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12#define pr_fmt(fmt) "%s: " fmt, __func__
13
14#include <linux/kernel.h>
15#include <linux/init.h>
16#include <linux/errno.h>
17#include <linux/time.h>
18#include <linux/aio_abi.h>
19#include <linux/export.h>
20#include <linux/syscalls.h>
21#include <linux/backing-dev.h>
22#include <linux/refcount.h>
23#include <linux/uio.h>
24
25#include <linux/sched/signal.h>
26#include <linux/fs.h>
27#include <linux/file.h>
28#include <linux/mm.h>
29#include <linux/mman.h>
30#include <linux/percpu.h>
31#include <linux/slab.h>
32#include <linux/timer.h>
33#include <linux/aio.h>
34#include <linux/highmem.h>
35#include <linux/workqueue.h>
36#include <linux/security.h>
37#include <linux/eventfd.h>
38#include <linux/blkdev.h>
39#include <linux/compat.h>
40#include <linux/migrate.h>
41#include <linux/ramfs.h>
42#include <linux/percpu-refcount.h>
43#include <linux/mount.h>
44#include <linux/pseudo_fs.h>
45
46#include <linux/uaccess.h>
47#include <linux/nospec.h>
48
49#include "internal.h"
50
51#define KIOCB_KEY 0
52
53#define AIO_RING_MAGIC 0xa10a10a1
54#define AIO_RING_COMPAT_FEATURES 1
55#define AIO_RING_INCOMPAT_FEATURES 0
56struct aio_ring {
57 unsigned id;
58 unsigned nr;
59 unsigned head;
60
61 unsigned tail;
62
63 unsigned magic;
64 unsigned compat_features;
65 unsigned incompat_features;
66 unsigned header_length;
67
68
69 struct io_event io_events[];
70};
71
72
73
74
75
76#define AIO_PLUG_THRESHOLD 2
77
78#define AIO_RING_PAGES 8
79
80struct kioctx_table {
81 struct rcu_head rcu;
82 unsigned nr;
83 struct kioctx __rcu *table[];
84};
85
86struct kioctx_cpu {
87 unsigned reqs_available;
88};
89
90struct ctx_rq_wait {
91 struct completion comp;
92 atomic_t count;
93};
94
95struct kioctx {
96 struct percpu_ref users;
97 atomic_t dead;
98
99 struct percpu_ref reqs;
100
101 unsigned long user_id;
102
103 struct __percpu kioctx_cpu *cpu;
104
105
106
107
108
109 unsigned req_batch;
110
111
112
113
114
115
116
117 unsigned max_reqs;
118
119
120 unsigned nr_events;
121
122 unsigned long mmap_base;
123 unsigned long mmap_size;
124
125 struct page **ring_pages;
126 long nr_pages;
127
128 struct rcu_work free_rwork;
129
130
131
132
133 struct ctx_rq_wait *rq_wait;
134
135 struct {
136
137
138
139
140
141
142
143
144 atomic_t reqs_available;
145 } ____cacheline_aligned_in_smp;
146
147 struct {
148 spinlock_t ctx_lock;
149 struct list_head active_reqs;
150 } ____cacheline_aligned_in_smp;
151
152 struct {
153 struct mutex ring_lock;
154 wait_queue_head_t wait;
155 } ____cacheline_aligned_in_smp;
156
157 struct {
158 unsigned tail;
159 unsigned completed_events;
160 spinlock_t completion_lock;
161 } ____cacheline_aligned_in_smp;
162
163 struct page *internal_pages[AIO_RING_PAGES];
164 struct file *aio_ring_file;
165
166 unsigned id;
167};
168
169
170
171
172
173struct fsync_iocb {
174 struct file *file;
175 struct work_struct work;
176 bool datasync;
177 struct cred *creds;
178};
179
180struct poll_iocb {
181 struct file *file;
182 struct wait_queue_head *head;
183 __poll_t events;
184 bool done;
185 bool cancelled;
186 struct wait_queue_entry wait;
187 struct work_struct work;
188};
189
190
191
192
193
194
195
196struct aio_kiocb {
197 union {
198 struct file *ki_filp;
199 struct kiocb rw;
200 struct fsync_iocb fsync;
201 struct poll_iocb poll;
202 };
203
204 struct kioctx *ki_ctx;
205 kiocb_cancel_fn *ki_cancel;
206
207 struct io_event ki_res;
208
209 struct list_head ki_list;
210
211 refcount_t ki_refcnt;
212
213
214
215
216
217 struct eventfd_ctx *ki_eventfd;
218};
219
220
221static DEFINE_SPINLOCK(aio_nr_lock);
222unsigned long aio_nr;
223unsigned long aio_max_nr = 0x10000;
224
225
226static struct kmem_cache *kiocb_cachep;
227static struct kmem_cache *kioctx_cachep;
228
229static struct vfsmount *aio_mnt;
230
231static const struct file_operations aio_ring_fops;
232static const struct address_space_operations aio_ctx_aops;
233
234static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
235{
236 struct file *file;
237 struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb);
238 if (IS_ERR(inode))
239 return ERR_CAST(inode);
240
241 inode->i_mapping->a_ops = &aio_ctx_aops;
242 inode->i_mapping->private_data = ctx;
243 inode->i_size = PAGE_SIZE * nr_pages;
244
245 file = alloc_file_pseudo(inode, aio_mnt, "[aio]",
246 O_RDWR, &aio_ring_fops);
247 if (IS_ERR(file))
248 iput(inode);
249 return file;
250}
251
252static int aio_init_fs_context(struct fs_context *fc)
253{
254 if (!init_pseudo(fc, AIO_RING_MAGIC))
255 return -ENOMEM;
256 fc->s_iflags |= SB_I_NOEXEC;
257 return 0;
258}
259
260
261
262
263
264static int __init aio_setup(void)
265{
266 static struct file_system_type aio_fs = {
267 .name = "aio",
268 .init_fs_context = aio_init_fs_context,
269 .kill_sb = kill_anon_super,
270 };
271 aio_mnt = kern_mount(&aio_fs);
272 if (IS_ERR(aio_mnt))
273 panic("Failed to create aio fs mount.");
274
275 kiocb_cachep = KMEM_CACHE(aio_kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
276 kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
277 return 0;
278}
279__initcall(aio_setup);
280
281static void put_aio_ring_file(struct kioctx *ctx)
282{
283 struct file *aio_ring_file = ctx->aio_ring_file;
284 struct address_space *i_mapping;
285
286 if (aio_ring_file) {
287 truncate_setsize(file_inode(aio_ring_file), 0);
288
289
290 i_mapping = aio_ring_file->f_mapping;
291 spin_lock(&i_mapping->private_lock);
292 i_mapping->private_data = NULL;
293 ctx->aio_ring_file = NULL;
294 spin_unlock(&i_mapping->private_lock);
295
296 fput(aio_ring_file);
297 }
298}
299
300static void aio_free_ring(struct kioctx *ctx)
301{
302 int i;
303
304
305
306
307 put_aio_ring_file(ctx);
308
309 for (i = 0; i < ctx->nr_pages; i++) {
310 struct page *page;
311 pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i,
312 page_count(ctx->ring_pages[i]));
313 page = ctx->ring_pages[i];
314 if (!page)
315 continue;
316 ctx->ring_pages[i] = NULL;
317 put_page(page);
318 }
319
320 if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages) {
321 kfree(ctx->ring_pages);
322 ctx->ring_pages = NULL;
323 }
324}
325
326static int aio_ring_mremap(struct vm_area_struct *vma)
327{
