49 struct pid init_struct_pid = {
112 void put_pid(struct pid *pid)  in put_pid()  argument
116 	if (!pid)  in put_pid()
119 	ns = pid->numbers[pid->level].ns;  in put_pid()
120 	if (refcount_dec_and_test(&pid->count)) {  in put_pid()
121 		kmem_cache_free(ns->pid_cachep, pid);  in put_pid()
129 	struct pid *pid = container_of(rhp, struct pid, rcu);  in delayed_put_pid()  local
130 	put_pid(pid);  in delayed_put_pid()
133 void free_pid(struct pid *pid)  in free_pid()  argument
140 	for (i = 0; i <= pid->level; i++) {  in free_pid()
141 		struct upid *upid = pid->numbers + i;  in free_pid()
163 	call_rcu(&pid->rcu, delayed_put_pid);  in free_pid()
166 struct pid *alloc_pid(struct pid_namespace *ns, pid_t *set_tid,  in alloc_pid()
169 	struct pid *pid;  in alloc_pid()  local
187 	pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL);  in alloc_pid()
188 	if (!pid)  in alloc_pid()
192 	pid->level = ns->level;  in alloc_pid()
251 		pid->numbers[i].nr = nr;  in alloc_pid()
252 		pid->numbers[i].ns = tmp;  in alloc_pid()
267 	refcount_set(&pid->count, 1);  in alloc_pid()
268 	spin_lock_init(&pid->lock);  in alloc_pid()
270 		INIT_HLIST_HEAD(&pid->tasks[type]);  in alloc_pid()
272 	init_waitqueue_head(&pid->wait_pidfd);  in alloc_pid()
273 	INIT_HLIST_HEAD(&pid->inodes);  in alloc_pid()
275 	upid = pid->numbers + ns->level;  in alloc_pid()
279 	pid->stashed = NULL;  in alloc_pid()
280 	pid->ino = ++pidfs_ino;  in alloc_pid()
281 	for ( ; upid >= pid->numbers; --upid) {  in alloc_pid()
283 		idr_replace(&upid->ns->idr, pid, upid->nr);  in alloc_pid()
288 	return pid;  in alloc_pid()
297 		upid = pid->numbers + i;  in alloc_pid()
307 	kmem_cache_free(ns->pid_cachep, pid);  in alloc_pid()
318 struct pid *find_pid_ns(int nr, struct pid_namespace *ns)  in find_pid_ns()
324 struct pid *find_vpid(int nr)  in find_vpid()
330 static struct pid **task_pid_ptr(struct task_struct *task, enum pid_type type)  in task_pid_ptr()
342 	struct pid *pid = *task_pid_ptr(task, type);  in attach_pid()  local
343 	hlist_add_head_rcu(&task->pid_links[type], &pid->tasks[type]);  in attach_pid()
347 			struct pid *new)  in __change_pid()
349 	struct pid **pid_ptr = task_pid_ptr(task, type);  in __change_pid()
350 	struct pid *pid;  in __change_pid()  local
353 	pid = *pid_ptr;  in __change_pid()
359 		WARN_ON_ONCE(pid_has_task(pid, PIDTYPE_PID));  in __change_pid()
360 		wake_up_all(&pid->wait_pidfd);  in __change_pid()
364 		if (pid_has_task(pid, tmp))  in __change_pid()
367 	free_pid(pid);  in __change_pid()
376 		struct pid *pid)  in change_pid()  argument
378 	__change_pid(task, type, pid);  in change_pid()
384 	struct pid *pid1 = left->thread_pid;  in exchange_tids()
385 	struct pid *pid2 = right->thread_pid;  in exchange_tids()
397 	WRITE_ONCE(left->pid, pid_nr(pid2));  in exchange_tids()
398 	WRITE_ONCE(right->pid, pid_nr(pid1));  in exchange_tids()
409 struct task_struct *pid_task(struct pid *pid, enum pid_type type)  in pid_task()  argument
412 	if (pid) {  in pid_task()
414 		first = rcu_dereference_check(hlist_first_rcu(&pid->tasks[type]),  in pid_task()
451 struct pid *get_task_pid(struct task_struct *task, enum pid_type type)  in get_task_pid()
453 	struct pid *pid;  in get_task_pid()  local
455 	pid = get_pid(rcu_dereference(*task_pid_ptr(task, type)));  in get_task_pid()
457 	return pid;  in get_task_pid()
461 struct task_struct *get_pid_task(struct pid *pid, enum pid_type type)  in get_pid_task()  argument
465 	result = pid_task(pid, type);  in get_pid_task()
473 struct pid *find_get_pid(pid_t nr)  in find_get_pid()
475 	struct pid *pid;  in find_get_pid()  local
478 	pid = get_pid(find_vpid(nr));  in find_get_pid()
481 	return pid;  in find_get_pid()
485 pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns)  in pid_nr_ns()  argument
490 	if (pid && ns->level <= pid->level) {  in pid_nr_ns()
491 		upid = &pid->numbers[ns->level];  in pid_nr_ns()
499 pid_t pid_vnr(struct pid *pid)  in pid_vnr()  argument
501 	return pid_nr_ns(pid, task_active_pid_ns(current));  in pid_vnr()
531 struct pid *find_ge_pid(int nr, struct pid_namespace *ns)  in find_ge_pid()
537 struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags)  in pidfd_get_pid()
540 	struct pid *pid;  in pidfd_get_pid()  local
546 	pid = pidfd_pid(fd_file(f));  in pidfd_get_pid()
547 	if (!IS_ERR(pid)) {  in pidfd_get_pid()
548 		get_pid(pid);  in pidfd_get_pid()
553 	return pid;  in pidfd_get_pid()
571 	struct pid *pid;  in pidfd_get_task()  local
574 	pid = pidfd_get_pid(pidfd, &f_flags);  in pidfd_get_task()
575 	if (IS_ERR(pid))  in pidfd_get_task()
576 		return ERR_CAST(pid);  in pidfd_get_task()
578 	task = get_pid_task(pid, PIDTYPE_TGID);  in pidfd_get_task()
579 	put_pid(pid);  in pidfd_get_task()
603 static int pidfd_create(struct pid *pid, unsigned int flags)  in pidfd_create()  argument
608 	pidfd = pidfd_prepare(pid, flags, &pidfd_file);  in pidfd_create()
629 SYSCALL_DEFINE2(pidfd_open, pid_t, pid, unsigned int, flags)  in SYSCALL_DEFINE2()  argument
632 	struct pid *p;  in SYSCALL_DEFINE2()
637 	if (pid <= 0)  in SYSCALL_DEFINE2()
640 	p = find_get_pid(pid);  in SYSCALL_DEFINE2()
665 			struct_size_t(struct pid, numbers, 1),  in pid_idr_init()
666 			__alignof__(struct pid),  in pid_idr_init()
709 static int pidfd_getfd(struct pid *pid, int fd)  in pidfd_getfd()  argument
715 	task = get_pid_task(pid, PIDTYPE_PID);  in pidfd_getfd()
749 	struct pid *pid;  in SYSCALL_DEFINE3()  local
761 	pid = pidfd_pid(fd_file(f));  in SYSCALL_DEFINE3()
762 	if (IS_ERR(pid))  in SYSCALL_DEFINE3()
763 		ret = PTR_ERR(pid);  in SYSCALL_DEFINE3()
765 		ret = pidfd_getfd(pid, fd);  in SYSCALL_DEFINE3()