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         BUG_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         BUG_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 int 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         id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
 555         if (id < 0) {
 556                 error = id;
 557                 goto no_id;
 558         }
 559
 560         shp->shm_cprid = task_tgid_vnr(current);
 561         shp->shm_lprid = 0;
 562         shp->shm_atim = shp->shm_dtim = 0;
 563         shp->shm_ctim = get_seconds();
 564         shp->shm_segsz = size;
 565         shp->shm_nattch = 0;
 566         shp->shm_file = file;
 567         shp->shm_creator = current;
 568         list_add(&shp->shm_clist, &current->sysvshm.shm_clist);
 569
 570         /*
 571          * shmid gets reported as "inode#" in /proc/pid/maps.
 572          * proc-ps tools use this. Changing this will break them.
 573          */
 574         file_inode(file)->i_ino = shp->shm_perm.id;
 575
 576         ns->shm_tot += numpages;
 577         error = shp->shm_perm.id;
 578
 579         ipc_unlock_object(&shp->shm_perm);
 580         rcu_read_unlock();
 581         return error;
 582
 583 no_id:
 584         if (is_file_hugepages(file) && shp->mlock_user)
 585                 user_shm_unlock(size, shp->mlock_user);
 586         fput(file);
 587 no_file:
 588         ipc_rcu_putref(shp, shm_rcu_free);
 589         return error;
 590 }
 591
 592 /*
 593  * Called with shm_ids.rwsem and ipcp locked.
 594  */
 595 static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
 596 {
 597         struct shmid_kernel *shp;
 598
 599         shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 600         return security_shm_associate(shp, shmflg);
 601 }
 602
 603 /*
 604  * Called with shm_ids.rwsem and ipcp locked.
 605  */
 606 static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
 607                                 struct ipc_params *params)
 608 {
 609         struct shmid_kernel *shp;
 610
 611         shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 612         if (shp->shm_segsz < params->u.size)
 613                 return -EINVAL;
 614
 615         return 0;
 616 }
 617
 618 SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
 619 {
 620         struct ipc_namespace *ns;
 621         static const struct ipc_ops shm_ops = {
 622                 .getnew = newseg,
 623                 .associate = shm_security,
 624                 .more_checks = shm_more_checks,
 625         };
 626         struct ipc_params shm_params;
 627
 628         ns = current->nsproxy->ipc_ns;
 629
 630         shm_params.key = key;
 631         shm_params.flg = shmflg;
 632         shm_params.u.size = size;
 633
 634         return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
 635 }
 636
 637 static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
 638 {
 639         switch (version) {
 640         case IPC_64:
 641                 return copy_to_user(buf, in, sizeof(*in));
 642         case IPC_OLD:
 643             {
 644                 struct shmid_ds out;
 645
 646                 memset(&out, 0, sizeof(out));
 647                 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
 648                 out.shm_segsz   = in->shm_segsz;
 649                 out.shm_atime   = in->shm_atime;
 650                 out.shm_dtime   = in->shm_dtime;
 651                 out.shm_ctime   = in->shm_ctime;
 652                 out.shm_cpid    = in->shm_cpid;
 653                 out.shm_lpid    = in->shm_lpid;
 654                 out.shm_nattch  = in->shm_nattch;
 655
 656                 return copy_to_user(buf, &out, sizeof(out));
 657             }
 658         default:
 659                 return -EINVAL;
 660         }
 661 }
 662
 663 static inline unsigned long
 664 copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
 665 {
 666         switch (version) {
 667         case IPC_64:
 668                 if (copy_from_user(out, buf, sizeof(*out)))
 669                         return -EFAULT;
 670                 return 0;
 671         case IPC_OLD:
 672             {
 673                 struct shmid_ds tbuf_old;
 674
 675                 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
 676                         return -EFAULT;
 677
 678                 out->shm_perm.uid       = tbuf_old.shm_perm.uid;
 679                 out->shm_perm.gid       = tbuf_old.shm_perm.gid;
 680                 out->shm_perm.mode      = tbuf_old.shm_perm.mode;
 681
 682                 return 0;
 683             }
 684         default:
 685                 return -EINVAL;
 686         }
 687 }
 688
 689 static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
 690 {
 691         switch (version) {
 692         case IPC_64:
 693                 return copy_to_user(buf, in, sizeof(*in));
 694         case IPC_OLD:
 695             {
 696                 struct shminfo out;
 697
 698                 if (in->shmmax > INT_MAX)
 699                         out.shmmax = INT_MAX;
 700                 else
 701                         out.shmmax = (int)in->shmmax;
 702
 703                 out.shmmin      = in->shmmin;
 704                 out.shmmni      = in->shmmni;
 705                 out.shmseg      = in->shmseg;
 706                 out.shmall      = in->shmall;
 707
 708                 return copy_to_user(buf, &out, sizeof(out));
 709             }
 710         default:
 711                 return -EINVAL;
 712         }
 713 }
 714
 715 /*
 716  * Calculate and add used RSS and swap pages of a shm.
