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io_uring/rsrc: add lockdep sanity checks
[linux-block.git] / io_uring / rsrc.c
CommitLineData
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
19struct io_rsrc_update {
20 struct file *file;
21 u64 arg;
22 u32 nr_args;
23 u32 offset;
24};
25
26static 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
73572984
JA		 30/* only define max */
31#define IORING_MAX_FIXED_FILES (1U << 20)
32#define IORING_MAX_REG_BUFFERS (1U << 14)
33
6a9ce66f 34int __io_account_mem(struct user_struct *user, unsigned long nr_pages)
73572984
JA		 35{
36 unsigned long page_limit, cur_pages, new_pages;
37
6a9ce66f
PB		 38 if (!nr_pages)
39 return 0;
40
73572984
JA		 41 /* Don't allow more pages than we can safely lock */
42 page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
43
4ccc6db0 44 cur_pages = atomic_long_read(&user->locked_vm);
73572984 45 do {
73572984
JA		 46 new_pages = cur_pages + nr_pages;
47 if (new_pages > page_limit)
48 return -ENOMEM;
4ccc6db0
UB		 49 } while (!atomic_long_try_cmpxchg(&user->locked_vm,
50 &cur_pages, new_pages));
73572984
JA		 51 return 0;
52}
53
54static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
55{
56 if (ctx->user)
57 __io_unaccount_mem(ctx->user, nr_pages);
58
59 if (ctx->mm_account)
60 atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
61}
62
63static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
64{
65 int ret;
66
67 if (ctx->user) {
68 ret = __io_account_mem(ctx->user, nr_pages);
69 if (ret)
70 return ret;
71 }
72
73 if (ctx->mm_account)
74 atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
75
76 return 0;
77}
78
79static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
80 void __user *arg, unsigned index)
81{
82 struct iovec __user *src;
83
84#ifdef CONFIG_COMPAT
85 if (ctx->compat) {
86 struct compat_iovec __user *ciovs;
87 struct compat_iovec ciov;
88
89 ciovs = (struct compat_iovec __user *) arg;
90 if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
91 return -EFAULT;
92
93 dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
94 dst->iov_len = ciov.iov_len;
95 return 0;
96 }
97#endif
98 src = (struct iovec __user *) arg;
99 if (copy_from_user(dst, &src[index], sizeof(*dst)))
100 return -EFAULT;
101 return 0;
102}
103
104static int io_buffer_validate(struct iovec *iov)
105{
106 unsigned long tmp, acct_len = iov->iov_len + (PAGE_SIZE - 1);
107
108 /*
109 * Don't impose further limits on the size and buffer
110 * constraints here, we'll -EINVAL later when IO is
111 * submitted if they are wrong.
112 */
113 if (!iov->iov_base)
114 return iov->iov_len ? -EFAULT : 0;
115 if (!iov->iov_len)
116 return -EFAULT;
117
118 /* arbitrary limit, but we need something */
119 if (iov->iov_len > SZ_1G)
120 return -EFAULT;
121
122 if (check_add_overflow((unsigned long)iov->iov_base, acct_len, &tmp))
123 return -EOVERFLOW;
124
125 return 0;
126}
127
128static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slot)
129{
130 struct io_mapped_ubuf *imu = *slot;
131 unsigned int i;
132
133 if (imu != ctx->dummy_ubuf) {
134 for (i = 0; i < imu->nr_bvecs; i++)
135 unpin_user_page(imu->bvec[i].bv_page);
136 if (imu->acct_pages)
137 io_unaccount_mem(ctx, imu->acct_pages);
138 kvfree(imu);
139 }
140 *slot = NULL;
141}
142
ff7c75ec
PB		 143static void io_rsrc_put_work_one(struct io_rsrc_data *rsrc_data,
144 struct io_rsrc_put *prsrc)
145{
146 struct io_ring_ctx *ctx = rsrc_data->ctx;
147
36b9818a
PB		 148 if (prsrc->tag)
149 io_post_aux_cqe(ctx, prsrc->tag, 0, 0);
ff7c75ec
PB		 150 rsrc_data->do_put(ctx, prsrc);
151}
152
73572984
JA		 153static void __io_rsrc_put_work(struct io_rsrc_node *ref_node)
154{
155 struct io_rsrc_data *rsrc_data = ref_node->rsrc_data;
73572984
JA		 156 struct io_rsrc_put *prsrc, *tmp;
157
ff7c75ec
PB		 158 if (ref_node->inline_items)
159 io_rsrc_put_work_one(rsrc_data, &ref_node->item);
160
c824986c 161 list_for_each_entry_safe(prsrc, tmp, &ref_node->item_list, list) {
73572984 162 list_del(&prsrc->list);
ff7c75ec 163 io_rsrc_put_work_one(rsrc_data, prsrc);
73572984
JA		 164 kfree(prsrc);
165 }
166
9eae8655 167 io_rsrc_node_destroy(rsrc_data->ctx, ref_node);
73572984
JA		 168 if (atomic_dec_and_test(&rsrc_data->refs))
169 complete(&rsrc_data->done);
170}
171
73572984
JA		 172void io_wait_rsrc_data(struct io_rsrc_data *data)
173{
174 if (data && !atomic_dec_and_test(&data->refs))
175 wait_for_completion(&data->done);
176}
177
9eae8655 178void io_rsrc_node_destroy(struct io_ring_ctx *ctx, struct io_rsrc_node *node)
73572984 179{
9eae8655
PB		 180 if (!io_alloc_cache_put(&ctx->rsrc_node_cache, &node->cache))
181 kfree(node);
73572984
JA		 182}
183
ef8ae64f
PB		 184void io_rsrc_node_ref_zero(struct io_rsrc_node *node)
185 __must_hold(&node->rsrc_data->ctx->uring_lock)
73572984 186{
73572984 187 struct io_ring_ctx *ctx = node->rsrc_data->ctx;
73572984 188
73572984 189 node->done = true;
73572984
JA		 190 while (!list_empty(&ctx->rsrc_ref_list)) {
191 node = list_first_entry(&ctx->rsrc_ref_list,
192 struct io_rsrc_node, node);
193 /* recycle ref nodes in order */
194 if (!node->done)
195 break;
73572984 196
36b9818a
PB		 197 list_del(&node->node);
198 __io_rsrc_put_work(node);
d34b1b0b 199 }
73572984
JA		 200}
201
9eae8655 202static struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx)
73572984
JA		 203{
204 struct io_rsrc_node *ref_node;
9eae8655
PB		 205 struct io_cache_entry *entry;
206
207 entry = io_alloc_cache_get(&ctx->rsrc_node_cache);
208 if (entry) {
209 ref_node = container_of(entry, struct io_rsrc_node, cache);
210 } else {
211 ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
212 if (!ref_node)
213 return NULL;
214 }
73572984 215
ef8ae64f 216 ref_node->refs = 1;
73572984 217 INIT_LIST_HEAD(&ref_node->node);
c824986c 218 INIT_LIST_HEAD(&ref_node->item_list);
73572984 219 ref_node->done = false;
ff7c75ec 220 ref_node->inline_items = 0;
73572984
JA		 221 return ref_node;
222}
223
224void io_rsrc_node_switch(struct io_ring_ctx *ctx,
225 struct io_rsrc_data *data_to_kill)
226 __must_hold(&ctx->uring_lock)
227{
228 WARN_ON_ONCE(!ctx->rsrc_backup_node);
229 WARN_ON_ONCE(data_to_kill && !ctx->rsrc_node);
230
73572984
JA		 231 if (data_to_kill) {
232 struct io_rsrc_node *rsrc_node = ctx->rsrc_node;
233
234 rsrc_node->rsrc_data = data_to_kill;
73572984 235 list_add_tail(&rsrc_node->node, &ctx->rsrc_ref_list);
73572984
JA		 236
237 atomic_inc(&data_to_kill->refs);
b8fb5b4f 238 /* put master ref */
1f2c8f61 239 io_put_rsrc_node(ctx, rsrc_node);
73572984
JA		 240 ctx->rsrc_node = NULL;
241 }
242
243 if (!ctx->rsrc_node) {
244 ctx->rsrc_node = ctx->rsrc_backup_node;
245 ctx->rsrc_backup_node = NULL;
246 }
247}
248
249int io_rsrc_node_switch_start(struct io_ring_ctx *ctx)
250{
251 if (ctx->rsrc_backup_node)
252 return 0;
9eae8655 253 ctx->rsrc_backup_node = io_rsrc_node_alloc(ctx);
73572984
JA		 254 return ctx->rsrc_backup_node ? 0 : -ENOMEM;
255}
256
257__cold static int io_rsrc_ref_quiesce(struct io_rsrc_data *data,
258 struct io_ring_ctx *ctx)
259{
260 int ret;
261
262 /* As we may drop ->uring_lock, other task may have started quiesce */
263 if (data->quiesce)
264 return -ENXIO;
77e3202a
PB		 265 ret = io_rsrc_node_switch_start(ctx);
266 if (ret)
267 return ret;
268 io_rsrc_node_switch(ctx, data);
269
270 /* kill initial ref, already quiesced if zero */
271 if (atomic_dec_and_test(&data->refs))
272 return 0;
73572984
JA		 273
274 data->quiesce = true;
77e3202a 275 mutex_unlock(&ctx->uring_lock);
73572984 276 do {
ef67fcb4 277 ret = io_run_task_work_sig(ctx);
77e3202a
PB		 278 if (ret < 0) {
279 atomic_inc(&data->refs);
280 /* wait for all works potentially completing data->done */
77e3202a
PB		 281 reinit_completion(&data->done);
282 mutex_lock(&ctx->uring_lock);
283 break;
284 }
ef67fcb4 285
73572984
JA		 286 ret = wait_for_completion_interruptible(&data->done);
287 if (!ret) {
288 mutex_lock(&ctx->uring_lock);
0ced756f 289 if (atomic_read(&data->refs) <= 0)
73572984 290 break;
0ced756f
PB		 291 /*
292 * it has been revived by another thread while
293 * we were unlocked
294 */
295 mutex_unlock(&ctx->uring_lock);
73572984 296 }
77e3202a 297 } while (1);
73572984
JA		 298 data->quiesce = false;
299
300 return ret;
301}
302
303static void io_free_page_table(void **table, size_t size)
304{
305 unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
306
307 for (i = 0; i < nr_tables; i++)
308 kfree(table[i]);
309 kfree(table);
310}
311
312static void io_rsrc_data_free(struct io_rsrc_data *data)
313{
314 size_t size = data->nr * sizeof(data->tags[0][0]);
315
316 if (data->tags)
317 io_free_page_table((void **)data->tags, size);
318 kfree(data);
319}
320
321static __cold void **io_alloc_page_table(size_t size)
322{
323 unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
324 size_t init_size = size;
325 void **table;
326
327 table = kcalloc(nr_tables, sizeof(*table), GFP_KERNEL_ACCOUNT);
328 if (!table)
329 return NULL;
330
331 for (i = 0; i < nr_tables; i++) {
332 unsigned int this_size = min_t(size_t, size, PAGE_SIZE);
333
334 table[i] = kzalloc(this_size, GFP_KERNEL_ACCOUNT);
335 if (!table[i]) {
336 io_free_page_table(table, init_size);
337 return NULL;
338 }
339 size -= this_size;
340 }
341 return table;
342}
343
344__cold static int io_rsrc_data_alloc(struct io_ring_ctx *ctx,
345 rsrc_put_fn *do_put, u64 __user *utags,
346 unsigned nr, struct io_rsrc_data **pdata)
347{
348 struct io_rsrc_data *data;
6acd352d 349 int ret = 0;
73572984
JA		 350 unsigned i;
351
352 data = kzalloc(sizeof(*data), GFP_KERNEL);
353 if (!data)
354 return -ENOMEM;
355 data->tags = (u64 **)io_alloc_page_table(nr * sizeof(data->tags[0][0]));
356 if (!data->tags) {
357 kfree(data);
358 return -ENOMEM;
359 }
360
361 data->nr = nr;
362 data->ctx = ctx;
363 data->do_put = do_put;
364 if (utags) {
365 ret = -EFAULT;
366 for (i = 0; i < nr; i++) {
367 u64 *tag_slot = io_get_tag_slot(data, i);
368
369 if (copy_from_user(tag_slot, &utags[i],
370 sizeof(*tag_slot)))
371 goto fail;
372 }
373 }
374
375 atomic_set(&data->refs, 1);
376 init_completion(&data->done);
377 *pdata = data;
378 return 0;
379fail:
380 io_rsrc_data_free(data);
381 return ret;
382}
383
384static int __io_sqe_files_update(struct io_ring_ctx *ctx,
385 struct io_uring_rsrc_update2 *up,
386 unsigned nr_args)
387{
388 u64 __user *tags = u64_to_user_ptr(up->tags);
389 __s32 __user *fds = u64_to_user_ptr(up->data);
390 struct io_rsrc_data *data = ctx->file_data;
391 struct io_fixed_file *file_slot;
392 struct file *file;
393 int fd, i, err = 0;
394 unsigned int done;
395 bool needs_switch = false;
396
397 if (!ctx->file_data)
398 return -ENXIO;
399 if (up->offset + nr_args > ctx->nr_user_files)
400 return -EINVAL;
401
402 for (done = 0; done < nr_args; done++) {
403 u64 tag = 0;
404
405 if ((tags && copy_from_user(&tag, &tags[done], sizeof(tag))) ||
406 copy_from_user(&fd, &fds[done], sizeof(fd))) {
407 err = -EFAULT;
408 break;
409 }
410 if ((fd == IORING_REGISTER_FILES_SKIP || fd == -1) && tag) {
411 err = -EINVAL;
412 break;
413 }
414 if (fd == IORING_REGISTER_FILES_SKIP)
415 continue;
416
417 i = array_index_nospec(up->offset + done, ctx->nr_user_files);
418 file_slot = io_fixed_file_slot(&ctx->file_table, i);
419
420 if (file_slot->file_ptr) {
421 file = (struct file *)(file_slot->file_ptr & FFS_MASK);
422 err = io_queue_rsrc_removal(data, i, ctx->rsrc_node, file);
423 if (err)
424 break;
425 file_slot->file_ptr = 0;
426 io_file_bitmap_clear(&ctx->file_table, i);
427 needs_switch = true;
428 }
429 if (fd != -1) {
430 file = fget(fd);
431 if (!file) {
432 err = -EBADF;
433 break;
434 }
435 /*
436 * Don't allow io_uring instances to be registered. If
437 * UNIX isn't enabled, then this causes a reference
438 * cycle and this instance can never get freed. If UNIX
439 * is enabled we'll handle it just fine, but there's
440 * still no point in allowing a ring fd as it doesn't
441 * support regular read/write anyway.
442 */
443 if (io_is_uring_fops(file)) {
444 fput(file);
445 err = -EBADF;
446 break;
447 }
448 err = io_scm_file_account(ctx, file);
449 if (err) {
450 fput(file);
451 break;
452 }
453 *io_get_tag_slot(data, i) = tag;
454 io_fixed_file_set(file_slot, file);
455 io_file_bitmap_set(&ctx->file_table, i);
456 }
457 }
458
459 if (needs_switch)
460 io_rsrc_node_switch(ctx, data);
461 return done ? done : err;
462}
463
464static int __io_sqe_buffers_update(struct io_ring_ctx *ctx,
465 struct io_uring_rsrc_update2 *up,
466 unsigned int nr_args)
467{
468 u64 __user *tags = u64_to_user_ptr(up->tags);
469 struct iovec iov, __user *iovs = u64_to_user_ptr(up->data);
470 struct page *last_hpage = NULL;
471 bool needs_switch = false;
472 __u32 done;
473 int i, err;
474
475 if (!ctx->buf_data)
476 return -ENXIO;
477 if (up->offset + nr_args > ctx->nr_user_bufs)
478 return -EINVAL;
479
480 for (done = 0; done < nr_args; done++) {
481 struct io_mapped_ubuf *imu;
482 int offset = up->offset + done;
483 u64 tag = 0;
484
485 err = io_copy_iov(ctx, &iov, iovs, done);
486 if (err)
487 break;
488 if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) {
489 err = -EFAULT;
490 break;
491 }
492 err = io_buffer_validate(&iov);
493 if (err)
494 break;
495 if (!iov.iov_base && tag) {
496 err = -EINVAL;
497 break;
498 }
499 err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage);
500 if (err)
501 break;
502
503 i = array_index_nospec(offset, ctx->nr_user_bufs);
504 if (ctx->user_bufs[i] != ctx->dummy_ubuf) {
505 err = io_queue_rsrc_removal(ctx->buf_data, i,
506 ctx->rsrc_node, ctx->user_bufs[i]);
507 if (unlikely(err)) {
508 io_buffer_unmap(ctx, &imu);
509 break;
510 }
5ff4fdff 511 ctx->user_bufs[i] = ctx->dummy_ubuf;
73572984
JA		 512 needs_switch = true;
513 }
514
515 ctx->user_bufs[i] = imu;
516 *io_get_tag_slot(ctx->buf_data, offset) = tag;
517 }
518
519 if (needs_switch)
520 io_rsrc_node_switch(ctx, ctx->buf_data);
521 return done ? done : err;
522}
523
524static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type,
525 struct io_uring_rsrc_update2 *up,
526 unsigned nr_args)
527{
528 __u32 tmp;
529 int err;
530
531 if (check_add_overflow(up->offset, nr_args, &tmp))
532 return -EOVERFLOW;
533 err = io_rsrc_node_switch_start(ctx);
534 if (err)
535 return err;
536
537 switch (type) {
538 case IORING_RSRC_FILE:
539 return __io_sqe_files_update(ctx, up, nr_args);
540 case IORING_RSRC_BUFFER:
541 return __io_sqe_buffers_update(ctx, up, nr_args);
542 }
543 return -EINVAL;
544}
545
546int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
547 unsigned nr_args)
548{
549 struct io_uring_rsrc_update2 up;
550
551 if (!nr_args)
552 return -EINVAL;
553 memset(&up, 0, sizeof(up));
554 if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update)))
555 return -EFAULT;
556 if (up.resv || up.resv2)
557 return -EINVAL;
558 return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args);
559}
560
561int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
562 unsigned size, unsigned type)
563{
564 struct io_uring_rsrc_update2 up;
565
566 if (size != sizeof(up))
567 return -EINVAL;
568 if (copy_from_user(&up, arg, sizeof(up)))
569 return -EFAULT;
570 if (!up.nr || up.resv || up.resv2)
571 return -EINVAL;
572 return __io_register_rsrc_update(ctx, type, &up, up.nr);
573}
574
575__cold int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
576 unsigned int size, unsigned int type)
577{
578 struct io_uring_rsrc_register rr;
579
580 /* keep it extendible */
581 if (size != sizeof(rr))
582 return -EINVAL;
583
584 memset(&rr, 0, sizeof(rr));
585 if (copy_from_user(&rr, arg, size))
586 return -EFAULT;
587 if (!rr.nr || rr.resv2)
588 return -EINVAL;
589 if (rr.flags & ~IORING_RSRC_REGISTER_SPARSE)
590 return -EINVAL;
591
592 switch (type) {
593 case IORING_RSRC_FILE:
594 if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data)
595 break;
596 return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data),
597 rr.nr, u64_to_user_ptr(rr.tags));
598 case IORING_RSRC_BUFFER:
599 if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data)
600 break;
601 return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data),
602 rr.nr, u64_to_user_ptr(rr.tags));
603 }
604 return -EINVAL;
605}
606
d9808ceb 607int io_files_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
73572984 608{
f2ccb5ae 609 struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update);
73572984
JA		 610
611 if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
612 return -EINVAL;
613 if (sqe->rw_flags || sqe->splice_fd_in)
614 return -EINVAL;
615
616 up->offset = READ_ONCE(sqe->off);
617 up->nr_args = READ_ONCE(sqe->len);
618 if (!up->nr_args)
619 return -EINVAL;
620 up->arg = READ_ONCE(sqe->addr);
621 return 0;
622}
623
624static int io_files_update_with_index_alloc(struct io_kiocb *req,
625 unsigned int issue_flags)
626{
f2ccb5ae 627 struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update);
73572984
JA		 628 __s32 __user *fds = u64_to_user_ptr(up->arg);
629 unsigned int done;
630 struct file *file;
631 int ret, fd;
632
633 if (!req->ctx->file_data)
634 return -ENXIO;
635
636 for (done = 0; done < up->nr_args; done++) {
637 if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
638 ret = -EFAULT;
639 break;
640 }
641
642 file = fget(fd);
643 if (!file) {
644 ret = -EBADF;
645 break;
646 }
647 ret = io_fixed_fd_install(req, issue_flags, file,
648 IORING_FILE_INDEX_ALLOC);
649 if (ret < 0)
650 break;
651 if (copy_to_user(&fds[done], &ret, sizeof(ret))) {
f110ed84 652 __io_close_fixed(req->ctx, issue_flags, ret);
73572984
JA		 653 ret = -EFAULT;
654 break;
655 }
656 }
657
658 if (done)
659 return done;
660 return ret;
661}
662
d9808ceb 663int io_files_update(struct io_kiocb *req, unsigned int issue_flags)
73572984 664{
f2ccb5ae 665 struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update);
73572984
JA		 666 struct io_ring_ctx *ctx = req->ctx;
667 struct io_uring_rsrc_update2 up2;
668 int ret;
669
670 up2.offset = up->offset;
671 up2.data = up->arg;
672 up2.nr = 0;
673 up2.tags = 0;
674 up2.resv = 0;
675 up2.resv2 = 0;
676
677 if (up->offset == IORING_FILE_INDEX_ALLOC) {
678 ret = io_files_update_with_index_alloc(req, issue_flags);
679 } else {
680 io_ring_submit_lock(ctx, issue_flags);
681 ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE,
682 &up2, up->nr_args);
683 io_ring_submit_unlock(ctx, issue_flags);
684 }
685
686 if (ret < 0)
687 req_set_fail(req);
688 io_req_set_res(req, ret, 0);
689 return IOU_OK;
690}
691
692int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx,
693 struct io_rsrc_node *node, void *rsrc)
694{
695 u64 *tag_slot = io_get_tag_slot(data, idx);
696 struct io_rsrc_put *prsrc;
ff7c75ec 697 bool inline_item = true;
73572984 698
ff7c75ec
PB		 699 if (!node->inline_items) {
700 prsrc = &node->item;
701 node->inline_items++;
702 } else {
703 prsrc = kzalloc(sizeof(*prsrc), GFP_KERNEL);
704 if (!prsrc)
705 return -ENOMEM;
706 inline_item = false;
707 }
73572984
JA		 708
709 prsrc->tag = *tag_slot;
710 *tag_slot = 0;
711 prsrc->rsrc = rsrc;
ff7c75ec
PB		 712 if (!inline_item)
713 list_add(&prsrc->list, &node->item_list);
73572984
JA		 714 return 0;
715}
716
717void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
718{
73572984
JA		 719 int i;
720
721 for (i = 0; i < ctx->nr_user_files; i++) {
722 struct file *file = io_file_from_index(&ctx->file_table, i);
723
38eddb2c
PB		 724 /* skip scm accounted files, they'll be freed by ->ring_sock */
725 if (!file || io_file_need_scm(file))
73572984
JA		 726 continue;
727 io_file_bitmap_clear(&ctx->file_table, i);
728 fput(file);
729 }
73572984
JA		 730
731#if defined(CONFIG_UNIX)
732 if (ctx->ring_sock) {
733 struct sock *sock = ctx->ring_sock->sk;
734 struct sk_buff *skb;
735
736 while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
737 kfree_skb(skb);
738 }
739#endif
740 io_free_file_tables(&ctx->file_table);
02a4d923 741 io_file_table_set_alloc_range(ctx, 0, 0);
73572984
JA		 742 io_rsrc_data_free(ctx->file_data);
743 ctx->file_data = NULL;
744 ctx->nr_user_files = 0;
745}
746
747int io_sqe_files_unregister(struct io_ring_ctx *ctx)
748{
749 unsigned nr = ctx->nr_user_files;
750 int ret;
751
752 if (!ctx->file_data)
753 return -ENXIO;
754
755 /*
756 * Quiesce may unlock ->uring_lock, and while it's not held
757 * prevent new requests using the table.
758 */
759 ctx->nr_user_files = 0;
760 ret = io_rsrc_ref_quiesce(ctx->file_data, ctx);
761 ctx->nr_user_files = nr;
762 if (!ret)
763 __io_sqe_files_unregister(ctx);
764 return ret;
765}
766
767/*
768 * Ensure the UNIX gc is aware of our file set, so we are certain that
769 * the io_uring can be safely unregistered on process exit, even if we have
770 * loops in the file referencing. We account only files that can hold other
771 * files because otherwise they can't form a loop and so are not interesting
772 * for GC.
773 */
774int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
775{
776#if defined(CONFIG_UNIX)
777 struct sock *sk = ctx->ring_sock->sk;
778 struct sk_buff_head *head = &sk->sk_receive_queue;
779 struct scm_fp_list *fpl;
780 struct sk_buff *skb;
781
782 if (likely(!io_file_need_scm(file)))
783 return 0;
784
785 /*
786 * See if we can merge this file into an existing skb SCM_RIGHTS
787 * file set. If there's no room, fall back to allocating a new skb
788 * and filling it in.
789 */
790 spin_lock_irq(&head->lock);
791 skb = skb_peek(head);
792 if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)
793 __skb_unlink(skb, head);
794 else
795 skb = NULL;
796 spin_unlock_irq(&head->lock);
797
798 if (!skb) {
799 fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
800 if (!fpl)
801 return -ENOMEM;
802
803 skb = alloc_skb(0, GFP_KERNEL);
804 if (!skb) {
805 kfree(fpl);
806 return -ENOMEM;
807 }
808
809 fpl->user = get_uid(current_user());
810 fpl->max = SCM_MAX_FD;
811 fpl->count = 0;
812
813 UNIXCB(skb).fp = fpl;
814 skb->sk = sk;
0091bfc8 815 skb->scm_io_uring = 1;
73572984
JA		 816 skb->destructor = unix_destruct_scm;
817 refcount_add(skb->truesize, &sk->sk_wmem_alloc);
818 }
819
820 fpl = UNIXCB(skb).fp;
821 fpl->fp[fpl->count++] = get_file(file);
822 unix_inflight(fpl->user, file);
823 skb_queue_head(head, skb);
824 fput(file);
825#endif
826 return 0;
827}
828
829static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
830{
831 struct file *file = prsrc->file;
832#if defined(CONFIG_UNIX)
833 struct sock *sock = ctx->ring_sock->sk;
834 struct sk_buff_head list, *head = &sock->sk_receive_queue;
835 struct sk_buff *skb;
836 int i;
837
838 if (!io_file_need_scm(file)) {
839 fput(file);
840 return;
841 }
842
843 __skb_queue_head_init(&list);
844
845 /*
846 * Find the skb that holds this file in its SCM_RIGHTS. When found,
847 * remove this entry and rearrange the file array.
848 */
849 skb = skb_dequeue(head);
850 while (skb) {
851 struct scm_fp_list *fp;
852
853 fp = UNIXCB(skb).fp;
854 for (i = 0; i < fp->count; i++) {
855 int left;
856
857 if (fp->fp[i] != file)
858 continue;
859
860 unix_notinflight(fp->user, fp->fp[i]);
861 left = fp->count - 1 - i;
862 if (left) {
863 memmove(&fp->fp[i], &fp->fp[i + 1],
864 left * sizeof(struct file *));
865 }
866 fp->count--;
867 if (!fp->count) {
868 kfree_skb(skb);
869 skb = NULL;
870 } else {
871 __skb_queue_tail(&list, skb);
872 }
873 fput(file);
874 file = NULL;
875 break;
876 }
877
878 if (!file)
879 break;
880
881 __skb_queue_tail(&list, skb);
882
883 skb = skb_dequeue(head);
884 }
885
886 if (skb_peek(&list)) {
887 spin_lock_irq(&head->lock);
888 while ((skb = __skb_dequeue(&list)) != NULL)
889 __skb_queue_tail(head, skb);
890 spin_unlock_irq(&head->lock);
891 }
892#else
893 fput(file);
894#endif
895}
896
897int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
898 unsigned nr_args, u64 __user *tags)
899{
900 __s32 __user *fds = (__s32 __user *) arg;
901 struct file *file;
902 int fd, ret;
903 unsigned i;
904
905 if (ctx->file_data)
906 return -EBUSY;
907 if (!nr_args)
908 return -EINVAL;
909 if (nr_args > IORING_MAX_FIXED_FILES)
910 return -EMFILE;
911 if (nr_args > rlimit(RLIMIT_NOFILE))
912 return -EMFILE;
913 ret = io_rsrc_node_switch_start(ctx);
914 if (ret)
915 return ret;
916 ret = io_rsrc_data_alloc(ctx, io_rsrc_file_put, tags, nr_args,
917 &ctx->file_data);
918 if (ret)
919 return ret;
920
921 if (!io_alloc_file_tables(&ctx->file_table, nr_args)) {
922 io_rsrc_data_free(ctx->file_data);
923 ctx->file_data = NULL;
924 return -ENOMEM;
925 }
926
927 for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
928 struct io_fixed_file *file_slot;
929
930 if (fds && copy_from_user(&fd, &fds[i], sizeof(fd))) {
931 ret = -EFAULT;
932 goto fail;
933 }
934 /* allow sparse sets */
935 if (!fds || fd == -1) {
936 ret = -EINVAL;
937 if (unlikely(*io_get_tag_slot(ctx->file_data, i)))
938 goto fail;
939 continue;
940 }
941
942 file = fget(fd);
943 ret = -EBADF;
944 if (unlikely(!file))
945 goto fail;
946
947 /*
948 * Don't allow io_uring instances to be registered. If UNIX
949 * isn't enabled, then this causes a reference cycle and this
950 * instance can never get freed. If UNIX is enabled we'll
951 * handle it just fine, but there's still no point in allowing
952 * a ring fd as it doesn't support regular read/write anyway.
953 */
954 if (io_is_uring_fops(file)) {
955 fput(file);
956 goto fail;
957 }
958 ret = io_scm_file_account(ctx, file);
959 if (ret) {
960 fput(file);
961 goto fail;
962 }
963 file_slot = io_fixed_file_slot(&ctx->file_table, i);
964 io_fixed_file_set(file_slot, file);
965 io_file_bitmap_set(&ctx->file_table, i);
966 }
967
6e73dffb
PB		 968 /* default it to the whole table */
969 io_file_table_set_alloc_range(ctx, 0, ctx->nr_user_files);
73572984
JA		 970 io_rsrc_node_switch(ctx, NULL);
971 return 0;
972fail:
973 __io_sqe_files_unregister(ctx);
974 return ret;
975}
976
977static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
978{
979 io_buffer_unmap(ctx, &prsrc->buf);
980 prsrc->buf = NULL;
981}
982
983void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
984{
985 unsigned int i;
986
987 for (i = 0; i < ctx->nr_user_bufs; i++)
988 io_buffer_unmap(ctx, &ctx->user_bufs[i]);
989 kfree(ctx->user_bufs);
990 io_rsrc_data_free(ctx->buf_data);
991 ctx->user_bufs = NULL;
992 ctx->buf_data = NULL;
993 ctx->nr_user_bufs = 0;
994}
995
996int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
997{
998 unsigned nr = ctx->nr_user_bufs;
999 int ret;
1000
1001 if (!ctx->buf_data)
1002 return -ENXIO;
1003
1004 /*
1005 * Quiesce may unlock ->uring_lock, and while it's not held
1006 * prevent new requests using the table.
1007 */
1008 ctx->nr_user_bufs = 0;
1009 ret = io_rsrc_ref_quiesce(ctx->buf_data, ctx);
1010 ctx->nr_user_bufs = nr;
1011 if (!ret)
1012 __io_sqe_buffers_unregister(ctx);
1013 return ret;
1014}
1015
1016/*
1017 * Not super efficient, but this is just a registration time. And we do cache
1018 * the last compound head, so generally we'll only do a full search if we don't
1019 * match that one.
1020 *
1021 * We check if the given compound head page has already been accounted, to
1022 * avoid double accounting it. This allows us to account the full size of the
1023 * page, not just the constituent pages of a huge page.
1024 */
1025static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
1026 int nr_pages, struct page *hpage)
1027{
1028 int i, j;
1029
1030 /* check current page array */
1031 for (i = 0; i < nr_pages; i++) {
1032 if (!PageCompound(pages[i]))
1033 continue;
1034 if (compound_head(pages[i]) == hpage)
1035 return true;
1036 }
1037
1038 /* check previously registered pages */
1039 for (i = 0; i < ctx->nr_user_bufs; i++) {
1040 struct io_mapped_ubuf *imu = ctx->user_bufs[i];
1041
1042 for (j = 0; j < imu->nr_bvecs; j++) {
1043 if (!PageCompound(imu->bvec[j].bv_page))
1044 continue;
1045 if (compound_head(imu->bvec[j].bv_page) == hpage)
1046 return true;
1047 }
1048 }
1049
1050 return false;
1051}
1052
1053static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
1054 int nr_pages, struct io_mapped_ubuf *imu,
1055 struct page **last_hpage)
1056{
1057 int i, ret;
1058
1059 imu->acct_pages = 0;
1060 for (i = 0; i < nr_pages; i++) {
1061 if (!PageCompound(pages[i])) {
1062 imu->acct_pages++;
1063 } else {
1064 struct page *hpage;
1065
1066 hpage = compound_head(pages[i]);
1067 if (hpage == *last_hpage)
1068 continue;
1069 *last_hpage = hpage;
1070 if (headpage_already_acct(ctx, pages, i, hpage))
1071 continue;
1072 imu->acct_pages += page_size(hpage) >> PAGE_SHIFT;
1073 }
1074 }
1075
1076 if (!imu->acct_pages)
1077 return 0;
1078
1079 ret = io_account_mem(ctx, imu->acct_pages);
1080 if (ret)
1081 imu->acct_pages = 0;
1082 return ret;
1083}
1084
1085struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages)
1086{
1087 unsigned long start, end, nr_pages;
1088 struct vm_area_struct **vmas = NULL;
1089 struct page **pages = NULL;
1090 int i, pret, ret = -ENOMEM;
1091
1092 end = (ubuf + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
1093 start = ubuf >> PAGE_SHIFT;
1094 nr_pages = end - start;
1095
1096 pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
1097 if (!pages)
1098 goto done;
1099
1100 vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *),
1101 GFP_KERNEL);
1102 if (!vmas)
1103 goto done;
1104
1105 ret = 0;
1106 mmap_read_lock(current->mm);
1107 pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
1108 pages, vmas);
1109 if (pret == nr_pages) {
edd47826
PB		 1110 struct file *file = vmas[0]->vm_file;
1111
73572984
JA		 1112 /* don't support file backed memory */
1113 for (i = 0; i < nr_pages; i++) {
edd47826
PB		 1114 if (vmas[i]->vm_file != file) {
1115 ret = -EINVAL;
1116 break;
1117 }
1118 if (!file)
73572984 1119 continue;
edd47826 1120 if (!vma_is_shmem(vmas[i]) && !is_file_hugepages(file)) {
73572984
JA		 1121 ret = -EOPNOTSUPP;
1122 break;
1123 }
1124 }
1125 *npages = nr_pages;
1126 } else {
1127 ret = pret < 0 ? pret : -EFAULT;
1128 }
1129 mmap_read_unlock(current->mm);
1130 if (ret) {
1131 /*
1132 * if we did partial map, or found file backed vmas,
1133 * release any pages we did get
1134 */
1135 if (pret > 0)
1136 unpin_user_pages(pages, pret);
1137 goto done;
1138 }
1139 ret = 0;
1140done:
1141 kvfree(vmas);
1142 if (ret < 0) {
1143 kvfree(pages);
1144 pages = ERR_PTR(ret);
1145 }
1146 return pages;
1147}
1148
1149static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
1150 struct io_mapped_ubuf **pimu,
1151 struct page **last_hpage)
1152{
1153 struct io_mapped_ubuf *imu = NULL;
1154 struct page **pages = NULL;
1155 unsigned long off;
1156 size_t size;
1157 int ret, nr_pages, i;
977bc873 1158 struct folio *folio = NULL;
73572984 1159
5ff4fdff
PB		 1160 *pimu = ctx->dummy_ubuf;
1161 if (!iov->iov_base)
73572984 1162 return 0;
73572984 1163
73572984 1164 ret = -ENOMEM;
73572984
JA		 1165 pages = io_pin_pages((unsigned long) iov->iov_base, iov->iov_len,
1166 &nr_pages);
1167 if (IS_ERR(pages)) {
1168 ret = PTR_ERR(pages);
1169 pages = NULL;
1170 goto done;
1171 }
1172
57bebf80
PB		 1173 /* If it's a huge page, try to coalesce them into a single bvec entry */
1174 if (nr_pages > 1) {
1175 folio = page_folio(pages[0]);
1176 for (i = 1; i < nr_pages; i++) {
1177 if (page_folio(pages[i]) != folio) {
1178 folio = NULL;
1179 break;
1180 }
1181 }
1182 if (folio) {
d2acf789
PB		 1183 /*
1184 * The pages are bound to the folio, it doesn't
1185 * actually unpin them but drops all but one reference,
1186 * which is usually put down by io_buffer_unmap().
1187 * Note, needs a better helper.
1188 */
1189 unpin_user_pages(&pages[1], nr_pages - 1);
57bebf80
PB		 1190 nr_pages = 1;
1191 }
1192 }
1193
73572984
JA		 1194 imu = kvmalloc(struct_size(imu, bvec, nr_pages), GFP_KERNEL);
1195 if (!imu)
1196 goto done;
1197
1198 ret = io_buffer_account_pin(ctx, pages, nr_pages, imu, last_hpage);
1199 if (ret) {
1200 unpin_user_pages(pages, nr_pages);
1201 goto done;
1202 }
1203
1204 off = (unsigned long) iov->iov_base & ~PAGE_MASK;
1205 size = iov->iov_len;
57bebf80
PB		 1206 /* store original address for later verification */
1207 imu->ubuf = (unsigned long) iov->iov_base;
1208 imu->ubuf_end = imu->ubuf + iov->iov_len;
1209 imu->nr_bvecs = nr_pages;
1210 *pimu = imu;
1211 ret = 0;
1212
1213 if (folio) {
1214 bvec_set_page(&imu->bvec[0], pages[0], size, off);
1215 goto done;
1216 }
73572984
JA		 1217 for (i = 0; i < nr_pages; i++) {
1218 size_t vec_len;
1219
1220 vec_len = min_t(size_t, size, PAGE_SIZE - off);
cc342a21 1221 bvec_set_page(&imu->bvec[i], pages[i], vec_len, off);
73572984
JA		 1222 off = 0;
1223 size -= vec_len;
1224 }
73572984
JA		 1225done:
1226 if (ret)
1227 kvfree(imu);
1228 kvfree(pages);
1229 return ret;
1230}
1231
1232static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args)
1233{
1234 ctx->user_bufs = kcalloc(nr_args, sizeof(*ctx->user_bufs), GFP_KERNEL);
1235 return ctx->user_bufs ? 0 : -ENOMEM;
1236}
1237
1238int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
1239 unsigned int nr_args, u64 __user *tags)
1240{
1241 struct page *last_hpage = NULL;
1242 struct io_rsrc_data *data;
1243 int i, ret;
1244 struct iovec iov;
1245
1246 BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16));
1247
1248 if (ctx->user_bufs)
1249 return -EBUSY;
1250 if (!nr_args || nr_args > IORING_MAX_REG_BUFFERS)
1251 return -EINVAL;
1252 ret = io_rsrc_node_switch_start(ctx);
1253 if (ret)
1254 return ret;
1255 ret = io_rsrc_data_alloc(ctx, io_rsrc_buf_put, tags, nr_args, &data);
1256 if (ret)
1257 return ret;
1258 ret = io_buffers_map_alloc(ctx, nr_args);
1259 if (ret) {
1260 io_rsrc_data_free(data);
1261 return ret;
1262 }
1263
1264 for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) {
1265 if (arg) {
1266 ret = io_copy_iov(ctx, &iov, arg, i);
1267 if (ret)
1268 break;
1269 ret = io_buffer_validate(&iov);
1270 if (ret)
1271 break;
1272 } else {
1273 memset(&iov, 0, sizeof(iov));
1274 }
1275
1276 if (!iov.iov_base && *io_get_tag_slot(data, i)) {
1277 ret = -EINVAL;
1278 break;
1279 }
1280
1281 ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i],
1282 &last_hpage);
1283 if (ret)
1284 break;
1285 }
1286
1287 WARN_ON_ONCE(ctx->buf_data);
1288
1289 ctx->buf_data = data;
1290 if (ret)
1291 __io_sqe_buffers_unregister(ctx);
1292 else
1293 io_rsrc_node_switch(ctx, NULL);
1294 return ret;
1295}
c059f785
PB		 1296
1297int io_import_fixed(int ddir, struct iov_iter *iter,
1298 struct io_mapped_ubuf *imu,
1299 u64 buf_addr, size_t len)
1300{
1301 u64 buf_end;
1302 size_t offset;
1303
1304 if (WARN_ON_ONCE(!imu))
1305 return -EFAULT;
1306 if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end)))
1307 return -EFAULT;
1308 /* not inside the mapped region */
1309 if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end))
1310 return -EFAULT;
1311
1312 /*
6bf65a1b 1313 * Might not be a start of buffer, set size appropriately
c059f785
PB		 1314 * and advance us to the beginning.
1315 */
1316 offset = buf_addr - imu->ubuf;
1317 iov_iter_bvec(iter, ddir, imu->bvec, imu->nr_bvecs, offset + len);
1318
1319 if (offset) {
1320 /*
1321 * Don't use iov_iter_advance() here, as it's really slow for
1322 * using the latter parts of a big fixed buffer - it iterates
1323 * over each segment manually. We can cheat a bit here, because
1324 * we know that:
1325 *
1326 * 1) it's a BVEC iter, we set it up
1327 * 2) all bvecs are PAGE_SIZE in size, except potentially the
1328 * first and last bvec
1329 *
1330 * So just find our index, and adjust the iterator afterwards.
1331 * If the offset is within the first bvec (or the whole first
1332 * bvec, just use iov_iter_advance(). This makes it easier
1333 * since we can just skip the first segment, which may not
1334 * be PAGE_SIZE aligned.
1335 */
1336 const struct bio_vec *bvec = imu->bvec;
1337
1338 if (offset <= bvec->bv_len) {
57bebf80
PB		 1339 /*
1340 * Note, huge pages buffers consists of one large
1341 * bvec entry and should always go this way. The other
1342 * branch doesn't expect non PAGE_SIZE'd chunks.
1343 */
b000ae0e
PB		 1344 iter->bvec = bvec;
1345 iter->nr_segs = bvec->bv_len;
1346 iter->count -= offset;
1347 iter->iov_offset = offset;
c059f785
PB		 1348 } else {
1349 unsigned long seg_skip;
1350
1351 /* skip first vec */
1352 offset -= bvec->bv_len;
1353 seg_skip = 1 + (offset >> PAGE_SHIFT);
1354
1355 iter->bvec = bvec + seg_skip;
1356 iter->nr_segs -= seg_skip;
1357 iter->count -= bvec->bv_len + offset;
1358 iter->iov_offset = offset & ~PAGE_MASK;
1359 }
1360 }
1361
1362 return 0;
1363}
Linux 6.x block layer and io_uring tree(s)