 947 #ifdef MAC
 948                 mac_sysvshm_init(&shmsegs[i]);
 949 #endif
 950         }
 951         shm_last_free = 0;
 952         shm_nused = 0;
 953         shm_committed = 0;
 954         sx_init(&sysvshmsx, "sysvshmsx");
 955         shmexit_hook = &shmexit_myhook;
 956         shmfork_hook = &shmfork_myhook;
 957
 958         /* Set current prisons according to their allow.sysvipc. */
 959         shm_prison_slot = osd_jail_register(NULL, methods);
 960         rsv = osd_reserve(shm_prison_slot);
 961         prison_lock(&prison0);
 962         (void)osd_jail_set_reserved(&prison0, shm_prison_slot, rsv, &prison0);
 963         prison_unlock(&prison0);
 964         rsv = NULL;
 965         sx_slock(&allprison_lock);
 966         TAILQ_FOREACH(pr, &allprison, pr_list) {
 967                 if (rsv == NULL)
 968                         rsv = osd_reserve(shm_prison_slot);
 969                 prison_lock(pr);
 970                 if ((pr->pr_allow & PR_ALLOW_SYSVIPC) && pr->pr_ref > 0) {
 971                         (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
 972                             &prison0);
 973                         rsv = NULL;
 974                 }
 975                 prison_unlock(pr);
 976         }
 977         if (rsv != NULL)
 978                 osd_free_reserved(rsv);
 979         sx_sunlock(&allprison_lock);
 980
 981         error = syscall_helper_register(shm_syscalls, SY_THR_STATIC_KLD);
 982         if (error != 0)
 983                 return (error);
 984 #ifdef COMPAT_FREEBSD32
 985         error = syscall32_helper_register(shm32_syscalls, SY_THR_STATIC_KLD);
 986         if (error != 0)
 987                 return (error);
 988 #endif
 989         return (0);
 990 }
 991
 992 static int
 993 shmunload(void)
 994 {
 995         int i;
 996
 997         if (shm_nused > 0)
 998                 return (EBUSY);
 999
1000 #ifdef COMPAT_FREEBSD32
1001         syscall32_helper_unregister(shm32_syscalls);
1002 #endif
1003         syscall_helper_unregister(shm_syscalls);
1004         if (shm_prison_slot != 0)
1005                 osd_jail_deregister(shm_prison_slot);
1006
1007         for (i = 0; i < shmalloced; i++) {
1008 #ifdef MAC
1009                 mac_sysvshm_destroy(&shmsegs[i]);
1010 #endif
1011                 /*
1012                  * Objects might be still mapped into the processes
1013                  * address spaces.  Actual free would happen on the
1014                  * last mapping destruction.
1015                  */
1016                 if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE)
1017                         vm_object_deallocate(shmsegs[i].object);
1018         }
1019         free(shmsegs, M_SHM);
1020         shmexit_hook = NULL;
1021         shmfork_hook = NULL;
1022         sx_destroy(&sysvshmsx);
1023         return (0);
1024 }
1025
1026 static int
1027 sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
1028 {
1029         struct shmid_kernel tshmseg;
1030 #ifdef COMPAT_FREEBSD32
1031         struct shmid_kernel32 tshmseg32;
1032 #endif
1033         struct prison *pr, *rpr;
1034         void *outaddr;
1035         size_t outsize;
1036         int error, i;
1037
1038         SYSVSHM_LOCK();
1039         pr = req->td->td_ucred->cr_prison;
1040         rpr = shm_find_prison(req->td->td_ucred);
1041         error = 0;
1042         for (i = 0; i < shmalloced; i++) {
1043                 if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
1044                     rpr == NULL || shm_prison_cansee(rpr, &shmsegs[i]) != 0) {
