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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/io_uring.h>
7
8#include <uapi/linux/io_uring.h>
9
10#include "../kernel/futex/futex.h"
11#include "io_uring.h"
12#include "rsrc.h"
13#include "futex.h"
14
15struct io_futex {
16 struct file *file;
17 union {
18 u32 __user *uaddr;
19 struct futex_waitv __user *uwaitv;
20 };
21 unsigned long futex_val;
22 unsigned long futex_mask;
23 unsigned long futexv_owned;
24 u32 futex_flags;
25 unsigned int futex_nr;
26 bool futexv_unqueued;
27};
28
29struct io_futex_data {
30 union {
31 struct futex_q q;
32 struct io_cache_entry cache;
33 };
34 struct io_kiocb *req;
35};
36
37void io_futex_cache_init(struct io_ring_ctx *ctx)
38{
39 io_alloc_cache_init(&ctx->futex_cache, IO_NODE_ALLOC_CACHE_MAX,
40 sizeof(struct io_futex_data));
41}
42
43static void io_futex_cache_entry_free(struct io_cache_entry *entry)
44{
45 kfree(container_of(entry, struct io_futex_data, cache));
46}
47
48void io_futex_cache_free(struct io_ring_ctx *ctx)
49{
50 io_alloc_cache_free(&ctx->futex_cache, io_futex_cache_entry_free);
51}
52
53static void __io_futex_complete(struct io_kiocb *req, struct io_tw_state *ts)
54{
55 req->async_data = NULL;
56 hlist_del_init(&req->hash_node);
57 io_req_task_complete(req, ts);
58}
59
60static void io_futex_complete(struct io_kiocb *req, struct io_tw_state *ts)
61{
62 struct io_futex_data *ifd = req->async_data;
63 struct io_ring_ctx *ctx = req->ctx;
64
65 io_tw_lock(ctx, ts);
66 if (!io_alloc_cache_put(&ctx->futex_cache, &ifd->cache))
67 kfree(ifd);
68 __io_futex_complete(req, ts);
69}
70
71static void io_futexv_complete(struct io_kiocb *req, struct io_tw_state *ts)
72{
73 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
74 struct futex_vector *futexv = req->async_data;
75
76 io_tw_lock(req->ctx, ts);
77
78 if (!iof->futexv_unqueued) {
79 int res;
80
81 res = futex_unqueue_multiple(futexv, iof->futex_nr);
82 if (res != -1)
83 io_req_set_res(req, res, 0);
84 }
85
86 kfree(req->async_data);
87 req->flags &= ~REQ_F_ASYNC_DATA;
88 __io_futex_complete(req, ts);
89}
90
91static bool io_futexv_claim(struct io_futex *iof)
92{
93 if (test_bit(0, &iof->futexv_owned) ||
94 test_and_set_bit_lock(0, &iof->futexv_owned))
95 return false;
96 return true;
97}
98
99static bool __io_futex_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req)
100{
101 /* futex wake already done or in progress */
102 if (req->opcode == IORING_OP_FUTEX_WAIT) {
103 struct io_futex_data *ifd = req->async_data;
104
105 if (!futex_unqueue(&ifd->q))
106 return false;
107 req->io_task_work.func = io_futex_complete;
108 } else {
109 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
110
111 if (!io_futexv_claim(iof))
112 return false;
113 req->io_task_work.func = io_futexv_complete;
114 }
115
116 hlist_del_init(&req->hash_node);
117 io_req_set_res(req, -ECANCELED, 0);
118 io_req_task_work_add(req);
119 return true;
120}
121
122int io_futex_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
123 unsigned int issue_flags)
124{
125 struct hlist_node *tmp;
126 struct io_kiocb *req;
127 int nr = 0;
128
129 if (cd->flags & (IORING_ASYNC_CANCEL_FD|IORING_ASYNC_CANCEL_FD_FIXED))
130 return -ENOENT;
131
132 io_ring_submit_lock(ctx, issue_flags);
133 hlist_for_each_entry_safe(req, tmp, &ctx->futex_list, hash_node) {
134 if (req->cqe.user_data != cd->data &&
135 !(cd->flags & IORING_ASYNC_CANCEL_ANY))
136 continue;
137 if (__io_futex_cancel(ctx, req))
138 nr++;
139 if (!(cd->flags & IORING_ASYNC_CANCEL_ALL))
140 break;
141 }
142 io_ring_submit_unlock(ctx, issue_flags);
143
144 if (nr)
145 return nr;
146
147 return -ENOENT;
148}
149
150bool io_futex_remove_all(struct io_ring_ctx *ctx, struct task_struct *task,
