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7aaff708 JA |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #include <linux/kernel.h> | |
3 | #include <linux/errno.h> | |
4 | #include <linux/fs.h> | |
5 | #include <linux/file.h> | |
6 | #include <linux/mm.h> | |
7 | #include <linux/slab.h> | |
8 | #include <linux/namei.h> | |
78a861b9 | 9 | #include <linux/nospec.h> |
7aaff708 JA |
10 | #include <linux/io_uring.h> |
11 | ||
12 | #include <uapi/linux/io_uring.h> | |
13 | ||
7aaff708 JA |
14 | #include "io_uring.h" |
15 | #include "tctx.h" | |
16 | #include "poll.h" | |
17 | #include "timeout.h" | |
18 | #include "cancel.h" | |
19 | ||
20 | struct io_cancel { | |
21 | struct file *file; | |
22 | u64 addr; | |
23 | u32 flags; | |
24 | s32 fd; | |
d7b8b079 | 25 | u8 opcode; |
7aaff708 JA |
26 | }; |
27 | ||
28 | #define CANCEL_FLAGS (IORING_ASYNC_CANCEL_ALL | IORING_ASYNC_CANCEL_FD | \ | |
8165b566 | 29 | IORING_ASYNC_CANCEL_ANY | IORING_ASYNC_CANCEL_FD_FIXED | \ |
d7b8b079 | 30 | IORING_ASYNC_CANCEL_USERDATA | IORING_ASYNC_CANCEL_OP) |
7aaff708 | 31 | |
aa5cd116 JA |
32 | /* |
33 | * Returns true if the request matches the criteria outlined by 'cd'. | |
34 | */ | |
35 | bool io_cancel_req_match(struct io_kiocb *req, struct io_cancel_data *cd) | |
7aaff708 | 36 | { |
8165b566 JA |
37 | bool match_user_data = cd->flags & IORING_ASYNC_CANCEL_USERDATA; |
38 | ||
7aaff708 JA |
39 | if (req->ctx != cd->ctx) |
40 | return false; | |
8165b566 | 41 | |
d7b8b079 | 42 | if (!(cd->flags & (IORING_ASYNC_CANCEL_FD | IORING_ASYNC_CANCEL_OP))) |
8165b566 JA |
43 | match_user_data = true; |
44 | ||
45 | if (cd->flags & IORING_ASYNC_CANCEL_ANY) | |
3a372b66 | 46 | goto check_seq; |
8165b566 | 47 | if (cd->flags & IORING_ASYNC_CANCEL_FD) { |
7aaff708 JA |
48 | if (req->file != cd->file) |
49 | return false; | |
7aaff708 | 50 | } |
d7b8b079 JA |
51 | if (cd->flags & IORING_ASYNC_CANCEL_OP) { |
52 | if (req->opcode != cd->opcode) | |
53 | return false; | |
54 | } | |
8165b566 JA |
55 | if (match_user_data && req->cqe.user_data != cd->data) |
56 | return false; | |
3a372b66 JA |
57 | if (cd->flags & IORING_ASYNC_CANCEL_ALL) { |
58 | check_seq: | |
7aaff708 JA |
59 | if (cd->seq == req->work.cancel_seq) |
60 | return false; | |
61 | req->work.cancel_seq = cd->seq; | |
62 | } | |
aa5cd116 | 63 | |
7aaff708 JA |
64 | return true; |
65 | } | |
66 | ||
aa5cd116 JA |
67 | static bool io_cancel_cb(struct io_wq_work *work, void *data) |
68 | { | |
69 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); | |
70 | struct io_cancel_data *cd = data; | |
71 | ||
72 | return io_cancel_req_match(req, cd); | |
73 | } | |
74 | ||
7aaff708 JA |
75 | static int io_async_cancel_one(struct io_uring_task *tctx, |
76 | struct io_cancel_data *cd) | |
77 | { | |
78 | enum io_wq_cancel cancel_ret; | |
79 | int ret = 0; | |
80 | bool all; | |
81 | ||
82 | if (!tctx || !tctx->io_wq) | |
83 | return -ENOENT; | |
84 | ||
85 | all = cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY); | |
86 | cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, cd, all); | |
87 | switch (cancel_ret) { | |
88 | case IO_WQ_CANCEL_OK: | |
89 | ret = 0; | |
90 | break; | |
91 | case IO_WQ_CANCEL_RUNNING: | |
92 | ret = -EALREADY; | |
93 | break; | |
94 | case IO_WQ_CANCEL_NOTFOUND: | |
95 | ret = -ENOENT; | |
96 | break; | |
97 | } | |
98 | ||
99 | return ret; | |
100 | } | |
101 | ||
88f52eaa | 102 | int io_try_cancel(struct io_uring_task *tctx, struct io_cancel_data *cd, |
5d7943d9 | 103 | unsigned issue_flags) |
7aaff708 | 104 | { |
88f52eaa | 105 | struct io_ring_ctx *ctx = cd->ctx; |
7aaff708 JA |
106 | int ret; |
107 | ||
88f52eaa | 108 | WARN_ON_ONCE(!io_wq_current_is_worker() && tctx != current->io_uring); |
7aaff708 | 109 | |
88f52eaa | 110 | ret = io_async_cancel_one(tctx, cd); |
7aaff708 JA |
111 | /* |
112 | * Fall-through even for -EALREADY, as we may have poll armed | |
113 | * that need unarming. | |
114 | */ | |
115 | if (!ret) | |
116 | return 0; | |
117 | ||
5d7943d9 | 118 | ret = io_poll_cancel(ctx, cd, issue_flags); |
7aaff708 | 119 | if (ret != -ENOENT) |
4dfab8ab PB |
120 | return ret; |
121 | ||
38513c46 | 122 | spin_lock(&ctx->completion_lock); |
7aaff708 JA |
123 | if (!(cd->flags & IORING_ASYNC_CANCEL_FD)) |
124 | ret = io_timeout_cancel(ctx, cd); | |
7aaff708 JA |
125 | spin_unlock(&ctx->completion_lock); |
126 | return ret; | |
127 | } | |
128 | ||
7aaff708 JA |
129 | int io_async_cancel_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
130 | { | |
f2ccb5ae | 131 | struct io_cancel *cancel = io_kiocb_to_cmd(req, struct io_cancel); |
7aaff708 JA |
132 | |
133 | if (unlikely(req->flags & REQ_F_BUFFER_SELECT)) | |
134 | return -EINVAL; | |
d7b8b079 | 135 | if (sqe->off || sqe->splice_fd_in) |
7aaff708 JA |
136 | return -EINVAL; |
137 | ||
138 | cancel->addr = READ_ONCE(sqe->addr); | |
139 | cancel->flags = READ_ONCE(sqe->cancel_flags); | |
140 | if (cancel->flags & ~CANCEL_FLAGS) | |
141 | return -EINVAL; | |
142 | if (cancel->flags & IORING_ASYNC_CANCEL_FD) { | |
143 | if (cancel->flags & IORING_ASYNC_CANCEL_ANY) | |
144 | return -EINVAL; | |
145 | cancel->fd = READ_ONCE(sqe->fd); | |
146 | } | |
d7b8b079 JA |
147 | if (cancel->flags & IORING_ASYNC_CANCEL_OP) { |
148 | if (cancel->flags & IORING_ASYNC_CANCEL_ANY) | |
149 | return -EINVAL; | |
150 | cancel->opcode = READ_ONCE(sqe->len); | |
151 | } | |
7aaff708 JA |
152 | |
153 | return 0; | |
154 | } | |
155 | ||
88f52eaa JA |
156 | static int __io_async_cancel(struct io_cancel_data *cd, |
157 | struct io_uring_task *tctx, | |
7aaff708 JA |
158 | unsigned int issue_flags) |
159 | { | |
160 | bool all = cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY); | |
161 | struct io_ring_ctx *ctx = cd->ctx; | |
162 | struct io_tctx_node *node; | |
163 | int ret, nr = 0; | |
164 | ||
165 | do { | |
