ipc/shm.c

   1 /*
   2  * linux/ipc/shm.c
   3  * Copyright (C) 1992, 1993 Krishna Balasubramanian
   4  *       Many improvements/fixes by Bruno Haible.
   5  * Replaced `struct shm_desc' by `struct vm_area_struct', July 1994.
   6  * Fixed the shm swap deallocation (shm_unuse()), August 1998 Andrea Arcangeli.
   7  *
   8  * /proc/sysvipc/shm support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
   9  * BIGMEM support, Andrea Arcangeli <andrea@suse.de>
  10  * SMP thread shm, Jean-Luc Boyard <jean-luc.boyard@siemens.fr>
  11  * HIGHMEM support, Ingo Molnar <mingo@redhat.com>
  12  * Make shmmax, shmall, shmmni sysctl'able, Christoph Rohland <cr@sap.com>
  13  * Shared /dev/zero support, Kanoj Sarcar <kanoj@sgi.com>
  14  * Move the mm functionality over to mm/shmem.c, Christoph Rohland <cr@sap.com>
  15  *
  16  * support for audit of ipc object properties and permission changes
  17  * Dustin Kirkland <dustin.kirkland@us.ibm.com>
  18  *
  19  * namespaces support
  20  * OpenVZ, SWsoft Inc.
  21  * Pavel Emelianov <xemul@openvz.org>
  22  *
  23  * Better ipc lock (kern_ipc_perm.lock) handling
  24  * Davidlohr Bueso <davidlohr.bueso@hp.com>, June 2013.
  25  */
  26
  27 #include <linux/slab.h>
  28 #include <linux/mm.h>
  29 #include <linux/hugetlb.h>
  30 #include <linux/shm.h>
  31 #include <linux/init.h>
  32 #include <linux/file.h>
  33 #include <linux/mman.h>
  34 #include <linux/shmem_fs.h>
  35 #include <linux/security.h>
  36 #include <linux/syscalls.h>
  37 #include <linux/audit.h>
  38 #include <linux/capability.h>
  39 #include <linux/ptrace.h>
  40 #include <linux/seq_file.h>
  41 #include <linux/rwsem.h>
  42 #include <linux/nsproxy.h>
  43 #include <linux/mount.h>
  44 #include <linux/ipc_namespace.h>
  45
  46 #include <linux/uaccess.h>
  47
  48 #include "util.h"
  49
  50 struct shm_file_data {
  51         int id;
  52         struct ipc_namespace *ns;
  53         struct file *file;
  54         const struct vm_operations_struct *vm_ops;
  55 };
  56
  57 #define shm_file_data(file) (*((struct shm_file_data **)&(file)->private_data))
  58
  59 static const struct file_operations shm_file_operations;
  60 static const struct vm_operations_struct shm_vm_ops;
  61
  62 #define shm_ids(ns)     ((ns)->ids[IPC_SHM_IDS])
  63
  64 #define shm_unlock(shp)                 \
  65         ipc_unlock(&(shp)->shm_perm)
  66
  67 static int newseg(struct ipc_namespace *, struct ipc_params *);
  68 static void shm_open(struct vm_area_struct *vma);
  69 static void shm_close(struct vm_area_struct *vma);
  70 static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
  71 #ifdef CONFIG_PROC_FS
  72 static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
  73 #endif
  74
  75 void shm_init_ns(struct ipc_namespace *ns)
  76 {
  77         ns->shm_ctlmax = SHMMAX;
  78         ns->shm_ctlall = SHMALL;
  79         ns->shm_ctlmni = SHMMNI;
  80         ns->shm_rmid_forced = 0;
  81         ns->shm_tot = 0;
  82         ipc_init_ids(&shm_ids(ns));
  83 }
  84
  85 /*
  86  * Called with shm_ids.rwsem (writer) and the shp structure locked.
  87  * Only shm_ids.rwsem remains locked on exit.
  88  */
  89 static void do_shm_rmid(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
  90 {
  91         struct shmid_kernel *shp;
  92         shp = container_of(ipcp, struct shmid_kernel, shm_perm);
  93
  94         if (shp->shm_nattch) {
  95                 shp->shm_perm.mode |= SHM_DEST;
  96                 /* Do not find it any more */
  97                 shp->shm_perm.key = IPC_PRIVATE;
  98                 shm_unlock(shp);
  99         } else
 100                 shm_destroy(ns, shp);
 101 }
 102
 103 #ifdef CONFIG_IPC_NS
 104 void shm_exit_ns(struct ipc_namespace *ns)
 105 {
 106         free_ipcs(ns, &shm_ids(ns), do_shm_rmid);
 107         idr_destroy(&ns->ids[IPC_SHM_IDS].ipcs_idr);
 108 }
 109 #endif
 110
 111 static int __init ipc_ns_init(void)
 112 {
 113         shm_init_ns(&init_ipc_ns);
 114         return 0;
 115 }
 116
 117 pure_initcall(ipc_ns_init);
 118
 119 void __init shm_init(void)
 120 {
 121         ipc_init_proc_interface("sysvipc/shm",
 122 #if BITS_PER_LONG <= 32
 123                                 "       key      shmid perms       size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime        rss       swap\n",
 124 #else
 125                                 "       key      shmid perms                  size  cpid  lpid nattch   uid   gid  cuid  cgid      atime      dtime      ctime                   rss                  swap\n",
 126 #endif
 127                                 IPC_SHM_IDS, sysvipc_shm_proc_show);
 128 }
 129
 130 static inline struct shmid_kernel *shm_obtain_object(struct ipc_namespace *ns, int id)
 131 {
 132         struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&shm_ids(ns), id);
 133
 134         if (IS_ERR(ipcp))
 135                 return ERR_CAST(ipcp);
 136
 137         return container_of(ipcp, struct shmid_kernel, shm_perm);
 138 }
 139
 140 static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace *ns, int id)
 141 {
 142         struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&shm_ids(ns), id);
 143
 144         if (IS_ERR(ipcp))
 145                 return ERR_CAST(ipcp);
 146
 147         return container_of(ipcp, struct shmid_kernel, shm_perm);
 148 }
 149
 150 /*
 151  * shm_lock_(check_) routines are called in the paths where the rwsem
 152  * is not necessarily held.
