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io_uring/rsrc: infer node from ctx on io_queue_rsrc_removal
[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}
169
9eae8655 170void io_rsrc_node_destroy(struct io_ring_ctx *ctx, struct io_rsrc_node *node)
73572984 171{
9eae8655
PB		 172 if (!io_alloc_cache_put(&ctx->rsrc_node_cache, &node->cache))
173 kfree(node);
73572984
JA		 174}
175
ef8ae64f
PB		 176void io_rsrc_node_ref_zero(struct io_rsrc_node *node)
177 __must_hold(&node->rsrc_data->ctx->uring_lock)
73572984 178{
73572984 179 struct io_ring_ctx *ctx = node->rsrc_data->ctx;
73572984 180
73572984
JA		 181 while (!list_empty(&ctx->rsrc_ref_list)) {
182 node = list_first_entry(&ctx->rsrc_ref_list,
183 struct io_rsrc_node, node);
184 /* recycle ref nodes in order */
c732ea24 185 if (node->refs)
73572984 186 break;
36b9818a
PB		 187 list_del(&node->node);
188 __io_rsrc_put_work(node);
d34b1b0b 189 }
0b222eeb
PB		 190 if (list_empty(&ctx->rsrc_ref_list) && unlikely(ctx->rsrc_quiesce))
191 wake_up_all(&ctx->rsrc_quiesce_wq);
73572984
JA		 192}
193
2933ae6e 194struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx)
73572984
JA		 195{
196 struct io_rsrc_node *ref_node;
9eae8655
PB		 197 struct io_cache_entry *entry;
198
199 entry = io_alloc_cache_get(&ctx->rsrc_node_cache);
200 if (entry) {
201 ref_node = container_of(entry, struct io_rsrc_node, cache);
202 } else {
203 ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
204 if (!ref_node)
205 return NULL;
206 }
73572984 207
13c22396 208 ref_node->rsrc_data = NULL;
ef8ae64f 209 ref_node->refs = 1;
73572984 210 INIT_LIST_HEAD(&ref_node->node);
c824986c 211 INIT_LIST_HEAD(&ref_node->item_list);
ff7c75ec 212 ref_node->inline_items = 0;
73572984
JA		 213 return ref_node;
214}
215
216void io_rsrc_node_switch(struct io_ring_ctx *ctx,
217 struct io_rsrc_data *data_to_kill)
218 __must_hold(&ctx->uring_lock)
219{
2933ae6e
PB		 220 struct io_rsrc_node *node = ctx->rsrc_node;
221 struct io_rsrc_node *backup = io_rsrc_node_alloc(ctx);
73572984 222
2933ae6e
PB		 223 if (WARN_ON_ONCE(!backup))
224 return;
73572984 225
2933ae6e
PB		 226 node->rsrc_data = data_to_kill;
227 list_add_tail(&node->node, &ctx->rsrc_ref_list);
228 /* put master ref */
229 io_put_rsrc_node(ctx, node);
230 ctx->rsrc_node = backup;
73572984
JA		 231}
232
2f2af35f 233int __io_rsrc_node_switch_start(struct io_ring_ctx *ctx)
73572984 234{
2f2af35f 235 struct io_rsrc_node *node = kzalloc(sizeof(*node), GFP_KERNEL);
528407b1 236
2f2af35f
PB		 237 if (!node)
238 return -ENOMEM;
239 io_alloc_cache_put(&ctx->rsrc_node_cache, &node->cache);
528407b1 240 return 0;
73572984
JA		 241}
242
243__cold static int io_rsrc_ref_quiesce(struct io_rsrc_data *data,
244 struct io_ring_ctx *ctx)
245{
4ea15b56 246 DEFINE_WAIT(we);
73572984
JA		 247 int ret;
248
249 /* As we may drop ->uring_lock, other task may have started quiesce */
250 if (data->quiesce)
251 return -ENXIO;
77e3202a
PB		 252 ret = io_rsrc_node_switch_start(ctx);
253 if (ret)
254 return ret;
255 io_rsrc_node_switch(ctx, data);
256
0b222eeb 257 if (list_empty(&ctx->rsrc_ref_list))
77e3202a 258 return 0;
73572984 259
7d481e03
PB		 260 if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) {
261 atomic_set(&ctx->cq_wait_nr, 1);
262 smp_mb();
263 }
264
0b222eeb 265 ctx->rsrc_quiesce++;
73572984
JA		 266 data->quiesce = true;
267 do {
4ea15b56 268 prepare_to_wait(&ctx->rsrc_quiesce_wq, &we, TASK_INTERRUPTIBLE);
eef81fca 269 mutex_unlock(&ctx->uring_lock);
4ea15b56 270
ef67fcb4 271 ret = io_run_task_work_sig(ctx);
77e3202a 272 if (ret < 0) {
77e3202a 273 mutex_lock(&ctx->uring_lock);
0b222eeb 274 if (list_empty(&ctx->rsrc_ref_list))
757ef468 275 ret = 0;
77e3202a
PB		 276 break;
277 }
4ea15b56
PB		 278
279 schedule();
280 __set_current_state(TASK_RUNNING);
eef81fca
PB		 281 mutex_lock(&ctx->uring_lock);
282 ret = 0;
0b222eeb 283 } while (!list_empty(&ctx->rsrc_ref_list));
73572984 284
4ea15b56
PB		 285 finish_wait(&ctx->rsrc_quiesce_wq, &we);
286 data->quiesce = false;
0b222eeb
PB		 287 ctx->rsrc_quiesce--;
288
7d481e03
PB		 289 if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) {
290 atomic_set(&ctx->cq_wait_nr, 0);
291 smp_mb();
292 }
73572984
JA		 293 return ret;
294}
295
296static void io_free_page_table(void **table, size_t size)
297{
298 unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
299
300 for (i = 0; i < nr_tables; i++)
301 kfree(table[i]);
302 kfree(table);
303}
304
305static void io_rsrc_data_free(struct io_rsrc_data *data)
306{
307 size_t size = data->nr * sizeof(data->tags[0][0]);
308
309 if (data->tags)
310 io_free_page_table((void **)data->tags, size);
311 kfree(data);
312}
313
314static __cold void **io_alloc_page_table(size_t size)
315{
316 unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
317 size_t init_size = size;
318 void **table;
319
320 table = kcalloc(nr_tables, sizeof(*table), GFP_KERNEL_ACCOUNT);
321 if (!table)
322 return NULL;
323
324 for (i = 0; i < nr_tables; i++) {
325 unsigned int this_size = min_t(size_t, size, PAGE_SIZE);
326
327 table[i] = kzalloc(this_size, GFP_KERNEL_ACCOUNT);
328 if (!table[i]) {
329 io_free_page_table(table, init_size);
330 return NULL;
331 }
332 size -= this_size;
333 }
334 return table;
335}
336
337__cold static int io_rsrc_data_alloc(struct io_ring_ctx *ctx,
338 rsrc_put_fn *do_put, u64 __user *utags,
339 unsigned nr, struct io_rsrc_data **pdata)
340{
341 struct io_rsrc_data *data;
6acd352d 342 int ret = 0;
73572984
JA		 343 unsigned i;
344
345 data = kzalloc(sizeof(*data), GFP_KERNEL);
346 if (!data)
347 return -ENOMEM;
348 data->tags = (u64 **)io_alloc_page_table(nr * sizeof(data->tags[0][0]));
349 if (!data->tags) {
350 kfree(data);
351 return -ENOMEM;
352 }
353
354 data->nr = nr;
355 data->ctx = ctx;
356 data->do_put = do_put;
357 if (utags) {
358 ret = -EFAULT;
359 for (i = 0; i < nr; i++) {
360 u64 *tag_slot = io_get_tag_slot(data, i);
361
362 if (copy_from_user(tag_slot, &utags[i],
363 sizeof(*tag_slot)))
364 goto fail;
365 }
366 }
73572984
JA		 367 *pdata = data;
368 return 0;
369fail:
370 io_rsrc_data_free(data);
371 return ret;
372}
373
374static int __io_sqe_files_update(struct io_ring_ctx *ctx,
375 struct io_uring_rsrc_update2 *up,
376 unsigned nr_args)
377{
378 u64 __user *tags = u64_to_user_ptr(up->tags);
379 __s32 __user *fds = u64_to_user_ptr(up->data);
380 struct io_rsrc_data *data = ctx->file_data;
381 struct io_fixed_file *file_slot;
382 struct file *file;
383 int fd, i, err = 0;
384 unsigned int done;
385 bool needs_switch = false;
386
387 if (!ctx->file_data)
388 return -ENXIO;
389 if (up->offset + nr_args > ctx->nr_user_files)
390 return -EINVAL;
391
392 for (done = 0; done < nr_args; done++) {
393 u64 tag = 0;
394
395 if ((tags && copy_from_user(&tag, &tags[done], sizeof(tag))) ||
396 copy_from_user(&fd, &fds[done], sizeof(fd))) {
397 err = -EFAULT;
398 break;
399 }
400 if ((fd == IORING_REGISTER_FILES_SKIP || fd == -1) && tag) {
401 err = -EINVAL;
402 break;
403 }
404 if (fd == IORING_REGISTER_FILES_SKIP)
405 continue;
406
407 i = array_index_nospec(up->offset + done, ctx->nr_user_files);
408 file_slot = io_fixed_file_slot(&ctx->file_table, i);
409
410 if (file_slot->file_ptr) {
411 file = (struct file *)(file_slot->file_ptr & FFS_MASK);
63fea890 412 err = io_queue_rsrc_removal(data, i, file);
73572984
JA		 413 if (err)
414 break;
415 file_slot->file_ptr = 0;
416 io_file_bitmap_clear(&ctx->file_table, i);
417 needs_switch = true;
418 }
419 if (fd != -1) {
420 file = fget(fd);
421 if (!file) {
422 err = -EBADF;
423 break;
424 }
425 /*
426 * Don't allow io_uring instances to be registered. If
427 * UNIX isn't enabled, then this causes a reference
428 * cycle and this instance can never get freed. If UNIX
429 * is enabled we'll handle it just fine, but there's
430 * still no point in allowing a ring fd as it doesn't
431 * support regular read/write anyway.
432 */
433 if (io_is_uring_fops(file)) {
434 fput(file);
435 err = -EBADF;
436 break;
437 }
438 err = io_scm_file_account(ctx, file);
439 if (err) {
440 fput(file);
441 break;
442 }
443 *io_get_tag_slot(data, i) = tag;
444 io_fixed_file_set(file_slot, file);
445 io_file_bitmap_set(&ctx->file_table, i);
446 }
447 }
448
449 if (needs_switch)
450 io_rsrc_node_switch(ctx, data);
451 return done ? done : err;
452}
453
454static int __io_sqe_buffers_update(struct io_ring_ctx *ctx,
455 struct io_uring_rsrc_update2 *up,
456 unsigned int nr_args)
457{
458 u64 __user *tags = u64_to_user_ptr(up->tags);
459 struct iovec iov, __user *iovs = u64_to_user_ptr(up->data);
460 struct page *last_hpage = NULL;
461 bool needs_switch = false;
462 __u32 done;
463 int i, err;
464
465 if (!ctx->buf_data)
466 return -ENXIO;
467 if (up->offset + nr_args > ctx->nr_user_bufs)
468 return -EINVAL;
469
470 for (done = 0; done < nr_args; done++) {
471 struct io_mapped_ubuf *imu;
73572984
JA		 472 u64 tag = 0;
473
474 err = io_copy_iov(ctx, &iov, iovs, done);
475 if (err)
476 break;
477 if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) {
478 err = -EFAULT;
479 break;
480 }
481 err = io_buffer_validate(&iov);
482 if (err)
483 break;
484 if (!iov.iov_base && tag) {
485 err = -EINVAL;
486 break;
487 }
488 err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage);
489 if (err)
490 break;
491
9a57fffe 492 i = array_index_nospec(up->offset + done, ctx->nr_user_bufs);
73572984
JA		 493 if (ctx->user_bufs[i] != ctx->dummy_ubuf) {
494 err = io_queue_rsrc_removal(ctx->buf_data, i,
63fea890 495 ctx->user_bufs[i]);
73572984
JA		 496 if (unlikely(err)) {
497 io_buffer_unmap(ctx, &imu);
498 break;
499 }
5ff4fdff 500 ctx->user_bufs[i] = ctx->dummy_ubuf;
73572984
JA		 501 needs_switch = true;
502 }
503
504 ctx->user_bufs[i] = imu;
953c37e0 505 *io_get_tag_slot(ctx->buf_data, i) = tag;
73572984
JA		 506 }
507
508 if (needs_switch)
509 io_rsrc_node_switch(ctx, ctx->buf_data);
510 return done ? done : err;
511}
512
513static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type,
514 struct io_uring_rsrc_update2 *up,
515 unsigned nr_args)
516{
517 __u32 tmp;
518 int err;
519
786788a8
PB		 520 lockdep_assert_held(&ctx->uring_lock);
521
73572984
JA		 522 if (check_add_overflow(up->offset, nr_args, &tmp))
523 return -EOVERFLOW;
524 err = io_rsrc_node_switch_start(ctx);
525 if (err)
526 return err;
527
528 switch (type) {
529 case IORING_RSRC_FILE:
530 return __io_sqe_files_update(ctx, up, nr_args);
531 case IORING_RSRC_BUFFER:
532 return __io_sqe_buffers_update(ctx, up, nr_args);
533 }
534 return -EINVAL;
535}
536
537int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
538 unsigned nr_args)
539{
540 struct io_uring_rsrc_update2 up;
541
542 if (!nr_args)
543 return -EINVAL;
544 memset(&up, 0, sizeof(up));
545 if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update)))
546 return -EFAULT;
547 if (up.resv || up.resv2)
548 return -EINVAL;
549 return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args);
550}
551
552int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
553 unsigned size, unsigned type)
554{
555 struct io_uring_rsrc_update2 up;
556
557 if (size != sizeof(up))
558 return -EINVAL;
559 if (copy_from_user(&up, arg, sizeof(up)))
560 return -EFAULT;
561 if (!up.nr || up.resv || up.resv2)
562 return -EINVAL;
563 return __io_register_rsrc_update(ctx, type, &up, up.nr);
564}
565
566__cold int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
567 unsigned int size, unsigned int type)
568{
569 struct io_uring_rsrc_register rr;
570
571 /* keep it extendible */
572 if (size != sizeof(rr))
573 return -EINVAL;
574
575 memset(&rr, 0, sizeof(rr));
576 if (copy_from_user(&rr, arg, size))
577 return -EFAULT;
578 if (!rr.nr || rr.resv2)
579 return -EINVAL;
580 if (rr.flags & ~IORING_RSRC_REGISTER_SPARSE)
581 return -EINVAL;
582
583 switch (type) {
584 case IORING_RSRC_FILE:
585 if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data)
586 break;
587 return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data),
588 rr.nr, u64_to_user_ptr(rr.tags));
589 case IORING_RSRC_BUFFER:
590 if (rr.flags & IORING_RSRC_REGISTER_SPARSE && rr.data)
591 break;
592 return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data),
593 rr.nr, u64_to_user_ptr(rr.tags));
594 }
595 return -EINVAL;
596}
597
d9808ceb 598int io_files_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
73572984 599{
f2ccb5ae 600 struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update);
73572984
JA		 601
602 if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
603 return -EINVAL;
604 if (sqe->rw_flags || sqe->splice_fd_in)
605 return -EINVAL;
606
607 up->offset = READ_ONCE(sqe->off);
608 up->nr_args = READ_ONCE(sqe->len);
609 if (!up->nr_args)
610 return -EINVAL;
611 up->arg = READ_ONCE(sqe->addr);
612 return 0;
613}
614
615static int io_files_update_with_index_alloc(struct io_kiocb *req,
616 unsigned int issue_flags)
617{
f2ccb5ae 618 struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update);
73572984
JA		 619 __s32 __user *fds = u64_to_user_ptr(up->arg);
620 unsigned int done;
621 struct file *file;
622 int ret, fd;
623
624 if (!req->ctx->file_data)
625 return -ENXIO;
626
627 for (done = 0; done < up->nr_args; done++) {
628 if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
629 ret = -EFAULT;
630 break;
631 }
632
633 file = fget(fd);
634 if (!file) {
635 ret = -EBADF;
636 break;
637 }
638 ret = io_fixed_fd_install(req, issue_flags, file,
639 IORING_FILE_INDEX_ALLOC);
640 if (ret < 0)
641 break;
642 if (copy_to_user(&fds[done], &ret, sizeof(ret))) {
f110ed84 643 __io_close_fixed(req->ctx, issue_flags, ret);
73572984
JA		 644 ret = -EFAULT;
645 break;
646 }
647 }
648
649 if (done)
650 return done;
651 return ret;
652}
653
d9808ceb 654int io_files_update(struct io_kiocb *req, unsigned int issue_flags)
73572984 655{
f2ccb5ae 656 struct io_rsrc_update *up = io_kiocb_to_cmd(req, struct io_rsrc_update);
73572984
JA		 657 struct io_ring_ctx *ctx = req->ctx;
658 struct io_uring_rsrc_update2 up2;
659 int ret;
660
661 up2.offset = up->offset;
662 up2.data = up->arg;
663 up2.nr = 0;
664 up2.tags = 0;
665 up2.resv = 0;
666 up2.resv2 = 0;
667
668 if (up->offset == IORING_FILE_INDEX_ALLOC) {
669 ret = io_files_update_with_index_alloc(req, issue_flags);
670 } else {
671 io_ring_submit_lock(ctx, issue_flags);
672 ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE,
673 &up2, up->nr_args);
674 io_ring_submit_unlock(ctx, issue_flags);
675 }
676
677 if (ret < 0)
678 req_set_fail(req);
679 io_req_set_res(req, ret, 0);
680 return IOU_OK;
681}
682
63fea890 683int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx, void *rsrc)
73572984 684{
63fea890
PB		 685 struct io_ring_ctx *ctx = data->ctx;
686 struct io_rsrc_node *node = ctx->rsrc_node;
73572984
JA		 687 u64 *tag_slot = io_get_tag_slot(data, idx);
688 struct io_rsrc_put *prsrc;
689
ff7c75ec
PB		 690 if (!node->inline_items) {
691 prsrc = &node->item;
692 node->inline_items++;
693 } else {
694 prsrc = kzalloc(sizeof(*prsrc), GFP_KERNEL);
695 if (!prsrc)
696 return -ENOMEM;
c899a5d7 697 list_add(&prsrc->list, &node->item_list);
ff7c75ec 698 }
73572984
JA		 699
700 prsrc->tag = *tag_slot;
701 *tag_slot = 0;
702 prsrc->rsrc = rsrc;
73572984
JA		 703 return 0;
704}
705
706void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
707{
73572984
JA		 708 int i;
709
710 for (i = 0; i < ctx->nr_user_files; i++) {
711 struct file *file = io_file_from_index(&ctx->file_table, i);
712
38eddb2c
PB		 713 /* skip scm accounted files, they'll be freed by ->ring_sock */
714 if (!file || io_file_need_scm(file))
73572984
JA		 715 continue;
716 io_file_bitmap_clear(&ctx->file_table, i);
717 fput(file);
718 }
73572984
JA		 719
720#if defined(CONFIG_UNIX)
721 if (ctx->ring_sock) {
722 struct sock *sock = ctx->ring_sock->sk;
723 struct sk_buff *skb;
724
725 while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
726 kfree_skb(skb);
727 }
728#endif
729 io_free_file_tables(&ctx->file_table);
02a4d923 730 io_file_table_set_alloc_range(ctx, 0, 0);
73572984
JA		 731 io_rsrc_data_free(ctx->file_data);
732 ctx->file_data = NULL;
733 ctx->nr_user_files = 0;
734}
735
736int io_sqe_files_unregister(struct io_ring_ctx *ctx)
737{
738 unsigned nr = ctx->nr_user_files;
739 int ret;
740
741 if (!ctx->file_data)
742 return -ENXIO;
743
744 /*
745 * Quiesce may unlock ->uring_lock, and while it's not held
746 * prevent new requests using the table.
747 */
748 ctx->nr_user_files = 0;
749 ret = io_rsrc_ref_quiesce(ctx->file_data, ctx);
750 ctx->nr_user_files = nr;
751 if (!ret)
752 __io_sqe_files_unregister(ctx);
753 return ret;
754}
755
756/*
757 * Ensure the UNIX gc is aware of our file set, so we are certain that
758 * the io_uring can be safely unregistered on process exit, even if we have
759 * loops in the file referencing. We account only files that can hold other
760 * files because otherwise they can't form a loop and so are not interesting
761 * for GC.
762 */
763int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
764{
765#if defined(CONFIG_UNIX)
766 struct sock *sk = ctx->ring_sock->sk;
767 struct sk_buff_head *head = &sk->sk_receive_queue;
768 struct scm_fp_list *fpl;
769 struct sk_buff *skb;
770
771 if (likely(!io_file_need_scm(file)))
772 return 0;
773
774 /*
775 * See if we can merge this file into an existing skb SCM_RIGHTS
776 * file set. If there's no room, fall back to allocating a new skb
777 * and filling it in.
778 */
779 spin_lock_irq(&head->lock);
780 skb = skb_peek(head);
781 if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)
782 __skb_unlink(skb, head);
783 else
784 skb = NULL;
785 spin_unlock_irq(&head->lock);
786
787 if (!skb) {
788 fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
789 if (!fpl)
790 return -ENOMEM;
791
792 skb = alloc_skb(0, GFP_KERNEL);
793 if (!skb) {
794 kfree(fpl);
795 return -ENOMEM;
796 }
797
798 fpl->user = get_uid(current_user());
799 fpl->max = SCM_MAX_FD;
800 fpl->count = 0;
801
802 UNIXCB(skb).fp = fpl;
803 skb->sk = sk;
0091bfc8 804 skb->scm_io_uring = 1;
73572984
JA		 805 skb->destructor = unix_destruct_scm;
806 refcount_add(skb->truesize, &sk->sk_wmem_alloc);
807 }
808
809 fpl = UNIXCB(skb).fp;
810 fpl->fp[fpl->count++] = get_file(file);
811 unix_inflight(fpl->user, file);
812 skb_queue_head(head, skb);
813 fput(file);
814#endif
815 return 0;
816}
817
d581076b 818static __cold void io_rsrc_file_scm_put(struct io_ring_ctx *ctx, struct file *file)
73572984 819{
73572984
JA		 820#if defined(CONFIG_UNIX)
821 struct sock *sock = ctx->ring_sock->sk;
822 struct sk_buff_head list, *head = &sock->sk_receive_queue;
823 struct sk_buff *skb;
824 int i;
825
73572984
JA		 826 __skb_queue_head_init(&list);
827
828 /*
829 * Find the skb that holds this file in its SCM_RIGHTS. When found,
830 * remove this entry and rearrange the file array.
831 */
832 skb = skb_dequeue(head);
833 while (skb) {
834 struct scm_fp_list *fp;
835
836 fp = UNIXCB(skb).fp;
837 for (i = 0; i < fp->count; i++) {
838 int left;
839
840 if (fp->fp[i] != file)
841 continue;
842
843 unix_notinflight(fp->user, fp->fp[i]);
844 left = fp->count - 1 - i;
845 if (left) {
846 memmove(&fp->fp[i], &fp->fp[i + 1],
847 left * sizeof(struct file *));
848 }
849 fp->count--;
850 if (!fp->count) {
851 kfree_skb(skb);
852 skb = NULL;
853 } else {
854 __skb_queue_tail(&list, skb);
855 }
856 fput(file);
857 file = NULL;
858 break;
859 }
860
861 if (!file)
862 break;
863
864 __skb_queue_tail(&list, skb);
865
866 skb = skb_dequeue(head);
867 }
868
869 if (skb_peek(&list)) {
870 spin_lock_irq(&head->lock);
871 while ((skb = __skb_dequeue(&list)) != NULL)
872 __skb_queue_tail(head, skb);
873 spin_unlock_irq(&head->lock);
874 }
73572984
JA		 875#endif
876}
877
d581076b
PB		 878static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
879{
880 struct file *file = prsrc->file;
881
882 if (likely(!io_file_need_scm(file)))
883 fput(file);
884 else
885 io_rsrc_file_scm_put(ctx, file);
886}
887
73572984
JA		 888int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
889 unsigned nr_args, u64 __user *tags)
890{
891 __s32 __user *fds = (__s32 __user *) arg;
892 struct file *file;
893 int fd, ret;
894 unsigned i;
895
896 if (ctx->file_data)
897 return -EBUSY;
898 if (!nr_args)
899 return -EINVAL;
900 if (nr_args > IORING_MAX_FIXED_FILES)
901 return -EMFILE;
902 if (nr_args > rlimit(RLIMIT_NOFILE))
903 return -EMFILE;
73572984
JA		 904 ret = io_rsrc_data_alloc(ctx, io_rsrc_file_put, tags, nr_args,
905 &ctx->file_data);
906 if (ret)
907 return ret;
908
909 if (!io_alloc_file_tables(&ctx->file_table, nr_args)) {
910 io_rsrc_data_free(ctx->file_data);
911 ctx->file_data = NULL;
912 return -ENOMEM;
913 }
914
915 for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
916 struct io_fixed_file *file_slot;
917
918 if (fds && copy_from_user(&fd, &fds[i], sizeof(fd))) {
919 ret = -EFAULT;
920 goto fail;
921 }
922 /* allow sparse sets */
923 if (!fds || fd == -1) {
924 ret = -EINVAL;
925 if (unlikely(*io_get_tag_slot(ctx->file_data, i)))
926 goto fail;
927 continue;
928 }
929
930 file = fget(fd);
931 ret = -EBADF;
932 if (unlikely(!file))
933 goto fail;
934
935 /*
936 * Don't allow io_uring instances to be registered. If UNIX
937 * isn't enabled, then this causes a reference cycle and this
938 * instance can never get freed. If UNIX is enabled we'll
939 * handle it just fine, but there's still no point in allowing
940 * a ring fd as it doesn't support regular read/write anyway.
941 */
942 if (io_is_uring_fops(file)) {
943 fput(file);
944 goto fail;
945 }
946 ret = io_scm_file_account(ctx, file);
947 if (ret) {
948 fput(file);
949 goto fail;
950 }
951 file_slot = io_fixed_file_slot(&ctx->file_table, i);
952 io_fixed_file_set(file_slot, file);
953 io_file_bitmap_set(&ctx->file_table, i);
954 }
955
6e73dffb
PB		 956 /* default it to the whole table */
957 io_file_table_set_alloc_range(ctx, 0, ctx->nr_user_files);
73572984
JA		 958 return 0;
959fail:
960 __io_sqe_files_unregister(ctx);
961 return ret;
962}
963
964static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
965{
966 io_buffer_unmap(ctx, &prsrc->buf);
967 prsrc->buf = NULL;
968}
969
970void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
971{
972 unsigned int i;
973
974 for (i = 0; i < ctx->nr_user_bufs; i++)
975 io_buffer_unmap(ctx, &ctx->user_bufs[i]);
976 kfree(ctx->user_bufs);
977 io_rsrc_data_free(ctx->buf_data);
978 ctx->user_bufs = NULL;
979 ctx->buf_data = NULL;
980 ctx->nr_user_bufs = 0;
981}
982
983int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
984{
985 unsigned nr = ctx->nr_user_bufs;
986 int ret;
987
988 if (!ctx->buf_data)
989 return -ENXIO;
990
991 /*
992 * Quiesce may unlock ->uring_lock, and while it's not held
993 * prevent new requests using the table.
994 */
995 ctx->nr_user_bufs = 0;
996 ret = io_rsrc_ref_quiesce(ctx->buf_data, ctx);
997 ctx->nr_user_bufs = nr;
998 if (!ret)
999 __io_sqe_buffers_unregister(ctx);
1000 return ret;
1001}
1002
1003/*
1004 * Not super efficient, but this is just a registration time. And we do cache
1005 * the last compound head, so generally we'll only do a full search if we don't
1006 * match that one.
1007 *
1008 * We check if the given compound head page has already been accounted, to
1009 * avoid double accounting it. This allows us to account the full size of the
1010 * page, not just the constituent pages of a huge page.
1011 */
1012static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
1013 int nr_pages, struct page *hpage)
1014{
1015 int i, j;
1016
1017 /* check current page array */
1018 for (i = 0; i < nr_pages; i++) {
1019 if (!PageCompound(pages[i]))
1020 continue;
1021 if (compound_head(pages[i]) == hpage)
1022 return true;
1023 }
1024
1025 /* check previously registered pages */
1026 for (i = 0; i < ctx->nr_user_bufs; i++) {
1027 struct io_mapped_ubuf *imu = ctx->user_bufs[i];
1028
1029 for (j = 0; j < imu->nr_bvecs; j++) {
1030 if (!PageCompound(imu->bvec[j].bv_page))
1031 continue;
1032 if (compound_head(imu->bvec[j].bv_page) == hpage)
1033 return true;
1034 }
1035 }
1036
1037 return false;
1038}
1039
1040static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
1041 int nr_pages, struct io_mapped_ubuf *imu,
1042 struct page **last_hpage)
1043{
1044 int i, ret;
1045
1046 imu->acct_pages = 0;
1047 for (i = 0; i < nr_pages; i++) {
1048 if (!PageCompound(pages[i])) {
1049 imu->acct_pages++;
1050 } else {
1051 struct page *hpage;
1052
1053 hpage = compound_head(pages[i]);
1054 if (hpage == *last_hpage)
1055 continue;
1056 *last_hpage = hpage;
1057 if (headpage_already_acct(ctx, pages, i, hpage))
1058 continue;
1059 imu->acct_pages += page_size(hpage) >> PAGE_SHIFT;
1060 }
1061 }
1062
1063 if (!imu->acct_pages)
1064 return 0;
1065
1066 ret = io_account_mem(ctx, imu->acct_pages);
1067 if (ret)
1068 imu->acct_pages = 0;
1069 return ret;
1070}
1071
1072struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages)
1073{
1074 unsigned long start, end, nr_pages;
1075 struct vm_area_struct **vmas = NULL;
1076 struct page **pages = NULL;
1077 int i, pret, ret = -ENOMEM;
1078
1079 end = (ubuf + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
1080 start = ubuf >> PAGE_SHIFT;
1081 nr_pages = end - start;
1082
1083 pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
1084 if (!pages)
1085 goto done;
1086
1087 vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *),
1088 GFP_KERNEL);
1089 if (!vmas)
1090 goto done;
1091
1092 ret = 0;
1093 mmap_read_lock(current->mm);
1094 pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
1095 pages, vmas);
1096 if (pret == nr_pages) {
edd47826
PB		 1097 struct file *file = vmas[0]->vm_file;
1098
73572984
JA		 1099 /* don't support file backed memory */
1100 for (i = 0; i < nr_pages; i++) {
edd47826
PB		 1101 if (vmas[i]->vm_file != file) {
1102 ret = -EINVAL;
1103 break;
1104 }
1105 if (!file)
73572984 1106 continue;
edd47826 1107 if (!vma_is_shmem(vmas[i]) && !is_file_hugepages(file)) {
73572984
JA		 1108 ret = -EOPNOTSUPP;
1109 break;
1110 }
1111 }
1112 *npages = nr_pages;
1113 } else {
1114 ret = pret < 0 ? pret : -EFAULT;
1115 }
1116 mmap_read_unlock(current->mm);
1117 if (ret) {
1118 /*
1119 * if we did partial map, or found file backed vmas,
1120 * release any pages we did get
1121 */
1122 if (pret > 0)
1123 unpin_user_pages(pages, pret);
1124 goto done;
1125 }
1126 ret = 0;
1127done:
1128 kvfree(vmas);
1129 if (ret < 0) {
1130 kvfree(pages);
1131 pages = ERR_PTR(ret);
1132 }
1133 return pages;
1134}
1135
1136static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
1137 struct io_mapped_ubuf **pimu,
1138 struct page **last_hpage)
1139{
1140 struct io_mapped_ubuf *imu = NULL;
1141 struct page **pages = NULL;
1142 unsigned long off;
1143 size_t size;
1144 int ret, nr_pages, i;
977bc873 1145 struct folio *folio = NULL;
73572984 1146
5ff4fdff
PB		 1147 *pimu = ctx->dummy_ubuf;
1148 if (!iov->iov_base)
73572984 1149 return 0;
73572984 1150
73572984 1151 ret = -ENOMEM;
73572984
JA		 1152 pages = io_pin_pages((unsigned long) iov->iov_base, iov->iov_len,
1153 &nr_pages);
1154 if (IS_ERR(pages)) {
1155 ret = PTR_ERR(pages);
1156 pages = NULL;
1157 goto done;
1158 }
1159
57bebf80
PB		 1160 /* If it's a huge page, try to coalesce them into a single bvec entry */
1161 if (nr_pages > 1) {
1162 folio = page_folio(pages[0]);
1163 for (i = 1; i < nr_pages; i++) {
1164 if (page_folio(pages[i]) != folio) {
1165 folio = NULL;
1166 break;
1167 }
1168 }
1169 if (folio) {
d2acf789
PB		 1170 /*
1171 * The pages are bound to the folio, it doesn't
1172 * actually unpin them but drops all but one reference,
1173 * which is usually put down by io_buffer_unmap().
1174 * Note, needs a better helper.
1175 */
1176 unpin_user_pages(&pages[1], nr_pages - 1);
57bebf80
PB		 1177 nr_pages = 1;
1178 }
1179 }
1180
73572984
JA		 1181 imu = kvmalloc(struct_size(imu, bvec, nr_pages), GFP_KERNEL);
1182 if (!imu)
1183 goto done;
1184
1185 ret = io_buffer_account_pin(ctx, pages, nr_pages, imu, last_hpage);
1186 if (ret) {
1187 unpin_user_pages(pages, nr_pages);
1188 goto done;
1189 }
1190
1191 off = (unsigned long) iov->iov_base & ~PAGE_MASK;
1192 size = iov->iov_len;
57bebf80
PB		 1193 /* store original address for later verification */
1194 imu->ubuf = (unsigned long) iov->iov_base;
1195 imu->ubuf_end = imu->ubuf + iov->iov_len;
1196 imu->nr_bvecs = nr_pages;
1197 *pimu = imu;
1198 ret = 0;
1199
1200 if (folio) {
1201 bvec_set_page(&imu->bvec[0], pages[0], size, off);
1202 goto done;
1203 }
73572984
JA		 1204 for (i = 0; i < nr_pages; i++) {
1205 size_t vec_len;
1206
1207 vec_len = min_t(size_t, size, PAGE_SIZE - off);
cc342a21 1208 bvec_set_page(&imu->bvec[i], pages[i], vec_len, off);
73572984
JA		 1209 off = 0;
1210 size -= vec_len;
1211 }
73572984
JA		 1212done:
1213 if (ret)
1214 kvfree(imu);
1215 kvfree(pages);
1216 return ret;
1217}
1218
1219static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args)
1220{
1221 ctx->user_bufs = kcalloc(nr_args, sizeof(*ctx->user_bufs), GFP_KERNEL);
1222 return ctx->user_bufs ? 0 : -ENOMEM;
1223}
1224
1225int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
1226 unsigned int nr_args, u64 __user *tags)
1227{
1228 struct page *last_hpage = NULL;
1229 struct io_rsrc_data *data;
1230 int i, ret;
1231 struct iovec iov;
1232
1233 BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16));
1234
1235 if (ctx->user_bufs)
1236 return -EBUSY;
1237 if (!nr_args || nr_args > IORING_MAX_REG_BUFFERS)
1238 return -EINVAL;
73572984
JA		 1239 ret = io_rsrc_data_alloc(ctx, io_rsrc_buf_put, tags, nr_args, &data);
1240 if (ret)
1241 return ret;
1242 ret = io_buffers_map_alloc(ctx, nr_args);
1243 if (ret) {
1244 io_rsrc_data_free(data);
1245 return ret;
1246 }
1247
1248 for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) {
1249 if (arg) {
1250 ret = io_copy_iov(ctx, &iov, arg, i);
1251 if (ret)
1252 break;
1253 ret = io_buffer_validate(&iov);
1254 if (ret)
1255 break;
1256 } else {
1257 memset(&iov, 0, sizeof(iov));
1258 }
1259
1260 if (!iov.iov_base && *io_get_tag_slot(data, i)) {
1261 ret = -EINVAL;
1262 break;
1263 }
1264
1265 ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i],
1266 &last_hpage);
1267 if (ret)
1268 break;
1269 }
1270
1271 WARN_ON_ONCE(ctx->buf_data);
1272
1273 ctx->buf_data = data;
1274 if (ret)
1275 __io_sqe_buffers_unregister(ctx);
73572984
JA		 1276 return ret;
1277}
c059f785
PB		 1278
1279int io_import_fixed(int ddir, struct iov_iter *iter,
1280 struct io_mapped_ubuf *imu,
1281 u64 buf_addr, size_t len)
1282{
1283 u64 buf_end;
1284 size_t offset;
1285
1286 if (WARN_ON_ONCE(!imu))
1287 return -EFAULT;
1288 if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end)))
1289 return -EFAULT;
1290 /* not inside the mapped region */
1291 if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end))
1292 return -EFAULT;
1293
1294 /*
6bf65a1b 1295 * Might not be a start of buffer, set size appropriately
c059f785
PB		 1296 * and advance us to the beginning.
1297 */
1298 offset = buf_addr - imu->ubuf;
1299 iov_iter_bvec(iter, ddir, imu->bvec, imu->nr_bvecs, offset + len);
1300
1301 if (offset) {
1302 /*
1303 * Don't use iov_iter_advance() here, as it's really slow for
1304 * using the latter parts of a big fixed buffer - it iterates
1305 * over each segment manually. We can cheat a bit here, because
1306 * we know that:
1307 *
1308 * 1) it's a BVEC iter, we set it up
1309 * 2) all bvecs are PAGE_SIZE in size, except potentially the
1310 * first and last bvec
1311 *
1312 * So just find our index, and adjust the iterator afterwards.
1313 * If the offset is within the first bvec (or the whole first
1314 * bvec, just use iov_iter_advance(). This makes it easier
1315 * since we can just skip the first segment, which may not
1316 * be PAGE_SIZE aligned.
1317 */
1318 const struct bio_vec *bvec = imu->bvec;
1319
1320 if (offset <= bvec->bv_len) {
57bebf80
PB		 1321 /*
1322 * Note, huge pages buffers consists of one large
1323 * bvec entry and should always go this way. The other
1324 * branch doesn't expect non PAGE_SIZE'd chunks.
1325 */
b000ae0e
PB		 1326 iter->bvec = bvec;
1327 iter->nr_segs = bvec->bv_len;
1328 iter->count -= offset;
1329 iter->iov_offset = offset;
c059f785
PB		 1330 } else {
1331 unsigned long seg_skip;
1332
1333 /* skip first vec */
1334 offset -= bvec->bv_len;
1335 seg_skip = 1 + (offset >> PAGE_SHIFT);
1336
1337 iter->bvec = bvec + seg_skip;
1338 iter->nr_segs -= seg_skip;
1339 iter->count -= bvec->bv_len + offset;
1340 iter->iov_offset = offset & ~PAGE_MASK;
1341 }
1342 }
1343
1344 return 0;
1345}
Linux 6.x block layer and io_uring tree(s)