1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/kernel.h>
 3#include <linux/errno.h>
 4#include <linux/file.h>
 5#include <linux/fs.h>
 6#include <linux/uaccess.h>
 7#include <linux/io_uring.h>
 8#include <linux/eventpoll.h>
 9
10#include <uapi/linux/io_uring.h>
11
12#include "io_uring.h"
13#include "epoll.h"
14
15#if defined(CONFIG_EPOLL)
16struct io_epoll {
17	struct file			*file;
18	int				epfd;
19	int				op;
20	int				fd;
21	struct epoll_event		event;
22};
23
24int io_epoll_ctl_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
25{
26	struct io_epoll *epoll = io_kiocb_to_cmd(req, struct io_epoll);
27
28	pr_warn_once("%s: epoll_ctl support in io_uring is deprecated and will "
29		     "be removed in a future Linux kernel version.\n",
30		     current->comm);
31
32	if (sqe->buf_index || sqe->splice_fd_in)
33		return -EINVAL;
34
35	epoll->epfd = READ_ONCE(sqe->fd);
36	epoll->op = READ_ONCE(sqe->len);
37	epoll->fd = READ_ONCE(sqe->off);
38
39	if (ep_op_has_event(epoll->op)) {
40		struct epoll_event __user *ev;
41
42		ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
43		if (copy_from_user(&epoll->event, ev, sizeof(*ev)))
44			return -EFAULT;
45	}
46
47	return 0;
48}
49
50int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
51{
52	struct io_epoll *ie = io_kiocb_to_cmd(req, struct io_epoll);
53	int ret;
54	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
55
56	ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
57	if (force_nonblock && ret == -EAGAIN)
58		return -EAGAIN;
59
60	if (ret < 0)
61		req_set_fail(req);
62	io_req_set_res(req, ret, 0);
63	return IOU_OK;
64}
65#endif