winsup/cygserver/sysv_shm.cc

   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 /*
  33  * This file is heavily changed to become part of Cygwin's cygserver.
  34  */
  35
  36 #ifdef __OUTSIDE_CYGWIN__
  37 #include "woutsup.h"
  38 #include <sys/cdefs.h>
  39 #ifndef __FBSDID
  40 #define __FBSDID(s)     const char version[] = (s)
  41 #endif
  42 __FBSDID("$FreeBSD: /repoman/r/ncvs/src/sys/kern/sysv_shm.c,v 1.89 2003/11/07 04:47:14 rwatson Exp $");
  43
  44 #define _KERNEL 1
  45 #define __BSD_VISIBLE 1
  46 #include <sys/param.h>
  47 #include <sys/lock.h>
  48 #include <sys/shm.h>
  49 #include <malloc.h>
  50 #include <sys/mman.h>
  51 #include <sys/stat.h>
  52 #include <sys/sysproto.h>
  53
  54 #include <errno.h>
  55 #include <time.h>
  56 #include <unistd.h>
  57 #include "cygserver.h"
  58 #include "process.h"
  59 #include "cygserver_ipc.h"
  60
  61 #ifdef __CYGWIN__
  62 #ifndef PAGE_SIZE
  63 #define PAGE_SIZE (getpagesize ())
  64 #endif
  65 #ifndef PAGE_MASK
  66 #define PAGE_MASK (PAGE_SIZE - 1)
  67 #endif
  68 #define btoc(b) (((b) + PAGE_MASK) / PAGE_SIZE)
  69 #define round_page(p) ((((unsigned long)(p)) + PAGE_MASK) & ~(PAGE_MASK))
  70 #define ACCESSPERMS (0777)
  71 #define GIANT_REQUIRED mtx_assert(&Giant, MA_OWNED)
  72 #define KERN_SUCCESS 0
  73 #define VM_PROT_READ    PROT_READ
  74 #define VM_PROT_WRITE   PROT_WRITE
  75 #define VM_INHERIT_SHARE 0
  76 #define OBJT_PHYS  0
  77 #define OBJT_SWAP  0
  78 #define VM_PROT_DEFAULT 0
  79 #define VM_OBJECT_LOCK(a)
  80 #define vm_object_clear_flag(a,b)
  81 #define vm_object_set_flag(a,b)
  82 #define VM_OBJECT_UNLOCK(a)
  83 #define vm_object_reference(a)
  84 #define vm_map_remove(a,b,c) KERN_SUCCESS
  85 #define vm_map_find(a,b,c,d,e,f,g,h,i) KERN_SUCCESS
  86 #define vm_map_inherit(a,b,c,d)
  87 typedef int vm_prot_t;
  88 #endif /* __CYGWIN__ */
  89
  90 #ifndef __CYGWIN__
  91 static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
  92
  93 struct oshmctl_args;
  94 static int oshmctl(struct thread *td, struct oshmctl_args *uap);
  95 #endif /* __CYGWIN__ */
  96
  97 static int shmget_allocate_segment(struct thread *td,
  98     struct shmget_args *uap, int mode);
  99 static int shmget_existing(struct thread *td, struct shmget_args *uap,
 100     int mode, int segnum);
 101
 102 #ifndef __CYGWIN__
 103 /* XXX casting to (sy_call_t *) is bogus, as usual. */
 104 static sy_call_t *shmcalls[] = {
 105         (sy_call_t *)shmat, (sy_call_t *)oshmctl,
 106         (sy_call_t *)shmdt, (sy_call_t *)shmget,
 107         (sy_call_t *)shmctl
 108 };
 109 #endif /* __CYGWIN__ */
 110
 111 #define SHMSEG_FREE             0x0200
 112 #define SHMSEG_REMOVED          0x0400
 113 #define SHMSEG_ALLOCATED        0x0800
 114 #define SHMSEG_WANTED           0x1000
 115
 116 static int shm_last_free, shm_nused, shm_committed, shmalloced, shm_nattch;
 117 static struct shmid_ds  *shmsegs;
 118
 119 struct shm_handle {
 120         /* vm_offset_t kva; */
 121         vm_object_t shm_object;
 122 };
 123
 124 struct shmmap_state {
 125         vm_offset_t va;
 126         int shmid;
 127 };
 128
 129 static void shm_deallocate_segment(struct shmid_ds *);
 130 static int shm_find_segment_by_key(key_t);
 131 static struct shmid_ds *shm_find_segment_by_shmid(int);
 132 static struct shmid_ds *shm_find_segment_by_shmidx(int);
 133 static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *);
 134 static void shmrealloc(void);
 135
 136 /*
 137  * Tuneable values.
