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/profile.h>
  40 #include <linux/rmap.h>
  41 #include <linux/vs_network.h>
  42 #include <linux/vs_limit.h>
  43 #include <linux/vs_memory.h>
  44 #include <linux/ckrm.h>
  45 #include <linux/ckrm_tsk.h>
  46 #include <linux/ckrm_mem_inline.h>
  47
  48 #include <asm/pgtable.h>
  49 #include <asm/pgalloc.h>
  50 #include <asm/uaccess.h>
  51 #include <asm/mmu_context.h>
  52 #include <asm/cacheflush.h>
  53 #include <asm/tlbflush.h>
  54
  55 /* The idle threads do not count..
  56  * Protected by write_lock_irq(&tasklist_lock)
  57  */
  58 int nr_threads;
  59
  60 int max_threads;
  61 unsigned long total_forks;      /* Handle normal Linux uptimes. */
  62
  63 DEFINE_PER_CPU(unsigned long, process_counts) = 0;
  64
  65 rwlock_t tasklist_lock __cacheline_aligned = RW_LOCK_UNLOCKED;  /* outer */
  66
  67 EXPORT_SYMBOL(tasklist_lock);
  68
  69 int nr_processes(void)
  70 {
  71         int cpu;
  72         int total = 0;
  73
  74         for_each_online_cpu(cpu)
  75                 total += per_cpu(process_counts, cpu);
  76
  77         return total;
  78 }
  79
  80 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
  81 # define alloc_task_struct()    kmem_cache_alloc(task_struct_cachep, GFP_KERNEL)
  82 # define free_task_struct(tsk)  kmem_cache_free(task_struct_cachep, (tsk))
  83 static kmem_cache_t *task_struct_cachep;
  84 #endif
  85
  86 void free_task(struct task_struct *tsk)
  87 {
  88         free_thread_info(tsk->thread_info);
  89         clr_vx_info(&tsk->vx_info);
  90         clr_nx_info(&tsk->nx_info);
  91         free_task_struct(tsk);
  92 }
  93 EXPORT_SYMBOL(free_task);
  94
  95 void __put_task_struct(struct task_struct *tsk)
  96 {
  97         WARN_ON(!(tsk->exit_state & (EXIT_DEAD | EXIT_ZOMBIE)));
  98         WARN_ON(atomic_read(&tsk->usage));
  99         WARN_ON(tsk == current);
 100
 101         if (unlikely(tsk->audit_context))
 102                 audit_free(tsk);
 103         security_task_free(tsk);
 104         free_uid(tsk->user);
 105         put_group_info(tsk->group_info);
 106
 107         if (!profile_handoff_task(tsk))
 108                 free_task(tsk);
 109 }
 110
 111 void fastcall add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)
 112 {
 113         unsigned long flags;
 114
 115         wait->flags &= ~WQ_FLAG_EXCLUSIVE;
 116         spin_lock_irqsave(&q->lock, flags);
 117         __add_wait_queue(q, wait);
 118         spin_unlock_irqrestore(&q->lock, flags);
 119 }
 120
 121 EXPORT_SYMBOL(add_wait_queue);
 122
 123 void fastcall add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait)
 124 {
 125         unsigned long flags;
 126
 127         wait->flags |= WQ_FLAG_EXCLUSIVE;
 128         spin_lock_irqsave(&q->lock, flags);
 129         __add_wait_queue_tail(q, wait);
 130         spin_unlock_irqrestore(&q->lock, flags);
 131 }
 132
 133 EXPORT_SYMBOL(add_wait_queue_exclusive);
 134
 135 void fastcall remove_wait_queue(wait_queue_head_t *q, wait_queue_t * wait)
 136 {
 137         unsigned long flags;
 138
 139         spin_lock_irqsave(&q->lock, flags);
 140         __remove_wait_queue(q, wait);
 141         spin_unlock_irqrestore(&q->lock, flags);
 142 }
 143
 144 EXPORT_SYMBOL(remove_wait_queue);
 145
 146
 147 /*
 148  * Note: we use "set_current_state()" _after_ the wait-queue add,
 149  * because we need a memory barrier there on SMP, so that any
 150  * wake-function that tests for the wait-queue being active
 151  * will be guaranteed to see waitqueue addition _or_ subsequent
 152  * tests in this thread will see the wakeup having taken place.
 153  *
 154  * The spin_unlock() itself is semi-permeable and only protects
 155  * one way (it only protects stuff inside the critical region and
 156  * stops them from bleeding out - it would still allow subsequent
 157  * loads to move into the the critical region).
 158  */
 159 void fastcall prepare_to_wait(wait_queue_head_t *q, wait_queue_t *wait, int state)
 160 {
 161         unsigned long flags;
 162
 163         wait->flags &= ~WQ_FLAG_EXCLUSIVE;
 164         spin_lock_irqsave(&q->lock, flags);
 165         if (list_empty(&wait->task_list))
 166                 __add_wait_queue(q, wait);
 167         /*
 168          * don't alter the task state if this is just going to
 169          * queue an async wait queue callback
 170          */
 171         if (is_sync_wait(wait))
 172                 set_current_state(state);
 173         spin_unlock_irqrestore(&q->lock, flags);
 174 }
 175
 176 EXPORT_SYMBOL(prepare_to_wait);
 177
 178 void fastcall
 179 prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int state)
 180 {
 181         unsigned long flags;
 182
 183         wait->flags |= WQ_FLAG_EXCLUSIVE;
 184         spin_lock_irqsave(&q->lock, flags);
 185         if (list_empty(&wait->task_list))
 186                 __add_wait_queue_tail(q, wait);
 187         /*
 188          * don't alter the task state if this is just going to
 189          * queue an async wait queue callback
 190          */
 191         if (is_sync_wait(wait))
 192                 set_current_state(state);
 193         spin_unlock_irqrestore(&q->lock, flags);
 194 }
 195
 196 EXPORT_SYMBOL(prepare_to_wait_exclusive);
 197
 198 void fastcall finish_wait(wait_queue_head_t *q, wait_queue_t *wait)
 199 {
 200         unsigned long flags;
 201
 202         __set_current_state(TASK_RUNNING);
 203         /*
 204          * We can check for list emptiness outside the lock
 205          * IFF:
 206          *  - we use the "careful" check that verifies both
 207          *    the next and prev pointers, so that there cannot
 208          *    be any half-pending updates in progress on other
 209          *    CPU's that we haven't seen yet (and that might
 210          *    still change the stack area.
