xref: /openbmc/linux/io_uring/epoll.c (revision 0545810f)
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)
16 struct io_epoll {
17 	struct file			*file;
18 	int				epfd;
19 	int				op;
20 	int				fd;
21 	struct epoll_event		event;
22 };
23 
24 int 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 
50 int 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
66