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/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/capability.h>
31 #include <linux/cpu.h>
32 #include <linux/cpuset.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/rcupdate.h>
39 #include <linux/ptrace.h>
40 #include <linux/mount.h>
41 #include <linux/audit.h>
42 #include <linux/profile.h>
43 #include <linux/rmap.h>
44 #include <linux/acct.h>
45 #include <linux/cn_proc.h>
46 #include <linux/delayacct.h>
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>
56 * Protected counters by write_lock_irq(&tasklist_lock)
58 unsigned long total_forks
; /* Handle normal Linux uptimes. */
59 int nr_threads
; /* The idle threads do not count.. */
61 int max_threads
; /* tunable limit on nr_threads */
63 DEFINE_PER_CPU(unsigned long, process_counts
) = 0;
65 __cacheline_aligned
DEFINE_RWLOCK(tasklist_lock
); /* outer */
67 int nr_processes(void)
72 for_each_online_cpu(cpu
)
73 total
+= per_cpu(process_counts
, cpu
);
78 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
79 # define alloc_task_struct() kmem_cache_alloc(task_struct_cachep, GFP_KERNEL)
80 # define free_task_struct(tsk) kmem_cache_free(task_struct_cachep, (tsk))
81 static kmem_cache_t
*task_struct_cachep
;
84 /* SLAB cache for signal_struct structures (tsk->signal) */
85 static kmem_cache_t
*signal_cachep
;
87 /* SLAB cache for sighand_struct structures (tsk->sighand) */
88 kmem_cache_t
*sighand_cachep
;
90 /* SLAB cache for files_struct structures (tsk->files) */
91 kmem_cache_t
*files_cachep
;
93 /* SLAB cache for fs_struct structures (tsk->fs) */
94 kmem_cache_t
*fs_cachep
;
96 /* SLAB cache for vm_area_struct structures */
97 kmem_cache_t
*vm_area_cachep
;
99 /* SLAB cache for mm_struct structures (tsk->mm) */
100 static kmem_cache_t
*mm_cachep
;
102 void free_task(struct task_struct
*tsk
)
104 free_thread_info(tsk
->thread_info
);
105 rt_mutex_debug_task_free(tsk
);
106 free_task_struct(tsk
);
108 EXPORT_SYMBOL(free_task
);
110 void __put_task_struct(struct task_struct
*tsk
)
112 WARN_ON(!(tsk
->exit_state
& (EXIT_DEAD
| EXIT_ZOMBIE
)));
113 WARN_ON(atomic_read(&tsk
->usage
));
114 WARN_ON(tsk
== current
);
116 security_task_free(tsk
);
118 put_group_info(tsk
->group_info
);
120 if (!profile_handoff_task(tsk
))
124 void __init
fork_init(unsigned long mempages
)
126 #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR
127 #ifndef ARCH_MIN_TASKALIGN
128 #define ARCH_MIN_TASKALIGN L1_CACHE_BYTES
130 /* create a slab on which task_structs can be allocated */
132 kmem_cache_create("task_struct", sizeof(struct task_struct
),
133 ARCH_MIN_TASKALIGN
, SLAB_PANIC
, NULL
, NULL
);
137 * The default maximum number of threads is set to a safe
138 * value: the thread structures can take up at most half
141 max_threads
= mempages
/ (8 * THREAD_SIZE
/ PAGE_SIZE
);
144 * we need to allow at least 20 threads to boot a system
149 init_task
.signal
->rlim
[RLIMIT_NPROC
].rlim_cur
= max_threads
/2;
150 init_task
.signal
->rlim
[RLIMIT_NPROC
].rlim_max
= max_threads
/2;
151 init_task
.signal
->rlim
[RLIMIT_SIGPENDING
] =
152 init_task
.signal
->rlim
[RLIMIT_NPROC
];
155 static struct task_struct
*dup_task_struct(struct task_struct
*orig
)
157 struct task_struct
*tsk
;
158 struct thread_info
*ti
;
160 prepare_to_copy(orig
);
162 tsk
= alloc_task_struct();
166 ti
= alloc_thread_info(tsk
);
168 free_task_struct(tsk
);
173 tsk
->thread_info
= ti
;
174 setup_thread_stack(tsk
, orig
);
176 /* One for us, one for whoever does the "release_task()" (usually parent) */
177 atomic_set(&tsk
->usage
,2);
178 atomic_set(&tsk
->fs_excl
, 0);
180 tsk
->splice_pipe
= NULL
;
185 static inline int dup_mmap(struct mm_struct
*mm
, struct mm_struct
*oldmm
)
187 struct vm_area_struct
*mpnt
, *tmp
, **pprev
;
188 struct rb_node
**rb_link
, *rb_parent
;
190 unsigned long charge
;
191 struct mempolicy
*pol
;
193 down_write(&oldmm
->mmap_sem
);
194 flush_cache_mm(oldmm
);
196 * Not linked in yet - no deadlock potential:
198 down_write_nested(&mm
->mmap_sem
, SINGLE_DEPTH_NESTING
);
202 mm
->mmap_cache
= NULL
;
203 mm
->free_area_cache
= oldmm
->mmap_base
;
204 mm
->cached_hole_size
= ~0UL;
206 cpus_clear(mm
->cpu_vm_mask
);
208 rb_link
= &mm
->mm_rb
.rb_node
;
212 for (mpnt
= oldmm
->mmap
; mpnt
; mpnt
= mpnt
->vm_next
) {
215 if (mpnt
->vm_flags
& VM_DONTCOPY
) {
216 long pages
= vma_pages(mpnt
);
217 mm
->total_vm
-= pages
;
218 vm_stat_account(mm
, mpnt
->vm_flags
, mpnt
->vm_file
,
223 if (mpnt
->vm_flags
& VM_ACCOUNT
) {
224 unsigned int len
= (mpnt
->vm_end
- mpnt
->vm_start
) >> PAGE_SHIFT
;
225 if (security_vm_enough_memory(len
))
229 tmp
= kmem_cache_alloc(vm_area_cachep
, SLAB_KERNEL
);
233 pol
= mpol_copy(vma_policy(mpnt
));
234 retval
= PTR_ERR(pol
);
236 goto fail_nomem_policy
;
237 vma_set_policy(tmp
, pol
);
238 tmp
->vm_flags
&= ~VM_LOCKED
;
244 struct inode
*inode
= file
->f_dentry
->d_inode
;
246 if (tmp
->vm_flags
& VM_DENYWRITE
)
247 atomic_dec(&inode
->i_writecount
);
249 /* insert tmp into the share list, just after mpnt */
250 spin_lock(&file
->f_mapping
->i_mmap_lock
);
251 tmp
->vm_truncate_count
= mpnt
->vm_truncate_count
;
252 flush_dcache_mmap_lock(file
->f_mapping
);
253 vma_prio_tree_add(tmp
, mpnt
);
254 flush_dcache_mmap_unlock(file
->f_mapping
);
255 spin_unlock(&file
->f_mapping
->i_mmap_lock
);
259 * Link in the new vma and copy the page table entries.
262 pprev
= &tmp
->vm_next
;
264 __vma_link_rb(mm
, tmp
, rb_link
, rb_parent
);
265 rb_link
= &tmp
->vm_rb
.rb_right
;
266 rb_parent
= &tmp
->vm_rb
;
269 retval
= copy_page_range(mm
, oldmm
, mpnt
);
271 if (tmp
->vm_ops
&& tmp
->vm_ops
->open
)
272 tmp
->vm_ops
->open(tmp
);
279 up_write(&mm
->mmap_sem
);
281 up_write(&oldmm
->mmap_sem
);
284 kmem_cache_free(vm_area_cachep
, tmp
);
287 vm_unacct_memory(charge
);
291 static inline int mm_alloc_pgd(struct mm_struct
* mm
)
293 mm
->pgd
= pgd_alloc(mm
);
294 if (unlikely(!mm
->pgd
))
299 static inline void mm_free_pgd(struct mm_struct
* mm
)
304 #define dup_mmap(mm, oldmm) (0)
305 #define mm_alloc_pgd(mm) (0)
306 #define mm_free_pgd(mm)
307 #endif /* CONFIG_MMU */
309 __cacheline_aligned_in_smp
DEFINE_SPINLOCK(mmlist_lock
);
311 #define allocate_mm() (kmem_cache_alloc(mm_cachep, SLAB_KERNEL))
312 #define free_mm(mm) (kmem_cache_free(mm_cachep, (mm)))
314 #include <linux/init_task.h>
316 static struct mm_struct
* mm_init(struct mm_struct
* mm
)
318 atomic_set(&mm
->mm_users
, 1);
319 atomic_set(&mm
->mm_count
, 1);
320 init_rwsem(&mm
->mmap_sem
);
321 INIT_LIST_HEAD(&mm
->mmlist
);
322 mm
->core_waiters
= 0;
324 set_mm_counter(mm
, file_rss
, 0);
325 set_mm_counter(mm
, anon_rss
, 0);
326 spin_lock_init(&mm
->page_table_lock
);
327 rwlock_init(&mm
->ioctx_list_lock
);
328 mm
->ioctx_list
= NULL
;
329 mm
->free_area_cache
= TASK_UNMAPPED_BASE
;
330 mm
->cached_hole_size
= ~0UL;
332 if (likely(!mm_alloc_pgd(mm
))) {
341 * Allocate and initialize an mm_struct.
343 struct mm_struct
* mm_alloc(void)
345 struct mm_struct
* mm
;
349 memset(mm
, 0, sizeof(*mm
));
356 * Called when the last reference to the mm
357 * is dropped: either by a lazy thread or by
358 * mmput. Free the page directory and the mm.
360 void fastcall
__mmdrop(struct mm_struct
*mm
)
362 BUG_ON(mm
== &init_mm
);
369 * Decrement the use count and release all resources for an mm.
371 void mmput(struct mm_struct
*mm
)
375 if (atomic_dec_and_test(&mm
->mm_users
)) {
378 if (!list_empty(&mm
->mmlist
)) {
379 spin_lock(&mmlist_lock
);
380 list_del(&mm
->mmlist
);
381 spin_unlock(&mmlist_lock
);
387 EXPORT_SYMBOL_GPL(mmput
);
390 * get_task_mm - acquire a reference to the task's mm
392 * Returns %NULL if the task has no mm. Checks PF_BORROWED_MM (meaning
393 * this kernel workthread has transiently adopted a user mm with use_mm,
394 * to do its AIO) is not set and if so returns a reference to it, after
395 * bumping up the use count. User must release the mm via mmput()
396 * after use. Typically used by /proc and ptrace.
398 struct mm_struct
*get_task_mm(struct task_struct
*task
)
400 struct mm_struct
*mm
;
405 if (task
->flags
& PF_BORROWED_MM
)
408 atomic_inc(&mm
->mm_users
);
413 EXPORT_SYMBOL_GPL(get_task_mm
);
415 /* Please note the differences between mmput and mm_release.
416 * mmput is called whenever we stop holding onto a mm_struct,
417 * error success whatever.
419 * mm_release is called after a mm_struct has been removed
420 * from the current process.
422 * This difference is important for error handling, when we
423 * only half set up a mm_struct for a new process and need to restore
424 * the old one. Because we mmput the new mm_struct before
425 * restoring the old one. . .
426 * Eric Biederman 10 January 1998
428 void mm_release(struct task_struct
*tsk
, struct mm_struct
*mm
)
430 struct completion
*vfork_done
= tsk
->vfork_done
;
432 /* Get rid of any cached register state */
433 deactivate_mm(tsk
, mm
);
435 /* notify parent sleeping on vfork() */
437 tsk
->vfork_done
= NULL
;
438 complete(vfork_done
);
440 if (tsk
->clear_child_tid
&& atomic_read(&mm
->mm_users
) > 1) {
441 u32 __user
* tidptr
= tsk
->clear_child_tid
;
442 tsk
->clear_child_tid
= NULL
;
445 * We don't check the error code - if userspace has
446 * not set up a proper pointer then tough luck.
449 sys_futex(tidptr
, FUTEX_WAKE
, 1, NULL
, NULL
, 0);
454 * Allocate a new mm structure and copy contents from the
455 * mm structure of the passed in task structure.
457 static struct mm_struct
*dup_mm(struct task_struct
*tsk
)
459 struct mm_struct
*mm
, *oldmm
= current
->mm
;
469 memcpy(mm
, oldmm
, sizeof(*mm
));
474 if (init_new_context(tsk
, mm
))
477 err
= dup_mmap(mm
, oldmm
);
481 mm
->hiwater_rss
= get_mm_rss(mm
);
482 mm
->hiwater_vm
= mm
->total_vm
;
494 * If init_new_context() failed, we cannot use mmput() to free the mm
495 * because it calls destroy_context()
502 static int copy_mm(unsigned long clone_flags
, struct task_struct
* tsk
)
504 struct mm_struct
* mm
, *oldmm
;
507 tsk
->min_flt
= tsk
->maj_flt
= 0;
508 tsk
->nvcsw
= tsk
->nivcsw
= 0;
511 tsk
->active_mm
= NULL
;
514 * Are we cloning a kernel thread?
516 * We need to steal a active VM for that..
522 if (clone_flags
& CLONE_VM
) {
523 atomic_inc(&oldmm
->mm_users
);
542 static inline struct fs_struct
*__copy_fs_struct(struct fs_struct
*old
)
544 struct fs_struct
*fs
= kmem_cache_alloc(fs_cachep
, GFP_KERNEL
);
545 /* We don't need to lock fs - think why ;-) */
547 atomic_set(&fs
->count
, 1);
548 rwlock_init(&fs
->lock
);
549 fs
->umask
= old
->umask
;
550 read_lock(&old
->lock
);
551 fs
->rootmnt
= mntget(old
->rootmnt
);
552 fs
->root
= dget(old
->root
);
553 fs
->pwdmnt
= mntget(old
->pwdmnt
);
554 fs
->pwd
= dget(old
->pwd
);
556 fs
->altrootmnt
= mntget(old
->altrootmnt
);
557 fs
->altroot
= dget(old
->altroot
);
559 fs
->altrootmnt
= NULL
;
562 read_unlock(&old
->lock
);
567 struct fs_struct
*copy_fs_struct(struct fs_struct
*old
)
569 return __copy_fs_struct(old
);
572 EXPORT_SYMBOL_GPL(copy_fs_struct
);
574 static inline int copy_fs(unsigned long clone_flags
, struct task_struct
* tsk
)
576 if (clone_flags
& CLONE_FS
) {
577 atomic_inc(¤t
->fs
->count
);
580 tsk
->fs
= __copy_fs_struct(current
->fs
);
586 static int count_open_files(struct fdtable
*fdt
)
588 int size
= fdt
->max_fdset
;
591 /* Find the last open fd */
592 for (i
= size
/(8*sizeof(long)); i
> 0; ) {
593 if (fdt
->open_fds
->fds_bits
[--i
])
596 i
= (i
+1) * 8 * sizeof(long);
600 static struct files_struct
*alloc_files(void)
602 struct files_struct
*newf
;
605 newf
= kmem_cache_alloc(files_cachep
, SLAB_KERNEL
);
609 atomic_set(&newf
->count
, 1);
611 spin_lock_init(&newf
->file_lock
);
614 fdt
->max_fds
= NR_OPEN_DEFAULT
;
615 fdt
->max_fdset
= EMBEDDED_FD_SET_SIZE
;
616 fdt
->close_on_exec
= (fd_set
*)&newf
->close_on_exec_init
;
617 fdt
->open_fds
= (fd_set
*)&newf
->open_fds_init
;
618 fdt
->fd
= &newf
->fd_array
[0];
619 INIT_RCU_HEAD(&fdt
->rcu
);
620 fdt
->free_files
= NULL
;
622 rcu_assign_pointer(newf
->fdt
, fdt
);
628 * Allocate a new files structure and copy contents from the
629 * passed in files structure.
630 * errorp will be valid only when the returned files_struct is NULL.
632 static struct files_struct
*dup_fd(struct files_struct
*oldf
, int *errorp
)
634 struct files_struct
*newf
;
635 struct file
**old_fds
, **new_fds
;
636 int open_files
, size
, i
, expand
;
637 struct fdtable
*old_fdt
, *new_fdt
;
640 newf
= alloc_files();
644 spin_lock(&oldf
->file_lock
);
645 old_fdt
= files_fdtable(oldf
);
646 new_fdt
= files_fdtable(newf
);
647 size
= old_fdt
->max_fdset
;
648 open_files
= count_open_files(old_fdt
);
652 * Check whether we need to allocate a larger fd array or fd set.
653 * Note: we're not a clone task, so the open count won't change.
655 if (open_files
> new_fdt
->max_fdset
) {
656 new_fdt
->max_fdset
= 0;
659 if (open_files
> new_fdt
->max_fds
) {
660 new_fdt
->max_fds
= 0;
664 /* if the old fdset gets grown now, we'll only copy up to "size" fds */
666 spin_unlock(&oldf
->file_lock
);
667 spin_lock(&newf
->file_lock
);
668 *errorp
= expand_files(newf
, open_files
-1);
669 spin_unlock(&newf
->file_lock
);
672 new_fdt
= files_fdtable(newf
);
674 * Reacquire the oldf lock and a pointer to its fd table
675 * who knows it may have a new bigger fd table. We need
676 * the latest pointer.
678 spin_lock(&oldf
->file_lock
);
679 old_fdt
= files_fdtable(oldf
);
682 old_fds
= old_fdt
->fd
;
683 new_fds
= new_fdt
->fd
;
685 memcpy(new_fdt
->open_fds
->fds_bits
, old_fdt
->open_fds
->fds_bits
, open_files
/8);
686 memcpy(new_fdt
->close_on_exec
->fds_bits
, old_fdt
->close_on_exec
->fds_bits
, open_files
/8);
688 for (i
= open_files
; i
!= 0; i
--) {
689 struct file
*f
= *old_fds
++;
694 * The fd may be claimed in the fd bitmap but not yet
695 * instantiated in the files array if a sibling thread
696 * is partway through open(). So make sure that this
697 * fd is available to the new process.
699 FD_CLR(open_files
- i
, new_fdt
->open_fds
);
701 rcu_assign_pointer(*new_fds
++, f
);
703 spin_unlock(&oldf
->file_lock
);
705 /* compute the remainder to be cleared */
706 size
= (new_fdt
->max_fds
- open_files
) * sizeof(struct file
*);
708 /* This is long word aligned thus could use a optimized version */
709 memset(new_fds
, 0, size
);
711 if (new_fdt
->max_fdset
> open_files
) {
712 int left
= (new_fdt
->max_fdset
-open_files
)/8;
713 int start
= open_files
/ (8 * sizeof(unsigned long));
715 memset(&new_fdt
->open_fds
->fds_bits
[start
], 0, left
);
716 memset(&new_fdt
->close_on_exec
->fds_bits
[start
], 0, left
);
723 free_fdset (new_fdt
->close_on_exec
, new_fdt
->max_fdset
);
724 free_fdset (new_fdt
->open_fds
, new_fdt
->max_fdset
);
725 free_fd_array(new_fdt
->fd
, new_fdt
->max_fds
);
726 kmem_cache_free(files_cachep
, newf
);
730 static int copy_files(unsigned long clone_flags
, struct task_struct
* tsk
)
732 struct files_struct
*oldf
, *newf
;
736 * A background process may not have any files ...
738 oldf
= current
->files
;
742 if (clone_flags
& CLONE_FILES
) {
743 atomic_inc(&oldf
->count
);
748 * Note: we may be using current for both targets (See exec.c)
749 * This works because we cache current->files (old) as oldf. Don't
753 newf
= dup_fd(oldf
, &error
);
764 * Helper to unshare the files of the current task.
765 * We don't want to expose copy_files internals to
766 * the exec layer of the kernel.
769 int unshare_files(void)
771 struct files_struct
*files
= current
->files
;
776 /* This can race but the race causes us to copy when we don't
777 need to and drop the copy */
778 if(atomic_read(&files
->count
) == 1)
780 atomic_inc(&files
->count
);
783 rc
= copy_files(0, current
);
785 current
->files
= files
;
789 EXPORT_SYMBOL(unshare_files
);
791 static inline int copy_sighand(unsigned long clone_flags
, struct task_struct
* tsk
)
793 struct sighand_struct
*sig
;
795 if (clone_flags
& (CLONE_SIGHAND
| CLONE_THREAD
)) {
796 atomic_inc(¤t
->sighand
->count
);
799 sig
= kmem_cache_alloc(sighand_cachep
, GFP_KERNEL
);
800 rcu_assign_pointer(tsk
->sighand
, sig
);
803 atomic_set(&sig
->count
, 1);
804 memcpy(sig
->action
, current
->sighand
->action
, sizeof(sig
->action
));
808 void __cleanup_sighand(struct sighand_struct
*sighand
)
810 if (atomic_dec_and_test(&sighand
->count
))
811 kmem_cache_free(sighand_cachep
, sighand
);
814 static inline int copy_signal(unsigned long clone_flags
, struct task_struct
* tsk
)
816 struct signal_struct
*sig
;
819 if (clone_flags
& CLONE_THREAD
) {
820 atomic_inc(¤t
->signal
->count
);
821 atomic_inc(¤t
->signal
->live
);
824 sig
= kmem_cache_alloc(signal_cachep
, GFP_KERNEL
);
829 ret
= copy_thread_group_keys(tsk
);
831 kmem_cache_free(signal_cachep
, sig
);
835 atomic_set(&sig
->count
, 1);
836 atomic_set(&sig
->live
, 1);
837 init_waitqueue_head(&sig
->wait_chldexit
);
839 sig
->group_exit_code
= 0;
840 sig
->group_exit_task
= NULL
;
841 sig
->group_stop_count
= 0;
842 sig
->curr_target
= NULL
;
843 init_sigpending(&sig
->shared_pending
);
844 INIT_LIST_HEAD(&sig
->posix_timers
);
846 hrtimer_init(&sig
->real_timer
, CLOCK_MONOTONIC
, HRTIMER_REL
);
847 sig
->it_real_incr
.tv64
= 0;
848 sig
->real_timer
.function
= it_real_fn
;
851 sig
->it_virt_expires
= cputime_zero
;
852 sig
->it_virt_incr
= cputime_zero
;
853 sig
->it_prof_expires
= cputime_zero
;
854 sig
->it_prof_incr
= cputime_zero
;
856 sig
->leader
= 0; /* session leadership doesn't inherit */
857 sig
->tty_old_pgrp
= 0;
859 sig
->utime
= sig
->stime
= sig
->cutime
= sig
->cstime
= cputime_zero
;
860 sig
->nvcsw
= sig
->nivcsw
= sig
->cnvcsw
= sig
->cnivcsw
= 0;
861 sig
->min_flt
= sig
->maj_flt
= sig
->cmin_flt
= sig
->cmaj_flt
= 0;
863 INIT_LIST_HEAD(&sig
->cpu_timers
[0]);
864 INIT_LIST_HEAD(&sig
->cpu_timers
[1]);
865 INIT_LIST_HEAD(&sig
->cpu_timers
[2]);
867 task_lock(current
->group_leader
);
868 memcpy(sig
->rlim
, current
->signal
->rlim
, sizeof sig
->rlim
);
869 task_unlock(current
->group_leader
);
871 if (sig
->rlim
[RLIMIT_CPU
].rlim_cur
!= RLIM_INFINITY
) {
873 * New sole thread in the process gets an expiry time
874 * of the whole CPU time limit.
876 tsk
->it_prof_expires
=
877 secs_to_cputime(sig
->rlim
[RLIMIT_CPU
].rlim_cur
);
879 acct_init_pacct(&sig
->pacct
);
884 void __cleanup_signal(struct signal_struct
*sig
)
886 exit_thread_group_keys(sig
);
887 kmem_cache_free(signal_cachep
, sig
);
890 static inline void cleanup_signal(struct task_struct
*tsk
)
892 struct signal_struct
*sig
= tsk
->signal
;
894 atomic_dec(&sig
->live
);
896 if (atomic_dec_and_test(&sig
->count
))
897 __cleanup_signal(sig
);
900 static inline void copy_flags(unsigned long clone_flags
, struct task_struct
*p
)
902 unsigned long new_flags
= p
->flags
;
904 new_flags
&= ~(PF_SUPERPRIV
| PF_NOFREEZE
);
905 new_flags
|= PF_FORKNOEXEC
;
906 if (!(clone_flags
& CLONE_PTRACE
))
908 p
->flags
= new_flags
;
911 asmlinkage
long sys_set_tid_address(int __user
*tidptr
)
913 current
->clear_child_tid
= tidptr
;
918 static inline void rt_mutex_init_task(struct task_struct
*p
)
920 #ifdef CONFIG_RT_MUTEXES
921 spin_lock_init(&p
->pi_lock
);
922 plist_head_init(&p
->pi_waiters
, &p
->pi_lock
);
923 p
->pi_blocked_on
= NULL
;
928 * This creates a new process as a copy of the old one,
929 * but does not actually start it yet.
931 * It copies the registers, and all the appropriate
932 * parts of the process environment (as per the clone
933 * flags). The actual kick-off is left to the caller.
935 static struct task_struct
*copy_process(unsigned long clone_flags
,
936 unsigned long stack_start
,
937 struct pt_regs
*regs
,
938 unsigned long stack_size
,
939 int __user
*parent_tidptr
,
940 int __user
*child_tidptr
,
944 struct task_struct
*p
= NULL
;
946 if ((clone_flags
& (CLONE_NEWNS
|CLONE_FS
)) == (CLONE_NEWNS
|CLONE_FS
))
947 return ERR_PTR(-EINVAL
);
950 * Thread groups must share signals as well, and detached threads
951 * can only be started up within the thread group.
953 if ((clone_flags
& CLONE_THREAD
) && !(clone_flags
& CLONE_SIGHAND
))
954 return ERR_PTR(-EINVAL
);
957 * Shared signal handlers imply shared VM. By way of the above,
958 * thread groups also imply shared VM. Blocking this case allows
959 * for various simplifications in other code.
961 if ((clone_flags
& CLONE_SIGHAND
) && !(clone_flags
& CLONE_VM
))
962 return ERR_PTR(-EINVAL
);
964 retval
= security_task_create(clone_flags
);
969 p
= dup_task_struct(current
);
973 #ifdef CONFIG_TRACE_IRQFLAGS
974 DEBUG_LOCKS_WARN_ON(!p
->hardirqs_enabled
);
975 DEBUG_LOCKS_WARN_ON(!p
->softirqs_enabled
);
978 if (atomic_read(&p
->user
->processes
) >=
979 p
->signal
->rlim
[RLIMIT_NPROC
].rlim_cur
) {
980 if (!capable(CAP_SYS_ADMIN
) && !capable(CAP_SYS_RESOURCE
) &&
981 p
->user
!= &root_user
)
985 atomic_inc(&p
->user
->__count
);
986 atomic_inc(&p
->user
->processes
);
987 get_group_info(p
->group_info
);
990 * If multiple threads are within copy_process(), then this check
991 * triggers too late. This doesn't hurt, the check is only there
992 * to stop root fork bombs.
994 if (nr_threads
>= max_threads
)
995 goto bad_fork_cleanup_count
;
997 if (!try_module_get(task_thread_info(p
)->exec_domain
->module
))
998 goto bad_fork_cleanup_count
;
1000 if (p
->binfmt
&& !try_module_get(p
->binfmt
->module
))
1001 goto bad_fork_cleanup_put_domain
;
1004 delayacct_tsk_init(p
); /* Must remain after dup_task_struct() */
1005 copy_flags(clone_flags
, p
);
1008 if (clone_flags
& CLONE_PARENT_SETTID
)
1009 if (put_user(p
->pid
, parent_tidptr
))
1010 goto bad_fork_cleanup
;
1012 INIT_LIST_HEAD(&p
->children
);
1013 INIT_LIST_HEAD(&p
->sibling
);
1014 p
->vfork_done
= NULL
;
1015 spin_lock_init(&p
->alloc_lock
);
1017 clear_tsk_thread_flag(p
, TIF_SIGPENDING
);
1018 init_sigpending(&p
->pending
);
1020 p
->utime
= cputime_zero
;
1021 p
->stime
= cputime_zero
;
1023 p
->rchar
= 0; /* I/O counter: bytes read */
1024 p
->wchar
= 0; /* I/O counter: bytes written */
1025 p
->syscr
= 0; /* I/O counter: read syscalls */
1026 p
->syscw
= 0; /* I/O counter: write syscalls */
1027 acct_clear_integrals(p
);
1029 p
->it_virt_expires
= cputime_zero
;
1030 p
->it_prof_expires
= cputime_zero
;
1031 p
->it_sched_expires
= 0;
1032 INIT_LIST_HEAD(&p
->cpu_timers
[0]);
1033 INIT_LIST_HEAD(&p
->cpu_timers
[1]);
1034 INIT_LIST_HEAD(&p
->cpu_timers
[2]);
1036 p
->lock_depth
= -1; /* -1 = no lock */
1037 do_posix_clock_monotonic_gettime(&p
->start_time
);
1039 p
->io_context
= NULL
;
1041 p
->audit_context
= NULL
;
1044 p
->mempolicy
= mpol_copy(p
->mempolicy
);
1045 if (IS_ERR(p
->mempolicy
)) {
1046 retval
= PTR_ERR(p
->mempolicy
);
1047 p
->mempolicy
= NULL
;
1048 goto bad_fork_cleanup_cpuset
;
1050 mpol_fix_fork_child_flag(p
);
1052 #ifdef CONFIG_TRACE_IRQFLAGS
1054 p
->hardirqs_enabled
= 0;
1055 p
->hardirq_enable_ip
= 0;
1056 p
->hardirq_enable_event
= 0;
1057 p
->hardirq_disable_ip
= _THIS_IP_
;
1058 p
->hardirq_disable_event
= 0;
1059 p
->softirqs_enabled
= 1;
1060 p
->softirq_enable_ip
= _THIS_IP_
;
1061 p
->softirq_enable_event
= 0;
1062 p
->softirq_disable_ip
= 0;
1063 p
->softirq_disable_event
= 0;
1064 p
->hardirq_context
= 0;
1065 p
->softirq_context
= 0;
1067 #ifdef CONFIG_LOCKDEP
1068 p
->lockdep_depth
= 0; /* no locks held yet */
1069 p
->curr_chain_key
= 0;
1070 p
->lockdep_recursion
= 0;
1073 rt_mutex_init_task(p
);
1075 #ifdef CONFIG_DEBUG_MUTEXES
1076 p
->blocked_on
= NULL
; /* not blocked yet */
1080 if (clone_flags
& CLONE_THREAD
)
1081 p
->tgid
= current
->tgid
;
1083 if ((retval
= security_task_alloc(p
)))
1084 goto bad_fork_cleanup_policy
;
1085 if ((retval
= audit_alloc(p
)))
1086 goto bad_fork_cleanup_security
;
1087 /* copy all the process information */
1088 if ((retval
= copy_semundo(clone_flags
, p
)))
1089 goto bad_fork_cleanup_audit
;
1090 if ((retval
= copy_files(clone_flags
, p
)))
1091 goto bad_fork_cleanup_semundo
;
1092 if ((retval
= copy_fs(clone_flags
, p
)))
1093 goto bad_fork_cleanup_files
;
1094 if ((retval
= copy_sighand(clone_flags
, p
)))
1095 goto bad_fork_cleanup_fs
;
1096 if ((retval
= copy_signal(clone_flags
, p
)))
1097 goto bad_fork_cleanup_sighand
;
1098 if ((retval
= copy_mm(clone_flags
, p
)))
1099 goto bad_fork_cleanup_signal
;
1100 if ((retval
= copy_keys(clone_flags
, p
)))
1101 goto bad_fork_cleanup_mm
;
1102 if ((retval
= copy_namespace(clone_flags
, p
)))
1103 goto bad_fork_cleanup_keys
;
1104 retval
= copy_thread(0, clone_flags
, stack_start
, stack_size
, p
, regs
);
1106 goto bad_fork_cleanup_namespace
;
1108 p
->set_child_tid
= (clone_flags
& CLONE_CHILD_SETTID
) ? child_tidptr
: NULL
;
1110 * Clear TID on mm_release()?
1112 p
->clear_child_tid
= (clone_flags
& CLONE_CHILD_CLEARTID
) ? child_tidptr
: NULL
;
1113 p
->robust_list
= NULL
;
1114 #ifdef CONFIG_COMPAT
1115 p
->compat_robust_list
= NULL
;
1117 INIT_LIST_HEAD(&p
->pi_state_list
);
1118 p
->pi_state_cache
= NULL
;
1121 * sigaltstack should be cleared when sharing the same VM
1123 if ((clone_flags
& (CLONE_VM
|CLONE_VFORK
)) == CLONE_VM
)
1124 p
->sas_ss_sp
= p
->sas_ss_size
= 0;
1127 * Syscall tracing should be turned off in the child regardless
1130 clear_tsk_thread_flag(p
, TIF_SYSCALL_TRACE
);
1131 #ifdef TIF_SYSCALL_EMU
1132 clear_tsk_thread_flag(p
, TIF_SYSCALL_EMU
);
1135 /* Our parent execution domain becomes current domain
1136 These must match for thread signalling to apply */
1138 p
->parent_exec_id
= p
->self_exec_id
;
1140 /* ok, now we should be set up.. */
1141 p
->exit_signal
= (clone_flags
& CLONE_THREAD
) ? -1 : (clone_flags
& CSIGNAL
);
1142 p
->pdeath_signal
= 0;
1146 * Ok, make it visible to the rest of the system.
1147 * We dont wake it up yet.
1149 p
->group_leader
= p
;
1150 INIT_LIST_HEAD(&p
->thread_group
);
1151 INIT_LIST_HEAD(&p
->ptrace_children
);
1152 INIT_LIST_HEAD(&p
->ptrace_list
);
1154 /* Perform scheduler related setup. Assign this task to a CPU. */
1155 sched_fork(p
, clone_flags
);
1157 /* Need tasklist lock for parent etc handling! */
1158 write_lock_irq(&tasklist_lock
);
1161 * The task hasn't been attached yet, so its cpus_allowed mask will
1162 * not be changed, nor will its assigned CPU.
1164 * The cpus_allowed mask of the parent may have changed after it was
1165 * copied first time - so re-copy it here, then check the child's CPU
1166 * to ensure it is on a valid CPU (and if not, just force it back to
1167 * parent's CPU). This avoids alot of nasty races.
1169 p
->cpus_allowed
= current
->cpus_allowed
;
1170 if (unlikely(!cpu_isset(task_cpu(p
), p
->cpus_allowed
) ||
1171 !cpu_online(task_cpu(p
))))
1172 set_task_cpu(p
, smp_processor_id());
1174 /* CLONE_PARENT re-uses the old parent */
1175 if (clone_flags
& (CLONE_PARENT
|CLONE_THREAD
))
1176 p
->real_parent
= current
->real_parent
;
1178 p
->real_parent
= current
;
1179 p
->parent
= p
->real_parent
;
1181 spin_lock(¤t
->sighand
->siglock
);
1184 * Process group and session signals need to be delivered to just the
1185 * parent before the fork or both the parent and the child after the
1186 * fork. Restart if a signal comes in before we add the new process to
1187 * it's process group.
1188 * A fatal signal pending means that current will exit, so the new
1189 * thread can't slip out of an OOM kill (or normal SIGKILL).
1191 recalc_sigpending();
1192 if (signal_pending(current
)) {
1193 spin_unlock(¤t
->sighand
->siglock
);
1194 write_unlock_irq(&tasklist_lock
);
1195 retval
= -ERESTARTNOINTR
;
1196 goto bad_fork_cleanup_namespace
;
1199 if (clone_flags
& CLONE_THREAD
) {
1200 p
->group_leader
= current
->group_leader
;
1201 list_add_tail_rcu(&p
->thread_group
, &p
->group_leader
->thread_group
);
1203 if (!cputime_eq(current
->signal
->it_virt_expires
,
1205 !cputime_eq(current
->signal
->it_prof_expires
,
1207 current
->signal
->rlim
[RLIMIT_CPU
].rlim_cur
!= RLIM_INFINITY
||
1208 !list_empty(¤t
->signal
->cpu_timers
[0]) ||
1209 !list_empty(¤t
->signal
->cpu_timers
[1]) ||
1210 !list_empty(¤t
->signal
->cpu_timers
[2])) {
1212 * Have child wake up on its first tick to check
1213 * for process CPU timers.
1215 p
->it_prof_expires
= jiffies_to_cputime(1);
1222 p
->ioprio
= current
->ioprio
;
1224 if (likely(p
->pid
)) {
1226 if (unlikely(p
->ptrace
& PT_PTRACED
))
1227 __ptrace_link(p
, current
->parent
);
1229 if (thread_group_leader(p
)) {
1230 p
->signal
->tty
= current
->signal
->tty
;
1231 p
->signal
->pgrp
= process_group(current
);
1232 p
->signal
->session
= current
->signal
->session
;
1233 attach_pid(p
, PIDTYPE_PGID
, process_group(p
));
1234 attach_pid(p
, PIDTYPE_SID
, p
->signal
->session
);
1236 list_add_tail_rcu(&p
->tasks
, &init_task
.tasks
);
1237 __get_cpu_var(process_counts
)++;
1239 attach_pid(p
, PIDTYPE_PID
, p
->pid
);
1244 spin_unlock(¤t
->sighand
->siglock
);
1245 write_unlock_irq(&tasklist_lock
);
1246 proc_fork_connector(p
);
1249 bad_fork_cleanup_namespace
:
1251 bad_fork_cleanup_keys
:
1253 bad_fork_cleanup_mm
:
1256 bad_fork_cleanup_signal
:
1258 bad_fork_cleanup_sighand
:
1259 __cleanup_sighand(p
->sighand
);
1260 bad_fork_cleanup_fs
:
1261 exit_fs(p
); /* blocking */
1262 bad_fork_cleanup_files
:
1263 exit_files(p
); /* blocking */
1264 bad_fork_cleanup_semundo
:
1266 bad_fork_cleanup_audit
:
1268 bad_fork_cleanup_security
:
1269 security_task_free(p
);
1270 bad_fork_cleanup_policy
:
1272 mpol_free(p
->mempolicy
);
1273 bad_fork_cleanup_cpuset
:
1278 module_put(p
->binfmt
->module
);
1279 bad_fork_cleanup_put_domain
:
1280 module_put(task_thread_info(p
)->exec_domain
->module
);
1281 bad_fork_cleanup_count
:
1282 put_group_info(p
->group_info
);
1283 atomic_dec(&p
->user
->processes
);
1288 return ERR_PTR(retval
);
1291 struct pt_regs
* __devinit
__attribute__((weak
)) idle_regs(struct pt_regs
*regs
)
1293 memset(regs
, 0, sizeof(struct pt_regs
));
1297 struct task_struct
* __devinit
fork_idle(int cpu
)
1299 struct task_struct
*task
;
1300 struct pt_regs regs
;
1302 task
= copy_process(CLONE_VM
, 0, idle_regs(®s
), 0, NULL
, NULL
, 0);
1304 return ERR_PTR(-ENOMEM
);
1305 init_idle(task
, cpu
);
1310 static inline int fork_traceflag (unsigned clone_flags
)
1312 if (clone_flags
& CLONE_UNTRACED
)
1314 else if (clone_flags
& CLONE_VFORK
) {
1315 if (current
->ptrace
& PT_TRACE_VFORK
)
1316 return PTRACE_EVENT_VFORK
;
1317 } else if ((clone_flags
& CSIGNAL
) != SIGCHLD
) {
1318 if (current
->ptrace
& PT_TRACE_CLONE
)
1319 return PTRACE_EVENT_CLONE
;
1320 } else if (current
->ptrace
& PT_TRACE_FORK
)
1321 return PTRACE_EVENT_FORK
;
1327 * Ok, this is the main fork-routine.
1329 * It copies the process, and if successful kick-starts
1330 * it and waits for it to finish using the VM if required.
1332 long do_fork(unsigned long clone_flags
,
1333 unsigned long stack_start
,
1334 struct pt_regs
*regs
,
1335 unsigned long stack_size
,
1336 int __user
*parent_tidptr
,
1337 int __user
*child_tidptr
)
1339 struct task_struct
*p
;
1341 struct pid
*pid
= alloc_pid();
1347 if (unlikely(current
->ptrace
)) {
1348 trace
= fork_traceflag (clone_flags
);
1350 clone_flags
|= CLONE_PTRACE
;
1353 p
= copy_process(clone_flags
, stack_start
, regs
, stack_size
, parent_tidptr
, child_tidptr
, nr
);
1355 * Do this prior waking up the new thread - the thread pointer
1356 * might get invalid after that point, if the thread exits quickly.
1359 struct completion vfork
;
1361 if (clone_flags
& CLONE_VFORK
) {
1362 p
->vfork_done
= &vfork
;
1363 init_completion(&vfork
);
1366 if ((p
->ptrace
& PT_PTRACED
) || (clone_flags
& CLONE_STOPPED
)) {
1368 * We'll start up with an immediate SIGSTOP.
1370 sigaddset(&p
->pending
.signal
, SIGSTOP
);
1371 set_tsk_thread_flag(p
, TIF_SIGPENDING
);
1374 if (!(clone_flags
& CLONE_STOPPED
))
1375 wake_up_new_task(p
, clone_flags
);
1377 p
->state
= TASK_STOPPED
;
1379 if (unlikely (trace
)) {
1380 current
->ptrace_message
= nr
;
1381 ptrace_notify ((trace
<< 8) | SIGTRAP
);
1384 if (clone_flags
& CLONE_VFORK
) {
1385 wait_for_completion(&vfork
);
1386 if (unlikely (current
->ptrace
& PT_TRACE_VFORK_DONE
))
1387 ptrace_notify ((PTRACE_EVENT_VFORK_DONE
<< 8) | SIGTRAP
);
1396 #ifndef ARCH_MIN_MMSTRUCT_ALIGN
1397 #define ARCH_MIN_MMSTRUCT_ALIGN 0
1400 static void sighand_ctor(void *data
, kmem_cache_t
*cachep
, unsigned long flags
)
1402 struct sighand_struct
*sighand
= data
;
1404 if ((flags
& (SLAB_CTOR_VERIFY
| SLAB_CTOR_CONSTRUCTOR
)) ==
1405 SLAB_CTOR_CONSTRUCTOR
)
1406 spin_lock_init(&sighand
->siglock
);
1409 void __init
proc_caches_init(void)
1411 sighand_cachep
= kmem_cache_create("sighand_cache",
1412 sizeof(struct sighand_struct
), 0,
1413 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
|SLAB_DESTROY_BY_RCU
,
1414 sighand_ctor
, NULL
);
1415 signal_cachep
= kmem_cache_create("signal_cache",
1416 sizeof(struct signal_struct
), 0,
1417 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
, NULL
);
1418 files_cachep
= kmem_cache_create("files_cache",
1419 sizeof(struct files_struct
), 0,
1420 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
, NULL
);
1421 fs_cachep
= kmem_cache_create("fs_cache",
1422 sizeof(struct fs_struct
), 0,
1423 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
, NULL
);
1424 vm_area_cachep
= kmem_cache_create("vm_area_struct",
1425 sizeof(struct vm_area_struct
), 0,
1426 SLAB_PANIC
, NULL
, NULL
);
1427 mm_cachep
= kmem_cache_create("mm_struct",
1428 sizeof(struct mm_struct
), ARCH_MIN_MMSTRUCT_ALIGN
,
1429 SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
, NULL
);
1434 * Check constraints on flags passed to the unshare system call and
1435 * force unsharing of additional process context as appropriate.
1437 static inline void check_unshare_flags(unsigned long *flags_ptr
)
1440 * If unsharing a thread from a thread group, must also
1443 if (*flags_ptr
& CLONE_THREAD
)
1444 *flags_ptr
|= CLONE_VM
;
1447 * If unsharing vm, must also unshare signal handlers.
1449 if (*flags_ptr
& CLONE_VM
)
1450 *flags_ptr
|= CLONE_SIGHAND
;
1453 * If unsharing signal handlers and the task was created
1454 * using CLONE_THREAD, then must unshare the thread
1456 if ((*flags_ptr
& CLONE_SIGHAND
) &&
1457 (atomic_read(¤t
->signal
->count
) > 1))
1458 *flags_ptr
|= CLONE_THREAD
;
1461 * If unsharing namespace, must also unshare filesystem information.
1463 if (*flags_ptr
& CLONE_NEWNS
)
1464 *flags_ptr
|= CLONE_FS
;
1468 * Unsharing of tasks created with CLONE_THREAD is not supported yet
1470 static int unshare_thread(unsigned long unshare_flags
)
1472 if (unshare_flags
& CLONE_THREAD
)
1479 * Unshare the filesystem structure if it is being shared
1481 static int unshare_fs(unsigned long unshare_flags
, struct fs_struct
**new_fsp
)
1483 struct fs_struct
*fs
= current
->fs
;
1485 if ((unshare_flags
& CLONE_FS
) &&
1486 (fs
&& atomic_read(&fs
->count
) > 1)) {
1487 *new_fsp
= __copy_fs_struct(current
->fs
);
1496 * Unshare the namespace structure if it is being shared
1498 static int unshare_namespace(unsigned long unshare_flags
, struct namespace **new_nsp
, struct fs_struct
*new_fs
)
1500 struct namespace *ns
= current
->namespace;
1502 if ((unshare_flags
& CLONE_NEWNS
) &&
1503 (ns
&& atomic_read(&ns
->count
) > 1)) {
1504 if (!capable(CAP_SYS_ADMIN
))
1507 *new_nsp
= dup_namespace(current
, new_fs
? new_fs
: current
->fs
);
1516 * Unsharing of sighand for tasks created with CLONE_SIGHAND is not
1519 static int unshare_sighand(unsigned long unshare_flags
, struct sighand_struct
**new_sighp
)
1521 struct sighand_struct
*sigh
= current
->sighand
;
1523 if ((unshare_flags
& CLONE_SIGHAND
) &&
1524 (sigh
&& atomic_read(&sigh
->count
) > 1))
1531 * Unshare vm if it is being shared
1533 static int unshare_vm(unsigned long unshare_flags
, struct mm_struct
**new_mmp
)
1535 struct mm_struct
*mm
= current
->mm
;
1537 if ((unshare_flags
& CLONE_VM
) &&
1538 (mm
&& atomic_read(&mm
->mm_users
) > 1)) {
1546 * Unshare file descriptor table if it is being shared
1548 static int unshare_fd(unsigned long unshare_flags
, struct files_struct
**new_fdp
)
1550 struct files_struct
*fd
= current
->files
;
1553 if ((unshare_flags
& CLONE_FILES
) &&
1554 (fd
&& atomic_read(&fd
->count
) > 1)) {
1555 *new_fdp
= dup_fd(fd
, &error
);
1564 * Unsharing of semundo for tasks created with CLONE_SYSVSEM is not
1567 static int unshare_semundo(unsigned long unshare_flags
, struct sem_undo_list
**new_ulistp
)
1569 if (unshare_flags
& CLONE_SYSVSEM
)
1576 * unshare allows a process to 'unshare' part of the process
1577 * context which was originally shared using clone. copy_*
1578 * functions used by do_fork() cannot be used here directly
1579 * because they modify an inactive task_struct that is being
1580 * constructed. Here we are modifying the current, active,
1583 asmlinkage
long sys_unshare(unsigned long unshare_flags
)
1586 struct fs_struct
*fs
, *new_fs
= NULL
;
1587 struct namespace *ns
, *new_ns
= NULL
;
1588 struct sighand_struct
*sigh
, *new_sigh
= NULL
;
1589 struct mm_struct
*mm
, *new_mm
= NULL
, *active_mm
= NULL
;
1590 struct files_struct
*fd
, *new_fd
= NULL
;
1591 struct sem_undo_list
*new_ulist
= NULL
;
1593 check_unshare_flags(&unshare_flags
);
1595 /* Return -EINVAL for all unsupported flags */
1597 if (unshare_flags
& ~(CLONE_THREAD
|CLONE_FS
|CLONE_NEWNS
|CLONE_SIGHAND
|
1598 CLONE_VM
|CLONE_FILES
|CLONE_SYSVSEM
))
1599 goto bad_unshare_out
;
1601 if ((err
= unshare_thread(unshare_flags
)))
1602 goto bad_unshare_out
;
1603 if ((err
= unshare_fs(unshare_flags
, &new_fs
)))
1604 goto bad_unshare_cleanup_thread
;
1605 if ((err
= unshare_namespace(unshare_flags
, &new_ns
, new_fs
)))
1606 goto bad_unshare_cleanup_fs
;
1607 if ((err
= unshare_sighand(unshare_flags
, &new_sigh
)))
1608 goto bad_unshare_cleanup_ns
;
1609 if ((err
= unshare_vm(unshare_flags
, &new_mm
)))
1610 goto bad_unshare_cleanup_sigh
;
1611 if ((err
= unshare_fd(unshare_flags
, &new_fd
)))
1612 goto bad_unshare_cleanup_vm
;
1613 if ((err
= unshare_semundo(unshare_flags
, &new_ulist
)))
1614 goto bad_unshare_cleanup_fd
;
1616 if (new_fs
|| new_ns
|| new_sigh
|| new_mm
|| new_fd
|| new_ulist
) {
1622 current
->fs
= new_fs
;
1627 ns
= current
->namespace;
1628 current
->namespace = new_ns
;
1633 sigh
= current
->sighand
;
1634 rcu_assign_pointer(current
->sighand
, new_sigh
);
1640 active_mm
= current
->active_mm
;
1641 current
->mm
= new_mm
;
1642 current
->active_mm
= new_mm
;
1643 activate_mm(active_mm
, new_mm
);
1648 fd
= current
->files
;
1649 current
->files
= new_fd
;
1653 task_unlock(current
);
1656 bad_unshare_cleanup_fd
:
1658 put_files_struct(new_fd
);
1660 bad_unshare_cleanup_vm
:
1664 bad_unshare_cleanup_sigh
:
1666 if (atomic_dec_and_test(&new_sigh
->count
))
1667 kmem_cache_free(sighand_cachep
, new_sigh
);
1669 bad_unshare_cleanup_ns
:
1671 put_namespace(new_ns
);
1673 bad_unshare_cleanup_fs
:
1675 put_fs_struct(new_fs
);
1677 bad_unshare_cleanup_thread
: