4 * Copyright (C) 1991, 1992 Linus Torvalds
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()'
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/unistd.h>
17 #include <linux/module.h>
18 #include <linux/vmalloc.h>
19 #include <linux/completion.h>
20 #include <linux/mnt_namespace.h>
21 #include <linux/personality.h>
22 #include <linux/mempolicy.h>
23 #include <linux/sem.h>
24 #include <linux/file.h>
25 #include <linux/key.h>
26 #include <linux/binfmts.h>
27 #include <linux/mman.h>
29 #include <linux/nsproxy.h>
30 #include <linux/capability.h>
31 #include <linux/cpu.h>
32 #include <linux/cgroup.h>
33 #include <linux/security.h>
34 #include <linux/swap.h>
35 #include <linux/syscalls.h>
36 #include <linux/jiffies.h>
37 #include <linux/futex.h>
38 #include <linux/task_io_accounting_ops.h>
39 #include <linux/rcupdate.h>
40 #include <linux/ptrace.h>
41 #include <linux/mount.h>
42 #include <linux/audit.h>
43 #include <linux/profile.h>
44 #include <linux/rmap.h>
45 #include <linux/acct.h>
46 #include <linux/tsacct_kern.h>
47 #include <linux/cn_proc.h>
48 #include <linux/freezer.h>
49 #include <linux/delayacct.h>
50 #include <linux/taskstats_kern.h>
51 #include <linux/random.h>
52 #include <linux/tty.h>
53 #include <linux/proc_fs.h>
54 #include <linux/blkdev.h>
56 #include <asm/pgtable.h>
57 #include <asm/pgalloc.h>
58 #include <asm/uaccess.h>
59 #include <asm/mmu_context.h>
60 #include <asm/cacheflush.h>
61 #include <asm/tlbflush.h>
64 * Protected counters by write_lock_irq(&tasklist_lock)
66 unsigned long total_forks; /* Handle normal Linux uptimes. */
67 int nr_threads; /* The idle threads do not count.. */
69 int max_threads; /* tunable limit on nr_threads */
71 DEFINE_PER_CPU(unsigned long, process_counts) = 0;
73 __cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
75 int nr_processes(void)
80 for_each_online_cpu(cpu)
81 total += per_cpu(process_counts, cpu);
86 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
87 # define alloc_task_struct() kmem_cache_alloc(task_struct_cachep, GFP_KERNEL)
88 # define free_task_struct(tsk) kmem_cache_free(task_struct_cachep, (tsk))
89 static struct kmem_cache *task_struct_cachep;
92 /* SLAB cache for signal_struct structures (tsk->signal) */
93 static struct kmem_cache *signal_cachep;
95 /* SLAB cache for sighand_struct structures (tsk->sighand) */
96 struct kmem_cache *sighand_cachep;
98 /* SLAB cache for files_struct structures (tsk->files) */
99 struct kmem_cache *files_cachep;
101 /* SLAB cache for fs_struct structures (tsk->fs) */
102 struct kmem_cache *fs_cachep;
104 /* SLAB cache for vm_area_struct structures */
105 struct kmem_cache *vm_area_cachep;
107 /* SLAB cache for mm_struct structures (tsk->mm) */
108 static struct kmem_cache *mm_cachep;
110 void free_task(struct task_struct *tsk)
112 prop_local_destroy_single(&tsk->dirties);
113 free_thread_info(tsk->stack);
114 rt_mutex_debug_task_free(tsk);
115 free_task_struct(tsk);
117 EXPORT_SYMBOL(free_task);
119 void __put_task_struct(struct task_struct *tsk)
121 WARN_ON(!tsk->exit_state);
122 WARN_ON(atomic_read(&tsk->usage));
123 WARN_ON(tsk == current);
125 security_task_free(tsk);
127 put_group_info(tsk->group_info);
128 delayacct_tsk_free(tsk);
130 if (!profile_handoff_task(tsk))
134 void __init fork_init(unsigned long mempages)
136 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
137 #ifndef ARCH_MIN_TASKALIGN
138 #define ARCH_MIN_TASKALIGN L1_CACHE_BYTES
140 /* create a slab on which task_structs can be allocated */
142 kmem_cache_create("task_struct", sizeof(struct task_struct),
143 ARCH_MIN_TASKALIGN, SLAB_PANIC, NULL);
147 * The default maximum number of threads is set to a safe
148 * value: the thread structures can take up at most half
151 max_threads = mempages / (8 * THREAD_SIZE / PAGE_SIZE);
154 * we need to allow at least 20 threads to boot a system
159 init_task.signal->rlim[RLIMIT_NPROC].rlim_cur = max_threads/2;
160 init_task.signal->rlim[RLIMIT_NPROC].rlim_max = max_threads/2;
161 init_task.signal->rlim[RLIMIT_SIGPENDING] =
162 init_task.signal->rlim[RLIMIT_NPROC];
165 static struct task_struct *dup_task_struct(struct task_struct *orig)
167 struct task_struct *tsk;
168 struct thread_info *ti;
171 prepare_to_copy(orig);
173 tsk = alloc_task_struct();
177 ti = alloc_thread_info(tsk);
179 free_task_struct(tsk);
186 err = prop_local_init_single(&tsk->dirties);
188 free_thread_info(ti);
189 free_task_struct(tsk);
193 setup_thread_stack(tsk, orig);
195 #ifdef CONFIG_CC_STACKPROTECTOR
196 tsk->stack_canary = get_random_int();
199 /* One for us, one for whoever does the "release_task()" (usually parent) */
200 atomic_set(&tsk->usage,2);
201 atomic_set(&tsk->fs_excl, 0);
202 #ifdef CONFIG_BLK_DEV_IO_TRACE
205 tsk->splice_pipe = NULL;
210 static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
212 struct vm_area_struct *mpnt, *tmp, **pprev;
213 struct rb_node **rb_link, *rb_parent;
215 unsigned long charge;
216 struct mempolicy *pol;
218 down_write(&oldmm->mmap_sem);
219 flush_cache_dup_mm(oldmm);
221 * Not linked in yet - no deadlock potential:
223 down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING);
227 mm->mmap_cache = NULL;
228 mm->free_area_cache = oldmm->mmap_base;
229 mm->cached_hole_size = ~0UL;
231 cpus_clear(mm->cpu_vm_mask);
233 rb_link = &mm->mm_rb.rb_node;
237 for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
240 if (mpnt->vm_flags & VM_DONTCOPY) {
241 long pages = vma_pages(mpnt);
242 mm->total_vm -= pages;
243 vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file,
248 if (mpnt->vm_flags & VM_ACCOUNT) {
249 unsigned int len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
250 if (security_vm_enough_memory(len))
254 tmp = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
258 pol = mpol_copy(vma_policy(mpnt));
259 retval = PTR_ERR(pol);
261 goto fail_nomem_policy;
262 vma_set_policy(tmp, pol);
263 tmp->vm_flags &= ~VM_LOCKED;
269 struct inode *inode = file->f_path.dentry->d_inode;
271 if (tmp->vm_flags & VM_DENYWRITE)
272 atomic_dec(&inode->i_writecount);
274 /* insert tmp into the share list, just after mpnt */
275 spin_lock(&file->f_mapping->i_mmap_lock);
276 tmp->vm_truncate_count = mpnt->vm_truncate_count;
277 flush_dcache_mmap_lock(file->f_mapping);
278 vma_prio_tree_add(tmp, mpnt);
279 flush_dcache_mmap_unlock(file->f_mapping);
280 spin_unlock(&file->f_mapping->i_mmap_lock);
284 * Link in the new vma and copy the page table entries.
287 pprev = &tmp->vm_next;
289 __vma_link_rb(mm, tmp, rb_link, rb_parent);
290 rb_link = &tmp->vm_rb.rb_right;
291 rb_parent = &tmp->vm_rb;
294 retval = copy_page_range(mm, oldmm, mpnt);
296 if (tmp->vm_ops && tmp->vm_ops->open)
297 tmp->vm_ops->open(tmp);
302 /* a new mm has just been created */
303 arch_dup_mmap(oldmm, mm);
306 up_write(&mm->mmap_sem);
308 up_write(&oldmm->mmap_sem);
311 kmem_cache_free(vm_area_cachep, tmp);
314 vm_unacct_memory(charge);
318 static inline int mm_alloc_pgd(struct mm_struct * mm)
320 mm->pgd = pgd_alloc(mm);
321 if (unlikely(!mm->pgd))
326 static inline void mm_free_pgd(struct mm_struct * mm)
331 #define dup_mmap(mm, oldmm) (0)
332 #define mm_alloc_pgd(mm) (0)
333 #define mm_free_pgd(mm)
334 #endif /* CONFIG_MMU */
336 __cacheline_aligned_in_smp DEFINE_SPINLOCK(mmlist_lock);
338 #define allocate_mm() (kmem_cache_alloc(mm_cachep, GFP_KERNEL))
339 #define free_mm(mm) (kmem_cache_free(mm_cachep, (mm)))
341 #include <linux/init_task.h>
343 static struct mm_struct * mm_init(struct mm_struct * mm)
345 atomic_set(&mm->mm_users, 1);
346 atomic_set(&mm->mm_count, 1);
347 init_rwsem(&mm->mmap_sem);
348 INIT_LIST_HEAD(&mm->mmlist);
349 mm->flags = (current->mm) ? current->mm->flags
350 : MMF_DUMP_FILTER_DEFAULT;
351 mm->core_waiters = 0;
353 set_mm_counter(mm, file_rss, 0);
354 set_mm_counter(mm, anon_rss, 0);
355 spin_lock_init(&mm->page_table_lock);
356 rwlock_init(&mm->ioctx_list_lock);
357 mm->ioctx_list = NULL;
358 mm->free_area_cache = TASK_UNMAPPED_BASE;
359 mm->cached_hole_size = ~0UL;
361 if (likely(!mm_alloc_pgd(mm))) {
370 * Allocate and initialize an mm_struct.
372 struct mm_struct * mm_alloc(void)
374 struct mm_struct * mm;
378 memset(mm, 0, sizeof(*mm));
385 * Called when the last reference to the mm
386 * is dropped: either by a lazy thread or by
387 * mmput. Free the page directory and the mm.
389 void fastcall __mmdrop(struct mm_struct *mm)
391 BUG_ON(mm == &init_mm);
398 * Decrement the use count and release all resources for an mm.
400 void mmput(struct mm_struct *mm)
404 if (atomic_dec_and_test(&mm->mm_users)) {
407 if (!list_empty(&mm->mmlist)) {
408 spin_lock(&mmlist_lock);
409 list_del(&mm->mmlist);
410 spin_unlock(&mmlist_lock);
416 EXPORT_SYMBOL_GPL(mmput);
419 * get_task_mm - acquire a reference to the task's mm
421 * Returns %NULL if the task has no mm. Checks PF_BORROWED_MM (meaning
422 * this kernel workthread has transiently adopted a user mm with use_mm,
423 * to do its AIO) is not set and if so returns a reference to it, after
424 * bumping up the use count. User must release the mm via mmput()
425 * after use. Typically used by /proc and ptrace.
427 struct mm_struct *get_task_mm(struct task_struct *task)
429 struct mm_struct *mm;
434 if (task->flags & PF_BORROWED_MM)
437 atomic_inc(&mm->mm_users);
442 EXPORT_SYMBOL_GPL(get_task_mm);
444 /* Please note the differences between mmput and mm_release.
445 * mmput is called whenever we stop holding onto a mm_struct,
446 * error success whatever.
448 * mm_release is called after a mm_struct has been removed
449 * from the current process.
