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(&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         if (IS_ERR(ipcp))
 159                 return (struct shmid_kernel *)ipcp;
 160
 161         return container_of(ipcp, struct shmid_kernel, shm_perm);
 162 }
 163
 164 static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
 165 {
 166         rcu_read_lock();
 167         ipc_lock_object(&ipcp->shm_perm);
 168 }
 169
 170 static void shm_rcu_free(struct rcu_head *head)
 171 {
 172         struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
 173         struct shmid_kernel *shp = ipc_rcu_to_struct(p);
 174
 175         security_shm_free(shp);
 176         ipc_rcu_free(head);
 177 }
 178
 179 static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
 180 {
 181         list_del(&s->shm_clist);
 182         ipc_rmid(&shm_ids(ns), &s->shm_perm);
 183 }
 184
 185
 186 /* This is called by fork, once for every shm attach. */
 187 static void shm_open(struct vm_area_struct *vma)
 188 {
 189         struct file *file = vma->vm_file;
 190         struct shm_file_data *sfd = shm_file_data(file);
 191         struct shmid_kernel *shp;
 192
 193         shp = shm_lock(sfd->ns, sfd->id);
 194         BUG_ON(IS_ERR(shp));
 195         shp->shm_atim = get_seconds();
 196         shp->shm_lprid = task_tgid_vnr(current);
 197         shp->shm_nattch++;
 198         shm_unlock(shp);
 199 }
 200
 201 /*
 202  * shm_destroy - free the struct shmid_kernel
 203  *
 204  * @ns: namespace
 205  * @shp: struct to free
 206  *
 207  * It has to be called with shp and shm_ids.rwsem (writer) locked,
 208  * but returns with shp unlocked and freed.
 209  */
 210 static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
 211 {
 212         struct file *shm_file;
 213
 214         shm_file = shp->shm_file;
 215         shp->shm_file = NULL;
 216         ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
 217         shm_rmid(ns, shp);
 218         shm_unlock(shp);
 219         if (!is_file_hugepages(shm_file))
 220                 shmem_lock(shm_file, 0, shp->mlock_user);
 221         else if (shp->mlock_user)
 222                 user_shm_unlock(i_size_read(file_inode(shm_file)),
 223                                 shp->mlock_user);
 224         fput(shm_file);
 225         ipc_rcu_putref(shp, shm_rcu_free);
 226 }
 227
 228 /*
 229  * shm_may_destroy - identifies whether shm segment should be destroyed now
 230  *
 231  * Returns true if and only if there are no active users of the segment and
 232  * one of the following is true:
 233  *
 234  * 1) shmctl(id, IPC_RMID, NULL) was called for this shp
 235  *
 236  * 2) sysctl kernel.shm_rmid_forced is set to 1.
 237  */
 238 static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
 239 {
 240         return (shp->shm_nattch == 0) &&
 241                (ns->shm_rmid_forced ||
 242                 (shp->shm_perm.mode & SHM_DEST));
 243 }
 244
 245 /*
 246  * remove the attach descriptor vma.
 247  * free memory for segment if it is marked destroyed.
 248  * The descriptor has already been removed from the current->mm->mmap list
 249  * and will later be kfree()d.
 250  */
 251 static void shm_close(struct vm_area_struct *vma)
 252 {
 253         struct file *file = vma->vm_file;
 254         struct shm_file_data *sfd = shm_file_data(file);
 255         struct shmid_kernel *shp;
 256         struct ipc_namespace *ns = sfd->ns;
 257
 258         down_write(&shm_ids(ns).rwsem);
 259         /* remove from the list of attaches of the shm segment */
 260         shp = shm_lock(ns, sfd->id);
 261         BUG_ON(IS_ERR(shp));
 262         shp->shm_lprid = task_tgid_vnr(current);
 263         shp->shm_dtim = get_seconds();
 264         shp->shm_nattch--;
 265         if (shm_may_destroy(ns, shp))
 266                 shm_destroy(ns, shp);
 267         else
 268                 shm_unlock(shp);
 269         up_write(&shm_ids(ns).rwsem);
 270 }
 271
 272 /* Called with ns->shm_ids(ns).rwsem locked */
 273 static int shm_try_destroy_orphaned(int id, void *p, void *data)
 274 {
 275         struct ipc_namespace *ns = data;
 276         struct kern_ipc_perm *ipcp = p;
 277         struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 278
 279         /*
 280          * We want to destroy segments without users and with already
 281          * exit'ed originating process.