 153  */
 154 static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
 155 {
 156         struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
 157
 158         /*
 159          * We raced in the idr lookup or with shm_destroy().  Either way, the
 160          * ID is busted.
 161          */
 162         WARN_ON(IS_ERR(ipcp));
 163
 164         return container_of(ipcp, struct shmid_kernel, shm_perm);
 165 }
 166
 167 static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
 168 {
 169         rcu_read_lock();
 170         ipc_lock_object(&ipcp->shm_perm);
 171 }
 172
 173 static void shm_rcu_free(struct rcu_head *head)
 174 {
 175         struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
 176         struct shmid_kernel *shp = ipc_rcu_to_struct(p);
 177
 178         security_shm_free(shp);
 179         ipc_rcu_free(head);
 180 }
 181
 182 static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
 183 {
 184         list_del(&s->shm_clist);
 185         ipc_rmid(&shm_ids(ns), &s->shm_perm);
 186 }
 187
 188
 189 /* This is called by fork, once for every shm attach. */
 190 static void shm_open(struct vm_area_struct *vma)
 191 {
 192         struct file *file = vma->vm_file;
 193         struct shm_file_data *sfd = shm_file_data(file);
 194         struct shmid_kernel *shp;
 195
 196         shp = shm_lock(sfd->ns, sfd->id);
 197         shp->shm_atim = get_seconds();
 198         shp->shm_lprid = task_tgid_vnr(current);
 199         shp->shm_nattch++;
 200         shm_unlock(shp);
 201 }
 202
 203 /*
 204  * shm_destroy - free the struct shmid_kernel
 205  *
 206  * @ns: namespace
 207  * @shp: struct to free
 208  *
 209  * It has to be called with shp and shm_ids.rwsem (writer) locked,
 210  * but returns with shp unlocked and freed.
 211  */
 212 static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
 213 {
 214         struct file *shm_file;
 215
 216         shm_file = shp->shm_file;
 217         shp->shm_file = NULL;
 218         ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
 219         shm_rmid(ns, shp);
 220         shm_unlock(shp);
 221         if (!is_file_hugepages(shm_file))
 222                 shmem_lock(shm_file, 0, shp->mlock_user);
 223         else if (shp->mlock_user)
 224                 user_shm_unlock(i_size_read(file_inode(shm_file)),
 225                                 shp->mlock_user);
 226         fput(shm_file);
 227         ipc_rcu_putref(shp, shm_rcu_free);
 228 }
 229
 230 /*
 231  * shm_may_destroy - identifies whether shm segment should be destroyed now
 232  *
 233  * Returns true if and only if there are no active users of the segment and
 234  * one of the following is true:
 235  *
 236  * 1) shmctl(id, IPC_RMID, NULL) was called for this shp
 237  *
 238  * 2) sysctl kernel.shm_rmid_forced is set to 1.
 239  */
 240 static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
 241 {
 242         return (shp->shm_nattch == 0) &&
 243                (ns->shm_rmid_forced ||
 244                 (shp->shm_perm.mode & SHM_DEST));
 245 }
 246
 247 /*
 248  * remove the attach descriptor vma.
 249  * free memory for segment if it is marked destroyed.
 250  * The descriptor has already been removed from the current->mm->mmap list
 251  * and will later be kfree()d.
 252  */
 253 static void shm_close(struct vm_area_struct *vma)
 254 {
 255         struct file *file = vma->vm_file;
 256         struct shm_file_data *sfd = shm_file_data(file);
 257         struct shmid_kernel *shp;
 258         struct ipc_namespace *ns = sfd->ns;
 259
 260         down_write(&shm_ids(ns).rwsem);
 261         /* remove from the list of attaches of the shm segment */
 262         shp = shm_lock(ns, sfd->id);
 263         shp->shm_lprid = task_tgid_vnr(current);
 264         shp->shm_dtim = get_seconds();
 265         shp->shm_nattch--;
 266         if (shm_may_destroy(ns, shp))
 267                 shm_destroy(ns, shp);
 268         else
 269                 shm_unlock(shp);
 270         up_write(&shm_ids(ns).rwsem);
 271 }
 272
 273 /* Called with ns->shm_ids(ns).rwsem locked */
 274 static int shm_try_destroy_orphaned(int id, void *p, void *data)
 275 {
 276         struct ipc_namespace *ns = data;
 277         struct kern_ipc_perm *ipcp = p;
 278         struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 279
 280         /*
 281          * We want to destroy segments without users and with already
 282          * exit'ed originating process.
 283          *
 284          * As shp->* are changed under rwsem, it's safe to skip shp locking.
 285          */
 286         if (shp->shm_creator != NULL)
 287                 return 0;
 288
 289         if (shm_may_destroy(ns, shp)) {
 290                 shm_lock_by_ptr(shp);
 291                 shm_destroy(ns, shp);
 292         }
 293         return 0;
 294 }
 295
 296 void shm_destroy_orphaned(struct ipc_namespace *ns)
 297 {
 298         down_write(&shm_ids(ns).rwsem);
 299         if (shm_ids(ns).in_use)
 300                 idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
 301         up_write(&shm_ids(ns).rwsem);
 302 }
 303
 304 /* Locking assumes this will only be called with task == current */
 305 void exit_shm(struct task_struct *task)
 306 {
 307         struct ipc_namespace *ns = task->nsproxy->ipc_ns;
 308         struct shmid_kernel *shp, *n;
 309
 310         if (list_empty(&task->sysvshm.shm_clist))
 311                 return;
 312
 313         /*
 314          * If kernel.shm_rmid_forced is not set then only keep track of
 315          * which shmids are orphaned, so that a later set of the sysctl
 316          * can clean them up.
