linux/ipc/shm.c
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   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
  50struct 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
  59static const struct file_operations shm_file_operations;
  60static 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
  67static int newseg(struct ipc_namespace *, struct ipc_params *);
  68static void shm_open(struct vm_area_struct *vma);
  69static void shm_close(struct vm_area_struct *vma);
  70static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp);
  71#ifdef CONFIG_PROC_FS
  72static int sysvipc_shm_proc_show(struct seq_file *s, void *it);
  73#endif
  74
  75void 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 */
  89static 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
 104void 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
 111static int __init ipc_ns_init(void)
 112{
 113        shm_init_ns(&init_ipc_ns);
 114        return 0;
 115}
 116
 117pure_initcall(ipc_ns_init);
 118
 119void __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
 130static inline struct shmid_kernel *shm_obtain_object(struct ipc_namespace *ns, int id)
 131{
 132        struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&shm_ids(ns), id);
 133
 134        if (IS_ERR(ipcp))
 135                return ERR_CAST(ipcp);
 136
 137        return container_of(ipcp, struct shmid_kernel, shm_perm);
 138}
 139
 140static 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 */
 154static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
 155{
 156        struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
 157
 158        /*
 159         * Callers of shm_lock() must validate the status of the returned ipc
 160         * object pointer (as returned by ipc_lock()), and error out as
 161         * appropriate.
 162         */
 163        if (IS_ERR(ipcp))
 164                return (void *)ipcp;
 165        return container_of(ipcp, struct shmid_kernel, shm_perm);
 166}
 167
 168static inline void shm_lock_by_ptr(struct shmid_kernel *ipcp)
 169{
 170        rcu_read_lock();
 171        ipc_lock_object(&ipcp->shm_perm);
 172}
 173
 174static void shm_rcu_free(struct rcu_head *head)
 175{
 176        struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
 177        struct shmid_kernel *shp = ipc_rcu_to_struct(p);
 178
 179        security_shm_free(shp);
 180        ipc_rcu_free(head);
 181}
 182
 183static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s)
 184{
 185        list_del(&s->shm_clist);
 186        ipc_rmid(&shm_ids(ns), &s->shm_perm);
 187}
 188
 189
 190static int __shm_open(struct vm_area_struct *vma)
 191{
 192        struct file *file = vma->vm_file;
 193        struct shm_file_data *sfd = shm_file_data(file);
 194        struct shmid_kernel *shp;
 195
 196        shp = shm_lock(sfd->ns, sfd->id);
 197
 198        if (IS_ERR(shp))
 199                return PTR_ERR(shp);
 200
 201        shp->shm_atim = get_seconds();
 202        shp->shm_lprid = task_tgid_vnr(current);
 203        shp->shm_nattch++;
 204        shm_unlock(shp);
 205        return 0;
 206}
 207
 208/* This is called by fork, once for every shm attach. */
 209static void shm_open(struct vm_area_struct *vma)
 210{
 211        int err = __shm_open(vma);
 212        /*
 213         * We raced in the idr lookup or with shm_destroy().
 214         * Either way, the ID is busted.
 215         */
 216        WARN_ON_ONCE(err);
 217}
 218
 219/*
 220 * shm_destroy - free the struct shmid_kernel
 221 *
 222 * @ns: namespace
 223 * @shp: struct to free
 224 *
 225 * It has to be called with shp and shm_ids.rwsem (writer) locked,
 226 * but returns with shp unlocked and freed.
 227 */
 228static void shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
 229{
 230        struct file *shm_file;
 231
 232        shm_file = shp->shm_file;
 233        shp->shm_file = NULL;
 234        ns->shm_tot -= (shp->shm_segsz + PAGE_SIZE - 1) >> PAGE_SHIFT;
 235        shm_rmid(ns, shp);
 236        shm_unlock(shp);
 237        if (!is_file_hugepages(shm_file))
 238                shmem_lock(shm_file, 0, shp->mlock_user);
 239        else if (shp->mlock_user)
 240                user_shm_unlock(i_size_read(file_inode(shm_file)),
 241                                shp->mlock_user);
 242        fput(shm_file);
 243        ipc_rcu_putref(shp, shm_rcu_free);
 244}
 245
 246/*
 247 * shm_may_destroy - identifies whether shm segment should be destroyed now
 248 *
 249 * Returns true if and only if there are no active users of the segment and
 250 * one of the following is true:
 251 *
 252 * 1) shmctl(id, IPC_RMID, NULL) was called for this shp
 253 *
 254 * 2) sysctl kernel.shm_rmid_forced is set to 1.
 255 */
 256static bool shm_may_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
 257{
 258        return (shp->shm_nattch == 0) &&
 259               (ns->shm_rmid_forced ||
 260                (shp->shm_perm.mode & SHM_DEST));
 261}
 262
 263/*
 264 * remove the attach descriptor vma.
 265 * free memory for segment if it is marked destroyed.
 266 * The descriptor has already been removed from the current->mm->mmap list
 267 * and will later be kfree()d.
 268 */
 269static void shm_close(struct vm_area_struct *vma)
 270{
 271        struct file *file = vma->vm_file;
 272        struct shm_file_data *sfd = shm_file_data(file);
 273        struct shmid_kernel *shp;
 274        struct ipc_namespace *ns = sfd->ns;
 275
 276        down_write(&shm_ids(ns).rwsem);
 277        /* remove from the list of attaches of the shm segment */
 278        shp = shm_lock(ns, sfd->id);
 279
 280        /*
 281         * We raced in the idr lookup or with shm_destroy().
 282         * Either way, the ID is busted.
