xref: /linux/io_uring/uring_cmd.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
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/io_uring/cmd.h>
6 #include <linux/io_uring/net.h>
7 #include <linux/security.h>
8 #include <linux/nospec.h>
9 #include <net/sock.h>
10 
11 #include <uapi/linux/io_uring.h>
12 #include <asm/ioctls.h>
13 
14 #include "io_uring.h"
15 #include "alloc_cache.h"
16 #include "rsrc.h"
17 #include "uring_cmd.h"
18 
19 static struct uring_cache *io_uring_async_get(struct io_kiocb *req)
20 {
21 	struct io_ring_ctx *ctx = req->ctx;
22 	struct uring_cache *cache;
23 
24 	cache = io_alloc_cache_get(&ctx->uring_cache);
25 	if (cache) {
26 		req->flags |= REQ_F_ASYNC_DATA;
27 		req->async_data = cache;
28 		return cache;
29 	}
30 	if (!io_alloc_async_data(req))
31 		return req->async_data;
32 	return NULL;
33 }
34 
35 static void io_req_uring_cleanup(struct io_kiocb *req, unsigned int issue_flags)
36 {
37 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
38 	struct uring_cache *cache = req->async_data;
39 
40 	if (issue_flags & IO_URING_F_UNLOCKED)
41 		return;
42 	if (io_alloc_cache_put(&req->ctx->uring_cache, cache)) {
43 		ioucmd->sqe = NULL;
44 		req->async_data = NULL;
45 		req->flags &= ~REQ_F_ASYNC_DATA;
46 	}
47 }
48 
49 bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx,
50 				   struct task_struct *task, bool cancel_all)
51 {
52 	struct hlist_node *tmp;
53 	struct io_kiocb *req;
54 	bool ret = false;
55 
56 	lockdep_assert_held(&ctx->uring_lock);
57 
58 	hlist_for_each_entry_safe(req, tmp, &ctx->cancelable_uring_cmd,
59 			hash_node) {
60 		struct io_uring_cmd *cmd = io_kiocb_to_cmd(req,
61 				struct io_uring_cmd);
62 		struct file *file = req->file;
63 
64 		if (!cancel_all && req->task != task)
65 			continue;
66 
67 		if (cmd->flags & IORING_URING_CMD_CANCELABLE) {
68 			/* ->sqe isn't available if no async data */
69 			if (!req_has_async_data(req))
70 				cmd->sqe = NULL;
71 			file->f_op->uring_cmd(cmd, IO_URING_F_CANCEL |
72 						   IO_URING_F_COMPLETE_DEFER);
73 			ret = true;
74 		}
75 	}
76 	io_submit_flush_completions(ctx);
77 	return ret;
78 }
79 
80 static void io_uring_cmd_del_cancelable(struct io_uring_cmd *cmd,
81 		unsigned int issue_flags)
82 {
83 	struct io_kiocb *req = cmd_to_io_kiocb(cmd);
84 	struct io_ring_ctx *ctx = req->ctx;
85 
86 	if (!(cmd->flags & IORING_URING_CMD_CANCELABLE))
87 		return;
88 
89 	cmd->flags &= ~IORING_URING_CMD_CANCELABLE;
90 	io_ring_submit_lock(ctx, issue_flags);
91 	hlist_del(&req->hash_node);
92 	io_ring_submit_unlock(ctx, issue_flags);
93 }
94 
95 /*
96  * Mark this command as concelable, then io_uring_try_cancel_uring_cmd()
97  * will try to cancel this issued command by sending ->uring_cmd() with
98  * issue_flags of IO_URING_F_CANCEL.
99  *
100  * The command is guaranteed to not be done when calling ->uring_cmd()
101  * with IO_URING_F_CANCEL, but it is driver's responsibility to deal
102  * with race between io_uring canceling and normal completion.