 317          */
 318         if (!ns->shm_rmid_forced) {
 319                 down_read(&shm_ids(ns).rwsem);
 320                 list_for_each_entry(shp, &task->sysvshm.shm_clist, shm_clist)
 321                         shp->shm_creator = NULL;
 322                 /*
 323                  * Only under read lock but we are only called on current
 324                  * so no entry on the list will be shared.
 325                  */
 326                 list_del(&task->sysvshm.shm_clist);
 327                 up_read(&shm_ids(ns).rwsem);
 328                 return;
 329         }
 330
 331         /*
 332          * Destroy all already created segments, that were not yet mapped,
 333          * and mark any mapped as orphan to cover the sysctl toggling.
 334          * Destroy is skipped if shm_may_destroy() returns false.
 335          */
 336         down_write(&shm_ids(ns).rwsem);
 337         list_for_each_entry_safe(shp, n, &task->sysvshm.shm_clist, shm_clist) {
 338                 shp->shm_creator = NULL;
 339
 340                 if (shm_may_destroy(ns, shp)) {
 341                         shm_lock_by_ptr(shp);
 342                         shm_destroy(ns, shp);
 343                 }
 344         }
 345
 346         /* Remove the list head from any segments still attached. */
 347         list_del(&task->sysvshm.shm_clist);
 348         up_write(&shm_ids(ns).rwsem);
 349 }
 350
 351 static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 352 {
 353         struct file *file = vma->vm_file;
 354         struct shm_file_data *sfd = shm_file_data(file);
 355
 356         return sfd->vm_ops->fault(vma, vmf);
 357 }
 358
 359 #ifdef CONFIG_NUMA
 360 static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
 361 {
 362         struct file *file = vma->vm_file;
 363         struct shm_file_data *sfd = shm_file_data(file);
 364         int err = 0;
 365         if (sfd->vm_ops->set_policy)
 366                 err = sfd->vm_ops->set_policy(vma, new);
 367         return err;
 368 }
 369
 370 static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
 371                                         unsigned long addr)
 372 {
 373         struct file *file = vma->vm_file;
 374         struct shm_file_data *sfd = shm_file_data(file);
 375         struct mempolicy *pol = NULL;
 376
 377         if (sfd->vm_ops->get_policy)
 378                 pol = sfd->vm_ops->get_policy(vma, addr);
 379         else if (vma->vm_policy)
 380                 pol = vma->vm_policy;
 381
 382         return pol;
 383 }
 384 #endif
 385
 386 static int shm_mmap(struct file *file, struct vm_area_struct *vma)
 387 {
 388         struct shm_file_data *sfd = shm_file_data(file);
 389         int ret;
 390
 391         ret = sfd->file->f_op->mmap(sfd->file, vma);
 392         if (ret != 0)
 393                 return ret;
 394         sfd->vm_ops = vma->vm_ops;
 395 #ifdef CONFIG_MMU
 396         WARN_ON(!sfd->vm_ops->fault);
 397 #endif
 398         vma->vm_ops = &shm_vm_ops;
 399         shm_open(vma);
 400
 401         return ret;
 402 }
 403
 404 static int shm_release(struct inode *ino, struct file *file)
 405 {
 406         struct shm_file_data *sfd = shm_file_data(file);
 407
 408         put_ipc_ns(sfd->ns);
 409         shm_file_data(file) = NULL;
 410         kfree(sfd);
 411         return 0;
 412 }
 413
 414 static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 415 {
 416         struct shm_file_data *sfd = shm_file_data(file);
 417
 418         if (!sfd->file->f_op->fsync)
 419                 return -EINVAL;
 420         return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
 421 }
 422
 423 static long shm_fallocate(struct file *file, int mode, loff_t offset,
 424                           loff_t len)
 425 {
 426         struct shm_file_data *sfd = shm_file_data(file);
 427
 428         if (!sfd->file->f_op->fallocate)
 429                 return -EOPNOTSUPP;
 430         return sfd->file->f_op->fallocate(file, mode, offset, len);
 431 }
 432
 433 static unsigned long shm_get_unmapped_area(struct file *file,
 434         unsigned long addr, unsigned long len, unsigned long pgoff,
 435         unsigned long flags)
 436 {
 437         struct shm_file_data *sfd = shm_file_data(file);
 438         return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
 439                                                 pgoff, flags);
 440 }
 441
 442 static const struct file_operations shm_file_operations = {
 443         .mmap           = shm_mmap,
 444         .fsync          = shm_fsync,
 445         .release        = shm_release,
 446 #ifndef CONFIG_MMU
 447         .get_unmapped_area      = shm_get_unmapped_area,
 448 #endif
 449         .llseek         = noop_llseek,
 450         .fallocate      = shm_fallocate,
 451 };
 452
 453 static const struct file_operations shm_file_operations_huge = {
 454         .mmap           = shm_mmap,
 455         .fsync          = shm_fsync,
 456         .release        = shm_release,
 457         .get_unmapped_area      = shm_get_unmapped_area,
 458         .llseek         = noop_llseek,
 459         .fallocate      = shm_fallocate,
 460 };
 461
 462 bool is_file_shm_hugepages(struct file *file)
 463 {
 464         return file->f_op == &shm_file_operations_huge;
 465 }
 466
 467 static const struct vm_operations_struct shm_vm_ops = {
 468         .open   = shm_open,     /* callback for a new vm-area open */
 469         .close  = shm_close,    /* callback for when the vm-area is released */
 470         .fault  = shm_fault,
 471 #if defined(CONFIG_NUMA)
 472         .set_policy = shm_set_policy,
 473         .get_policy = shm_get_policy,
 474 #endif
 475 };
 476
 477 /**
 478  * newseg - Create a new shared memory segment
 479  * @ns: namespace
 480  * @params: ptr to the structure that contains key, size and shmflg
 481  *
 482  * Called with shm_ids.rwsem held as a writer.