 211          * and
 212          *  - all other users take the lock (ie we can only
 213          *    have _one_ other CPU that looks at or modifies
 214          *    the list).
 215          */
 216         if (!list_empty_careful(&wait->task_list)) {
 217                 spin_lock_irqsave(&q->lock, flags);
 218                 list_del_init(&wait->task_list);
 219                 spin_unlock_irqrestore(&q->lock, flags);
 220         }
 221 }
 222
 223 EXPORT_SYMBOL(finish_wait);
 224
 225 int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key)
 226 {
 227         int ret = default_wake_function(wait, mode, sync, key);
 228
 229         if (ret)
 230                 list_del_init(&wait->task_list);
 231         return ret;
 232 }
 233
 234 EXPORT_SYMBOL(autoremove_wake_function);
 235
 236 void __init fork_init(unsigned long mempages)
 237 {
 238 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
 239 #ifndef ARCH_MIN_TASKALIGN
 240 #define ARCH_MIN_TASKALIGN      L1_CACHE_BYTES
 241 #endif
 242         /* create a slab on which task_structs can be allocated */
 243         task_struct_cachep =
 244                 kmem_cache_create("task_struct", sizeof(struct task_struct),
 245                         ARCH_MIN_TASKALIGN, SLAB_PANIC, NULL, NULL);
 246 #endif
 247
 248         /*
 249          * The default maximum number of threads is set to a safe
 250          * value: the thread structures can take up at most half
 251          * of memory.
 252          */
 253         max_threads = mempages / (THREAD_SIZE/PAGE_SIZE) / 8;
 254         /*
 255          * we need to allow at least 20 threads to boot a system
 256          */
 257         if(max_threads < 20)
 258                 max_threads = 20;
 259
 260         init_task.rlim[RLIMIT_NPROC].rlim_cur = max_threads/2;
 261         init_task.rlim[RLIMIT_NPROC].rlim_max = max_threads/2;
 262 }
 263
 264 static struct task_struct *dup_task_struct(struct task_struct *orig)
 265 {
 266         struct task_struct *tsk;
 267         struct thread_info *ti;
 268
 269         prepare_to_copy(orig);
 270
 271         tsk = alloc_task_struct();
 272         if (!tsk)
 273                 return NULL;
 274
 275         ti = alloc_thread_info(tsk);
 276         if (!ti) {
 277                 free_task_struct(tsk);
 278                 return NULL;
 279         }
 280
 281         *ti = *orig->thread_info;
 282         *tsk = *orig;
 283         tsk->thread_info = ti;
 284         ti->task = tsk;
 285
 286         ckrm_cb_newtask(tsk);
 287         /* One for us, one for whoever does the "release_task()" (usually parent) */
 288         atomic_set(&tsk->usage,2);
 289 #ifdef CONFIG_CKRM_RES_MEM
 290         INIT_LIST_HEAD(&tsk->mm_peers);
 291 #endif
 292         return tsk;
 293 }
 294
 295 #ifdef CONFIG_MMU
 296 static inline int dup_mmap(struct mm_struct * mm, struct mm_struct * oldmm)
 297 {
 298         struct vm_area_struct * mpnt, *tmp, **pprev;
 299         struct rb_node **rb_link, *rb_parent;
 300         int retval;
 301         unsigned long charge;
 302         struct mempolicy *pol;
 303
 304         down_write(&oldmm->mmap_sem);
 305         flush_cache_mm(current->mm);
 306         mm->locked_vm = 0;
 307         mm->mmap = NULL;
 308         mm->mmap_cache = NULL;
 309         mm->free_area_cache = oldmm->mmap_base;
 310         mm->map_count = 0;
 311         mm->rss = 0;
 312         mm->anon_rss = 0;
 313         cpus_clear(mm->cpu_vm_mask);
 314         mm->mm_rb = RB_ROOT;
 315         rb_link = &mm->mm_rb.rb_node;
 316         rb_parent = NULL;
 317         pprev = &mm->mmap;
 318
 319         /*
 320          * Add it to the mmlist after the parent.
 321          * Doing it this way means that we can order the list,
 322          * and fork() won't mess up the ordering significantly.
 323          * Add it first so that swapoff can see any swap entries.
 324          */
 325         spin_lock(&mmlist_lock);
 326         list_add(&mm->mmlist, &current->mm->mmlist);
 327         mmlist_nr++;
 328         spin_unlock(&mmlist_lock);
 329
 330         for (mpnt = current->mm->mmap ; mpnt ; mpnt = mpnt->vm_next) {
 331                 struct file *file;
 332
 333                 if (mpnt->vm_flags & VM_DONTCOPY) {
 334                         __vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file,
 335                                                         -vma_pages(mpnt));
 336                         continue;
 337                 }
 338                 charge = 0;
 339                 if (mpnt->vm_flags & VM_ACCOUNT) {
 340                         unsigned int len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
 341                         if (security_vm_enough_memory(len))
 342                                 goto fail_nomem;
 343                         charge = len;
 344                 }
 345                 tmp = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 346                 if (!tmp)
 347                         goto fail_nomem;
 348                 *tmp = *mpnt;
 349                 pol = mpol_copy(vma_policy(mpnt));
 350                 retval = PTR_ERR(pol);
 351                 if (IS_ERR(pol))
 352                         goto fail_nomem_policy;
 353                 vma_set_policy(tmp, pol);
 354                 tmp->vm_flags &= ~VM_LOCKED;
 355                 tmp->vm_mm = mm;
 356                 tmp->vm_next = NULL;
 357                 anon_vma_link(tmp);
 358                 file = tmp->vm_file;
 359                 if (file) {
 360                         struct inode *inode = file->f_dentry->d_inode;
 361                         get_file(file);
 362                         if (tmp->vm_flags & VM_DENYWRITE)
 363                                 atomic_dec(&inode->i_writecount);
 364
 365                         /* insert tmp into the share list, just after mpnt */
 366                         spin_lock(&file->f_mapping->i_mmap_lock);
 367                         flush_dcache_mmap_lock(file->f_mapping);
 368                         vma_prio_tree_add(tmp, mpnt);
 369                         flush_dcache_mmap_unlock(file->f_mapping);
 370                         spin_unlock(&file->f_mapping->i_mmap_lock);
 371                 }
 372
 373                 /*
 374                  * Link in the new vma and copy the page table entries:
 375                  * link in first so that swapoff can see swap entries,
 376                  * and try_to_unmap_one's find_vma find the new vma.