1045                         bzero(&tshmseg, sizeof(tshmseg));
1046                         tshmseg.u.shm_perm.mode = SHMSEG_FREE;
1047                 } else {
1048                         tshmseg = shmsegs[i];
1049                         if (tshmseg.cred->cr_prison != pr)
1050                                 tshmseg.u.shm_perm.key = IPC_PRIVATE;
1051                 }
1052 #ifdef COMPAT_FREEBSD32
1053                 if (SV_CURPROC_FLAG(SV_ILP32)) {
1054                         bzero(&tshmseg32, sizeof(tshmseg32));
1055                         freebsd32_ipcperm_out(&tshmseg.u.shm_perm,
1056                             &tshmseg32.u.shm_perm);
1057                         CP(tshmseg, tshmseg32, u.shm_segsz);
1058                         CP(tshmseg, tshmseg32, u.shm_lpid);
1059                         CP(tshmseg, tshmseg32, u.shm_cpid);
1060                         CP(tshmseg, tshmseg32, u.shm_nattch);
1061                         CP(tshmseg, tshmseg32, u.shm_atime);
1062                         CP(tshmseg, tshmseg32, u.shm_dtime);
1063                         CP(tshmseg, tshmseg32, u.shm_ctime);
1064                         /* Don't copy object, label, or cred */
1065                         outaddr = &tshmseg32;
1066                         outsize = sizeof(tshmseg32);
1067                 } else
1068 #endif
1069                 {
1070                         tshmseg.object = NULL;
1071                         tshmseg.label = NULL;
1072                         tshmseg.cred = NULL;
1073                         outaddr = &tshmseg;
1074                         outsize = sizeof(tshmseg);
1075                 }
1076                 error = SYSCTL_OUT(req, outaddr, outsize);
1077                 if (error != 0)
1078                         break;
1079         }
1080         SYSVSHM_UNLOCK();
1081         return (error);
1082 }
1083
1084 static int
1085 shm_prison_check(void *obj, void *data)
1086 {
1087         struct prison *pr = obj;
1088         struct prison *prpr;
1089         struct vfsoptlist *opts = data;
1090         int error, jsys;
1091
1092         /*
1093          * sysvshm is a jailsys integer.
1094          * It must be "disable" if the parent jail is disabled.
1095          */
1096         error = vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys));
1097         if (error != ENOENT) {
1098                 if (error != 0)
1099                         return (error);
1100                 switch (jsys) {
1101                 case JAIL_SYS_DISABLE:
1102                         break;
1103                 case JAIL_SYS_NEW:
1104                 case JAIL_SYS_INHERIT:
1105                         prison_lock(pr->pr_parent);
1106                         prpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1107                         prison_unlock(pr->pr_parent);
1108                         if (prpr == NULL)
1109                                 return (EPERM);
1110                         break;
1111                 default:
1112                         return (EINVAL);
1113                 }
1114         }
1115
1116         return (0);
1117 }
1118
1119 static int
1120 shm_prison_set(void *obj, void *data)
1121 {
1122         struct prison *pr = obj;
1123         struct prison *tpr, *orpr, *nrpr, *trpr;
1124         struct vfsoptlist *opts = data;
1125         void *rsv;
1126         int jsys, descend;
1127
1128         /*
1129          * sysvshm controls which jail is the root of the associated segments
1130          * (this jail or same as the parent), or if the feature is available
1131          * at all.
