xref: /linux/io_uring/uring_cmd.c (revision dadf03cfd4eaa09f1d0e8b2521de1e11d3e3bec1)
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 io_uring_cmd_data *io_uring_async_get(struct io_kiocb *req)
20 {
21 	struct io_ring_ctx *ctx = req->ctx;
22 	struct io_uring_cmd_data *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 io_uring_cmd_data *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 	unsigned int flags = IO_URING_F_COMPLETE_DEFER;
123 
124 	if (current->flags & (PF_EXITING | PF_KTHREAD))
125 		flags |= IO_URING_F_TASK_DEAD;
126 
127 	/* task_work executor checks the deffered list completion */
128 	ioucmd->task_work_cb(ioucmd, flags);
129 }
130 
131 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
132 			void (*task_work_cb)(struct io_uring_cmd *, unsigned),
133 			unsigned flags)
134 {
135 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
136 
137 	ioucmd->task_work_cb = task_work_cb;
138 	req->io_task_work.func = io_uring_cmd_work;
139 	__io_req_task_work_add(req, flags);
140 }
141 EXPORT_SYMBOL_GPL(__io_uring_cmd_do_in_task);
142 
143 static inline void io_req_set_cqe32_extra(struct io_kiocb *req,
144 					  u64 extra1, u64 extra2)
145 {
146 	req->big_cqe.extra1 = extra1;
147 	req->big_cqe.extra2 = extra2;
148 }
149 
150 /*
151  * Called by consumers of io_uring_cmd, if they originally returned
152  * -EIOCBQUEUED upon receiving the command.
153  */
154 void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2,
155 		       unsigned issue_flags)
156 {
157 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
158 
159 	io_uring_cmd_del_cancelable(ioucmd, issue_flags);
160 
161 	if (ret < 0)
162 		req_set_fail(req);
163 
164 	io_req_set_res(req, ret, 0);
165 	if (req->ctx->flags & IORING_SETUP_CQE32)
166 		io_req_set_cqe32_extra(req, res2, 0);
167 	io_req_uring_cleanup(req, issue_flags);
168 	if (req->ctx->flags & IORING_SETUP_IOPOLL) {
169 		/* order with io_iopoll_req_issued() checking ->iopoll_complete */
170 		smp_store_release(&req->iopoll_completed, 1);
171 	} else if (issue_flags & IO_URING_F_COMPLETE_DEFER) {
172 		if (WARN_ON_ONCE(issue_flags & IO_URING_F_UNLOCKED))
173 			return;
174 		io_req_complete_defer(req);
175 	} else {
176 		req->io_task_work.func = io_req_task_complete;
177 		io_req_task_work_add(req);
178 	}
179 }
180 EXPORT_SYMBOL_GPL(io_uring_cmd_done);
181 
182 static int io_uring_cmd_prep_setup(struct io_kiocb *req,
183 				   const struct io_uring_sqe *sqe)
184 {
185 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
186 	struct io_uring_cmd_data *cache;
187 
188 	cache = io_uring_async_get(req);
189 	if (unlikely(!cache))
190 		return -ENOMEM;
191 
192 	if (!(req->flags & REQ_F_FORCE_ASYNC)) {
193 		/* defer memcpy until we need it */
194 		ioucmd->sqe = sqe;
195 		return 0;
196 	}
197 
198 	memcpy(req->async_data, sqe, uring_sqe_size(req->ctx));
199 	ioucmd->sqe = req->async_data;
200 	return 0;
201 }
202 
203 int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
204 {
205 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
206 
207 	if (sqe->__pad1)
208 		return -EINVAL;
209 
210 	ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);
211 	if (ioucmd->flags & ~IORING_URING_CMD_MASK)
212 		return -EINVAL;
213 
214 	if (ioucmd->flags & IORING_URING_CMD_FIXED) {
215 		struct io_ring_ctx *ctx = req->ctx;
216 		u16 index;
217 
218 		req->buf_index = READ_ONCE(sqe->buf_index);
219 		if (unlikely(req->buf_index >= ctx->nr_user_bufs))
220 			return -EFAULT;
221 		index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
222 		req->imu = ctx->user_bufs[index];
223 		io_req_set_rsrc_node(req, ctx, 0);
224 	}
225 	ioucmd->cmd_op = READ_ONCE(sqe->cmd_op);
226 
227 	return io_uring_cmd_prep_setup(req, sqe);
228 }
229 
230 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
231 {
232 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
233 	struct io_ring_ctx *ctx = req->ctx;