 377                  */
 378                 spin_lock(&mm->page_table_lock);
 379                 *pprev = tmp;
 380                 pprev = &tmp->vm_next;
 381
 382                 __vma_link_rb(mm, tmp, rb_link, rb_parent);
 383                 rb_link = &tmp->vm_rb.rb_right;
 384                 rb_parent = &tmp->vm_rb;
 385
 386                 mm->map_count++;
 387                 retval = copy_page_range(mm, current->mm, tmp);
 388                 spin_unlock(&mm->page_table_lock);
 389
 390                 if (tmp->vm_ops && tmp->vm_ops->open)
 391                         tmp->vm_ops->open(tmp);
 392
 393                 if (retval)
 394                         goto out;
 395         }
 396         retval = 0;
 397
 398 out:
 399         flush_tlb_mm(current->mm);
 400         up_write(&oldmm->mmap_sem);
 401         return retval;
 402 fail_nomem_policy:
 403         kmem_cache_free(vm_area_cachep, tmp);
 404 fail_nomem:
 405         retval = -ENOMEM;
 406         vm_unacct_memory(charge);
 407         goto out;
 408 }
 409
 410 static inline int mm_alloc_pgd(struct mm_struct * mm)
 411 {
 412         mm->pgd = pgd_alloc(mm);
 413         if (unlikely(!mm->pgd))
 414                 return -ENOMEM;
 415         return 0;
 416 }
 417
 418 static inline void mm_free_pgd(struct mm_struct * mm)
 419 {
 420         pgd_free(mm->pgd);
 421 }
 422 #else
 423 #define dup_mmap(mm, oldmm)     (0)
 424 #define mm_alloc_pgd(mm)        (0)
 425 #define mm_free_pgd(mm)
 426 #endif /* CONFIG_MMU */
 427
 428 spinlock_t mmlist_lock __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
 429 int mmlist_nr;
 430
 431 #define allocate_mm()   (kmem_cache_alloc(mm_cachep, SLAB_KERNEL))
 432 #define free_mm(mm)     (kmem_cache_free(mm_cachep, (mm)))
 433
 434 #include <linux/init_task.h>
 435
 436 static struct mm_struct * mm_init(struct mm_struct * mm)
 437 {
 438         atomic_set(&mm->mm_users, 1);
 439         atomic_set(&mm->mm_count, 1);
 440         init_rwsem(&mm->mmap_sem);
 441         mm->core_waiters = 0;
 442         mm->page_table_lock = SPIN_LOCK_UNLOCKED;
 443         mm->ioctx_list_lock = RW_LOCK_UNLOCKED;
 444         mm->ioctx_list = NULL;
 445         mm->default_kioctx = (struct kioctx)INIT_KIOCTX(mm->default_kioctx, *mm);
 446         mm->free_area_cache = TASK_UNMAPPED_BASE;
 447 #ifdef CONFIG_CKRM_RES_MEM
 448         INIT_LIST_HEAD(&mm->tasklist);
 449         mm->peertask_lock = SPIN_LOCK_UNLOCKED;
 450 #endif
 451
 452         if (likely(!mm_alloc_pgd(mm))) {
 453                 mm->def_flags = 0;
 454                 set_vx_info(&mm->mm_vx_info, current->vx_info);
 455                 return mm;
 456         }
 457         free_mm(mm);
 458         return NULL;
 459 }
 460
 461 /*
 462  * Allocate and initialize an mm_struct.
 463  */
 464 struct mm_struct * mm_alloc(void)
 465 {
 466         struct mm_struct * mm;
 467
 468         mm = allocate_mm();
 469         if (mm) {
 470                 memset(mm, 0, sizeof(*mm));
 471                 mm = mm_init(mm);
 472 #ifdef CONFIG_CKRM_RES_MEM
 473                 mm->memclass = GET_MEM_CLASS(current);
 474                 mem_class_get(mm->memclass);
 475 #endif
 476         }
 477         return mm;
 478 }
 479
 480 /*
 481  * Called when the last reference to the mm
 482  * is dropped: either by a lazy thread or by
 483  * mmput. Free the page directory and the mm.
 484  */
 485 void fastcall __mmdrop(struct mm_struct *mm)
 486 {
 487         BUG_ON(mm == &init_mm);
 488         mm_free_pgd(mm);
 489         destroy_context(mm);
 490         clr_vx_info(&mm->mm_vx_info);
 491 #ifdef CONFIG_CKRM_RES_MEM
 492         /* class can be null and mm's tasklist can be empty here */
 493         if (mm->memclass) {
 494                 mem_class_put(mm->memclass);
 495                 mm->memclass = NULL;
 496         }
 497 #endif
 498         free_mm(mm);
 499 }
 500
 501 /*
 502  * Decrement the use count and release all resources for an mm.
 503  */
 504 void mmput(struct mm_struct *mm)
 505 {
 506         if (atomic_dec_and_lock(&mm->mm_users, &mmlist_lock)) {
 507                 list_del(&mm->mmlist);
 508                 mmlist_nr--;
 509                 spin_unlock(&mmlist_lock);
 510                 exit_aio(mm);
 511                 exit_mmap(mm);
 512                 put_swap_token(mm);
 513                 mmdrop(mm);
 514         }
 515 }
 516 EXPORT_SYMBOL_GPL(mmput);
 517
 518 /**
 519  * get_task_mm - acquire a reference to the task's mm
 520  *
 521  * Returns %NULL if the task has no mm.  Checks if the use count
 522  * of the mm is non-zero and if so returns a reference to it, after
 523  * bumping up the use count.  User must release the mm via mmput()
 524  * after use.  Typically used by /proc and ptrace.
 525  *
 526  * If the use count is zero, it means that this mm is going away,
 527  * so return %NULL.  This only happens in the case of an AIO daemon
 528  * which has temporarily adopted an mm (see use_mm), in the course
 529  * of its final mmput, before exit_aio has completed.
