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/smp_lock.h>
18 #include <linux/module.h>
19 #include <linux/vmalloc.h>
20 #include <linux/completion.h>
21 #include <linux/mnt_namespace.h>
22 #include <linux/personality.h>
23 #include <linux/mempolicy.h>
24 #include <linux/sem.h>
25 #include <linux/file.h>
26 #include <linux/key.h>
27 #include <linux/binfmts.h>
28 #include <linux/mman.h>
30 #include <linux/nsproxy.h>
31 #include <linux/capability.h>
32 #include <linux/cpu.h>
33 #include <linux/cpuset.h>
34 #include <linux/security.h>
35 #include <linux/swap.h>
36 #include <linux/syscalls.h>
37 #include <linux/jiffies.h>
38 #include <linux/futex.h>
39 #include <linux/task_io_accounting_ops.h>
40 #include <linux/rcupdate.h>
41 #include <linux/ptrace.h>
42 #include <linux/mount.h>
43 #include <linux/audit.h>
44 #include <linux/profile.h>
45 #include <linux/rmap.h>
46 #include <linux/acct.h>
47 #include <linux/tsacct_kern.h>
48 #include <linux/cn_proc.h>
49 #include <linux/delayacct.h>
50 #include <linux/taskstats_kern.h>
51 #include <linux/random.h>
53 #include <asm/pgtable.h>
54 #include <asm/pgalloc.h>
55 #include <asm/uaccess.h>
56 #include <asm/mmu_context.h>
57 #include <asm/cacheflush.h>
58 #include <asm/tlbflush.h>
61 * Protected counters by write_lock_irq(&tasklist_lock)
63 unsigned long total_forks; /* Handle normal Linux uptimes. */
64 int nr_threads; /* The idle threads do not count.. */
66 int max_threads; /* tunable limit on nr_threads */
68 DEFINE_PER_CPU(unsigned long, process_counts) = 0;
70 __cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
72 int nr_processes(void)
77 for_each_online_cpu(cpu)
78 total += per_cpu(process_counts, cpu);
83 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
84 # define alloc_task_struct() kmem_cache_alloc(task_struct_cachep, GFP_KERNEL)
85 # define free_task_struct(tsk) kmem_cache_free(task_struct_cachep, (tsk))
86 static struct kmem_cache *task_struct_cachep;
89 /* SLAB cache for signal_struct structures (tsk->signal) */
90 static struct kmem_cache *signal_cachep;
92 /* SLAB cache for sighand_struct structures (tsk->sighand) */
93 struct kmem_cache *sighand_cachep;
95 /* SLAB cache for files_struct structures (tsk->files) */
96 struct kmem_cache *files_cachep;
98 /* SLAB cache for fs_struct structures (tsk->fs) */
99 struct kmem_cache *fs_cachep;
101 /* SLAB cache for vm_area_struct structures */
102 struct kmem_cache *vm_area_cachep;
104 /* SLAB cache for mm_struct structures (tsk->mm) */
105 static struct kmem_cache *mm_cachep;
107 void free_task(struct task_struct *tsk)
109 free_thread_info(tsk->thread_info);
110 rt_mutex_debug_task_free(tsk);
111 free_task_struct(tsk);
113 EXPORT_SYMBOL(free_task);
115 void __put_task_struct(struct task_struct *tsk)
117 WARN_ON(!(tsk->exit_state & (EXIT_DEAD | EXIT_ZOMBIE)));
118 WARN_ON(atomic_read(&tsk->usage));
119 WARN_ON(tsk == current);
121 security_task_free(tsk);
123 put_group_info(tsk->group_info);
124 delayacct_tsk_free(tsk);
126 if (!profile_handoff_task(tsk))
130 void __init fork_init(unsigned long mempages)
132 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
133 #ifndef ARCH_MIN_TASKALIGN
134 #define ARCH_MIN_TASKALIGN L1_CACHE_BYTES
136 /* create a slab on which task_structs can be allocated */
138 kmem_cache_create("task_struct", sizeof(struct task_struct),
139 ARCH_MIN_TASKALIGN, SLAB_PANIC, NULL, NULL);
143 * The default maximum number of threads is set to a safe
144 * value: the thread structures can take up at most half
147 max_threads = mempages / (8 * THREAD_SIZE / PAGE_SIZE);
150 * we need to allow at least 20 threads to boot a system
155 init_task.signal->rlim[RLIMIT_NPROC].rlim_cur = max_threads/2;
156 init_task.signal->rlim[RLIMIT_NPROC].rlim_max = max_threads/2;
157 init_task.signal->rlim[RLIMIT_SIGPENDING] =
158 init_task.signal->rlim[RLIMIT_NPROC];
161 static struct task_struct *dup_task_struct(struct task_struct *orig)
163 struct task_struct *tsk;
164 struct thread_info *ti;
166 prepare_to_copy(orig);
168 tsk = alloc_task_struct();
172 ti = alloc_thread_info(tsk);
174 free_task_struct(tsk);
179 tsk->thread_info = ti;
180 setup_thread_stack(tsk, orig);
182 #ifdef CONFIG_CC_STACKPROTECTOR
183 tsk->stack_canary = get_random_int();
186 /* One for us, one for whoever does the "release_task()" (usually parent) */
187 atomic_set(&tsk->usage,2);
188 atomic_set(&tsk->fs_excl, 0);
189 #ifdef CONFIG_BLK_DEV_IO_TRACE
192 tsk->splice_pipe = NULL;
197 static inline int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
199 struct vm_area_struct *mpnt, *tmp, **pprev;
200 struct rb_node **rb_link, *rb_parent;
202 unsigned long charge;
203 struct mempolicy *pol;
205 down_write(&oldmm->mmap_sem);
206 flush_cache_mm(oldmm);
208 * Not linked in yet - no deadlock potential:
210 down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING);
214 mm->mmap_cache = NULL;
215 mm->free_area_cache = oldmm->mmap_base;
216 mm->cached_hole_size = ~0UL;
218 cpus_clear(mm->cpu_vm_mask);
220 rb_link = &mm->mm_rb.rb_node;
224 for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) {
227 if (mpnt->vm_flags & VM_DONTCOPY) {
228 long pages = vma_pages(mpnt);
229 mm->total_vm -= pages;
230 vm_stat_account(mm, mpnt->vm_flags, mpnt->vm_file,
235 if (mpnt->vm_flags & VM_ACCOUNT) {
236 unsigned int len = (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT;
237 if (security_vm_enough_memory(len))
241 tmp = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
245 pol = mpol_copy(vma_policy(mpnt));
246 retval = PTR_ERR(pol);
248 goto fail_nomem_policy;
249 vma_set_policy(tmp, pol);
250 tmp->vm_flags &= ~VM_LOCKED;
256 struct inode *inode = file->f_path.dentry->d_inode;
258 if (tmp->vm_flags & VM_DENYWRITE)
259 atomic_dec(&inode->i_writecount);
261 /* insert tmp into the share list, just after mpnt */
262 spin_lock(&file->f_mapping->i_mmap_lock);
263 tmp->vm_truncate_count = mpnt->vm_truncate_count;
264 flush_dcache_mmap_lock(file->f_mapping);
265 vma_prio_tree_add(tmp, mpnt);
266 flush_dcache_mmap_unlock(file->f_mapping);
267 spin_unlock(&file->f_mapping->i_mmap_lock);
271 * Link in the new vma and copy the page table entries.
274 pprev = &tmp->vm_next;
276 __vma_link_rb(mm, tmp, rb_link, rb_parent);
277 rb_link = &tmp->vm_rb.rb_right;
278 rb_parent = &tmp->vm_rb;
281 retval = copy_page_range(mm, oldmm, mpnt);
283 if (tmp->vm_ops && tmp->vm_ops->open)
284 tmp->vm_ops->open(tmp);
291 up_write(&mm->mmap_sem);
293 up_write(&oldmm->mmap_sem);
296 kmem_cache_free(vm_area_cachep, tmp);
299 vm_unacct_memory(charge);
303 static inline int mm_alloc_pgd(struct mm_struct * mm)
305 mm->pgd = pgd_alloc(mm);
306 if (unlikely(!mm->pgd))
311 static inline void mm_free_pgd(struct mm_struct * mm)
316 #define dup_mmap(mm, oldmm) (0)
317 #define mm_alloc_pgd(mm) (0)
318 #define mm_free_pgd(mm)
319 #endif /* CONFIG_MMU */
321 __cacheline_aligned_in_smp DEFINE_SPINLOCK(mmlist_lock);
323 #define allocate_mm() (kmem_cache_alloc(mm_cachep, GFP_KERNEL))
324 #define free_mm(mm) (kmem_cache_free(mm_cachep, (mm)))
326 #include <linux/init_task.h>
328 static struct mm_struct * mm_init(struct mm_struct * mm)
330 atomic_set(&mm->mm_users, 1);
331 atomic_set(&mm->mm_count, 1);
332 init_rwsem(&mm->mmap_sem);
333 INIT_LIST_HEAD(&mm->mmlist);
334 mm->core_waiters = 0;
336 set_mm_counter(mm, file_rss, 0);
337 set_mm_counter(mm, anon_rss, 0);
338 spin_lock_init(&mm->page_table_lock);
339 rwlock_init(&mm->ioctx_list_lock);
340 mm->ioctx_list = NULL;
341 mm->free_area_cache = TASK_UNMAPPED_BASE;
342 mm->cached_hole_size = ~0UL;
344 if (likely(!mm_alloc_pgd(mm))) {
353 * Allocate and initialize an mm_struct.
355 struct mm_struct * mm_alloc(void)
357 struct mm_struct * mm;
361 memset(mm, 0, sizeof(*mm));
368 * Called when the last reference to the mm
369 * is dropped: either by a lazy thread or by
370 * mmput. Free the page directory and the mm.
372 void fastcall __mmdrop(struct mm_struct *mm)
374 BUG_ON(mm == &init_mm);
381 * Decrement the use count and release all resources for an mm.
383 void mmput(struct mm_struct *mm)
387 if (atomic_dec_and_test(&mm->mm_users)) {
390 if (!list_empty(&mm->mmlist)) {
391 spin_lock(&mmlist_lock);
392 list_del(&mm->mmlist);
393 spin_unlock(&mmlist_lock);
399 EXPORT_SYMBOL_GPL(mmput);
402 * get_task_mm - acquire a reference to the task's mm
404 * Returns %NULL if the task has no mm. Checks PF_BORROWED_MM (meaning
405 * this kernel workthread has transiently adopted a user mm with use_mm,
406 * to do its AIO) is not set and if so returns a reference to it, after
407 * bumping up the use count. User must release the mm via mmput()
408 * after use. Typically used by /proc and ptrace.
410 struct mm_struct *get_task_mm(struct task_struct *task)
412 struct mm_struct *mm;
417 if (task->flags & PF_BORROWED_MM)
420 atomic_inc(&mm->mm_users);
425 EXPORT_SYMBOL_GPL(get_task_mm);
427 /* Please note the differences between mmput and mm_release.
428 * mmput is called whenever we stop holding onto a mm_struct,
429 * error success whatever.
431 * mm_release is called after a mm_struct has been removed
432 * from the current process.
434 * This difference is important for error handling, when we
435 * only half set up a mm_struct for a new process and need to restore
436 * the old one. Because we mmput the new mm_struct before
437 * restoring the old one. . .
438 * Eric Biederman 10 January 1998
440 void mm_release(struct task_struct *tsk, struct mm_struct *mm)
442 struct completion *vfork_done = tsk->vfork_done;
444 /* Get rid of any cached register state */
445 deactivate_mm(tsk, mm);
447 /* notify parent sleeping on vfork() */
449 tsk->vfork_done = NULL;
450 complete(vfork_done);
454 * If we're exiting normally, clear a user-space tid field if
455 * requested. We leave this alone when dying by signal, to leave
456 * the value intact in a core dump, and to save the unnecessary
457 * trouble otherwise. Userland only wants this done for a sys_exit.
459 if (tsk->clear_child_tid
460 && !(tsk->flags & PF_SIGNALED)
461 && atomic_read(&mm->mm_users) > 1) {
462 u32 __user * tidptr = tsk->clear_child_tid;
463 tsk->clear_child_tid = NULL;
466 * We don't check the error code - if userspace has
467 * not set up a proper pointer then tough luck.
470 sys_futex(tidptr, FUTEX_WAKE, 1, NULL, NULL, 0);
475 * Allocate a new mm structure and copy contents from the
476 * mm structure of the passed in task structure.
478 static struct mm_struct *dup_mm(struct task_struct *tsk)
480 struct mm_struct *mm, *oldmm = current->mm;
490 memcpy(mm, oldmm, sizeof(*mm));
492 /* Initializing for Swap token stuff */
493 mm->token_priority = 0;
494 mm->last_interval = 0;
499 if (init_new_context(tsk, mm))
502 err = dup_mmap(mm, oldmm);
506 mm->hiwater_rss = get_mm_rss(mm);
507 mm->hiwater_vm = mm->total_vm;
519 * If init_new_context() failed, we cannot use mmput() to free the mm
520 * because it calls destroy_context()
527 static int copy_mm(unsigned long clone_flags, struct task_struct * tsk)
529 struct mm_struct * mm, *oldmm;
532 tsk->min_flt = tsk->maj_flt = 0;
533 tsk->nvcsw = tsk->nivcsw = 0;
536 tsk->active_mm = NULL;
539 * Are we cloning a kernel thread?
541 * We need to steal a active VM for that..
547 if (clone_flags & CLONE_VM) {
548 atomic_inc(&oldmm->mm_users);
559 /* Initializing for Swap token stuff */
560 mm->token_priority = 0;
561 mm->last_interval = 0;
571 static inline struct fs_struct *__copy_fs_struct(struct fs_struct *old)
573 struct fs_struct *fs = kmem_cache_alloc(fs_cachep, GFP_KERNEL);
574 /* We don't need to lock fs - think why ;-) */
576 atomic_set(&fs->count, 1);
577 rwlock_init(&fs->lock);
578 fs->umask = old->umask;
579 read_lock(&old->lock);
580 fs->rootmnt = mntget(old->rootmnt);
581 fs->root = dget(old->root);
582 fs->pwdmnt = mntget(old->pwdmnt);
583 fs->pwd = dget(old->pwd);
585 fs->altrootmnt = mntget(old->altrootmnt);
586 fs->altroot = dget(old->altroot);
588 fs->altrootmnt = NULL;
591 read_unlock(&old->lock);
596 struct fs_struct *copy_fs_struct(struct fs_struct *old)
598 return __copy_fs_struct(old);
601 EXPORT_SYMBOL_GPL(copy_fs_struct);
603 static inline int copy_fs(unsigned long clone_flags, struct task_struct * tsk)
605 if (clone_flags & CLONE_FS) {
606 atomic_inc(¤t->fs->count);
609 tsk->fs = __copy_fs_struct(current->fs);
615 static int count_open_files(struct fdtable *fdt)
617 int size = fdt->max_fds;
620 /* Find the last open fd */
621 for (i = size/(8*sizeof(long)); i > 0; ) {
622 if (fdt->open_fds->fds_bits[--i])
625 i = (i+1) * 8 * sizeof(long);
629 static struct files_struct *alloc_files(void)
631 struct files_struct *newf;
634 newf = kmem_cache_alloc(files_cachep, GFP_KERNEL);
638 atomic_set(&newf->count, 1);
640 spin_lock_init(&newf->file_lock);
643 fdt->max_fds = NR_OPEN_DEFAULT;
644 fdt->close_on_exec = (fd_set *)&newf->close_on_exec_init;
645 fdt->open_fds = (fd_set *)&newf->open_fds_init;
646 fdt->fd = &newf->fd_array[0];
647 INIT_RCU_HEAD(&fdt->rcu);
648 fdt->free_files = NULL;
650 rcu_assign_pointer(newf->fdt, fdt);
656 * Allocate a new files structure and copy contents from the
657 * passed in files structure.
658 * errorp will be valid only when the returned files_struct is NULL.
660 static struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)
662 struct files_struct *newf;
663 struct file **old_fds, **new_fds;
664 int open_files, size, i;
665 struct fdtable *old_fdt, *new_fdt;
668 newf = alloc_files();
672 spin_lock(&oldf->file_lock);
673 old_fdt = files_fdtable(oldf);
674 new_fdt = files_fdtable(newf);
675 open_files = count_open_files(old_fdt);
678 * Check whether we need to allocate a larger fd array and fd set.
679 * Note: we're not a clone task, so the open count won't change.
681 if (open_files > new_fdt->max_fds) {
682 new_fdt->max_fds = 0;
683 spin_unlock(&oldf->file_lock);
684 spin_lock(&newf->file_lock);
685 *errorp = expand_files(newf, open_files-1);
686 spin_unlock(&newf->file_lock);
689 new_fdt = files_fdtable(newf);
691 * Reacquire the oldf lock and a pointer to its fd table
692 * who knows it may have a new bigger fd table. We need
693 * the latest pointer.
695 spin_lock(&oldf->file_lock);
696 old_fdt = files_fdtable(oldf);
699 old_fds = old_fdt->fd;
700 new_fds = new_fdt->fd;
702 memcpy(new_fdt->open_fds->fds_bits,
703 old_fdt->open_fds->fds_bits, open_files/8);
704 memcpy(new_fdt->close_on_exec->fds_bits,
705 old_fdt->close_on_exec->fds_bits, open_files/8);
707 for (i = open_files; i != 0; i--) {
708 struct file *f = *old_fds++;
713 * The fd may be claimed in the fd bitmap but not yet
714 * instantiated in the files array if a sibling thread
715 * is partway through open(). So make sure that this
716 * fd is available to the new process.
718 FD_CLR(open_files - i, new_fdt->open_fds);
720 rcu_assign_pointer(*new_fds++, f);
722 spin_unlock(&oldf->file_lock);
724 /* compute the remainder to be cleared */
725 size = (new_fdt->max_fds - open_files) * sizeof(struct file *);
727 /* This is long word aligned thus could use a optimized version */
728 memset(new_fds, 0, size);
730 if (new_fdt->max_fds > open_files) {
731 int left = (new_fdt->max_fds-open_files)/8;
732 int start = open_files / (8 * sizeof(unsigned long));
734 memset(&new_fdt->open_fds->fds_bits[start], 0, left);
735 memset(&new_fdt->close_on_exec->fds_bits[start], 0, left);
741 kmem_cache_free(files_cachep, newf);
746 static int copy_files(unsigned long clone_flags, struct task_struct * tsk)
748 struct files_struct *oldf, *newf;
752 * A background process may not have any files ...
754 oldf = current->files;
758 if (clone_flags & CLONE_FILES) {
759 atomic_inc(&oldf->count);
764 * Note: we may be using current for both targets (See exec.c)
765 * This works because we cache current->files (old) as oldf. Don't
769 newf = dup_fd(oldf, &error);
780 * Helper to unshare the files of the current task.
781 * We don't want to expose copy_files internals to
782 * the exec layer of the kernel.
785 int unshare_files(void)
787 struct files_struct *files = current->files;
792 /* This can race but the race causes us to copy when we don't
793 need to and drop the copy */
794 if(atomic_read(&files->count) == 1)
796 atomic_inc(&files->count);
799 rc = copy_files(0, current);
801 current->files = files;
805 EXPORT_SYMBOL(unshare_files);
807 static inline int copy_sighand(unsigned long clone_flags, struct task_struct * tsk)
809 struct sighand_struct *sig;
811 if (clone_flags & (CLONE_SIGHAND | CLONE_THREAD)) {
812 atomic_inc(¤t->sighand->count);
815 sig = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
816 rcu_assign_pointer(tsk->sighand, sig);
819 atomic_set(&sig->count, 1);
820 memcpy(sig->action, current->sighand->action, sizeof(sig->action));
824 void __cleanup_sighand(struct sighand_struct *sighand)
826 if (atomic_dec_and_test(&sighand->count))
827 kmem_cache_free(sighand_cachep, sighand);
830 static inline int copy_signal(unsigned long clone_flags, struct task_struct * tsk)
832 struct signal_struct *sig;
835 if (clone_flags & CLONE_THREAD) {
836 atomic_inc(¤t->signal->count);
837 atomic_inc(¤t->signal->live);
840 sig = kmem_cache_alloc(signal_cachep, GFP_KERNEL);
845 ret = copy_thread_group_keys(tsk);
847 kmem_cache_free(signal_cachep, sig);
851 atomic_set(&sig->count, 1);
852 atomic_set(&sig->live, 1);
853 init_waitqueue_head(&sig->wait_chldexit);
855 sig->group_exit_code = 0;
856 sig->group_exit_task = NULL;
857 sig->group_stop_count = 0;
858 sig->curr_target = NULL;
859 init_sigpending(&sig->shared_pending);
860 INIT_LIST_HEAD(&sig->posix_timers);
862 hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_REL);
863 sig->it_real_incr.tv64 = 0;
864 sig->real_timer.function = it_real_fn;
867 sig->it_virt_expires = cputime_zero;
868 sig->it_virt_incr = cputime_zero;
869 sig->it_prof_expires = cputime_zero;
870 sig->it_prof_incr = cputime_zero;
872 sig->leader = 0; /* session leadership doesn't inherit */
873 sig->tty_old_pgrp = 0;
875 sig->utime = sig->stime = sig->cutime = sig->cstime = cputime_zero;
876 sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
877 sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
879 INIT_LIST_HEAD(&sig->cpu_timers[0]);
880 INIT_LIST_HEAD(&sig->cpu_timers[1]);
881 INIT_LIST_HEAD(&sig->cpu_timers[2]);
882 taskstats_tgid_init(sig);
884 task_lock(current->group_leader);
885 memcpy(sig->rlim, current->signal->rlim, sizeof sig->rlim);
886 task_unlock(current->group_leader);
888 if (sig->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
890 * New sole thread in the process gets an expiry time
891 * of the whole CPU time limit.
893 tsk->it_prof_expires =
894 secs_to_cputime(sig->rlim[RLIMIT_CPU].rlim_cur);
896 acct_init_pacct(&sig->pacct);
901 void __cleanup_signal(struct signal_struct *sig)
903 exit_thread_group_keys(sig);
904 kmem_cache_free(signal_cachep, sig);
907 static inline void cleanup_signal(struct task_struct *tsk)
909 struct signal_struct *sig = tsk->signal;
911 atomic_dec(&sig->live);
913 if (atomic_dec_and_test(&sig->count))
914 __cleanup_signal(sig);
917 static inline void copy_flags(unsigned long clone_flags, struct task_struct *p)
919 unsigned long new_flags = p->flags;
921 new_flags &= ~(PF_SUPERPRIV | PF_NOFREEZE);
922 new_flags |= PF_FORKNOEXEC;
923 if (!(clone_flags & CLONE_PTRACE))
925 p->flags = new_flags;
928 asmlinkage long sys_set_tid_address(int __user *tidptr)
930 current->clear_child_tid = tidptr;
935 static inline void rt_mutex_init_task(struct task_struct *p)
937 #ifdef CONFIG_RT_MUTEXES
938 spin_lock_init(&p->pi_lock);
939 plist_head_init(&p->pi_waiters, &p->pi_lock);
940 p->pi_blocked_on = NULL;
945 * This creates a new process as a copy of the old one,
946 * but does not actually start it yet.
948 * It copies the registers, and all the appropriate
949 * parts of the process environment (as per the clone
950 * flags). The actual kick-off is left to the caller.
952 static struct task_struct *copy_process(unsigned long clone_flags,
953 unsigned long stack_start,
954 struct pt_regs *regs,
955 unsigned long stack_size,
956 int __user *parent_tidptr,
957 int __user *child_tidptr,
961 struct task_struct *p = NULL;
963 if ((clone_flags & (CLONE_NEWNS|CLONE_FS)) == (CLONE_NEWNS|CLONE_FS))
964 return ERR_PTR(-EINVAL);
967 * Thread groups must share signals as well, and detached threads
968 * can only be started up within the thread group.
970 if ((clone_flags & CLONE_THREAD) && !(clone_flags & CLONE_SIGHAND))
971 return ERR_PTR(-EINVAL);
974 * Shared signal handlers imply shared VM. By way of the above,
975 * thread groups also imply shared VM. Blocking this case allows
976 * for various simplifications in other code.
978 if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM))
979 return ERR_PTR(-EINVAL);
981 retval = security_task_create(clone_flags);
986 p = dup_task_struct(current);
990 rt_mutex_init_task(p);
992 #ifdef CONFIG_TRACE_IRQFLAGS
993 DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
994 DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
997 if (atomic_read(&p->user->processes) >=
998 p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
999 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
1000 p->user != &root_user)
1004 atomic_inc(&p->user->__count);
1005 atomic_inc(&p->user->processes);
1006 get_group_info(p->group_info);
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.
1013 if (nr_threads >= max_threads)
1014 goto bad_fork_cleanup_count;
1016 if (!try_module_get(task_thread_info(p)->exec_domain->module))
1017 goto bad_fork_cleanup_count;
1019 if (p->binfmt && !try_module_get(p->binfmt->module))
1020 goto bad_fork_cleanup_put_domain;
1023 delayacct_tsk_init(p); /* Must remain after dup_task_struct() */
1024 copy_flags(clone_flags, p);
1027 if (clone_flags & CLONE_PARENT_SETTID)
1028 if (put_user(p->pid, parent_tidptr))
1029 goto bad_fork_cleanup_delays_binfmt;
1031 INIT_LIST_HEAD(&p->children);
1032 INIT_LIST_HEAD(&p->sibling);
1033 p->vfork_done = NULL;
1034 spin_lock_init(&p->alloc_lock);
1036 clear_tsk_thread_flag(p, TIF_SIGPENDING);
1037 init_sigpending(&p->pending);
1039 p->utime = cputime_zero;
1040 p->stime = cputime_zero;
1042 p->rchar = 0; /* I/O counter: bytes read */
1043 p->wchar = 0; /* I/O counter: bytes written */
1044 p->syscr = 0; /* I/O counter: read syscalls */
1045 p->syscw = 0; /* I/O counter: write syscalls */
1046 task_io_accounting_init(p);
1047 acct_clear_integrals(p);
1049 p->it_virt_expires = cputime_zero;
1050 p->it_prof_expires = cputime_zero;
1051 p->it_sched_expires = 0;
1052 INIT_LIST_HEAD(&p->cpu_timers[0]);
1053 INIT_LIST_HEAD(&p->cpu_timers[1]);
1054 INIT_LIST_HEAD(&p->cpu_timers[2]);
1056 p->lock_depth = -1; /* -1 = no lock */
1057 do_posix_clock_monotonic_gettime(&p->start_time);
1059 p->io_context = NULL;
1061 p->audit_context = NULL;
1064 p->mempolicy = mpol_copy(p->mempolicy);
1065 if (IS_ERR(p->mempolicy)) {
1066 retval = PTR_ERR(p->mempolicy);
1067 p->mempolicy = NULL;
1068 goto bad_fork_cleanup_cpuset;
1070 mpol_fix_fork_child_flag(p);
1072 #ifdef CONFIG_TRACE_IRQFLAGS
1074 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
1075 p->hardirqs_enabled = 1;
1077 p->hardirqs_enabled = 0;
1079 p->hardirq_enable_ip = 0;
1080 p->hardirq_enable_event = 0;
1081 p->hardirq_disable_ip = _THIS_IP_;
1082 p->hardirq_disable_event = 0;
1083 p->softirqs_enabled = 1;
1084 p->softirq_enable_ip = _THIS_IP_;
1085 p->softirq_enable_event = 0;
1086 p->softirq_disable_ip = 0;
1087 p->softirq_disable_event = 0;
1088 p->hardirq_context = 0;
1089 p->softirq_context = 0;
1091 #ifdef CONFIG_LOCKDEP
1092 p->lockdep_depth = 0; /* no locks held yet */
1093 p->curr_chain_key = 0;
1094 p->lockdep_recursion = 0;
1097 #ifdef CONFIG_DEBUG_MUTEXES
1098 p->blocked_on = NULL; /* not blocked yet */
1102 if (clone_flags & CLONE_THREAD)
1103 p->tgid = current->tgid;
1105 if ((retval = security_task_alloc(p)))
1106 goto bad_fork_cleanup_policy;
1107 if ((retval = audit_alloc(p)))
1108 goto bad_fork_cleanup_security;
1109 /* copy all the process information */
1110 if ((retval = copy_semundo(clone_flags, p)))
1111 goto bad_fork_cleanup_audit;
1112 if ((retval = copy_files(clone_flags, p)))
1113 goto bad_fork_cleanup_semundo;
1114 if ((retval = copy_fs(clone_flags, p)))
1115 goto bad_fork_cleanup_files;
1116 if ((retval = copy_sighand(clone_flags, p)))
1117 goto bad_fork_cleanup_fs;
1118 if ((retval = copy_signal(clone_flags, p)))
1119 goto bad_fork_cleanup_sighand;
1120 if ((retval = copy_mm(clone_flags, p)))
1121 goto bad_fork_cleanup_signal;
1122 if ((retval = copy_keys(clone_flags, p)))
1123 goto bad_fork_cleanup_mm;
1124 if ((retval = copy_namespaces(clone_flags, p)))
1125 goto bad_fork_cleanup_keys;
1126 retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
1128 goto bad_fork_cleanup_namespaces;
1130 p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
1132 * Clear TID on mm_release()?
1134 p->clear_child_tid = (clone_flags & CLONE_CHILD_CLEARTID) ? child_tidptr: NULL;
1135 p->robust_list = NULL;
1136 #ifdef CONFIG_COMPAT
1137 p->compat_robust_list = NULL;
1139 INIT_LIST_HEAD(&p->pi_state_list);
1140 p->pi_state_cache = NULL;
1143 * sigaltstack should be cleared when sharing the same VM
1145 if ((clone_flags & (CLONE_VM|CLONE_VFORK)) == CLONE_VM)
1146 p->sas_ss_sp = p->sas_ss_size = 0;
1149 * Syscall tracing should be turned off in the child regardless
1152 clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
1153 #ifdef TIF_SYSCALL_EMU
1154 clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
1157 /* Our parent execution domain becomes current domain
1158 These must match for thread signalling to apply */
1159 p->parent_exec_id = p->self_exec_id;
1161 /* ok, now we should be set up.. */
1162 p->exit_signal = (clone_flags & CLONE_THREAD) ? -1 : (clone_flags & CSIGNAL);
1163 p->pdeath_signal = 0;
1167 * Ok, make it visible to the rest of the system.
1168 * We dont wake it up yet.
1170 p->group_leader = p;
1171 INIT_LIST_HEAD(&p->thread_group);
1172 INIT_LIST_HEAD(&p->ptrace_children);
1173 INIT_LIST_HEAD(&p->ptrace_list);
1175 /* Perform scheduler related setup. Assign this task to a CPU. */
1176 sched_fork(p, clone_flags);
1178 /* Need tasklist lock for parent etc handling! */
1179 write_lock_irq(&tasklist_lock);
1181 /* for sys_ioprio_set(IOPRIO_WHO_PGRP) */
1182 p->ioprio = current->ioprio;
1185 * The task hasn't been attached yet, so its cpus_allowed mask will
1186 * not be changed, nor will its assigned CPU.
1188 * The cpus_allowed mask of the parent may have changed after it was
1189 * copied first time - so re-copy it here, then check the child's CPU
1190 * to ensure it is on a valid CPU (and if not, just force it back to
1191 * parent's CPU). This avoids alot of nasty races.
1193 p->cpus_allowed = current->cpus_allowed;
1194 if (unlikely(!cpu_isset(task_cpu(p), p->cpus_allowed) ||
1195 !cpu_online(task_cpu(p))))
1196 set_task_cpu(p, smp_processor_id());
1198 /* CLONE_PARENT re-uses the old parent */
1199 if (clone_flags & (CLONE_PARENT|CLONE_THREAD))
1200 p->real_parent = current->real_parent;
1202 p->real_parent = current;
1203 p->parent = p->real_parent;
1205 spin_lock(¤t->sighand->siglock);
1208 * Process group and session signals need to be delivered to just the
1209 * parent before the fork or both the parent and the child after the
1210 * fork. Restart if a signal comes in before we add the new process to
1211 * it's process group.
1212 * A fatal signal pending means that current will exit, so the new
1213 * thread can't slip out of an OOM kill (or normal SIGKILL).
1215 recalc_sigpending();
1216 if (signal_pending(current)) {
1217 spin_unlock(¤t->sighand->siglock);
1218 write_unlock_irq(&tasklist_lock);
1219 retval = -ERESTARTNOINTR;
1220 goto bad_fork_cleanup_namespaces;
1223 if (clone_flags & CLONE_THREAD) {
1224 p->group_leader = current->group_leader;
1225 list_add_tail_rcu(&p->thread_group, &p->group_leader->thread_group);
1227 if (!cputime_eq(current->signal->it_virt_expires,
1229 !cputime_eq(current->signal->it_prof_expires,
1231 current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY ||
1232 !list_empty(¤t->signal->cpu_timers[0]) ||
1233 !list_empty(¤t->signal->cpu_timers[1]) ||
1234 !list_empty(¤t->signal->cpu_timers[2])) {
1236 * Have child wake up on its first tick to check
1237 * for process CPU timers.
1239 p->it_prof_expires = jiffies_to_cputime(1);
1243 if (likely(p->pid)) {
1245 if (unlikely(p->ptrace & PT_PTRACED))
1246 __ptrace_link(p, current->parent);
1248 if (thread_group_leader(p)) {
1249 p->signal->tty = current->signal->tty;
1250 p->signal->pgrp = process_group(current);
1251 set_signal_session(p->signal, process_session(current));
1252 attach_pid(p, PIDTYPE_PGID, process_group(p));
1253 attach_pid(p, PIDTYPE_SID, process_session(p));
1255 list_add_tail_rcu(&p->tasks, &init_task.tasks);
1256 __get_cpu_var(process_counts)++;
1258 attach_pid(p, PIDTYPE_PID, p->pid);
1263 spin_unlock(¤t->sighand->siglock);
1264 write_unlock_irq(&tasklist_lock);
1265 proc_fork_connector(p);
1268 bad_fork_cleanup_namespaces:
1269 exit_task_namespaces(p);
1270 bad_fork_cleanup_keys:
1272 bad_fork_cleanup_mm:
1275 bad_fork_cleanup_signal:
1277 bad_fork_cleanup_sighand:
1278 __cleanup_sighand(p->sighand);
1279 bad_fork_cleanup_fs:
1280 exit_fs(p); /* blocking */
1281 bad_fork_cleanup_files:
1282 exit_files(p); /* blocking */
1283 bad_fork_cleanup_semundo:
1285 bad_fork_cleanup_audit:
1287 bad_fork_cleanup_security:
1288 security_task_free(p);
1289 bad_fork_cleanup_policy:
1291 mpol_free(p->mempolicy);
1292 bad_fork_cleanup_cpuset:
1295 bad_fork_cleanup_delays_binfmt:
1296 delayacct_tsk_free(p);
1298 module_put(p->binfmt->module);
1299 bad_fork_cleanup_put_domain:
1300 module_put(task_thread_info(p)->exec_domain->module);
1301 bad_fork_cleanup_count:
1302 put_group_info(p->group_info);
1303 atomic_dec(&p->user->processes);
1308 return ERR_PTR(retval);
1311 noinline struct pt_regs * __devinit __attribute__((weak)) idle_regs(struct pt_regs *regs)
1313 memset(regs, 0, sizeof(struct pt_regs));
1317 struct task_struct * __devinit fork_idle(int cpu)
1319 struct task_struct *task;
1320 struct pt_regs regs;
1322 task = copy_process(CLONE_VM, 0, idle_regs(®s), 0, NULL, NULL, 0);
1324 init_idle(task, cpu);
1329 static inline int fork_traceflag (unsigned clone_flags)
1331 if (clone_flags & CLONE_UNTRACED)
1333 else if (clone_flags & CLONE_VFORK) {
1334 if (current->ptrace & PT_TRACE_VFORK)
1335 return PTRACE_EVENT_VFORK;
1336 } else if ((clone_flags & CSIGNAL) != SIGCHLD) {
1337 if (current->ptrace & PT_TRACE_CLONE)
1338 return PTRACE_EVENT_CLONE;
1339 } else if (current->ptrace & PT_TRACE_FORK)
1340 return PTRACE_EVENT_FORK;
1346 * Ok, this is the main fork-routine.
1348 * It copies the process, and if successful kick-starts
1349 * it and waits for it to finish using the VM if required.
1351 long do_fork(unsigned long clone_flags,
1352 unsigned long stack_start,
1353 struct pt_regs *regs,
1354 unsigned long stack_size,
1355 int __user *parent_tidptr,
1356 int __user *child_tidptr)
1358 struct task_struct *p;
1360 struct pid *pid = alloc_pid();
1366 if (unlikely(current->ptrace)) {
1367 trace = fork_traceflag (clone_flags);
1369 clone_flags |= CLONE_PTRACE;
1372 p = copy_process(clone_flags, stack_start, regs, stack_size, parent_tidptr, child_tidptr, nr);
1374 * Do this prior waking up the new thread - the thread pointer
1375 * might get invalid after that point, if the thread exits quickly.
1378 struct completion vfork;
1380 if (clone_flags & CLONE_VFORK) {
1381 p->vfork_done = &vfork;
1382 init_completion(&vfork);
1385 if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) {
1387 * We'll start up with an immediate SIGSTOP.
1389 sigaddset(&p->pending.signal, SIGSTOP);
1390 set_tsk_thread_flag(p, TIF_SIGPENDING);
1393 if (!(clone_flags & CLONE_STOPPED))
1394 wake_up_new_task(p, clone_flags);
1396 p->state = TASK_STOPPED;
1398 if (unlikely (trace)) {
1399 current->ptrace_message = nr;
1400 ptrace_notify ((trace << 8) | SIGTRAP);
1403 if (clone_flags & CLONE_VFORK) {
1404 wait_for_completion(&vfork);
1405 if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE)) {
1406 current->ptrace_message = nr;
1407 ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
1417 #ifndef ARCH_MIN_MMSTRUCT_ALIGN
1418 #define ARCH_MIN_MMSTRUCT_ALIGN 0
1421 static void sighand_ctor(void *data, struct kmem_cache *cachep, unsigned long flags)
1423 struct sighand_struct *sighand = data;
1425 if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) ==
1426 SLAB_CTOR_CONSTRUCTOR)
1427 spin_lock_init(&sighand->siglock);
1430 void __init proc_caches_init(void)
1432 sighand_cachep = kmem_cache_create("sighand_cache",
1433 sizeof(struct sighand_struct), 0,
1434 SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_DESTROY_BY_RCU,
1435 sighand_ctor, NULL);
1436 signal_cachep = kmem_cache_create("signal_cache",
1437 sizeof(struct signal_struct), 0,
1438 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1439 files_cachep = kmem_cache_create("files_cache",
1440 sizeof(struct files_struct), 0,
1441 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1442 fs_cachep = kmem_cache_create("fs_cache",
1443 sizeof(struct fs_struct), 0,
1444 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1445 vm_area_cachep = kmem_cache_create("vm_area_struct",
1446 sizeof(struct vm_area_struct), 0,
1447 SLAB_PANIC, NULL, NULL);
1448 mm_cachep = kmem_cache_create("mm_struct",
1449 sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
1450 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);
1455 * Check constraints on flags passed to the unshare system call and
1456 * force unsharing of additional process context as appropriate.
1458 static inline void check_unshare_flags(unsigned long *flags_ptr)
1461 * If unsharing a thread from a thread group, must also
1464 if (*flags_ptr & CLONE_THREAD)
1465 *flags_ptr |= CLONE_VM;
1468 * If unsharing vm, must also unshare signal handlers.
1470 if (*flags_ptr & CLONE_VM)
1471 *flags_ptr |= CLONE_SIGHAND;
1474 * If unsharing signal handlers and the task was created
1475 * using CLONE_THREAD, then must unshare the thread
1477 if ((*flags_ptr & CLONE_SIGHAND) &&
1478 (atomic_read(¤t->signal->count) > 1))
1479 *flags_ptr |= CLONE_THREAD;
1482 * If unsharing namespace, must also unshare filesystem information.
1484 if (*flags_ptr & CLONE_NEWNS)
1485 *flags_ptr |= CLONE_FS;
1489 * Unsharing of tasks created with CLONE_THREAD is not supported yet
1491 static int unshare_thread(unsigned long unshare_flags)
1493 if (unshare_flags & CLONE_THREAD)
1500 * Unshare the filesystem structure if it is being shared
1502 static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp)
1504 struct fs_struct *fs = current->fs;
1506 if ((unshare_flags & CLONE_FS) &&
1507 (fs && atomic_read(&fs->count) > 1)) {
1508 *new_fsp = __copy_fs_struct(current->fs);
1517 * Unshare the mnt_namespace structure if it is being shared
1519 static int unshare_mnt_namespace(unsigned long unshare_flags,
1520 struct mnt_namespace **new_nsp, struct fs_struct *new_fs)
1522 struct mnt_namespace *ns = current->nsproxy->mnt_ns;
1524 if ((unshare_flags & CLONE_NEWNS) && ns) {
1525 if (!capable(CAP_SYS_ADMIN))
1528 *new_nsp = dup_mnt_ns(current, new_fs ? new_fs : current->fs);
1537 * Unsharing of sighand is not supported yet
1539 static int unshare_sighand(unsigned long unshare_flags, struct sighand_struct **new_sighp)
1541 struct sighand_struct *sigh = current->sighand;
1543 if ((unshare_flags & CLONE_SIGHAND) && atomic_read(&sigh->count) > 1)
1550 * Unshare vm if it is being shared
1552 static int unshare_vm(unsigned long unshare_flags, struct mm_struct **new_mmp)
1554 struct mm_struct *mm = current->mm;
1556 if ((unshare_flags & CLONE_VM) &&
1557 (mm && atomic_read(&mm->mm_users) > 1)) {
1565 * Unshare file descriptor table if it is being shared
1567 static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp)
1569 struct files_struct *fd = current->files;
1572 if ((unshare_flags & CLONE_FILES) &&
1573 (fd && atomic_read(&fd->count) > 1)) {
1574 *new_fdp = dup_fd(fd, &error);
1583 * Unsharing of semundo for tasks created with CLONE_SYSVSEM is not
1586 static int unshare_semundo(unsigned long unshare_flags, struct sem_undo_list **new_ulistp)
1588 if (unshare_flags & CLONE_SYSVSEM)
1594 #ifndef CONFIG_IPC_NS
1595 static inline int unshare_ipcs(unsigned long flags, struct ipc_namespace **ns)
1597 if (flags & CLONE_NEWIPC)
1605 * unshare allows a process to 'unshare' part of the process
1606 * context which was originally shared using clone. copy_*
1607 * functions used by do_fork() cannot be used here directly
1608 * because they modify an inactive task_struct that is being
1609 * constructed. Here we are modifying the current, active,
1612 asmlinkage long sys_unshare(unsigned long unshare_flags)
1615 struct fs_struct *fs, *new_fs = NULL;
1616 struct mnt_namespace *ns, *new_ns = NULL;
1617 struct sighand_struct *new_sigh = NULL;
1618 struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL;
1619 struct files_struct *fd, *new_fd = NULL;
1620 struct sem_undo_list *new_ulist = NULL;
1621 struct nsproxy *new_nsproxy = NULL, *old_nsproxy = NULL;
1622 struct uts_namespace *uts, *new_uts = NULL;
1623 struct ipc_namespace *ipc, *new_ipc = NULL;
1625 check_unshare_flags(&unshare_flags);
1627 /* Return -EINVAL for all unsupported flags */
1629 if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
1630 CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
1631 CLONE_NEWUTS|CLONE_NEWIPC))
1632 goto bad_unshare_out;
1634 if ((err = unshare_thread(unshare_flags)))
1635 goto bad_unshare_out;
1636 if ((err = unshare_fs(unshare_flags, &new_fs)))
1637 goto bad_unshare_cleanup_thread;
1638 if ((err = unshare_mnt_namespace(unshare_flags, &new_ns, new_fs)))
1639 goto bad_unshare_cleanup_fs;
1640 if ((err = unshare_sighand(unshare_flags, &new_sigh)))
1641 goto bad_unshare_cleanup_ns;
1642 if ((err = unshare_vm(unshare_flags, &new_mm)))
1643 goto bad_unshare_cleanup_sigh;
1644 if ((err = unshare_fd(unshare_flags, &new_fd)))
1645 goto bad_unshare_cleanup_vm;
1646 if ((err = unshare_semundo(unshare_flags, &new_ulist)))
1647 goto bad_unshare_cleanup_fd;
1648 if ((err = unshare_utsname(unshare_flags, &new_uts)))
1649 goto bad_unshare_cleanup_semundo;
1650 if ((err = unshare_ipcs(unshare_flags, &new_ipc)))
1651 goto bad_unshare_cleanup_uts;
1653 if (new_ns || new_uts || new_ipc) {
1654 old_nsproxy = current->nsproxy;
1655 new_nsproxy = dup_namespaces(old_nsproxy);
1658 goto bad_unshare_cleanup_ipc;
1662 if (new_fs || new_ns || new_mm || new_fd || new_ulist ||
1663 new_uts || new_ipc) {
1668 current->nsproxy = new_nsproxy;
1669 new_nsproxy = old_nsproxy;
1674 current->fs = new_fs;
1679 ns = current->nsproxy->mnt_ns;
1680 current->nsproxy->mnt_ns = new_ns;
1686 active_mm = current->active_mm;
1687 current->mm = new_mm;
1688 current->active_mm = new_mm;
1689 activate_mm(active_mm, new_mm);
1694 fd = current->files;
1695 current->files = new_fd;
1700 uts = current->nsproxy->uts_ns;
1701 current->nsproxy->uts_ns = new_uts;
1706 ipc = current->nsproxy->ipc_ns;
1707 current->nsproxy->ipc_ns = new_ipc;
1711 task_unlock(current);
1715 put_nsproxy(new_nsproxy);
1717 bad_unshare_cleanup_ipc:
1719 put_ipc_ns(new_ipc);
1721 bad_unshare_cleanup_uts:
1723 put_uts_ns(new_uts);
1725 bad_unshare_cleanup_semundo:
1726 bad_unshare_cleanup_fd:
1728 put_files_struct(new_fd);
1730 bad_unshare_cleanup_vm:
1734 bad_unshare_cleanup_sigh:
1736 if (atomic_dec_and_test(&new_sigh->count))
1737 kmem_cache_free(sighand_cachep, new_sigh);
1739 bad_unshare_cleanup_ns:
1743 bad_unshare_cleanup_fs:
1745 put_fs_struct(new_fs);
1747 bad_unshare_cleanup_thread: