kernel/fork.c

   1 /*
   2  *  linux/kernel/fork.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 /*
   8  *  'fork.c' contains the help-routines for the 'fork' system call
   9  * (see also entry.S and others).
  10  * Fork is rather simple, once you get the hang of it, but the memory
  11  * management can be a bitch. See 'mm/memory.c': 'copy_page_range()'
  12  */
  13
  14 #include <linux/config.h>
  15 #include <linux/slab.h>
  16 #include <linux/init.h>
  17 #include <linux/unistd.h>
  18 #include <linux/smp_lock.h>
  19 #include <linux/module.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/completion.h>
  22 #include <linux/namespace.h>
  23 #include <linux/personality.h>
  24 #include <linux/mempolicy.h>
  25 #include <linux/sem.h>
  26 #include <linux/file.h>
  27 #include <linux/binfmts.h>
  28 #include <linux/mman.h>
  29 #include <linux/fs.h>
  30 #include <linux/cpu.h>
  31 #include <linux/security.h>
  32 #include <linux/swap.h>
  33 #include <linux/syscalls.h>
  34 #include <linux/jiffies.h>
  35 #include <linux/futex.h>
  36 #include <linux/ptrace.h>
  37 #include <linux/mount.h>
  38 #include <linux/audit.h>
  39 #include <linux/rmap.h>
  40 #include <linux/vs_network.h>
  41 #include <linux/vs_limit.h>
  42 #include <linux/vs_memory.h>
  43 #include <linux/ckrm.h>
  44 #include <linux/ckrm_tsk.h>
  45
  46 #include <asm/pgtable.h>
  47 #include <asm/pgalloc.h>
  48 #include <asm/uaccess.h>
  49 #include <asm/mmu_context.h>
  50 #include <asm/cacheflush.h>
  51 #include <asm/tlbflush.h>
  52
  53 /* The idle threads do not count..
  54  * Protected by write_lock_irq(&tasklist_lock)
  55  */
  56 int nr_threads;
  57
  58 int max_threads;
  59 unsigned long total_forks;      /* Handle normal Linux uptimes. */
  60
  61 DEFINE_PER_CPU(unsigned long, process_counts) = 0;
  62
  63 rwlock_t tasklist_lock __cacheline_aligned = RW_LOCK_UNLOCKED;  /* outer */
  64
  65 EXPORT_SYMBOL(tasklist_lock);
  66
  67 int nr_processes(void)
  68 {
  69         int cpu;
  70         int total = 0;
  71
  72         for_each_online_cpu(cpu)
  73                 total += per_cpu(process_counts, cpu);
  74
  75         return total;
  76 }
  77
  78 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
  79 # define alloc_task_struct()    kmem_cache_alloc(task_struct_cachep, GFP_KERNEL)
  80 # define free_task_struct(tsk)  kmem_cache_free(task_struct_cachep, (tsk))
  81 static kmem_cache_t *task_struct_cachep;
  82 #endif
  83
  84 static void free_task(struct task_struct *tsk)
  85 {
  86         free_thread_info(tsk->thread_info);
  87         clr_vx_info(&tsk->vx_info);
  88         clr_nx_info(&tsk->nx_info);
  89         free_task_struct(tsk);
  90 }
  91
  92 void __put_task_struct(struct task_struct *tsk)
  93 {
  94         WARN_ON(!(tsk->state & (TASK_DEAD | TASK_ZOMBIE)));
  95         WARN_ON(atomic_read(&tsk->usage));
  96         WARN_ON(tsk == current);
  97
  98         if (unlikely(tsk->audit_context))
  99                 audit_free(tsk);
 100         security_task_free(tsk);
 101         free_uid(tsk->user);
 102         put_group_info(tsk->group_info);
 103         free_task(tsk);
 104 }
 105
 106 void fastcall add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)
 107 {
 108         unsigned long flags;
 109
 110         wait->flags &= ~WQ_FLAG_EXCLUSIVE;
 111         spin_lock_irqsave(&q->lock, flags);
 112         __add_wait_queue(q, wait);
 113         spin_unlock_irqrestore(&q->lock, flags);
 114 }
 115
 116 EXPORT_SYMBOL(add_wait_queue);
 117
 118 void fastcall add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait)
 119 {
 120         unsigned long flags;
 121
 122         wait->flags |= WQ_FLAG_EXCLUSIVE;
 123         spin_lock_irqsave(&q->lock, flags);
 124         __add_wait_queue_tail(q, wait);
 125         spin_unlock_irqrestore(&q->lock, flags);
 126 }
 127
 128 EXPORT_SYMBOL(add_wait_queue_exclusive);
 129
 130 void fastcall remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)
 131 {
 132         unsigned long flags;
 133
 134         spin_lock_irqsave(&q->lock, flags);
 135         __remove_wait_queue(q, wait);
 136         spin_unlock_irqrestore(&q->lock, flags);
 137 }
 138
 139 EXPORT_SYMBOL(remove_wait_queue);
 140
 141
 142 /*
 143  * Note: we use "set_current_state()" _after_ the wait-queue add,
 144  * because we need a memory barrier there on SMP, so that any
 145  * wake-function that tests for the wait-queue being active
 146  * will be guaranteed to see waitqueue addition _or_ subsequent
 147  * tests in this thread will see the wakeup having taken place.
 148  *
 149  * The spin_unlock() itself is semi-permeable and only protects
 150  * one way (it only protects stuff inside the critical region and
 151  * stops them from bleeding out - it would still allow subsequent
 152  * loads to move into the the critical region).
 153  */
 154 void fastcall prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state)
 155 {
 156         unsigned long flags;
 157
 158         wait->flags &= ~WQ_FLAG_EXCLUSIVE;
 159         spin_lock_irqsave(&q->lock, flags);
 160         if (list_empty(&wait->task_list))
 161                 __add_wait_queue(q, wait);
 162         set_current_state(state);
 163         spin_unlock_irqrestore(&q->lock, flags);
 164 }
 165
 166 EXPORT_SYMBOL(prepare_to_wait);
 167
 168 void fastcall
 169 prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state)
 170 {
 171         unsigned long flags;
 172
 173         wait->flags |= WQ_FLAG_EXCLUSIVE;
 174         spin_lock_irqsave(&q->lock, flags);
 175         if (list_empty(&wait->task_list))
 176                 __add_wait_queue_tail(q, wait);
 177         set_current_state(state);
 178         spin_unlock_irqrestore(&q->lock, flags);
 179 }
 180
 181 EXPORT_SYMBOL(prepare_to_wait_exclusive);
 182
 183 void fastcall finish_wait(wait_queue_head_t *q, wait_queue_t *wait)
 184 {
 185         unsigned long flags;
 186
 187         __set_current_state(TASK_RUNNING);
 188         /*
 189          * We can check for list emptiness outside the lock
 190          * IFF:
 191          *  - we use the "careful" check that verifies both
 192          *    the next and prev pointers, so that there cannot
 193          *    be any half-pending updates in progress on other
 194          *    CPU's that we haven't seen yet (and that might
 195          *    still change the stack area.
 196          * and
 197          *  - all other users take the lock (ie we can only
 198          *    have _one_ other CPU that looks at or modifies
 199          *    the list).
 200          */
 201         if (!list_empty_careful(&wait->task_list)) {
 202                 spin_lock_irqsave(&q->lock, flags);
 203                 list_del_init(&wait->task_list);
 204                 spin_unlock_irqrestore(&q->lock, flags);
 205         }
 206 }
 207
 208 EXPORT_SYMBOL(finish_wait);
 209
 210 int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
 211 {
 212         int ret = default_wake_function(wait, mode, sync, key);
 213
 214         if (ret)
 215                 list_del_init(&wait->task_list);
 216         return ret;
 217 }
 218
 219 EXPORT_SYMBOL(autoremove_wake_function);
 220
 221 void __init fork_init(unsigned long mempages)
 222 {
 223 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
 224 #ifndef ARCH_MIN_TASKALIGN
 225 #define ARCH_MIN_TASKALIGN      L1_CACHE_BYTES
 226 #endif
 227         /* create a slab on which task_structs can be allocated */
 228         task_struct_cachep =
 229                 kmem_cache_create("task_struct", sizeof(struct task_struct),
 230                         ARCH_MIN_TASKALIGN, SLAB_PANIC, NULL, NULL);
 231 #endif
 232
 233         /*
 234          * The default maximum number of threads is set to a safe
 235          * value: the thread structures can take up at most half
 236          * of memory.
 237          */
 238         max_threads = mempages / (THREAD_SIZE/PAGE_SIZE) / 8;
 239         /*
 240          * we need to allow at least 20 threads to boot a system
 241          */
 242         if(max_threads < 20)
 243                 max_threads = 20;
 244
 245         init_task.rlim[RLIMIT_NPROC].rlim_cur = max_threads/2;
 246         init_task.rlim[RLIMIT_NPROC].rlim_max = max_threads/2;
 247 }
 248
 249 static struct task_struct *dup_task_struct(struct task_struct *orig)
 250 {
 251         struct task_struct *tsk;
 252         struct thread_info *ti;
 253
 254         prepare_to_copy(orig);
 255
 256         tsk = alloc_task_struct();
 257         if (!tsk)
 258                 return NULL;
 259
 260         ti = alloc_thread_info(tsk);
 261         if (!ti) {
 262                 free_task_struct(tsk);
 263                 return NULL;
 264         }
 265
 266         *ti = *orig->thread_info;
 267         *tsk = *orig;
 268         tsk->thread_info = ti;
 269         ti->task = tsk;
 270
 271         ckrm_cb_newtask(tsk);
 272         /* One for us, one for whoever does the "release_task()" (usually parent) */
 273         atomic_set(&tsk->usage,2);
 274         return tsk;
 275 }
 276
 277 #ifdef CONFIG_MMU
 278 static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm)
 279 {
 280         struct vm_area_struct * mpnt, *tmp, **pprev;
 281         struct rb_node **rb_link, *rb_parent;
 282         int retval;
 283         unsigned long charge;
 284         struct mempolicy *pol;
 285
 286         down_write(&oldmm->mmap_sem);
 287         flush_cache_mm(current->mm);
 288         mm->locked_vm = 0;
 289         mm->mmap = NULL;
 290         mm->mmap_cache = NULL;
 291         mm->free_area_cache = oldmm->mmap_base;
 292         mm->map_count = 0;
 293         mm->rss = 0;
 294         cpus_clear(mm->cpu_vm_mask);
 295         mm->mm_rb = RB_ROOT;
 296         rb_link = &mm->mm_rb.rb_node;
 297         rb_parent = NULL;
 298         pprev = &mm->mmap;
 299
 300         /*
 301          * Add it to the mmlist after the parent.
 302          * Doing it this way means that we can order the list,
 303          * and fork() won't mess up the ordering significantly.
 304          * Add it first so that swapoff can see any swap entries.
 305          */
 306         spin_lock(&mmlist_lock);
 307         list_add(&mm->mmlist, &current->mm->mmlist);
 308         mmlist_nr++;
 309         spin_unlock(&mmlist_lock);
 310
 311         for (mpnt = current->mm->mmap ; mpnt ; mpnt = mpnt->vm_next) {
 312                 struct file *file;
 313
 314                 if(mpnt->vm_flags & VM_DONTCOPY)
 315                         continue;
 316                 charge = 0;
 317                 if (mpnt->vm_flags & VM_ACCOUNT) {
 318                         unsigned int len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
 319                         if (security_vm_enough_memory(len))
 320                                 goto fail_nomem;
 321                         charge = len;
 322                 }
 323                 tmp = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 324                 if (!tmp)
 325                         goto fail_nomem;
 326                 *tmp = *mpnt;
 327                 pol = mpol_copy(vma_policy(mpnt));
 328                 retval = PTR_ERR(pol);
 329                 if (IS_ERR(pol))
 330                         goto fail_nomem_policy;
 331                 vma_set_policy(tmp, pol);
 332                 tmp->vm_flags &= ~VM_LOCKED;
 333                 tmp->vm_mm = mm;
 334                 tmp->vm_next = NULL;
 335                 anon_vma_link(tmp);
 336                 vma_prio_tree_init(tmp);
 337                 file = tmp->vm_file;
 338                 if (file) {
 339                         struct inode *inode = file->f_dentry->d_inode;
 340                         get_file(file);
 341                         if (tmp->vm_flags & VM_DENYWRITE)
 342                                 atomic_dec(&inode->i_writecount);
 343
 344                         /* insert tmp into the share list, just after mpnt */
 345                         spin_lock(&file->f_mapping->i_mmap_lock);
 346                         flush_dcache_mmap_lock(file->f_mapping);
 347                         vma_prio_tree_add(tmp, mpnt);
 348                         flush_dcache_mmap_unlock(file->f_mapping);
 349                         spin_unlock(&file->f_mapping->i_mmap_lock);
 350                 }
 351
 352                 /*
 353                  * Link in the new vma and copy the page table entries:
 354                  * link in first so that swapoff can see swap entries,
 355                  * and try_to_unmap_one's find_vma find the new vma.
 356                  */
 357                 spin_lock(&mm->page_table_lock);
 358                 *pprev = tmp;
 359                 pprev = &tmp->vm_next;
 360
 361                 __vma_link_rb(mm, tmp, rb_link, rb_parent);
 362                 rb_link = &tmp->vm_rb.rb_right;
 363                 rb_parent = &tmp->vm_rb;
 364
 365                 mm->map_count++;
 366                 retval = copy_page_range(mm, current->mm, tmp);
 367                 spin_unlock(&mm->page_table_lock);
 368
 369                 if (tmp->vm_ops && tmp->vm_ops->open)
 370                         tmp->vm_ops->open(tmp);
 371
 372                 if (retval)
 373                         goto out;
 374         }
 375         retval = 0;
 376
 377 out:
 378         flush_tlb_mm(current->mm);
 379         up_write(&oldmm->mmap_sem);
 380         return retval;
 381 fail_nomem_policy:
 382         kmem_cache_free(vm_area_cachep, tmp);
 383 fail_nomem:
 384         retval = -ENOMEM;
 385         vm_unacct_memory(charge);
 386         goto out;
 387 }
 388
 389 static inline int mm_alloc_pgd(struct mm_struct * mm)
 390 {
 391         mm->pgd = pgd_alloc(mm);
 392         if (unlikely(!mm->pgd))
 393                 return -ENOMEM;
 394         return 0;
 395 }
 396
 397 static inline void mm_free_pgd(struct mm_struct * mm)
 398 {
 399         pgd_free(mm->pgd);
 400 }
 401 #else
 402 #define dup_mmap(mm, oldmm)     (0)
 403 #define mm_alloc_pgd(mm)        (0)
 404 #define mm_free_pgd(mm)
 405 #endif /* CONFIG_MMU */
 406
 407 spinlock_t mmlist_lock __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
 408 int mmlist_nr;
 409
 410 #define allocate_mm()   (kmem_cache_alloc(mm_cachep, SLAB_KERNEL))
 411 #define free_mm(mm)     (kmem_cache_free(mm_cachep, (mm)))
 412
 413 #include <linux/init_task.h>
 414
 415 static struct mm_struct * mm_init(struct mm_struct * mm)
 416 {
 417         atomic_set(&mm->mm_users, 1);
 418         atomic_set(&mm->mm_count, 1);
 419         init_rwsem(&mm->mmap_sem);
 420         mm->core_waiters = 0;
 421         mm->page_table_lock = SPIN_LOCK_UNLOCKED;
 422         mm->ioctx_list_lock = RW_LOCK_UNLOCKED;
 423         mm->ioctx_list = NULL;
 424         mm->default_kioctx = (struct kioctx)INIT_KIOCTX(mm->default_kioctx, *mm);
 425         mm->free_area_cache = TASK_UNMAPPED_BASE;
 426
 427         if (likely(!mm_alloc_pgd(mm))) {
 428                 mm->def_flags = 0;
 429                 set_vx_info(&mm->mm_vx_info, current->vx_info);
 430                 return mm;
 431         }
 432         free_mm(mm);
 433         return NULL;
 434 }
 435
 436 /*
 437  * Allocate and initialize an mm_struct.
 438  */
 439 struct mm_struct * mm_alloc(void)
 440 {
 441         struct mm_struct * mm;
 442
 443         mm = allocate_mm();
 444         if (mm) {
 445                 memset(mm, 0, sizeof(*mm));
 446                 mm = mm_init(mm);
 447         }
 448         return mm;
 449 }
 450
 451 /*
 452  * Called when the last reference to the mm
 453  * is dropped: either by a lazy thread or by
 454  * mmput. Free the page directory and the mm.
 455  */
 456 void fastcall __mmdrop(struct mm_struct *mm)
 457 {
 458         BUG_ON(mm == &init_mm);
 459         mm_free_pgd(mm);
 460         destroy_context(mm);
 461         clr_vx_info(&mm->mm_vx_info);
 462         free_mm(mm);
 463 }
 464
 465 /*
 466  * Decrement the use count and release all resources for an mm.
 467  */
 468 void mmput(struct mm_struct *mm)
 469 {
 470         if (atomic_dec_and_lock(&mm->mm_users, &mmlist_lock)) {
 471                 list_del(&mm->mmlist);
 472                 mmlist_nr--;
 473                 spin_unlock(&mmlist_lock);
 474                 exit_aio(mm);
 475                 exit_mmap(mm);
 476                 put_swap_token(mm);
 477                 mmdrop(mm);
 478         }
 479 }
 480
 481 /*
 482  * Checks if the use count of an mm is non-zero and if so
 483  * returns a reference to it after bumping up the use count.
 484  * If the use count is zero, it means this mm is going away,
 485  * so return NULL.
 486  */
 487 struct mm_struct *mmgrab(struct mm_struct *mm)
 488 {
 489         spin_lock(&mmlist_lock);
 490         if (!atomic_read(&mm->mm_users))
 491                 mm = NULL;
 492         else
 493                 atomic_inc(&mm->mm_users);
 494         spin_unlock(&mmlist_lock);
 495         return mm;
 496 }
 497
 498 /* Please note the differences between mmput and mm_release.
 499  * mmput is called whenever we stop holding onto a mm_struct,
 500  * error success whatever.
 501  *
 502  * mm_release is called after a mm_struct has been removed
 503  * from the current process.
 504  *
 505  * This difference is important for error handling, when we
 506  * only half set up a mm_struct for a new process and need to restore
 507  * the old one.  Because we mmput the new mm_struct before
 508  * restoring the old one. . .