 530  */
 531 struct mm_struct *get_task_mm(struct task_struct *task)
 532 {
 533         struct mm_struct *mm;
 534
 535         task_lock(task);
 536         mm = task->mm;
 537         if (mm) {
 538                 spin_lock(&mmlist_lock);
 539                 if (!atomic_read(&mm->mm_users))
 540                         mm = NULL;
 541                 else
 542                         atomic_inc(&mm->mm_users);
 543                 spin_unlock(&mmlist_lock);
 544         }
 545         task_unlock(task);
 546         return mm;
 547 }
 548 EXPORT_SYMBOL_GPL(get_task_mm);
 549
 550 /* Please note the differences between mmput and mm_release.
 551  * mmput is called whenever we stop holding onto a mm_struct,
 552  * error success whatever.
 553  *
 554  * mm_release is called after a mm_struct has been removed
 555  * from the current process.
 556  *
 557  * This difference is important for error handling, when we
 558  * only half set up a mm_struct for a new process and need to restore
 559  * the old one.  Because we mmput the new mm_struct before
 560  * restoring the old one. . .
 561  * Eric Biederman 10 January 1998
 562  */
 563 void mm_release(struct task_struct *tsk, struct mm_struct *mm)
 564 {
 565         struct completion *vfork_done = tsk->vfork_done;
 566
 567         /* Get rid of any cached register state */
 568         deactivate_mm(tsk, mm);
 569
 570         /* notify parent sleeping on vfork() */
 571         if (vfork_done) {
 572                 tsk->vfork_done = NULL;
 573                 complete(vfork_done);
 574         }
 575         if (tsk->clear_child_tid && atomic_read(&mm->mm_users) > 1) {
 576                 u32 __user * tidptr = tsk->clear_child_tid;
 577                 tsk->clear_child_tid = NULL;
 578
 579                 /*
 580                  * We don't check the error code - if userspace has
 581                  * not set up a proper pointer then tough luck.
 582                  */
 583                 put_user(0, tidptr);
 584                 sys_futex(tidptr, FUTEX_WAKE, 1, NULL, NULL, 0);
 585         }
 586 }
 587
 588 static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
 589 {
 590         struct mm_struct * mm, *oldmm;
 591         int retval;
 592
 593         tsk->min_flt = tsk->maj_flt = 0;
 594         tsk->nvcsw = tsk->nivcsw = 0;
 595
 596         tsk->mm = NULL;
 597         tsk->active_mm = NULL;
 598
 599         /*
 600          * Are we cloning a kernel thread?
 601          *
 602          * We need to steal a active VM for that..
 603          */
 604         oldmm = current->mm;
 605         if (!oldmm)
 606                 return 0;
 607
 608         if (clone_flags & CLONE_VM) {
 609                 atomic_inc(&oldmm->mm_users);
 610                 mm = oldmm;
 611                 /*
 612                  * There are cases where the PTL is held to ensure no
 613                  * new threads start up in user mode using an mm, which
 614                  * allows optimizing out ipis; the tlb_gather_mmu code
 615                  * is an example.
 616                  */
 617                 spin_unlock_wait(&oldmm->page_table_lock);
 618                 goto good_mm;
 619         }
 620
 621         retval = -ENOMEM;
 622         mm = allocate_mm();
 623         if (!mm)
 624                 goto fail_nomem;
 625
 626         /* Copy the current MM stuff.. */
 627         memcpy(mm, oldmm, sizeof(*mm));
 628         mm->mm_vx_info = NULL;
 629         if (!mm_init(mm))
 630                 goto fail_nomem;
 631
 632         if (init_new_context(tsk,mm))
 633                 goto fail_nocontext;
 634
 635         retval = dup_mmap(mm, oldmm);
 636         if (retval)
 637                 goto free_pt;
 638
 639 good_mm:
 640         tsk->mm = mm;
 641         tsk->active_mm = mm;
 642         ckrm_init_mm_to_task(mm, tsk);
 643         return 0;
 644
 645 free_pt:
 646         mmput(mm);
 647 fail_nomem:
 648         return retval;
 649
 650 fail_nocontext:
 651         /*
 652          * If init_new_context() failed, we cannot use mmput() to free the mm
 653          * because it calls destroy_context()
 654          */
 655         mm_free_pgd(mm);
 656         free_mm(mm);
 657         return retval;
 658 }
 659
 660 static inline struct fs_struct *__copy_fs_struct(struct fs_struct *old)
 661 {
 662         struct fs_struct *fs = kmem_cache_alloc(fs_cachep, GFP_KERNEL);
 663         /* We don't need to lock fs - think why ;-) */
 664         if (fs) {
 665                 atomic_set(&fs->count, 1);
 666                 fs->lock = RW_LOCK_UNLOCKED;
 667                 fs->umask = old->umask;
 668                 read_lock(&old->lock);
 669                 fs->rootmnt = mntget(old->rootmnt);
 670                 fs->root = dget(old->root);
 671                 fs->pwdmnt = mntget(old->pwdmnt);
 672                 fs->pwd = dget(old->pwd);
 673                 if (old->altroot) {
 674                         fs->altrootmnt = mntget(old->altrootmnt);
 675                         fs->altroot = dget(old->altroot);
 676                 } else {
 677                         fs->altrootmnt = NULL;
 678                         fs->altroot = NULL;
 679                 }
 680                 read_unlock(&old->lock);
 681         }
 682         return fs;
 683 }
 684
 685 struct fs_struct *copy_fs_struct(struct fs_struct *old)
 686 {
 687         return __copy_fs_struct(old);
 688 }
 689
 690 EXPORT_SYMBOL_GPL(copy_fs_struct);
 691
 692 static inline int copy_fs(unsigned long clone_flags, struct task_struct * tsk)
 693 {
 694         if (clone_flags & CLONE_FS) {
 695                 atomic_inc(&current->fs->count);
 696                 return 0;
 697         }
 698         tsk->fs = __copy_fs_struct(current->fs);
 699         if (!tsk->fs)
 700                 return -ENOMEM;
 701         return 0;
 702 }
 703
 704 static int count_open_files(struct files_struct *files, int size)
 705 {
 706         int i;
 707
 708         /* Find the last open fd */
 709         for (i = size/(8*sizeof(long)); i > 0; ) {
 710                 if (files->open_fds->fds_bits[--i])
 711                         break;
 712         }
 713         i = (i+1) * 8 * sizeof(long);
 714         return i;
 715 }
 716
 717 static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
 718 {
 719         struct files_struct *oldf, *newf;
 720         struct file **old_fds, **new_fds;
 721         int open_files, nfds, size, i, error = 0;
 722
 723         /*
 724          * A background process may not have any files ...