151 bool cancel_all)
152{
153 struct hlist_node *tmp;
154 struct io_kiocb *req;
155 bool found = false;
156
157 lockdep_assert_held(&ctx->uring_lock);
158
159 hlist_for_each_entry_safe(req, tmp, &ctx->futex_list, hash_node) {
160 if (!io_match_task_safe(req, task, cancel_all))
161 continue;
162 hlist_del_init(&req->hash_node);
163 __io_futex_cancel(ctx, req);
164 found = true;
165 }
166
167 return found;
168}
169
170int io_futex_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
171{
172 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
173 u32 flags;
174
175 if (unlikely(sqe->len || sqe->futex_flags || sqe->buf_index ||
176 sqe->file_index))
177 return -EINVAL;
178
179 iof->uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
180 iof->futex_val = READ_ONCE(sqe->addr2);
181 iof->futex_mask = READ_ONCE(sqe->addr3);
182 flags = READ_ONCE(sqe->fd);
183
184 if (flags & ~FUTEX2_VALID_MASK)
185 return -EINVAL;
186
187 iof->futex_flags = futex2_to_flags(flags);
188 if (!futex_flags_valid(iof->futex_flags))
189 return -EINVAL;
190
191 if (!futex_validate_input(iof->futex_flags, iof->futex_val) ||
192 !futex_validate_input(iof->futex_flags, iof->futex_mask))
193 return -EINVAL;
194
195 return 0;
196}
197
198static void io_futex_wakev_fn(struct wake_q_head *wake_q, struct futex_q *q)
199{
200 struct io_kiocb *req = q->wake_data;
201 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
202
203 if (!io_futexv_claim(iof))
204 return;
205 if (unlikely(!__futex_wake_mark(q)))
206 return;
207
208 io_req_set_res(req, 0, 0);
209 req->io_task_work.func = io_futexv_complete;
210 io_req_task_work_add(req);
211}
212
213int io_futexv_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
214{
215 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
216 struct futex_vector *futexv;
217 int ret;
218
219 /* No flags or mask supported for waitv */
220 if (unlikely(sqe->fd || sqe->buf_index || sqe->file_index ||
221 sqe->addr2 || sqe->futex_flags || sqe->addr3))
222 return -EINVAL;
223
224 iof->uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
225 iof->futex_nr = READ_ONCE(sqe->len);
226 if (!iof->futex_nr || iof->futex_nr > FUTEX_WAITV_MAX)
227 return -EINVAL;
228
229 futexv = kcalloc(iof->futex_nr, sizeof(*futexv), GFP_KERNEL);
230 if (!futexv)
231 return -ENOMEM;
232
233 ret = futex_parse_waitv(futexv, iof->uwaitv, iof->futex_nr,
234 io_futex_wakev_fn, req);
235 if (ret) {
236 kfree(futexv);
237 return ret;
238 }
239
240 iof->futexv_owned = 0;
241 iof->futexv_unqueued = 0;
242 req->flags |= REQ_F_ASYNC_DATA;
243 req->async_data = futexv;
244 return 0;
245}
246
247static void io_futex_wake_fn(struct wake_q_head *wake_q, struct futex_q *q)
248{
249 struct io_futex_data *ifd = container_of(q, struct io_futex_data, q);
250 struct io_kiocb *req = ifd->req;
251
252 if (unlikely(!__futex_wake_mark(q)))
253 return;
254
255 io_req_set_res(req, 0, 0);
256 req->io_task_work.func = io_futex_complete;
257 io_req_task_work_add(req);
258}
259
260static struct io_futex_data *io_alloc_ifd(struct io_ring_ctx *ctx)
261{
262 struct io_cache_entry *entry;
263
264 entry = io_alloc_cache_get(&ctx->futex_cache);
265 if (entry)
266 return container_of(entry, struct io_futex_data, cache);
267
268 return kmalloc(sizeof(struct io_futex_data), GFP_NOWAIT);
269}
270
271int io_futexv_wait(struct io_kiocb *req, unsigned int issue_flags)
272{
273 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
274 struct futex_vector *futexv = req->async_data;
275 struct io_ring_ctx *ctx = req->ctx;
276 int ret, woken = -1;
277
278 io_ring_submit_lock(ctx, issue_flags);
279
280 ret = futex_wait_multiple_setup(futexv, iof->futex_nr, &woken);
281
282 /*
283 * Error case, ret is < 0. Mark the request as failed.