 483  */
 484 static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
 485 {
 486         key_t key = params->key;
 487         int shmflg = params->flg;
 488         size_t size = params->u.size;
 489         int error;
 490         struct shmid_kernel *shp;
 491         size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 492         struct file *file;
 493         char name[13];
 494         int id;
 495         vm_flags_t acctflag = 0;
 496
 497         if (size < SHMMIN || size > ns->shm_ctlmax)
 498                 return -EINVAL;
 499
 500         if (numpages << PAGE_SHIFT < size)
 501                 return -ENOSPC;
 502
 503         if (ns->shm_tot + numpages < ns->shm_tot ||
 504                         ns->shm_tot + numpages > ns->shm_ctlall)
 505                 return -ENOSPC;
 506
 507         shp = ipc_rcu_alloc(sizeof(*shp));
 508         if (!shp)
 509                 return -ENOMEM;
 510
 511         shp->shm_perm.key = key;
 512         shp->shm_perm.mode = (shmflg & S_IRWXUGO);
 513         shp->mlock_user = NULL;
 514
 515         shp->shm_perm.security = NULL;
 516         error = security_shm_alloc(shp);
 517         if (error) {
 518                 ipc_rcu_putref(shp, ipc_rcu_free);
 519                 return error;
 520         }
 521
 522         sprintf(name, "SYSV%08x", key);
 523         if (shmflg & SHM_HUGETLB) {
 524                 struct hstate *hs;
 525                 size_t hugesize;
 526
 527                 hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
 528                 if (!hs) {
 529                         error = -EINVAL;
 530                         goto no_file;
 531                 }
 532                 hugesize = ALIGN(size, huge_page_size(hs));
 533
 534                 /* hugetlb_file_setup applies strict accounting */
 535                 if (shmflg & SHM_NORESERVE)
 536                         acctflag = VM_NORESERVE;
 537                 file = hugetlb_file_setup(name, hugesize, acctflag,
 538                                   &shp->mlock_user, HUGETLB_SHMFS_INODE,
 539                                 (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
 540         } else {
 541                 /*
 542                  * Do not allow no accounting for OVERCOMMIT_NEVER, even
 543                  * if it's asked for.
 544                  */
 545                 if  ((shmflg & SHM_NORESERVE) &&
 546                                 sysctl_overcommit_memory != OVERCOMMIT_NEVER)
 547                         acctflag = VM_NORESERVE;
 548                 file = shmem_kernel_file_setup(name, size, acctflag);
 549         }
 550         error = PTR_ERR(file);
 551         if (IS_ERR(file))
 552                 goto no_file;
 553
 554         shp->shm_cprid = task_tgid_vnr(current);
 555         shp->shm_lprid = 0;
 556         shp->shm_atim = shp->shm_dtim = 0;
 557         shp->shm_ctim = get_seconds();
 558         shp->shm_segsz = size;
 559         shp->shm_nattch = 0;
 560         shp->shm_file = file;
 561         shp->shm_creator = current;
 562
 563         id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
 564         if (id < 0) {
 565                 error = id;
 566                 goto no_id;
 567         }
 568
 569         list_add(&shp->shm_clist, &current->sysvshm.shm_clist);
 570
 571         /*
 572          * shmid gets reported as "inode#" in /proc/pid/maps.
 573          * proc-ps tools use this. Changing this will break them.
 574          */
 575         file_inode(file)->i_ino = shp->shm_perm.id;
 576
 577         ns->shm_tot += numpages;
 578         error = shp->shm_perm.id;
 579
 580         ipc_unlock_object(&shp->shm_perm);
 581         rcu_read_unlock();
 582         return error;
 583
 584 no_id:
 585         if (is_file_hugepages(file) && shp->mlock_user)
 586                 user_shm_unlock(size, shp->mlock_user);
 587         fput(file);
 588 no_file:
 589         ipc_rcu_putref(shp, shm_rcu_free);
 590         return error;
 591 }
 592
 593 /*
 594  * Called with shm_ids.rwsem and ipcp locked.
 595  */
 596 static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
 597 {
 598         struct shmid_kernel *shp;
 599
 600         shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 601         return security_shm_associate(shp, shmflg);
 602 }
 603
 604 /*
 605  * Called with shm_ids.rwsem and ipcp locked.
 606  */
 607 static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
 608                                 struct ipc_params *params)
 609 {
 610         struct shmid_kernel *shp;
 611
 612         shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 613         if (shp->shm_segsz < params->u.size)
 614                 return -EINVAL;
 615
 616         return 0;
 617 }
 618
 619 SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
 620 {
 621         struct ipc_namespace *ns;
 622         static const struct ipc_ops shm_ops = {
 623                 .getnew = newseg,
 624                 .associate = shm_security,
 625                 .more_checks = shm_more_checks,
 626         };
 627         struct ipc_params shm_params;
 628
 629         ns = current->nsproxy->ipc_ns;
 630
 631         shm_params.key = key;
 632         shm_params.flg = shmflg;
 633         shm_params.u.size = size;
 634
 635         return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
 636 }
 637
 638 static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
 639 {
 640         switch (version) {
 641         case IPC_64:
 642                 return copy_to_user(buf, in, sizeof(*in));
 643         case IPC_OLD:
 644             {
 645                 struct shmid_ds out;
 646
 647                 memset(&out, 0, sizeof(out));
 648                 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
 649                 out.shm_segsz   = in->shm_segsz;
 650                 out.shm_atime   = in->shm_atime;
 651                 out.shm_dtime   = in->shm_dtime;
 652                 out.shm_ctime   = in->shm_ctime;
 653                 out.shm_cpid    = in->shm_cpid;
 654                 out.shm_lpid    = in->shm_lpid;
 655                 out.shm_nattch  = in->shm_nattch;
 656
 657                 return copy_to_user(buf, &out, sizeof(out));
 658             }
 659         default:
 660                 return -EINVAL;
 661         }
 662 }
 663
 664 static inline unsigned long
 665 copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
 666 {
 667         switch (version) {
 668         case IPC_64:
 669                 if (copy_from_user(out, buf, sizeof(*out)))
 670                         return -EFAULT;
 671                 return 0;
 672         case IPC_OLD:
 673             {
 674                 struct shmid_ds tbuf_old;
 675
 676                 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
 677                         return -EFAULT;
 678
 679                 out->shm_perm.uid       = tbuf_old.shm_perm.uid;
 680                 out->shm_perm.gid       = tbuf_old.shm_perm.gid;
 681                 out->shm_perm.mode      = tbuf_old.shm_perm.mode;
 682
 683                 return 0;
 684             }
 685         default:
 686                 return -EINVAL;
 687         }
 688 }
 689
 690 static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
 691 {
 692         switch (version) {
 693         case IPC_64:
 694                 return copy_to_user(buf, in, sizeof(*in));
 695         case IPC_OLD:
 696             {
 697                 struct shminfo out;
 698
 699                 if (in->shmmax > INT_MAX)
 700                         out.shmmax = INT_MAX;
 701                 else
 702                         out.shmmax = (int)in->shmmax;
 703
 704                 out.shmmin      = in->shmmin;
 705                 out.shmmni      = in->shmmni;
 706                 out.shmseg      = in->shmseg;
 707                 out.shmall      = in->shmall;
 708
 709                 return copy_to_user(buf, &out, sizeof(out));
 710             }
 711         default:
 712                 return -EINVAL;
 713         }
 714 }
 715
 716 /*
 717  * Calculate and add used RSS and swap pages of a shm.