 283         */
 284        if (WARN_ON_ONCE(IS_ERR(shp)))
 285                goto done; /* no-op */
 286
 287        shp->shm_lprid = task_tgid_vnr(current);
 288        shp->shm_dtim = get_seconds();
 289        shp->shm_nattch--;
 290        if (shm_may_destroy(ns, shp))
 291                shm_destroy(ns, shp);
 292        else
 293                shm_unlock(shp);
 294done:
 295        up_write(&shm_ids(ns).rwsem);
 296}
 297
 298/* Called with ns->shm_ids(ns).rwsem locked */
 299static int shm_try_destroy_orphaned(int id, void *p, void *data)
 300{
 301        struct ipc_namespace *ns = data;
 302        struct kern_ipc_perm *ipcp = p;
 303        struct shmid_kernel *shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 304
 305        /*
 306         * We want to destroy segments without users and with already
 307         * exit'ed originating process.
 308         *
 309         * As shp->* are changed under rwsem, it's safe to skip shp locking.
 310         */
 311        if (shp->shm_creator != NULL)
 312                return 0;
 313
 314        if (shm_may_destroy(ns, shp)) {
 315                shm_lock_by_ptr(shp);
 316                shm_destroy(ns, shp);
 317        }
 318        return 0;
 319}
 320
 321void shm_destroy_orphaned(struct ipc_namespace *ns)
 322{
 323        down_write(&shm_ids(ns).rwsem);
 324        if (shm_ids(ns).in_use)
 325                idr_for_each(&shm_ids(ns).ipcs_idr, &shm_try_destroy_orphaned, ns);
 326        up_write(&shm_ids(ns).rwsem);
 327}
 328
 329/* Locking assumes this will only be called with task == current */
 330void exit_shm(struct task_struct *task)
 331{
 332        struct ipc_namespace *ns = task->nsproxy->ipc_ns;
 333        struct shmid_kernel *shp, *n;
 334
 335        if (list_empty(&task->sysvshm.shm_clist))
 336                return;
 337
 338        /*
 339         * If kernel.shm_rmid_forced is not set then only keep track of
 340         * which shmids are orphaned, so that a later set of the sysctl
 341         * can clean them up.
 342         */
 343        if (!ns->shm_rmid_forced) {
 344                down_read(&shm_ids(ns).rwsem);
 345                list_for_each_entry(shp, &task->sysvshm.shm_clist, shm_clist)
 346                        shp->shm_creator = NULL;
 347                /*
 348                 * Only under read lock but we are only called on current
 349                 * so no entry on the list will be shared.
 350                 */
 351                list_del(&task->sysvshm.shm_clist);
 352                up_read(&shm_ids(ns).rwsem);
 353                return;
 354        }
 355
 356        /*
 357         * Destroy all already created segments, that were not yet mapped,
 358         * and mark any mapped as orphan to cover the sysctl toggling.
 359         * Destroy is skipped if shm_may_destroy() returns false.
 360         */
 361        down_write(&shm_ids(ns).rwsem);
 362        list_for_each_entry_safe(shp, n, &task->sysvshm.shm_clist, shm_clist) {
 363                shp->shm_creator = NULL;
 364
 365                if (shm_may_destroy(ns, shp)) {
 366                        shm_lock_by_ptr(shp);
 367                        shm_destroy(ns, shp);
 368                }
 369        }
 370
 371        /* Remove the list head from any segments still attached. */
 372        list_del(&task->sysvshm.shm_clist);
 373        up_write(&shm_ids(ns).rwsem);
 374}
 375
 376static int shm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 377{
 378        struct file *file = vma->vm_file;
 379        struct shm_file_data *sfd = shm_file_data(file);
 380
 381        return sfd->vm_ops->fault(vma, vmf);
 382}
 383
 384#ifdef CONFIG_NUMA
 385static int shm_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
 386{
 387        struct file *file = vma->vm_file;
 388        struct shm_file_data *sfd = shm_file_data(file);
 389        int err = 0;
 390        if (sfd->vm_ops->set_policy)
 391                err = sfd->vm_ops->set_policy(vma, new);
 392        return err;
 393}
 394
 395static struct mempolicy *shm_get_policy(struct vm_area_struct *vma,
 396                                        unsigned long addr)
 397{
 398        struct file *file = vma->vm_file;
 399        struct shm_file_data *sfd = shm_file_data(file);
 400        struct mempolicy *pol = NULL;
 401
 402        if (sfd->vm_ops->get_policy)
 403                pol = sfd->vm_ops->get_policy(vma, addr);
 404        else if (vma->vm_policy)
 405                pol = vma->vm_policy;
 406
 407        return pol;
 408}
 409#endif
 410
 411static int shm_mmap(struct file *file, struct vm_area_struct *vma)
 412{
 413        struct shm_file_data *sfd = shm_file_data(file);
 414        int ret;
 415
 416        /*
 417         * In case of remap_file_pages() emulation, the file can represent
 418         * removed IPC ID: propogate shm_lock() error to caller.
 419         */
 420        ret =__shm_open(vma);
 421        if (ret)
 422                return ret;
 423
 424        ret = sfd->file->f_op->mmap(sfd->file, vma);
 425        if (ret) {
 426                shm_close(vma);
 427                return ret;
 428        }
 429        sfd->vm_ops = vma->vm_ops;
 430#ifdef CONFIG_MMU
 431        WARN_ON(!sfd->vm_ops->fault);
 432#endif
 433        vma->vm_ops = &shm_vm_ops;
 434        return 0;
 435}
 436
 437static int shm_release(struct inode *ino, struct file *file)
 438{
 439        struct shm_file_data *sfd = shm_file_data(file);
 440
 441        put_ipc_ns(sfd->ns);
 442        shm_file_data(file) = NULL;
 443        kfree(sfd);
 444        return 0;
 445}
 446
 447static int shm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 448{
 449        struct shm_file_data *sfd = shm_file_data(file);
 450
 451        if (!sfd->file->f_op->fsync)
 452                return -EINVAL;
 453        return sfd->file->f_op->fsync(sfd->file, start, end, datasync);
 454}
 455
 456static long shm_fallocate(struct file *file, int mode, loff_t offset,
 457                          loff_t len)
 458{
 459        struct shm_file_data *sfd = shm_file_data(file);
 460
 461        if (!sfd->file->f_op->fallocate)
 462                return -EOPNOTSUPP;
 463        return sfd->file->f_op->fallocate(file, mode, offset, len);
 464}
 465
 466static unsigned long shm_get_unmapped_area(struct file *file,
 467        unsigned long addr, unsigned long len, unsigned long pgoff,
 468        unsigned long flags)
 469{
 470        struct shm_file_data *sfd = shm_file_data(file);
 471        return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len,
 472                                                pgoff, flags);
 473}
 474
 475static const struct file_operations shm_file_operations = {
 476        .mmap           = shm_mmap,
 477        .fsync          = shm_fsync,
 478        .release        = shm_release,
 479#ifndef CONFIG_MMU
 480        .get_unmapped_area      = shm_get_unmapped_area,
 481#endif
 482        .llseek         = noop_llseek,
 483        .fallocate      = shm_fallocate,
 484};
 485
 486static const struct file_operations shm_file_operations_huge = {
 487        .mmap           = shm_mmap,
 488        .fsync          = shm_fsync,
 489        .release        = shm_release,
 490        .get_unmapped_area      = shm_get_unmapped_area,
 491        .llseek         = noop_llseek,
 492        .fallocate      = shm_fallocate,
 493};
 494
 495bool is_file_shm_hugepages(struct file *file)
 496{
 497        return file->f_op == &shm_file_operations_huge;
 498}
 499
 500static const struct vm_operations_struct shm_vm_ops = {
 501        .open   = shm_open,     /* callback for a new vm-area open */
 502        .close  = shm_close,    /* callback for when the vm-area is released */
 503        .fault  = shm_fault,
 504#if defined(CONFIG_NUMA)
 505        .set_policy = shm_set_policy,
 506        .get_policy = shm_get_policy,
 507#endif
 508};
 509
 510/**
 511 * newseg - Create a new shared memory segment
 512 * @ns: namespace
 513 * @params: ptr to the structure that contains key, size and shmflg
 514 *
 515 * Called with shm_ids.rwsem held as a writer.
 516 */
 517static int newseg(struct ipc_namespace *ns, struct ipc_params *params)
 518{
 519        key_t key = params->key;
 520        int shmflg = params->flg;
 521        size_t size = params->u.size;
 522        int error;
 523        struct shmid_kernel *shp;
 524        size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 525        struct file *file;
 526        char name[13];
 527        int id;
 528        vm_flags_t acctflag = 0;
 529
 530        if (size < SHMMIN || size > ns->shm_ctlmax)
 531                return -EINVAL;
 532
 533        if (numpages << PAGE_SHIFT < size)
 534                return -ENOSPC;
 535
 536        if (ns->shm_tot + numpages < ns->shm_tot ||
 537                        ns->shm_tot + numpages > ns->shm_ctlall)
 538                return -ENOSPC;
 539
 540        shp = ipc_rcu_alloc(sizeof(*shp));
 541        if (!shp)
 542                return -ENOMEM;
 543
 544        shp->shm_perm.key = key;
 545        shp->shm_perm.mode = (shmflg & S_IRWXUGO);
 546        shp->mlock_user = NULL;
 547
 548        shp->shm_perm.security = NULL;
 549        error = security_shm_alloc(shp);
 550        if (error) {
 551                ipc_rcu_putref(shp, ipc_rcu_free);
 552                return error;
 553        }
 554
 555        sprintf(name, "SYSV%08x", key);
 556        if (shmflg & SHM_HUGETLB) {
 557                struct hstate *hs;
 558                size_t hugesize;
 559
 560                hs = hstate_sizelog((shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
 561                if (!hs) {
 562                        error = -EINVAL;
 563                        goto no_file;
 564                }
 565                hugesize = ALIGN(size, huge_page_size(hs));
 566
 567                /* hugetlb_file_setup applies strict accounting */
 568                if (shmflg & SHM_NORESERVE)
 569                        acctflag = VM_NORESERVE;
 570                file = hugetlb_file_setup(name, hugesize, acctflag,
 571                                  &shp->mlock_user, HUGETLB_SHMFS_INODE,
 572                                (shmflg >> SHM_HUGE_SHIFT) & SHM_HUGE_MASK);
 573        } else {
 574                /*
 575                 * Do not allow no accounting for OVERCOMMIT_NEVER, even
 576                 * if it's asked for.
 577                 */
 578                if  ((shmflg & SHM_NORESERVE) &&
 579                                sysctl_overcommit_memory != OVERCOMMIT_NEVER)
 580                        acctflag = VM_NORESERVE;
 581                file = shmem_kernel_file_setup(name, size, acctflag);
 582        }
 583        error = PTR_ERR(file);
 584        if (IS_ERR(file))
 585                goto no_file;
 586
 587        shp->shm_cprid = task_tgid_vnr(current);
 588        shp->shm_lprid = 0;
 589        shp->shm_atim = shp->shm_dtim = 0;
 590        shp->shm_ctim = get_seconds();
 591        shp->shm_segsz = size;
 592        shp->shm_nattch = 0;
 593        shp->shm_file = file;
 594        shp->shm_creator = current;
 595
 596        id = ipc_addid(&shm_ids(ns), &shp->shm_perm, ns->shm_ctlmni);
 597        if (id < 0) {
 598                error = id;
 599                goto no_id;
 600        }
 601
 602        list_add(&shp->shm_clist, &current->sysvshm.shm_clist);
 603
 604        /*
 605         * shmid gets reported as "inode#" in /proc/pid/maps.
 606         * proc-ps tools use this. Changing this will break them.
 607         */
 608        file_inode(file)->i_ino = shp->shm_perm.id;
 609
 610        ns->shm_tot += numpages;
 611        error = shp->shm_perm.id;
 612
 613        ipc_unlock_object(&shp->shm_perm);
 614        rcu_read_unlock();
 615        return error;
 616
 617no_id:
 618        if (is_file_hugepages(file) && shp->mlock_user)
 619                user_shm_unlock(size, shp->mlock_user);
 620        fput(file);
 621no_file:
 622        ipc_rcu_putref(shp, shm_rcu_free);
 623        return error;
 624}
 625
 626/*
 627 * Called with shm_ids.rwsem and ipcp locked.
 628 */
 629static inline int shm_security(struct kern_ipc_perm *ipcp, int shmflg)
 630{
 631        struct shmid_kernel *shp;
 632
 633        shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 634        return security_shm_associate(shp, shmflg);
 635}
 636
 637/*
 638 * Called with shm_ids.rwsem and ipcp locked.
 639 */
 640static inline int shm_more_checks(struct kern_ipc_perm *ipcp,
 641                                struct ipc_params *params)
 642{
 643        struct shmid_kernel *shp;
 644
 645        shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 646        if (shp->shm_segsz < params->u.size)
 647                return -EINVAL;
 648
 649        return 0;
 650}
 651
 652SYSCALL_DEFINE3(shmget, key_t, key, size_t, size, int, shmflg)
 653{
 654        struct ipc_namespace *ns;
 655        static const struct ipc_ops shm_ops = {
 656                .getnew = newseg,
 657                .associate = shm_security,
 658                .more_checks = shm_more_checks,
 659        };
 660        struct ipc_params shm_params;
 661
 662        ns = current->nsproxy->ipc_ns;
 663
 664        shm_params.key = key;
 665        shm_params.flg = shmflg;
 666        shm_params.u.size = size;
 667
 668        return ipcget(ns, &shm_ids(ns), &shm_ops, &shm_params);
 669}
 670
 671static inline unsigned long copy_shmid_to_user(void __user *buf, struct shmid64_ds *in, int version)
 672{
 673        switch (version) {
 674        case IPC_64:
 675                return copy_to_user(buf, in, sizeof(*in));
 676        case IPC_OLD:
 677            {
 678                struct shmid_ds out;
 679
 680                memset(&out, 0, sizeof(out));
 681                ipc64_perm_to_ipc_perm(&in->shm_perm, &out.shm_perm);
 682                out.shm_segsz   = in->shm_segsz;
 683                out.shm_atime   = in->shm_atime;
 684                out.shm_dtime   = in->shm_dtime;
 685                out.shm_ctime   = in->shm_ctime;
 686                out.shm_cpid    = in->shm_cpid;
 687                out.shm_lpid    = in->shm_lpid;
 688                out.shm_nattch  = in->shm_nattch;
 689
 690                return copy_to_user(buf, &out, sizeof(out));
 691            }
 692        default:
 693                return -EINVAL;
 694        }
 695}
 696
 697static inline unsigned long
 698copy_shmid_from_user(struct shmid64_ds *out, void __user *buf, int version)
 699{
 700        switch (version) {
 701        case IPC_64:
 702                if (copy_from_user(out, buf, sizeof(*out)))
 703                        return -EFAULT;
 704                return 0;
 705        case IPC_OLD:
 706            {
 707                struct shmid_ds tbuf_old;
 708
 709                if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
 710                        return -EFAULT;
 711
 712                out->shm_perm.uid       = tbuf_old.shm_perm.uid;
 713                out->shm_perm.gid       = tbuf_old.shm_perm.gid;
 714                out->shm_perm.mode      = tbuf_old.shm_perm.mode;
 715
 716                return 0;
 717            }
 718        default:
 719                return -EINVAL;
 720        }
 721}
 722
 723static inline unsigned long copy_shminfo_to_user(void __user *buf, struct shminfo64 *in, int version)
 724{
 725        switch (version) {
 726        case IPC_64:
 727                return copy_to_user(buf, in, sizeof(*in));
 728        case IPC_OLD:
 729            {
 730                struct shminfo out;
 731
 732                if (in->shmmax > INT_MAX)
 733                        out.shmmax = INT_MAX;
 734                else
 735                        out.shmmax = (int)in->shmmax;
 736
 737                out.shmmin      = in->shmmin;
 738                out.shmmni      = in->shmmni;
 739                out.shmseg      = in->shmseg;
 740                out.shmall      = in->shmall;
 741
 742                return copy_to_user(buf, &out, sizeof(out));
 743            }
 744        default:
 745                return -EINVAL;
 746        }
 747}
 748
 749/*
 750 * Calculate and add used RSS and swap pages of a shm.