 509  * Eric Biederman 10 January 1998
 510  */
 511 void mm_release(struct task_struct *tsk, struct mm_struct *mm)
 512 {
 513         struct completion *vfork_done = tsk->vfork_done;
 514
 515         /* Get rid of any cached register state */
 516         deactivate_mm(tsk, mm);
 517
 518         /* notify parent sleeping on vfork() */
 519         if (vfork_done) {
 520                 tsk->vfork_done = NULL;
 521                 complete(vfork_done);
 522         }
 523         if (tsk->clear_child_tid && atomic_read(&mm->mm_users) > 1) {
 524                 u32 __user * tidptr = tsk->clear_child_tid;
 525                 tsk->clear_child_tid = NULL;
 526
 527                 /*
 528                  * We don't check the error code - if userspace has
 529                  * not set up a proper pointer then tough luck.
 530                  */
 531                 put_user(0, tidptr);
 532                 sys_futex(tidptr, FUTEX_WAKE, 1, NULL, NULL, 0);
 533         }
 534 }
 535
 536 static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
 537 {
 538         struct mm_struct * mm, *oldmm;
 539         int retval;
 540
 541         tsk->min_flt = tsk->maj_flt = 0;
 542         tsk->cmin_flt = tsk->cmaj_flt = 0;
 543         tsk->nvcsw = tsk->nivcsw = tsk->cnvcsw = tsk->cnivcsw = 0;
 544
 545         tsk->mm = NULL;
 546         tsk->active_mm = NULL;
 547
 548         /*
 549          * Are we cloning a kernel thread?
 550          *
 551          * We need to steal a active VM for that..
 552          */
 553         oldmm = current->mm;
 554         if (!oldmm)
 555                 return 0;
 556
 557         if (clone_flags & CLONE_VM) {
 558                 atomic_inc(&oldmm->mm_users);
 559                 mm = oldmm;
 560                 /*
 561                  * There are cases where the PTL is held to ensure no
 562                  * new threads start up in user mode using an mm, which
 563                  * allows optimizing out ipis; the tlb_gather_mmu code
 564                  * is an example.
 565                  */
 566                 spin_unlock_wait(&oldmm->page_table_lock);
 567                 goto good_mm;
 568         }
 569
 570         retval = -ENOMEM;
 571         mm = allocate_mm();
 572         if (!mm)
 573                 goto fail_nomem;
 574
 575         /* Copy the current MM stuff.. */
 576         memcpy(mm, oldmm, sizeof(*mm));
 577         mm->mm_vx_info = NULL;
 578         if (!mm_init(mm))
 579                 goto fail_nomem;
 580
 581         if (init_new_context(tsk,mm))
 582                 goto fail_nocontext;
 583
 584         retval = dup_mmap(mm, oldmm);
 585         if (retval)
 586                 goto free_pt;
 587
 588 good_mm:
 589         tsk->mm = mm;
 590         tsk->active_mm = mm;
 591         return 0;
 592
 593 free_pt:
 594         mmput(mm);
 595 fail_nomem:
 596         return retval;
 597
 598 fail_nocontext:
 599         /*
 600          * If init_new_context() failed, we cannot use mmput() to free the mm
 601          * because it calls destroy_context()
 602          */
 603         mm_free_pgd(mm);
 604         free_mm(mm);
 605         return retval;
 606 }
 607
 608 static inline struct fs_struct *__copy_fs_struct(struct fs_struct *old)
 609 {
 610         struct fs_struct *fs = kmem_cache_alloc(fs_cachep, GFP_KERNEL);
 611         /* We don't need to lock fs - think why ;-) */
 612         if (fs) {
 613                 atomic_set(&fs->count, 1);
 614                 fs->lock = RW_LOCK_UNLOCKED;
 615                 fs->umask = old->umask;
 616                 read_lock(&old->lock);
 617                 fs->rootmnt = mntget(old->rootmnt);
 618                 fs->root = dget(old->root);
 619                 fs->pwdmnt = mntget(old->pwdmnt);
 620                 fs->pwd = dget(old->pwd);
 621                 if (old->altroot) {
 622                         fs->altrootmnt = mntget(old->altrootmnt);
 623                         fs->altroot = dget(old->altroot);
 624                 } else {
 625                         fs->altrootmnt = NULL;
 626                         fs->altroot = NULL;
 627                 }
 628                 read_unlock(&old->lock);
 629         }
 630         return fs;
 631 }
 632
 633 struct fs_struct *copy_fs_struct(struct fs_struct *old)
 634 {
 635         return __copy_fs_struct(old);
 636 }
 637
 638 EXPORT_SYMBOL_GPL(copy_fs_struct);
 639
 640 static inline int copy_fs(unsigned long clone_flags, struct task_struct * tsk)
 641 {
 642         if (clone_flags & CLONE_FS) {
 643                 atomic_inc(&current->fs->count);
 644                 return 0;
 645         }
 646         tsk->fs = __copy_fs_struct(current->fs);
 647         if (!tsk->fs)
 648                 return -ENOMEM;
 649         return 0;
 650 }
 651
 652 static int count_open_files(struct files_struct *files, int size)
 653 {
 654         int i;
 655
 656         /* Find the last open fd */
 657         for (i = size/(8*sizeof(long)); i > 0; ) {
 658                 if (files->open_fds->fds_bits[--i])
 659                         break;
 660         }
 661         i = (i+1) * 8 * sizeof(long);
 662         return i;
 663 }
 664
 665 static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
 666 {
 667         struct files_struct *oldf, *newf;
 668         struct file **old_fds, **new_fds;
 669         int open_files, nfds, size, i, error = 0;
 670
 671         /*
 672          * A background process may not have any files ...
 673          */
 674         oldf = current->files;
 675         if (!oldf)
 676                 goto out;
 677
 678         if (clone_flags & CLONE_FILES) {
 679                 atomic_inc(&oldf->count);
 680                 goto out;
 681         }
 682
 683         /*
 684          * Note: we may be using current for both targets (See exec.c)
 685          * This works because we cache current->files (old) as oldf. Don't
 686          * break this.