 138  */
 139 #ifndef SHMMAXPGS
 140 #define SHMMAXPGS       8192    /* Note: sysv shared memory is swap backed. */
 141 #endif
 142 #ifndef SHMMAX
 143 #define SHMMAX  (SHMMAXPGS*PAGE_SIZE)
 144 #endif
 145 #ifndef SHMMIN
 146 #define SHMMIN  1
 147 #endif
 148 #ifndef SHMMNI
 149 #define SHMMNI  192
 150 #endif
 151 #ifndef SHMSEG
 152 #define SHMSEG  128
 153 #endif
 154 #ifndef SHMALL
 155 #define SHMALL  (SHMMAXPGS)
 156 #endif
 157
 158 struct  shminfo shminfo = {
 159         SHMMAX,
 160         SHMMIN,
 161         SHMMNI,
 162         SHMSEG,
 163         SHMALL
 164 };
 165
 166 #ifndef __CYGWIN__
 167 static int shm_use_phys;
 168 #else
 169 static long shm_use_phys;
 170 static long shm_allow_removed;
 171 #endif /* __CYGWIN__ */
 172
 173 #ifndef __CYGWIN__
 174 struct shm_info shm_info;
 175 #endif /* __CYGWIN__ */
 176
 177 #ifndef __CYGWIN__
 178 SYSCTL_DECL(_kern_ipc);
 179 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0, "");
 180 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0, "");
 181 SYSCTL_INT(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0, "");
 182 SYSCTL_INT(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0, "");
 183 SYSCTL_INT(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0, "");
 184 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW,
 185     &shm_use_phys, 0, "");
 186 SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RW,
 187     &shm_allow_removed, 0, "");
 188 SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLFLAG_RD,
 189     NULL, 0, sysctl_shmsegs, "", "");
 190 #endif /* __CYGWIN__ */
 191
 192 static int
 193 shm_find_segment_by_key(key_t key)
 194 {
 195         int i;
 196
 197         for (i = 0; i < shmalloced; i++)
 198                 if ((shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED) &&
 199                     shmsegs[i].shm_perm.key == key)
 200                         return (i);
 201         return (-1);
 202 }
 203
 204 static struct shmid_ds *
 205 shm_find_segment_by_shmid(int shmid)
 206 {
 207         int segnum;
 208         struct shmid_ds *shmseg;
 209
 210         segnum = IPCID_TO_IX(shmid);
 211         if (segnum < 0 || segnum >= shmalloced)
 212                 return (NULL);
 213         shmseg = &shmsegs[segnum];
 214         if ((shmseg->shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
 215             (!shm_allow_removed &&
 216              (shmseg->shm_perm.mode & SHMSEG_REMOVED) != 0) ||
 217             shmseg->shm_perm.seq != IPCID_TO_SEQ(shmid))
 218                 return (NULL);
 219         return (shmseg);
 220 }
 221
 222 static struct shmid_ds *
 223 shm_find_segment_by_shmidx(int segnum)
 224 {
 225         struct shmid_ds *shmseg;
 226
 227         if (segnum < 0 || segnum >= shmalloced)
 228                 return (NULL);
 229         shmseg = &shmsegs[segnum];
 230         if ((shmseg->shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
 231             (!shm_allow_removed &&
 232              (shmseg->shm_perm.mode & SHMSEG_REMOVED) != 0))
 233                 return (NULL);
 234         return (shmseg);
 235 }
 236
 237 static void
 238 shm_deallocate_segment(struct shmid_ds *shmseg)
 239 {
 240         struct shm_handle *shm_handle;
 241         size_t size;
 242
 243         GIANT_REQUIRED;
 244
 245         shm_handle = shmseg->shm_internal;
 246         vm_object_deallocate(shm_handle->shm_object);
 247         sys_free(shm_handle, M_SHM);
 248         shmseg->shm_internal = NULL;
 249         size = round_page(shmseg->shm_segsz);
 250         shm_committed -= btoc(size);
 251         shm_nused--;
 252         shmseg->shm_perm.mode = SHMSEG_FREE;
 253 }
 254
 255 static int
 256 shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s)
 257 {
 258         struct shmid_ds *shmseg;
 259         int segnum, result;
 260         size_t size;
 261
 262         GIANT_REQUIRED;
 263
 264         segnum = IPCID_TO_IX(shmmap_s->shmid);
 265         shmseg = &shmsegs[segnum];
 266         size = round_page(shmseg->shm_segsz);
 267         result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size);
 268         if (result != KERN_SUCCESS)
 269                 return (EINVAL);
 270         shmmap_s->shmid = -1;
 271         shmseg->shm_dtime = time (NULL);