451 * This difference is important for error handling, when we
452 * only half set up a mm_struct for a new process and need to restore
453 * the old one. Because we mmput the new mm_struct before
454 * restoring the old one. . .
455 * Eric Biederman 10 January 1998
457 void mm_release(struct task_struct *tsk, struct mm_struct *mm)
459 struct completion *vfork_done = tsk->vfork_done;
461 /* Get rid of any cached register state */
462 deactivate_mm(tsk, mm);
464 /* notify parent sleeping on vfork() */
466 tsk->vfork_done = NULL;
467 complete(vfork_done);
471 * If we're exiting normally, clear a user-space tid field if
472 * requested. We leave this alone when dying by signal, to leave
473 * the value intact in a core dump, and to save the unnecessary
474 * trouble otherwise. Userland only wants this done for a sys_exit.
476 if (tsk->clear_child_tid
477 && !(tsk->flags & PF_SIGNALED)
478 && atomic_read(&mm->mm_users) > 1) {
479 u32 __user * tidptr = tsk->clear_child_tid;
480 tsk->clear_child_tid = NULL;
483 * We don't check the error code - if userspace has
484 * not set up a proper pointer then tough luck.
487 sys_futex(tidptr, FUTEX_WAKE, 1, NULL, NULL, 0);
492 * Allocate a new mm structure and copy contents from the
493 * mm structure of the passed in task structure.
495 static struct mm_struct *dup_mm(struct task_struct *tsk)
497 struct mm_struct *mm, *oldmm = current->mm;
507 memcpy(mm, oldmm, sizeof(*mm));
509 /* Initializing for Swap token stuff */
510 mm->token_priority = 0;
511 mm->last_interval = 0;
516 if (init_new_context(tsk, mm))
519 err = dup_mmap(mm, oldmm);
523 mm->hiwater_rss = get_mm_rss(mm);
524 mm->hiwater_vm = mm->total_vm;
536 * If init_new_context() failed, we cannot use mmput() to free the mm
537 * because it calls destroy_context()
544 static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
546 struct mm_struct * mm, *oldmm;
549 tsk->min_flt = tsk->maj_flt = 0;
550 tsk->nvcsw = tsk->nivcsw = 0;
553 tsk->active_mm = NULL;
556 * Are we cloning a kernel thread?
558 * We need to steal a active VM for that..
564 if (clone_flags & CLONE_VM) {
565 atomic_inc(&oldmm->mm_users);
576 /* Initializing for Swap token stuff */
577 mm->token_priority = 0;
578 mm->last_interval = 0;
588 static struct fs_struct *__copy_fs_struct(struct fs_struct *old)
590 struct fs_struct *fs = kmem_cache_alloc(fs_cachep, GFP_KERNEL);
591 /* We don't need to lock fs - think why ;-) */
593 atomic_set(&fs->count, 1);
594 rwlock_init(&fs->lock);
595 fs->umask = old->umask;
596 read_lock(&old->lock);
597 fs->rootmnt = mntget(old->rootmnt);
598 fs->root = dget(old->root);
599 fs->pwdmnt = mntget(old->pwdmnt);
600 fs->pwd = dget(old->pwd);
602 fs->altrootmnt = mntget(old->altrootmnt);
603 fs->altroot = dget(old->altroot);
605 fs->altrootmnt = NULL;
608 read_unlock(&old->lock);
613 struct fs_struct *copy_fs_struct(struct fs_struct *old)
615 return __copy_fs_struct(old);
618 EXPORT_SYMBOL_GPL(copy_fs_struct);
620 static int copy_fs(unsigned long clone_flags, struct task_struct *tsk)
622 if (clone_flags & CLONE_FS) {
623 atomic_inc(¤t->fs->count);
626 tsk->fs = __copy_fs_struct(current->fs);
632 static int count_open_files(struct fdtable *fdt)
634 int size = fdt->max_fds;
637 /* Find the last open fd */
638 for (i = size/(8*sizeof(long)); i > 0; ) {
639 if (fdt->open_fds->fds_bits[--i])
642 i = (i+1) * 8 * sizeof(long);
646 static struct files_struct *alloc_files(void)
648 struct files_struct *newf;
651 newf = kmem_cache_alloc(files_cachep, GFP_KERNEL);
655 atomic_set(&newf->count, 1);
657 spin_lock_init(&newf->file_lock);
660 fdt->max_fds = NR_OPEN_DEFAULT;
661 fdt->close_on_exec = (fd_set *)&newf->close_on_exec_init;
662 fdt->open_fds = (fd_set *)&newf->open_fds_init;
663 fdt->fd = &newf->fd_array[0];
664 INIT_RCU_HEAD(&fdt->rcu);
666 rcu_assign_pointer(newf->fdt, fdt);
672 * Allocate a new files structure and copy contents from the
673 * passed in files structure.
674 * errorp will be valid only when the returned files_struct is NULL.
676 static struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)
678 struct files_struct *newf;
679 struct file **old_fds, **new_fds;
680 int open_files, size, i;
681 struct fdtable *old_fdt, *new_fdt;
684 newf = alloc_files();
688 spin_lock(&oldf->file_lock);
689 old_fdt = files_fdtable(oldf);
690 new_fdt = files_fdtable(newf);
691 open_files = count_open_files(old_fdt);
694 * Check whether we need to allocate a larger fd array and fd set.
695 * Note: we're not a clone task, so the open count won't change.
697 if (open_files > new_fdt->max_fds) {
698 new_fdt->max_fds = 0;
699 spin_unlock(&oldf->file_lock);
700 spin_lock(&newf->file_lock);
701 *errorp = expand_files(newf, open_files-1);
702 spin_unlock(&newf->file_lock);
705 new_fdt = files_fdtable(newf);
707 * Reacquire the oldf lock and a pointer to its fd table
708 * who knows it may have a new bigger fd table. We need
709 * the latest pointer.