1132          */
1133         if (vfs_copyopt(opts, "sysvshm", &jsys, sizeof(jsys)) == ENOENT)
1134                 jsys = vfs_flagopt(opts, "allow.sysvipc", NULL, 0)
1135                     ? JAIL_SYS_INHERIT
1136                     : vfs_flagopt(opts, "allow.nosysvipc", NULL, 0)
1137                     ? JAIL_SYS_DISABLE
1138                     : -1;
1139         if (jsys == JAIL_SYS_DISABLE) {
1140                 prison_lock(pr);
1141                 orpr = osd_jail_get(pr, shm_prison_slot);
1142                 if (orpr != NULL)
1143                         osd_jail_del(pr, shm_prison_slot);
1144                 prison_unlock(pr);
1145                 if (orpr != NULL) {
1146                         if (orpr == pr)
1147                                 shm_prison_cleanup(pr);
1148                         /* Disable all child jails as well. */
1149                         FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1150                                 prison_lock(tpr);
1151                                 trpr = osd_jail_get(tpr, shm_prison_slot);
1152                                 if (trpr != NULL) {
1153                                         osd_jail_del(tpr, shm_prison_slot);
1154                                         prison_unlock(tpr);
1155                                         if (trpr == tpr)
1156                                                 shm_prison_cleanup(tpr);
1157                                 } else {
1158                                         prison_unlock(tpr);
1159                                         descend = 0;
1160                                 }
1161                         }
1162                 }
1163         } else if (jsys != -1) {
1164                 if (jsys == JAIL_SYS_NEW)
1165                         nrpr = pr;
1166                 else {
1167                         prison_lock(pr->pr_parent);
1168                         nrpr = osd_jail_get(pr->pr_parent, shm_prison_slot);
1169                         prison_unlock(pr->pr_parent);
1170                 }
1171                 rsv = osd_reserve(shm_prison_slot);
1172                 prison_lock(pr);
1173                 orpr = osd_jail_get(pr, shm_prison_slot);
1174                 if (orpr != nrpr)
1175                         (void)osd_jail_set_reserved(pr, shm_prison_slot, rsv,
1176                             nrpr);
1177                 else
1178                         osd_free_reserved(rsv);
1179                 prison_unlock(pr);
1180                 if (orpr != nrpr) {
1181                         if (orpr == pr)
1182                                 shm_prison_cleanup(pr);
1183                         if (orpr != NULL) {
1184                                 /* Change child jails matching the old root, */
1185                                 FOREACH_PRISON_DESCENDANT(pr, tpr, descend) {
1186                                         prison_lock(tpr);
1187                                         trpr = osd_jail_get(tpr,
1188                                             shm_prison_slot);
1189                                         if (trpr == orpr) {
1190                                                 (void)osd_jail_set(tpr,
1191                                                     shm_prison_slot, nrpr);
1192                                                 prison_unlock(tpr);
1193                                                 if (trpr == tpr)
1194                                                         shm_prison_cleanup(tpr);
1195                                         } else {
1196                                                 prison_unlock(tpr);
1197                                                 descend = 0;
1198                                         }
1199                                 }
1200                         }
1201                 }
1202         }
1203
1204         return (0);
1205 }
1206
1207 static int
1208 shm_prison_get(void *obj, void *data)
1209 {
1210         struct prison *pr = obj;
1211         struct prison *rpr;
1212         struct vfsoptlist *opts = data;
1213         int error, jsys;
1214
1215         /* Set sysvshm based on the jail's root prison. */
1216         prison_lock(pr);
1217         rpr = osd_jail_get(pr, shm_prison_slot);
1218         prison_unlock(pr);
1219         jsys = rpr == NULL ? JAIL_SYS_DISABLE
1220             : rpr == pr ? JAIL_SYS_NEW : JAIL_SYS_INHERIT;
1221         error = vfs_setopt(opts, "sysvshm", &jsys, sizeof(jsys));
1222         if (error == ENOENT)
1223                 error = 0;
1224         return (error);
1225 }
1226
1227 static int
1228 shm_prison_remove(void *obj, void *data __unused)
1229 {
1230         struct prison *pr = obj;
1231         struct prison *rpr;
1232
1233         SYSVSHM_LOCK();
1234         prison_lock(pr);
1235         rpr = osd_jail_get(pr, shm_prison_slot);
1236         prison_unlock(pr);
