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