711 spin_lock(&oldf->file_lock);
712 old_fdt = files_fdtable(oldf);
715 old_fds = old_fdt->fd;
716 new_fds = new_fdt->fd;
718 memcpy(new_fdt->open_fds->fds_bits,
719 old_fdt->open_fds->fds_bits, open_files/8);
720 memcpy(new_fdt->close_on_exec->fds_bits,
721 old_fdt->close_on_exec->fds_bits, open_files/8);
723 for (i = open_files; i != 0; i--) {
724 struct file *f = *old_fds++;
729 * The fd may be claimed in the fd bitmap but not yet
730 * instantiated in the files array if a sibling thread
731 * is partway through open(). So make sure that this
732 * fd is available to the new process.
734 FD_CLR(open_files - i, new_fdt->open_fds);
736 rcu_assign_pointer(*new_fds++, f);
738 spin_unlock(&oldf->file_lock);
740 /* compute the remainder to be cleared */
741 size = (new_fdt->max_fds - open_files) * sizeof(struct file *);
743 /* This is long word aligned thus could use a optimized version */
744 memset(new_fds, 0, size);
746 if (new_fdt->max_fds > open_files) {
747 int left = (new_fdt->max_fds-open_files)/8;
748 int start = open_files / (8 * sizeof(unsigned long));
750 memset(&new_fdt->open_fds->fds_bits[start], 0, left);
751 memset(&new_fdt->close_on_exec->fds_bits[start], 0, left);
757 kmem_cache_free(files_cachep, newf);
762 static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
764 struct files_struct *oldf, *newf;
768 * A background process may not have any files ...
770 oldf = current->files;
774 if (clone_flags & CLONE_FILES) {
775 atomic_inc(&oldf->count);
780 * Note: we may be using current for both targets (See exec.c)
781 * This works because we cache current->files (old) as oldf. Don't
785 newf = dup_fd(oldf, &error);
795 static int copy_io(struct task_struct *tsk)
798 struct io_context *ioc = current->io_context;
803 if (ioprio_valid(ioc->ioprio)) {
804 tsk->io_context = alloc_io_context(GFP_KERNEL, -1);
805 if (unlikely(!tsk->io_context))
808 tsk->io_context->ioprio = ioc->ioprio;
815 * Helper to unshare the files of the current task.
816 * We don't want to expose copy_files internals to
817 * the exec layer of the kernel.
820 int unshare_files(void)
822 struct files_struct *files = current->files;
827 /* This can race but the race causes us to copy when we don't
828 need to and drop the copy */
829 if(atomic_read(&files->count) == 1)
831 atomic_inc(&files->count);
834 rc = copy_files(0, current);
836 current->files = files;
840 EXPORT_SYMBOL(unshare_files);
842 static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk)
844 struct sighand_struct *sig;
846 if (clone_flags & (CLONE_SIGHAND | CLONE_THREAD)) {
847 atomic_inc(¤t->sighand->count);
850 sig = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
851 rcu_assign_pointer(tsk->sighand, sig);
854 atomic_set(&sig->count, 1);
855 memcpy(sig->action, current->sighand->action, sizeof(sig->action));
859 void __cleanup_sighand(struct sighand_struct *sighand)
861 if (atomic_dec_and_test(&sighand->count))
862 kmem_cache_free(sighand_cachep, sighand);
865 static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
867 struct signal_struct *sig;
870 if (clone_flags & CLONE_THREAD) {
871 atomic_inc(¤t->signal->count);
872 atomic_inc(¤t->signal->live);
875 sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
880 ret = copy_thread_group_keys(tsk);
882 kmem_cache_free(signal_cachep, sig);
886 atomic_set(&sig->count, 1);
887 atomic_set(&sig->live, 1);
888 init_waitqueue_head(&sig->wait_chldexit);
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);
897 hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
898 sig->it_real_incr.tv64 = 0;
899 sig->real_timer.function = it_real_fn;
902 sig->it_virt_expires = cputime_zero;
903 sig->it_virt_incr = cputime_zero;
904 sig->it_prof_expires = cputime_zero;
905 sig->it_prof_incr = cputime_zero;
907 sig->leader = 0; /* session leadership doesn't inherit */
908 sig->tty_old_pgrp = NULL;
910 sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero;
911 sig->gtime = cputime_zero;
912 sig->cgtime = cputime_zero;
913 sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
914 sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
915 sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0;
916 sig->sum_sched_runtime = 0;
917 INIT_LIST_HEAD(&sig->cpu_timers[0]);
918 INIT_LIST_HEAD(&sig->cpu_timers[1]);
919 INIT_LIST_HEAD(&sig->cpu_timers[2]);
920 taskstats_tgid_init(sig);
922 task_lock(current->group_leader);
923 memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim);
924 task_unlock(current->group_leader);
926 if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
928 * New sole thread in the process gets an expiry time
929 * of the whole CPU time limit.
931 tsk->it_prof_expires =
932 secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
934 acct_init_pacct(&sig->pacct);
941 void __cleanup_signal(struct signal_struct *sig)
943 exit_thread_group_keys(sig);
944 kmem_cache_free(signal_cachep, sig);
947 static void cleanup_signal(struct task_struct *tsk)
949 struct signal_struct *sig = tsk->signal;
951 atomic_dec(&sig->live);
953 if (atomic_dec_and_test(&sig->count))
954 __cleanup_signal(sig);
957 static void copy_flags(unsigned long clone_flags, struct task_struct *p)
959 unsigned long new_flags = p->flags;
961 new_flags &= ~PF_SUPERPRIV;
962 new_flags |= PF_FORKNOEXEC;
963 if (!(clone_flags & CLONE_PTRACE))
965 p->flags = new_flags;
966 clear_freeze_flag(p);
969 asmlinkage long sys_set_tid_address(int __user *tidptr)
971 current->clear_child_tid = tidptr;
973 return task_pid_vnr(current);
976 static void rt_mutex_init_task(struct task_struct *p)
978 spin_lock_init(&p->pi_lock);
979 #ifdef CONFIG_RT_MUTEXES
980 plist_head_init(&p->pi_waiters, &p->pi_lock);
981 p->pi_blocked_on = NULL;
986 * This creates a new process as a copy of the old one,
987 * but does not actually start it yet.