 718  * Called with shm_ids.rwsem held as a reader
 719  */
 720 static void shm_add_rss_swap(struct shmid_kernel *shp,
 721         unsigned long *rss_add, unsigned long *swp_add)
 722 {
 723         struct inode *inode;
 724
 725         inode = file_inode(shp->shm_file);
 726
 727         if (is_file_hugepages(shp->shm_file)) {
 728                 struct address_space *mapping = inode->i_mapping;
 729                 struct hstate *h = hstate_file(shp->shm_file);
 730                 *rss_add += pages_per_huge_page(h) * mapping->nrpages;
 731         } else {
 732 #ifdef CONFIG_SHMEM
 733                 struct shmem_inode_info *info = SHMEM_I(inode);
 734                 spin_lock(&info->lock);
 735                 *rss_add += inode->i_mapping->nrpages;
 736                 *swp_add += info->swapped;
 737                 spin_unlock(&info->lock);
 738 #else
 739                 *rss_add += inode->i_mapping->nrpages;
 740 #endif
 741         }
 742 }
 743
 744 /*
 745  * Called with shm_ids.rwsem held as a reader
 746  */
 747 static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
 748                 unsigned long *swp)
 749 {
 750         int next_id;
 751         int total, in_use;
 752
 753         *rss = 0;
 754         *swp = 0;
 755
 756         in_use = shm_ids(ns).in_use;
 757
 758         for (total = 0, next_id = 0; total < in_use; next_id++) {
 759                 struct kern_ipc_perm *ipc;
 760                 struct shmid_kernel *shp;
 761
 762                 ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
 763                 if (ipc == NULL)
 764                         continue;
 765                 shp = container_of(ipc, struct shmid_kernel, shm_perm);
 766
 767                 shm_add_rss_swap(shp, rss, swp);
 768
 769                 total++;
 770         }
 771 }
 772
 773 /*
 774  * This function handles some shmctl commands which require the rwsem
 775  * to be held in write mode.
 776  * NOTE: no locks must be held, the rwsem is taken inside this function.
 777  */
 778 static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
 779                        struct shmid_ds __user *buf, int version)
 780 {
 781         struct kern_ipc_perm *ipcp;
 782         struct shmid64_ds shmid64;
 783         struct shmid_kernel *shp;
 784         int err;
 785
 786         if (cmd == IPC_SET) {
 787                 if (copy_shmid_from_user(&shmid64, buf, version))
 788                         return -EFAULT;
 789         }
 790
 791         down_write(&shm_ids(ns).rwsem);
 792         rcu_read_lock();
 793
 794         ipcp = ipcctl_pre_down_nolock(ns, &shm_ids(ns), shmid, cmd,
 795                                       &shmid64.shm_perm, 0);
 796         if (IS_ERR(ipcp)) {
 797                 err = PTR_ERR(ipcp);
 798                 goto out_unlock1;
 799         }
 800
 801         shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 802
 803         err = security_shm_shmctl(shp, cmd);
 804         if (err)
 805                 goto out_unlock1;
 806
 807         switch (cmd) {
 808         case IPC_RMID:
 809                 ipc_lock_object(&shp->shm_perm);
 810                 /* do_shm_rmid unlocks the ipc object and rcu */
 811                 do_shm_rmid(ns, ipcp);
 812                 goto out_up;
 813         case IPC_SET:
 814                 ipc_lock_object(&shp->shm_perm);
 815                 err = ipc_update_perm(&shmid64.shm_perm, ipcp);
 816                 if (err)
 817                         goto out_unlock0;
 818                 shp->shm_ctim = get_seconds();
 819                 break;
 820         default:
 821                 err = -EINVAL;
 822                 goto out_unlock1;
 823         }
 824
 825 out_unlock0:
 826         ipc_unlock_object(&shp->shm_perm);
 827 out_unlock1:
 828         rcu_read_unlock();
 829 out_up:
 830         up_write(&shm_ids(ns).rwsem);
 831         return err;
 832 }
 833
 834 static int shmctl_nolock(struct ipc_namespace *ns, int shmid,
 835                          int cmd, int version, void __user *buf)
 836 {
 837         int err;
 838         struct shmid_kernel *shp;
 839
 840         /* preliminary security checks for *_INFO */
 841         if (cmd == IPC_INFO || cmd == SHM_INFO) {
 842                 err = security_shm_shmctl(NULL, cmd);
 843                 if (err)
 844                         return err;
 845         }
 846
 847         switch (cmd) {
 848         case IPC_INFO:
 849         {
 850                 struct shminfo64 shminfo;
 851
 852                 memset(&shminfo, 0, sizeof(shminfo));
 853                 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
 854                 shminfo.shmmax = ns->shm_ctlmax;
 855                 shminfo.shmall = ns->shm_ctlall;
 856
 857                 shminfo.shmmin = SHMMIN;
 858                 if (copy_shminfo_to_user(buf, &shminfo, version))
 859                         return -EFAULT;
 860
 861                 down_read(&shm_ids(ns).rwsem);
 862                 err = ipc_get_maxid(&shm_ids(ns));
 863                 up_read(&shm_ids(ns).rwsem);
 864
 865                 if (err < 0)
 866                         err = 0;
 867                 goto out;
 868         }
 869         case SHM_INFO:
 870         {
 871                 struct shm_info shm_info;
 872
 873                 memset(&shm_info, 0, sizeof(shm_info));
 874                 down_read(&shm_ids(ns).rwsem);
 875                 shm_info.used_ids = shm_ids(ns).in_use;
 876                 shm_get_stat(ns, &shm_info.shm_rss, &shm_info.shm_swp);
 877                 shm_info.shm_tot = ns->shm_tot;
 878                 shm_info.swap_attempts = 0;
 879                 shm_info.swap_successes = 0;
 880                 err = ipc_get_maxid(&shm_ids(ns));
 881                 up_read(&shm_ids(ns).rwsem);
 882                 if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {
 883                         err = -EFAULT;
 884                         goto out;
 885                 }
 886
 887                 err = err < 0 ? 0 : err;
 888                 goto out;
 889         }
 890         case SHM_STAT:
 891         case IPC_STAT:
 892         {
 893                 struct shmid64_ds tbuf;
 894                 int result;
 895
 896                 rcu_read_lock();
 897                 if (cmd == SHM_STAT) {
 898                         shp = shm_obtain_object(ns, shmid);
 899                         if (IS_ERR(shp)) {
 900                                 err = PTR_ERR(shp);
 901                                 goto out_unlock;
 902                         }
 903                         result = shp->shm_perm.id;
 904                 } else {
 905                         shp = shm_obtain_object_check(ns, shmid);
 906                         if (IS_ERR(shp)) {
 907                                 err = PTR_ERR(shp);
 908                                 goto out_unlock;
 909                         }
 910                         result = 0;
 911                 }
 912
 913                 err = -EACCES;
 914                 if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
 915                         goto out_unlock;
 916
 917                 err = security_shm_shmctl(shp, cmd);
 918                 if (err)
 919                         goto out_unlock;
 920
 921                 memset(&tbuf, 0, sizeof(tbuf));
 922                 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
 923                 tbuf.shm_segsz  = shp->shm_segsz;
 924                 tbuf.shm_atime  = shp->shm_atim;
 925                 tbuf.shm_dtime  = shp->shm_dtim;
 926                 tbuf.shm_ctime  = shp->shm_ctim;
 927                 tbuf.shm_cpid   = shp->shm_cprid;
 928                 tbuf.shm_lpid   = shp->shm_lprid;
 929                 tbuf.shm_nattch = shp->shm_nattch;
 930                 rcu_read_unlock();
 931
 932                 if (copy_shmid_to_user(buf, &tbuf, version))
 933                         err = -EFAULT;
 934                 else
 935                         err = result;
 936                 goto out;
 937         }
 938         default:
 939                 return -EINVAL;
 940         }
 941
 942 out_unlock:
 943         rcu_read_unlock();
 944 out:
 945         return err;
 946 }
 947
 948 SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 949 {
 950         struct shmid_kernel *shp;
 951         int err, version;
 952         struct ipc_namespace *ns;
 953
 954         if (cmd < 0 || shmid < 0)
 955                 return -EINVAL;
 956
 957         version = ipc_parse_version(&cmd);
 958         ns = current->nsproxy->ipc_ns;
 959
 960         switch (cmd) {
 961         case IPC_INFO:
 962         case SHM_INFO:
 963         case SHM_STAT:
 964         case IPC_STAT:
 965                 return shmctl_nolock(ns, shmid, cmd, version, buf);
 966         case IPC_RMID:
 967         case IPC_SET:
 968                 return shmctl_down(ns, shmid, cmd, buf, version);
 969         case SHM_LOCK:
 970         case SHM_UNLOCK:
 971         {
 972                 struct file *shm_file;
 973
 974                 rcu_read_lock();
 975                 shp = shm_obtain_object_check(ns, shmid);
 976                 if (IS_ERR(shp)) {
 977                         err = PTR_ERR(shp);
 978                         goto out_unlock1;
 979                 }
 980
 981                 audit_ipc_obj(&(shp->shm_perm));
 982                 err = security_shm_shmctl(shp, cmd);
 983                 if (err)
 984                         goto out_unlock1;
 985
 986                 ipc_lock_object(&shp->shm_perm);
 987
 988                 /* check if shm_destroy() is tearing down shp */
 989                 if (!ipc_valid_object(&shp->shm_perm)) {
 990                         err = -EIDRM;
 991                         goto out_unlock0;
 992                 }
 993
 994                 if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
 995                         kuid_t euid = current_euid();
 996                         if (!uid_eq(euid, shp->shm_perm.uid) &&
 997                             !uid_eq(euid, shp->shm_perm.cuid)) {
 998                                 err = -EPERM;
 999                                 goto out_unlock0;
1000                         }
1001                         if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) {
1002                                 err = -EPERM;
1003                                 goto out_unlock0;
1004                         }
1005                 }
1006
1007                 shm_file = shp->shm_file;
1008                 if (is_file_hugepages(shm_file))
1009                         goto out_unlock0;
1010
1011                 if (cmd == SHM_LOCK) {
1012                         struct user_struct *user = current_user();
1013                         err = shmem_lock(shm_file, 1, user);
1014                         if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
1015                                 shp->shm_perm.mode |= SHM_LOCKED;
1016                                 shp->mlock_user = user;
1017                         }
1018                         goto out_unlock0;
1019                 }
1020
1021                 /* SHM_UNLOCK */
1022                 if (!(shp->shm_perm.mode & SHM_LOCKED))
1023                         goto out_unlock0;
1024                 shmem_lock(shm_file, 0, shp->mlock_user);
1025                 shp->shm_perm.mode &= ~SHM_LOCKED;
1026                 shp->mlock_user = NULL;
1027                 get_file(shm_file);
1028                 ipc_unlock_object(&shp->shm_perm);
1029                 rcu_read_unlock();
1030                 shmem_unlock_mapping(shm_file->f_mapping);
1031
1032                 fput(shm_file);
1033                 return err;
1034         }
1035         default:
1036                 return -EINVAL;
1037         }
1038
1039 out_unlock0:
1040         ipc_unlock_object(&shp->shm_perm);
1041 out_unlock1:
1042         rcu_read_unlock();
1043         return err;
1044 }
1045
1046 /*
1047  * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
1048  *
1049  * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
1050  * "raddr" thing points to kernel space, and there has to be a wrapper around
1051  * this.
1052  */
1053 long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
1054               unsigned long shmlba)
1055 {
1056         struct shmid_kernel *shp;
1057         unsigned long addr;
1058         unsigned long size;
1059         struct file *file;
1060         int    err;
1061         unsigned long flags;
1062         unsigned long prot;
1063         int acc_mode;
1064         struct ipc_namespace *ns;
1065         struct shm_file_data *sfd;
1066         struct path path;
1067         fmode_t f_mode;
1068         unsigned long populate = 0;
1069
1070         err = -EINVAL;
1071         if (shmid < 0)
1072                 goto out;
1073         else if ((addr = (ulong)shmaddr)) {
1074                 if (addr & (shmlba - 1)) {
1075                         if (shmflg & SHM_RND)
1076                                 addr &= ~(shmlba - 1);     /* round down */
1077                         else
1078 #ifndef __ARCH_FORCE_SHMLBA
1079                                 if (addr & ~PAGE_MASK)
1080 #endif
1081                                         goto out;
1082                 }
1083                 flags = MAP_SHARED | MAP_FIXED;
1084         } else {
1085                 if ((shmflg & SHM_REMAP))
1086                         goto out;
1087
1088                 flags = MAP_SHARED;
1089         }
1090
1091         if (shmflg & SHM_RDONLY) {
1092                 prot = PROT_READ;
1093                 acc_mode = S_IRUGO;
1094                 f_mode = FMODE_READ;
1095         } else {
1096                 prot = PROT_READ | PROT_WRITE;
1097                 acc_mode = S_IRUGO | S_IWUGO;
1098                 f_mode = FMODE_READ | FMODE_WRITE;
1099         }
1100         if (shmflg & SHM_EXEC) {
1101                 prot |= PROT_EXEC;
1102                 acc_mode |= S_IXUGO;
1103         }
1104
1105         /*
1106          * We cannot rely on the fs check since SYSV IPC does have an
1107          * additional creator id...
1108          */
1109         ns = current->nsproxy->ipc_ns;
1110         rcu_read_lock();
1111         shp = shm_obtain_object_check(ns, shmid);
1112         if (IS_ERR(shp)) {
1113                 err = PTR_ERR(shp);
1114                 goto out_unlock;
1115         }
1116
1117         err = -EACCES;
1118         if (ipcperms(ns, &shp->shm_perm, acc_mode))
1119                 goto out_unlock;
1120
1121         err = security_shm_shmat(shp, shmaddr, shmflg);
1122         if (err)
1123                 goto out_unlock;
1124
1125         ipc_lock_object(&shp->shm_perm);
1126
1127         /* check if shm_destroy() is tearing down shp */
1128         if (!ipc_valid_object(&shp->shm_perm)) {
1129                 ipc_unlock_object(&shp->shm_perm);
1130                 err = -EIDRM;
1131                 goto out_unlock;
1132         }
1133
1134         path = shp->shm_file->f_path;
1135         path_get(&path);
1136         shp->shm_nattch++;
1137         size = i_size_read(d_inode(path.dentry));
1138         ipc_unlock_object(&shp->shm_perm);
1139         rcu_read_unlock();
1140
1141         err = -ENOMEM;
1142         sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
1143         if (!sfd) {
1144                 path_put(&path);
1145                 goto out_nattch;
1146         }
1147
1148         file = alloc_file(&path, f_mode,
1149                           is_file_hugepages(shp->shm_file) ?
1150                                 &shm_file_operations_huge :
1151                                 &shm_file_operations);
1152         err = PTR_ERR(file);
1153         if (IS_ERR(file)) {
1154                 kfree(sfd);
1155                 path_put(&path);
1156                 goto out_nattch;
1157         }
1158
1159         file->private_data = sfd;
1160         file->f_mapping = shp->shm_file->f_mapping;
1161         sfd->id = shp->shm_perm.id;
1162         sfd->ns = get_ipc_ns(ns);
1163         sfd->file = shp->shm_file;
1164         sfd->vm_ops = NULL;
1165
1166         err = security_mmap_file(file, prot, flags);
1167         if (err)
1168                 goto out_fput;
1169
1170         down_write(&current->mm->mmap_sem);
1171         if (addr && !(shmflg & SHM_REMAP)) {
1172                 err = -EINVAL;
1173                 if (addr + size < addr)
1174                         goto invalid;
1175
1176                 if (find_vma_intersection(current->mm, addr, addr + size))
1177                         goto invalid;
1178         }
1179
1180         addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate);
1181         *raddr = addr;
1182         err = 0;
1183         if (IS_ERR_VALUE(addr))
1184                 err = (long)addr;
1185 invalid:
1186         up_write(&current->mm->mmap_sem);
1187         if (populate)
1188                 mm_populate(addr, populate);
1189
1190 out_fput:
1191         fput(file);
1192
1193 out_nattch:
1194         down_write(&shm_ids(ns).rwsem);
1195         shp = shm_lock(ns, shmid);
1196         shp->shm_nattch--;
1197         if (shm_may_destroy(ns, shp))
1198                 shm_destroy(ns, shp);
1199         else
1200                 shm_unlock(shp);
1201         up_write(&shm_ids(ns).rwsem);
1202         return err;
1203
1204 out_unlock:
1205         rcu_read_unlock();
1206 out:
1207         return err;
1208 }
1209
1210 SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
1211 {
1212         unsigned long ret;
1213         long err;
1214
1215         err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
1216         if (err)
1217                 return err;
1218         force_successful_syscall_return();
1219         return (long)ret;
1220 }
1221
1222 /*
1223  * detach and kill segment if marked destroyed.