328 struct file *file = vma->vm_file;
329 struct mm_struct *mm = vma->vm_mm;
330 struct kioctx_table *table;
331 int i, res = -EINVAL;
332
333 spin_lock(&mm->ioctx_lock);
334 rcu_read_lock();
335 table = rcu_dereference(mm->ioctx_table);
336 for (i = 0; i < table->nr; i++) {
337 struct kioctx *ctx;
338
339 ctx = rcu_dereference(table->table[i]);
340 if (ctx && ctx->aio_ring_file == file) {
341 if (!atomic_read(&ctx->dead)) {
342 ctx->user_id = ctx->mmap_base = vma->vm_start;
343 res = 0;
344 }
345 break;
346 }
347 }
348
349 rcu_read_unlock();
350 spin_unlock(&mm->ioctx_lock);
351 return res;
352}
353
354static const struct vm_operations_struct aio_ring_vm_ops = {
355 .mremap = aio_ring_mremap,
356#if IS_ENABLED(CONFIG_MMU)
357 .fault = filemap_fault,
358 .map_pages = filemap_map_pages,
359 .page_mkwrite = filemap_page_mkwrite,
360#endif
361};
362
363static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
364{
365 vma->vm_flags |= VM_DONTEXPAND;
366 vma->vm_ops = &aio_ring_vm_ops;
367 return 0;
368}
369
370static const struct file_operations aio_ring_fops = {
371 .mmap = aio_ring_mmap,
372};
373
374#if IS_ENABLED(CONFIG_MIGRATION)
375static int aio_migratepage(struct address_space *mapping, struct page *new,
376 struct page *old, enum migrate_mode mode)
377{
378 struct kioctx *ctx;
379 unsigned long flags;
380 pgoff_t idx;
381 int rc;
382
383
384
385
386
387
388 if (mode == MIGRATE_SYNC_NO_COPY)
389 return -EINVAL;
390
391 rc = 0;
392
393
394 spin_lock(&mapping->private_lock);
395 ctx = mapping->private_data;
396 if (!ctx) {
397 rc = -EINVAL;
398 goto out;
399 }
400
401
402
403
404
405 if (!mutex_trylock(&ctx->ring_lock)) {
406 rc = -EAGAIN;
407 goto out;
408 }
409
410 idx = old->index;
411 if (idx < (pgoff_t)ctx->nr_pages) {
412
413 if (ctx->ring_pages[idx] != old)
414 rc = -EAGAIN;
415 } else
416 rc = -EINVAL;
417
418 if (rc != 0)
419 goto out_unlock;
420
421
422 BUG_ON(PageWriteback(old));
423 get_page(new);
424
425 rc = migrate_page_move_mapping(mapping, new, old, 1);
426 if (rc != MIGRATEPAGE_SUCCESS) {
427 put_page(new);
428 goto out_unlock;
429 }
430
431
432
433
434
435 spin_lock_irqsave(&ctx->completion_lock, flags);
436 migrate_page_copy(new, old);
437 BUG_ON(ctx->ring_pages[idx] != old);
438 ctx->ring_pages[idx] = new;
439 spin_unlock_irqrestore(&ctx->completion_lock, flags);
440
441
442 put_page(old);
443
444out_unlock:
445 mutex_unlock(&ctx->ring_lock);
446out:
447 spin_unlock(&mapping->private_lock);
448 return rc;
449}
450#endif
451
452static const struct address_space_operations aio_ctx_aops = {
453 .set_page_dirty = __set_page_dirty_no_writeback,
454#if IS_ENABLED(CONFIG_MIGRATION)
455 .migratepage = aio_migratepage,
456#endif
457};
458
459static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
460{
461 struct aio_ring *ring;
462 struct mm_struct *mm = current->mm;
463 unsigned long size, unused;
464 int nr_pages;
465 int i;
466 struct file *file;
467
468
469 nr_events += 2;
470
471 size = sizeof(struct aio_ring);
472 size += sizeof(struct io_event) * nr_events;
473
474 nr_pages = PFN_UP(size);
475 if (nr_pages < 0)
476 return -EINVAL;
477
478 file = aio_private_file(ctx, nr_pages);
479 if (IS_ERR(file)) {
480 ctx->aio_ring_file = NULL;
481 return -ENOMEM;
482 }
483
484 ctx->aio_ring_file = file;
485 nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring))
486 / sizeof(struct io_event);
487
488 ctx->ring_pages = ctx->internal_pages;
489 if (nr_pages > AIO_RING_PAGES) {
490 ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *),
491 GFP_KERNEL);
492 if (!ctx->ring_pages) {
493 put_aio_ring_file(ctx);
494 return -ENOMEM;
495 }
496 }
497
498 for (i = 0; i < nr_pages; i++) {
499 struct page *page;
500 page = find_or_create_page(file->f_mapping,
501 i, GFP_HIGHUSER | __GFP_ZERO);
502 if (!page)
503 break;
504 pr_debug("pid(%d) page[%d]->count=%d\n",
505 current->pid, i, page_count(page));
506 SetPageUptodate(page);
507 unlock_page(page);
508
509 ctx->ring_pages[i] = page;
510 }
511 ctx->nr_pages = i;
512
513 if (unlikely(i != nr_pages)) {
514 aio_free_ring(ctx);
515 return -ENOMEM;
516 }
517
518 ctx->mmap_size = nr_pages * PAGE_SIZE;
519 pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size);
520
521 if (mmap_write_lock_killable(mm)) {
522 ctx->mmap_size = 0;
523 aio_free_ring(ctx);
524 return -EINTR;
525 }
526
527 ctx->mmap_base = do_mmap(ctx->aio_ring_file, 0, ctx->mmap_size,
528 PROT_READ | PROT_WRITE,
529 MAP_SHARED, 0, &unused, NULL);
530 mmap_write_unlock(mm);
531 if (IS_ERR((void *)ctx->mmap_base)) {
532 ctx->mmap_size = 0;
533 aio_free_ring(ctx);
534 return -ENOMEM;
535 }
536
537 pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base);
538
539 ctx->user_id = ctx->mmap_base;
540 ctx->nr_events = nr_events;
541
542 ring = kmap_atomic(ctx->ring_pages[0]);
543 ring->nr = nr_events;
544 ring->id = ~0U;
545 ring->head = ring->tail = 0;
546 ring->magic = AIO_RING_MAGIC;
547 ring->compat_features = AIO_RING_COMPAT_FEATURES;
548 ring->incompat_features = AIO_RING_INCOMPAT_FEATURES;
549 ring->header_length = sizeof(struct aio_ring);
550 kunmap_atomic(ring);
551 flush_dcache_page(ctx->ring_pages[0]);
552
553 return 0;
554}
555
556#define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event))
557#define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event))
558#define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE)
559
560void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
561{
562 struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, rw);
563 struct kioctx *ctx = req->ki_ctx;
564 unsigned long flags;
565
566 if (WARN_ON_ONCE(!list_empty(&req->ki_list)))
567 return;
568
569 spin_lock_irqsave(&ctx->ctx_lock, flags);
570 list_add_tail(&req->ki_list, &ctx->active_reqs);
571 req->ki_cancel = cancel;
572 spin_unlock_irqrestore(&ctx->ctx_lock, flags);
573}
574EXPORT_SYMBOL(kiocb_set_cancel_fn);
575
576
577
578
579
580
581static void free_ioctx(struct work_struct *work)
582{
583 struct kioctx *ctx = container_of(to_rcu_work(work), struct kioctx,
584 free_rwork);
585 pr_debug("freeing %p\n", ctx);
586
587 aio_free_ring(ctx);
588 free_percpu(ctx->cpu);
589 percpu_ref_exit(&ctx->reqs);
590 percpu_ref_exit(&ctx->users);
591 kmem_cache_free(kioctx_cachep, ctx);