284 */
285 if (unlikely(ret < 0)) {
286 io_ring_submit_unlock(ctx, issue_flags);
287 req_set_fail(req);
288 io_req_set_res(req, ret, 0);
289 kfree(futexv);
290 req->async_data = NULL;
291 req->flags &= ~REQ_F_ASYNC_DATA;
292 return IOU_OK;
293 }
294
295 /*
296 * 0 return means that we successfully setup the waiters, and that
297 * nobody triggered a wakeup while we were doing so. If the wakeup
298 * happened post setup, the task_work will be run post this issue and
299 * under the submission lock. 1 means We got woken while setting up,
300 * let that side do the completion. Note that
301 * futex_wait_multiple_setup() will have unqueued all the futexes in
302 * this case. Mark us as having done that already, since this is
303 * different from normal wakeup.
304 */
305 if (!ret) {
306 /*
307 * If futex_wait_multiple_setup() returns 0 for a
308 * successful setup, then the task state will not be
309 * runnable. This is fine for the sync syscall, as
310 * it'll be blocking unless we already got one of the
311 * futexes woken, but it obviously won't work for an
312 * async invocation. Mark us runnable again.
313 */
314 __set_current_state(TASK_RUNNING);
315 hlist_add_head(&req->hash_node, &ctx->futex_list);
316 } else {
317 iof->futexv_unqueued = 1;
318 if (woken != -1)
319 io_req_set_res(req, woken, 0);
320 }
321
322 io_ring_submit_unlock(ctx, issue_flags);
323 return IOU_ISSUE_SKIP_COMPLETE;
324}
325
326int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags)
327{
328 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
329 struct io_ring_ctx *ctx = req->ctx;
330 struct io_futex_data *ifd = NULL;
331 struct futex_hash_bucket *hb;
332 int ret;
333
334 if (!iof->futex_mask) {
335 ret = -EINVAL;
336 goto done;
337 }
338
339 io_ring_submit_lock(ctx, issue_flags);
340 ifd = io_alloc_ifd(ctx);
341 if (!ifd) {
342 ret = -ENOMEM;
343 goto done_unlock;
344 }
345
346 req->async_data = ifd;
347 ifd->q = futex_q_init;
348 ifd->q.bitset = iof->futex_mask;
349 ifd->q.wake = io_futex_wake_fn;
350 ifd->req = req;
351
352 ret = futex_wait_setup(iof->uaddr, iof->futex_val, iof->futex_flags,
353 &ifd->q, &hb);
354 if (!ret) {
355 hlist_add_head(&req->hash_node, &ctx->futex_list);
356 io_ring_submit_unlock(ctx, issue_flags);
357
358 futex_queue(&ifd->q, hb);
359 return IOU_ISSUE_SKIP_COMPLETE;
360 }
361
362done_unlock:
363 io_ring_submit_unlock(ctx, issue_flags);
364done:
365 if (ret < 0)
366 req_set_fail(req);
367 io_req_set_res(req, ret, 0);
368 kfree(ifd);
369 return IOU_OK;
370}
371
372int io_futex_wake(struct io_kiocb *req, unsigned int issue_flags)
373{
374 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
375 int ret;
376
377 /*
378 * Strict flags - ensure that waking 0 futexes yields a 0 result.
379 * See commit 43adf8449510 ("futex: FLAGS_STRICT") for details.
380 */
381 ret = futex_wake(iof->uaddr, FLAGS_STRICT | iof->futex_flags,
382 iof->futex_val, iof->futex_mask);
383 if (ret < 0)
384 req_set_fail(req);
385 io_req_set_res(req, ret, 0);
386 return IOU_OK;
387}
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/io_uring.h>
7
8#include <uapi/linux/io_uring.h>
9
10#include "../kernel/futex/futex.h"
11#include "io_uring.h"
12#include "rsrc.h"
13#include "futex.h"
14
15struct io_futex {
16 struct file *file;
17 union {
18 u32 __user *uaddr;
19 struct futex_waitv __user *uwaitv;
20 };
21 unsigned long futex_val;
22 unsigned long futex_mask;
23 unsigned long futexv_owned;
24 u32 futex_flags;
25 unsigned int futex_nr;
26 bool futexv_unqueued;
27};
28
29struct io_futex_data {
30 union {
31 struct futex_q q;
32 struct io_cache_entry cache;
33 };
34 struct io_kiocb *req;
35};
36
37void io_futex_cache_init(struct io_ring_ctx *ctx)
38{
39 io_alloc_cache_init(&ctx->futex_cache, IO_NODE_ALLOC_CACHE_MAX,
40 sizeof(struct io_futex_data));
41}
42
43static void io_futex_cache_entry_free(struct io_cache_entry *entry)
44{
45 kfree(container_of(entry, struct io_futex_data, cache));
46}
47
48void io_futex_cache_free(struct io_ring_ctx *ctx)
49{
50 io_alloc_cache_free(&ctx->futex_cache, io_futex_cache_entry_free);
51}
52
53static void __io_futex_complete(struct io_kiocb *req, struct io_tw_state *ts)
54{
55 req->async_data = NULL;
56 hlist_del_init(&req->hash_node);
57 io_req_task_complete(req, ts);
58}
59
60static void io_futex_complete(struct io_kiocb *req, struct io_tw_state *ts)
61{
62 struct io_futex_data *ifd = req->async_data;
63 struct io_ring_ctx *ctx = req->ctx;
64
65 io_tw_lock(ctx, ts);
66 if (!io_alloc_cache_put(&ctx->futex_cache, &ifd->cache))
67 kfree(ifd);
68 __io_futex_complete(req, ts);
69}
70
71static void io_futexv_complete(struct io_kiocb *req, struct io_tw_state *ts)
72{
73 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
74 struct futex_vector *futexv = req->async_data;
75
76 io_tw_lock(req->ctx, ts);
77
78 if (!iof->futexv_unqueued) {
79 int res;
80
81 res = futex_unqueue_multiple(futexv, iof->futex_nr);
82 if (res != -1)
83 io_req_set_res(req, res, 0);
84 }
85
86 kfree(req->async_data);
87 req->flags &= ~REQ_F_ASYNC_DATA;
88 __io_futex_complete(req, ts);
89}
90
91static bool io_futexv_claim(struct io_futex *iof)
92{
93 if (test_bit(0, &iof->futexv_owned) ||
94 test_and_set_bit_lock(0, &iof->futexv_owned))
95 return false;
96 return true;
97}
98
99static bool __io_futex_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req)
100{
101 /* futex wake already done or in progress */
102 if (req->opcode == IORING_OP_FUTEX_WAIT) {
103 struct io_futex_data *ifd = req->async_data;
104
105 if (!futex_unqueue(&ifd->q))
106 return false;
107 req->io_task_work.func = io_futex_complete;
108 } else {
109 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
110
111 if (!io_futexv_claim(iof))
112 return false;
113 req->io_task_work.func = io_futexv_complete;
114 }
115
116 hlist_del_init(&req->hash_node);
117 io_req_set_res(req, -ECANCELED, 0);
118 io_req_task_work_add(req);
119 return true;
120}
121
122int io_futex_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
123 unsigned int issue_flags)
124{
125 struct hlist_node *tmp;
126 struct io_kiocb *req;
127 int nr = 0;
128
129 if (cd->flags & (IORING_ASYNC_CANCEL_FD|IORING_ASYNC_CANCEL_FD_FIXED))
130 return -ENOENT;
131
132 io_ring_submit_lock(ctx, issue_flags);
133 hlist_for_each_entry_safe(req, tmp, &ctx->futex_list, hash_node) {
134 if (req->cqe.user_data != cd->data &&
135 !(cd->flags & IORING_ASYNC_CANCEL_ANY))
136 continue;
137 if (__io_futex_cancel(ctx, req))
138 nr++;
139 if (!(cd->flags & IORING_ASYNC_CANCEL_ALL))
140 break;
141 }
142 io_ring_submit_unlock(ctx, issue_flags);
143
144 if (nr)
145 return nr;
146