 272         --shm_nattch;
 273         if ((--shmseg->shm_nattch <= 0) &&
 274             (shmseg->shm_perm.mode & SHMSEG_REMOVED)) {
 275                 shm_deallocate_segment(shmseg);
 276                 shm_last_free = segnum;
 277         }
 278         return (0);
 279 }
 280
 281 #ifndef _SYS_SYSPROTO_H_
 282 struct shmdt_args {
 283         const void *shmaddr;
 284 };
 285 #endif
 286
 287 /*
 288  * MPSAFE
 289  */
 290 int
 291 shmdt(struct thread *td, struct shmdt_args *uap)
 292 {
 293         struct proc *p = td->td_proc;
 294         struct shmmap_state *shmmap_s;
 295         int i;
 296         int error = 0;
 297
 298         if (!jail_sysvipc_allowed && jailed(td->td_ucred))
 299                 return (ENOSYS);
 300         mtx_lock(&Giant);
 301         shmmap_s = p->p_vmspace->vm_shm;
 302         if (shmmap_s == NULL) {
 303                 error = EINVAL;
 304                 goto done2;
 305         }
 306         for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
 307                 if (shmmap_s->shmid != -1 &&
 308                     shmmap_s->va == (vm_offset_t)uap->shmaddr) {
 309                         break;
 310                 }
 311         }
 312         if (i == shminfo.shmseg) {
 313                 error = EINVAL;
 314                 goto done2;
 315         }
 316         error = shm_delete_mapping(p->p_vmspace, shmmap_s);
 317 done2:
 318         mtx_unlock(&Giant);
 319         return (error);
 320 }
 321
 322 #ifndef _SYS_SYSPROTO_H_
 323 struct shmat_args {
 324         int shmid;
 325         const void *shmaddr;
 326         int shmflg;
 327 };
 328 #endif
 329
 330 /*
 331  * MPSAFE
 332  */
 333 int
 334 kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg)
 335 {
 336         struct proc *p = td->td_proc;
 337         int i, flags;
 338         struct shmid_ds *shmseg;
 339         struct shmmap_state *shmmap_s = NULL;
 340         struct shm_handle *shm_handle;
 341         vm_offset_t attach_va;
 342         vm_prot_t prot;
 343         vm_size_t size;
 344         int rv;
 345         int error = 0;
 346
 347         if (!jail_sysvipc_allowed && jailed(td->td_ucred))
 348                 return (ENOSYS);
 349         mtx_lock(&Giant);
 350         shmmap_s = p->p_vmspace->vm_shm;
 351         if (shmmap_s == NULL) {
 352                 size = shminfo.shmseg * sizeof(struct shmmap_state);
 353                 shmmap_s = (struct shmmap_state *) sys_malloc(size, M_SHM, M_WAITOK);
 354                 for (i = 0; i < shminfo.shmseg; i++)
 355                         shmmap_s[i].shmid = -1;
 356                 p->p_vmspace->vm_shm = shmmap_s;
 357         }
 358         shmseg = shm_find_segment_by_shmid(shmid);
 359         if (shmseg == NULL) {
 360                 error = EINVAL;
 361                 goto done2;
 362         }
 363         error = ipcperm(td, &shmseg->shm_perm,
 364             (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
 365         if (error)
 366                 goto done2;
 367         for (i = 0; i < shminfo.shmseg; i++) {
 368                 if (shmmap_s->shmid == -1)
 369                         break;
 370                 shmmap_s++;
 371         }
 372         if (i >= shminfo.shmseg) {
 373                 error = EMFILE;
 374                 goto done2;
 375         }
 376         size = round_page(shmseg->shm_segsz);
 377 #ifdef VM_PROT_READ_IS_EXEC
 378         prot = VM_PROT_READ | VM_PROT_EXECUTE;
 379 #else
 380         prot = VM_PROT_READ;
 381 #endif
 382         if ((shmflg & SHM_RDONLY) == 0)
 383                 prot |= VM_PROT_WRITE;
 384         flags = MAP_ANON | MAP_SHARED;
 385         if (shmaddr) {
 386                 flags |= MAP_FIXED;
 387                 if (shmflg & SHM_RND) {
 388                         attach_va = (vm_offset_t)shmaddr & ~(SHMLBA-1);
 389                 } else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0) {
 390                         attach_va = (vm_offset_t)shmaddr;
 391                 } else {
 392                         error = EINVAL;
 393                         goto done2;
 394                 }
 395         } else {
 396                 /*
 397                  * This is just a hint to vm_map_find() about where to
 398                  * put it.