592}
593
594static void free_ioctx_reqs(struct percpu_ref *ref)
595{
596 struct kioctx *ctx = container_of(ref, struct kioctx, reqs);
597
598
599 if (ctx->rq_wait && atomic_dec_and_test(&ctx->rq_wait->count))
600 complete(&ctx->rq_wait->comp);
601
602
603 INIT_RCU_WORK(&ctx->free_rwork, free_ioctx);
604 queue_rcu_work(system_wq, &ctx->free_rwork);
605}
606
607
608
609
610
611
612static void free_ioctx_users(struct percpu_ref *ref)
613{
614 struct kioctx *ctx = container_of(ref, struct kioctx, users);
615 struct aio_kiocb *req;
616
617 spin_lock_irq(&ctx->ctx_lock);
618
619 while (!list_empty(&ctx->active_reqs)) {
620 req = list_first_entry(&ctx->active_reqs,
621 struct aio_kiocb, ki_list);
622 req->ki_cancel(&req->rw);
623 list_del_init(&req->ki_list);
624 }
625
626 spin_unlock_irq(&ctx->ctx_lock);
627
628 percpu_ref_kill(&ctx->reqs);
629 percpu_ref_put(&ctx->reqs);
630}
631
632static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
633{
634 unsigned i, new_nr;
635 struct kioctx_table *table, *old;
636 struct aio_ring *ring;
637
638 spin_lock(&mm->ioctx_lock);
639 table = rcu_dereference_raw(mm->ioctx_table);
640
641 while (1) {
642 if (table)
643 for (i = 0; i < table->nr; i++)
644 if (!rcu_access_pointer(table->table[i])) {
645 ctx->id = i;
646 rcu_assign_pointer(table->table[i], ctx);
647 spin_unlock(&mm->ioctx_lock);
648
649
650
651
652
653 ring = kmap_atomic(ctx->ring_pages[0]);
654 ring->id = ctx->id;
655 kunmap_atomic(ring);
656 return 0;
657 }
658
659 new_nr = (table ? table->nr : 1) * 4;
660 spin_unlock(&mm->ioctx_lock);
661
662 table = kzalloc(sizeof(*table) + sizeof(struct kioctx *) *
663 new_nr, GFP_KERNEL);
664 if (!table)
665 return -ENOMEM;
666
667 table->nr = new_nr;
668
669 spin_lock(&mm->ioctx_lock);
670 old = rcu_dereference_raw(mm->ioctx_table);
671
672 if (!old) {
673 rcu_assign_pointer(mm->ioctx_table, table);
674 } else if (table->nr > old->nr) {
675 memcpy(table->table, old->table,
676 old->nr * sizeof(struct kioctx *));
677
678 rcu_assign_pointer(mm->ioctx_table, table);
679 kfree_rcu(old, rcu);
680 } else {
681 kfree(table);
682 table = old;
683 }
684 }
685}
686
687static void aio_nr_sub(unsigned nr)
688{
689 spin_lock(&aio_nr_lock);
690 if (WARN_ON(aio_nr - nr > aio_nr))
691 aio_nr = 0;
692 else
693 aio_nr -= nr;
694 spin_unlock(&aio_nr_lock);
695}
696
697
698
699
700static struct kioctx *ioctx_alloc(unsigned nr_events)
701{
702 struct mm_struct *mm = current->mm;
703 struct kioctx *ctx;
704 int err = -ENOMEM;
705
706
707
708
709
710 unsigned int max_reqs = nr_events;
711
712
713
714
715
716
717
718
719
720
721 nr_events = max(nr_events, num_possible_cpus() * 4);
722 nr_events *= 2;
723
724
725 if (nr_events > (0x10000000U / sizeof(struct io_event))) {
726 pr_debug("ENOMEM: nr_events too high\n");
727 return ERR_PTR(-EINVAL);
728 }
729
730 if (!nr_events || (unsigned long)max_reqs > aio_max_nr)
731 return ERR_PTR(-EAGAIN);
732
733 ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL);
734 if (!ctx)
735 return ERR_PTR(-ENOMEM);
736
737 ctx->max_reqs = max_reqs;
738
739 spin_lock_init(&ctx->ctx_lock);
740 spin_lock_init(&ctx->completion_lock);
741 mutex_init(&ctx->ring_lock);
742
743
744 mutex_lock(&ctx->ring_lock);
745 init_waitqueue_head(&ctx->wait);
746
747 INIT_LIST_HEAD(&ctx->active_reqs);
748
749 if (percpu_ref_init(&ctx->users, free_ioctx_users, 0, GFP_KERNEL))
750 goto err;
751
752 if (percpu_ref_init(&ctx->reqs, free_ioctx_reqs, 0, GFP_KERNEL))
753 goto err;
754
755 ctx->cpu = alloc_percpu(struct kioctx_cpu);
756 if (!ctx->cpu)
757 goto err;
758
759 err = aio_setup_ring(ctx, nr_events);
760 if (err < 0)
761 goto err;
762
763 atomic_set(&ctx->reqs_available, ctx->nr_events - 1);
764 ctx->req_batch = (ctx->nr_events - 1) / (num_possible_cpus() * 4);
765 if (ctx->req_batch < 1)
766 ctx->req_batch = 1;
767
768
769 spin_lock(&aio_nr_lock);
770 if (aio_nr + ctx->max_reqs > aio_max_nr ||
771 aio_nr + ctx->max_reqs < aio_nr) {
772 spin_unlock(&aio_nr_lock);
773 err = -EAGAIN;
774 goto err_ctx;
775 }
776 aio_nr += ctx->max_reqs;
777 spin_unlock(&aio_nr_lock);
778
779 percpu_ref_get(&ctx->users);
780 percpu_ref_get(&ctx->reqs);
781
782 err = ioctx_add_table(ctx, mm);
783 if (err)
784 goto err_cleanup;
785
786
787 mutex_unlock(&ctx->ring_lock);
788
789 pr_debug("allocated ioctx %p[%ld]: mm=%p mask=0x%x\n",
790 ctx, ctx->user_id, mm, ctx->nr_events);
791 return ctx;
792
793err_cleanup:
794 aio_nr_sub(ctx->max_reqs);
795err_ctx:
796 atomic_set(&ctx->dead, 1);
797 if (ctx->mmap_size)
798 vm_munmap(ctx->mmap_base, ctx->mmap_size);
799 aio_free_ring(ctx);
800err:
801 mutex_unlock(&ctx->ring_lock);
802 free_percpu(ctx->cpu);
803 percpu_ref_exit(&ctx->reqs);
804 percpu_ref_exit(&ctx->users);
805 kmem_cache_free(kioctx_cachep, ctx);
806 pr_debug("error allocating ioctx %d\n", err);
807 return ERR_PTR(err);
808}
809
810
811
812
813
814
815static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
816 struct ctx_rq_wait *wait)
817{
818 struct kioctx_table *table;
819
820 spin_lock(&mm->ioctx_lock);
821 if (atomic_xchg(&ctx->dead, 1)) {
822 spin_unlock(&mm->ioctx_lock);
823 return -EINVAL;
824 }
825
826 table = rcu_dereference_raw(mm->ioctx_table);
827 WARN_ON(ctx != rcu_access_pointer(table->table[ctx->id]));
828 RCU_INIT_POINTER(table->table[ctx->id], NULL);
829 spin_unlock(&mm->ioctx_lock);
830
831
832 wake_up_all(&ctx->wait);
833
834
835
836
837
838
839
840
841 aio_nr_sub(ctx->max_reqs);
842
843 if (ctx->mmap_size)
844 vm_munmap(ctx->mmap_base, ctx->mmap_size);
845
846 ctx->rq_wait = wait;
847 percpu_ref_kill(&ctx->users);
848 return 0;
849}
850
851
852
853
854
855
856
857
858
859void exit_aio(struct mm_struct *mm)
860{
861 struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table);
862 struct ctx_rq_wait wait;
863 int i, skipped;
864
865 if (!table)
866 return;
867
868 atomic_set(&wait.count, table->nr);
869 init_completion(&wait.comp);
870
871 skipped = 0;
872 for (i = 0; i < table->nr; ++i) {
873 struct kioctx *ctx =
874 rcu_dereference_protected(table->table[i], true);
875
876 if (!ctx) {
877 skipped++;
878 continue;
879 }
880
881
882
883
884
885
886
887
888 ctx->mmap_size = 0;
889 kill_ioctx(mm, ctx, &wait);
890 }
891
