xref: /openbmc/linux/io_uring/epoll.c (revision 590e7b28)
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 	if (sqe->buf_index || sqe->splice_fd_in)
29 		return -EINVAL;
30 
31 	epoll->epfd = READ_ONCE(sqe->fd);
32 	epoll->op = READ_ONCE(sqe->len);
33 	epoll->fd = READ_ONCE(sqe->off);
34 
35 	if (ep_op_has_event(epoll->op)) {
36 		struct epoll_event __user *ev;
37 
38 		ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
39 		if (copy_from_user(&epoll->event, ev, sizeof(*ev)))
40 			return -EFAULT;
41 	}
42 
43 	return 0;
44 }
45 
46 int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
47 {
48 	struct io_epoll *ie = io_kiocb_to_cmd(req, struct io_epoll);
49 	int ret;
50 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
51 
52 	ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
53 	if (force_nonblock && ret == -EAGAIN)
54 		return -EAGAIN;
55 
56 	if (ret < 0)
57 		req_set_fail(req);
58 	io_req_set_res(req, ret, 0);
59 	return IOU_OK;
60 }
61 #endif
62