 399                  */
 400 #ifdef __CYGWIN__
 401                 attach_va = 0;
 402 #else
 403                 attach_va = round_page((vm_offset_t)p->p_vmspace->vm_taddr
 404                     + maxtsiz + maxdsiz);
 405 #endif
 406         }
 407
 408         shm_handle = shmseg->shm_internal;
 409         vm_object_reference(shm_handle->shm_object);
 410         rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object,
 411                 0, &attach_va, size, (flags & MAP_FIXED)?0:1, prot, prot, 0);
 412         if (rv != KERN_SUCCESS) {
 413                 error = ENOMEM;
 414                 goto done2;
 415         }
 416         vm_map_inherit(&p->p_vmspace->vm_map,
 417                 attach_va, attach_va + size, VM_INHERIT_SHARE);
 418
 419         shmmap_s->va = attach_va;
 420         shmmap_s->shmid = shmid;
 421         shmseg->shm_lpid = p->p_pid;
 422         shmseg->shm_atime = time (NULL);
 423         shmseg->shm_nattch++;
 424         shm_nattch++;
 425         td->td_retval[0] = attach_va;
 426 done2:
 427         mtx_unlock(&Giant);
 428         return (error);
 429 }
 430
 431 int
 432 shmat(struct thread *td, struct shmat_args *uap)
 433 {
 434         return kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg);
 435 }
 436
 437 #ifndef __CYGWIN__
 438 struct oshmid_ds {
 439         struct  ipc_perm shm_perm;      /* operation perms */
 440         int     shm_segsz;              /* size of segment (bytes) */
 441         u_short shm_cpid;               /* pid, creator */
 442         u_short shm_lpid;               /* pid, last operation */
 443         short   shm_nattch;             /* no. of current attaches */
 444         time_t  shm_atime;              /* last attach time */
 445         time_t  shm_dtime;              /* last detach time */
 446         time_t  shm_ctime;              /* last change time */
 447         void    *shm_handle;            /* internal handle for shm segment */
 448 };
 449
 450 struct oshmctl_args {
 451         int shmid;
 452         int cmd;
 453         struct oshmid_ds *ubuf;
 454 };
 455
 456 /*
 457  * MPSAFE
 458  */
 459 static int
 460 oshmctl(struct thread *td, struct oshmctl_args *uap)
 461 {
 462 #ifdef COMPAT_43
 463         int error = 0;
 464         struct shmid_ds *shmseg;
 465         struct oshmid_ds outbuf;
 466
 467         if (!jail_sysvipc_allowed && jailed(td->td_ucred))
 468                 return (ENOSYS);
 469         mtx_lock(&Giant);
 470         shmseg = shm_find_segment_by_shmid(uap->shmid);
 471         if (shmseg == NULL) {
 472                 error = EINVAL;
 473                 goto done2;
 474         }
 475         switch (uap->cmd) {
 476         case IPC_STAT:
 477                 error = ipcperm(td, &shmseg->shm_perm, IPC_R);
 478                 if (error)
 479                         goto done2;
 480                 outbuf.shm_perm = shmseg->shm_perm;
 481                 outbuf.shm_segsz = shmseg->shm_segsz;
 482                 outbuf.shm_cpid = shmseg->shm_cpid;
 483                 outbuf.shm_lpid = shmseg->shm_lpid;
 484                 outbuf.shm_nattch = shmseg->shm_nattch;
 485                 outbuf.shm_atime = shmseg->shm_atime;
 486                 outbuf.shm_dtime = shmseg->shm_dtime;
 487                 outbuf.shm_ctime = shmseg->shm_ctime;
 488                 outbuf.shm_handle = shmseg->shm_internal;
 489                 error = copyout(&outbuf, uap->ubuf, sizeof(outbuf));
 490                 if (error)
 491                         goto done2;
 492                 break;
 493         default:
 494                 /* XXX casting to (sy_call_t *) is bogus, as usual. */
 495                 error = ((sy_call_t *)shmctl)(td, uap);
 496                 break;
 497         }
 498 done2:
 499         mtx_unlock(&Giant);
 500         return (error);
 501 #else
 502         return (EINVAL);
 503 #endif
 504 }
 505 #endif /* __CYGWIN__ */
 506
 507 #ifndef _SYS_SYSPROTO_H_
 508 struct shmctl_args {
 509         int shmid;
 510         int cmd;
 511         struct shmid_ds *buf;
 512 };
 513 #endif
 514
 515 /*
 516  * MPSAFE
 517  */
 518 int
 519 kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz)
 520 {
 521         int error = 0;
 522         struct shmid_ds *shmseg;
 523
 524         if (!jail_sysvipc_allowed && jailed(td->td_ucred))
 525                 return (ENOSYS);
 526
 527         mtx_lock(&Giant);
 528         switch (cmd) {
 529         case IPC_INFO:
 530                 memcpy(buf, &shminfo, sizeof(shminfo));
 531                 if (bufsz)
 532                         *bufsz = sizeof(shminfo);
 533                 td->td_retval[0] = shmalloced;
 534                 goto done2;
 535         case SHM_INFO: {
 536                 struct shm_info shm_info;
 537                 shm_info.used_ids = shm_nused;
 538                 shm_info.shm_tot = shm_committed * PAGE_SIZE;
 539 #ifdef __CYGWIN__
 540                 shm_info.shm_atts = shm_nattch;
 541 #else
 542                 shm_info.shm_rss = 0;   /*XXX where to get from ? */
 543                 shm_info.shm_swp = 0;   /*XXX where to get from ? */