 687          */
 688         tsk->files = NULL;
 689         error = -ENOMEM;
 690         newf = kmem_cache_alloc(files_cachep, SLAB_KERNEL);
 691         if (!newf)
 692                 goto out;
 693
 694         atomic_set(&newf->count, 1);
 695
 696         newf->file_lock     = SPIN_LOCK_UNLOCKED;
 697         newf->next_fd       = 0;
 698         newf->max_fds       = NR_OPEN_DEFAULT;
 699         newf->max_fdset     = __FD_SETSIZE;
 700         newf->close_on_exec = &newf->close_on_exec_init;
 701         newf->open_fds      = &newf->open_fds_init;
 702         newf->fd            = &newf->fd_array[0];
 703
 704         /* We don't yet have the oldf readlock, but even if the old
 705            fdset gets grown now, we'll only copy up to "size" fds */
 706         size = oldf->max_fdset;
 707         if (size > __FD_SETSIZE) {
 708                 newf->max_fdset = 0;
 709                 spin_lock(&newf->file_lock);
 710                 error = expand_fdset(newf, size-1);
 711                 spin_unlock(&newf->file_lock);
 712                 if (error)
 713                         goto out_release;
 714         }
 715         spin_lock(&oldf->file_lock);
 716
 717         open_files = count_open_files(oldf, size);
 718
 719         /*
 720          * Check whether we need to allocate a larger fd array.
 721          * Note: we're not a clone task, so the open count won't
 722          * change.
 723          */
 724         nfds = NR_OPEN_DEFAULT;
 725         if (open_files > nfds) {
 726                 spin_unlock(&oldf->file_lock);
 727                 newf->max_fds = 0;
 728                 spin_lock(&newf->file_lock);
 729                 error = expand_fd_array(newf, open_files-1);
 730                 spin_unlock(&newf->file_lock);
 731                 if (error)
 732                         goto out_release;
 733                 nfds = newf->max_fds;
 734                 spin_lock(&oldf->file_lock);
 735         }
 736
 737         old_fds = oldf->fd;
 738         new_fds = newf->fd;
 739
 740         memcpy(newf->open_fds->fds_bits, oldf->open_fds->fds_bits, open_files/8);
 741         memcpy(newf->close_on_exec->fds_bits, oldf->close_on_exec->fds_bits, open_files/8);
 742
 743         for (i = open_files; i != 0; i--) {
 744                 struct file *f = *old_fds++;
 745                 if (f)
 746                         get_file(f);
 747                 *new_fds++ = f;
 748         }
 749         spin_unlock(&oldf->file_lock);
 750
 751         /* compute the remainder to be cleared */
 752         size = (newf->max_fds - open_files) * sizeof(struct file *);
 753
 754         /* This is long word aligned thus could use a optimized version */
 755         memset(new_fds, 0, size);
 756
 757         if (newf->max_fdset > open_files) {
 758                 int left = (newf->max_fdset-open_files)/8;
 759                 int start = open_files / (8 * sizeof(unsigned long));
 760
 761                 memset(&newf->open_fds->fds_bits[start], 0, left);
 762                 memset(&newf->close_on_exec->fds_bits[start], 0, left);
 763         }
 764
 765         tsk->files = newf;
 766         error = 0;
 767 out:
 768         return error;
 769
 770 out_release:
 771         free_fdset (newf->close_on_exec, newf->max_fdset);
 772         free_fdset (newf->open_fds, newf->max_fdset);
 773         kmem_cache_free(files_cachep, newf);
 774         goto out;
 775 }
 776
 777 /*
 778  *      Helper to unshare the files of the current task.
 779  *      We don't want to expose copy_files internals to
 780  *      the exec layer of the kernel.
 781  */
 782
 783 int unshare_files(void)
 784 {
 785         struct files_struct *files  = current->files;
 786         int rc;
 787
 788         if(!files)
 789                 BUG();
 790
 791         /* This can race but the race causes us to copy when we don't
 792            need to and drop the copy */
 793         if(atomic_read(&files->count) == 1)
 794         {
 795                 atomic_inc(&files->count);
 796                 return 0;
 797         }
 798         rc = copy_files(0, current);
 799         if(rc)
 800                 current->files = files;
 801         return rc;
 802 }
 803
 804 EXPORT_SYMBOL(unshare_files);
 805
 806 static inline int copy_sighand(unsigned long clone_flags, struct task_struct * tsk)
 807 {
 808         struct sighand_struct *sig;
 809
 810         if (clone_flags & (CLONE_SIGHAND | CLONE_THREAD)) {
 811                 atomic_inc(&current->sighand->count);
 812                 return 0;
 813         }
 814         sig = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
 815         tsk->sighand = sig;
 816         if (!sig)
 817                 return -ENOMEM;
 818         spin_lock_init(&sig->siglock);
 819         atomic_set(&sig->count, 1);
 820         memcpy(sig->action, current->sighand->action, sizeof(sig->action));
 821         return 0;
 822 }
 823
 824 static inline int copy_signal(unsigned long clone_flags, struct task_struct * tsk)
 825 {
 826         struct signal_struct *sig;
 827
 828         if (clone_flags & CLONE_THREAD) {
 829                 atomic_inc(&current->signal->count);
 830                 return 0;
 831         }
 832         sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
 833         tsk->signal = sig;
 834         if (!sig)
 835                 return -ENOMEM;
 836         atomic_set(&sig->count, 1);
 837         sig->group_exit = 0;
 838         sig->group_exit_code = 0;
 839         sig->group_exit_task = NULL;
 840         sig->group_stop_count = 0;
 841         sig->curr_target = NULL;
 842         init_sigpending(&sig->shared_pending);
 843         INIT_LIST_HEAD(&sig->posix_timers);
 844
 845         sig->tty = current->signal->tty;
 846         sig->pgrp = process_group(current);
 847         sig->session = current->signal->session;
 848         sig->leader = 0;        /* session leadership doesn't inherit */
 849         sig->tty_old_pgrp = 0;
 850
 851         return 0;
 852 }
 853
 854 static inline void copy_flags(unsigned long clone_flags, struct task_struct *p)
 855 {
 856         unsigned long new_flags = p->flags;
 857
 858         new_flags &= ~PF_SUPERPRIV;
 859         new_flags |= PF_FORKNOEXEC;
 860         if (!(clone_flags & CLONE_PTRACE))
 861                 p->ptrace = 0;
 862         p->flags = new_flags;
 863 }
 864
 865 asmlinkage long sys_set_tid_address(int __user *tidptr)
 866 {
 867         current->clear_child_tid = tidptr;
 868
 869         return current->pid;
 870 }
 871
 872 /*
 873  * This creates a new process as a copy of the old one,
 874  * but does not actually start it yet.