 282          *
 283          * As shp->* are changed under rwsem, it's safe to skip shp locking.
 284          */
 285         if (shp->shm_creator != NULL)
 286                 return 0;
 287
 288         if (shm_may_destroy(ns, shp)) {
 289                 shm_lock_by_ptr(shp);
 290                 shm_destroy(ns, shp);
 291         }
 292         return 0;
 293 }
 294
 295 void shm_destroy_orphaned(struct ipc_namespace *ns)
 296 {
 297         down_write(&shm_ids(ns).rwsem);
 298         if (shm_ids(ns).in_use)
 299                 idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
 300         up_write(&shm_ids(ns).rwsem);
 301 }
 302
 303 /* Locking assumes this will only be called with task == current */
 304 void exit_shm(struct task_struct *task)
 305 {
 306         struct ipc_namespace *ns = task->nsproxy->ipc_ns;
 307         struct shmid_kernel *shp, *n;
 308
 309         if (list_empty(&task->sysvshm.shm_clist))
 310                 return;
 311
 312         /*
 313          * If kernel.shm_rmid_forced is not set then only keep track of
 314          * which shmids are orphaned, so that a later set of the sysctl
 315          * can clean them up.
 316          */
 317         if (!ns->shm_rmid_forced) {
 318                 down_read(&shm_ids(ns).rwsem);
 319                 list_for_each_entry(shp, &task->sysvshm.shm_clist, shm_clist)
 320                         shp->shm_creator = NULL;
 321                 /*
 322                  * Only under read lock but we are only called on current
 323                  * so no entry on the list will be shared.
 324                  */
 325                 list_del(&task->sysvshm.shm_clist);
 326                 up_read(&shm_ids(ns).rwsem);
 327                 return;
 328         }
 329
 330         /*
 331          * Destroy all already created segments, that were not yet mapped,
 332          * and mark any mapped as orphan to cover the sysctl toggling.
 333          * Destroy is skipped if shm_may_destroy() returns false.
 334          */
 335         down_write(&shm_ids(ns).rwsem);
 336         list_for_each_entry_safe(shp, n, &task->sysvshm.shm_clist, shm_clist) {
 337                 shp->shm_creator = NULL;
 338
 339                 if (shm_may_destroy(ns, shp)) {
 340                         shm_lock_by_ptr(shp);
 341                         shm_destroy(ns, shp);
 342                 }
 343         }
 344
 345         /* Remove the list head from any segments still attached. */
 346         list_del(&task->sysvshm.shm_clist);
 347         up_write(&shm_ids(ns).rwsem);
 348 }
 349
 350 static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 351 {
 352         struct file *file = vma->vm_file;
 353         struct shm_file_data *sfd = shm_file_data(file);
 354
 355         return sfd->vm_ops->fault(vma, vmf);
 356 }
 357
 358 #ifdef CONFIG_NUMA
 359 static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
 360 {
 361         struct file *file = vma->vm_file;
 362         struct shm_file_data *sfd = shm_file_data(file);
 363         int err = 0;
 364         if (sfd->vm_ops->set_policy)
 365                 err = sfd->vm_ops->set_policy(vma, new);
 366         return err;
 367 }
 368
 369 static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
 370                                         unsigned long addr)
 371 {
 372         struct file *file = vma->vm_file;
 373         struct shm_file_data *sfd = shm_file_data(file);
 374         struct mempolicy *pol = NULL;
 375
 376         if (sfd->vm_ops->get_policy)
 377                 pol = sfd->vm_ops->get_policy(vma, addr);
 378         else if (vma->vm_policy)
 379                 pol = vma->vm_policy;
 380
 381         return pol;
 382 }
 383 #endif
 384
 385 static int shm_mmap(struct file *file, struct vm_area_struct *vma)
 386 {
 387         struct shm_file_data *sfd = shm_file_data(file);
 388         int ret;
 389
 390         ret = sfd->file->f_op->mmap(sfd->file, vma);
 391         if (ret != 0)
 392                 return ret;
 393         sfd->vm_ops = vma->vm_ops;
 394 #ifdef CONFIG_MMU
 395         BUG_ON(!sfd->vm_ops->fault);
 396 #endif
 397         vma->vm_ops = &shm_vm_ops;
 398         shm_open(vma);
 399
 400         return ret;
 401 }
 402
 403 static int shm_release(struct inode *ino, struct file *file)
 404 {
 405         struct shm_file_data *sfd = shm_file_data(file);
 406
 407         put_ipc_ns(sfd->ns);
 408         shm_file_data(file) = NULL;
 409         kfree(sfd);
 410         return 0;
 411 }
 412
 413 static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 414 {
 415         struct shm_file_data *sfd = shm_file_data(file);
 416
 417         if (!sfd->file->f_op->fsync)