989 * It copies the registers, and all the appropriate
990 * parts of the process environment (as per the clone
991 * flags). The actual kick-off is left to the caller.
993 static struct task_struct *copy_process(unsigned long clone_flags,
994 unsigned long stack_start,
995 struct pt_regs *regs,
996 unsigned long stack_size,
997 int __user *child_tidptr,
1001 struct task_struct *p;
1002 int cgroup_callbacks_done = 0;
1004 if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
1005 return ERR_PTR(-EINVAL);
1008 * Thread groups must share signals as well, and detached threads
1009 * can only be started up within the thread group.
1011 if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
1012 return ERR_PTR(-EINVAL);
1015 * Shared signal handlers imply shared VM. By way of the above,
1016 * thread groups also imply shared VM. Blocking this case allows
1017 * for various simplifications in other code.
1019 if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
1020 return ERR_PTR(-EINVAL);
1022 retval = security_task_create(clone_flags);
1027 p = dup_task_struct(current);
1031 rt_mutex_init_task(p);
1033 #ifdef CONFIG_TRACE_IRQFLAGS
1034 DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
1035 DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
1038 if (atomic_read(&p->user->processes) >=
1039 p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
1040 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
1041 p->user != current->nsproxy->user_ns->root_user)
1045 atomic_inc(&p->user->__count);
1046 atomic_inc(&p->user->processes);
1047 get_group_info(p->group_info);
1050 * If multiple threads are within copy_process(), then this check
1051 * triggers too late. This doesn't hurt, the check is only there
1052 * to stop root fork bombs.
1054 if (nr_threads >= max_threads)
1055 goto bad_fork_cleanup_count;
1057 if (!try_module_get(task_thread_info(p)->exec_domain->module))
1058 goto bad_fork_cleanup_count;
1060 if (p->binfmt && !try_module_get(p->binfmt->module))
1061 goto bad_fork_cleanup_put_domain;
1064 delayacct_tsk_init(p); /* Must remain after dup_task_struct() */
1065 copy_flags(clone_flags, p);
1066 INIT_LIST_HEAD(&p->children);
1067 INIT_LIST_HEAD(&p->sibling);
1068 #ifdef CONFIG_PREEMPT_RCU
1069 p->rcu_read_lock_nesting = 0;
1070 p->rcu_flipctr_idx = 0;
1071 #endif /* #ifdef CONFIG_PREEMPT_RCU */
1072 p->vfork_done = NULL;
1073 spin_lock_init(&p->alloc_lock);
1075 clear_tsk_thread_flag(p, TIF_SIGPENDING);
1076 init_sigpending(&p->pending);
1078 p->utime = cputime_zero;
1079 p->stime = cputime_zero;
1080 p->gtime = cputime_zero;
1081 p->utimescaled = cputime_zero;
1082 p->stimescaled = cputime_zero;
1083 p->prev_utime = cputime_zero;
1084 p->prev_stime = cputime_zero;
1086 #ifdef CONFIG_DETECT_SOFTLOCKUP
1087 p->last_switch_count = 0;
1088 p->last_switch_timestamp = 0;
1091 #ifdef CONFIG_TASK_XACCT
1092 p->rchar = 0; /* I/O counter: bytes read */
1093 p->wchar = 0; /* I/O counter: bytes written */
1094 p->syscr = 0; /* I/O counter: read syscalls */
1095 p->syscw = 0; /* I/O counter: write syscalls */
1097 task_io_accounting_init(p);
1098 acct_clear_integrals(p);
1100 p->it_virt_expires = cputime_zero;
1101 p->it_prof_expires = cputime_zero;
1102 p->it_sched_expires = 0;
1103 INIT_LIST_HEAD(&p->cpu_timers[0]);
1104 INIT_LIST_HEAD(&p->cpu_timers[1]);
1105 INIT_LIST_HEAD(&p->cpu_timers[2]);
1107 p->lock_depth = -1; /* -1 = no lock */
1108 do_posix_clock_monotonic_gettime(&p->start_time);
1109 p->real_start_time = p->start_time;
1110 monotonic_to_bootbased(&p->real_start_time);
1111 #ifdef CONFIG_SECURITY
1114 p->io_context = NULL;
1115 p->audit_context = NULL;
1118 p->mempolicy = mpol_copy(p->mempolicy);
1119 if (IS_ERR(p->mempolicy)) {
1120 retval = PTR_ERR(p->mempolicy);
1121 p->mempolicy = NULL;
1122 goto bad_fork_cleanup_cgroup;
1124 mpol_fix_fork_child_flag(p);
1126 #ifdef CONFIG_TRACE_IRQFLAGS
1128 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
1129 p->hardirqs_enabled = 1;
1131 p->hardirqs_enabled = 0;
1133 p->hardirq_enable_ip = 0;
1134 p->hardirq_enable_event = 0;
1135 p->hardirq_disable_ip = _THIS_IP_;
1136 p->hardirq_disable_event = 0;
1137 p->softirqs_enabled = 1;
1138 p->softirq_enable_ip = _THIS_IP_;
1139 p->softirq_enable_event = 0;
1140 p->softirq_disable_ip = 0;
1141 p->softirq_disable_event = 0;
1142 p->hardirq_context = 0;
1143 p->softirq_context = 0;
1145 #ifdef CONFIG_LOCKDEP
1146 p->lockdep_depth = 0; /* no locks held yet */
1147 p->curr_chain_key = 0;
1148 p->lockdep_recursion = 0;
1151 #ifdef CONFIG_DEBUG_MUTEXES
1152 p->blocked_on = NULL; /* not blocked yet */
1155 /* Perform scheduler related setup. Assign this task to a CPU. */
1156 sched_fork(p, clone_flags);
1158 if ((retval = security_task_alloc(p)))
1159 goto bad_fork_cleanup_policy;
1160 if ((retval = audit_alloc(p)))
