48 struct pid init_struct_pid = {
105 void put_pid(struct pid *pid)  in put_pid()  argument
109 	if (!pid)  in put_pid()
112 	ns = pid->numbers[pid->level].ns;  in put_pid()
113 	if (refcount_dec_and_test(&pid->count)) {  in put_pid()
114 		kmem_cache_free(ns->pid_cachep, pid);  in put_pid()
122 	struct pid *pid = container_of(rhp, struct pid, rcu);  in delayed_put_pid()  local
123 	put_pid(pid);  in delayed_put_pid()
126 void free_pid(struct pid *pid)  in free_pid()  argument
133 	for (i = 0; i <= pid->level; i++) {  in free_pid()
134 		struct upid *upid = pid->numbers + i;  in free_pid()
156 	call_rcu(&pid->rcu, delayed_put_pid);  in free_pid()
159 struct pid *alloc_pid(struct pid_namespace *ns, pid_t *set_tid,  in alloc_pid()
162 	struct pid *pid;  in alloc_pid()  local
180 	pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL);  in alloc_pid()
181 	if (!pid)  in alloc_pid()
185 	pid->level = ns->level;  in alloc_pid()
244 		pid->numbers[i].nr = nr;  in alloc_pid()
245 		pid->numbers[i].ns = tmp;  in alloc_pid()
260 	refcount_set(&pid->count, 1);  in alloc_pid()
261 	spin_lock_init(&pid->lock);  in alloc_pid()
263 		INIT_HLIST_HEAD(&pid->tasks[type]);  in alloc_pid()
265 	init_waitqueue_head(&pid->wait_pidfd);  in alloc_pid()
266 	INIT_HLIST_HEAD(&pid->inodes);  in alloc_pid()
268 	upid = pid->numbers + ns->level;  in alloc_pid()
272 	for ( ; upid >= pid->numbers; --upid) {  in alloc_pid()
274 		idr_replace(&upid->ns->idr, pid, upid->nr);  in alloc_pid()
279 	return pid;  in alloc_pid()
288 		upid = pid->numbers + i;  in alloc_pid()
298 	kmem_cache_free(ns->pid_cachep, pid);  in alloc_pid()
309 struct pid *find_pid_ns(int nr, struct pid_namespace *ns)  in find_pid_ns()
315 struct pid *find_vpid(int nr)  in find_vpid()
321 static struct pid **task_pid_ptr(struct task_struct *task, enum pid_type type)  in task_pid_ptr()
333 	struct pid *pid = *task_pid_ptr(task, type);  in attach_pid()  local
334 	hlist_add_head_rcu(&task->pid_links[type], &pid->tasks[type]);  in attach_pid()
338 			struct pid *new)  in __change_pid()
340 	struct pid **pid_ptr = task_pid_ptr(task, type);  in __change_pid()
341 	struct pid *pid;  in __change_pid()  local
344 	pid = *pid_ptr;  in __change_pid()
350 		if (pid_has_task(pid, tmp))  in __change_pid()
353 	free_pid(pid);  in __change_pid()
362 		struct pid *pid)  in change_pid()  argument
364 	__change_pid(task, type, pid);  in change_pid()
370 	struct pid *pid1 = left->thread_pid;  in exchange_tids()
371 	struct pid *pid2 = right->thread_pid;  in exchange_tids()
383 	WRITE_ONCE(left->pid, pid_nr(pid2));  in exchange_tids()
384 	WRITE_ONCE(right->pid, pid_nr(pid1));  in exchange_tids()
396 struct task_struct *pid_task(struct pid *pid, enum pid_type type)  in pid_task()  argument
399 	if (pid) {  in pid_task()
401 		first = rcu_dereference_check(hlist_first_rcu(&pid->tasks[type]),  in pid_task()
438 struct pid *get_task_pid(struct task_struct *task, enum pid_type type)  in get_task_pid()
440 	struct pid *pid;  in get_task_pid()  local
442 	pid = get_pid(rcu_dereference(*task_pid_ptr(task, type)));  in get_task_pid()
444 	return pid;  in get_task_pid()
448 struct task_struct *get_pid_task(struct pid *pid, enum pid_type type)  in get_pid_task()  argument
452 	result = pid_task(pid, type);  in get_pid_task()
460 struct pid *find_get_pid(pid_t nr)  in find_get_pid()
462 	struct pid *pid;  in find_get_pid()  local
465 	pid = get_pid(find_vpid(nr));  in find_get_pid()
468 	return pid;  in find_get_pid()
472 pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns)  in pid_nr_ns()  argument
477 	if (pid && ns->level <= pid->level) {  in pid_nr_ns()
478 		upid = &pid->numbers[ns->level];  in pid_nr_ns()
486 pid_t pid_vnr(struct pid *pid)  in pid_vnr()  argument
488 	return pid_nr_ns(pid, task_active_pid_ns(current));  in pid_vnr()
518 struct pid *find_ge_pid(int nr, struct pid_namespace *ns)  in find_ge_pid()
523 struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags)  in pidfd_get_pid()
526 	struct pid *pid;  in pidfd_get_pid()  local
532 	pid = pidfd_pid(f.file);  in pidfd_get_pid()
533 	if (!IS_ERR(pid)) {  in pidfd_get_pid()
534 		get_pid(pid);  in pidfd_get_pid()
539 	return pid;  in pidfd_get_pid()
562 	struct pid *pid;  in pidfd_get_task()  local
565 	pid = pidfd_get_pid(pidfd, &f_flags);  in pidfd_get_task()
566 	if (IS_ERR(pid))  in pidfd_get_task()
567 		return ERR_CAST(pid);  in pidfd_get_task()
569 	task = get_pid_task(pid, PIDTYPE_TGID);  in pidfd_get_task()
570 	put_pid(pid);  in pidfd_get_task()
594 int pidfd_create(struct pid *pid, unsigned int flags)  in pidfd_create()  argument
598 	if (!pid || !pid_has_task(pid, PIDTYPE_TGID))  in pidfd_create()
604 	fd = anon_inode_getfd("[pidfd]", &pidfd_fops, get_pid(pid),  in pidfd_create()
607 		put_pid(pid);  in pidfd_create()
628 SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)  in SYSCALL_DEFINE2()  argument
631 	struct pid *p;  in SYSCALL_DEFINE2()
636 	if (pid <= 0)  in SYSCALL_DEFINE2()
639 	p = find_get_pid(pid);  in SYSCALL_DEFINE2()
663 	init_pid_ns.pid_cachep = KMEM_CACHE(pid,  in pid_idr_init()
686 static int pidfd_getfd(struct pid *pid, int fd)  in pidfd_getfd()  argument
692 	task = get_pid_task(pid, PIDTYPE_PID);  in pidfd_getfd()
726 	struct pid *pid;  in SYSCALL_DEFINE3()  local
738 	pid = pidfd_pid(f.file);  in SYSCALL_DEFINE3()
739 	if (IS_ERR(pid))  in SYSCALL_DEFINE3()
740 		ret = PTR_ERR(pid);  in SYSCALL_DEFINE3()
742 		ret = pidfd_getfd(pid, fd);  in SYSCALL_DEFINE3()