 751 * Called with shm_ids.rwsem held as a reader
 752 */
 753static void shm_add_rss_swap(struct shmid_kernel *shp,
 754        unsigned long *rss_add, unsigned long *swp_add)
 755{
 756        struct inode *inode;
 757
 758        inode = file_inode(shp->shm_file);
 759
 760        if (is_file_hugepages(shp->shm_file)) {
 761                struct address_space *mapping = inode->i_mapping;
 762                struct hstate *h = hstate_file(shp->shm_file);
 763                *rss_add += pages_per_huge_page(h) * mapping->nrpages;
 764        } else {
 765#ifdef CONFIG_SHMEM
 766                struct shmem_inode_info *info = SHMEM_I(inode);
 767                spin_lock(&info->lock);
 768                *rss_add += inode->i_mapping->nrpages;
 769                *swp_add += info->swapped;
 770                spin_unlock(&info->lock);
 771#else
 772                *rss_add += inode->i_mapping->nrpages;
 773#endif
 774        }
 775}
 776
 777/*
 778 * Called with shm_ids.rwsem held as a reader
 779 */
 780static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
 781                unsigned long *swp)
 782{
 783        int next_id;
 784        int total, in_use;
 785
 786        *rss = 0;
 787        *swp = 0;
 788
 789        in_use = shm_ids(ns).in_use;
 790
 791        for (total = 0, next_id = 0; total < in_use; next_id++) {
 792                struct kern_ipc_perm *ipc;
 793                struct shmid_kernel *shp;
 794
 795                ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
 796                if (ipc == NULL)
 797                        continue;
 798                shp = container_of(ipc, struct shmid_kernel, shm_perm);
 799
 800                shm_add_rss_swap(shp, rss, swp);
 801
 802                total++;
 803        }
 804}
 805
 806/*
 807 * This function handles some shmctl commands which require the rwsem
 808 * to be held in write mode.
 809 * NOTE: no locks must be held, the rwsem is taken inside this function.
 810 */
 811static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
 812                       struct shmid_ds __user *buf, int version)
 813{
 814        struct kern_ipc_perm *ipcp;
 815        struct shmid64_ds shmid64;
 816        struct shmid_kernel *shp;
 817        int err;
 818
 819        if (cmd == IPC_SET) {
 820                if (copy_shmid_from_user(&shmid64, buf, version))
 821                        return -EFAULT;
 822        }
 823
 824        down_write(&shm_ids(ns).rwsem);
 825        rcu_read_lock();
 826
 827        ipcp = ipcctl_pre_down_nolock(ns, &shm_ids(ns), shmid, cmd,
 828                                      &shmid64.shm_perm, 0);
 829        if (IS_ERR(ipcp)) {
 830                err = PTR_ERR(ipcp);
 831                goto out_unlock1;
 832        }
 833
 834        shp = container_of(ipcp, struct shmid_kernel, shm_perm);
 835
 836        err = security_shm_shmctl(shp, cmd);
 837        if (err)
 838                goto out_unlock1;
 839
 840        switch (cmd) {
 841        case IPC_RMID:
 842                ipc_lock_object(&shp->shm_perm);
 843                /* do_shm_rmid unlocks the ipc object and rcu */
 844                do_shm_rmid(ns, ipcp);
 845                goto out_up;
 846        case IPC_SET:
 847                ipc_lock_object(&shp->shm_perm);
 848                err = ipc_update_perm(&shmid64.shm_perm, ipcp);
 849                if (err)
 850                        goto out_unlock0;
 851                shp->shm_ctim = get_seconds();
 852                break;
 853        default:
 854                err = -EINVAL;
 855                goto out_unlock1;
 856        }
 857
 858out_unlock0:
 859        ipc_unlock_object(&shp->shm_perm);
 860out_unlock1:
 861        rcu_read_unlock();
 862out_up:
 863        up_write(&shm_ids(ns).rwsem);
 864        return err;
 865}
 866
 867static int shmctl_nolock(struct ipc_namespace *ns, int shmid,
 868                         int cmd, int version, void __user *buf)
 869{
 870        int err;
 871        struct shmid_kernel *shp;
 872
 873        /* preliminary security checks for *_INFO */
 874        if (cmd == IPC_INFO || cmd == SHM_INFO) {
 875                err = security_shm_shmctl(NULL, cmd);
 876                if (err)
 877                        return err;
 878        }
 879
 880        switch (cmd) {
 881        case IPC_INFO:
 882        {
 883                struct shminfo64 shminfo;
 884
 885                memset(&shminfo, 0, sizeof(shminfo));
 886                shminfo.shmmni = shminfo.shmseg = ns->shm_ctlmni;
 887                shminfo.shmmax = ns->shm_ctlmax;
 888                shminfo.shmall = ns->shm_ctlall;
 889
 890                shminfo.shmmin = SHMMIN;
 891                if (copy_shminfo_to_user(buf, &shminfo, version))
 892                        return -EFAULT;
 893
 894                down_read(&shm_ids(ns).rwsem);
 895                err = ipc_get_maxid(&shm_ids(ns));
 896                up_read(&shm_ids(ns).rwsem);
 897
 898                if (err < 0)
 899                        err = 0;
 900                goto out;
 901        }
 902        case SHM_INFO:
 903        {
 904                struct shm_info shm_info;
 905
 906                memset(&shm_info, 0, sizeof(shm_info));
 907                down_read(&shm_ids(ns).rwsem);
 908                shm_info.used_ids = shm_ids(ns).in_use;
 909                shm_get_stat(ns, &shm_info.shm_rss, &shm_info.shm_swp);
 910                shm_info.shm_tot = ns->shm_tot;
 911                shm_info.swap_attempts = 0;
 912                shm_info.swap_successes = 0;
 913                err = ipc_get_maxid(&shm_ids(ns));
 914                up_read(&shm_ids(ns).rwsem);
 915                if (copy_to_user(buf, &shm_info, sizeof(shm_info))) {
 916                        err = -EFAULT;
 917                        goto out;
 918                }
 919
 920                err = err < 0 ? 0 : err;
 921                goto out;
 922        }
 923        case SHM_STAT:
 924        case IPC_STAT:
 925        {
 926                struct shmid64_ds tbuf;
 927                int result;
 928
 929                rcu_read_lock();
 930                if (cmd == SHM_STAT) {
 931                        shp = shm_obtain_object(ns, shmid);
 932                        if (IS_ERR(shp)) {
 933                                err = PTR_ERR(shp);
 934                                goto out_unlock;
 935                        }
 936                        result = shp->shm_perm.id;
 937                } else {
 938                        shp = shm_obtain_object_check(ns, shmid);
 939                        if (IS_ERR(shp)) {
 940                                err = PTR_ERR(shp);
 941                                goto out_unlock;
 942                        }
 943                        result = 0;
 944                }
 945
 946                err = -EACCES;
 947                if (ipcperms(ns, &shp->shm_perm, S_IRUGO))
 948                        goto out_unlock;
 949
 950                err = security_shm_shmctl(shp, cmd);
 951                if (err)
 952                        goto out_unlock;
 953
 954                memset(&tbuf, 0, sizeof(tbuf));
 955                kernel_to_ipc64_perm(&shp->shm_perm, &tbuf.shm_perm);
 956                tbuf.shm_segsz  = shp->shm_segsz;
 957                tbuf.shm_atime  = shp->shm_atim;
 958                tbuf.shm_dtime  = shp->shm_dtim;
 959                tbuf.shm_ctime  = shp->shm_ctim;
 960                tbuf.shm_cpid   = shp->shm_cprid;
 961                tbuf.shm_lpid   = shp->shm_lprid;
 962                tbuf.shm_nattch = shp->shm_nattch;
 963                rcu_read_unlock();
 964
 965                if (copy_shmid_to_user(buf, &tbuf, version))
 966                        err = -EFAULT;
 967                else
 968                        err = result;
 969                goto out;
 970        }
 971        default:
 972                return -EINVAL;
 973        }
 974
 975out_unlock:
 976        rcu_read_unlock();
 977out:
 978        return err;
 979}
 980
 981SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
 982{
 983        struct shmid_kernel *shp;
 984        int err, version;
 985        struct ipc_namespace *ns;
 986
 987        if (cmd < 0 || shmid < 0)
 988                return -EINVAL;
 989
 990        version = ipc_parse_version(&cmd);
 991        ns = current->nsproxy->ipc_ns;
 992
 993        switch (cmd) {
 994        case IPC_INFO:
 995        case SHM_INFO:
 996        case SHM_STAT:
 997        case IPC_STAT:
 998                return shmctl_nolock(ns, shmid, cmd, version, buf);
 999        case IPC_RMID:
1000        case IPC_SET:
1001                return shmctl_down(ns, shmid, cmd, buf, version);
1002        case SHM_LOCK:
1003        case SHM_UNLOCK:
1004        {
1005                struct file *shm_file;
1006
1007                rcu_read_lock();
1008                shp = shm_obtain_object_check(ns, shmid);
1009                if (IS_ERR(shp)) {
1010                        err = PTR_ERR(shp);
1011                        goto out_unlock1;
1012                }
1013
1014                audit_ipc_obj(&(shp->shm_perm));
1015                err = security_shm_shmctl(shp, cmd);
1016                if (err)
1017                        goto out_unlock1;
1018
1019                ipc_lock_object(&shp->shm_perm);
1020
1021                /* check if shm_destroy() is tearing down shp */
1022                if (!ipc_valid_object(&shp->shm_perm)) {
1023                        err = -EIDRM;
1024                        goto out_unlock0;
1025                }
1026
1027                if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
1028                        kuid_t euid = current_euid();
1029                        if (!uid_eq(euid, shp->shm_perm.uid) &&
1030                            !uid_eq(euid, shp->shm_perm.cuid)) {
1031                                err = -EPERM;
1032                                goto out_unlock0;
1033                        }
1034                        if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK)) {
1035                                err = -EPERM;
1036                                goto out_unlock0;
1037                        }
1038                }
1039
1040                shm_file = shp->shm_file;
1041                if (is_file_hugepages(shm_file))
1042                        goto out_unlock0;
1043
1044                if (cmd == SHM_LOCK) {
1045                        struct user_struct *user = current_user();
1046                        err = shmem_lock(shm_file, 1, user);
1047                        if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
1048                                shp->shm_perm.mode |= SHM_LOCKED;
1049                                shp->mlock_user = user;
1050                        }
1051                        goto out_unlock0;
1052                }
1053
1054                /* SHM_UNLOCK */
1055                if (!(shp->shm_perm.mode & SHM_LOCKED))
1056                        goto out_unlock0;
1057                shmem_lock(shm_file, 0, shp->mlock_user);
1058                shp->shm_perm.mode &= ~SHM_LOCKED;
1059                shp->mlock_user = NULL;
1060                get_file(shm_file);
1061                ipc_unlock_object(&shp->shm_perm);
1062                rcu_read_unlock();
1063                shmem_unlock_mapping(shm_file->f_mapping);
1064
1065                fput(shm_file);
1066                return err;
1067        }
1068        default:
1069                return -EINVAL;
1070        }
1071
1072out_unlock0:
1073        ipc_unlock_object(&shp->shm_perm);
1074out_unlock1:
1075        rcu_read_unlock();
1076        return err;
1077}
1078
1079/*
1080 * Fix shmaddr, allocate descriptor, map shm, add attach descriptor to lists.
1081 *
1082 * NOTE! Despite the name, this is NOT a direct system call entrypoint. The
1083 * "raddr" thing points to kernel space, and there has to be a wrapper around
1084 * this.
1085 */
1086long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
1087              unsigned long shmlba)
1088{
1089        struct shmid_kernel *shp;
1090        unsigned long addr;
1091        unsigned long size;
1092        struct file *file;
1093        int    err;
1094        unsigned long flags;
1095        unsigned long prot;
1096        int acc_mode;
1097        struct ipc_namespace *ns;
1098        struct shm_file_data *sfd;
1099        struct path path;
1100        fmode_t f_mode;
1101        unsigned long populate = 0;
1102
1103        err = -EINVAL;
1104        if (shmid < 0)
1105                goto out;
1106        else if ((addr = (ulong)shmaddr)) {
1107                if (addr & (shmlba - 1)) {
1108                        if (shmflg & SHM_RND)
1109                                addr &= ~(shmlba - 1);     /* round down */
1110                        else
1111#ifndef __ARCH_FORCE_SHMLBA
1112                                if (addr & ~PAGE_MASK)
1113#endif
1114                                        goto out;
1115                }
1116                flags = MAP_SHARED | MAP_FIXED;
1117        } else {
1118                if ((shmflg & SHM_REMAP))
1119                        goto out;
1120
1121                flags = MAP_SHARED;
1122        }
1123
1124        if (shmflg & SHM_RDONLY) {
1125                prot = PROT_READ;
1126                acc_mode = S_IRUGO;
1127                f_mode = FMODE_READ;
1128        } else {
1129                prot = PROT_READ | PROT_WRITE;
1130                acc_mode = S_IRUGO | S_IWUGO;
1131                f_mode = FMODE_READ | FMODE_WRITE;
1132        }
1133        if (shmflg & SHM_EXEC) {
1134                prot |= PROT_EXEC;
1135                acc_mode |= S_IXUGO;
1136        }
1137
1138        /*
1139         * We cannot rely on the fs check since SYSV IPC does have an
1140         * additional creator id...
1141         */
1142        ns = current->nsproxy->ipc_ns;
1143        rcu_read_lock();
1144        shp = shm_obtain_object_check(ns, shmid);
1145        if (IS_ERR(shp)) {
1146                err = PTR_ERR(shp);
1147                goto out_unlock;
1148        }
1149
1150        err = -EACCES;
1151        if (ipcperms(ns, &shp->shm_perm, acc_mode))
1152                goto out_unlock;
1153
1154        err = security_shm_shmat(shp, shmaddr, shmflg);
1155        if (err)
1156                goto out_unlock;
1157
1158        ipc_lock_object(&shp->shm_perm);
1159
1160        /* check if shm_destroy() is tearing down shp */
1161        if (!ipc_valid_object(&shp->shm_perm)) {
1162                ipc_unlock_object(&shp->shm_perm);
1163                err = -EIDRM;
1164                goto out_unlock;
1165        }
1166
1167        path = shp->shm_file->f_path;
1168        path_get(&path);
1169        shp->shm_nattch++;
1170        size = i_size_read(d_inode(path.dentry));
1171        ipc_unlock_object(&shp->shm_perm);
1172        rcu_read_unlock();
1173
1174        err = -ENOMEM;
1175        sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
1176        if (!sfd) {
1177                path_put(&path);
1178                goto out_nattch;
1179        }
1180
1181        file = alloc_file(&path, f_mode,
1182                          is_file_hugepages(shp->shm_file) ?
1183                                &shm_file_operations_huge :
1184                                &shm_file_operations);
1185        err = PTR_ERR(file);
1186        if (IS_ERR(file)) {
1187                kfree(sfd);
1188                path_put(&path);
1189                goto out_nattch;
1190        }
1191
1192        file->private_data = sfd;
1193        file->f_mapping = shp->shm_file->f_mapping;
1194        sfd->id = shp->shm_perm.id;
1195        sfd->ns = get_ipc_ns(ns);
1196        sfd->file = shp->shm_file;
1197        sfd->vm_ops = NULL;
1198
1199        err = security_mmap_file(file, prot, flags);
1200        if (err)
1201                goto out_fput;
1202
1203        down_write(&current->mm->mmap_sem);
1204        if (addr && !(shmflg & SHM_REMAP)) {
1205                err = -EINVAL;
1206                if (addr + size < addr)
1207                        goto invalid;
1208
1209                if (find_vma_intersection(current->mm, addr, addr + size))
1210                        goto invalid;
1211        }
1212
1213        addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate);
1214        *raddr = addr;
1215        err = 0;
1216        if (IS_ERR_VALUE(addr))
1217                err = (long)addr;
1218invalid:
1219        up_write(&current->mm->mmap_sem);
1220        if (populate)
1221                mm_populate(addr, populate);
1222
1223out_fput:
1224        fput(file);
1225
1226out_nattch:
1227        down_write(&shm_ids(ns).rwsem);
1228        shp = shm_lock(ns, shmid);
1229        shp->shm_nattch--;
1230        if (shm_may_destroy(ns, shp))
1231                shm_destroy(ns, shp);
1232        else
1233                shm_unlock(shp);
1234        up_write(&shm_ids(ns).rwsem);
1235        return err;
1236
1237out_unlock:
1238        rcu_read_unlock();
1239out:
1240        return err;
1241}
1242
1243SYSCALL_DEFINE3(shmat, int, shmid, char __user *, shmaddr, int, shmflg)
1244{
1245        unsigned long ret;
1246        long err;
1247
1248        err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
1249        if (err)
1250                return err;
1251        force_successful_syscall_return();
1252        return (long)ret;
1253}
1254
1255/*
1256 * detach and kill segment if marked destroyed.
1257 * The work is done in shm_close.
1258 */
1259SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
1260{
1261        struct mm_struct *mm = current->mm;
1262        struct vm_area_struct *vma;
1263        unsigned long addr = (unsigned long)shmaddr;
1264        int retval = -EINVAL;
1265#ifdef CONFIG_MMU
1266        loff_t size = 0;
1267        struct file *file;
1268        struct vm_area_struct *next;
1269#endif
1270
1271        if (addr & ~PAGE_MASK)
1272                return retval;
1273
1274        down_write(&mm->mmap_sem);
1275
1276        /*
1277         * This function tries to be smart and unmap shm segments that
1278         * were modified by partial mlock or munmap calls:
1279         * - It first determines the size of the shm segment that should be
1280         *   unmapped: It searches for a vma that is backed by shm and that
1281         *   started at address shmaddr. It records it's size and then unmaps
1282         *   it.
1283         * - Then it unmaps all shm vmas that started at shmaddr and that
1284         *   are within the initially determined size and that are from the
1285         *   same shm segment from which we determined the size.
1286         * Errors from do_munmap are ignored: the function only fails if
1287         * it's called with invalid parameters or if it's called to unmap
1288         * a part of a vma. Both calls in this function are for full vmas,
1289         * the parameters are directly copied from the vma itself and always
1290         * valid - therefore do_munmap cannot fail. (famous last words?)
1291         */
1292        /*
1293         * If it had been mremap()'d, the starting address would not
1294         * match the usual checks anyway. So assume all vma's are
1295         * above the starting address given.
1296         */
1297        vma = find_vma(mm, addr);
1298
1299#ifdef CONFIG_MMU
1300        while (vma) {
1301                next = vma->vm_next;
1302
1303                /*
1304                 * Check if the starting address would match, i.e. it's
1305                 * a fragment created by mprotect() and/or munmap(), or it
1306                 * otherwise it starts at this address with no hassles.
1307                 */
1308                if ((vma->vm_ops == &shm_vm_ops) &&
1309                        (vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) {
1310
1311                        /*
1312                         * Record the file of the shm segment being
1313                         * unmapped.  With mremap(), someone could place
1314                         * page from another segment but with equal offsets
1315                         * in the range we are unmapping.
1316                         */
1317                        file = vma->vm_file;
1318                        size = i_size_read(file_inode(vma->vm_file));
1319                        do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1320                        /*
1321                         * We discovered the size of the shm segment, so
1322                         * break out of here and fall through to the next
1323                         * loop that uses the size information to stop
1324                         * searching for matching vma's.
1325                         */
1326                        retval = 0;
1327                        vma = next;
1328                        break;
1329                }
1330                vma = next;
1331        }
1332
1333        /*
1334         * We need look no further than the maximum address a fragment
1335         * could possibly have landed at. Also cast things to loff_t to
1336         * prevent overflows and make comparisons vs. equal-width types.
1337         */
1338        size = PAGE_ALIGN(size);
1339        while (vma && (loff_t)(vma->vm_end - addr) <= size) {
1340                next = vma->vm_next;
1341
1342                /* finding a matching vma now does not alter retval */
1343                if ((vma->vm_ops == &shm_vm_ops) &&
1344                    ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) &&
1345                    (vma->vm_file == file))
1346                        do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1347                vma = next;
1348        }
1349
1350#else /* CONFIG_MMU */
1351        /* under NOMMU conditions, the exact address to be destroyed must be
1352         * given */
1353        if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
1354                do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
1355                retval = 0;
1356        }
1357
1358#endif
1359
1360        up_write(&mm->mmap_sem);
1361        return retval;
1362}
1363
1364#ifdef CONFIG_PROC_FS
1365static int sysvipc_shm_proc_show(struct seq_file *s, void *it)
1366{
1367        struct user_namespace *user_ns = seq_user_ns(s);
1368        struct shmid_kernel *shp = it;
1369        unsigned long rss = 0, swp = 0;
1370
1371        shm_add_rss_swap(shp, &rss, &swp);
1372
1373#if BITS_PER_LONG <= 32
1374#define SIZE_SPEC "%10lu"
1375#else
1376#define SIZE_SPEC "%21lu"
1377#endif
1378
1379        seq_printf(s,
1380                   "%10d %10d  %4o " SIZE_SPEC " %5u %5u  "
1381                   "%5lu %5u %5u %5u %5u %10lu %10lu %10lu "
1382                   SIZE_SPEC " " SIZE_SPEC "\n",
1383                   shp->shm_perm.key,
1384                   shp->shm_perm.id,
1385                   shp->shm_perm.mode,
1386                   shp->shm_segsz,
1387                   shp->shm_cprid,
1388                   shp->shm_lprid,
1389                   shp->shm_nattch,
1390                   from_kuid_munged(user_ns, shp->shm_perm.uid),
1391                   from_kgid_munged(user_ns, shp->shm_perm.gid),
1392                   from_kuid_munged(user_ns, shp->shm_perm.cuid),
1393                   from_kgid_munged(user_ns, shp->shm_perm.cgid),
1394                   shp->shm_atim,
1395                   shp->shm_dtim,
1396                   shp->shm_ctim,
1397                   rss * PAGE_SIZE,
1398                   swp * PAGE_SIZE);
1399
1400        return 0;
1401}
1402#endif
1403