 544                 shm_info.swap_attempts = 0;     /*XXX where to get from ? */
 545                 shm_info.swap_successes = 0;    /*XXX where to get from ? */
 546 #endif /* __CYGWIN__ */
 547                 memcpy(buf, &shm_info, sizeof(shm_info));
 548                 if (bufsz)
 549                         *bufsz = sizeof(shm_info);
 550                 td->td_retval[0] = shmalloced;
 551                 goto done2;
 552         }
 553         }
 554         if (cmd == SHM_STAT)
 555                 shmseg = shm_find_segment_by_shmidx(shmid);
 556         else
 557                 shmseg = shm_find_segment_by_shmid(shmid);
 558         if (shmseg == NULL) {
 559                 error = EINVAL;
 560                 goto done2;
 561         }
 562         switch (cmd) {
 563         case SHM_STAT:
 564         case IPC_STAT:
 565                 error = ipcperm(td, &shmseg->shm_perm, IPC_R);
 566                 if (error)
 567                         goto done2;
 568                 memcpy(buf, shmseg, sizeof(struct shmid_ds));
 569                 if (bufsz)
 570                         *bufsz = sizeof(struct shmid_ds);
 571                 if (cmd == SHM_STAT)
 572                         td->td_retval[0] = IXSEQ_TO_IPCID(shmid, shmseg->shm_perm);
 573                 break;
 574         case IPC_SET: {
 575                 struct shmid_ds *shmid;
 576
 577                 shmid = (struct shmid_ds *)buf;
 578                 error = ipcperm(td, &shmseg->shm_perm, IPC_M);
 579                 if (error)
 580                         goto done2;
 581                 shmseg->shm_perm.uid = shmid->shm_perm.uid;
 582                 shmseg->shm_perm.gid = shmid->shm_perm.gid;
 583                 shmseg->shm_perm.mode =
 584                     (shmseg->shm_perm.mode & ~ACCESSPERMS) |
 585                     (shmid->shm_perm.mode & ACCESSPERMS);
 586                 shmseg->shm_ctime = time (NULL);
 587                 break;
 588         }
 589         case IPC_RMID:
 590                 error = ipcperm(td, &shmseg->shm_perm, IPC_M);
 591                 if (error)
 592                         goto done2;
 593                 shmseg->shm_perm.key = IPC_PRIVATE;
 594                 shmseg->shm_perm.mode |= SHMSEG_REMOVED;
 595                 if (shmseg->shm_nattch <= 0) {
 596                         shm_deallocate_segment(shmseg);
 597                         shm_last_free = IPCID_TO_IX(shmid);
 598                 }
 599                 break;
 600 #if 0
 601         case SHM_LOCK:
 602         case SHM_UNLOCK:
 603 #endif
 604         default:
 605                 error = EINVAL;
 606                 break;
 607         }
 608 done2:
 609         mtx_unlock(&Giant);
 610         return (error);
 611 }
 612
 613 int
 614 shmctl(struct thread *td, struct shmctl_args *uap)
 615 {
 616         int error = 0;
 617         struct shmid_ds buf;
 618         size_t bufsz;
 619
 620         /* IPC_SET needs to copyin the buffer before calling kern_shmctl */
 621         if (uap->cmd == IPC_SET) {
 622                 if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds))))
 623                         goto done;
 624         }
 625 #ifdef __CYGWIN__
 626         if (uap->cmd == IPC_INFO && uap->shmid > 0) {
 627                 /* Can't use the default kern_shmctl interface. */
 628                 int shmid = uap->shmid;
 629                 if (shmid > shminfo.shmmni)
 630                         shmid = shminfo.shmmni;
 631                 error = copyout(shmsegs, uap->buf,
 632                                 shmid * sizeof(struct shmid_ds));
 633                 td->td_retval[0] = error ? -1 : 0;
 634                 return (error);
 635         }
 636 #endif /* __CYGWIN__ */
 637
 638         error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz);
 639         if (error)
 640                 goto done;
 641
 642         /* Cases in which we need to copyout */
 643         switch (uap->cmd) {
 644         case IPC_INFO:
 645         case SHM_INFO:
 646         case SHM_STAT:
 647         case IPC_STAT:
 648                 error = copyout(&buf, uap->buf, bufsz);
 649                 break;
 650         }
 651
 652 done:
 653         if (error) {
 654                 /* Invalidate the return value */
 655                 td->td_retval[0] = -1;
 656         }
 657         return (error);
 658 }
 659
 660
 661 #ifndef _SYS_SYSPROTO_H_
 662 struct shmget_args {
 663         key_t key;
 664         size_t size;
 665         int shmflg;
 666 };
 667 #endif
 668
 669 static int
 670 shmget_existing(struct thread *td, struct shmget_args *uap, int mode, int segnum)
 671 {
 672         struct shmid_ds *shmseg;
 673         int error;
 674
 675         shmseg = &shmsegs[segnum];
 676         if (shmseg->shm_perm.mode & SHMSEG_REMOVED) {
 677                 /*
 678                  * This segment is in the process of being allocated.  Wait
 679                  * until it's done, and look the key up again (in case the
 680                  * allocation failed or it was freed).
