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