147 return -ENOENT;
148}
149
150bool io_futex_remove_all(struct io_ring_ctx *ctx, struct task_struct *task,
151 bool cancel_all)
152{
153 struct hlist_node *tmp;
154 struct io_kiocb *req;
155 bool found = false;
156
157 lockdep_assert_held(&ctx->uring_lock);
158
159 hlist_for_each_entry_safe(req, tmp, &ctx->futex_list, hash_node) {
160 if (!io_match_task_safe(req, task, cancel_all))
161 continue;
162 __io_futex_cancel(ctx, req);
163 found = true;
164 }
165
166 return found;
167}
168
169int io_futex_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
170{
171 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
172 u32 flags;
173
174 if (unlikely(sqe->len || sqe->futex_flags || sqe->buf_index ||
175 sqe->file_index))
176 return -EINVAL;
177
178 iof->uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
179 iof->futex_val = READ_ONCE(sqe->addr2);
180 iof->futex_mask = READ_ONCE(sqe->addr3);
181 flags = READ_ONCE(sqe->fd);
182
183 if (flags & ~FUTEX2_VALID_MASK)
184 return -EINVAL;
185
186 iof->futex_flags = futex2_to_flags(flags);
187 if (!futex_flags_valid(iof->futex_flags))
188 return -EINVAL;
189
190 if (!futex_validate_input(iof->futex_flags, iof->futex_val) ||
191 !futex_validate_input(iof->futex_flags, iof->futex_mask))
192 return -EINVAL;
193
194 return 0;
195}
196
197static void io_futex_wakev_fn(struct wake_q_head *wake_q, struct futex_q *q)
198{
199 struct io_kiocb *req = q->wake_data;
200 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
201
202 if (!io_futexv_claim(iof))
203 return;
204 if (unlikely(!__futex_wake_mark(q)))
205 return;
206
207 io_req_set_res(req, 0, 0);
208 req->io_task_work.func = io_futexv_complete;
209 io_req_task_work_add(req);
210}
211
212int io_futexv_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
213{
214 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
215 struct futex_vector *futexv;
216 int ret;
217
218 /* No flags or mask supported for waitv */
219 if (unlikely(sqe->fd || sqe->buf_index || sqe->file_index ||
220 sqe->addr2 || sqe->futex_flags || sqe->addr3))
221 return -EINVAL;
222
223 iof->uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
224 iof->futex_nr = READ_ONCE(sqe->len);
225 if (!iof->futex_nr || iof->futex_nr > FUTEX_WAITV_MAX)
226 return -EINVAL;
227
228 futexv = kcalloc(iof->futex_nr, sizeof(*futexv), GFP_KERNEL);
229 if (!futexv)
230 return -ENOMEM;
231
232 ret = futex_parse_waitv(futexv, iof->uwaitv, iof->futex_nr,
233 io_futex_wakev_fn, req);
234 if (ret) {
235 kfree(futexv);
236 return ret;
237 }
238
239 iof->futexv_owned = 0;
240 iof->futexv_unqueued = 0;
241 req->flags |= REQ_F_ASYNC_DATA;
242 req->async_data = futexv;
243 return 0;
244}
245
246static void io_futex_wake_fn(struct wake_q_head *wake_q, struct futex_q *q)
247{
248 struct io_futex_data *ifd = container_of(q, struct io_futex_data, q);
249 struct io_kiocb *req = ifd->req;
250
251 if (unlikely(!__futex_wake_mark(q)))
252 return;
253
254 io_req_set_res(req, 0, 0);
255 req->io_task_work.func = io_futex_complete;
256 io_req_task_work_add(req);
257}
258
259static struct io_futex_data *io_alloc_ifd(struct io_ring_ctx *ctx)
260{
261 struct io_cache_entry *entry;
262
263 entry = io_alloc_cache_get(&ctx->futex_cache);
264 if (entry)
265 return container_of(entry, struct io_futex_data, cache);
266
267 return kmalloc(sizeof(struct io_futex_data), GFP_NOWAIT);
268}
269
270int io_futexv_wait(struct io_kiocb *req, unsigned int issue_flags)
271{
272 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
273 struct futex_vector *futexv = req->async_data;
274 struct io_ring_ctx *ctx = req->ctx;
275 int ret, woken = -1;
276
277 io_ring_submit_lock(ctx, issue_flags);
278
279 ret = futex_wait_multiple_setup(futexv, iof->futex_nr, &woken);
280
281 /*
282 * Error case, ret is < 0. Mark the request as failed.