 717  * Called with shm_ids.rwsem held as a reader
 718  */
 719 static void shm_add_rss_swap(struct shmid_kernel *shp,
 720         unsigned long *rss_add, unsigned long *swp_add)
 721 {
 722         struct inode *inode;
 723
 724         inode = file_inode(shp->shm_file);
 725
 726         if (is_file_hugepages(shp->shm_file)) {
 727                 struct address_space *mapping = inode->i_mapping;
 728                 struct hstate *h = hstate_file(shp->shm_file);
 729                 *rss_add += pages_per_huge_page(h) * mapping->nrpages;
 730         } else {
 731 #ifdef CONFIG_SHMEM
 732                 struct shmem_inode_info *info = SHMEM_I(inode);
 733                 spin_lock(&info->lock);
 734                 *rss_add += inode->i_mapping->nrpages;
 735                 *swp_add += info->swapped;
 736                 spin_unlock(&info->lock);
 737 #else
 738                 *rss_add += inode->i_mapping->nrpages;
 739 #endif
 740         }
 741 }
 742
 743 /*
 744  * Called with shm_ids.rwsem held as a reader
 745  */
 746 static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
 747                 unsigned long *swp)
 748 {
 749         int next_id;
 750         int total, in_use;
 751
 752         *rss = 0;
 753         *swp = 0;
 754
 755         in_use = shm_ids(ns).in_use;
 756
 757         for (total = 0, next_id = 0; total < in_use; next_id++) {
 758                 struct kern_ipc_perm *ipc;
 759                 struct shmid_kernel *shp;
 760
 761                 ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
 762                 if (ipc == NULL)
 763                         continue;
 764                 shp = container_of(ipc, struct shmid_kernel, shm_perm);
 765
 766                 shm_add_rss_swap(shp, rss, swp);
 767
 768                 total++;
 769         }
 770 }
 771
 772 /*
 773  * This function handles some shmctl commands which require the rwsem
 774  * to be held in write mode.
 775  * NOTE: no locks must be held, the rwsem is taken inside this function.