103  */
104 void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
105 		unsigned int issue_flags)
106 {
107 	struct io_kiocb *req = cmd_to_io_kiocb(cmd);
108 	struct io_ring_ctx *ctx = req->ctx;
109 
110 	if (!(cmd->flags & IORING_URING_CMD_CANCELABLE)) {
111 		cmd->flags |= IORING_URING_CMD_CANCELABLE;
112 		io_ring_submit_lock(ctx, issue_flags);
113 		hlist_add_head(&req->hash_node, &ctx->cancelable_uring_cmd);
114 		io_ring_submit_unlock(ctx, issue_flags);
115 	}
116 }
117 EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable);
118 
119 static void io_uring_cmd_work(struct io_kiocb *req, struct io_tw_state *ts)
120 {
121 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
122 
123 	/* task_work executor checks the deffered list completion */
124 	ioucmd->task_work_cb(ioucmd, IO_URING_F_COMPLETE_DEFER);
125 }
126 
127 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
128 			void (*task_work_cb)(struct io_uring_cmd *, unsigned),
129 			unsigned flags)
130 {
131 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
132 
133 	ioucmd->task_work_cb = task_work_cb;
134 	req->io_task_work.func = io_uring_cmd_work;
135 	__io_req_task_work_add(req, flags);
136 }
137 EXPORT_SYMBOL_GPL(__io_uring_cmd_do_in_task);
138 
139 static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
140 					  u64 extra1, u64 extra2)
141 {
142 	req->big_cqe.extra1 = extra1;
143 	req->big_cqe.extra2 = extra2;
144 }
145 
146 /*
147  * Called by consumers of io_uring_cmd, if they originally returned
148  * -EIOCBQUEUED upon receiving the command.
149  */
150 void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2,
151 		       unsigned issue_flags)
152 {
153 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
154 
155 	io_uring_cmd_del_cancelable(ioucmd, issue_flags);
156 
157 	if (ret < 0)
158 		req_set_fail(req);
159 
160 	io_req_set_res(req, ret, 0);
161 	if (req->ctx->flags & IORING_SETUP_CQE32)
162 		io_req_set_cqe32_extra(req, res2, 0);
163 	io_req_uring_cleanup(req, issue_flags);
164 	if (req->ctx->flags & IORING_SETUP_IOPOLL) {
165 		/* order with io_iopoll_req_issued() checking ->iopoll_complete */
166 		smp_store_release(&req->iopoll_completed, 1);
167 	} else if (issue_flags & IO_URING_F_COMPLETE_DEFER) {
168 		if (WARN_ON_ONCE(issue_flags & IO_URING_F_UNLOCKED))
169 			return;
170 		io_req_complete_defer(req);
171 	} else {
172 		req->io_task_work.func = io_req_task_complete;
173 		io_req_task_work_add(req);
174 	}
175 }
176 EXPORT_SYMBOL_GPL(io_uring_cmd_done);
177 
178 static int io_uring_cmd_prep_setup(struct io_kiocb *req,
179 				   const struct io_uring_sqe *sqe)
180 {
181 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
182 	struct uring_cache *cache;
183 
184 	cache = io_uring_async_get(req);
185 	if (unlikely(!cache))
186 		return -ENOMEM;
187 
188 	if (!(req->flags & REQ_F_FORCE_ASYNC)) {
189 		/* defer memcpy until we need it */
190 		ioucmd->sqe = sqe;
191 		return 0;
192 	}
193 
194 	memcpy(req->async_data, sqe, uring_sqe_size(req->ctx));
195 	ioucmd->sqe = req->async_data;
196 	return 0;
197 }
198 
199 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
200 {
201 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
202 
203 	if (sqe->__pad1)
204 		return -EINVAL;
205 
206 	ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
207 	if (ioucmd->flags & ~IORING_URING_CMD_MASK)
208 		return -EINVAL;
209 
210 	if (ioucmd->flags & IORING_URING_CMD_FIXED) {
211 		struct io_ring_ctx *ctx = req->ctx;
212 		u16 index;
213 
214 		req->buf_index = READ_ONCE(sqe->buf_index);
215 		if (unlikely(req->buf_index >= ctx->nr_user_bufs))
216 			return -EFAULT;
217 		index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
218 		req->imu = ctx->user_bufs[index];
219 		io_req_set_rsrc_node(req, ctx, 0);
220 	}
221 	ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
222 
223 	return io_uring_cmd_prep_setup(req, sqe);
224 }