892 if (!atomic_sub_and_test(skipped, &wait.count)) {
893
894 wait_for_completion(&wait.comp);
895 }
896
897 RCU_INIT_POINTER(mm->ioctx_table, NULL);
898 kfree(table);
899}
900
901static void put_reqs_available(struct kioctx *ctx, unsigned nr)
902{
903 struct kioctx_cpu *kcpu;
904 unsigned long flags;
905
906 local_irq_save(flags);
907 kcpu = this_cpu_ptr(ctx->cpu);
908 kcpu->reqs_available += nr;
909
910 while (kcpu->reqs_available >= ctx->req_batch * 2) {
911 kcpu->reqs_available -= ctx->req_batch;
912 atomic_add(ctx->req_batch, &ctx->reqs_available);
913 }
914
915 local_irq_restore(flags);
916}
917
918static bool __get_reqs_available(struct kioctx *ctx)
919{
920 struct kioctx_cpu *kcpu;
921 bool ret = false;
922 unsigned long flags;
923
924 local_irq_save(flags);
925 kcpu = this_cpu_ptr(ctx->cpu);
926 if (!kcpu->reqs_available) {
927 int old, avail = atomic_read(&ctx->reqs_available);
928
929 do {
930 if (avail < ctx->req_batch)
931 goto out;
932
933 old = avail;
934 avail = atomic_cmpxchg(&ctx->reqs_available,
935 avail, avail - ctx->req_batch);
936 } while (avail != old);
937
938 kcpu->reqs_available += ctx->req_batch;
939 }
940
941 ret = true;
942 kcpu->reqs_available--;
943out:
944 local_irq_restore(flags);
945 return ret;
946}
947
948
949
950
951
952
953
954
955static void refill_reqs_available(struct kioctx *ctx, unsigned head,
956 unsigned tail)
957{
958 unsigned events_in_ring, completed;
959
960
961 head %= ctx->nr_events;
962 if (head <= tail)
963 events_in_ring = tail - head;
964 else
965 events_in_ring = ctx->nr_events - (head - tail);
966
967 completed = ctx->completed_events;
968 if (events_in_ring < completed)
969 completed -= events_in_ring;
970 else
971 completed = 0;
972
973 if (!completed)
974 return;
975
976 ctx->completed_events -= completed;
977 put_reqs_available(ctx, completed);
978}
979
980
981
982
983
984static void user_refill_reqs_available(struct kioctx *ctx)
985{
986 spin_lock_irq(&ctx->completion_lock);
987 if (ctx->completed_events) {
988 struct aio_ring *ring;
989 unsigned head;
990
991
992
993
994
995
996
997
998
999
1000 ring = kmap_atomic(ctx->ring_pages[0]);
1001 head = ring->head;
1002 kunmap_atomic(ring);
1003
1004 refill_reqs_available(ctx, head, ctx->tail);
1005 }
1006
1007 spin_unlock_irq(&ctx->completion_lock);
1008}
1009
1010static bool get_reqs_available(struct kioctx *ctx)
1011{
1012 if (__get_reqs_available(ctx))
1013 return true;
1014 user_refill_reqs_available(ctx);
1015 return __get_reqs_available(ctx);
1016}
1017
1018
1019
1020
1021
1022
1023
1024
1025static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
1026{
1027 struct aio_kiocb *req;
1028
1029 req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL);
1030 if (unlikely(!req))
1031 return NULL;
1032
1033 if (unlikely(!get_reqs_available(ctx))) {
1034 kmem_cache_free(kiocb_cachep, req);
1035 return NULL;
1036 }
1037
1038 percpu_ref_get(&ctx->reqs);
1039 req->ki_ctx = ctx;
1040 INIT_LIST_HEAD(&req->ki_list);
1041 refcount_set(&req->ki_refcnt, 2);
1042 req->ki_eventfd = NULL;
1043 return req;
1044}
1045
1046static struct kioctx *lookup_ioctx(unsigned long ctx_id)
1047{
1048 struct aio_ring __user *ring = (void __user *)ctx_id;
1049 struct mm_struct *mm = current->mm;
1050 struct kioctx *ctx, *ret = NULL;
1051 struct kioctx_table *table;
1052 unsigned id;
1053
1054 if (get_user(id, &ring->id))
1055 return NULL;
1056
1057 rcu_read_lock();
1058 table = rcu_dereference(mm->ioctx_table);
1059
1060 if (!table || id >= table->nr)
1061 goto out;
1062
1063 id = array_index_nospec(id, table->nr);
1064 ctx = rcu_dereference(table->table[id]);
1065 if (ctx && ctx->user_id == ctx_id) {
1066 if (percpu_ref_tryget_live(&ctx->users))
1067 ret = ctx;
1068 }
1069out:
1070 rcu_read_unlock();
1071 return ret;
1072}
1073
1074static inline void iocb_destroy(struct aio_kiocb *iocb)
1075{
1076 if (iocb->ki_eventfd)
1077 eventfd_ctx_put(iocb->ki_eventfd);
1078 if (iocb->ki_filp)
1079 fput(iocb->ki_filp);
1080 percpu_ref_put(&iocb->ki_ctx->reqs);
1081 kmem_cache_free(kiocb_cachep, iocb);
1082}
1083
1084
1085
1086
1087static void aio_complete(struct aio_kiocb *iocb)
1088{
1089 struct kioctx *ctx = iocb->ki_ctx;
1090 struct aio_ring *ring;
1091 struct io_event *ev_page, *event;
1092 unsigned tail, pos, head;
1093 unsigned long flags;
1094
1095
1096
1097
1098
1099
1100 spin_lock_irqsave(&ctx->completion_lock, flags);
1101
1102 tail = ctx->tail;
1103 pos = tail + AIO_EVENTS_OFFSET;
1104
1105 if (++tail >= ctx->nr_events)
1106 tail = 0;
1107
1108 ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
1109 event = ev_page + pos % AIO_EVENTS_PER_PAGE;
1110
1111 *event = iocb->ki_res;
1112
1113 kunmap_atomic(ev_page);
1114 flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
1115
1116 pr_debug("%p[%u]: %p: %p %Lx %Lx %Lx\n", ctx, tail, iocb,
1117 (void __user *)(unsigned long)iocb->ki_res.obj,
1118 iocb->ki_res.data, iocb->ki_res.res, iocb->ki_res.res2);
1119
1120
1121
1122
1123 smp_wmb();
1124
1125 ctx->tail = tail;
1126
1127 ring = kmap_atomic(ctx->ring_pages[0]);
1128 head = ring->head;
1129 ring->tail = tail;
1130 kunmap_atomic(ring);
1131 flush_dcache_page(ctx->ring_pages[0]);
1132
1133 ctx->completed_events++;
1134 if (ctx->completed_events > 1)
1135 refill_reqs_available(ctx, head, tail);
1136 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1137
1138 pr_debug("added to ring %p at [%u]\n", iocb, tail);
1139
1140
1141
1142
1143
1144
1145 if (iocb->ki_eventfd)
1146 eventfd_signal(iocb->ki_eventfd, 1);
1147
1148
1149
1150
1151
1152
1153
1154 smp_mb();
1155
1156 if (waitqueue_active(&ctx->wait))
1157 wake_up(&ctx->wait);
1158}
1159
1160static inline void iocb_put(struct aio_kiocb *iocb)
1161{
1162 if (refcount_dec_and_test(&iocb->ki_refcnt)) {
1163 aio_complete(iocb);
1164 iocb_destroy(iocb);
1165 }
1166}
1167
1168
1169
1170
1171
1172static long aio_read_events_ring(struct kioctx *ctx,
1173 struct io_event __user *event, long nr)
1174{
1175 struct aio_ring *ring;
1176 unsigned head, tail, pos;
1177 long ret = 0;
1178 int copy_ret;
1179
1180
1181
1182
1183
1184
1185
1186 sched_annotate_sleep();
1187 mutex_lock(&ctx->ring_lock);
1188
1189
1190 ring = kmap_atomic(ctx->ring_pages[0]);
1191 head = ring->head;
1192 tail = ring->tail;