 418                 return -EINVAL;
 419         return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
 420 }
 421
 422 static long shm_fallocate(struct file *file, int mode, loff_t offset,
 423                           loff_t len)
 424 {
 425         struct shm_file_data *sfd = shm_file_data(file);
 426
 427         if (!sfd->file->f_op->fallocate)
 428                 return -EOPNOTSUPP;
 429         return sfd->file->f_op->fallocate(file, mode, offset, len);
 430 }
 431
 432 static unsigned long shm_get_unmapped_area(struct file *file,
 433         unsigned long addr, unsigned long len, unsigned long pgoff,
 434         unsigned long flags)
 435 {
 436         struct shm_file_data *sfd = shm_file_data(file);
 437         return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
 438                                                 pgoff, flags);
 439 }
 440
 441 static const struct file_operations shm_file_operations = {
 442         .mmap           = shm_mmap,
 443         .fsync          = shm_fsync,
 444         .release        = shm_release,
 445 #ifndef CONFIG_MMU
 446         .get_unmapped_area      = shm_get_unmapped_area,
 447 #endif
 448         .llseek         = noop_llseek,
 449         .fallocate      = shm_fallocate,
 450 };
 451
 452 static const struct file_operations shm_file_operations_huge = {
 453         .mmap           = shm_mmap,
 454         .fsync          = shm_fsync,
 455         .release        = shm_release,
 456         .get_unmapped_area      = shm_get_unmapped_area,
 457         .llseek         = noop_llseek,
 458         .fallocate      = shm_fallocate,
 459 };
 460
 461 int is_file_shm_hugepages(struct file *file)
 462 {
 463         return file->f_op == &shm_file_operations_huge;
 464 }
 465
 466 static const struct vm_operations_struct shm_vm_ops = {
 467         .open   = shm_open,     /* callback for a new vm-area open */
 468         .close  = shm_close,    /* callback for when the vm-area is released */
 469         .fault  = shm_fault,
 470 #if defined(CONFIG_NUMA)
 471         .set_policy = shm_set_policy,
 472         .get_policy = shm_get_policy,
 473 #endif
 474 };
 475
 476 /**
 477  * newseg - Create a new shared memory segment
 478  * @ns: namespace
 479  * @params: ptr to the structure that contains key, size and shmflg
 480  *
 481  * Called with shm_ids.rwsem held as a writer.
 482  */
 483 static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
 484 {
 485         key_t key = params->key;
 486         int shmflg = params->flg;
 487         size_t size = params->u.size;
 488         int error;
 489         struct shmid_kernel *shp;
 490         size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 491         struct file *file;
 492         char name[13];
 493         int id;
 494         vm_flags_t acctflag = 0;
 495
 496         if (size < SHMMIN || size > ns->shm_ctlmax)
 497                 return -EINVAL;
 498
 499         if (numpages << PAGE_SHIFT < size)
 500                 return -ENOSPC;
 501
 502         if (ns->shm_tot + numpages < ns->shm_tot ||
 503                         ns->shm_tot + numpages > ns->shm_ctlall)
 504                 return -ENOSPC;
 505
 506         shp = ipc_rcu_alloc(sizeof(*shp));
 507         if (!shp)
 508                 return -ENOMEM;
 509
 510         shp->shm_perm.key = key;
 511         shp->shm_perm.mode = (shmflg & S_IRWXUGO);
 512         shp->mlock_user = NULL;
 513
 514         shp->shm_perm.security = NULL;
 515         error = security_shm_alloc(shp);
 516         if (error) {
 517                 ipc_rcu_putref(shp, ipc_rcu_free);
 518                 return error;
 519         }
 520
 521         sprintf(name, "SYSV%08x", key);
 522         if (shmflg & SHM_HUGETLB) {
 523                 struct hstate *hs;
 524                 size_t hugesize;
 525
 526                 hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
 527                 if (!hs) {
 528                         error = -EINVAL;
 529                         goto no_file;
 530                 }
 531                 hugesize = ALIGN(size, huge_page_size(hs));
 532
 533                 /* hugetlb_file_setup applies strict accounting */
 534                 if (shmflg & SHM_NORESERVE)
 535                         acctflag = VM_NORESERVE;
 536                 file = hugetlb_file_setup(name, hugesize, acctflag,
 537                                   &shp->mlock_user, HUGETLB_SHMFS_INODE,
 538                                 (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
 539         } else {
 540                 /*
 541                  * Do not allow no accounting for OVERCOMMIT_NEVER, even
 542                  * if it's asked for.