225 
226 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
227 {
228 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
229 	struct io_ring_ctx *ctx = req->ctx;
230 	struct file *file = req->file;
231 	int ret;
232 
233 	if (!file->f_op->uring_cmd)
234 		return -EOPNOTSUPP;
235 
236 	ret = security_uring_cmd(ioucmd);
237 	if (ret)
238 		return ret;
239 
240 	if (ctx->flags & IORING_SETUP_SQE128)
241 		issue_flags |= IO_URING_F_SQE128;
242 	if (ctx->flags & IORING_SETUP_CQE32)
243 		issue_flags |= IO_URING_F_CQE32;
244 	if (ctx->compat)
245 		issue_flags |= IO_URING_F_COMPAT;
246 	if (ctx->flags & IORING_SETUP_IOPOLL) {
247 		if (!file->f_op->uring_cmd_iopoll)
248 			return -EOPNOTSUPP;
249 		issue_flags |= IO_URING_F_IOPOLL;
250 		req->iopoll_completed = 0;
251 	}
252 
253 	ret = file->f_op->uring_cmd(ioucmd, issue_flags);
254 	if (ret == -EAGAIN) {
255 		struct uring_cache *cache = req->async_data;
256 
257 		if (ioucmd->sqe != (void *) cache)
258 			memcpy(cache, ioucmd->sqe, uring_sqe_size(req->ctx));
259 		return -EAGAIN;
260 	} else if (ret == -EIOCBQUEUED) {
261 		return -EIOCBQUEUED;
262 	}
263 
264 	if (ret < 0)
265 		req_set_fail(req);
266 	io_req_uring_cleanup(req, issue_flags);
267 	io_req_set_res(req, ret, 0);
268 	return IOU_OK;
269 }
270 
271 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
272 			      struct iov_iter *iter, void *ioucmd)
273 {
274 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
275 
276 	return io_import_fixed(rw, iter, req->imu, ubuf, len);
277 }
278 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
279 
280 static inline int io_uring_cmd_getsockopt(struct socket *sock,
281 					  struct io_uring_cmd *cmd,
282 					  unsigned int issue_flags)
283 {
284 	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
285 	int optlen, optname, level, err;
286 	void __user *optval;
287 
288 	level = READ_ONCE(cmd->sqe->level);
289 	if (level != SOL_SOCKET)
290 		return -EOPNOTSUPP;
291 
292 	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
293 	optname = READ_ONCE(cmd->sqe->optname);
294 	optlen = READ_ONCE(cmd->sqe->optlen);
295 
296 	err = do_sock_getsockopt(sock, compat, level, optname,
297 				 USER_SOCKPTR(optval),
298 				 KERNEL_SOCKPTR(&optlen));
299 	if (err)
300 		return err;
301 
302 	/* On success, return optlen */
303 	return optlen;
304 }
305 
306 static inline int io_uring_cmd_setsockopt(struct socket *sock,
307 					  struct io_uring_cmd *cmd,
308 					  unsigned int issue_flags)
309 {
310 	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
311 	int optname, optlen, level;
312 	void __user *optval;
313 	sockptr_t optval_s;
314 
315 	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
316 	optname = READ_ONCE(cmd->sqe->optname);
317 	optlen = READ_ONCE(cmd->sqe->optlen);
318 	level = READ_ONCE(cmd->sqe->level);
319 	optval_s = USER_SOCKPTR(optval);
320 
321 	return do_sock_setsockopt(sock, compat, level, optname, optval_s,
322 				  optlen);
323 }
324 
325 #if defined(CONFIG_NET)
326 int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
327 {
328 	struct socket *sock = cmd->file->private_data;
329 	struct sock *sk = sock->sk;
330 	struct proto *prot = READ_ONCE(sk->sk_prot);
331 	int ret, arg = 0;
332 
333 	if (!prot || !prot->ioctl)
334 		return -EOPNOTSUPP;
335 
336 	switch (cmd->sqe->cmd_op) {
337 	case SOCKET_URING_OP_SIOCINQ:
338 		ret = prot->ioctl(sk, SIOCINQ, &arg);
339 		if (ret)
340 			return ret;
341 		return arg;
342 	case SOCKET_URING_OP_SIOCOUTQ:
343 		ret = prot->ioctl(sk, SIOCOUTQ, &arg);
344 		if (ret)
345 			return ret;
346 		return arg;
347 	case SOCKET_URING_OP_GETSOCKOPT:
348 		return io_uring_cmd_getsockopt(sock, cmd, issue_flags);
349 	case SOCKET_URING_OP_SETSOCKOPT:
350 		return io_uring_cmd_setsockopt(sock, cmd, issue_flags);
351 	default:
352 		return -EOPNOTSUPP;
353 	}
354 }
355 EXPORT_SYMBOL_GPL(io_uring_cmd_sock);
356 #endif
357