 776  */
 777 static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
 778                        struct shmid_ds __user *buf, int version)
 779 {
 780         struct kern_ipc_perm *ipcp;
 781         struct shmid64_ds shmid64;
 782         struct shmid_kernel *shp;
 783         int err;
 784
 785         if (cmd == IPC_SET) {
 786                 if (copy_shmid_from_user(&shmid64, buf, version))
 787                         return -EFAULT;
 788         }
 789
 790         down_write(&shm_ids(ns).rwsem);
 791         rcu_read_lock();
 792
 793         ipcp = ipcctl_pre_down_nolock(ns, &shm_ids(ns), shmid, cmd,
 794                                       &shmid64.shm_perm, 0);
 795         if (IS_ERR(ipcp)) {
 796                 err = PTR_ERR(ipcp);
 797                 goto out_unlock1;
 798         }
 799
 800         shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 801
 802         err = security_shm_shmctl(shp, cmd);
 803         if (err)
 804                 goto out_unlock1;
 805
 806         switch (cmd) {
 807         case IPC_RMID:
 808                 ipc_lock_object(&shp->shm_perm);
 809                 /* do_shm_rmid unlocks the ipc object and rcu */
 810                 do_shm_rmid(ns, ipcp);
 811                 goto out_up;
 812         case IPC_SET:
 813                 ipc_lock_object(&shp->shm_perm);
 814                 err = ipc_update_perm(&shmid64.shm_perm, ipcp);
 815                 if (err)
 816                         goto out_unlock0;
 817                 shp->shm_ctim = get_seconds();
 818                 break;
 819         default:
 820                 err = -EINVAL;
 821                 goto out_unlock1;
 822         }
 823
 824 out_unlock0:
 825         ipc_unlock_object(&shp->shm_perm);
 826 out_unlock1:
 827         rcu_read_unlock();
 828 out_up:
 829         up_write(&shm_ids(ns).rwsem);
 830         return err;
 831 }
 832
 833 static int shmctl_nolock(struct ipc_namespace *ns, int shmid,
 834                          int cmd, int version, void __user *buf)
 835 {
 836         int err;
 837         struct shmid_kernel *shp;
 838
 839         /* preliminary security checks for *_INFO */
 840         if (cmd == IPC_INFO || cmd == SHM_INFO) {
 841                 err = security_shm_shmctl(NULL, cmd);
 842                 if (err)
 843                         return err;
 844         }
 845
 846         switch (cmd) {
 847         case IPC_INFO:
 848         {
 849                 struct shminfo64 shminfo;
 850
 851                 memset(&shminfo, 0, sizeof(shminfo));
 852                 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
 853                 shminfo.shmmax = ns->shm_ctlmax;
 854                 shminfo.shmall = ns->shm_ctlall;
 855
 856                 shminfo.shmmin = SHMMIN;
 857                 if (copy_shminfo_to_user(buf, &shminfo, version))
 858                         return -EFAULT;
 859
 860                 down_read(&shm_ids(ns).rwsem);
 861                 err = ipc_get_maxid(&shm_ids(ns));
 862                 up_read(&shm_ids(ns).rwsem);
 863
 864                 if (err < 0)
 865                         err = 0;
 866                 goto out;
 867         }
 868         case SHM_INFO:
 869         {
 870                 struct shm_info shm_info;
 871
 872                 memset(&shm_info, 0, sizeof(shm_info));
 873                 down_read(&shm_ids(ns).rwsem);
 874                 shm_info.used_ids = shm_ids(ns).in_use;
 875                 shm_get_stat(ns, &shm_info.shm_rss, &shm_info.shm_swp);
 876                 shm_info.shm_tot = ns->shm_tot;
 877                 shm_info.swap_attempts = 0;
 878                 shm_info.swap_successes = 0;
 879                 err = ipc_get_maxid(&shm_ids(ns));
 880                 up_read(&shm_ids(ns).rwsem);
 881                 if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {
 882                         err = -EFAULT;
 883                         goto out;
 884                 }
 885
 886                 err = err < 0 ? 0 : err;
 887                 goto out;
 888         }
 889         case SHM_STAT:
 890         case IPC_STAT:
 891         {
 892                 struct shmid64_ds tbuf;
 893                 int result;
 894
 895                 rcu_read_lock();
 896                 if (cmd == SHM_STAT) {
 897                         shp = shm_obtain_object(ns, shmid);
 898                         if (IS_ERR(shp)) {
 899                                 err = PTR_ERR(shp);
 900                                 goto out_unlock;
 901                         }
 902                         result = shp->shm_perm.id;
 903                 } else {
 904                         shp = shm_obtain_object_check(ns, shmid);
 905                         if (IS_ERR(shp)) {
 906                                 err = PTR_ERR(shp);
 907                                 goto out_unlock;
 908                         }
 909                         result = 0;
 910                 }
 911
 912                 err = -EACCES;
 913                 if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