88f52eaa | 166 | ret = io_try_cancel(tctx, cd, issue_flags); |
7aaff708 JA |
167 | if (ret == -ENOENT) |
168 | break; | |
169 | if (!all) | |
170 | return ret; | |
171 | nr++; | |
172 | } while (1); | |
173 | ||
174 | /* slow path, try all io-wq's */ | |
175 | io_ring_submit_lock(ctx, issue_flags); | |
176 | ret = -ENOENT; | |
177 | list_for_each_entry(node, &ctx->tctx_list, ctx_node) { | |
178 | struct io_uring_task *tctx = node->task->io_uring; | |
179 | ||
180 | ret = io_async_cancel_one(tctx, cd); | |
181 | if (ret != -ENOENT) { | |
182 | if (!all) | |
183 | break; | |
184 | nr++; | |
185 | } | |
186 | } | |
187 | io_ring_submit_unlock(ctx, issue_flags); | |
188 | return all ? nr : ret; | |
189 | } | |
190 | ||
191 | int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags) | |
192 | { | |
f2ccb5ae | 193 | struct io_cancel *cancel = io_kiocb_to_cmd(req, struct io_cancel); |
7aaff708 JA |
194 | struct io_cancel_data cd = { |
195 | .ctx = req->ctx, | |
196 | .data = cancel->addr, | |
197 | .flags = cancel->flags, | |
d7b8b079 | 198 | .opcode = cancel->opcode, |
7aaff708 JA |
199 | .seq = atomic_inc_return(&req->ctx->cancel_seq), |
200 | }; | |
88f52eaa | 201 | struct io_uring_task *tctx = req->task->io_uring; |
7aaff708 JA |
202 | int ret; |
203 | ||
204 | if (cd.flags & IORING_ASYNC_CANCEL_FD) { | |
7d8ca725 JA |
205 | if (req->flags & REQ_F_FIXED_FILE || |
206 | cd.flags & IORING_ASYNC_CANCEL_FD_FIXED) { | |
207 | req->flags |= REQ_F_FIXED_FILE; | |
7aaff708 JA |
208 | req->file = io_file_get_fixed(req, cancel->fd, |
209 | issue_flags); | |
7d8ca725 | 210 | } else { |
7aaff708 | 211 | req->file = io_file_get_normal(req, cancel->fd); |
7d8ca725 | 212 | } |
7aaff708 JA |
213 | if (!req->file) { |
214 | ret = -EBADF; | |
215 | goto done; | |
216 | } | |
217 | cd.file = req->file; | |
218 | } | |
219 | ||
88f52eaa | 220 | ret = __io_async_cancel(&cd, tctx, issue_flags); |
7aaff708 JA |
221 | done: |
222 | if (ret < 0) | |
223 | req_set_fail(req); | |
224 | io_req_set_res(req, ret, 0); | |
225 | return IOU_OK; | |
226 | } | |
38513c46 | 227 | |
e6f89be6 | 228 | void init_hash_table(struct io_hash_table *table, unsigned size) |
38513c46 HX |
229 | { |
230 | unsigned int i; | |
231 | ||
232 | for (i = 0; i < size; i++) { | |
e6f89be6 PB |
233 | spin_lock_init(&table->hbs[i].lock); |
234 | INIT_HLIST_HEAD(&table->hbs[i].list); | |
38513c46 HX |
235 | } |
236 | } | |
78a861b9 JA |
237 | |
238 | static int __io_sync_cancel(struct io_uring_task *tctx, | |
239 | struct io_cancel_data *cd, int fd) | |
240 | { | |
241 | struct io_ring_ctx *ctx = cd->ctx; | |
242 | ||
243 | /* fixed must be grabbed every time since we drop the uring_lock */ | |
244 | if ((cd->flags & IORING_ASYNC_CANCEL_FD) && | |
245 | (cd->flags & IORING_ASYNC_CANCEL_FD_FIXED)) { | |
47abea04 | 246 | if (unlikely(fd >= ctx->nr_user_files)) |
78a861b9 JA |
247 | return -EBADF; |