1237         if (rpr == pr)
1238                 shm_prison_cleanup(pr);
1239         SYSVSHM_UNLOCK();
1240         return (0);
1241 }
1242
1243 static void
1244 shm_prison_cleanup(struct prison *pr)
1245 {
1246         struct shmid_kernel *shmseg;
1247         int i;
1248
1249         /* Remove any segments that belong to this jail. */
1250         for (i = 0; i < shmalloced; i++) {
1251                 shmseg = &shmsegs[i];
1252                 if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) &&
1253                     shmseg->cred != NULL && shmseg->cred->cr_prison == pr) {
1254                         shm_remove(shmseg, i);
1255                 }
1256         }
1257 }
1258
1259 SYSCTL_JAIL_PARAM_SYS_NODE(sysvshm, CTLFLAG_RW, "SYSV shared memory");
1260
1261 #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43))
1262 struct oshmid_ds {
1263         struct  ipc_perm_old shm_perm;  /* operation perms */
1264         int     shm_segsz;              /* size of segment (bytes) */
1265         u_short shm_cpid;               /* pid, creator */
1266         u_short shm_lpid;               /* pid, last operation */
1267         short   shm_nattch;             /* no. of current attaches */
1268         time_t  shm_atime;              /* last attach time */
1269         time_t  shm_dtime;              /* last detach time */
1270         time_t  shm_ctime;              /* last change time */
1271         void    *shm_handle;            /* internal handle for shm segment */
1272 };
1273
1274 struct oshmctl_args {
1275         int shmid;
1276         int cmd;
1277         struct oshmid_ds *ubuf;
1278 };
1279
1280 static int
1281 oshmctl(struct thread *td, struct oshmctl_args *uap)
1282 {
1283 #ifdef COMPAT_43
1284         int error = 0;
1285         struct prison *rpr;
1286         struct shmid_kernel *shmseg;
1287         struct oshmid_ds outbuf;
1288
1289         rpr = shm_find_prison(td->td_ucred);
1290         if (rpr == NULL)
1291                 return (ENOSYS);
1292         if (uap->cmd != IPC_STAT) {
1293                 return (freebsd7_shmctl(td,
1294                     (struct freebsd7_shmctl_args *)uap));
1295         }
1296         SYSVSHM_LOCK();
1297         shmseg = shm_find_segment(rpr, uap->shmid, true);
1298         if (shmseg == NULL) {
1299                 SYSVSHM_UNLOCK();
1300                 return (EINVAL);
1301         }
1302         error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
1303         if (error != 0) {
1304                 SYSVSHM_UNLOCK();
1305                 return (error);
1306         }
1307 #ifdef MAC
1308         error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd);
1309         if (error != 0) {
1310                 SYSVSHM_UNLOCK();
1311                 return (error);
1312         }
1313 #endif
1314         ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm);
1315         outbuf.shm_segsz = shmseg->u.shm_segsz;
1316         outbuf.shm_cpid = shmseg->u.shm_cpid;
1317         outbuf.shm_lpid = shmseg->u.shm_lpid;
1318         outbuf.shm_nattch = shmseg->u.shm_nattch;
1319         outbuf.shm_atime = shmseg->u.shm_atime;
1320         outbuf.shm_dtime = shmseg->u.shm_dtime;
1321         outbuf.shm_ctime = shmseg->u.shm_ctime;
1322         outbuf.shm_handle = shmseg->object;
1323         SYSVSHM_UNLOCK();
1324         return (copyout(&outbuf, uap->ubuf, sizeof(outbuf)));
1325 #else
1326         return (EINVAL);
1327 #endif
1328 }
1329
1330 /* XXX casting to (sy_call_t *) is bogus, as usual. */
1331 static sy_call_t *shmcalls[] = {
1332         (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl,
1333         (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget,
1334         (sy_call_t *)freebsd7_shmctl
1335 };
1336
1337 #ifndef _SYS_SYSPROTO_H_
1338 /* XXX actually varargs. */
1339 struct shmsys_args {
1340         int     which;
1341         int     a2;
1342         int     a3;
1343         int     a4;
1344 };
1345 #endif
1346 int
1347 sys_shmsys(struct thread *td, struct shmsys_args *uap)
1348 {
1349
1350         AUDIT_ARG_SVIPC_WHICH(uap->which);
1351         if (uap->which < 0 || uap->which >= nitems(shmcalls))
1352                 return (EINVAL);
1353         return ((*shmcalls[uap->which])(td, &uap->a2));
1354 }
1355
1356 #endif  /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */
1357
1358 #ifdef COMPAT_FREEBSD32
1359
1360 int
1361 freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap)
1362 {
1363
1364 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1365     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1366         AUDIT_ARG_SVIPC_WHICH(uap->which);
1367         switch (uap->which) {
1368         case 0: {       /* shmat */
1369                 struct shmat_args ap;
1370
1371                 ap.shmid = uap->a2;
1372                 ap.shmaddr = PTRIN(uap->a3);
1373                 ap.shmflg = uap->a4;