1161 goto bad_fork_cleanup_security;
1162 /* copy all the process information */
1163 if ((retval = copy_semundo(clone_flags, p)))
1164 goto bad_fork_cleanup_audit;
1165 if ((retval = copy_files(clone_flags, p)))
1166 goto bad_fork_cleanup_semundo;
1167 if ((retval = copy_fs(clone_flags, p)))
1168 goto bad_fork_cleanup_files;
1169 if ((retval = copy_sighand(clone_flags, p)))
1170 goto bad_fork_cleanup_fs;
1171 if ((retval = copy_signal(clone_flags, p)))
1172 goto bad_fork_cleanup_sighand;
1173 if ((retval = copy_mm(clone_flags, p)))
1174 goto bad_fork_cleanup_signal;
1175 if ((retval = copy_keys(clone_flags, p)))
1176 goto bad_fork_cleanup_mm;
1177 if ((retval = copy_namespaces(clone_flags, p)))
1178 goto bad_fork_cleanup_keys;
1179 if ((retval = copy_io(p)))
1180 goto bad_fork_cleanup_namespaces;
1181 retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
1183 goto bad_fork_cleanup_io;
1185 if (pid != &init_struct_pid) {
1187 pid = alloc_pid(task_active_pid_ns(p));
1189 goto bad_fork_cleanup_io;
1191 if (clone_flags & CLONE_NEWPID) {
1192 retval = pid_ns_prepare_proc(task_active_pid_ns(p));
1194 goto bad_fork_free_pid;
1198 p->pid = pid_nr(pid);
1200 if (clone_flags & CLONE_THREAD)
1201 p->tgid = current->tgid;
1203 p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
1205 * Clear TID on mm_release()?
1207 p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
1209 p->robust_list = NULL;
1210 #ifdef CONFIG_COMPAT
1211 p->compat_robust_list = NULL;
1213 INIT_LIST_HEAD(&p->pi_state_list);
1214 p->pi_state_cache = NULL;
1217 * sigaltstack should be cleared when sharing the same VM
1219 if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM)
1220 p->sas_ss_sp = p->sas_ss_size = 0;
1223 * Syscall tracing should be turned off in the child regardless
1226 clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
1227 #ifdef TIF_SYSCALL_EMU
1228 clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
1230 clear_all_latency_tracing(p);
1232 /* Our parent execution domain becomes current domain
1233 These must match for thread signalling to apply */
1234 p->parent_exec_id = p->self_exec_id;
1236 /* ok, now we should be set up.. */
1237 p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
1238 p->pdeath_signal = 0;
1242 * Ok, make it visible to the rest of the system.
1243 * We dont wake it up yet.
1245 p->group_leader = p;
1246 INIT_LIST_HEAD(&p->thread_group);
1247 INIT_LIST_HEAD(&p->ptrace_children);
1248 INIT_LIST_HEAD(&p->ptrace_list);
1250 /* Now that the task is set up, run cgroup callbacks if
1251 * necessary. We need to run them before the task is visible
1252 * on the tasklist. */
1253 cgroup_fork_callbacks(p);
1254 cgroup_callbacks_done = 1;
1256 /* Need tasklist lock for parent etc handling! */
1257 write_lock_irq(&tasklist_lock);
1260 * The task hasn't been attached yet, so its cpus_allowed mask will
1261 * not be changed, nor will its assigned CPU.
1263 * The cpus_allowed mask of the parent may have changed after it was
1264 * copied first time - so re-copy it here, then check the child's CPU
1265 * to ensure it is on a valid CPU (and if not, just force it back to
1266 * parent's CPU). This avoids alot of nasty races.
1268 p->cpus_allowed = current->cpus_allowed;
1269 p->rt.nr_cpus_allowed = current->rt.nr_cpus_allowed;
1270 if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) ||
1271 !cpu_online(task_cpu(p))))
1272 set_task_cpu(p, smp_processor_id());
1274 /* CLONE_PARENT re-uses the old parent */
1275 if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
1276 p->real_parent = current->real_parent;
1278 p->real_parent = current;
1279 p->parent = p->real_parent;
1281 spin_lock(¤t->sighand->siglock);
1284 * Process group and session signals need to be delivered to just the
1285 * parent before the fork or both the parent and the child after the
1286 * fork. Restart if a signal comes in before we add the new process to
1287 * it's process group.
1288 * A fatal signal pending means that current will exit, so the new
1289 * thread can't slip out of an OOM kill (or normal SIGKILL).
1291 recalc_sigpending();
1292 if (signal_pending(current)) {
1293 spin_unlock(¤t->sighand->siglock);
1294 write_unlock_irq(&tasklist_lock);
1295 retval = -ERESTARTNOINTR;
1296 goto bad_fork_free_pid;
1299 if (clone_flags & CLONE_THREAD) {
1300 p->group_leader = current->group_leader;
1301 list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
1303 if (!cputime_eq(current->signal->it_virt_expires,
1305 !cputime_eq(current->signal->it_prof_expires,
1307 current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY ||
1308 !list_empty(¤t->signal->cpu_timers[0]) ||
1309 !list_empty(¤t->signal->cpu_timers[1]) ||
1310 !list_empty(¤t->signal->cpu_timers[2])) {
1312 * Have child wake up on its first tick to check
1313 * for process CPU timers.