 914                         goto out_unlock;
 915
 916                 err = security_shm_shmctl(shp, cmd);
 917                 if (err)
 918                         goto out_unlock;
 919
 920                 memset(&tbuf, 0, sizeof(tbuf));
 921                 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
 922                 tbuf.shm_segsz  = shp->shm_segsz;
 923                 tbuf.shm_atime  = shp->shm_atim;
 924                 tbuf.shm_dtime  = shp->shm_dtim;
 925                 tbuf.shm_ctime  = shp->shm_ctim;
 926                 tbuf.shm_cpid   = shp->shm_cprid;
 927                 tbuf.shm_lpid   = shp->shm_lprid;
 928                 tbuf.shm_nattch = shp->shm_nattch;
 929                 rcu_read_unlock();
 930
 931                 if (copy_shmid_to_user(buf, &tbuf, version))
 932                         err = -EFAULT;
 933                 else
 934                         err = result;
 935                 goto out;
 936         }
 937         default:
 938                 return -EINVAL;
 939         }
 940
 941 out_unlock:
 942         rcu_read_unlock();
 943 out:
 944         return err;
 945 }
 946
 947 SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 948 {
 949         struct shmid_kernel *shp;
 950         int err, version;
 951         struct ipc_namespace *ns;
 952
 953         if (cmd < 0 || shmid < 0)
 954                 return -EINVAL;
 955
 956         version = ipc_parse_version(&cmd);
 957         ns = current->nsproxy->ipc_ns;
 958
 959         switch (cmd) {
 960         case IPC_INFO:
 961         case SHM_INFO:
 962         case SHM_STAT:
 963         case IPC_STAT:
 964                 return shmctl_nolock(ns, shmid, cmd, version, buf);
 965         case IPC_RMID:
 966         case IPC_SET:
 967                 return shmctl_down(ns, shmid, cmd, buf, version);
 968         case SHM_LOCK:
 969         case SHM_UNLOCK:
 970         {
 971                 struct file *shm_file;
 972
 973                 rcu_read_lock();
 974                 shp = shm_obtain_object_check(ns, shmid);
 975                 if (IS_ERR(shp)) {
 976                         err = PTR_ERR(shp);
 977                         goto out_unlock1;
 978                 }
 979
 980                 audit_ipc_obj(&(shp->shm_perm));
 981                 err = security_shm_shmctl(shp, cmd);
 982                 if (err)
 983                         goto out_unlock1;
 984
 985                 ipc_lock_object(&shp->shm_perm);
 986
 987                 /* check if shm_destroy() is tearing down shp */
 988                 if (!ipc_valid_object(&shp->shm_perm)) {
 989                         err = -EIDRM;
 990                         goto out_unlock0;
 991                 }
 992
 993                 if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
 994                         kuid_t euid = current_euid();
 995                         if (!uid_eq(euid, shp->shm_perm.uid) &&
 996                             !uid_eq(euid, shp->shm_perm.cuid)) {
 997                                 err = -EPERM;
 998                                 goto out_unlock0;
 999                         }
1000                         if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) {
1001                                 err = -EPERM;
1002                                 goto out_unlock0;
1003                         }
1004                 }
1005
1006                 shm_file = shp->shm_file;
1007                 if (is_file_hugepages(shm_file))
1008                         goto out_unlock0;
1009
1010                 if (cmd == SHM_LOCK) {
1011                         struct user_struct *user = current_user();
1012                         err = shmem_lock(shm_file, 1, user);
1013                         if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
1014                                 shp->shm_perm.mode |= SHM_LOCKED;
1015                                 shp->mlock_user = user;
1016                         }
1017                         goto out_unlock0;
1018                 }
1019
1020                 /* SHM_UNLOCK */
1021                 if (!(shp->shm_perm.mode & SHM_LOCKED))
1022                         goto out_unlock0;
1023                 shmem_lock(shm_file, 0, shp->mlock_user);
1024                 shp->shm_perm.mode &= ~SHM_LOCKED;
1025                 shp->mlock_user = NULL;
1026                 get_file(shm_file);
1027                 ipc_unlock_object(&shp->shm_perm);
1028                 rcu_read_unlock();
1029                 shmem_unlock_mapping(shm_file->f_mapping);
1030
1031                 fput(shm_file);
1032                 return err;
1033         }
1034         default:
1035                 return -EINVAL;
1036         }
1037
1038 out_unlock0:
1039         ipc_unlock_object(&shp->shm_perm);
1040 out_unlock1:
1041         rcu_read_unlock();
1042         return err;
1043 }
1044
1045 /*
1046  * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
1047  *
1048  * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
1049  * "raddr" thing points to kernel space, and there has to be a wrapper around
1050  * this.