1193 kunmap_atomic(ring);
1194
1195
1196
1197
1198
1199 smp_rmb();
1200
1201 pr_debug("h%u t%u m%u\n", head, tail, ctx->nr_events);
1202
1203 if (head == tail)
1204 goto out;
1205
1206 head %= ctx->nr_events;
1207 tail %= ctx->nr_events;
1208
1209 while (ret < nr) {
1210 long avail;
1211 struct io_event *ev;
1212 struct page *page;
1213
1214 avail = (head <= tail ? tail : ctx->nr_events) - head;
1215 if (head == tail)
1216 break;
1217
1218 pos = head + AIO_EVENTS_OFFSET;
1219 page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE];
1220 pos %= AIO_EVENTS_PER_PAGE;
1221
1222 avail = min(avail, nr - ret);
1223 avail = min_t(long, avail, AIO_EVENTS_PER_PAGE - pos);
1224
1225 ev = kmap(page);
1226 copy_ret = copy_to_user(event + ret, ev + pos,
1227 sizeof(*ev) * avail);
1228 kunmap(page);
1229
1230 if (unlikely(copy_ret)) {
1231 ret = -EFAULT;
1232 goto out;
1233 }
1234
1235 ret += avail;
1236 head += avail;
1237 head %= ctx->nr_events;
1238 }
1239
1240 ring = kmap_atomic(ctx->ring_pages[0]);
1241 ring->head = head;
1242 kunmap_atomic(ring);
1243 flush_dcache_page(ctx->ring_pages[0]);
1244
1245 pr_debug("%li h%u t%u\n", ret, head, tail);
1246out:
1247 mutex_unlock(&ctx->ring_lock);
1248
1249 return ret;
1250}
1251
1252static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr,
1253 struct io_event __user *event, long *i)
1254{
1255 long ret = aio_read_events_ring(ctx, event + *i, nr - *i);
1256
1257 if (ret > 0)
1258 *i += ret;
1259
1260 if (unlikely(atomic_read(&ctx->dead)))
1261 ret = -EINVAL;
1262
1263 if (!*i)
1264 *i = ret;
1265
1266 return ret < 0 || *i >= min_nr;
1267}
1268
1269static long read_events(struct kioctx *ctx, long min_nr, long nr,
1270 struct io_event __user *event,
1271 ktime_t until)
1272{
1273 long ret = 0;
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289 if (until == 0)
1290 aio_read_events(ctx, min_nr, nr, event, &ret);
1291 else
1292 wait_event_interruptible_hrtimeout(ctx->wait,
1293 aio_read_events(ctx, min_nr, nr, event, &ret),
1294 until);
1295 return ret;
1296}
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
1312{
1313 struct kioctx *ioctx = NULL;
1314 unsigned long ctx;
1315 long ret;
1316
1317 ret = get_user(ctx, ctxp);
1318 if (unlikely(ret))
1319 goto out;
1320
1321 ret = -EINVAL;
1322 if (unlikely(ctx || nr_events == 0)) {
1323 pr_debug("EINVAL: ctx %lu nr_events %u\n",
1324 ctx, nr_events);
1325 goto out;
1326 }
1327
1328 ioctx = ioctx_alloc(nr_events);
1329 ret = PTR_ERR(ioctx);
1330 if (!IS_ERR(ioctx)) {
1331 ret = put_user(ioctx->user_id, ctxp);
1332 if (ret)
1333 kill_ioctx(current->mm, ioctx, NULL);
1334 percpu_ref_put(&ioctx->users);
1335 }
1336
1337out:
1338 return ret;
1339}
1340
1341#ifdef CONFIG_COMPAT
1342COMPAT_SYSCALL_DEFINE2(io_setup, unsigned, nr_events, u32 __user *, ctx32p)
1343{
1344 struct kioctx *ioctx = NULL;
1345 unsigned long ctx;
1346 long ret;
1347
1348 ret = get_user(ctx, ctx32p);
1349 if (unlikely(ret))
1350 goto out;
1351
1352 ret = -EINVAL;
1353 if (unlikely(ctx || nr_events == 0)) {
1354 pr_debug("EINVAL: ctx %lu nr_events %u\n",
1355 ctx, nr_events);
1356 goto out;
1357 }
1358
1359 ioctx = ioctx_alloc(nr_events);
1360 ret = PTR_ERR(ioctx);
1361 if (!IS_ERR(ioctx)) {
1362
1363 ret = put_user((u32)ioctx->user_id, ctx32p);
1364 if (ret)
1365 kill_ioctx(current->mm, ioctx, NULL);
1366 percpu_ref_put(&ioctx->users);
1367 }
1368
1369out:
1370 return ret;
1371}
1372#endif
1373
1374
1375
1376
1377
1378
1379
1380SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
1381{
1382 struct kioctx *ioctx = lookup_ioctx(ctx);
1383 if (likely(NULL != ioctx)) {
1384 struct ctx_rq_wait wait;
1385 int ret;
1386
1387 init_completion(&wait.comp);
1388 atomic_set(&wait.count, 1);
1389
1390
1391
1392
1393
1394 ret = kill_ioctx(current->mm, ioctx, &wait);
1395 percpu_ref_put(&ioctx->users);
1396
1397
1398
1399
1400
1401 if (!ret)
1402 wait_for_completion(&wait.comp);
1403
1404 return ret;
1405 }
1406 pr_debug("EINVAL: invalid context id\n");
1407 return -EINVAL;
1408}
1409
1410static void aio_remove_iocb(struct aio_kiocb *iocb)
1411{
1412 struct kioctx *ctx = iocb->ki_ctx;
1413 unsigned long flags;
1414
1415 spin_lock_irqsave(&ctx->ctx_lock, flags);
1416 list_del(&iocb->ki_list);
1417 spin_unlock_irqrestore(&ctx->ctx_lock, flags);
1418}
1419
1420static void aio_complete_rw(struct kiocb *kiocb, long res, long res2)
1421{
1422 struct aio_kiocb *iocb = container_of(kiocb, struct aio_kiocb, rw);
1423
1424 if (!list_empty_careful(&iocb->ki_list))
1425 aio_remove_iocb(iocb);
1426
1427 if (kiocb->ki_flags & IOCB_WRITE) {
1428 struct inode *inode = file_inode(kiocb->ki_filp);
1429
1430
1431
1432
1433
1434 if (S_ISREG(inode->i_mode))
1435 __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
1436 file_end_write(kiocb->ki_filp);
1437 }
1438
1439 iocb->ki_res.res = res;
1440 iocb->ki_res.res2 = res2;
1441 iocb_put(iocb);
1442}
1443
1444static int aio_prep_rw(struct kiocb *req, const struct iocb *iocb)
1445{
1446 int ret;
1447
1448 req->ki_complete = aio_complete_rw;
1449 req->private = NULL;
1450 req->ki_pos = iocb->aio_offset;
1451 req->ki_flags = iocb_flags(req->ki_filp);
1452 if (iocb->aio_flags & IOCB_FLAG_RESFD)
1453 req->ki_flags |= IOCB_EVENTFD;
1454 req->ki_hint = ki_hint_validate(file_write_hint(req->ki_filp));
1455 if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {
1456
1457
1458
1459
1460
1461 ret = ioprio_check_cap(iocb->aio_reqprio);
1462 if (ret) {
1463 pr_debug("aio ioprio check cap error: %d\n", ret);
1464 return ret;
1465 }
1466
1467 req->ki_ioprio = iocb->aio_reqprio;
1468 } else
1469 req->ki_ioprio = get_current_ioprio();
1470
1471 ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags);
1472 if (unlikely(ret))
1473 return ret;
1474
1475 req->ki_flags &= ~IOCB_HIPRI;
1476 return 0;
1477}
1478
1479static ssize_t aio_setup_rw(int rw, const struct iocb *iocb,
1480 struct iovec **iovec, bool vectored, bool compat,
1481 struct iov_iter *iter)
1482{
1483 void __user *buf = (void __user *)(uintptr_t)iocb->aio_buf;
1484 size_t len = iocb->aio_nbytes;
1485
1486 if (!vectored) {
1487 ssize_t ret = import_single_range(rw, buf, len, *iovec, iter);
1488 *iovec = NULL;
1489 return ret;
1490 }
1491