1315 p->it_prof_expires = jiffies_to_cputime(1);
1319 if (likely(p->pid)) {
1321 if (unlikely(p->ptrace & PT_PTRACED))
1322 __ptrace_link(p, current->parent);
1324 if (thread_group_leader(p)) {
1325 if (clone_flags & CLONE_NEWPID)
1326 p->nsproxy->pid_ns->child_reaper = p;
1328 p->signal->tty = current->signal->tty;
1329 set_task_pgrp(p, task_pgrp_nr(current));
1330 set_task_session(p, task_session_nr(current));
1331 attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
1332 attach_pid(p, PIDTYPE_SID, task_session(current));
1333 list_add_tail_rcu(&p->tasks, &init_task.tasks);
1334 __get_cpu_var(process_counts)++;
1336 attach_pid(p, PIDTYPE_PID, pid);
1341 spin_unlock(¤t->sighand->siglock);
1342 write_unlock_irq(&tasklist_lock);
1343 proc_fork_connector(p);
1344 cgroup_post_fork(p);
1348 if (pid != &init_struct_pid)
1350 bad_fork_cleanup_io:
1351 put_io_context(p->io_context);
1352 bad_fork_cleanup_namespaces:
1353 exit_task_namespaces(p);
1354 bad_fork_cleanup_keys:
1356 bad_fork_cleanup_mm:
1359 bad_fork_cleanup_signal:
1361 bad_fork_cleanup_sighand:
1362 __cleanup_sighand(p->sighand);
1363 bad_fork_cleanup_fs:
1364 exit_fs(p); /* blocking */
1365 bad_fork_cleanup_files:
1366 exit_files(p); /* blocking */
1367 bad_fork_cleanup_semundo:
1369 bad_fork_cleanup_audit:
1371 bad_fork_cleanup_security:
1372 security_task_free(p);
1373 bad_fork_cleanup_policy:
1375 mpol_free(p->mempolicy);
1376 bad_fork_cleanup_cgroup:
1378 cgroup_exit(p, cgroup_callbacks_done);
1379 delayacct_tsk_free(p);
1381 module_put(p->binfmt->module);
1382 bad_fork_cleanup_put_domain:
1383 module_put(task_thread_info(p)->exec_domain->module);
1384 bad_fork_cleanup_count:
1385 put_group_info(p->group_info);
1386 atomic_dec(&p->user->processes);
1391 return ERR_PTR(retval);
1394 noinline struct pt_regs * __devinit __attribute__((weak)) idle_regs(struct pt_regs *regs)
1396 memset(regs, 0, sizeof(struct pt_regs));
1400 struct task_struct * __cpuinit fork_idle(int cpu)
1402 struct task_struct *task;
1403 struct pt_regs regs;
1405 task = copy_process(CLONE_VM, 0, idle_regs(®s), 0, NULL,
1408 init_idle(task, cpu);
1413 static int fork_traceflag(unsigned clone_flags)
1415 if (clone_flags & CLONE_UNTRACED)
1417 else if (clone_flags & CLONE_VFORK) {
1418 if (current->ptrace & PT_TRACE_VFORK)
1419 return PTRACE_EVENT_VFORK;
1420 } else if ((clone_flags & CSIGNAL) != SIGCHLD) {
1421 if (current->ptrace & PT_TRACE_CLONE)
1422 return PTRACE_EVENT_CLONE;
1423 } else if (current->ptrace & PT_TRACE_FORK)
1424 return PTRACE_EVENT_FORK;
1430 * Ok, this is the main fork-routine.
1432 * It copies the process, and if successful kick-starts
1433 * it and waits for it to finish using the VM if required.
1435 long do_fork(unsigned long clone_flags,
1436 unsigned long stack_start,
1437 struct pt_regs *regs,
1438 unsigned long stack_size,
1439 int __user *parent_tidptr,
1440 int __user *child_tidptr)
1442 struct task_struct *p;
1446 if (unlikely(current->ptrace)) {
1447 trace = fork_traceflag (clone_flags);
1449 clone_flags |= CLONE_PTRACE;
1452 p = copy_process(clone_flags, stack_start, regs, stack_size,
1453 child_tidptr, NULL);
1455 * Do this prior waking up the new thread - the thread pointer
1456 * might get invalid after that point, if the thread exits quickly.
1459 struct completion vfork;
1462 * this is enough to call pid_nr_ns here, but this if
1463 * improves optimisation of regular fork()
1465 nr = (clone_flags & CLONE_NEWPID) ?
1466 task_pid_nr_ns(p, current->nsproxy->pid_ns) :
1469 if (clone_flags & CLONE_PARENT_SETTID)
1470 put_user(nr, parent_tidptr);
1472 if (clone_flags & CLONE_VFORK) {
1473 p->vfork_done = &vfork;
1474 init_completion(&vfork);
1477 if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) {
1479 * We'll start up with an immediate SIGSTOP.
1481 sigaddset(&p->pending.signal, SIGSTOP);
1482 set_tsk_thread_flag(p, TIF_SIGPENDING);
1485 if (!(clone_flags & CLONE_STOPPED))
1486 wake_up_new_task(p, clone_flags);
1488 p->state = TASK_STOPPED;
1490 if (unlikely (trace)) {
1491 current->ptrace_message = nr;
1492 ptrace_notify ((trace << 8) | SIGTRAP);
1495 if (clone_flags & CLONE_VFORK) {
1496 freezer_do_not_count();
1497 wait_for_completion(&vfork);
1499 if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE)) {
1500 current->ptrace_message = nr;
1501 ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
1510 #ifndef ARCH_MIN_MMSTRUCT_ALIGN
1511 #define ARCH_MIN_MMSTRUCT_ALIGN 0
1514 static void sighand_ctor(struct kmem_cache *cachep, void *data)
1516 struct sighand_struct *sighand = data;
1518 spin_lock_init(&sighand->siglock);
1519 init_waitqueue_head(&sighand->signalfd_wqh);
1522 void __init proc_caches_init(void)
1524 sighand_cachep = kmem_cache_create("sighand_cache",
1525 sizeof(struct sighand_struct), 0,
1526 SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_DESTROY_BY_RCU,
1528 signal_cachep = kmem_cache_create("signal_cache",
1529 sizeof(struct signal_struct), 0,
1530 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1531 files_cachep = kmem_cache_create("files_cache",
1532 sizeof(struct files_struct), 0,
1533 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1534 fs_cachep = kmem_cache_create("fs_cache",
1535 sizeof(struct fs_struct), 0,
1536 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1537 vm_area_cachep = kmem_cache_create("vm_area_struct",
1538 sizeof(struct vm_area_struct), 0,
1540 mm_cachep = kmem_cache_create("mm_struct",
1541 sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
1542 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1546 * Check constraints on flags passed to the unshare system call and
1547 * force unsharing of additional process context as appropriate.