234 	struct file *file = req->file;
235 	int ret;
236 
237 	if (!file->f_op->uring_cmd)
238 		return -EOPNOTSUPP;
239 
240 	ret = security_uring_cmd(ioucmd);
241 	if (ret)
242 		return ret;
243 
244 	if (ctx->flags & IORING_SETUP_SQE128)
245 		issue_flags |= IO_URING_F_SQE128;
246 	if (ctx->flags & IORING_SETUP_CQE32)
247 		issue_flags |= IO_URING_F_CQE32;
248 	if (ctx->compat)
249 		issue_flags |= IO_URING_F_COMPAT;
250 	if (ctx->flags & IORING_SETUP_IOPOLL) {
251 		if (!file->f_op->uring_cmd_iopoll)
252 			return -EOPNOTSUPP;
253 		issue_flags |= IO_URING_F_IOPOLL;
254 		req->iopoll_completed = 0;
255 	}
256 
257 	ret = file->f_op->uring_cmd(ioucmd, issue_flags);
258 	if (ret == -EAGAIN) {
259 		struct io_uring_cmd_data *cache = req->async_data;
260 
261 		if (ioucmd->sqe != (void *) cache)
262 			memcpy(cache, ioucmd->sqe, uring_sqe_size(req->ctx));
263 		return -EAGAIN;
264 	} else if (ret == -EIOCBQUEUED) {
265 		return -EIOCBQUEUED;
266 	}
267 
268 	if (ret < 0)
269 		req_set_fail(req);
270 	io_req_uring_cleanup(req, issue_flags);
271 	io_req_set_res(req, ret, 0);
272 	return IOU_OK;
273 }
274 
275 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
276 			      struct iov_iter *iter, void *ioucmd)
277 {
278 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
279 
280 	return io_import_fixed(rw, iter, req->imu, ubuf, len);
281 }
282 EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
283 
284 void io_uring_cmd_issue_blocking(struct io_uring_cmd *ioucmd)
285 {
286 	struct io_kiocb *req = cmd_to_io_kiocb(ioucmd);
287 
288 	io_req_queue_iowq(req);
289 }
290 
291 static inline int io_uring_cmd_getsockopt(struct socket *sock,
292 					  struct io_uring_cmd *cmd,
293 					  unsigned int issue_flags)
294 {
295 	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
296 	int optlen, optname, level, err;
297 	void __user *optval;
298 
299 	level = READ_ONCE(cmd->sqe->level);
300 	if (level != SOL_SOCKET)
301 		return -EOPNOTSUPP;
302 
303 	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
304 	optname = READ_ONCE(cmd->sqe->optname);
305 	optlen = READ_ONCE(cmd->sqe->optlen);
306 
307 	err = do_sock_getsockopt(sock, compat, level, optname,
308 				 USER_SOCKPTR(optval),
309 				 KERNEL_SOCKPTR(&optlen));
310 	if (err)
311 		return err;
312 
313 	/* On success, return optlen */
314 	return optlen;
315 }
316 
317 static inline int io_uring_cmd_setsockopt(struct socket *sock,
318 					  struct io_uring_cmd *cmd,
319 					  unsigned int issue_flags)
320 {
321 	bool compat = !!(issue_flags & IO_URING_F_COMPAT);
322 	int optname, optlen, level;
323 	void __user *optval;
324 	sockptr_t optval_s;
325 
326 	optval = u64_to_user_ptr(READ_ONCE(cmd->sqe->optval));
327 	optname = READ_ONCE(cmd->sqe->optname);
328 	optlen = READ_ONCE(cmd->sqe->optlen);
329 	level = READ_ONCE(cmd->sqe->level);
330 	optval_s = USER_SOCKPTR(optval);
331 
332 	return do_sock_setsockopt(sock, compat, level, optname, optval_s,
333 				  optlen);
334 }
335 
336 #if defined(CONFIG_NET)
337 int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
338 {
339 	struct socket *sock = cmd->file->private_data;
340 	struct sock *sk = sock->sk;
341 	struct proto *prot = READ_ONCE(sk->sk_prot);
342 	int ret, arg = 0;
343 
344 	if (!prot || !prot->ioctl)
345 		return -EOPNOTSUPP;
346 
347 	switch (cmd->sqe->cmd_op) {
348 	case SOCKET_URING_OP_SIOCINQ:
349 		ret = prot->ioctl(sk, SIOCINQ, &arg);
350 		if (ret)
351 			return ret;
352 		return arg;
353 	case SOCKET_URING_OP_SIOCOUTQ:
354 		ret = prot->ioctl(sk, SIOCOUTQ, &arg);
355 		if (ret)
356 			return ret;
357 		return arg;
358 	case SOCKET_URING_OP_GETSOCKOPT:
359 		return io_uring_cmd_getsockopt(sock, cmd, issue_flags);
360 	case SOCKET_URING_OP_SETSOCKOPT:
361 		return io_uring_cmd_setsockopt(sock, cmd, issue_flags);
362 	default:
363 		return -EOPNOTSUPP;
364 	}
365 }
366 EXPORT_SYMBOL_GPL(io_uring_cmd_sock);
367 #endif
368