1374                 return (sysent[SYS_shmat].sy_call(td, &ap));
1375         }
1376         case 2: {       /* shmdt */
1377                 struct shmdt_args ap;
1378
1379                 ap.shmaddr = PTRIN(uap->a2);
1380                 return (sysent[SYS_shmdt].sy_call(td, &ap));
1381         }
1382         case 3: {       /* shmget */
1383                 struct shmget_args ap;
1384
1385                 ap.key = uap->a2;
1386                 ap.size = uap->a3;
1387                 ap.shmflg = uap->a4;
1388                 return (sysent[SYS_shmget].sy_call(td, &ap));
1389         }
1390         case 4: {       /* shmctl */
1391                 struct freebsd7_freebsd32_shmctl_args ap;
1392
1393                 ap.shmid = uap->a2;
1394                 ap.cmd = uap->a3;
1395                 ap.buf = PTRIN(uap->a4);
1396                 return (freebsd7_freebsd32_shmctl(td, &ap));
1397         }
1398         case 1:         /* oshmctl */
1399         default:
1400                 return (EINVAL);
1401         }
1402 #else
1403         return (nosys(td, NULL));
1404 #endif
1405 }
1406
1407 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1408     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1409 int
1410 freebsd7_freebsd32_shmctl(struct thread *td,
1411     struct freebsd7_freebsd32_shmctl_args *uap)
1412 {
1413         int error;
1414         union {
1415                 struct shmid_ds shmid_ds;
1416                 struct shm_info shm_info;
1417                 struct shminfo shminfo;
1418         } u;
1419         union {
1420                 struct shmid_ds32_old shmid_ds32;
1421                 struct shm_info32 shm_info32;
1422                 struct shminfo32 shminfo32;
1423         } u32;
1424         size_t sz;
1425
1426         if (uap->cmd == IPC_SET) {
1427                 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1428                     sizeof(u32.shmid_ds32))))
1429                         goto done;
1430                 freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm,
1431                     &u.shmid_ds.shm_perm);
1432                 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1433                 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1434                 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1435                 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1436                 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1437                 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1438                 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1439         }
1440
1441         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1442         if (error)
1443                 goto done;
1444
1445         /* Cases in which we need to copyout */
1446         switch (uap->cmd) {
1447         case IPC_INFO:
1448                 CP(u.shminfo, u32.shminfo32, shmmax);
1449                 CP(u.shminfo, u32.shminfo32, shmmin);
1450                 CP(u.shminfo, u32.shminfo32, shmmni);
1451                 CP(u.shminfo, u32.shminfo32, shmseg);
1452                 CP(u.shminfo, u32.shminfo32, shmall);
1453                 error = copyout(&u32.shminfo32, uap->buf,
1454                     sizeof(u32.shminfo32));
1455                 break;
1456         case SHM_INFO:
1457                 CP(u.shm_info, u32.shm_info32, used_ids);
1458                 CP(u.shm_info, u32.shm_info32, shm_rss);
1459                 CP(u.shm_info, u32.shm_info32, shm_tot);
1460                 CP(u.shm_info, u32.shm_info32, shm_swp);
1461                 CP(u.shm_info, u32.shm_info32, swap_attempts);
1462                 CP(u.shm_info, u32.shm_info32, swap_successes);
1463                 error = copyout(&u32.shm_info32, uap->buf,
1464                     sizeof(u32.shm_info32));
1465                 break;
1466         case SHM_STAT:
1467         case IPC_STAT:
1468                 memset(&u32.shmid_ds32, 0, sizeof(u32.shmid_ds32));
1469                 freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm,
1470                     &u32.shmid_ds32.shm_perm);
1471                 if (u.shmid_ds.shm_segsz > INT32_MAX)
1472                         u32.shmid_ds32.shm_segsz = INT32_MAX;
1473                 else
1474                         CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1475                 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1476                 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1477                 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1478                 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1479                 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1480                 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1481                 u32.shmid_ds32.shm_internal = 0;
