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 struct io_epoll { 16 struct file *file; 17 int epfd; 18 int op; 19 int fd; 20 struct epoll_event event; 21 }; 22 23 struct io_epoll_wait { 24 struct file *file; 25 int maxevents; 26 struct epoll_event __user *events; 27 }; 28 29 int 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(epoll->op)) { 41 struct epoll_event __user *ev; 42 43 ev = u64_to_user_ptr(READ_ONCE(sqe->addr)); 44 if (copy_from_user(&epoll->event, ev, sizeof(*ev))) 45 return -EFAULT; 46 } 47 48 return 0; 49 } 50 51 int 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 bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; 55 struct epoll_key key; 56 int ret; 57 58 CLASS(fd, f)(ie->epfd); 59 if (fd_empty(f)) 60 return -EBADF; 61 62 CLASS(fd, tf)(ie->fd); 63 if (fd_empty(tf)) 64 return -EBADF; 65 /* disallow adding an epoll context to another epoll context */ 66 if (ie->op == EPOLL_CTL_ADD && is_file_epoll(fd_file(tf))) 67 return -EINVAL; 68 69 key.file = fd_file(tf); 70 key.fd = ie->fd; 71 ret = do_epoll_ctl_file(fd_file(f), ie->op, &key, &ie->event, force_nonblock); 72 if (force_nonblock && ret == -EAGAIN) 73 return -EAGAIN; 74 75 if (ret < 0) 76 req_set_fail(req); 77 io_req_set_res(req, ret, 0); 78 return IOU_COMPLETE; 79 } 80 81 int io_epoll_wait_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) 82 { 83 struct io_epoll_wait *iew = io_kiocb_to_cmd(req, struct io_epoll_wait); 84 85 if (sqe->off || sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in) 86 return -EINVAL; 87 88 iew->maxevents = READ_ONCE(sqe->len); 89 iew->events = u64_to_user_ptr(READ_ONCE(sqe->addr)); 90 return 0; 91 } 92 93 int io_epoll_wait(struct io_kiocb *req, unsigned int issue_flags) 94 { 95 struct io_epoll_wait *iew = io_kiocb_to_cmd(req, struct io_epoll_wait); 96 int ret; 97 98 ret = epoll_sendevents(req->file, iew->events, iew->maxevents); 99 if (ret == 0) 100 return -EAGAIN; 101 if (ret < 0) 102 req_set_fail(req); 103 104 io_req_set_res(req, ret, 0); 105 return IOU_COMPLETE; 106 } 107