1492 return __import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter, compat);
1493}
1494
1495static inline void aio_rw_done(struct kiocb *req, ssize_t ret)
1496{
1497 switch (ret) {
1498 case -EIOCBQUEUED:
1499 break;
1500 case -ERESTARTSYS:
1501 case -ERESTARTNOINTR:
1502 case -ERESTARTNOHAND:
1503 case -ERESTART_RESTARTBLOCK:
1504
1505
1506
1507
1508 ret = -EINTR;
1509 fallthrough;
1510 default:
1511 req->ki_complete(req, ret, 0);
1512 }
1513}
1514
1515static int aio_read(struct kiocb *req, const struct iocb *iocb,
1516 bool vectored, bool compat)
1517{
1518 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
1519 struct iov_iter iter;
1520 struct file *file;
1521 int ret;
1522
1523 ret = aio_prep_rw(req, iocb);
1524 if (ret)
1525 return ret;
1526 file = req->ki_filp;
1527 if (unlikely(!(file->f_mode & FMODE_READ)))
1528 return -EBADF;
1529 ret = -EINVAL;
1530 if (unlikely(!file->f_op->read_iter))
1531 return -EINVAL;
1532
1533 ret = aio_setup_rw(READ, iocb, &iovec, vectored, compat, &iter);
1534 if (ret < 0)
1535 return ret;
1536 ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter));
1537 if (!ret)
1538 aio_rw_done(req, call_read_iter(file, req, &iter));
1539 kfree(iovec);
1540 return ret;
1541}
1542
1543static int aio_write(struct kiocb *req, const struct iocb *iocb,
1544 bool vectored, bool compat)
1545{
1546 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
1547 struct iov_iter iter;
1548 struct file *file;
1549 int ret;
1550
1551 ret = aio_prep_rw(req, iocb);
1552 if (ret)
1553 return ret;
1554 file = req->ki_filp;
1555
1556 if (unlikely(!(file->f_mode & FMODE_WRITE)))
1557 return -EBADF;
1558 if (unlikely(!file->f_op->write_iter))
1559 return -EINVAL;
1560
1561 ret = aio_setup_rw(WRITE, iocb, &iovec, vectored, compat, &iter);
1562 if (ret < 0)
1563 return ret;
1564 ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter));
1565 if (!ret) {
1566
1567
1568
1569
1570
1571
1572
1573 if (S_ISREG(file_inode(file)->i_mode)) {
1574 sb_start_write(file_inode(file)->i_sb);
1575 __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE);
1576 }
1577 req->ki_flags |= IOCB_WRITE;
1578 aio_rw_done(req, call_write_iter(file, req, &iter));
1579 }
1580 kfree(iovec);
1581 return ret;
1582}
1583
1584static void aio_fsync_work(struct work_struct *work)
1585{
1586 struct aio_kiocb *iocb = container_of(work, struct aio_kiocb, fsync.work);
1587 const struct cred *old_cred = override_creds(iocb->fsync.creds);
1588
1589 iocb->ki_res.res = vfs_fsync(iocb->fsync.file, iocb->fsync.datasync);
1590 revert_creds(old_cred);
1591 put_cred(iocb->fsync.creds);
1592 iocb_put(iocb);
1593}
1594
1595static int aio_fsync(struct fsync_iocb *req, const struct iocb *iocb,
1596 bool datasync)
1597{
1598 if (unlikely(iocb->aio_buf || iocb->aio_offset || iocb->aio_nbytes ||
1599 iocb->aio_rw_flags))
1600 return -EINVAL;
1601
1602 if (unlikely(!req->file->f_op->fsync))
1603 return -EINVAL;
1604
1605 req->creds = prepare_creds();
1606 if (!req->creds)
1607 return -ENOMEM;
1608
1609 req->datasync = datasync;
1610 INIT_WORK(&req->work, aio_fsync_work);
1611 schedule_work(&req->work);
1612 return 0;
1613}
1614
1615static void aio_poll_put_work(struct work_struct *work)
1616{
1617 struct poll_iocb *req = container_of(work, struct poll_iocb, work);
1618 struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll);
1619
1620 iocb_put(iocb);
1621}
1622
1623static void aio_poll_complete_work(struct work_struct *work)
1624{
1625 struct poll_iocb *req = container_of(work, struct poll_iocb, work);
1626 struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll);
1627 struct poll_table_struct pt = { ._key = req->events };
1628 struct kioctx *ctx = iocb->ki_ctx;
1629 __poll_t mask = 0;
1630
1631 if (!READ_ONCE(req->cancelled))
1632 mask = vfs_poll(req->file, &pt) & req->events;
1633
1634
1635
1636
1637
1638
1639
1640
1641 spin_lock_irq(&ctx->ctx_lock);
1642 if (!mask && !READ_ONCE(req->cancelled)) {
1643 add_wait_queue(req->head, &req->wait);
1644 spin_unlock_irq(&ctx->ctx_lock);
1645 return;
1646 }
1647 list_del_init(&iocb->ki_list);
1648 iocb->ki_res.res = mangle_poll(mask);
1649 req->done = true;
1650 spin_unlock_irq(&ctx->ctx_lock);
1651
1652 iocb_put(iocb);
1653}
1654
1655
1656static int aio_poll_cancel(struct kiocb *iocb)
1657{
1658 struct aio_kiocb *aiocb = container_of(iocb, struct aio_kiocb, rw);
1659 struct poll_iocb *req = &aiocb->poll;
1660
1661 spin_lock(&req->head->lock);
1662 WRITE_ONCE(req->cancelled, true);
1663 if (!list_empty(&req->wait.entry)) {
1664 list_del_init(&req->wait.entry);
1665 schedule_work(&aiocb->poll.work);
1666 }
1667 spin_unlock(&req->head->lock);
1668
1669 return 0;
1670}
1671
1672static int aio_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
1673 void *key)
1674{
1675 struct poll_iocb *req = container_of(wait, struct poll_iocb, wait);
1676 struct aio_kiocb *iocb = container_of(req, struct aio_kiocb, poll);
1677 __poll_t mask = key_to_poll(key);
1678 unsigned long flags;
1679
1680
1681 if (mask && !(mask & req->events))
1682 return 0;
1683
1684 list_del_init(&req->wait.entry);
1685
1686 if (mask && spin_trylock_irqsave(&iocb->ki_ctx->ctx_lock, flags)) {
1687 struct kioctx *ctx = iocb->ki_ctx;
1688
1689
1690
1691
1692
1693
1694
1695 list_del(&iocb->ki_list);
1696 iocb->ki_res.res = mangle_poll(mask);
1697 req->done = true;
1698 if (iocb->ki_eventfd && eventfd_signal_allowed()) {
1699 iocb = NULL;
1700 INIT_WORK(&req->work, aio_poll_put_work);
1701 schedule_work(&req->work);
1702 }
1703 spin_unlock_irqrestore(&ctx->ctx_lock, flags);
1704 if (iocb)
1705 iocb_put(iocb);
1706 } else {
1707 schedule_work(&req->work);
1708 }
1709 return 1;
1710}
1711
1712struct aio_poll_table {
1713 struct poll_table_struct pt;
1714 struct aio_kiocb *iocb;
1715 int error;
1716};
1717
1718static void
1719aio_poll_queue_proc(struct file *file, struct wait_queue_head *head,
1720 struct poll_table_struct *p)
1721{
1722 struct aio_poll_table *pt = container_of(p, struct aio_poll_table, pt);
1723
1724
1725 if (unlikely(pt->iocb->poll.head)) {
1726 pt->error = -EINVAL;
1727 return;
1728 }
1729
1730 pt->error = 0;
1731 pt->iocb->poll.head = head;
1732 add_wait_queue(head, &pt->iocb->poll.wait);
1733}
1734
1735static int aio_poll(struct aio_kiocb *aiocb, const struct iocb *iocb)
1736{
1737 struct kioctx *ctx = aiocb->ki_ctx;
1738 struct poll_iocb *req = &aiocb->poll;
1739 struct aio_poll_table apt;
1740 bool cancel = false;
1741 __poll_t mask;
1742
1743
1744 if ((u16)iocb->aio_buf != iocb->aio_buf)
1745 return -EINVAL;
1746
1747 if (iocb->aio_offset || iocb->aio_nbytes || iocb->aio_rw_flags)
1748 return -EINVAL;
1749
1750 INIT_WORK(&req->work, aio_poll_complete_work);
1751 req->events = demangle_poll(iocb->aio_buf) | EPOLLERR | EPOLLHUP;
1752
1753 req->head = NULL;
1754 req->done = false;
1755 req->cancelled = false;
1756
1757 apt.pt._qproc = aio_poll_queue_proc;
1758 apt.pt._key = req->events;
1759 apt.iocb = aiocb;
1760 apt.error = -EINVAL;
1761
1762
1763 INIT_LIST_HEAD(&req->wait.entry);
1764 init_waitqueue_func_entry(&req->wait, aio_poll_wake);
1765
1766 mask = vfs_poll(req->file, &apt.pt) & req->events;
1767 spin_lock_irq(&ctx->ctx_lock);
1768 if (likely(req->head)) {
1769 spin_lock(&req->head->lock);
1770 if (unlikely(list_empty(&req->wait.entry))) {
1771 if (apt.error)
1772 cancel = true;
1773 apt.error = 0;
1774 mask = 0;
1775 }
1776 if (mask || apt.error) {
1777 list_del_init(&req->wait.entry);
1778 } else if (cancel) {
1779 WRITE_ONCE(req->cancelled, true);
1780 } else if (!req->done) {
1781 list_add_tail(&aiocb->ki_list, &ctx->active_reqs);
1782 aiocb->ki_cancel = aio_poll_cancel;
1783 }
1784 spin_unlock(&req->head->lock);
1785 }
1786 if (mask) {
1787 aiocb->ki_res.res = mangle_poll(mask);
1788 apt.error = 0;
1789 }
1790 spin_unlock_irq(&ctx->ctx_lock);
1791 if (mask)
1792 iocb_put(aiocb);
1793 return apt.error;
1794}
1795
1796static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
1797 struct iocb __user *user_iocb, struct aio_kiocb *req,
1798 bool compat)
1799{
1800 req->ki_filp = fget(iocb->aio_fildes);
1801 if (unlikely(!req->ki_filp))
1802 return -EBADF;
1803
1804 if (iocb->aio_flags & IOCB_FLAG_RESFD) {
1805 struct eventfd_ctx *eventfd;
1806
1807
1808
1809
1810
1811
1812 eventfd = eventfd_ctx_fdget(iocb->aio_resfd);
1813 if (IS_ERR(eventfd))
1814 return PTR_ERR(eventfd);
1815
1816 req->ki_eventfd = eventfd;
1817 }
1818
1819 if (unlikely(put_user(KIOCB_KEY, &user_iocb->aio_key))) {
1820 pr_debug("EFAULT: aio_key\n");
1821 return -EFAULT;
1822 }
1823
1824 req->ki_res.obj = (u64)(unsigned long)user_iocb;
1825 req->ki_res.data = iocb->aio_data;
1826 req->ki_res.res = 0;
1827 req->ki_res.res2 = 0;
1828
1829 switch (iocb->aio_lio_opcode) {
1830 case IOCB_CMD_PREAD:
1831 return aio_read(&req->rw, iocb, false, compat);
1832 case IOCB_CMD_PWRITE:
1833 return aio_write(&req->rw, iocb, false, compat);
1834 case IOCB_CMD_PREADV:
1835 return aio_read(&req->rw, iocb, true, compat);
1836 case IOCB_CMD_PWRITEV:
1837 return aio_write(&req->rw, iocb, true, compat);
1838 case IOCB_CMD_FSYNC:
1839 return aio_fsync(&req->fsync, iocb, false);
1840 case IOCB_CMD_FDSYNC:
1841 return aio_fsync(&req->fsync, iocb, true);
1842 case IOCB_CMD_POLL:
1843 return aio_poll(req, iocb);
1844 default:
1845 pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode);
1846 return -EINVAL;
1847 }
1848}
1849
1850static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
1851 bool compat)
1852{
1853 struct aio_kiocb *req;
1854 struct iocb iocb;
1855 int err;
1856
1857 if (unlikely(copy_from_user(&iocb, user_iocb, sizeof(iocb))))
1858 return -EFAULT;
1859
1860
1861 if (unlikely(iocb.aio_reserved2)) {
1862 pr_debug("EINVAL: reserve field set\n");
1863 return -EINVAL;
1864 }
1865
1866
1867 if (unlikely(
1868 (iocb.aio_buf != (unsigned long)iocb.aio_buf) ||
1869 (iocb.aio_nbytes != (size_t)iocb.aio_nbytes) ||
1870 ((ssize_t)iocb.aio_nbytes < 0)
1871 )) {
1872 pr_debug("EINVAL: overflow check\n");
1873 return -EINVAL;
1874 }
1875
1876 req = aio_get_req(ctx);
1877 if (unlikely(!req))
1878 return -EAGAIN;
1879
1880 err = __io_submit_one(ctx, &iocb, user_iocb, req, compat);
1881
1882
1883 iocb_put(req);
1884
1885
1886
1887
1888
1889
1890 if (unlikely(err)) {
1891 iocb_destroy(req);
1892 put_reqs_available(ctx, 1);
1893 }
1894 return err;
1895}
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
1910 struct iocb __user * __user *, iocbpp)
1911{
1912 struct kioctx *ctx;
1913 long ret = 0;
1914 int i = 0;
1915 struct blk_plug plug;
1916
1917 if (unlikely(nr < 0))
1918 return -EINVAL;
1919
1920 ctx = lookup_ioctx(ctx_id);
1921 if (unlikely(!ctx)) {
1922 pr_debug("EINVAL: invalid context id\n");
1923 return -EINVAL;
1924 }
1925
1926 if (nr > ctx->nr_events)
1927 nr = ctx->nr_events;
1928
1929 if (nr > AIO_PLUG_THRESHOLD)
1930 blk_start_plug(&plug);
1931 for (i = 0; i < nr; i++) {
1932 struct iocb __user *user_iocb;
1933
1934 if (unlikely(get_user(user_iocb, iocbpp + i))) {
1935 ret = -EFAULT;
1936 break;
1937 }
1938
1939 ret = io_submit_one(ctx, user_iocb, false);
1940 if (ret)
1941 break;
1942 }
1943 if (nr > AIO_PLUG_THRESHOLD)
1944 blk_finish_plug(&plug);
1945
1946 percpu_ref_put(&ctx->users);
1947 return i ? i : ret;
1948}
1949
1950#ifdef CONFIG_COMPAT
1951COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id,
1952 int, nr, compat_uptr_t __user *, iocbpp)
1953{
1954 struct kioctx *ctx;
1955 long ret = 0;
1956 int i = 0;
1957 struct blk_plug plug;
1958
1959 if (unlikely(nr < 0))
1960 return -EINVAL;
1961
1962 ctx = lookup_ioctx(ctx_id);
1963 if (unlikely(!ctx)) {
1964 pr_debug("EINVAL: invalid context id\n");
1965 return -EINVAL;
1966 }
1967
1968 if (nr > ctx->nr_events)
1969 nr = ctx->nr_events;
1970
1971 if (nr > AIO_PLUG_THRESHOLD)
1972 blk_start_plug(&plug);
1973 for (i = 0; i < nr; i++) {
1974 compat_uptr_t user_iocb;
1975
1976 if (unlikely(get_user(user_iocb, iocbpp + i))) {
1977 ret = -EFAULT;
1978 break;
1979 }
1980
1981 ret = io_submit_one(ctx, compat_ptr(user_iocb), true);
1982 if (ret)
1983 break;
1984 }
1985 if (nr > AIO_PLUG_THRESHOLD)
1986 blk_finish_plug(&plug);
1987
1988 percpu_ref_put(&ctx->users);
1989 return i ? i : ret;
1990}
1991#endif
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
2004 struct io_event __user *, result)
2005{
2006 struct kioctx *ctx;
2007 struct aio_kiocb *kiocb;
2008 int ret = -EINVAL;
2009 u32 key;
2010 u64 obj = (u64)(unsigned long)iocb;
2011
2012 if (unlikely(get_user(key, &iocb->aio_key)))
2013 return -EFAULT;
2014 if (unlikely(key != KIOCB_KEY))
2015 return -EINVAL;
2016
2017 ctx = lookup_ioctx(ctx_id);
2018 if (unlikely(!ctx))
2019 return -EINVAL;
2020
2021 spin_lock_irq(&ctx->ctx_lock);
2022
2023 list_for_each_entry(kiocb, &ctx->active_reqs, ki_list) {
2024 if (kiocb->ki_res.obj == obj) {
2025 ret = kiocb->ki_cancel(&kiocb->rw);
2026 list_del_init(&kiocb->ki_list);
2027 break;
2028 }
2029 }
2030 spin_unlock_irq(&ctx->ctx_lock);
2031
2032 if (!ret) {
2033
2034
2035
2036
2037
2038 ret = -EINPROGRESS;
2039 }
2040
2041 percpu_ref_put(&ctx->users);
2042
2043 return ret;
2044}
2045
2046static long do_io_getevents(aio_context_t ctx_id,
2047 long min_nr,
2048 long nr,
2049 struct io_event __user *events,
2050 struct timespec64 *ts)
2051{
2052 ktime_t until = ts ? timespec64_to_ktime(*ts) : KTIME_MAX;
2053 struct kioctx *ioctx = lookup_ioctx(ctx_id);
2054 long ret = -EINVAL;
2055
2056 if (likely(ioctx)) {
2057 if (likely(min_nr <= nr && min_nr >= 0))
2058 ret = read_events(ioctx, min_nr, nr, events, until);
2059 percpu_ref_put(&ioctx->users);
2060 }
2061
2062 return ret;
2063}
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077#ifdef CONFIG_64BIT
2078
2079SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id,
2080 long, min_nr,
2081 long, nr,
2082 struct io_event __user *, events,
2083 struct __kernel_timespec __user *, timeout)
2084{
2085 struct timespec64 ts;
2086 int ret;
2087
2088 if (timeout && unlikely(get_timespec64(&ts, timeout)))
2089 return -EFAULT;
2090
2091 ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);
2092 if (!ret && signal_pending(current))
2093 ret = -EINTR;
2094 return ret;
2095}
2096
2097#endif
2098
2099struct __aio_sigset {
2100 const sigset_t __user *sigmask;
2101 size_t sigsetsize;
2102};
2103
2104SYSCALL_DEFINE6(io_pgetevents,
2105 aio_context_t, ctx_id,
2106 long, min_nr,
2107 long, nr,
2108 struct io_event __user *, events,
2109 struct __kernel_timespec __user *, timeout,
2110 const struct __aio_sigset __user *, usig)
2111{
2112 struct __aio_sigset ksig = { NULL, };
2113 struct timespec64 ts;
2114 bool interrupted;
2115 int ret;
2116
2117 if (timeout && unlikely(get_timespec64(&ts, timeout)))
2118 return -EFAULT;
2119
2120 if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))
2121 return -EFAULT;
2122
2123 ret = set_user_sigmask(ksig.sigmask, ksig.sigsetsize);
2124 if (ret)
2125 return ret;
2126
2127 ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);
2128
2129 interrupted = signal_pending(current);
2130 restore_saved_sigmask_unless(interrupted);
2131 if (interrupted && !ret)
2132 ret = -ERESTARTNOHAND;
2133
2134 return ret;
2135}
2136
2137#if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT)
2138
2139SYSCALL_DEFINE6(io_pgetevents_time32,
2140 aio_context_t, ctx_id,
2141 long, min_nr,
2142 long, nr,
2143 struct io_event __user *, events,
2144 struct old_timespec32 __user *, timeout,
2145 const struct __aio_sigset __user *, usig)
2146{
2147 struct __aio_sigset ksig = { NULL, };
2148 struct timespec64 ts;
2149 bool interrupted;
2150 int ret;
2151
2152 if (timeout && unlikely(get_old_timespec32(&ts, timeout)))
2153 return -EFAULT;
2154
2155 if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))
2156 return -EFAULT;
2157
2158
2159 ret = set_user_sigmask(ksig.sigmask, ksig.sigsetsize);
2160 if (ret)
2161 return ret;
2162
2163 ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);
2164
2165 interrupted = signal_pending(current);
2166 restore_saved_sigmask_unless(interrupted);
2167 if (interrupted && !ret)
2168 ret = -ERESTARTNOHAND;
2169
2170 return ret;
2171}
2172
2173#endif
2174
2175#if defined(CONFIG_COMPAT_32BIT_TIME)
2176
2177SYSCALL_DEFINE5(io_getevents_time32, __u32, ctx_id,
2178 __s32, min_nr,
2179 __s32, nr,
2180 struct io_event __user *, events,
2181 struct old_timespec32 __user *, timeout)
2182{
2183 struct timespec64 t;
2184 int ret;
2185
2186 if (timeout && get_old_timespec32(&t, timeout))
2187 return -EFAULT;
2188
2189 ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL);
2190 if (!ret && signal_pending(current))
2191 ret = -EINTR;
2192 return ret;
2193}
2194
2195#endif
2196
2197#ifdef CONFIG_COMPAT
2198
2199struct __compat_aio_sigset {
2200 compat_uptr_t sigmask;
2201 compat_size_t sigsetsize;
2202};
2203
2204#if defined(CONFIG_COMPAT_32BIT_TIME)
2205
2206COMPAT_SYSCALL_DEFINE6(io_pgetevents,
2207 compat_aio_context_t, ctx_id,
2208 compat_long_t, min_nr,
2209 compat_long_t, nr,
2210 struct io_event __user *, events,
2211 struct old_timespec32 __user *, timeout,
2212 const struct __compat_aio_sigset __user *, usig)
2213{
2214 struct __compat_aio_sigset ksig = { 0, };
2215 struct timespec64 t;
2216 bool interrupted;
2217 int ret;
2218
2219 if (timeout && get_old_timespec32(&t, timeout))
2220 return -EFAULT;
2221
2222 if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))
2223 return -EFAULT;
2224
2225 ret = set_compat_user_sigmask(compat_ptr(ksig.sigmask), ksig.sigsetsize);
2226 if (ret)
2227 return ret;
2228
2229 ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL);
2230
2231 interrupted = signal_pending(current);
2232 restore_saved_sigmask_unless(interrupted);
2233 if (interrupted && !ret)
2234 ret = -ERESTARTNOHAND;
2235
2236 return ret;
2237}
2238
2239#endif
2240
2241COMPAT_SYSCALL_DEFINE6(io_pgetevents_time64,
2242 compat_aio_context_t, ctx_id,
2243 compat_long_t, min_nr,
2244 compat_long_t, nr,
2245 struct io_event __user *, events,
2246 struct __kernel_timespec __user *, timeout,
2247 const struct __compat_aio_sigset __user *, usig)
2248{
2249 struct __compat_aio_sigset ksig = { 0, };
2250 struct timespec64 t;
2251 bool interrupted;
2252 int ret;
2253
2254 if (timeout && get_timespec64(&t, timeout))
2255 return -EFAULT;
2256
2257 if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))
2258 return -EFAULT;
2259
2260 ret = set_compat_user_sigmask(compat_ptr(ksig.sigmask), ksig.sigsetsize);
2261 if (ret)
2262 return ret;
2263
2264 ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL);
2265
2266 interrupted = signal_pending(current);
2267 restore_saved_sigmask_unless(interrupted);
2268 if (interrupted && !ret)
2269 ret = -ERESTARTNOHAND;
2270
2271 return ret;
2272}
2273#endif
2274