 875  *
 876  * It copies the registers, and all the appropriate
 877  * parts of the process environment (as per the clone
 878  * flags). The actual kick-off is left to the caller.
 879  */
 880 struct task_struct *copy_process(unsigned long clone_flags,
 881                                  unsigned long stack_start,
 882                                  struct pt_regs *regs,
 883                                  unsigned long stack_size,
 884                                  int __user *parent_tidptr,
 885                                  int __user *child_tidptr)
 886 {
 887         int retval;
 888         struct task_struct *p = NULL;
 889         struct vx_info *vxi;
 890
 891         if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
 892                 return ERR_PTR(-EINVAL);
 893
 894         /*
 895          * Thread groups must share signals as well, and detached threads
 896          * can only be started up within the thread group.
 897          */
 898         if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
 899                 return ERR_PTR(-EINVAL);
 900
 901         /*
 902          * Shared signal handlers imply shared VM. By way of the above,
 903          * thread groups also imply shared VM. Blocking this case allows
 904          * for various simplifications in other code.
 905          */
 906         if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
 907                 return ERR_PTR(-EINVAL);
 908
 909         retval = security_task_create(clone_flags);
 910         if (retval)
 911                 goto fork_out;
 912
 913         retval = -ENOMEM;
 914         p = dup_task_struct(current);
 915         if (!p)
 916                 goto fork_out;
 917         p->tux_info = NULL;
 918
 919         p->vx_info = NULL;
 920         set_vx_info(&p->vx_info, current->vx_info);
 921         p->nx_info = NULL;
 922         set_nx_info(&p->nx_info, current->nx_info);
 923
 924         /* check vserver memory */
 925         if (p->mm && !(clone_flags & CLONE_VM)) {
 926                 if (vx_vmpages_avail(p->mm, p->mm->total_vm))
 927                         vx_pages_add(p->mm->mm_vx_info, RLIMIT_AS, p->mm->total_vm);
 928                 else
 929                         goto bad_fork_free;
 930         }
 931         if (p->mm && vx_flags(VXF_FORK_RSS, 0)) {
 932                 if (!vx_rsspages_avail(p->mm, p->mm->rss))
 933                         goto bad_fork_cleanup_vm;
 934         }
 935
 936         retval = -EAGAIN;
 937         if (!vx_nproc_avail(1))
 938                 goto bad_fork_cleanup_vm;
 939
 940         if (atomic_read(&p->user->processes) >=
 941                         p->rlim[RLIMIT_NPROC].rlim_cur) {
 942                 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
 943                                 p->user != &root_user)
 944                         goto bad_fork_cleanup_vm;
 945         }
 946
 947         atomic_inc(&p->user->__count);
 948         atomic_inc(&p->user->processes);
 949         get_group_info(p->group_info);
 950
 951         /*
 952          * If multiple threads are within copy_process(), then this check
 953          * triggers too late. This doesn't hurt, the check is only there
 954          * to stop root fork bombs.
 955          */
 956         if (nr_threads >= max_threads)
 957                 goto bad_fork_cleanup_count;
 958
 959         if (!try_module_get(p->thread_info->exec_domain->module))
 960                 goto bad_fork_cleanup_count;
 961
 962         if (p->binfmt && !try_module_get(p->binfmt->module))
 963                 goto bad_fork_cleanup_put_domain;
 964
 965         init_delays(p);
 966         p->did_exec = 0;
 967         copy_flags(clone_flags, p);
 968         if (clone_flags & CLONE_IDLETASK)
 969                 p->pid = 0;
 970         else {
 971                 p->pid = alloc_pidmap();
 972                 if (p->pid == -1)
 973                         goto bad_fork_cleanup;
 974         }
 975         retval = -EFAULT;
 976         if (clone_flags & CLONE_PARENT_SETTID)
 977                 if (put_user(p->pid, parent_tidptr))
 978                         goto bad_fork_cleanup;
 979
 980         p->proc_dentry = NULL;
 981
 982         INIT_LIST_HEAD(&p->children);
 983         INIT_LIST_HEAD(&p->sibling);
 984         init_waitqueue_head(&p->wait_chldexit);
 985         p->vfork_done = NULL;
 986         spin_lock_init(&p->alloc_lock);
 987         spin_lock_init(&p->proc_lock);
 988
 989         clear_tsk_thread_flag(p, TIF_SIGPENDING);
 990         init_sigpending(&p->pending);
 991
 992         p->it_real_value = p->it_virt_value = p->it_prof_value = 0;
 993         p->it_real_incr = p->it_virt_incr = p->it_prof_incr = 0;
 994         init_timer(&p->real_timer);
 995         p->real_timer.data = (unsigned long) p;
 996
 997         p->utime = p->stime = 0;
 998         p->cutime = p->cstime = 0;
 999         p->lock_depth = -1;             /* -1 = no lock */
1000         p->start_time = get_jiffies_64();
1001         p->security = NULL;
1002         p->io_context = NULL;
1003         p->audit_context = NULL;
1004 #ifdef CONFIG_NUMA
1005         p->mempolicy = mpol_copy(p->mempolicy);
1006         if (IS_ERR(p->mempolicy)) {
1007                 retval = PTR_ERR(p->mempolicy);
1008                 p->mempolicy = NULL;
1009                 goto bad_fork_cleanup;
1010         }
1011 #endif
1012
1013         if ((retval = security_task_alloc(p)))
1014                 goto bad_fork_cleanup_policy;
1015         if ((retval = audit_alloc(p)))
1016                 goto bad_fork_cleanup_security;
1017         /* copy all the process information */
1018         if ((retval = copy_semundo(clone_flags, p)))
1019                 goto bad_fork_cleanup_audit;
1020         if ((retval = copy_files(clone_flags, p)))
1021                 goto bad_fork_cleanup_semundo;
1022         if ((retval = copy_fs(clone_flags, p)))
1023                 goto bad_fork_cleanup_files;
1024         if ((retval = copy_sighand(clone_flags, p)))
1025                 goto bad_fork_cleanup_fs;
1026         if ((retval = copy_signal(clone_flags, p)))
1027                 goto bad_fork_cleanup_sighand;
1028         if ((retval = copy_mm(clone_flags, p)))
1029                 goto bad_fork_cleanup_signal;
1030         if ((retval = copy_namespace(clone_flags, p)))
1031                 goto bad_fork_cleanup_mm;
1032         retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
1033         if (retval)
1034                 goto bad_fork_cleanup_namespace;
1035
1036         p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
1037         /*
1038          * Clear TID on mm_release()?
1039          */
1040         p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
1041
1042         /*
1043          * Syscall tracing should be turned off in the child regardless
1044          * of CLONE_PTRACE.
1045          */
1046         clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
1047
1048         /* Our parent execution domain becomes current domain
1049            These must match for thread signalling to apply */
1050
1051         p->parent_exec_id = p->self_exec_id;
1052
1053         /* ok, now we should be set up.. */
1054         p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
1055         p->pdeath_signal = 0;
1056
1057         /* Perform scheduler related setup */
1058         sched_fork(p);
1059
1060         /*
1061          * Ok, make it visible to the rest of the system.
1062          * We dont wake it up yet.
1063          */
1064         p->tgid = p->pid;
1065         p->group_leader = p;
1066         INIT_LIST_HEAD(&p->ptrace_children);
1067         INIT_LIST_HEAD(&p->ptrace_list);
1068
1069         /* Need tasklist lock for parent etc handling! */
1070         write_lock_irq(&tasklist_lock);
1071         /*
1072          * Check for pending SIGKILL! The new thread should not be allowed
1073          * to slip out of an OOM kill. (or normal SIGKILL.)
1074          */
1075         if (sigismember(&current->pending.signal, SIGKILL)) {
1076                 write_unlock_irq(&tasklist_lock);
1077                 retval = -EINTR;
1078                 goto bad_fork_cleanup_namespace;
1079         }
1080
1081         /* CLONE_PARENT re-uses the old parent */
1082         if (clone_flags & CLONE_PARENT)
1083                 p->real_parent = current->real_parent;
1084         else
1085                 p->real_parent = current;
1086         p->parent = p->real_parent;
1087
1088         if (clone_flags & CLONE_THREAD) {
1089                 spin_lock(&current->sighand->siglock);
1090                 /*
1091                  * Important: if an exit-all has been started then
1092                  * do not create this new thread - the whole thread
1093                  * group is supposed to exit anyway.
1094                  */
1095                 if (current->signal->group_exit) {
1096                         spin_unlock(&current->sighand->siglock);
1097                         write_unlock_irq(&tasklist_lock);
1098                         retval = -EAGAIN;
1099                         goto bad_fork_cleanup_namespace;
1100                 }
1101                 p->tgid = current->tgid;
1102                 p->group_leader = current->group_leader;
1103
1104                 if (current->signal->group_stop_count > 0) {
1105                         /*
1106                          * There is an all-stop in progress for the group.
1107                          * We ourselves will stop as soon as we check signals.
1108                          * Make the new thread part of that group stop too.
1109                          */
1110                         current->signal->group_stop_count++;
1111                         set_tsk_thread_flag(p, TIF_SIGPENDING);
1112                 }
1113
1114                 spin_unlock(&current->sighand->siglock);
1115         }
1116
1117         SET_LINKS(p);
1118         if (p->ptrace & PT_PTRACED)
1119                 __ptrace_link(p, current->parent);
1120
1121         attach_pid(p, PIDTYPE_PID, p->pid);
1122         if (thread_group_leader(p)) {
1123                 attach_pid(p, PIDTYPE_TGID, p->tgid);
1124                 attach_pid(p, PIDTYPE_PGID, process_group(p));
1125                 attach_pid(p, PIDTYPE_SID, p->signal->session);
1126                 if (p->pid)
1127                         __get_cpu_var(process_counts)++;
1128         } else
1129                 link_pid(p, p->pids + PIDTYPE_TGID, &p->group_leader->pids[PIDTYPE_TGID].pid);
1130
1131         nr_threads++;
1132         /* p is copy of current */
1133         vxi = p->vx_info;
1134         if (vxi) {
1135                 atomic_inc(&vxi->cacct.nr_threads);
1136                 atomic_inc(&vxi->limit.rcur[RLIMIT_NPROC]);
1137         }
1138         write_unlock_irq(&tasklist_lock);
1139         retval = 0;
1140
1141 fork_out:
1142         if (retval)
1143                 return ERR_PTR(retval);
1144         return p;
1145
1146 bad_fork_cleanup_namespace:
1147         exit_namespace(p);
1148 bad_fork_cleanup_mm:
1149         exit_mm(p);
1150         if (p->active_mm)
1151                 mmdrop(p->active_mm);
1152 bad_fork_cleanup_signal:
1153         exit_signal(p);
1154 bad_fork_cleanup_sighand:
1155         exit_sighand(p);
1156 bad_fork_cleanup_fs:
1157         exit_fs(p); /* blocking */
1158 bad_fork_cleanup_files:
1159         exit_files(p); /* blocking */
1160 bad_fork_cleanup_semundo:
1161         exit_sem(p);
1162 bad_fork_cleanup_audit:
1163         audit_free(p);
1164 bad_fork_cleanup_security:
1165         security_task_free(p);
1166 bad_fork_cleanup_policy:
1167 #ifdef CONFIG_NUMA
1168         mpol_free(p->mempolicy);
1169 #endif
1170 bad_fork_cleanup:
1171         if (p->pid > 0)
1172                 free_pidmap(p->pid);
1173         if (p->binfmt)
1174                 module_put(p->binfmt->module);
1175 bad_fork_cleanup_put_domain:
1176         module_put(p->thread_info->exec_domain->module);
1177 bad_fork_cleanup_count:
1178         put_group_info(p->group_info);
1179         atomic_dec(&p->user->processes);
1180         free_uid(p->user);
1181 bad_fork_cleanup_vm:
1182         if (p->mm && !(clone_flags & CLONE_VM))
1183                 vx_pages_sub(p->mm->mm_vx_info, RLIMIT_AS, p->mm->total_vm);
1184 bad_fork_free:
1185         free_task(p);
1186         goto fork_out;
1187 }
1188
1189 static inline int fork_traceflag (unsigned clone_flags)
1190 {
1191         if (clone_flags & (CLONE_UNTRACED | CLONE_IDLETASK))
1192                 return 0;
1193         else if (clone_flags & CLONE_VFORK) {
1194                 if (current->ptrace & PT_TRACE_VFORK)
1195                         return PTRACE_EVENT_VFORK;
1196         } else if ((clone_flags & CSIGNAL) != SIGCHLD) {
1197                 if (current->ptrace & PT_TRACE_CLONE)
1198                         return PTRACE_EVENT_CLONE;
1199         } else if (current->ptrace & PT_TRACE_FORK)
1200                 return PTRACE_EVENT_FORK;
1201
1202         return 0;
1203 }
1204
1205 /*
1206  *  Ok, this is the main fork-routine.