1549 static void check_unshare_flags(unsigned long *flags_ptr)
1552 * If unsharing a thread from a thread group, must also
1555 if (*flags_ptr & CLONE_THREAD)
1556 *flags_ptr |= CLONE_VM;
1559 * If unsharing vm, must also unshare signal handlers.
1561 if (*flags_ptr & CLONE_VM)
1562 *flags_ptr |= CLONE_SIGHAND;
1565 * If unsharing signal handlers and the task was created
1566 * using CLONE_THREAD, then must unshare the thread
1568 if ((*flags_ptr & CLONE_SIGHAND) &&
1569 (atomic_read(¤t->signal->count) > 1))
1570 *flags_ptr |= CLONE_THREAD;
1573 * If unsharing namespace, must also unshare filesystem information.
1575 if (*flags_ptr & CLONE_NEWNS)
1576 *flags_ptr |= CLONE_FS;
1580 * Unsharing of tasks created with CLONE_THREAD is not supported yet
1582 static int unshare_thread(unsigned long unshare_flags)
1584 if (unshare_flags & CLONE_THREAD)
1591 * Unshare the filesystem structure if it is being shared
1593 static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp)
1595 struct fs_struct *fs = current->fs;
1597 if ((unshare_flags & CLONE_FS) &&
1598 (fs && atomic_read(&fs->count) > 1)) {
1599 *new_fsp = __copy_fs_struct(current->fs);
1608 * Unsharing of sighand is not supported yet
1610 static int unshare_sighand(unsigned long unshare_flags, struct sighand_struct **new_sighp)
1612 struct sighand_struct *sigh = current->sighand;
1614 if ((unshare_flags & CLONE_SIGHAND) && atomic_read(&sigh->count) > 1)
1621 * Unshare vm if it is being shared
1623 static int unshare_vm(unsigned long unshare_flags, struct mm_struct **new_mmp)
1625 struct mm_struct *mm = current->mm;
1627 if ((unshare_flags & CLONE_VM) &&
1628 (mm && atomic_read(&mm->mm_users) > 1)) {
1636 * Unshare file descriptor table if it is being shared
1638 static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp)
1640 struct files_struct *fd = current->files;
1643 if ((unshare_flags & CLONE_FILES) &&
1644 (fd && atomic_read(&fd->count) > 1)) {
1645 *new_fdp = dup_fd(fd, &error);
1654 * Unsharing of semundo for tasks created with CLONE_SYSVSEM is not
1657 static int unshare_semundo(unsigned long unshare_flags, struct sem_undo_list **new_ulistp)
1659 if (unshare_flags & CLONE_SYSVSEM)
1666 * unshare allows a process to 'unshare' part of the process
1667 * context which was originally shared using clone. copy_*
1668 * functions used by do_fork() cannot be used here directly
1669 * because they modify an inactive task_struct that is being
1670 * constructed. Here we are modifying the current, active,
1673 asmlinkage long sys_unshare(unsigned long unshare_flags)
1676 struct fs_struct *fs, *new_fs = NULL;
1677 struct sighand_struct *new_sigh = NULL;
1678 struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
1679 struct files_struct *fd, *new_fd = NULL;
1680 struct sem_undo_list *new_ulist = NULL;
1681 struct nsproxy *new_nsproxy = NULL;
1683 check_unshare_flags(&unshare_flags);
1685 /* Return -EINVAL for all unsupported flags */
1687 if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
1688 CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
1689 CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWUSER|
1691 goto bad_unshare_out;
1693 if ((err = unshare_thread(unshare_flags)))
1694 goto bad_unshare_out;
1695 if ((err = unshare_fs(unshare_flags, &new_fs)))
1696 goto bad_unshare_cleanup_thread;
1697 if ((err = unshare_sighand(unshare_flags, &new_sigh)))
1698 goto bad_unshare_cleanup_fs;
1699 if ((err = unshare_vm(unshare_flags, &new_mm)))
1700 goto bad_unshare_cleanup_sigh;
1701 if ((err = unshare_fd(unshare_flags, &new_fd)))
1702 goto bad_unshare_cleanup_vm;
1703 if ((err = unshare_semundo(unshare_flags, &new_ulist)))
1704 goto bad_unshare_cleanup_fd;
1705 if ((err = unshare_nsproxy_namespaces(unshare_flags, &new_nsproxy,
1707 goto bad_unshare_cleanup_semundo;
1709 if (new_fs || new_mm || new_fd || new_ulist || new_nsproxy) {
1712 switch_task_namespaces(current, new_nsproxy);
1720 current->fs = new_fs;
1726 active_mm = current->active_mm;
1727 current->mm = new_mm;
1728 current->active_mm = new_mm;
1729 activate_mm(active_mm, new_mm);
1734 fd = current->files;
1735 current->files = new_fd;
1739 task_unlock(current);
1743 put_nsproxy(new_nsproxy);
1745 bad_unshare_cleanup_semundo:
1746 bad_unshare_cleanup_fd:
1748 put_files_struct(new_fd);
1750 bad_unshare_cleanup_vm:
1754 bad_unshare_cleanup_sigh:
1756 if (atomic_dec_and_test(&new_sigh->count))
1757 kmem_cache_free(sighand_cachep, new_sigh);
1759 bad_unshare_cleanup_fs:
1761 put_fs_struct(new_fs);
1763 bad_unshare_cleanup_thread: