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
15struct io_epoll {
16 struct file *file;
17 int epfd;
18 int op;
19 int fd;
20 struct epoll_event event;
21};
22
23struct io_epoll_wait {
24 struct file *file;
25 int maxevents;
26 struct epoll_event __user *events;
27};
28
29int io_epoll_ctl_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
30{
31 struct io_epoll *epoll = io_kiocb_to_cmd(req, struct io_epoll);
32
33 if (sqe->buf_index || sqe->splice_fd_in)
34 return -EINVAL;
35
36 epoll->epfd = READ_ONCE(sqe->fd);
37 epoll->op = READ_ONCE(sqe->len);
38 epoll->fd = READ_ONCE(sqe->off);
39
40 if (ep_op_has_event(op: epoll->op)) {
41 struct epoll_event __user *ev;
42
43 ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
44 if (copy_from_user(to: &epoll->event, from: ev, n: sizeof(*ev)))
45 return -EFAULT;
46 }
47
48 return 0;
49}
50
51int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
52{
53 struct io_epoll *ie = io_kiocb_to_cmd(req, struct io_epoll);
54 int ret;
55 bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
56
57 ret = do_epoll_ctl(epfd: ie->epfd, op: ie->op, fd: ie->fd, epds: &ie->event, nonblock: force_nonblock);
58 if (force_nonblock && ret == -EAGAIN)
59 return -EAGAIN;
60
61 if (ret < 0)
62 req_set_fail(req);
63 io_req_set_res(req, res: ret, cflags: 0);
64 return IOU_COMPLETE;
65}
66
67int io_epoll_wait_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
68{
69 struct io_epoll_wait *iew = io_kiocb_to_cmd(req, struct io_epoll_wait);
70
71 if (sqe->off || sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in)
72 return -EINVAL;
73
74 iew->maxevents = READ_ONCE(sqe->len);
75 iew->events = u64_to_user_ptr(READ_ONCE(sqe->addr));
76 return 0;
77}
78
79int io_epoll_wait(struct io_kiocb *req, unsigned int issue_flags)
80{
81 struct io_epoll_wait *iew = io_kiocb_to_cmd(req, struct io_epoll_wait);
82 int ret;
83
84 ret = epoll_sendevents(file: req->file, events: iew->events, maxevents: iew->maxevents);
85 if (ret == 0)
86 return -EAGAIN;
87 if (ret < 0)
88 req_set_fail(req);
89
90 io_req_set_res(req, res: ret, cflags: 0);
91 return IOU_COMPLETE;
92}
93