1207  *
1208  * It copies the process, and if successful kick-starts
1209  * it and waits for it to finish using the VM if required.
1210  */
1211 long do_fork(unsigned long clone_flags,
1212               unsigned long stack_start,
1213               struct pt_regs *regs,
1214               unsigned long stack_size,
1215               int __user *parent_tidptr,
1216               int __user *child_tidptr)
1217 {
1218         struct task_struct *p;
1219         int trace = 0;
1220         long pid;
1221
1222         if (unlikely(current->ptrace)) {
1223                 trace = fork_traceflag (clone_flags);
1224                 if (trace)
1225                         clone_flags |= CLONE_PTRACE;
1226         }
1227
1228 #ifdef CONFIG_CKRM_TYPE_TASKCLASS
1229         if (numtasks_get_ref(current->taskclass, 0) == 0) {
1230                 return -ENOMEM;
1231         }
1232 #endif
1233
1234         p = copy_process(clone_flags, stack_start, regs, stack_size, parent_tidptr, child_tidptr);
1235         /*
1236          * Do this prior waking up the new thread - the thread pointer
1237          * might get invalid after that point, if the thread exits quickly.
1238          */
1239         pid = IS_ERR(p) ? PTR_ERR(p) : p->pid;
1240
1241         if (!IS_ERR(p)) {
1242                 struct completion vfork;
1243
1244                 ckrm_cb_fork(p);
1245
1246                 if (clone_flags & CLONE_VFORK) {
1247                         p->vfork_done = &vfork;
1248                         init_completion(&vfork);
1249                 }
1250
1251                 if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) {
1252                         /*
1253                          * We'll start up with an immediate SIGSTOP.
1254                          */
1255                         sigaddset(&p->pending.signal, SIGSTOP);
1256                         set_tsk_thread_flag(p, TIF_SIGPENDING);
1257                 }
1258
1259                 if (!(clone_flags & CLONE_STOPPED)) {
1260                         /*
1261                          * Do the wakeup last. On SMP we treat fork() and
1262                          * CLONE_VM separately, because fork() has already
1263                          * created cache footprint on this CPU (due to
1264                          * copying the pagetables), hence migration would
1265                          * probably be costy. Threads on the other hand
1266                          * have less traction to the current CPU, and if
1267                          * there's an imbalance then the scheduler can
1268                          * migrate this fresh thread now, before it
1269                          * accumulates a larger cache footprint:
1270                          */
1271                         if (clone_flags & CLONE_VM)
1272                                 wake_up_forked_thread(p);
1273                         else
1274                                 wake_up_forked_process(p);
1275                 } else {
1276                         int cpu = get_cpu();
1277
1278                         p->state = TASK_STOPPED;
1279                         if (cpu_is_offline(task_cpu(p)))
1280                                 set_task_cpu(p, cpu);
1281
1282                         put_cpu();
1283                 }
1284                 ++total_forks;
1285
1286                 if (unlikely (trace)) {
1287                         current->ptrace_message = pid;
1288                         ptrace_notify ((trace << 8) | SIGTRAP);
1289                 }
1290
1291                 if (clone_flags & CLONE_VFORK) {
1292                         wait_for_completion(&vfork);
1293                         if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE))
1294                                 ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
1295                 } else
1296                         /*
1297                          * Let the child process run first, to avoid most of the
1298                          * COW overhead when the child exec()s afterwards.
1299                          */
1300                         set_need_resched();
1301         } else {
1302 #ifdef CONFIG_CKRM_TYPE_TASKCLASS
1303                 numtasks_put_ref(current->taskclass);
1304 #endif
1305         }
1306         return pid;
1307 }
1308
1309 /* SLAB cache for signal_struct structures (tsk->signal) */
1310 kmem_cache_t *signal_cachep;
1311
1312 /* SLAB cache for sighand_struct structures (tsk->sighand) */
1313 kmem_cache_t *sighand_cachep;
1314
1315 /* SLAB cache for files_struct structures (tsk->files) */
1316 kmem_cache_t *files_cachep;
1317
1318 /* SLAB cache for fs_struct structures (tsk->fs) */
1319 kmem_cache_t *fs_cachep;
1320
1321 /* SLAB cache for vm_area_struct structures */
1322 kmem_cache_t *vm_area_cachep;
1323
1324 /* SLAB cache for mm_struct structures (tsk->mm) */
1325 kmem_cache_t *mm_cachep;
1326
1327 void __init proc_caches_init(void)
1328 {
1329         sighand_cachep = kmem_cache_create("sighand_cache",
1330                         sizeof(struct sighand_struct), 0,
1331                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1332         signal_cachep = kmem_cache_create("signal_cache",
1333                         sizeof(struct signal_struct), 0,
1334                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1335         files_cachep = kmem_cache_create("files_cache",
1336                         sizeof(struct files_struct), 0,
1337                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1338         fs_cachep = kmem_cache_create("fs_cache",
1339                         sizeof(struct fs_struct), 0,
1340                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1341         vm_area_cachep = kmem_cache_create("vm_area_struct",
1342                         sizeof(struct vm_area_struct), 0,
1343                         SLAB_PANIC, NULL, NULL);
1344         mm_cachep = kmem_cache_create("mm_struct",
1345                         sizeof(struct mm_struct), 0,
1346                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1347 }