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73572984 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/nospec.h> | |
9 | #include <linux/hugetlb.h> | |
10 | #include <linux/compat.h> | |
11 | #include <linux/io_uring.h> | |
12 | ||
13 | #include <uapi/linux/io_uring.h> | |
14 | ||
73572984 JA |
15 | #include "io_uring.h" |
16 | #include "openclose.h" | |
17 | #include "rsrc.h" | |
18 | ||
19 | struct io_rsrc_update { | |
20 | struct file *file; | |
21 | u64 arg; | |
22 | u32 nr_args; | |
23 | u32 offset; | |
24 | }; | |
25 | ||
26 | static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov, | |
27 | struct io_mapped_ubuf **pimu, | |
28 | struct page **last_hpage); | |
29 | ||
30 | #define IO_RSRC_REF_BATCH 100 | |
31 | ||
32 | /* only define max */ | |
33 | #define IORING_MAX_FIXED_FILES (1U << 20) | |
34 | #define IORING_MAX_REG_BUFFERS (1U << 14) | |
35 | ||
36 | void io_rsrc_refs_drop(struct io_ring_ctx *ctx) | |
37 | __must_hold(&ctx->uring_lock) | |
38 | { | |
39 | if (ctx->rsrc_cached_refs) { | |
40 | io_rsrc_put_node(ctx->rsrc_node, ctx->rsrc_cached_refs); | |
41 | ctx->rsrc_cached_refs = 0; | |
42 | } | |
43 | } | |
44 | ||
6a9ce66f | 45 | int __io_account_mem(struct user_struct *user, unsigned long nr_pages) |
73572984 JA |
46 | { |
47 | unsigned long page_limit, cur_pages, new_pages; | |
48 | ||
6a9ce66f PB |
49 | if (!nr_pages) |
50 | return 0; | |
51 | ||
73572984 JA |
52 | /* Don't allow more pages than we can safely lock */ |
53 | page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; | |
54 | ||
4ccc6db0 | 55 | cur_pages = atomic_long_read(&user->locked_vm); |
73572984 | 56 | do { |
73572984 JA |
57 | new_pages = cur_pages + nr_pages; |
58 | if (new_pages > page_limit) | |
59 | return -ENOMEM; | |
4ccc6db0 UB |
60 | } while (!atomic_long_try_cmpxchg(&user->locked_vm, |
61 | &cur_pages, new_pages)); | |
73572984 JA |
62 | return 0; |
63 | } | |
64 | ||
65 | static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages) | |
66 | { | |
67 | if (ctx->user) | |
68 | __io_unaccount_mem(ctx->user, nr_pages); | |
69 | ||
70 | if (ctx->mm_account) | |
71 | atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm); | |
72 | } | |
73 | ||
74 | static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages) | |
75 | { | |
76 | int ret; | |
77 | ||
78 | if (ctx->user) { | |
79 | ret = __io_account_mem(ctx->user, nr_pages); | |
80 | if (ret) | |
81 | return ret; | |
82 | } | |
83 | ||
84 | if (ctx->mm_account) | |
85 | atomic64_add(nr_pages, &ctx->mm_account->pinned_vm); | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
90 | static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst, | |
91 | void __user *arg, unsigned index) | |
92 | { | |
93 | struct iovec __user *src; | |
94 | ||
95 | #ifdef CONFIG_COMPAT | |
96 | if (ctx->compat) { | |
97 | struct compat_iovec __user *ciovs; | |
98 | struct compat_iovec ciov; | |
99 | ||
100 | ciovs = (struct compat_iovec __user *) arg; | |
101 | if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov))) | |
102 | return -EFAULT; | |
103 | ||
104 | dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base); | |
105 | dst->iov_len = ciov.iov_len; | |
106 | return 0; | |
107 | } | |
108 | #endif | |
109 | src = (struct iovec __user *) arg; | |
110 | if (copy_from_user(dst, &src[index], sizeof(*dst))) | |
111 | return -EFAULT; | |
112 | return 0; | |
113 | } | |
114 | ||
115 | static int io_buffer_validate(struct iovec *iov) | |
116 | { | |
117 | unsigned long tmp, acct_len = iov->iov_len + (PAGE_SIZE - 1); | |
118 | ||
119 | /* | |
120 | * Don't impose further limits on the size and buffer | |
121 | * constraints here, we'll -EINVAL later when IO is | |
122 | * submitted if they are wrong. | |
123 | */ | |
124 | if (!iov->iov_base) | |
125 | return iov->iov_len ? -EFAULT : 0; | |
126 | if (!iov->iov_len) | |
127 | return -EFAULT; | |
128 | ||
129 | /* arbitrary limit, but we need something */ | |
130 | if (iov->iov_len > SZ_1G) | |
131 | return -EFAULT; | |
132 | ||
133 | if (check_add_overflow((unsigned long)iov->iov_base, acct_len, &tmp)) | |
134 | return -EOVERFLOW; | |
135 | ||
136 | return 0; | |
137 | } | |
138 | ||
139 | static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slot) | |
140 | { | |
141 | struct io_mapped_ubuf *imu = *slot; | |
142 | unsigned int i; | |
143 | ||
144 | if (imu != ctx->dummy_ubuf) { | |
145 | for (i = 0; i < imu->nr_bvecs; i++) | |
146 | unpin_user_page(imu->bvec[i].bv_page); | |
147 | if (imu->acct_pages) | |
148 | io_unaccount_mem(ctx, imu->acct_pages); | |
149 | kvfree(imu); | |
150 | } | |
151 | *slot = NULL; | |
152 | } | |
153 | ||
154 | void io_rsrc_refs_refill(struct io_ring_ctx *ctx) | |
155 | __must_hold(&ctx->uring_lock) | |
156 | { | |
157 | ctx->rsrc_cached_refs += IO_RSRC_REF_BATCH; | |
158 | percpu_ref_get_many(&ctx->rsrc_node->refs, IO_RSRC_REF_BATCH); | |
159 | } | |
160 | ||
161 | static void __io_rsrc_put_work(struct io_rsrc_node *ref_node) | |
162 | { | |
163 | struct io_rsrc_data *rsrc_data = ref_node->rsrc_data; | |
164 | struct io_ring_ctx *ctx = rsrc_data->ctx; | |
165 | struct io_rsrc_put *prsrc, *tmp; | |
166 | ||
167 | list_for_each_entry_safe(prsrc, tmp, &ref_node->rsrc_list, list) { | |
168 | list_del(&prsrc->list); | |
169 | ||
170 | if (prsrc->tag) { | |
d245bca6 | 171 | if (ctx->flags & IORING_SETUP_IOPOLL) { |
73572984 | 172 | mutex_lock(&ctx->uring_lock); |
52120f0f | 173 | io_post_aux_cqe(ctx, prsrc->tag, 0, 0, true); |