283 */
284 if (unlikely(ret < 0)) {
285 io_ring_submit_unlock(ctx, issue_flags);
286 req_set_fail(req);
287 io_req_set_res(req, ret, 0);
288 kfree(futexv);
289 req->async_data = NULL;
290 req->flags &= ~REQ_F_ASYNC_DATA;
291 return IOU_OK;
292 }
293
294 /*
295 * 0 return means that we successfully setup the waiters, and that
296 * nobody triggered a wakeup while we were doing so. If the wakeup
297 * happened post setup, the task_work will be run post this issue and
298 * under the submission lock. 1 means We got woken while setting up,
299 * let that side do the completion. Note that
300 * futex_wait_multiple_setup() will have unqueued all the futexes in
301 * this case. Mark us as having done that already, since this is
302 * different from normal wakeup.
303 */
304 if (!ret) {
305 /*
306 * If futex_wait_multiple_setup() returns 0 for a
307 * successful setup, then the task state will not be
308 * runnable. This is fine for the sync syscall, as
309 * it'll be blocking unless we already got one of the
310 * futexes woken, but it obviously won't work for an
311 * async invocation. Mark us runnable again.
312 */
313 __set_current_state(TASK_RUNNING);
314 hlist_add_head(&req->hash_node, &ctx->futex_list);
315 } else {
316 iof->futexv_unqueued = 1;
317 if (woken != -1)
318 io_req_set_res(req, woken, 0);
319 }
320
321 io_ring_submit_unlock(ctx, issue_flags);
322 return IOU_ISSUE_SKIP_COMPLETE;
323}
324
325int io_futex_wait(struct io_kiocb *req, unsigned int issue_flags)
326{
327 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
328 struct io_ring_ctx *ctx = req->ctx;
329 struct io_futex_data *ifd = NULL;
330 struct futex_hash_bucket *hb;
331 int ret;
332
333 if (!iof->futex_mask) {
334 ret = -EINVAL;
335 goto done;
336 }
337
338 io_ring_submit_lock(ctx, issue_flags);
339 ifd = io_alloc_ifd(ctx);
340 if (!ifd) {
341 ret = -ENOMEM;
342 goto done_unlock;
343 }
344
345 req->async_data = ifd;
346 ifd->q = futex_q_init;
347 ifd->q.bitset = iof->futex_mask;
348 ifd->q.wake = io_futex_wake_fn;
349 ifd->req = req;
350
351 ret = futex_wait_setup(iof->uaddr, iof->futex_val, iof->futex_flags,
352 &ifd->q, &hb);
353 if (!ret) {
354 hlist_add_head(&req->hash_node, &ctx->futex_list);
355 io_ring_submit_unlock(ctx, issue_flags);
356
357 futex_queue(&ifd->q, hb);
358 return IOU_ISSUE_SKIP_COMPLETE;
359 }
360
361done_unlock:
362 io_ring_submit_unlock(ctx, issue_flags);
363done:
364 if (ret < 0)
365 req_set_fail(req);
366 io_req_set_res(req, ret, 0);
367 kfree(ifd);
368 return IOU_OK;
369}
370
371int io_futex_wake(struct io_kiocb *req, unsigned int issue_flags)
372{
373 struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
374 int ret;
375
376 /*
377 * Strict flags - ensure that waking 0 futexes yields a 0 result.
378 * See commit 43adf8449510 ("futex: FLAGS_STRICT") for details.
379 */
380 ret = futex_wake(iof->uaddr, FLAGS_STRICT | iof->futex_flags,
381 iof->futex_val, iof->futex_mask);
382 if (ret < 0)
383 req_set_fail(req);
384 io_req_set_res(req, ret, 0);
385 return IOU_OK;
386}