 725          */
 726         oldf = current->files;
 727         if (!oldf)
 728                 goto out;
 729
 730         if (clone_flags & CLONE_FILES) {
 731                 atomic_inc(&oldf->count);
 732                 goto out;
 733         }
 734
 735         /*
 736          * Note: we may be using current for both targets (See exec.c)
 737          * This works because we cache current->files (old) as oldf. Don't
 738          * break this.
 739          */
 740         tsk->files = NULL;
 741         error = -ENOMEM;
 742         newf = kmem_cache_alloc(files_cachep, SLAB_KERNEL);
 743         if (!newf)
 744                 goto out;
 745
 746         atomic_set(&newf->count, 1);
 747
 748         newf->file_lock     = SPIN_LOCK_UNLOCKED;
 749         newf->next_fd       = 0;
 750         newf->max_fds       = NR_OPEN_DEFAULT;
 751         newf->max_fdset     = __FD_SETSIZE;
 752         newf->close_on_exec = &newf->close_on_exec_init;
 753         newf->open_fds      = &newf->open_fds_init;
 754         newf->fd            = &newf->fd_array[0];
 755
 756         /* We don't yet have the oldf readlock, but even if the old
 757            fdset gets grown now, we'll only copy up to "size" fds */
 758         size = oldf->max_fdset;
 759         if (size > __FD_SETSIZE) {
 760                 newf->max_fdset = 0;
 761                 spin_lock(&newf->file_lock);
 762                 error = expand_fdset(newf, size-1);
 763                 spin_unlock(&newf->file_lock);
 764                 if (error)
 765                         goto out_release;
 766         }
 767         spin_lock(&oldf->file_lock);
 768
 769         open_files = count_open_files(oldf, size);
 770
 771         /*
 772          * Check whether we need to allocate a larger fd array.
 773          * Note: we're not a clone task, so the open count won't
 774          * change.
 775          */
 776         nfds = NR_OPEN_DEFAULT;
 777         if (open_files > nfds) {
 778                 spin_unlock(&oldf->file_lock);
 779                 newf->max_fds = 0;
 780                 spin_lock(&newf->file_lock);
 781                 error = expand_fd_array(newf, open_files-1);
 782                 spin_unlock(&newf->file_lock);
 783                 if (error)
 784                         goto out_release;
 785                 nfds = newf->max_fds;
 786                 spin_lock(&oldf->file_lock);
 787         }
 788
 789         old_fds = oldf->fd;
 790         new_fds = newf->fd;
 791
 792         memcpy(newf->open_fds->fds_bits, oldf->open_fds->fds_bits, open_files/8);
 793         memcpy(newf->close_on_exec->fds_bits, oldf->close_on_exec->fds_bits, open_files/8);
 794
 795         for (i = open_files; i != 0; i--) {
 796                 struct file *f = *old_fds++;
 797                 if (f)
 798                         get_file(f);
 799                 *new_fds++ = f;
 800         }
 801         spin_unlock(&oldf->file_lock);
 802
 803         /* compute the remainder to be cleared */
 804         size = (newf->max_fds - open_files) * sizeof(struct file *);
 805
 806         /* This is long word aligned thus could use a optimized version */
 807         memset(new_fds, 0, size);
 808
 809         if (newf->max_fdset > open_files) {
 810                 int left = (newf->max_fdset-open_files)/8;
 811                 int start = open_files / (8 * sizeof(unsigned long));
 812
 813                 memset(&newf->open_fds->fds_bits[start], 0, left);
 814                 memset(&newf->close_on_exec->fds_bits[start], 0, left);
 815         }
 816
 817         tsk->files = newf;
 818         error = 0;
 819 out:
 820         return error;
 821
 822 out_release:
 823         free_fdset (newf->close_on_exec, newf->max_fdset);
 824         free_fdset (newf->open_fds, newf->max_fdset);
 825         kmem_cache_free(files_cachep, newf);
 826         goto out;
 827 }
 828
 829 /*
 830  *      Helper to unshare the files of the current task.
 831  *      We don't want to expose copy_files internals to
 832  *      the exec layer of the kernel.
 833  */
 834
 835 int unshare_files(void)
 836 {
 837         struct files_struct *files  = current->files;
 838         int rc;
 839
 840         if(!files)
 841                 BUG();
 842
 843         /* This can race but the race causes us to copy when we don't
 844            need to and drop the copy */
 845         if(atomic_read(&files->count) == 1)
 846         {
 847                 atomic_inc(&files->count);
 848                 return 0;
 849         }
 850         rc = copy_files(0, current);
 851         if(rc)
 852                 current->files = files;
 853         return rc;
 854 }
 855
 856 EXPORT_SYMBOL(unshare_files);
 857
 858 static inline int copy_sighand(unsigned long clone_flags, struct task_struct * tsk)
 859 {
 860         struct sighand_struct *sig;
 861
 862         if (clone_flags & (CLONE_SIGHAND | CLONE_THREAD)) {
 863                 atomic_inc(&current->sighand->count);
 864                 return 0;
 865         }
 866         sig = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
 867         tsk->sighand = sig;
 868         if (!sig)
 869                 return -ENOMEM;
 870         spin_lock_init(&sig->siglock);
 871         atomic_set(&sig->count, 1);
 872         memcpy(sig->action, current->sighand->action, sizeof(sig->action));
 873         return 0;
 874 }
 875
 876 static inline int copy_signal(unsigned long clone_flags, struct task_struct * tsk)
 877 {
 878         struct signal_struct *sig;
 879
 880         if (clone_flags & CLONE_THREAD) {
 881                 atomic_inc(&current->signal->count);
 882                 return 0;
 883         }
 884         sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
 885         tsk->signal = sig;
 886         if (!sig)
 887                 return -ENOMEM;
 888         atomic_set(&sig->count, 1);
 889         sig->group_exit = 0;
 890         sig->group_exit_code = 0;
 891         sig->group_exit_task = NULL;
 892         sig->group_stop_count = 0;
 893         sig->curr_target = NULL;
 894         init_sigpending(&sig->shared_pending);
 895         INIT_LIST_HEAD(&sig->posix_timers);
 896
 897         sig->tty = current->signal->tty;
 898         sig->pgrp = process_group(current);
 899         sig->session = current->signal->session;
 900         sig->leader = 0;        /* session leadership doesn't inherit */
 901         sig->tty_old_pgrp = 0;
 902
 903         sig->utime = sig->stime = sig->cutime = sig->cstime = 0;
 904         sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
 905         sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
 906
 907         return 0;
 908 }
 909
 910 static inline void copy_flags(unsigned long clone_flags, struct task_struct *p)
 911 {
 912         unsigned long new_flags = p->flags;
 913
 914         new_flags &= ~PF_SUPERPRIV;
 915         new_flags |= PF_FORKNOEXEC;
 916         if (!(clone_flags & CLONE_PTRACE))
 917                 p->ptrace = 0;
 918         p->flags = new_flags;
 919 }
 920
 921 asmlinkage long sys_set_tid_address(int __user *tidptr)
 922 {
 923         current->clear_child_tid = tidptr;
 924
 925         return current->pid;
 926 }
 927
 928 /*
 929  * This creates a new process as a copy of the old one,
 930  * but does not actually start it yet.