248 | fd = array_index_nospec(fd, ctx->nr_user_files); | |
60a666f0 | 249 | cd->file = io_file_from_index(&ctx->file_table, fd); |
78a861b9 JA |
250 | if (!cd->file) |
251 | return -EBADF; | |
252 | } | |
253 | ||
254 | return __io_async_cancel(cd, tctx, 0); | |
255 | } | |
256 | ||
257 | int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg) | |
258 | __must_hold(&ctx->uring_lock) | |
259 | { | |
260 | struct io_cancel_data cd = { | |
261 | .ctx = ctx, | |
262 | .seq = atomic_inc_return(&ctx->cancel_seq), | |
263 | }; | |
264 | ktime_t timeout = KTIME_MAX; | |
265 | struct io_uring_sync_cancel_reg sc; | |
266 | struct fd f = { }; | |
267 | DEFINE_WAIT(wait); | |
268 | int ret; | |
269 | ||
270 | if (copy_from_user(&sc, arg, sizeof(sc))) | |
271 | return -EFAULT; | |
272 | if (sc.flags & ~CANCEL_FLAGS) | |
273 | return -EINVAL; | |
274 | if (sc.pad[0] || sc.pad[1] || sc.pad[2] || sc.pad[3]) | |
275 | return -EINVAL; | |
276 | ||
277 | cd.data = sc.addr; | |
278 | cd.flags = sc.flags; | |
279 | ||
280 | /* we can grab a normal file descriptor upfront */ | |
281 | if ((cd.flags & IORING_ASYNC_CANCEL_FD) && | |
282 | !(cd.flags & IORING_ASYNC_CANCEL_FD_FIXED)) { | |
283 | f = fdget(sc.fd); | |
284 | if (!f.file) | |
285 | return -EBADF; | |
286 | cd.file = f.file; | |
287 | } | |
288 | ||
289 | ret = __io_sync_cancel(current->io_uring, &cd, sc.fd); | |
290 | ||
291 | /* found something, done! */ | |
292 | if (ret != -EALREADY) | |
293 | goto out; | |
294 | ||
295 | if (sc.timeout.tv_sec != -1UL || sc.timeout.tv_nsec != -1UL) { | |
296 | struct timespec64 ts = { | |
297 | .tv_sec = sc.timeout.tv_sec, | |
298 | .tv_nsec = sc.timeout.tv_nsec | |
299 | }; | |
300 | ||
301 | timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns()); | |
302 | } | |
303 | ||
304 | /* | |
305 | * Keep looking until we get -ENOENT. we'll get woken everytime | |
306 | * every time a request completes and will retry the cancelation. | |
307 | */ | |
308 | do { | |
309 | cd.seq = atomic_inc_return(&ctx->cancel_seq); | |
310 | ||
311 | prepare_to_wait(&ctx->cq_wait, &wait, TASK_INTERRUPTIBLE); | |
312 | ||
313 | ret = __io_sync_cancel(current->io_uring, &cd, sc.fd); | |
314 | ||
23fffb2f | 315 | mutex_unlock(&ctx->uring_lock); |
78a861b9 JA |
316 | if (ret != -EALREADY) |
317 | break; | |
318 | ||
c0e0d6ba | 319 | ret = io_run_task_work_sig(ctx); |
23fffb2f | 320 | if (ret < 0) |
78a861b9 | 321 | break; |
78a861b9 | 322 | ret = schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS); |
78a861b9 JA |
323 | if (!ret) { |
324 | ret = -ETIME; | |
325 | break; | |
326 | } | |
23fffb2f | 327 | mutex_lock(&ctx->uring_lock); |
78a861b9 JA |
328 | } while (1); |
329 | ||
330 | finish_wait(&ctx->cq_wait, &wait); | |
23fffb2f | 331 | mutex_lock(&ctx->uring_lock); |
78a861b9 JA |
332 | |
333 | if (ret == -ENOENT || ret > 0) | |
334 | ret = 0; | |
335 | out: | |
336 | fdput(f); | |
337 | return ret; | |
338 | } |