73572984 | 174 | mutex_unlock(&ctx->uring_lock); |
d245bca6 | 175 | } else { |
52120f0f | 176 | io_post_aux_cqe(ctx, prsrc->tag, 0, 0, true); |
d245bca6 | 177 | } |
73572984 JA |
178 | } |
179 | ||
180 | rsrc_data->do_put(ctx, prsrc); | |
181 | kfree(prsrc); | |
182 | } | |
183 | ||
184 | io_rsrc_node_destroy(ref_node); | |
185 | if (atomic_dec_and_test(&rsrc_data->refs)) | |
186 | complete(&rsrc_data->done); | |
187 | } | |
188 | ||
189 | void io_rsrc_put_work(struct work_struct *work) | |
190 | { | |
191 | struct io_ring_ctx *ctx; | |
192 | struct llist_node *node; | |
193 | ||
194 | ctx = container_of(work, struct io_ring_ctx, rsrc_put_work.work); | |
195 | node = llist_del_all(&ctx->rsrc_put_llist); | |
196 | ||
197 | while (node) { | |
198 | struct io_rsrc_node *ref_node; | |
199 | struct llist_node *next = node->next; | |
200 | ||
201 | ref_node = llist_entry(node, struct io_rsrc_node, llist); | |
202 | __io_rsrc_put_work(ref_node); | |
203 | node = next; | |
204 | } | |
205 | } | |
206 | ||
207 | void io_wait_rsrc_data(struct io_rsrc_data *data) | |
208 | { | |
209 | if (data && !atomic_dec_and_test(&data->refs)) | |
210 | wait_for_completion(&data->done); | |
211 | } | |
212 | ||
213 | void io_rsrc_node_destroy(struct io_rsrc_node *ref_node) | |
214 | { | |
215 | percpu_ref_exit(&ref_node->refs); | |
216 | kfree(ref_node); | |
217 | } | |
218 | ||
219 | static __cold void io_rsrc_node_ref_zero(struct percpu_ref *ref) | |
220 | { | |
221 | struct io_rsrc_node *node = container_of(ref, struct io_rsrc_node, refs); | |
222 | struct io_ring_ctx *ctx = node->rsrc_data->ctx; | |
223 | unsigned long flags; | |
224 | bool first_add = false; | |
225 | unsigned long delay = HZ; | |
226 | ||
227 | spin_lock_irqsave(&ctx->rsrc_ref_lock, flags); | |
228 | node->done = true; | |
229 | ||
230 | /* if we are mid-quiesce then do not delay */ | |
231 | if (node->rsrc_data->quiesce) | |
232 | delay = 0; | |
233 | ||
234 | while (!list_empty(&ctx->rsrc_ref_list)) { | |
235 | node = list_first_entry(&ctx->rsrc_ref_list, | |
236 | struct io_rsrc_node, node); | |
237 | /* recycle ref nodes in order */ | |
238 | if (!node->done) | |
239 | break; | |
240 | list_del(&node->node); | |
241 | first_add |= llist_add(&node->llist, &ctx->rsrc_put_llist); | |
242 | } | |
243 | spin_unlock_irqrestore(&ctx->rsrc_ref_lock, flags); | |
244 | ||
245 | if (first_add) | |
246 | mod_delayed_work(system_wq, &ctx->rsrc_put_work, delay); | |
247 | } | |
248 | ||
249 | static struct io_rsrc_node *io_rsrc_node_alloc(void) | |
250 | { | |
251 | struct io_rsrc_node *ref_node; | |
252 | ||
253 | ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL); | |
254 | if (!ref_node) | |
255 | return NULL; | |
256 | ||
257 | if (percpu_ref_init(&ref_node->refs, io_rsrc_node_ref_zero, | |
258 | 0, GFP_KERNEL)) { | |
259 | kfree(ref_node); | |
260 | return NULL; | |
261 | } | |
262 | INIT_LIST_HEAD(&ref_node->node); | |
263 | INIT_LIST_HEAD(&ref_node->rsrc_list); | |
264 | ref_node->done = false; | |
265 | return ref_node; | |
266 | } | |
267 | ||
268 | void io_rsrc_node_switch(struct io_ring_ctx *ctx, | |
269 | struct io_rsrc_data *data_to_kill) | |
270 | __must_hold(&ctx->uring_lock) | |
271 | { | |
272 | WARN_ON_ONCE(!ctx->rsrc_backup_node); | |
273 | WARN_ON_ONCE(data_to_kill && !ctx->rsrc_node); | |
274 | ||
275 | io_rsrc_refs_drop(ctx); | |
276 | ||
277 | if (data_to_kill) { | |
278 | struct io_rsrc_node *rsrc_node = ctx->rsrc_node; | |
279 | ||
280 | rsrc_node->rsrc_data = data_to_kill; | |
281 | spin_lock_irq(&ctx->rsrc_ref_lock); | |
282 | list_add_tail(&rsrc_node->node, &ctx->rsrc_ref_list); | |
283 | spin_unlock_irq(&ctx->rsrc_ref_lock); | |
284 | ||
285 | atomic_inc(&data_to_kill->refs); | |
286 | percpu_ref_kill(&rsrc_node->refs); | |
287 | ctx->rsrc_node = NULL; | |
288 | } | |
289 | ||
290 | if (!ctx->rsrc_node) { | |
291 | ctx->rsrc_node = ctx->rsrc_backup_node; | |
292 | ctx->rsrc_backup_node = NULL; | |
293 | } | |
294 | } | |
295 | ||
296 | int io_rsrc_node_switch_start(struct io_ring_ctx *ctx) | |
297 | { | |
298 | if (ctx->rsrc_backup_node) | |
299 | return 0; | |
300 | ctx->rsrc_backup_node = io_rsrc_node_alloc(); | |
301 | return ctx->rsrc_backup_node ? 0 : -ENOMEM; | |
302 | } | |
303 | ||
304 | __cold static int io_rsrc_ref_quiesce(struct io_rsrc_data *data, | |
305 | struct io_ring_ctx *ctx) | |
306 | { | |
307 | int ret; | |
308 | ||
309 | /* As we may drop ->uring_lock, other task may have started quiesce */ | |
310 | if (data->quiesce) | |
311 | return -ENXIO; | |
312 | ||
313 | data->quiesce = true; | |
314 | do { | |
315 | ret = io_rsrc_node_switch_start(ctx); | |
316 | if (ret) | |
317 | break; | |
318 | io_rsrc_node_switch(ctx, data); | |
319 | ||
320 | /* kill initial ref, already quiesced if zero */ | |
321 | if (atomic_dec_and_test(&data->refs)) | |
322 | break; | |
323 | mutex_unlock(&ctx->uring_lock); | |
324 | flush_delayed_work(&ctx->rsrc_put_work); | |
325 | ret = wait_for_completion_interruptible(&data->done); | |
326 | if (!ret) { | |
327 | mutex_lock(&ctx->uring_lock); | |
328 | if (atomic_read(&data->refs) > 0) { | |
329 | /* | |
330 | * it has been revived by another thread while | |
331 | * we were unlocked | |
332 | */ | |
333 | mutex_unlock(&ctx->uring_lock); | |
334 | } else { | |
335 | break; | |
336 | } | |
337 | } | |
338 | ||
339 | atomic_inc(&data->refs); | |
340 | /* wait for all works potentially completing data->done */ | |
341 | flush_delayed_work(&ctx->rsrc_put_work); | |
342 | reinit_completion(&data->done); | |
343 | ||
c0e0d6ba | 344 | ret = io_run_task_work_sig(ctx); |
73572984 JA |
345 | mutex_lock(&ctx->uring_lock); |
346 | } while (ret >= 0); | |
347 | data->quiesce = false; | |
348 | ||
349 | return ret; | |
350 | } | |
351 | ||
352 | static void io_free_page_table(void **table, size_t size) | |
353 | { | |
354 | unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE); | |
355 | ||
356 | for (i = 0; i < nr_tables; i++) | |
357 | kfree(table[i]); | |
358 | kfree(table); | |
359 | } | |
360 | ||
361 | static void io_rsrc_data_free(struct io_rsrc_data *data) | |
362 | { | |
363 | size_t size = data->nr * sizeof(data->tags[0][0]); | |
364 | ||
365 | if (data->tags) | |
366 | io_free_page_table((void **)data->tags, size); | |
367 | kfree(data); | |
368 | } | |
369 | ||
370 | static __cold void **io_alloc_page_table(size_t size) | |
371 | { | |
372 | unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE); | |
373 | size_t init_size = size; | |
374 | void **table; | |
375 | ||
376 | table = kcalloc(nr_tables, sizeof(*table), GFP_KERNEL_ACCOUNT); | |
377 | if (!table) | |
378 | return NULL; | |
379 | ||
380 | for (i = 0; i < nr_tables; i++) { | |
381 | unsigned int this_size = min_t(size_t, size, PAGE_SIZE); | |
382 | ||
383 | table[i] = kzalloc(this_size, GFP_KERNEL_ACCOUNT); | |
384 | if (!table[i]) { | |
385 | io_free_page_table(table, init_size); | |
386 | return NULL; | |
387 | } | |
388 | size -= this_size; | |
389 | } | |
390 | return table; | |
391 | } | |
392 | ||
393 | __cold static int io_rsrc_data_alloc(struct io_ring_ctx *ctx, | |
394 | rsrc_put_fn *do_put, u64 __user *utags, | |
395 | unsigned nr, struct io_rsrc_data **pdata) | |
396 | { | |
397 | struct io_rsrc_data *data; | |
398 | int ret = -ENOMEM; | |
399 | unsigned i; | |
400 | ||
401 | data = kzalloc(sizeof(*data), GFP_KERNEL); | |
402 | if (!data) | |
403 | return -ENOMEM; | |
404 | data->tags = (u64 **)io_alloc_page_table(nr * sizeof(data->tags[0][0])); | |
405 | if (!data->tags) { | |
406 | kfree(data); | |
407 | return -ENOMEM; | |
408 | } | |
409 | ||
410 | data->nr = nr; | |
411 | data->ctx = ctx; | |
412 | data->do_put = do_put; | |
413 | if (utags) { | |
414 | ret = -EFAULT; | |
415 | for (i = 0; i < nr; i++) { | |
416 | u64 *tag_slot = io_get_tag_slot(data, i); | |
417 | ||
418 | if (copy_from_user(tag_slot, &utags[i], | |
419 | sizeof(*tag_slot))) | |
420 | goto fail; | |
421 | } | |
422 | } | |
423 | ||
424 | atomic_set(&data->refs, 1); | |
425 | init_completion(&data->done); | |
426 | *pdata = data; | |
427 | return 0; | |
428 | fail: | |
429 | io_rsrc_data_free(data); | |
430 | return ret; | |
431 | } | |
432 | ||
433 | static int __io_sqe_files_update(struct io_ring_ctx *ctx, | |
434 | struct io_uring_rsrc_update2 *up, | |
435 | unsigned nr_args) | |
436 | { | |
437 | u64 __user *tags = u64_to_user_ptr(up->tags); | |
438 | __s32 __user *fds = u64_to_user_ptr(up->data); | |
439 | struct io_rsrc_data *data = ctx->file_data; | |
440 | struct io_fixed_file *file_slot; | |
441 | struct file *file; | |
442 | int fd, i, err = 0; | |
443 | unsigned int done; | |
444 | bool needs_switch = false; | |
445 | ||
446 | if (!ctx->file_data) | |
447 | return -ENXIO; | |
448 | if (up->offset + nr_args > ctx->nr_user_files) | |
449 | return -EINVAL; | |
450 | ||
451 | for (done = 0; done < nr_args; done++) { | |
452 | u64 tag = 0; | |
453 | ||
454 | if ((tags && copy_from_user(&tag, &tags[done], sizeof(tag))) || | |
455 | copy_from_user(&fd, &fds[done], sizeof(fd))) { | |
456 | err = -EFAULT; | |
457 | break; | |
458 | } | |
459 | if ((fd == IORING_REGISTER_FILES_SKIP || fd == -1) && tag) { | |
460 | err = -EINVAL; | |
461 | break; | |
462 | } | |
463 | if (fd == IORING_REGISTER_FILES_SKIP) | |
464 | continue; | |
465 | ||
466 | i = array_index_nospec(up->offset + done, ctx->nr_user_files); | |
467 | file_slot = io_fixed_file_slot(&ctx->file_table, i); | |
468 | ||
469 | if (file_slot->file_ptr) { | |
470 | file = (struct file *)(file_slot->file_ptr & FFS_MASK); | |
471 | err = io_queue_rsrc_removal(data, i, ctx->rsrc_node, file); | |
472 | if (err) | |
473 | break; | |
474 | file_slot->file_ptr = 0; | |
475 | io_file_bitmap_clear(&ctx->file_table, i); | |
476 | needs_switch = true; | |
477 | } | |
478 | if (fd != -1) { | |
479 | file = fget(fd); | |
480 | if (!file) { | |
481 | err = -EBADF; | |
482 | break; | |
483 | } | |
484 | /* | |
485 | * Don't allow io_uring instances to be registered. If | |
486 | * UNIX isn't enabled, then this causes a reference | |
487 | * cycle and this instance can never get freed. If UNIX | |
488 | * is enabled we'll handle it just fine, but there's | |
489 | * still no point in allowing a ring fd as it doesn't | |
490 | * support regular read/write anyway. | |
491 | */ | |
492 | if (io_is_uring_fops(file)) { | |
493 | fput(file); | |
494 | err = -EBADF; | |
495 | break; | |
496 | } | |
497 | err = io_scm_file_account(ctx, file); | |
498 | if (err) { | |
499 | fput(file); | |
500 | break; | |
501 | } | |
502 | *io_get_tag_slot(data, i) = tag; | |
503 | io_fixed_file_set(file_slot, file); | |
504 | io_file_bitmap_set(&ctx->file_table, i); | |
505 | } | |
506 | } | |
507 | ||
508 | if (needs_switch) | |
509 | io_rsrc_node_switch(ctx, data); | |
510 | return done ? done : err; | |
511 | } | |
512 | ||
513 | static int __io_sqe_buffers_update(struct io_ring_ctx *ctx, | |
514 | struct io_uring_rsrc_update2 *up, | |
515 | unsigned int nr_args) | |