1482                 error = copyout(&u32.shmid_ds32, uap->buf,
1483                     sizeof(u32.shmid_ds32));
1484                 break;
1485         }
1486
1487 done:
1488         if (error) {
1489                 /* Invalidate the return value */
1490                 td->td_retval[0] = -1;
1491         }
1492         return (error);
1493 }
1494 #endif
1495
1496 int
1497 freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap)
1498 {
1499         int error;
1500         union {
1501                 struct shmid_ds shmid_ds;
1502                 struct shm_info shm_info;
1503                 struct shminfo shminfo;
1504         } u;
1505         union {
1506                 struct shmid_ds32 shmid_ds32;
1507                 struct shm_info32 shm_info32;
1508                 struct shminfo32 shminfo32;
1509         } u32;
1510         size_t sz;
1511
1512         if (uap->cmd == IPC_SET) {
1513                 if ((error = copyin(uap->buf, &u32.shmid_ds32,
1514                     sizeof(u32.shmid_ds32))))
1515                         goto done;
1516                 freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm,
1517                     &u.shmid_ds.shm_perm);
1518                 CP(u32.shmid_ds32, u.shmid_ds, shm_segsz);
1519                 CP(u32.shmid_ds32, u.shmid_ds, shm_lpid);
1520                 CP(u32.shmid_ds32, u.shmid_ds, shm_cpid);
1521                 CP(u32.shmid_ds32, u.shmid_ds, shm_nattch);
1522                 CP(u32.shmid_ds32, u.shmid_ds, shm_atime);
1523                 CP(u32.shmid_ds32, u.shmid_ds, shm_dtime);
1524                 CP(u32.shmid_ds32, u.shmid_ds, shm_ctime);
1525         }
1526
1527         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz);
1528         if (error)
1529                 goto done;
1530
1531         /* Cases in which we need to copyout */
1532         switch (uap->cmd) {
1533         case IPC_INFO:
1534                 CP(u.shminfo, u32.shminfo32, shmmax);
1535                 CP(u.shminfo, u32.shminfo32, shmmin);
1536                 CP(u.shminfo, u32.shminfo32, shmmni);
1537                 CP(u.shminfo, u32.shminfo32, shmseg);
1538                 CP(u.shminfo, u32.shminfo32, shmall);
1539                 error = copyout(&u32.shminfo32, uap->buf,
1540                     sizeof(u32.shminfo32));
1541                 break;
1542         case SHM_INFO:
1543                 CP(u.shm_info, u32.shm_info32, used_ids);
1544                 CP(u.shm_info, u32.shm_info32, shm_rss);
1545                 CP(u.shm_info, u32.shm_info32, shm_tot);
1546                 CP(u.shm_info, u32.shm_info32, shm_swp);
1547                 CP(u.shm_info, u32.shm_info32, swap_attempts);
1548                 CP(u.shm_info, u32.shm_info32, swap_successes);
1549                 error = copyout(&u32.shm_info32, uap->buf,
1550                     sizeof(u32.shm_info32));
1551                 break;
1552         case SHM_STAT:
1553         case IPC_STAT:
1554                 freebsd32_ipcperm_out(&u.shmid_ds.shm_perm,
1555                     &u32.shmid_ds32.shm_perm);
1556                 if (u.shmid_ds.shm_segsz > INT32_MAX)
1557                         u32.shmid_ds32.shm_segsz = INT32_MAX;
1558                 else
1559                         CP(u.shmid_ds, u32.shmid_ds32, shm_segsz);
1560                 CP(u.shmid_ds, u32.shmid_ds32, shm_lpid);
1561                 CP(u.shmid_ds, u32.shmid_ds32, shm_cpid);
1562                 CP(u.shmid_ds, u32.shmid_ds32, shm_nattch);
1563                 CP(u.shmid_ds, u32.shmid_ds32, shm_atime);
1564                 CP(u.shmid_ds, u32.shmid_ds32, shm_dtime);
1565                 CP(u.shmid_ds, u32.shmid_ds32, shm_ctime);
1566                 error = copyout(&u32.shmid_ds32, uap->buf,
1567                     sizeof(u32.shmid_ds32));
1568                 break;
1569         }
1570
1571 done:
1572         if (error) {
1573                 /* Invalidate the return value */
1574                 td->td_retval[0] = -1;
1575         }
1576         return (error);
1577 }
1578 #endif
1579
1580 #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
1581     defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
1582
1583 #ifndef CP
1584 #define CP(src, dst, fld)       do { (dst).fld = (src).fld; } while (0)
1585 #endif
1586
1587 #ifndef _SYS_SYSPROTO_H_
1588 struct freebsd7_shmctl_args {
1589         int shmid;
1590         int cmd;
1591         struct shmid_ds_old *buf;
1592 };
1593 #endif
1594 int
1595 freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap)
1596 {
1597         int error;
1598         struct shmid_ds_old old;
1599         struct shmid_ds buf;
1600         size_t bufsz;
1601
1602         /*
1603          * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support
1604          * Linux binaries.  If we see the call come through the FreeBSD ABI,
1605          * return an error back to the user since we do not to support this.
1606          */
1607         if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO ||
1608             uap->cmd == SHM_STAT)
1609                 return (EINVAL);
1610
1611         /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
1612         if (uap->cmd == IPC_SET) {
1613                 if ((error = copyin(uap->buf, &old, sizeof(old))))
1614                         goto done;
1615                 ipcperm_old2new(&old.shm_perm, &buf.shm_perm);
1616                 CP(old, buf, shm_segsz);
1617                 CP(old, buf, shm_lpid);
1618                 CP(old, buf, shm_cpid);
1619                 CP(old, buf, shm_nattch);
1620                 CP(old, buf, shm_atime);
1621                 CP(old, buf, shm_dtime);
1622                 CP(old, buf, shm_ctime);
1623         }
1624
1625         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
1626         if (error)
1627                 goto done;
1628
1629         /* Cases in which we need to copyout */
1630         switch (uap->cmd) {
1631         case IPC_STAT:
1632                 memset(&old, 0, sizeof(old));
1633                 ipcperm_new2old(&buf.shm_perm, &old.shm_perm);
1634                 if (buf.shm_segsz > INT_MAX)
1635                         old.shm_segsz = INT_MAX;
1636                 else
1637                         CP(buf, old, shm_segsz);
1638                 CP(buf, old, shm_lpid);
1639                 CP(buf, old, shm_cpid);
1640                 if (buf.shm_nattch > SHRT_MAX)
1641                         old.shm_nattch = SHRT_MAX;
1642                 else
1643                         CP(buf, old, shm_nattch);
1644                 CP(buf, old, shm_atime);
1645                 CP(buf, old, shm_dtime);
1646                 CP(buf, old, shm_ctime);
1647                 old.shm_internal = NULL;
1648                 error = copyout(&old, uap->buf, sizeof(old));
1649                 break;
1650         }
1651
1652 done:
1653         if (error) {
1654                 /* Invalidate the return value */
1655                 td->td_retval[0] = -1;
1656         }
1657         return (error);
1658 }
1659
1660 #endif  /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 ||
1661            COMPAT_FREEBSD7 */
1662
1663 static int
1664 sysvshm_modload(struct module *module, int cmd, void *arg)
1665 {
1666         int error = 0;
1667
1668         switch (cmd) {
1669         case MOD_LOAD:
1670                 error = shminit();
1671                 if (error != 0)
1672                         shmunload();
1673                 break;
1674         case MOD_UNLOAD:
1675                 error = shmunload();
1676                 break;
1677         case MOD_SHUTDOWN:
1678                 break;
1679         default:
1680                 error = EINVAL;
1681                 break;
1682         }
1683         return (error);
1684 }
1685
1686 static moduledata_t sysvshm_mod = {
1687         "sysvshm",
1688         &sysvshm_modload,
1689         NULL
1690 };
1691
1692 DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
1693 MODULE_VERSION(sysvshm, 1);