 931  *
 932  * It copies the registers, and all the appropriate
 933  * parts of the process environment (as per the clone
 934  * flags). The actual kick-off is left to the caller.
 935  */
 936 static task_t *copy_process(unsigned long clone_flags,
 937                                  unsigned long stack_start,
 938                                  struct pt_regs *regs,
 939                                  unsigned long stack_size,
 940                                  int __user *parent_tidptr,
 941                                  int __user *child_tidptr,
 942                                  int pid)
 943 {
 944         int retval;
 945         struct task_struct *p = NULL;
 946         struct vx_info *vxi;
 947
 948         if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
 949                 return ERR_PTR(-EINVAL);
 950
 951         /*
 952          * Thread groups must share signals as well, and detached threads
 953          * can only be started up within the thread group.
 954          */
 955         if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
 956                 return ERR_PTR(-EINVAL);
 957
 958         /*
 959          * Shared signal handlers imply shared VM. By way of the above,
 960          * thread groups also imply shared VM. Blocking this case allows
 961          * for various simplifications in other code.
 962          */
 963         if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
 964                 return ERR_PTR(-EINVAL);
 965
 966         retval = security_task_create(clone_flags);
 967         if (retval)
 968                 goto fork_out;
 969
 970         retval = -ENOMEM;
 971         p = dup_task_struct(current);
 972         if (!p)
 973                 goto fork_out;
 974         p->tux_info = NULL;
 975
 976         p->vx_info = NULL;
 977         set_vx_info(&p->vx_info, current->vx_info);
 978         p->nx_info = NULL;
 979         set_nx_info(&p->nx_info, current->nx_info);
 980
 981         /* check vserver memory */
 982         if (p->mm && !(clone_flags & CLONE_VM)) {
 983                 if (vx_vmpages_avail(p->mm, p->mm->total_vm))
 984                         vx_pages_add(p->mm->mm_vx_info, RLIMIT_AS, p->mm->total_vm);
 985                 else
 986                         goto bad_fork_free;
 987         }
 988         if (p->mm && vx_flags(VXF_FORK_RSS, 0)) {
 989                 if (!vx_rsspages_avail(p->mm, p->mm->rss))
 990                         goto bad_fork_cleanup_vm;
 991         }
 992
 993         retval = -EAGAIN;
 994         if (!vx_nproc_avail(1))
 995                 goto bad_fork_cleanup_vm;
 996
 997         if (atomic_read(&p->user->processes) >=
 998                         p->rlim[RLIMIT_NPROC].rlim_cur) {
 999                 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
1000                                 p->user != &root_user)
1001                         goto bad_fork_cleanup_vm;
1002         }
1003
1004         atomic_inc(&p->user->__count);
1005         atomic_inc(&p->user->processes);
1006         get_group_info(p->group_info);
1007
1008         /*
1009          * If multiple threads are within copy_process(), then this check
1010          * triggers too late. This doesn't hurt, the check is only there
1011          * to stop root fork bombs.
1012          */
1013         if (nr_threads >= max_threads)
1014                 goto bad_fork_cleanup_count;
1015
1016         if (!try_module_get(p->thread_info->exec_domain->module))
1017                 goto bad_fork_cleanup_count;
1018
1019         if (p->binfmt && !try_module_get(p->binfmt->module))
1020                 goto bad_fork_cleanup_put_domain;
1021
1022         init_delays(p);
1023         p->did_exec = 0;
1024         copy_flags(clone_flags, p);
1025         p->pid = pid;
1026         retval = -EFAULT;
1027         if (clone_flags & CLONE_PARENT_SETTID)
1028                 if (put_user(p->pid, parent_tidptr))
1029                         goto bad_fork_cleanup;
1030
1031         p->proc_dentry = NULL;
1032
1033         INIT_LIST_HEAD(&p->children);
1034         INIT_LIST_HEAD(&p->sibling);
1035         init_waitqueue_head(&p->wait_chldexit);
1036         p->vfork_done = NULL;
1037         spin_lock_init(&p->alloc_lock);
1038         spin_lock_init(&p->proc_lock);
1039
1040         clear_tsk_thread_flag(p, TIF_SIGPENDING);
1041         init_sigpending(&p->pending);
1042
1043         p->it_real_value = p->it_virt_value = p->it_prof_value = 0;
1044         p->it_real_incr = p->it_virt_incr = p->it_prof_incr = 0;
1045         init_timer(&p->real_timer);
1046         p->real_timer.data = (unsigned long) p;
1047
1048         p->utime = p->stime = 0;
1049         p->lock_depth = -1;             /* -1 = no lock */
1050         do_posix_clock_monotonic_gettime(&p->start_time);
1051         p->security = NULL;
1052         p->io_context = NULL;
1053         p->io_wait = NULL;
1054         p->audit_context = NULL;
1055 #ifdef CONFIG_NUMA
1056         p->mempolicy = mpol_copy(p->mempolicy);
1057         if (IS_ERR(p->mempolicy)) {
1058                 retval = PTR_ERR(p->mempolicy);
1059                 p->mempolicy = NULL;
1060                 goto bad_fork_cleanup;
1061         }
1062 #endif
1063
1064         if ((retval = security_task_alloc(p)))
1065                 goto bad_fork_cleanup_policy;
1066         if ((retval = audit_alloc(p)))
1067                 goto bad_fork_cleanup_security;
1068         /* copy all the process information */
1069         if ((retval = copy_semundo(clone_flags, p)))
1070                 goto bad_fork_cleanup_audit;
1071         if ((retval = copy_files(clone_flags, p)))
1072                 goto bad_fork_cleanup_semundo;
1073         if ((retval = copy_fs(clone_flags, p)))
1074                 goto bad_fork_cleanup_files;
1075         if ((retval = copy_sighand(clone_flags, p)))
1076                 goto bad_fork_cleanup_fs;
1077         if ((retval = copy_signal(clone_flags, p)))
1078                 goto bad_fork_cleanup_sighand;
1079         if ((retval = copy_mm(clone_flags, p)))
1080                 goto bad_fork_cleanup_signal;
1081         if ((retval = copy_namespace(clone_flags, p)))
1082                 goto bad_fork_cleanup_mm;
1083         retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
1084         if (retval)
1085                 goto bad_fork_cleanup_namespace;
1086
1087         p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
1088         /*
1089          * Clear TID on mm_release()?
1090          */
1091         p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
1092
1093         /*
1094          * Syscall tracing should be turned off in the child regardless
1095          * of CLONE_PTRACE.
1096          */
1097         clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
1098
1099         /* Our parent execution domain becomes current domain
1100            These must match for thread signalling to apply */
1101
1102         p->parent_exec_id = p->self_exec_id;
1103
1104         /* ok, now we should be set up.. */
1105         p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
1106         p->pdeath_signal = 0;
1107         p->exit_state = 0;
1108
1109         /* Perform scheduler related setup */
1110         sched_fork(p);
1111
1112         /*
1113          * Ok, make it visible to the rest of the system.
1114          * We dont wake it up yet.
1115          */
1116         p->tgid = p->pid;
1117         p->group_leader = p;
1118         INIT_LIST_HEAD(&p->ptrace_children);
1119         INIT_LIST_HEAD(&p->ptrace_list);
1120
1121         /* Need tasklist lock for parent etc handling! */
1122         write_lock_irq(&tasklist_lock);
1123
1124         /*
1125          * The task hasn't been attached yet, so cpus_allowed mask cannot
1126          * have changed. The cpus_allowed mask of the parent may have
1127          * changed after it was copied first time, and it may then move to
1128          * another CPU - so we re-copy it here and set the child's CPU to
1129          * the parent's CPU. This avoids alot of nasty races.
1130          */
1131         p->cpus_allowed = current->cpus_allowed;
1132         set_task_cpu(p, smp_processor_id());
1133
1134         /*
1135          * Check for pending SIGKILL! The new thread should not be allowed
1136          * to slip out of an OOM kill. (or normal SIGKILL.)
1137          */
1138         if (sigismember(&current->pending.signal, SIGKILL)) {
1139                 write_unlock_irq(&tasklist_lock);
1140                 retval = -EINTR;
1141                 goto bad_fork_cleanup_namespace;
1142         }
1143
1144         /* CLONE_PARENT re-uses the old parent */
1145         if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
1146                 p->real_parent = current->real_parent;
1147         else
1148                 p->real_parent = current;
1149         p->parent = p->real_parent;
1150
1151         if (clone_flags & CLONE_THREAD) {
1152                 spin_lock(&current->sighand->siglock);
1153                 /*
1154                  * Important: if an exit-all has been started then
1155                  * do not create this new thread - the whole thread
1156                  * group is supposed to exit anyway.
1157                  */
1158                 if (current->signal->group_exit) {
1159                         spin_unlock(&current->sighand->siglock);
1160                         write_unlock_irq(&tasklist_lock);
1161                         retval = -EAGAIN;
1162                         goto bad_fork_cleanup_namespace;
1163                 }
1164                 p->tgid = current->tgid;
1165                 p->group_leader = current->group_leader;
1166
1167                 if (current->signal->group_stop_count > 0) {
1168                         /*
1169                          * There is an all-stop in progress for the group.
1170                          * We ourselves will stop as soon as we check signals.
1171                          * Make the new thread part of that group stop too.
1172                          */
1173                         current->signal->group_stop_count++;
1174                         set_tsk_thread_flag(p, TIF_SIGPENDING);
1175                 }
1176
1177                 spin_unlock(&current->sighand->siglock);
1178         }
1179
1180         SET_LINKS(p);
1181         if (unlikely(p->ptrace & PT_PTRACED))
1182                 __ptrace_link(p, current->parent);
1183
1184         attach_pid(p, PIDTYPE_PID, p->pid);
1185         attach_pid(p, PIDTYPE_TGID, p->tgid);
1186         if (thread_group_leader(p)) {
1187                 attach_pid(p, PIDTYPE_PGID, process_group(p));
1188                 attach_pid(p, PIDTYPE_SID, p->signal->session);
1189                 if (p->pid)
1190                         __get_cpu_var(process_counts)++;
1191         }
1192
1193         p->ioprio = current->ioprio;
1194         nr_threads++;
1195         /* p is copy of current */
1196         vxi = p->vx_info;
1197         if (vxi) {
1198                 atomic_inc(&vxi->cvirt.nr_threads);
1199                 vx_nproc_inc(p);
1200         }
1201         write_unlock_irq(&tasklist_lock);
1202         retval = 0;
1203
1204 fork_out:
1205         if (retval)
1206                 return ERR_PTR(retval);
1207         return p;
1208
1209 bad_fork_cleanup_namespace:
1210         exit_namespace(p);
1211 bad_fork_cleanup_mm:
1212         if (p->mm)
1213                 mmput(p->mm);
1214 bad_fork_cleanup_signal:
1215         exit_signal(p);
1216 bad_fork_cleanup_sighand:
1217         exit_sighand(p);
1218 bad_fork_cleanup_fs:
1219         exit_fs(p); /* blocking */
1220 bad_fork_cleanup_files:
1221         exit_files(p); /* blocking */
1222 bad_fork_cleanup_semundo:
1223         exit_sem(p);
1224 bad_fork_cleanup_audit:
1225         audit_free(p);
1226 bad_fork_cleanup_security:
1227         security_task_free(p);
1228 bad_fork_cleanup_policy:
1229 #ifdef CONFIG_NUMA
1230         mpol_free(p->mempolicy);
1231 #endif
1232 bad_fork_cleanup:
1233         if (p->binfmt)
1234                 module_put(p->binfmt->module);
1235 bad_fork_cleanup_put_domain:
1236         module_put(p->thread_info->exec_domain->module);
1237 bad_fork_cleanup_count:
1238         put_group_info(p->group_info);
1239         atomic_dec(&p->user->processes);
1240         free_uid(p->user);
1241 bad_fork_cleanup_vm:
1242         if (p->mm && !(clone_flags & CLONE_VM))
1243                 vx_pages_sub(p->mm->mm_vx_info, RLIMIT_AS, p->mm->total_vm);
1244 bad_fork_free:
1245         free_task(p);
1246         goto fork_out;
1247 }
1248
1249 struct pt_regs * __devinit __attribute__((weak)) idle_regs(struct pt_regs *regs)
1250 {
1251         memset(regs, 0, sizeof(struct pt_regs));
1252         return regs;
1253 }
1254
1255 task_t * __devinit fork_idle(int cpu)
1256 {
1257         task_t *task;
1258         struct pt_regs regs;
1259
1260         task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL, NULL, 0);
1261         if (!task)
1262                 return ERR_PTR(-ENOMEM);
1263         init_idle(task, cpu);
1264         unhash_process(task);
1265         return task;
1266 }
1267
1268 static inline int fork_traceflag (unsigned clone_flags)
1269 {
1270         if (clone_flags & CLONE_UNTRACED)
1271                 return 0;
1272         else if (clone_flags & CLONE_VFORK) {
1273                 if (current->ptrace & PT_TRACE_VFORK)
1274                         return PTRACE_EVENT_VFORK;
1275         } else if ((clone_flags & CSIGNAL) != SIGCHLD) {
1276                 if (current->ptrace & PT_TRACE_CLONE)
1277                         return PTRACE_EVENT_CLONE;
1278         } else if (current->ptrace & PT_TRACE_FORK)
1279                 return PTRACE_EVENT_FORK;
1280
1281         return 0;
1282 }
1283
1284 /*
1285  *  Ok, this is the main fork-routine.
1286  *
1287  * It copies the process, and if successful kick-starts
1288  * it and waits for it to finish using the VM if required.
1289  */
1290 long do_fork(unsigned long clone_flags,
1291               unsigned long stack_start,
1292               struct pt_regs *regs,
1293               unsigned long stack_size,
1294               int __user *parent_tidptr,
1295               int __user *child_tidptr)
1296 {
1297         struct task_struct *p;
1298         int trace = 0;
1299         long pid = alloc_pidmap();
1300
1301         if (pid < 0)
1302                 return -EAGAIN;
1303         if (unlikely(current->ptrace)) {
1304                 trace = fork_traceflag (clone_flags);
1305                 if (trace)
1306                         clone_flags |= CLONE_PTRACE;
1307         }
1308
1309 #ifdef CONFIG_CKRM_TYPE_TASKCLASS
1310         if (numtasks_get_ref(current->taskclass, 0) == 0) {
1311                 return -ENOMEM;
1312         }
1313 #endif
1314
1315         p = copy_process(clone_flags, stack_start, regs, stack_size, parent_tidptr, child_tidptr, pid);
1316         /*
1317          * Do this prior waking up the new thread - the thread pointer
1318          * might get invalid after that point, if the thread exits quickly.
1319          */
1320         if (!IS_ERR(p)) {
1321                 struct completion vfork;
1322
1323                 ckrm_cb_fork(p);
1324
1325                 if (clone_flags & CLONE_VFORK) {
1326                         p->vfork_done = &vfork;
1327                         init_completion(&vfork);
1328                 }
1329
1330                 if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) {
1331                         /*
1332                          * We'll start up with an immediate SIGSTOP.
1333                          */
1334                         sigaddset(&p->pending.signal, SIGSTOP);
1335                         set_tsk_thread_flag(p, TIF_SIGPENDING);
1336                 }
1337
1338                 if (!(clone_flags & CLONE_STOPPED))
1339                         wake_up_new_task(p, clone_flags);
1340                 else
1341                         p->state = TASK_STOPPED;
1342                 ++total_forks;
1343
1344                 if (unlikely (trace)) {
1345                         current->ptrace_message = pid;
1346                         ptrace_notify ((trace << 8) | SIGTRAP);
1347                 }
1348
1349                 if (clone_flags & CLONE_VFORK) {
1350                         wait_for_completion(&vfork);
1351                         if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE))
1352                                 ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
1353                 }
1354         } else {
1355 #ifdef CONFIG_CKRM_TYPE_TASKCLASS
1356                 numtasks_put_ref(current->taskclass);
1357 #endif
1358                 free_pidmap(pid);
1359                 pid = PTR_ERR(p);
1360         }
1361         return pid;
1362 }
1363
1364 /* SLAB cache for signal_struct structures (tsk->signal) */
1365 kmem_cache_t *signal_cachep;
1366
1367 /* SLAB cache for sighand_struct structures (tsk->sighand) */
1368 kmem_cache_t *sighand_cachep;
1369
1370 /* SLAB cache for files_struct structures (tsk->files) */
1371 kmem_cache_t *files_cachep;
1372
1373 /* SLAB cache for fs_struct structures (tsk->fs) */
1374 kmem_cache_t *fs_cachep;
1375
1376 /* SLAB cache for vm_area_struct structures */
1377 kmem_cache_t *vm_area_cachep;
1378
1379 /* SLAB cache for mm_struct structures (tsk->mm) */
1380 kmem_cache_t *mm_cachep;
1381
1382 void __init proc_caches_init(void)
1383 {
1384         sighand_cachep = kmem_cache_create("sighand_cache",
1385                         sizeof(struct sighand_struct), 0,
1386                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1387         signal_cachep = kmem_cache_create("signal_cache",
1388                         sizeof(struct signal_struct), 0,
1389                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1390         files_cachep = kmem_cache_create("files_cache",
1391                         sizeof(struct files_struct), 0,
1392                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1393         fs_cachep = kmem_cache_create("fs_cache",
1394                         sizeof(struct fs_struct), 0,
1395                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1396         vm_area_cachep = kmem_cache_create("vm_area_struct",
1397                         sizeof(struct vm_area_struct), 0,
1398                         SLAB_PANIC, NULL, NULL);
1399         mm_cachep = kmem_cache_create("mm_struct",
1400                         sizeof(struct mm_struct), 0,
1401                         SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1402 }