1051  */
1052 long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
1053               unsigned long shmlba)
1054 {
1055         struct shmid_kernel *shp;
1056         unsigned long addr;
1057         unsigned long size;
1058         struct file *file;
1059         int    err;
1060         unsigned long flags;
1061         unsigned long prot;
1062         int acc_mode;
1063         struct ipc_namespace *ns;
1064         struct shm_file_data *sfd;
1065         struct path path;
1066         fmode_t f_mode;
1067         unsigned long populate = 0;
1068
1069         err = -EINVAL;
1070         if (shmid < 0)
1071                 goto out;
1072         else if ((addr = (ulong)shmaddr)) {
1073                 if (addr & (shmlba - 1)) {
1074                         if (shmflg & SHM_RND)
1075                                 addr &= ~(shmlba - 1);     /* round down */
1076                         else
1077 #ifndef __ARCH_FORCE_SHMLBA
1078                                 if (addr & ~PAGE_MASK)
1079 #endif
1080                                         goto out;
1081                 }
1082                 flags = MAP_SHARED | MAP_FIXED;
1083         } else {
1084                 if ((shmflg & SHM_REMAP))
1085                         goto out;
1086
1087                 flags = MAP_SHARED;
1088         }
1089
1090         if (shmflg & SHM_RDONLY) {
1091                 prot = PROT_READ;
1092                 acc_mode = S_IRUGO;
1093                 f_mode = FMODE_READ;
1094         } else {
1095                 prot = PROT_READ | PROT_WRITE;
1096                 acc_mode = S_IRUGO | S_IWUGO;
1097                 f_mode = FMODE_READ | FMODE_WRITE;
1098         }
1099         if (shmflg & SHM_EXEC) {
1100                 prot |= PROT_EXEC;
1101                 acc_mode |= S_IXUGO;
1102         }
1103
1104         /*
1105          * We cannot rely on the fs check since SYSV IPC does have an
1106          * additional creator id...
1107          */
1108         ns = current->nsproxy->ipc_ns;
1109         rcu_read_lock();
1110         shp = shm_obtain_object_check(ns, shmid);
1111         if (IS_ERR(shp)) {
1112                 err = PTR_ERR(shp);
1113                 goto out_unlock;
1114         }
1115
1116         err = -EACCES;
1117         if (ipcperms(ns, &shp->shm_perm, acc_mode))
1118                 goto out_unlock;
1119
1120         err = security_shm_shmat(shp, shmaddr, shmflg);
1121         if (err)
1122                 goto out_unlock;
1123
1124         ipc_lock_object(&shp->shm_perm);
1125
1126         /* check if shm_destroy() is tearing down shp */
1127         if (!ipc_valid_object(&shp->shm_perm)) {
1128                 ipc_unlock_object(&shp->shm_perm);
1129                 err = -EIDRM;
1130                 goto out_unlock;
1131         }
1132
1133         path = shp->shm_file->f_path;
1134         path_get(&path);
1135         shp->shm_nattch++;
1136         size = i_size_read(d_inode(path.dentry));
1137         ipc_unlock_object(&shp->shm_perm);
1138         rcu_read_unlock();
1139
1140         err = -ENOMEM;
1141         sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
1142         if (!sfd) {
1143                 path_put(&path);
1144                 goto out_nattch;
1145         }
1146
1147         file = alloc_file(&path, f_mode,
1148                           is_file_hugepages(shp->shm_file) ?
1149                                 &shm_file_operations_huge :
1150                                 &shm_file_operations);
1151         err = PTR_ERR(file);
1152         if (IS_ERR(file)) {
1153                 kfree(sfd);
1154                 path_put(&path);
1155                 goto out_nattch;
1156         }
1157
1158         file->private_data = sfd;
1159         file->f_mapping = shp->shm_file->f_mapping;
1160         sfd->id = shp->shm_perm.id;
1161         sfd->ns = get_ipc_ns(ns);
1162         sfd->file = shp->shm_file;
1163         sfd->vm_ops = NULL;
1164
1165         err = security_mmap_file(file, prot, flags);
1166         if (err)
1167                 goto out_fput;
1168
1169         down_write(&current->mm->mmap_sem);
1170         if (addr && !(shmflg & SHM_REMAP)) {
1171                 err = -EINVAL;
1172                 if (addr + size < addr)
1173                         goto invalid;
1174
1175                 if (find_vma_intersection(current->mm, addr, addr + size))
1176                         goto invalid;
1177         }
1178
1179         addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate);
1180         *raddr = addr;
1181         err = 0;
1182         if (IS_ERR_VALUE(addr))
1183                 err = (long)addr;
1184 invalid:
1185         up_write(&current->mm->mmap_sem);
1186         if (populate)
1187                 mm_populate(addr, populate);
1188
1189 out_fput:
1190         fput(file);
1191
1192 out_nattch:
1193         down_write(&shm_ids(ns).rwsem);
1194         shp = shm_lock(ns, shmid);
1195         shp->shm_nattch--;
1196         if (shm_may_destroy(ns, shp))
1197                 shm_destroy(ns, shp);
1198         else
1199                 shm_unlock(shp);
1200         up_write(&shm_ids(ns).rwsem);
1201         return err;
1202
1203 out_unlock:
1204         rcu_read_unlock();
1205 out:
1206         return err;
1207 }
1208
1209 SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
1210 {
1211         unsigned long ret;
1212         long err;
1213
1214         err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
1215         if (err)
1216                 return err;
1217         force_successful_syscall_return();
1218         return (long)ret;
1219 }
1220
1221 /*
1222  * detach and kill segment if marked destroyed.
1223  * The work is done in shm_close.
1224  */
1225 SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
1226 {
1227         struct mm_struct *mm = current->mm;
1228         struct vm_area_struct *vma;
1229         unsigned long addr = (unsigned long)shmaddr;
1230         int retval = -EINVAL;
1231 #ifdef CONFIG_MMU
1232         loff_t size = 0;
1233         struct file *file;
1234         struct vm_area_struct *next;
1235 #endif
1236
1237         if (addr & ~PAGE_MASK)
1238                 return retval;
1239
1240         down_write(&mm->mmap_sem);
1241
1242         /*
1243          * This function tries to be smart and unmap shm segments that
1244          * were modified by partial mlock or munmap calls:
1245          * - It first determines the size of the shm segment that should be
1246          *   unmapped: It searches for a vma that is backed by shm and that
1247          *   started at address shmaddr. It records it's size and then unmaps
1248          *   it.
1249          * - Then it unmaps all shm vmas that started at shmaddr and that
1250          *   are within the initially determined size and that are from the
1251          *   same shm segment from which we determined the size.
1252          * Errors from do_munmap are ignored: the function only fails if
1253          * it's called with invalid parameters or if it's called to unmap
1254          * a part of a vma. Both calls in this function are for full vmas,
1255          * the parameters are directly copied from the vma itself and always
1256          * valid - therefore do_munmap cannot fail. (famous last words?)
1257          */
1258         /*
1259          * If it had been mremap()'d, the starting address would not
1260          * match the usual checks anyway. So assume all vma's are
1261          * above the starting address given.
1262          */
1263         vma = find_vma(mm, addr);
1264
1265 #ifdef CONFIG_MMU
1266         while (vma) {
1267                 next = vma->vm_next;
1268
1269                 /*
1270                  * Check if the starting address would match, i.e. it's
1271                  * a fragment created by mprotect() and/or munmap(), or it
1272                  * otherwise it starts at this address with no hassles.
1273                  */
1274                 if ((vma->vm_ops == &shm_vm_ops) &&
1275                         (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
1276
1277                         /*
1278                          * Record the file of the shm segment being
1279                          * unmapped.  With mremap(), someone could place
1280                          * page from another segment but with equal offsets
1281                          * in the range we are unmapping.
1282                          */
1283                         file = vma->vm_file;
1284                         size = i_size_read(file_inode(vma->vm_file));
1285                         do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1286                         /*
1287                          * We discovered the size of the shm segment, so
1288                          * break out of here and fall through to the next
1289                          * loop that uses the size information to stop
1290                          * searching for matching vma's.
1291                          */
1292                         retval = 0;
1293                         vma = next;
1294                         break;
1295                 }
1296                 vma = next;
1297         }
1298
1299         /*
1300          * We need look no further than the maximum address a fragment
1301          * could possibly have landed at. Also cast things to loff_t to
1302          * prevent overflows and make comparisons vs. equal-width types.
1303          */
1304         size = PAGE_ALIGN(size);
1305         while (vma && (loff_t)(vma->vm_end - addr) <= size) {
1306                 next = vma->vm_next;
1307
1308                 /* finding a matching vma now does not alter retval */
1309                 if ((vma->vm_ops == &shm_vm_ops) &&
1310                     ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) &&
1311                     (vma->vm_file == file))
1312                         do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1313                 vma = next;
1314         }
1315
1316 #else /* CONFIG_MMU */
1317         /* under NOMMU conditions, the exact address to be destroyed must be
1318          * given */
1319         if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
1320                 do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1321                 retval = 0;
1322         }
1323
1324 #endif
1325
1326         up_write(&mm->mmap_sem);
1327         return retval;
1328 }
1329
1330 #ifdef CONFIG_PROC_FS
1331 static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
1332 {
1333         struct user_namespace *user_ns = seq_user_ns(s);
1334         struct shmid_kernel *shp = it;
1335         unsigned long rss = 0, swp = 0;
1336
1337         shm_add_rss_swap(shp, &rss, &swp);
1338
1339 #if BITS_PER_LONG <= 32
1340 #define SIZE_SPEC "%10lu"
1341 #else
1342 #define SIZE_SPEC "%21lu"
1343 #endif
1344
1345         seq_printf(s,
1346                    "%10d %10d  %4o " SIZE_SPEC " %5u %5u  "
1347                    "%5lu %5u %5u %5u %5u %10lu %10lu %10lu "
1348                    SIZE_SPEC " " SIZE_SPEC "\n",
1349                    shp->shm_perm.key,
1350                    shp->shm_perm.id,
1351                    shp->shm_perm.mode,
1352                    shp->shm_segsz,
1353                    shp->shm_cprid,
1354                    shp->shm_lprid,
1355                    shp->shm_nattch,
1356                    from_kuid_munged(user_ns, shp->shm_perm.uid),
1357                    from_kgid_munged(user_ns, shp->shm_perm.gid),
1358                    from_kuid_munged(user_ns, shp->shm_perm.cuid),
1359                    from_kgid_munged(user_ns, shp->shm_perm.cgid),
1360                    shp->shm_atim,
1361                    shp->shm_dtim,
1362                    shp->shm_ctim,
1363                    rss * PAGE_SIZE,
1364                    swp * PAGE_SIZE);
1365
1366         return 0;
1367 }
1368 #endif