 543                  */
 544                 if  ((shmflg & SHM_NORESERVE) &&
 545                                 sysctl_overcommit_memory != OVERCOMMIT_NEVER)
 546                         acctflag = VM_NORESERVE;
 547                 file = shmem_file_setup(name, size, acctflag);
 548         }
 549         error = PTR_ERR(file);
 550         if (IS_ERR(file))
 551                 goto no_file;
 552
 553         id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
 554         if (id < 0) {
 555                 error = id;
 556                 goto no_id;
 557         }
 558
 559         shp->shm_cprid = task_tgid_vnr(current);
 560         shp->shm_lprid = 0;
 561         shp->shm_atim = shp->shm_dtim = 0;
 562         shp->shm_ctim = get_seconds();
 563         shp->shm_segsz = size;
 564         shp->shm_nattch = 0;
 565         shp->shm_file = file;
 566         shp->shm_creator = current;
 567         list_add(&shp->shm_clist, &current->sysvshm.shm_clist);
 568
 569         /*
 570          * shmid gets reported as "inode#" in /proc/pid/maps.
 571          * proc-ps tools use this. Changing this will break them.
 572          */
 573         file_inode(file)->i_ino = shp->shm_perm.id;
 574
 575         ns->shm_tot += numpages;
 576         error = shp->shm_perm.id;
 577
 578         ipc_unlock_object(&shp->shm_perm);
 579         rcu_read_unlock();
 580         return error;
 581
 582 no_id:
 583         if (is_file_hugepages(file) && shp->mlock_user)
 584                 user_shm_unlock(size, shp->mlock_user);
 585         fput(file);
 586 no_file:
 587         ipc_rcu_putref(shp, shm_rcu_free);
 588         return error;
 589 }
 590
 591 /*
 592  * Called with shm_ids.rwsem and ipcp locked.
 593  */
 594 static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
 595 {
 596         struct shmid_kernel *shp;
 597
 598         shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 599         return security_shm_associate(shp, shmflg);
 600 }
 601
 602 /*
 603  * Called with shm_ids.rwsem and ipcp locked.
 604  */
 605 static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
 606                                 struct ipc_params *params)
 607 {
 608         struct shmid_kernel *shp;
 609
 610         shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 611         if (shp->shm_segsz < params->u.size)
 612                 return -EINVAL;
 613
 614         return 0;
 615 }
 616
 617 SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
 618 {
 619         struct ipc_namespace *ns;
 620         static const struct ipc_ops shm_ops = {
 621                 .getnew = newseg,
 622                 .associate = shm_security,
 623                 .more_checks = shm_more_checks,
 624         };
 625         struct ipc_params shm_params;
 626
 627         ns = current->nsproxy->ipc_ns;
 628
 629         shm_params.key = key;
 630         shm_params.flg = shmflg;
 631         shm_params.u.size = size;
 632
 633         return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
 634 }
 635
 636 static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
 637 {
 638         switch (version) {
 639         case IPC_64:
 640                 return copy_to_user(buf, in, sizeof(*in));
 641         case IPC_OLD:
 642             {
 643                 struct shmid_ds out;
 644
 645                 memset(&out, 0, sizeof(out));
 646                 ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
 647                 out.shm_segsz   = in->shm_segsz;
 648                 out.shm_atime   = in->shm_atime;
 649                 out.shm_dtime   = in->shm_dtime;
 650                 out.shm_ctime   = in->shm_ctime;
 651                 out.shm_cpid    = in->shm_cpid;
 652                 out.shm_lpid    = in->shm_lpid;
 653                 out.shm_nattch  = in->shm_nattch;
 654
 655                 return copy_to_user(buf, &out, sizeof(out));
 656             }
 657         default:
 658                 return -EINVAL;
 659         }
 660 }
 661
 662 static inline unsigned long
 663 copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
 664 {
 665         switch (version) {
 666         case IPC_64:
 667                 if (copy_from_user(out, buf, sizeof(*out)))
 668                         return -EFAULT;
 669                 return 0;
 670         case IPC_OLD:
 671             {
 672                 struct shmid_ds tbuf_old;
 673
 674                 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
 675                         return -EFAULT;
 676
 677                 out->shm_perm.uid       = tbuf_old.shm_perm.uid;
 678                 out->shm_perm.gid       = tbuf_old.shm_perm.gid;
 679                 out->shm_perm.mode      = tbuf_old.shm_perm.mode;
 680
 681                 return 0;
 682             }
 683         default:
 684                 return -EINVAL;
 685         }
 686 }
 687
 688 static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
 689 {
 690         switch (version) {
 691         case IPC_64:
 692                 return copy_to_user(buf, in, sizeof(*in));
 693         case IPC_OLD:
 694             {
 695                 struct shminfo out;
 696
 697                 if (in->shmmax > INT_MAX)
 698                         out.shmmax = INT_MAX;
 699                 else
 700                         out.shmmax = (int)in->shmmax;
 701
 702                 out.shmmin      = in->shmmin;
 703                 out.shmmni      = in->shmmni;
 704                 out.shmseg      = in->shmseg;
 705                 out.shmall      = in->shmall;
 706
 707                 return copy_to_user(buf, &out, sizeof(out));
 708             }
 709         default:
 710                 return -EINVAL;
 711         }
 712 }
 713
 714 /*
 715  * Calculate and add used RSS and swap pages of a shm.