 681                  */
 682                 shmseg->shm_perm.mode |= SHMSEG_WANTED;
 683                 error = tsleep(shmseg, PLOCK | PCATCH, "shmget", 0);
 684                 if (error)
 685                         return (error);
 686                 return (EAGAIN);
 687         }
 688         if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
 689                 return (EEXIST);
 690         error = ipcperm(td, &shmseg->shm_perm, mode);
 691         if (error)
 692                 return (error);
 693         if (uap->size && uap->size > shmseg->shm_segsz)
 694                 return (EINVAL);
 695         td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
 696 #ifdef __CYGWIN__
 697         td->td_retval[1] =
 698                 vm_object_duplicate(td, shmseg->shm_internal->shm_object);
 699 #endif /* __CYGWIN__ */
 700         return (0);
 701 }
 702
 703 static int
 704 shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode)
 705 {
 706         int i, segnum, shmid, size;
 707 #ifndef __CYGWIN__
 708         struct ucred *cred = td->td_ucred;
 709 #endif /* __CYGWIN__ */
 710         struct shmid_ds *shmseg;
 711         struct shm_handle *shm_handle;
 712
 713         GIANT_REQUIRED;
 714
 715         if (uap->size < (unsigned long) shminfo.shmmin ||
 716             uap->size > (unsigned long) shminfo.shmmax)
 717                 return (EINVAL);
 718         if (shm_nused >= shminfo.shmmni) /* Any shmids left? */
 719                 return (ENOSPC);
 720         size = round_page(uap->size);
 721         if (shm_committed + btoc(size) > (unsigned long) shminfo.shmall)
 722                 return (ENOMEM);
 723         if (shm_last_free < 0) {
 724                 shmrealloc();   /* Maybe expand the shmsegs[] array. */
 725                 for (i = 0; i < shmalloced; i++)
 726                         if (shmsegs[i].shm_perm.mode & SHMSEG_FREE)
 727                                 break;
 728                 if (i == shmalloced)
 729                         return (ENOSPC);
 730                 segnum = i;
 731         } else  {
 732                 segnum = shm_last_free;
 733                 shm_last_free = -1;
 734         }
 735         shmseg = &shmsegs[segnum];
 736         /*
 737          * In case we sleep in malloc(), mark the segment present but deleted
 738          * so that noone else tries to create the same key.
 739          */
 740         shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED;
 741         shmseg->shm_perm.key = uap->key;
 742         shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff;
 743         shm_handle = (struct shm_handle *)
 744             sys_malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK);
 745         shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
 746
 747         /*
 748          * We make sure that we have allocated a pager before we need
 749          * to.
 750          */
 751         if (shm_use_phys) {
 752                 shm_handle->shm_object =
 753                     vm_pager_allocate(OBJT_PHYS, 0, size, VM_PROT_DEFAULT, 0);
 754         } else {
 755                 shm_handle->shm_object =
 756                     vm_pager_allocate(OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0);
 757         }
 758         VM_OBJECT_LOCK(shm_handle->shm_object);
 759         vm_object_clear_flag(shm_handle->shm_object, OBJ_ONEMAPPING);
 760         vm_object_set_flag(shm_handle->shm_object, OBJ_NOSPLIT);
 761         VM_OBJECT_UNLOCK(shm_handle->shm_object);
 762
 763         shmseg->shm_internal = shm_handle;
 764 #ifdef __CYGWIN__
 765         shmseg->shm_perm.cuid = shmseg->shm_perm.uid = td->ipcblk->uid;
 766         shmseg->shm_perm.cgid = shmseg->shm_perm.gid = td->ipcblk->gid;
 767 #else
 768         shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid;
 769         shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid;
 770 #endif /* __CYGWIN__ */
 771         shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) |
 772             (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
 773         shmseg->shm_segsz = uap->size;
 774         shmseg->shm_cpid = td->td_proc->p_pid;
 775         shmseg->shm_lpid = shmseg->shm_nattch = 0;
 776         shmseg->shm_atime = shmseg->shm_dtime = 0;
 777         shmseg->shm_ctime = time (NULL);
 778         shm_committed += btoc(size);
 779         shm_nused++;
 780         if (shmseg->shm_perm.mode & SHMSEG_WANTED) {
 781                 /*
 782                  * Somebody else wanted this key while we were asleep.  Wake
 783                  * them up now.
 784                  */
 785                 shmseg->shm_perm.mode &= ~SHMSEG_WANTED;
 786                 wakeup(shmseg);
 787         }
 788         td->td_retval[0] = shmid;
 789 #ifdef __CYGWIN__
 790         td->td_retval[1] =
 791                 vm_object_duplicate(td, shmseg->shm_internal->shm_object);
 792 #endif /* __CYGWIN__ */
 793         return (0);
 794 }
 795
 796 /*
 797  * MPSAFE
 798  */
 799 int
 800 shmget(struct thread *td, struct shmget_args *uap)
 801 {
 802         int segnum, mode;
 803         int error;
 804
 805         if (!jail_sysvipc_allowed && jailed(td->td_ucred))
 806                 return (ENOSYS);
 807         mtx_lock(&Giant);
 808         mode = uap->shmflg & ACCESSPERMS;
 809         if (uap->key != IPC_PRIVATE) {
 810         again:
 811 #ifdef __CYGWIN__
 812                 if (uap->shmflg & IPC_KEY_IS_SHMID)
 813                   segnum = shm_find_segment_by_shmid ((int) uap->key) ?
 814                            IPCID_TO_IX((int) uap->key) : -1;
 815                 else
 816 #endif
 817                 segnum = shm_find_segment_by_key(uap->key);
 818                 if (segnum >= 0) {
 819                         error = shmget_existing(td, uap, mode, segnum);
 820                         if (error == EAGAIN)
 821                                 goto again;
 822                         goto done2;
 823                 }
 824                 if ((uap->shmflg & IPC_CREAT) == 0) {
 825                         error = ENOENT;
 826                         goto done2;
 827                 }
 828         }
 829         error = shmget_allocate_segment(td, uap, mode);
 830 done2:
 831 #ifdef __CYGWIN__
 832         if (!error)
 833                 ipcexit_creat_hookthread (td);
 834 #endif
 835         mtx_unlock(&Giant);
 836         return (error);
 837 }
 838
 839 #ifndef __CYGWIN__
 840 /*
 841  * MPSAFE
 842  */
 843 int
 844 shmsys(td, uap)
 845         struct thread *td;
 846         /* XXX actually varargs. */
 847         struct shmsys_args /* {
 848                 int     which;
 849                 int     a2;
 850                 int     a3;
 851                 int     a4;
 852         } */ *uap;
 853 {
 854         int error;
 855
 856         if (!jail_sysvipc_allowed && jailed(td->td_ucred))
 857                 return (ENOSYS);
 858         if (uap->which < 0 ||
 859             uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
 860                 return (EINVAL);
 861         mtx_lock(&Giant);
 862         error = (*shmcalls[uap->which])(td, &uap->a2);
 863         mtx_unlock(&Giant);
 864         return (error);
 865 }
 866 #endif /* __CYGWIN__ */
 867
 868 static void
 869 shmfork_myhook(struct proc *p1, struct proc *p2)
 870 {
 871         struct shmmap_state *shmmap_s;
 872         size_t size;
 873         int i;
 874
 875         size = shminfo.shmseg * sizeof(struct shmmap_state);
 876         shmmap_s = (struct shmmap_state *) sys_malloc(size, M_SHM, M_WAITOK);
 877         bcopy(p1->p_vmspace->vm_shm, shmmap_s, size);
 878         p2->p_vmspace->vm_shm = shmmap_s;
 879         for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
 880                 if (shmmap_s->shmid != -1) {
 881                         shm_nattch++;
 882                         shmsegs[IPCID_TO_IX(shmmap_s->shmid)].shm_nattch++;
 883                 }
 884 }
 885
 886 #ifdef __CYGWIN__
 887 int cygwin_shmfork_myhook (struct thread *td, struct proc *parent)
 888 {
 889   ipcexit_creat_hookthread (td);
 890   ipc_p_vmspace (td->ipcblk);
 891   ipc_p_vmspace (parent);
 892   shmfork_myhook (parent, td->ipcblk);
 893   return 0;
 894 }
 895 #endif
 896
 897 void
 898 shmexit_myhook(struct vmspace *vm)
 899 {
 900         struct shmmap_state *base, *shm;
 901         int i;
 902
 903         GIANT_REQUIRED;
 904
 905         if ((base = vm->vm_shm) != NULL) {
 906                 vm->vm_shm = NULL;
 907                 for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) {
 908                         if (shm->shmid != -1)
 909                                 shm_delete_mapping(vm, shm);
 910                 }
 911                 sys_free(base, M_SHM);
 912         }
 913 }
 914
 915 static void
 916 shmrealloc(void)
 917 {
 918         int i;
 919         struct shmid_ds *newsegs;
 920
 921         if (shmalloced >= shminfo.shmmni)
 922                 return;
 923
 924         newsegs = (struct shmid_ds *) sys_malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK);
 925         if (newsegs == NULL)
 926                 return;
 927         for (i = 0; i < shmalloced; i++)
 928                 bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0]));
 929         for (; i < shminfo.shmmni; i++) {
 930                 shmsegs[i].shm_perm.mode = SHMSEG_FREE;
 931                 shmsegs[i].shm_perm.seq = 0;
 932         }
 933         sys_free(shmsegs, M_SHM);
 934         shmsegs = newsegs;
 935         shmalloced = shminfo.shmmni;
 936 }
 937
 938 void
 939 shminit(void)
 940 {
 941         int i;
 942
 943         TUNABLE_INT_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall);
 944         for (i = PAGE_SIZE; i > 0; i--) {
 945                 shminfo.shmmax = shminfo.shmall * PAGE_SIZE;
 946                 if (shminfo.shmmax >= shminfo.shmall)
 947                         break;
 948         }
 949         TUNABLE_INT_FETCH("kern.ipc.shmmin", &shminfo.shmmin);
 950         TUNABLE_INT_FETCH("kern.ipc.shmmni", &shminfo.shmmni);
 951         TUNABLE_INT_FETCH("kern.ipc.shmseg", &shminfo.shmseg);
 952         TUNABLE_INT_FETCH("kern.ipc.shm_use_phys", &shm_use_phys);
 953
 954         shmalloced = shminfo.shmmni;
 955         shmsegs = (struct shmid_ds *) sys_malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK);
 956         if (shmsegs == NULL)
 957                 panic("cannot allocate initial memory for sysvshm");
 958         for (i = 0; i < shmalloced; i++) {
 959                 shmsegs[i].shm_perm.mode = SHMSEG_FREE;
 960                 shmsegs[i].shm_perm.seq = 0;
 961         }
 962         shm_last_free = 0;
 963         shm_nused = 0;
 964         shm_committed = 0;
 965 #ifndef __CYGWIN__
 966         shmexit_hook = &shmexit_myhook;
 967         shmfork_hook = &shmfork_myhook;
 968 #endif /* __CYGWIN__ */
 969 }
 970
 971 int
 972 shmunload(void)
 973 {
 974
 975         if (shm_nused > 0)
 976                 return (EBUSY);
 977
 978         sys_free(shmsegs, M_SHM);
 979 #ifndef __CYGWIN__
 980         shmexit_hook = NULL;
 981         shmfork_hook = NULL;
 982 #endif /* __CYGWIN__ */
 983         return (0);
 984 }
 985
 986 #ifndef __CYGWIN__
 987 static int
 988 sysctl_shmsegs(SYSCTL_HANDLER_ARGS)
 989 {
 990
 991         return (SYSCTL_OUT(req, shmsegs, shmalloced * sizeof(shmsegs[0])));
 992 }
 993
 994 static int
 995 sysvshm_modload(struct module *module, int cmd, void *arg)
 996 {
 997         int error = 0;
 998
 999         switch (cmd) {
1000         case MOD_LOAD:
1001                 shminit();
1002                 break;
1003         case MOD_UNLOAD:
1004                 error = shmunload();
1005                 break;
1006         case MOD_SHUTDOWN:
1007                 break;
1008         default:
1009                 error = EINVAL;
1010                 break;
1011         }
1012         return (error);
1013 }
1014
1015 static moduledata_t sysvshm_mod = {
1016         "sysvshm",
1017         &sysvshm_modload,
1018         NULL
1019 };
1020
1021 SYSCALL_MODULE_HELPER(shmsys);
1022 SYSCALL_MODULE_HELPER(shmat);
1023 SYSCALL_MODULE_HELPER(shmctl);
1024 SYSCALL_MODULE_HELPER(shmdt);
1025 SYSCALL_MODULE_HELPER(shmget);
1026
1027 DECLARE_MODULE(sysvshm, sysvshm_mod,
1028         SI_SUB_SYSV_SHM, SI_ORDER_FIRST);
1029 MODULE_VERSION(sysvshm, 1);
1030 #endif /* __CYGWIN__ */
1031 #endif /* __OUTSIDE_CYGWIN__ */