xref: /openbmc/linux/io_uring/epoll.c (revision 2154aca2)
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