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/slab.h>
6 #include <linux/nospec.h>
7 #include <linux/io_uring.h>
9 #include <uapi/linux/io_uring.h>
13 #include "filetable.h"
18 struct file *src_file;
27 static void io_double_unlock_ctx(struct io_ring_ctx *octx)
29 mutex_unlock(&octx->uring_lock);
32 static int io_double_lock_ctx(struct io_ring_ctx *octx,
33 unsigned int issue_flags)
36 * To ensure proper ordering between the two ctxs, we can only
37 * attempt a trylock on the target. If that fails and we already have
38 * the source ctx lock, punt to io-wq.
40 if (!(issue_flags & IO_URING_F_UNLOCKED)) {
41 if (!mutex_trylock(&octx->uring_lock))
45 mutex_lock(&octx->uring_lock);
49 void io_msg_ring_cleanup(struct io_kiocb *req)
51 struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);
53 if (WARN_ON_ONCE(!msg->src_file))
60 static int io_msg_ring_data(struct io_kiocb *req)
62 struct io_ring_ctx *target_ctx = req->file->private_data;
63 struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);
65 if (msg->src_fd || msg->dst_fd || msg->flags)
67 if (target_ctx->flags & IORING_SETUP_R_DISABLED)
70 if (io_post_aux_cqe(target_ctx, msg->user_data, msg->len, 0, true))
76 static struct file *io_msg_grab_file(struct io_kiocb *req, unsigned int issue_flags)
78 struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);
79 struct io_ring_ctx *ctx = req->ctx;
80 struct file *file = NULL;
81 unsigned long file_ptr;
82 int idx = msg->src_fd;
84 io_ring_submit_lock(ctx, issue_flags);
85 if (likely(idx < ctx->nr_user_files)) {
86 idx = array_index_nospec(idx, ctx->nr_user_files);
87 file_ptr = io_fixed_file_slot(&ctx->file_table, idx)->file_ptr;
88 file = (struct file *) (file_ptr & FFS_MASK);
92 io_ring_submit_unlock(ctx, issue_flags);
96 static int io_msg_install_complete(struct io_kiocb *req, unsigned int issue_flags)
98 struct io_ring_ctx *target_ctx = req->file->private_data;
99 struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);
100 struct file *src_file = msg->src_file;
103 if (unlikely(io_double_lock_ctx(target_ctx, issue_flags)))
106 ret = __io_fixed_fd_install(target_ctx, src_file, msg->dst_fd);
110 msg->src_file = NULL;
111 req->flags &= ~REQ_F_NEED_CLEANUP;
113 if (msg->flags & IORING_MSG_RING_CQE_SKIP)
116 * If this fails, the target still received the file descriptor but
117 * wasn't notified of the fact. This means that if this request
118 * completes with -EOVERFLOW, then the sender must ensure that a
119 * later IORING_OP_MSG_RING delivers the message.
121 if (!io_post_aux_cqe(target_ctx, msg->user_data, ret, 0, true))
124 io_double_unlock_ctx(target_ctx);
128 static int io_msg_send_fd(struct io_kiocb *req, unsigned int issue_flags)
130 struct io_ring_ctx *target_ctx = req->file->private_data;
131 struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);
132 struct io_ring_ctx *ctx = req->ctx;
133 struct file *src_file = msg->src_file;
135 if (target_ctx == ctx)
138 src_file = io_msg_grab_file(req, issue_flags);
141 msg->src_file = src_file;
142 req->flags |= REQ_F_NEED_CLEANUP;
144 return io_msg_install_complete(req, issue_flags);
147 int io_msg_ring_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
149 struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);
151 if (unlikely(sqe->buf_index || sqe->personality))
154 msg->src_file = NULL;
155 msg->user_data = READ_ONCE(sqe->off);
156 msg->len = READ_ONCE(sqe->len);
157 msg->cmd = READ_ONCE(sqe->addr);
158 msg->src_fd = READ_ONCE(sqe->addr3);
159 msg->dst_fd = READ_ONCE(sqe->file_index);
160 msg->flags = READ_ONCE(sqe->msg_ring_flags);
161 if (msg->flags & ~IORING_MSG_RING_CQE_SKIP)
167 int io_msg_ring(struct io_kiocb *req, unsigned int issue_flags)
169 struct io_msg *msg = io_kiocb_to_cmd(req, struct io_msg);
173 if (!io_is_uring_fops(req->file))
177 case IORING_MSG_DATA:
178 ret = io_msg_ring_data(req);
180 case IORING_MSG_SEND_FD:
181 ret = io_msg_send_fd(req, issue_flags);
193 io_req_set_res(req, ret, 0);