mirror of
https://github.com/linux-msm/laptops-kernel.git
synced 2026-08-13 14:19:53 -07:00
Jens Axboe
9db03d2116
Turns out that my naive assumption that surely nobody is using io_uring
to manage nested epoll instances was wrong - libuv is in fact doing that
very thing. Since we have users in the wild using that feature, we
cannot remove it from upstream. Revert the commit that introduced that
limitation.
This reverts commit cfa1539b24.
Link: https://lore.kernel.org/io-uring/605939add4dfb674bd7ab39ef8dbd3fd22e754e4.camel@xry111.site/
Reported-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
104 lines
2.3 KiB
C
104 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/file.h>
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#include <linux/fs.h>
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#include <linux/uaccess.h>
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#include <linux/io_uring.h>
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#include <linux/eventpoll.h>
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#include <uapi/linux/io_uring.h>
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#include "io_uring.h"
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#include "epoll.h"
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struct io_epoll {
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struct file *file;
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int epfd;
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int op;
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int fd;
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struct epoll_event event;
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};
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struct io_epoll_wait {
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struct file *file;
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int maxevents;
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struct epoll_event __user *events;
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};
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int io_epoll_ctl_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
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{
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struct io_epoll *epoll = io_kiocb_to_cmd(req, struct io_epoll);
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if (sqe->buf_index || sqe->splice_fd_in)
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return -EINVAL;
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epoll->epfd = READ_ONCE(sqe->fd);
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epoll->op = READ_ONCE(sqe->len);
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epoll->fd = READ_ONCE(sqe->off);
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if (ep_op_has_event(epoll->op)) {
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struct epoll_event __user *ev;
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ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
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if (copy_from_user(&epoll->event, ev, sizeof(*ev)))
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return -EFAULT;
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}
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return 0;
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}
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int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
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{
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struct io_epoll *ie = io_kiocb_to_cmd(req, struct io_epoll);
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bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
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struct epoll_key key;
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int ret;
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CLASS(fd, f)(ie->epfd);
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if (fd_empty(f))
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return -EBADF;
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CLASS(fd, tf)(ie->fd);
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if (fd_empty(tf))
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return -EBADF;
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key.file = fd_file(tf);
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key.fd = ie->fd;
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ret = do_epoll_ctl_file(fd_file(f), ie->op, &key, &ie->event, force_nonblock);
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if (force_nonblock && ret == -EAGAIN)
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return -EAGAIN;
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if (ret < 0)
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req_set_fail(req);
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io_req_set_res(req, ret, 0);
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return IOU_COMPLETE;
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}
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int io_epoll_wait_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
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{
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struct io_epoll_wait *iew = io_kiocb_to_cmd(req, struct io_epoll_wait);
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if (sqe->off || sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in)
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return -EINVAL;
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iew->maxevents = READ_ONCE(sqe->len);
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iew->events = u64_to_user_ptr(READ_ONCE(sqe->addr));
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return 0;
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}
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int io_epoll_wait(struct io_kiocb *req, unsigned int issue_flags)
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{
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struct io_epoll_wait *iew = io_kiocb_to_cmd(req, struct io_epoll_wait);
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int ret;
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ret = epoll_sendevents(req->file, iew->events, iew->maxevents);
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if (ret == 0)
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return -EAGAIN;
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if (ret < 0)
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req_set_fail(req);
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io_req_set_res(req, ret, 0);
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return IOU_COMPLETE;
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}
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