1224  * The work is done in shm_close.
1225  */
1226 SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
1227 {
1228         struct mm_struct *mm = current->mm;
1229         struct vm_area_struct *vma;
1230         unsigned long addr = (unsigned long)shmaddr;
1231         int retval = -EINVAL;
1232 #ifdef CONFIG_MMU
1233         loff_t size = 0;
1234         struct file *file;
1235         struct vm_area_struct *next;
1236 #endif
1237
1238         if (addr & ~PAGE_MASK)
1239                 return retval;
1240
1241         down_write(&mm->mmap_sem);
1242
1243         /*
1244          * This function tries to be smart and unmap shm segments that
1245          * were modified by partial mlock or munmap calls:
1246          * - It first determines the size of the shm segment that should be
1247          *   unmapped: It searches for a vma that is backed by shm and that
1248          *   started at address shmaddr. It records it's size and then unmaps
1249          *   it.
1250          * - Then it unmaps all shm vmas that started at shmaddr and that
1251          *   are within the initially determined size and that are from the
1252          *   same shm segment from which we determined the size.
1253          * Errors from do_munmap are ignored: the function only fails if
1254          * it's called with invalid parameters or if it's called to unmap
1255          * a part of a vma. Both calls in this function are for full vmas,
1256          * the parameters are directly copied from the vma itself and always
1257          * valid - therefore do_munmap cannot fail. (famous last words?)
1258          */
1259         /*
1260          * If it had been mremap()'d, the starting address would not
1261          * match the usual checks anyway. So assume all vma's are
1262          * above the starting address given.
1263          */
1264         vma = find_vma(mm, addr);
1265
1266 #ifdef CONFIG_MMU
1267         while (vma) {
1268                 next = vma->vm_next;
1269
1270                 /*
1271                  * Check if the starting address would match, i.e. it's
1272                  * a fragment created by mprotect() and/or munmap(), or it
1273                  * otherwise it starts at this address with no hassles.
1274                  */
1275                 if ((vma->vm_ops == &shm_vm_ops) &&
1276                         (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
1277
1278                         /*
1279                          * Record the file of the shm segment being
1280                          * unmapped.  With mremap(), someone could place
1281                          * page from another segment but with equal offsets
1282                          * in the range we are unmapping.
1283                          */
1284                         file = vma->vm_file;
1285                         size = i_size_read(file_inode(vma->vm_file));
1286                         do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1287                         /*
1288                          * We discovered the size of the shm segment, so
1289                          * break out of here and fall through to the next
1290                          * loop that uses the size information to stop
1291                          * searching for matching vma's.
1292                          */
1293                         retval = 0;
1294                         vma = next;
1295                         break;
1296                 }
1297                 vma = next;
1298         }
1299
1300         /*
1301          * We need look no further than the maximum address a fragment
1302          * could possibly have landed at. Also cast things to loff_t to
1303          * prevent overflows and make comparisons vs. equal-width types.
1304          */
1305         size = PAGE_ALIGN(size);
1306         while (vma && (loff_t)(vma->vm_end - addr) <= size) {
1307                 next = vma->vm_next;
1308
1309                 /* finding a matching vma now does not alter retval */
1310                 if ((vma->vm_ops == &shm_vm_ops) &&
1311                     ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) &&
1312                     (vma->vm_file == file))
1313                         do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1314                 vma = next;
1315         }
1316
1317 #else /* CONFIG_MMU */
1318         /* under NOMMU conditions, the exact address to be destroyed must be
1319          * given */
1320         if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
1321                 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1322                 retval = 0;
1323         }
1324
1325 #endif
1326
1327         up_write(&mm->mmap_sem);
1328         return retval;
1329 }
1330
1331 #ifdef CONFIG_PROC_FS
1332 static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
1333 {
1334         struct user_namespace *user_ns = seq_user_ns(s);
1335         struct shmid_kernel *shp = it;
1336         unsigned long rss = 0, swp = 0;
1337
1338         shm_add_rss_swap(shp, &rss, &swp);
1339
1340 #if BITS_PER_LONG <= 32
1341 #define SIZE_SPEC "%10lu"
1342 #else
1343 #define SIZE_SPEC "%21lu"
1344 #endif
1345
1346         seq_printf(s,
1347                    "%10d %10d  %4o " SIZE_SPEC " %5u %5u  "
1348                    "%5lu %5u %5u %5u %5u %10lu %10lu %10lu "
1349                    SIZE_SPEC " " SIZE_SPEC "\n",
1350                    shp->shm_perm.key,
1351                    shp->shm_perm.id,
1352                    shp->shm_perm.mode,
1353                    shp->shm_segsz,
1354                    shp->shm_cprid,
1355                    shp->shm_lprid,
1356                    shp->shm_nattch,
1357                    from_kuid_munged(user_ns, shp->shm_perm.uid),
1358                    from_kgid_munged(user_ns, shp->shm_perm.gid),
1359                    from_kuid_munged(user_ns, shp->shm_perm.cuid),
1360                    from_kgid_munged(user_ns, shp->shm_perm.cgid),
1361                    shp->shm_atim,
1362                    shp->shm_dtim,
1363                    shp->shm_ctim,
1364                    rss * PAGE_SIZE,
1365                    swp * PAGE_SIZE);
1366
1367         return 0;
1368 }
1369 #endif