 716  * Called with shm_ids.rwsem held as a reader
 717  */
 718 static void shm_add_rss_swap(struct shmid_kernel *shp,
 719         unsigned long *rss_add, unsigned long *swp_add)
 720 {
 721         struct inode *inode;
 722
 723         inode = file_inode(shp->shm_file);
 724
 725         if (is_file_hugepages(shp->shm_file)) {
 726                 struct address_space *mapping = inode->i_mapping;
 727                 struct hstate *h = hstate_file(shp->shm_file);
 728                 *rss_add += pages_per_huge_page(h) * mapping->nrpages;
 729         } else {
 730 #ifdef CONFIG_SHMEM
 731                 struct shmem_inode_info *info = SHMEM_I(inode);
 732                 spin_lock(&info->lock);
 733                 *rss_add += inode->i_mapping->nrpages;
 734                 *swp_add += info->swapped;
 735                 spin_unlock(&info->lock);
 736 #else
 737                 *rss_add += inode->i_mapping->nrpages;
 738 #endif
 739         }
 740 }
 741
 742 /*
 743  * Called with shm_ids.rwsem held as a reader
 744  */
 745 static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
 746                 unsigned long *swp)
 747 {
 748         int next_id;
 749         int total, in_use;
 750
 751         *rss = 0;
 752         *swp = 0;
 753
 754         in_use = shm_ids(ns).in_use;
 755
 756         for (total = 0, next_id = 0; total < in_use; next_id++) {
 757                 struct kern_ipc_perm *ipc;
 758                 struct shmid_kernel *shp;
 759
 760                 ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
 761                 if (ipc == NULL)
 762                         continue;
 763                 shp = container_of(ipc, struct shmid_kernel, shm_perm);
 764
 765                 shm_add_rss_swap(shp, rss, swp);
 766
 767                 total++;
 768         }
 769 }
 770
 771 /*
 772  * This function handles some shmctl commands which require the rwsem
 773  * to be held in write mode.
 774  * NOTE: no locks must be held, the rwsem is taken inside this function.
 775  */
 776 static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
 777                        struct shmid_ds __user *buf, int version)
 778 {
 779         struct kern_ipc_perm *ipcp;
 780         struct shmid64_ds shmid64;
 781         struct shmid_kernel *shp;
 782         int err;
 783
 784         if (cmd == IPC_SET) {
 785                 if (copy_shmid_from_user(&shmid64, buf, version))
 786                         return -EFAULT;
 787         }
 788
 789         down_write(&shm_ids(ns).rwsem);
 790         rcu_read_lock();
 791
 792         ipcp = ipcctl_pre_down_nolock(ns, &shm_ids(ns), shmid, cmd,
 793                                       &shmid64.shm_perm, 0);
 794         if (IS_ERR(ipcp)) {
 795                 err = PTR_ERR(ipcp);
 796                 goto out_unlock1;
 797         }
 798
 799         shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 800
 801         err = security_shm_shmctl(shp, cmd);
 802         if (err)
 803                 goto out_unlock1;
 804
 805         switch (cmd) {
 806         case IPC_RMID:
 807                 ipc_lock_object(&shp->shm_perm);
 808                 /* do_shm_rmid unlocks the ipc object and rcu */
 809                 do_shm_rmid(ns, ipcp);
 810                 goto out_up;
 811         case IPC_SET:
 812                 ipc_lock_object(&shp->shm_perm);
 813                 err = ipc_update_perm(&shmid64.shm_perm, ipcp);
 814                 if (err)
 815                         goto out_unlock0;
 816                 shp->shm_ctim = get_seconds();
 817                 break;
 818         default:
 819                 err = -EINVAL;
 820                 goto out_unlock1;
 821         }
 822
 823 out_unlock0:
 824         ipc_unlock_object(&shp->shm_perm);
 825 out_unlock1:
 826         rcu_read_unlock();
 827 out_up:
 828         up_write(&shm_ids(ns).rwsem);
 829         return err;
 830 }
 831
 832 static int shmctl_nolock(struct ipc_namespace *ns, int shmid,
 833                          int cmd, int version, void __user *buf)
 834 {
 835         int err;
 836         struct shmid_kernel *shp;
 837
 838         /* preliminary security checks for *_INFO */
 839         if (cmd == IPC_INFO || cmd == SHM_INFO) {
 840                 err = security_shm_shmctl(NULL, cmd);
 841                 if (err)
 842                         return err;
 843         }
 844
 845         switch (cmd) {
 846         case IPC_INFO:
 847         {
 848                 struct shminfo64 shminfo;
 849
 850                 memset(&shminfo, 0, sizeof(shminfo));
 851                 shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
 852                 shminfo.shmmax = ns->shm_ctlmax;
 853                 shminfo.shmall = ns->shm_ctlall;
 854
 855                 shminfo.shmmin = SHMMIN;
 856                 if (copy_shminfo_to_user(buf, &shminfo, version))
 857                         return -EFAULT;
 858
 859                 down_read(&shm_ids(ns).rwsem);
 860                 err = ipc_get_maxid(&shm_ids(ns));
 861                 up_read(&shm_ids(ns).rwsem);
 862
 863                 if (err < 0)
 864                         err = 0;
 865                 goto out;
 866         }
 867         case SHM_INFO:
 868         {
 869                 struct shm_info shm_info;
 870
 871                 memset(&shm_info, 0, sizeof(shm_info));
 872                 down_read(&shm_ids(ns).rwsem);
 873                 shm_info.used_ids = shm_ids(ns).in_use;
 874                 shm_get_stat(ns, &shm_info.shm_rss, &shm_info.shm_swp);
 875                 shm_info.shm_tot = ns->shm_tot;
 876                 shm_info.swap_attempts = 0;
 877                 shm_info.swap_successes = 0;
 878                 err = ipc_get_maxid(&shm_ids(ns));
 879                 up_read(&shm_ids(ns).rwsem);
 880                 if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {
 881                         err = -EFAULT;
 882                         goto out;
 883                 }
 884
 885                 err = err < 0 ? 0 : err;
 886                 goto out;
 887         }
 888         case SHM_STAT:
 889         case IPC_STAT:
 890         {
 891                 struct shmid64_ds tbuf;
 892                 int result;
 893
 894                 rcu_read_lock();
 895                 if (cmd == SHM_STAT) {
 896                         shp = shm_obtain_object(ns, shmid);
 897                         if (IS_ERR(shp)) {
 898                                 err = PTR_ERR(shp);
 899                                 goto out_unlock;
 900                         }
 901                         result = shp->shm_perm.id;
 902                 } else {
 903                         shp = shm_obtain_object_check(ns, shmid);
 904                         if (IS_ERR(shp)) {
 905                                 err = PTR_ERR(shp);
 906                                 goto out_unlock;
 907                         }
 908                         result = 0;
 909                 }
 910
 911                 err = -EACCES;
 912                 if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