516 | { | |
517 | u64 __user *tags = u64_to_user_ptr(up->tags); | |
518 | struct iovec iov, __user *iovs = u64_to_user_ptr(up->data); | |
519 | struct page *last_hpage = NULL; | |
520 | bool needs_switch = false; | |
521 | __u32 done; | |
522 | int i, err; | |
523 | ||
524 | if (!ctx->buf_data) | |
525 | return -ENXIO; | |
526 | if (up->offset + nr_args > ctx->nr_user_bufs) | |
527 | return -EINVAL; | |
528 | ||
529 | for (done = 0; done < nr_args; done++) { | |
530 | struct io_mapped_ubuf *imu; | |
531 | int offset = up->offset + done; | |
532 | u64 tag = 0; | |
533 | ||
534 | err = io_copy_iov(ctx, &iov, iovs, done); | |
535 | if (err) | |
536 | break; | |
537 | if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) { | |
538 | err = -EFAULT; | |
539 | break; | |
540 | } | |
541 | err = io_buffer_validate(&iov); | |
542 | if (err) | |
543 | break; | |
544 | if (!iov.iov_base && tag) { | |
545 | err = -EINVAL; | |
546 | break; | |
547 | } | |
548 | err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage); | |
549 | if (err) | |
550 | break; | |
551 | ||
552 | i = array_index_nospec(offset, ctx->nr_user_bufs); | |
553 | if (ctx->user_bufs[i] != ctx->dummy_ubuf) { | |
554 | err = io_queue_rsrc_removal(ctx->buf_data, i, | |
555 | ctx->rsrc_node, ctx->user_bufs[i]); | |
556 | if (unlikely(err)) { | |
557 | io_buffer_unmap(ctx, &imu); | |
558 | break; | |
559 | } | |
5ff4fdff | 560 | ctx->user_bufs[i] = ctx->dummy_ubuf; |
73572984 JA |
561 | needs_switch = true; |
562 | } | |
563 | ||
564 | ctx->user_bufs[i] = imu; | |
565 | *io_get_tag_slot(ctx->buf_data, offset) = tag; | |
566 | } | |
567 | ||
568 | if (needs_switch) | |
569 | io_rsrc_node_switch(ctx, ctx->buf_data); | |
570 | return done ? done : err; | |
571 | } | |
572 | ||
573 | static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type, | |
574 | struct io_uring_rsrc_update2 *up, | |
575 | unsigned nr_args) | |
576 | { | |
577 | __u32 tmp; | |
578 | int err; | |
579 | ||
580 | if (check_add_overflow(up->offset, nr_args, &tmp)) | |
581 | return -EOVERFLOW; | |
582 | err = io_rsrc_node_switch_start(ctx); | |
583 | if (err) | |
584 | return err; | |
585 | ||
586 | switch (type) { | |
587 | case IORING_RSRC_FILE: | |
588 | return __io_sqe_files_update(ctx, up, nr_args); | |
589 | case IORING_RSRC_BUFFER: | |
590 | return __io_sqe_buffers_update(ctx, up, nr_args); | |
591 | } | |
592 | return -EINVAL; | |
593 | } | |
594 | ||
595 | int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg, | |
596 | unsigned nr_args) | |
597 | { | |
598 | struct io_uring_rsrc_update2 up; | |
599 | ||
600 | if (!nr_args) | |
601 | return -EINVAL; | |
602 | memset(&up, 0, sizeof(up)); | |
603 | if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update))) | |
604 | return -EFAULT; | |
605 | if (up.resv || up.resv2) | |
606 | return -EINVAL; | |
607 | return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args); | |
608 | } | |
609 | ||
610 | int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg, | |
611 | unsigned size, unsigned type) | |
612 | { | |
613 | struct io_uring_rsrc_update2 up; | |
614 | ||
615 | if (size != sizeof(up)) | |
616 | return -EINVAL; | |
617 | if (copy_from_user(&up, arg, sizeof(up))) | |
618 | return -EFAULT; | |
619 | if (!up.nr || up.resv || up.resv2) | |
620 | return -EINVAL; | |
621 | return __io_register_rsrc_update(ctx, type, &up, up.nr); | |
622 | } | |
623 | ||
624 | __cold int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg, | |
625 | unsigned int size, unsigned int type) | |
626 | { | |
627 | struct io_uring_rsrc_register rr; | |
628 | ||
629 | /* keep it extendible */ | |
630 | if (size != sizeof(rr)) | |
631 | return -EINVAL; | |
632 | ||
633 | memset(&rr, 0, sizeof(rr)); | |
634 | if (copy_from_user(&rr, arg, size)) | |
635 | return -EFAULT; | |
636 | if (!rr.nr || rr.resv2) | |
637 | return -EINVAL; | |
638 | if (rr.flags & ~IORING_RSRC_REGISTER_SPARSE) | |
639 | return -EINVAL; | |
640 | ||
641 | switch (type) { | |
642 | case IORING_RSRC_FILE: | |
643 | if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data) | |
644 | break; | |
645 | return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data), | |
646 | rr.nr, u64_to_user_ptr(rr.tags)); | |
647 | case IORING_RSRC_BUFFER: | |
648 | if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data) | |
649 | break; | |
650 | return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data), | |
651 | rr.nr, u64_to_user_ptr(rr.tags)); | |
652 | } | |
653 | return -EINVAL; | |
654 | } | |
655 | ||
d9808ceb | 656 | int io_files_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
73572984 | 657 | { |
f2ccb5ae | 658 | struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update); |
73572984 JA |
659 | |
660 | if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT))) | |
661 | return -EINVAL; | |
662 | if (sqe->rw_flags || sqe->splice_fd_in) | |
663 | return -EINVAL; | |
664 | ||
665 | up->offset = READ_ONCE(sqe->off); | |
666 | up->nr_args = READ_ONCE(sqe->len); | |
667 | if (!up->nr_args) | |
668 | return -EINVAL; | |
669 | up->arg = READ_ONCE(sqe->addr); | |
670 | return 0; | |
671 | } | |
672 | ||
673 | static int io_files_update_with_index_alloc(struct io_kiocb *req, | |
674 | unsigned int issue_flags) | |
675 | { | |
f2ccb5ae | 676 | struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update); |
73572984 JA |
677 | __s32 __user *fds = u64_to_user_ptr(up->arg); |
678 | unsigned int done; | |
679 | struct file *file; | |
680 | int ret, fd; | |
681 | ||
682 | if (!req->ctx->file_data) | |
683 | return -ENXIO; | |
684 | ||
685 | for (done = 0; done < up->nr_args; done++) { | |
686 | if (copy_from_user(&fd, &fds[done], sizeof(fd))) { | |
687 | ret = -EFAULT; | |
688 | break; | |
689 | } | |
690 | ||
691 | file = fget(fd); | |
692 | if (!file) { | |
693 | ret = -EBADF; | |
694 | break; | |
695 | } | |
696 | ret = io_fixed_fd_install(req, issue_flags, file, | |
697 | IORING_FILE_INDEX_ALLOC); | |
698 | if (ret < 0) | |
699 | break; | |
700 | if (copy_to_user(&fds[done], &ret, sizeof(ret))) { | |
f110ed84 | 701 | __io_close_fixed(req->ctx, issue_flags, ret); |
73572984 JA |
702 | ret = -EFAULT; |
703 | break; | |
704 | } | |
705 | } | |
706 | ||
707 | if (done) | |
708 | return done; | |
709 | return ret; | |
710 | } | |
711 | ||
d9808ceb | 712 | int io_files_update(struct io_kiocb *req, unsigned int issue_flags) |
73572984 | 713 | { |
f2ccb5ae | 714 | struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update); |
73572984 JA |
715 | struct io_ring_ctx *ctx = req->ctx; |
716 | struct io_uring_rsrc_update2 up2; | |
717 | int ret; | |
718 | ||
719 | up2.offset = up->offset; | |
720 | up2.data = up->arg; | |
721 | up2.nr = 0; | |
722 | up2.tags = 0; | |
723 | up2.resv = 0; | |
724 | up2.resv2 = 0; | |
725 | ||
726 | if (up->offset == IORING_FILE_INDEX_ALLOC) { | |
727 | ret = io_files_update_with_index_alloc(req, issue_flags); | |
728 | } else { | |
729 | io_ring_submit_lock(ctx, issue_flags); | |
730 | ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE, | |
731 | &up2, up->nr_args); | |
732 | io_ring_submit_unlock(ctx, issue_flags); | |
733 | } | |
734 | ||
735 | if (ret < 0) | |
736 | req_set_fail(req); | |
737 | io_req_set_res(req, ret, 0); | |
738 | return IOU_OK; | |
739 | } | |
740 | ||
741 | int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx, | |
742 | struct io_rsrc_node *node, void *rsrc) | |
743 | { | |
744 | u64 *tag_slot = io_get_tag_slot(data, idx); | |
745 | struct io_rsrc_put *prsrc; | |
746 | ||
747 | prsrc = kzalloc(sizeof(*prsrc), GFP_KERNEL); | |
748 | if (!prsrc) | |
749 | return -ENOMEM; | |
750 | ||
751 | prsrc->tag = *tag_slot; | |
752 | *tag_slot = 0; | |
753 | prsrc->rsrc = rsrc; | |
754 | list_add(&prsrc->list, &node->rsrc_list); | |
755 | return 0; | |
756 | } | |
757 | ||
758 | void __io_sqe_files_unregister(struct io_ring_ctx *ctx) | |
759 | { | |
73572984 JA |
760 | int i; |
761 | ||
762 | for (i = 0; i < ctx->nr_user_files; i++) { | |
763 | struct file *file = io_file_from_index(&ctx->file_table, i); | |
764 | ||
38eddb2c PB |
765 | /* skip scm accounted files, they'll be freed by ->ring_sock */ |
766 | if (!file || io_file_need_scm(file)) | |
73572984 JA |
767 | continue; |
768 | io_file_bitmap_clear(&ctx->file_table, i); | |
769 | fput(file); | |
770 | } | |
73572984 JA |
771 | |
772 | #if defined(CONFIG_UNIX) | |
773 | if (ctx->ring_sock) { | |
774 | struct sock *sock = ctx->ring_sock->sk; | |
775 | struct sk_buff *skb; | |
776 | ||
777 | while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL) | |
778 | kfree_skb(skb); | |
779 | } | |
780 | #endif | |
781 | io_free_file_tables(&ctx->file_table); | |
782 | io_rsrc_data_free(ctx->file_data); | |
783 | ctx->file_data = NULL; | |
784 | ctx->nr_user_files = 0; | |
785 | } | |
786 | ||
787 | int io_sqe_files_unregister(struct io_ring_ctx *ctx) | |
788 | { | |
789 | unsigned nr = ctx->nr_user_files; | |
790 | int ret; | |
791 | ||
792 | if (!ctx->file_data) | |
793 | return -ENXIO; | |
794 | ||
795 | /* | |
796 | * Quiesce may unlock ->uring_lock, and while it's not held | |
797 | * prevent new requests using the table. | |
798 | */ | |
799 | ctx->nr_user_files = 0; | |
800 | ret = io_rsrc_ref_quiesce(ctx->file_data, ctx); | |
801 | ctx->nr_user_files = nr; | |
802 | if (!ret) | |
803 | __io_sqe_files_unregister(ctx); | |
804 | return ret; | |
805 | } | |
806 | ||
807 | /* | |
808 | * Ensure the UNIX gc is aware of our file set, so we are certain that | |
809 | * the io_uring can be safely unregistered on process exit, even if we have | |
810 | * loops in the file referencing. We account only files that can hold other | |
811 | * files because otherwise they can't form a loop and so are not interesting | |
812 | * for GC. | |
813 | */ | |
814 | int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file) | |
815 | { | |
816 | #if defined(CONFIG_UNIX) | |
817 | struct sock *sk = ctx->ring_sock->sk; | |
818 | struct sk_buff_head *head = &sk->sk_receive_queue; | |
819 | struct scm_fp_list *fpl; | |
820 | struct sk_buff *skb; | |
821 | ||
822 | if (likely(!io_file_need_scm(file))) | |
823 | return 0; | |
824 | ||
825 | /* | |
826 | * See if we can merge this file into an existing skb SCM_RIGHTS | |
827 | * file set. If there's no room, fall back to allocating a new skb | |
828 | * and filling it in. | |
829 | */ | |
830 | spin_lock_irq(&head->lock); | |
831 | skb = skb_peek(head); | |
832 | if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD) | |
833 | __skb_unlink(skb, head); | |
834 | else | |
835 | skb = NULL; | |
836 | spin_unlock_irq(&head->lock); | |
837 | ||
838 | if (!skb) { | |
839 | fpl = kzalloc(sizeof(*fpl), GFP_KERNEL); | |
840 | if (!fpl) | |
841 | return -ENOMEM; | |
842 | ||
843 | skb = alloc_skb(0, GFP_KERNEL); | |
844 | if (!skb) { | |
845 | kfree(fpl); | |
846 | return -ENOMEM; | |
847 | } | |
848 | ||
849 | fpl->user = get_uid(current_user()); | |
850 | fpl->max = SCM_MAX_FD; | |
851 | fpl->count = 0; | |
852 | ||
853 | UNIXCB(skb).fp = fpl; | |
854 | skb->sk = sk; | |
0091bfc8 | 855 | skb->scm_io_uring = 1; |
73572984 JA |
856 | skb->destructor = unix_destruct_scm; |
857 | refcount_add(skb->truesize, &sk->sk_wmem_alloc); | |
858 | } | |
859 | ||
860 | fpl = UNIXCB(skb).fp; | |
861 | fpl->fp[fpl->count++] = get_file(file); | |
862 | unix_inflight(fpl->user, file); | |
863 | skb_queue_head(head, skb); | |
864 | fput(file); | |
865 | #endif | |
866 | return 0; | |
867 | } | |
868 | ||
869 | static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc) | |
870 | { | |
871 | struct file *file = prsrc->file; | |
872 | #if defined(CONFIG_UNIX) | |
873 | struct sock *sock = ctx->ring_sock->sk; | |
874 | struct sk_buff_head list, *head = &sock->sk_receive_queue; | |
875 | struct sk_buff *skb; | |
876 | int i; | |
877 | ||
878 | if (!io_file_need_scm(file)) { | |
879 | fput(file); | |
880 | return; | |
881 | } | |
882 | ||
883 | __skb_queue_head_init(&list); | |
884 | ||
885 | /* | |
886 | * Find the skb that holds this file in its SCM_RIGHTS. When found, | |
887 | * remove this entry and rearrange the file array. | |
888 | */ | |
889 | skb = skb_dequeue(head); | |
890 | while (skb) { | |
891 | struct scm_fp_list *fp; | |
892 | ||
893 | fp = UNIXCB(skb).fp; | |
894 | for (i = 0; i < fp->count; i++) { | |
895 | int left; | |
896 | ||
897 | if (fp->fp[i] != file) | |
898 | continue; | |
899 | ||
900 | unix_notinflight(fp->user, fp->fp[i]); | |
901 | left = fp->count - 1 - i; | |
902 | if (left) { | |
903 | memmove(&fp->fp[i], &fp->fp[i + 1], | |
904 | left * sizeof(struct file *)); | |
905 | } | |
906 | fp->count--; | |
907 | if (!fp->count) { | |
908 | kfree_skb(skb); | |
909 | skb = NULL; | |
910 | } else { | |
911 | __skb_queue_tail(&list, skb); | |
912 | } | |
913 | fput(file); | |
914 | file = NULL; | |
915 | break; | |
916 | } | |
917 | ||
918 | if (!file) | |
919 | break; | |
920 | ||
921 | __skb_queue_tail(&list, skb); | |
922 | ||
923 | skb = skb_dequeue(head); | |
924 | } | |
925 | ||
926 | if (skb_peek(&list)) { | |
927 | spin_lock_irq(&head->lock); | |
928 | while ((skb = __skb_dequeue(&list)) != NULL) | |
929 | __skb_queue_tail(head, skb); | |
930 | spin_unlock_irq(&head->lock); | |
931 | } | |
932 | #else | |
933 | fput(file); | |
934 | #endif | |
935 | } | |
936 | ||
937 | int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, | |
938 | unsigned nr_args, u64 __user *tags) | |
939 | { | |
940 | __s32 __user *fds = (__s32 __user *) arg; | |
941 | struct file *file; | |
942 | int fd, ret; | |
943 | unsigned i; | |
944 | ||
945 | if (ctx->file_data) | |
946 | return -EBUSY; | |
947 | if (!nr_args) | |
948 | return -EINVAL; | |
949 | if (nr_args > IORING_MAX_FIXED_FILES) | |
950 | return -EMFILE; | |
951 | if (nr_args > rlimit(RLIMIT_NOFILE)) | |
952 | return -EMFILE; | |
953 | ret = io_rsrc_node_switch_start(ctx); | |
954 | if (ret) | |
955 | return ret; | |
956 | ret = io_rsrc_data_alloc(ctx, io_rsrc_file_put, tags, nr_args, | |
957 | &ctx->file_data); | |
958 | if (ret) | |
959 | return ret; | |
960 | ||
961 | if (!io_alloc_file_tables(&ctx->file_table, nr_args)) { | |
962 | io_rsrc_data_free(ctx->file_data); | |
963 | ctx->file_data = NULL; | |
964 | return -ENOMEM; | |
965 | } | |
966 | ||
967 | for (i = 0; i < nr_args; i++, ctx->nr_user_files++) { | |
968 | struct io_fixed_file *file_slot; | |
969 | ||
970 | if (fds && copy_from_user(&fd, &fds[i], sizeof(fd))) { | |
971 | ret = -EFAULT; | |
972 | goto fail; | |
973 | } | |
974 | /* allow sparse sets */ | |
975 | if (!fds || fd == -1) { | |
976 | ret = -EINVAL; | |
977 | if (unlikely(*io_get_tag_slot(ctx->file_data, i))) | |
978 | goto fail; | |
979 | continue; | |
980 | } | |
981 | ||
982 | file = fget(fd); | |
983 | ret = -EBADF; | |
984 | if (unlikely(!file)) | |
985 | goto fail; | |
986 | ||
987 | /* | |
988 | * Don't allow io_uring instances to be registered. If UNIX | |
989 | * isn't enabled, then this causes a reference cycle and this | |
990 | * instance can never get freed. If UNIX is enabled we'll | |
991 | * handle it just fine, but there's still no point in allowing | |
992 | * a ring fd as it doesn't support regular read/write anyway. | |
993 | */ | |
994 | if (io_is_uring_fops(file)) { | |
995 | fput(file); | |
996 | goto fail; | |
997 | } | |
998 | ret = io_scm_file_account(ctx, file); | |
999 | if (ret) { | |
1000 | fput(file); | |
1001 | goto fail; | |
1002 | } | |
1003 | file_slot = io_fixed_file_slot(&ctx->file_table, i); | |
1004 | io_fixed_file_set(file_slot, file); | |
1005 | io_file_bitmap_set(&ctx->file_table, i); | |
1006 | } | |
1007 | ||
6e73dffb PB |
1008 | /* default it to the whole table */ |
1009 | io_file_table_set_alloc_range(ctx, 0, ctx->nr_user_files); | |
73572984 JA |
1010 | io_rsrc_node_switch(ctx, NULL); |
1011 | return 0; | |
1012 | fail: | |
1013 | __io_sqe_files_unregister(ctx); | |
1014 | return ret; | |
1015 | } | |
1016 | ||
1017 | static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc) | |
1018 | { | |
1019 | io_buffer_unmap(ctx, &prsrc->buf); | |
1020 | prsrc->buf = NULL; | |
1021 | } | |
1022 | ||
1023 | void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx) | |
1024 | { | |
1025 | unsigned int i; | |
1026 | ||
1027 | for (i = 0; i < ctx->nr_user_bufs; i++) | |
1028 | io_buffer_unmap(ctx, &ctx->user_bufs[i]); | |
1029 | kfree(ctx->user_bufs); | |
1030 | io_rsrc_data_free(ctx->buf_data); | |
1031 | ctx->user_bufs = NULL; | |
1032 | ctx->buf_data = NULL; | |
1033 | ctx->nr_user_bufs = 0; | |
1034 | } | |
1035 | ||
1036 | int io_sqe_buffers_unregister(struct io_ring_ctx *ctx) | |
1037 | { | |
1038 | unsigned nr = ctx->nr_user_bufs; | |
1039 | int ret; | |
1040 | ||
1041 | if (!ctx->buf_data) | |
1042 | return -ENXIO; | |
1043 | ||
1044 | /* | |
1045 | * Quiesce may unlock ->uring_lock, and while it's not held | |
1046 | * prevent new requests using the table. | |
1047 | */ | |
1048 | ctx->nr_user_bufs = 0; | |
1049 | ret = io_rsrc_ref_quiesce(ctx->buf_data, ctx); | |
1050 | ctx->nr_user_bufs = nr; | |
1051 | if (!ret) | |
1052 | __io_sqe_buffers_unregister(ctx); | |
1053 | return ret; | |
1054 | } | |
1055 | ||
1056 | /* | |
1057 | * Not super efficient, but this is just a registration time. And we do cache | |
1058 | * the last compound head, so generally we'll only do a full search if we don't | |
1059 | * match that one. | |
1060 | * | |
1061 | * We check if the given compound head page has already been accounted, to | |
1062 | * avoid double accounting it. This allows us to account the full size of the | |
1063 | * page, not just the constituent pages of a huge page. | |
1064 | */ | |
1065 | static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages, | |
1066 | int nr_pages, struct page *hpage) | |
1067 | { | |
1068 | int i, j; | |
1069 | ||
1070 | /* check current page array */ | |
1071 | for (i = 0; i < nr_pages; i++) { | |
1072 | if (!PageCompound(pages[i])) | |
1073 | continue; | |
1074 | if (compound_head(pages[i]) == hpage) | |
1075 | return true; | |
1076 | } | |
1077 | ||
1078 | /* check previously registered pages */ | |
1079 | for (i = 0; i < ctx->nr_user_bufs; i++) { | |
1080 | struct io_mapped_ubuf *imu = ctx->user_bufs[i]; | |
1081 | ||
1082 | for (j = 0; j < imu->nr_bvecs; j++) { | |
1083 | if (!PageCompound(imu->bvec[j].bv_page)) | |
1084 | continue; | |
1085 | if (compound_head(imu->bvec[j].bv_page) == hpage) | |
1086 | return true; | |
1087 | } | |
1088 | } | |
1089 | ||
1090 | return false; | |
1091 | } | |
1092 | ||
1093 | static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages, | |
1094 | int nr_pages, struct io_mapped_ubuf *imu, | |
1095 | struct page **last_hpage) | |
1096 | { | |
1097 | int i, ret; | |
1098 | ||
1099 | imu->acct_pages = 0; | |
1100 | for (i = 0; i < nr_pages; i++) { | |
1101 | if (!PageCompound(pages[i])) { | |
1102 | imu->acct_pages++; | |
1103 | } else { | |
1104 | struct page *hpage; | |
1105 | ||
1106 | hpage = compound_head(pages[i]); | |
1107 | if (hpage == *last_hpage) | |
1108 | continue; | |
1109 | *last_hpage = hpage; | |
1110 | if (headpage_already_acct(ctx, pages, i, hpage)) | |
1111 | continue; | |
1112 | imu->acct_pages += page_size(hpage) >> PAGE_SHIFT; | |
1113 | } | |
1114 | } | |
1115 | ||
1116 | if (!imu->acct_pages) | |
1117 | return 0; | |
1118 | ||
1119 | ret = io_account_mem(ctx, imu->acct_pages); | |
1120 | if (ret) | |
1121 | imu->acct_pages = 0; | |
1122 | return ret; | |
1123 | } | |
1124 | ||
1125 | struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages) | |
1126 | { | |
1127 | unsigned long start, end, nr_pages; | |
1128 | struct vm_area_struct **vmas = NULL; | |
1129 | struct page **pages = NULL; | |
1130 | int i, pret, ret = -ENOMEM; | |
1131 | ||
1132 | end = (ubuf + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1133 | start = ubuf >> PAGE_SHIFT; | |
1134 | nr_pages = end - start; | |
1135 | ||
1136 | pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL); | |
1137 | if (!pages) | |
1138 | goto done; | |
1139 | ||
1140 | vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *), | |
1141 | GFP_KERNEL); | |
1142 | if (!vmas) | |
1143 | goto done; | |
1144 | ||
1145 | ret = 0; | |
1146 | mmap_read_lock(current->mm); | |
1147 | pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM, | |
1148 | pages, vmas); | |
1149 | if (pret == nr_pages) { | |
1150 | /* don't support file backed memory */ | |
1151 | for (i = 0; i < nr_pages; i++) { | |
1152 | struct vm_area_struct *vma = vmas[i]; | |
1153 | ||
1154 | if (vma_is_shmem(vma)) | |
1155 | continue; | |
1156 | if (vma->vm_file && | |
1157 | !is_file_hugepages(vma->vm_file)) { | |
1158 | ret = -EOPNOTSUPP; | |
1159 | break; | |
1160 | } | |
1161 | } | |
1162 | *npages = nr_pages; | |
1163 | } else { | |
1164 | ret = pret < 0 ? pret : -EFAULT; | |
1165 | } | |
1166 | mmap_read_unlock(current->mm); | |
1167 | if (ret) { | |
1168 | /* | |
1169 | * if we did partial map, or found file backed vmas, | |
1170 | * release any pages we did get | |
1171 | */ | |
1172 | if (pret > 0) | |
1173 | unpin_user_pages(pages, pret); | |
1174 | goto done; | |
1175 | } | |
1176 | ret = 0; | |
1177 | done: | |
1178 | kvfree(vmas); | |
1179 | if (ret < 0) { | |
1180 | kvfree(pages); | |
1181 | pages = ERR_PTR(ret); | |
1182 | } | |
1183 | return pages; | |
1184 | } | |
1185 | ||
1186 | static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov, | |
1187 | struct io_mapped_ubuf **pimu, | |
1188 | struct page **last_hpage) | |
1189 | { | |
1190 | struct io_mapped_ubuf *imu = NULL; | |
1191 | struct page **pages = NULL; | |
1192 | unsigned long off; | |
1193 | size_t size; | |
1194 | int ret, nr_pages, i; | |
1195 | ||
5ff4fdff PB |
1196 | *pimu = ctx->dummy_ubuf; |
1197 | if (!iov->iov_base) | |
73572984 | 1198 | return 0; |
73572984 | 1199 | |
73572984 | 1200 | ret = -ENOMEM; |
73572984 JA |
1201 | pages = io_pin_pages((unsigned long) iov->iov_base, iov->iov_len, |
1202 | &nr_pages); | |
1203 | if (IS_ERR(pages)) { | |
1204 | ret = PTR_ERR(pages); | |
1205 | pages = NULL; | |
1206 | goto done; | |
1207 | } | |
1208 | ||
1209 | imu = kvmalloc(struct_size(imu, bvec, nr_pages), GFP_KERNEL); | |
1210 | if (!imu) | |
1211 | goto done; | |
1212 | ||
1213 | ret = io_buffer_account_pin(ctx, pages, nr_pages, imu, last_hpage); | |
1214 | if (ret) { | |
1215 | unpin_user_pages(pages, nr_pages); | |
1216 | goto done; | |
1217 | } | |
1218 | ||
1219 | off = (unsigned long) iov->iov_base & ~PAGE_MASK; | |
1220 | size = iov->iov_len; | |
1221 | for (i = 0; i < nr_pages; i++) { | |
1222 | size_t vec_len; | |
1223 | ||
1224 | vec_len = min_t(size_t, size, PAGE_SIZE - off); | |
1225 | imu->bvec[i].bv_page = pages[i]; | |
1226 | imu->bvec[i].bv_len = vec_len; | |
1227 | imu->bvec[i].bv_offset = off; | |
1228 | off = 0; | |
1229 | size -= vec_len; | |
1230 | } | |
1231 | /* store original address for later verification */ | |
1232 | imu->ubuf = (unsigned long) iov->iov_base; | |
1233 | imu->ubuf_end = imu->ubuf + iov->iov_len; | |
1234 | imu->nr_bvecs = nr_pages; | |
1235 | *pimu = imu; | |
1236 | ret = 0; | |
1237 | done: | |
1238 | if (ret) | |
1239 | kvfree(imu); | |
1240 | kvfree(pages); | |
1241 | return ret; | |
1242 | } | |
1243 | ||
1244 | static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args) | |
1245 | { | |
1246 | ctx->user_bufs = kcalloc(nr_args, sizeof(*ctx->user_bufs), GFP_KERNEL); | |
1247 | return ctx->user_bufs ? 0 : -ENOMEM; | |
1248 | } | |
1249 | ||
1250 | int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, | |
1251 | unsigned int nr_args, u64 __user *tags) | |
1252 | { | |
1253 | struct page *last_hpage = NULL; | |
1254 | struct io_rsrc_data *data; | |
1255 | int i, ret; | |
1256 | struct iovec iov; | |
1257 | ||
1258 | BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16)); | |
1259 | ||
1260 | if (ctx->user_bufs) | |
1261 | return -EBUSY; | |
1262 | if (!nr_args || nr_args > IORING_MAX_REG_BUFFERS) | |
1263 | return -EINVAL; | |
1264 | ret = io_rsrc_node_switch_start(ctx); | |
1265 | if (ret) | |
1266 | return ret; | |
1267 | ret = io_rsrc_data_alloc(ctx, io_rsrc_buf_put, tags, nr_args, &data); | |
1268 | if (ret) | |
1269 | return ret; | |
1270 | ret = io_buffers_map_alloc(ctx, nr_args); | |
1271 | if (ret) { | |
1272 | io_rsrc_data_free(data); | |
1273 | return ret; | |
1274 | } | |
1275 | ||
1276 | for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) { | |
1277 | if (arg) { | |
1278 | ret = io_copy_iov(ctx, &iov, arg, i); | |
1279 | if (ret) | |
1280 | break; | |
1281 | ret = io_buffer_validate(&iov); | |
1282 | if (ret) | |
1283 | break; | |
1284 | } else { | |
1285 | memset(&iov, 0, sizeof(iov)); | |
1286 | } | |
1287 | ||
1288 | if (!iov.iov_base && *io_get_tag_slot(data, i)) { | |
1289 | ret = -EINVAL; | |
1290 | break; | |
1291 | } | |
1292 | ||
1293 | ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i], | |
1294 | &last_hpage); | |
1295 | if (ret) | |
1296 | break; | |
1297 | } | |
1298 | ||
1299 | WARN_ON_ONCE(ctx->buf_data); | |
1300 | ||
1301 | ctx->buf_data = data; | |
1302 | if (ret) | |
1303 | __io_sqe_buffers_unregister(ctx); | |
1304 | else | |
1305 | io_rsrc_node_switch(ctx, NULL); | |
1306 | return ret; | |
1307 | } | |
c059f785 PB |
1308 | |
1309 | int io_import_fixed(int ddir, struct iov_iter *iter, | |
1310 | struct io_mapped_ubuf *imu, | |
1311 | u64 buf_addr, size_t len) | |
1312 | { | |
1313 | u64 buf_end; | |
1314 | size_t offset; | |
1315 | ||
1316 | if (WARN_ON_ONCE(!imu)) | |
1317 | return -EFAULT; | |
1318 | if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end))) | |
1319 | return -EFAULT; | |
1320 | /* not inside the mapped region */ | |
1321 | if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end)) | |
1322 | return -EFAULT; | |
1323 | ||
1324 | /* | |
1325 | * May not be a start of buffer, set size appropriately | |
1326 | * and advance us to the beginning. | |
1327 | */ | |
1328 | offset = buf_addr - imu->ubuf; | |
1329 | iov_iter_bvec(iter, ddir, imu->bvec, imu->nr_bvecs, offset + len); | |
1330 | ||
1331 | if (offset) { | |
1332 | /* | |
1333 | * Don't use iov_iter_advance() here, as it's really slow for | |
1334 | * using the latter parts of a big fixed buffer - it iterates | |
1335 | * over each segment manually. We can cheat a bit here, because | |
1336 | * we know that: | |
1337 | * | |
1338 | * 1) it's a BVEC iter, we set it up | |
1339 | * 2) all bvecs are PAGE_SIZE in size, except potentially the | |
1340 | * first and last bvec | |
1341 | * | |
1342 | * So just find our index, and adjust the iterator afterwards. | |
1343 | * If the offset is within the first bvec (or the whole first | |
1344 | * bvec, just use iov_iter_advance(). This makes it easier | |
1345 | * since we can just skip the first segment, which may not | |
1346 | * be PAGE_SIZE aligned. | |
1347 | */ | |
1348 | const struct bio_vec *bvec = imu->bvec; | |
1349 | ||
1350 | if (offset <= bvec->bv_len) { | |
1351 | iov_iter_advance(iter, offset); | |
1352 | } else { | |
1353 | unsigned long seg_skip; | |
1354 | ||
1355 | /* skip first vec */ | |
1356 | offset -= bvec->bv_len; | |
1357 | seg_skip = 1 + (offset >> PAGE_SHIFT); | |
1358 | ||
1359 | iter->bvec = bvec + seg_skip; | |
1360 | iter->nr_segs -= seg_skip; | |
1361 | iter->count -= bvec->bv_len + offset; | |
1362 | iter->iov_offset = offset & ~PAGE_MASK; | |
1363 | } | |
1364 | } | |
1365 | ||
1366 | return 0; | |
1367 | } |