 913                         goto out_unlock;
 914
 915                 err = security_shm_shmctl(shp, cmd);
 916                 if (err)
 917                         goto out_unlock;
 918
 919                 memset(&tbuf, 0, sizeof(tbuf));
 920                 kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
 921                 tbuf.shm_segsz  = shp->shm_segsz;
 922                 tbuf.shm_atime  = shp->shm_atim;
 923                 tbuf.shm_dtime  = shp->shm_dtim;
 924                 tbuf.shm_ctime  = shp->shm_ctim;
 925                 tbuf.shm_cpid   = shp->shm_cprid;
 926                 tbuf.shm_lpid   = shp->shm_lprid;
 927                 tbuf.shm_nattch = shp->shm_nattch;
 928                 rcu_read_unlock();
 929
 930                 if (copy_shmid_to_user(buf, &tbuf, version))
 931                         err = -EFAULT;
 932                 else
 933                         err = result;
 934                 goto out;
 935         }
 936         default:
 937                 return -EINVAL;
 938         }
 939
 940 out_unlock:
 941         rcu_read_unlock();
 942 out:
 943         return err;
 944 }
 945
 946 SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 947 {
 948         struct shmid_kernel *shp;
 949         int err, version;
 950         struct ipc_namespace *ns;
 951
 952         if (cmd < 0 || shmid < 0)
 953                 return -EINVAL;
 954
 955         version = ipc_parse_version(&cmd);
 956         ns = current->nsproxy->ipc_ns;
 957
 958         switch (cmd) {
 959         case IPC_INFO:
 960         case SHM_INFO:
 961         case SHM_STAT:
 962         case IPC_STAT:
 963                 return shmctl_nolock(ns, shmid, cmd, version, buf);
 964         case IPC_RMID:
 965         case IPC_SET:
 966                 return shmctl_down(ns, shmid, cmd, buf, version);
 967         case SHM_LOCK:
 968         case SHM_UNLOCK:
 969         {
 970                 struct file *shm_file;
 971
 972                 rcu_read_lock();
 973                 shp = shm_obtain_object_check(ns, shmid);
 974                 if (IS_ERR(shp)) {
 975                         err = PTR_ERR(shp);
 976                         goto out_unlock1;
 977                 }
 978
 979                 audit_ipc_obj(&(shp->shm_perm));
 980                 err = security_shm_shmctl(shp, cmd);
 981                 if (err)
 982                         goto out_unlock1;
 983
 984                 ipc_lock_object(&shp->shm_perm);
 985
 986                 /* check if shm_destroy() is tearing down shp */
 987                 if (!ipc_valid_object(&shp->shm_perm)) {
 988                         err = -EIDRM;
 989                         goto out_unlock0;
 990                 }
 991
 992                 if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
 993                         kuid_t euid = current_euid();
 994                         if (!uid_eq(euid, shp->shm_perm.uid) &&
 995                             !uid_eq(euid, shp->shm_perm.cuid)) {
 996                                 err = -EPERM;
 997                                 goto out_unlock0;
 998                         }
 999                         if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) {
1000                                 err = -EPERM;
1001                                 goto out_unlock0;
1002                         }
1003                 }
1004
1005                 shm_file = shp->shm_file;
1006                 if (is_file_hugepages(shm_file))
1007                         goto out_unlock0;
1008
1009                 if (cmd == SHM_LOCK) {
1010                         struct user_struct *user = current_user();
1011                         err = shmem_lock(shm_file, 1, user);
1012                         if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
1013                                 shp->shm_perm.mode |= SHM_LOCKED;
1014                                 shp->mlock_user = user;
1015                         }
1016                         goto out_unlock0;
1017                 }
1018
1019                 /* SHM_UNLOCK */
1020                 if (!(shp->shm_perm.mode & SHM_LOCKED))
1021                         goto out_unlock0;
1022                 shmem_lock(shm_file, 0, shp->mlock_user);
1023                 shp->shm_perm.mode &= ~SHM_LOCKED;
1024                 shp->mlock_user = NULL;
1025                 get_file(shm_file);
1026                 ipc_unlock_object(&shp->shm_perm);
1027                 rcu_read_unlock();
1028                 shmem_unlock_mapping(shm_file->f_mapping);
1029
1030                 fput(shm_file);
1031                 return err;
1032         }
1033         default:
1034                 return -EINVAL;
1035         }
1036
1037 out_unlock0:
1038         ipc_unlock_object(&shp->shm_perm);
1039 out_unlock1:
1040         rcu_read_unlock();
1041         return err;
1042 }
1043
1044 /*
1045  * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
1046  *
1047  * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
1048  * "raddr" thing points to kernel space, and there has to be a wrapper around
1049  * this.
1050  */
1051 long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
1052               unsigned long shmlba)
1053 {
1054         struct shmid_kernel *shp;
1055         unsigned long addr;
1056         unsigned long size;
1057         struct file *file;
1058         int    err;
1059         unsigned long flags;
1060         unsigned long prot;
1061         int acc_mode;
1062         struct ipc_namespace *ns;
1063         struct shm_file_data *sfd;
1064         struct path path;
1065         fmode_t f_mode;
1066         unsigned long populate = 0;
1067
1068         err = -EINVAL;
1069         if (shmid < 0)
1070                 goto out;
1071         else if ((addr = (ulong)shmaddr)) {
1072                 if (addr & (shmlba - 1)) {
1073                         if (shmflg & SHM_RND)
1074                                 addr &= ~(shmlba - 1);     /* round down */
1075                         else
1076 #ifndef __ARCH_FORCE_SHMLBA
1077                                 if (addr & ~PAGE_MASK)
1078 #endif
1079                                         goto out;
1080                 }
1081                 flags = MAP_SHARED | MAP_FIXED;
1082         } else {
1083                 if ((shmflg & SHM_REMAP))
1084                         goto out;
1085
1086                 flags = MAP_SHARED;
1087         }
1088
1089         if (shmflg & SHM_RDONLY) {
1090                 prot = PROT_READ;
1091                 acc_mode = S_IRUGO;
1092                 f_mode = FMODE_READ;
1093         } else {
1094                 prot = PROT_READ | PROT_WRITE;
1095                 acc_mode = S_IRUGO | S_IWUGO;
1096                 f_mode = FMODE_READ | FMODE_WRITE;
1097         }
1098         if (shmflg & SHM_EXEC) {
1099                 prot |= PROT_EXEC;
1100                 acc_mode |= S_IXUGO;
1101         }
1102
1103         /*
1104          * We cannot rely on the fs check since SYSV IPC does have an
1105          * additional creator id...
1106          */
1107         ns = current->nsproxy->ipc_ns;
1108         rcu_read_lock();
1109         shp = shm_obtain_object_check(ns, shmid);
1110         if (IS_ERR(shp)) {
1111                 err = PTR_ERR(shp);
1112                 goto out_unlock;
1113         }
1114
1115         err = -EACCES;
1116         if (ipcperms(ns, &shp->shm_perm, acc_mode))
1117                 goto out_unlock;
1118
1119         err = security_shm_shmat(shp, shmaddr, shmflg);
1120         if (err)
1121                 goto out_unlock;
1122
1123         ipc_lock_object(&shp->shm_perm);
1124
1125         /* check if shm_destroy() is tearing down shp */
1126         if (!ipc_valid_object(&shp->shm_perm)) {
1127                 ipc_unlock_object(&shp->shm_perm);
1128                 err = -EIDRM;
1129                 goto out_unlock;
1130         }
1131
1132         path = shp->shm_file->f_path;
1133         path_get(&path);
1134         shp->shm_nattch++;
1135         size = i_size_read(path.dentry->d_inode);
1136         ipc_unlock_object(&shp->shm_perm);
1137         rcu_read_unlock();
1138
1139         err = -ENOMEM;
1140         sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
1141         if (!sfd) {
1142                 path_put(&path);
1143                 goto out_nattch;
1144         }
1145
1146         file = alloc_file(&path, f_mode,
1147                           is_file_hugepages(shp->shm_file) ?
1148                                 &shm_file_operations_huge :
1149                                 &shm_file_operations);
1150         err = PTR_ERR(file);
1151         if (IS_ERR(file)) {
1152                 kfree(sfd);
1153                 path_put(&path);
1154                 goto out_nattch;
1155         }
1156
1157         file->private_data = sfd;
1158         file->f_mapping = shp->shm_file->f_mapping;
1159         sfd->id = shp->shm_perm.id;
1160         sfd->ns = get_ipc_ns(ns);
1161         sfd->file = shp->shm_file;
1162         sfd->vm_ops = NULL;
1163
1164         err = security_mmap_file(file, prot, flags);
1165         if (err)
1166                 goto out_fput;
1167
1168         down_write(&current->mm->mmap_sem);
1169         if (addr && !(shmflg & SHM_REMAP)) {
1170                 err = -EINVAL;
1171                 if (addr + size < addr)
1172                         goto invalid;
1173
1174                 if (find_vma_intersection(current->mm, addr, addr + size))
1175                         goto invalid;
1176         }
1177
1178         addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate);
1179         *raddr = addr;
1180         err = 0;
1181         if (IS_ERR_VALUE(addr))
1182                 err = (long)addr;
1183 invalid:
1184         up_write(&current->mm->mmap_sem);
1185         if (populate)
1186                 mm_populate(addr, populate);
1187
1188 out_fput:
1189         fput(file);
1190
1191 out_nattch:
1192         down_write(&shm_ids(ns).rwsem);
1193         shp = shm_lock(ns, shmid);
1194         BUG_ON(IS_ERR(shp));
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         return 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 #endif