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10
11#define pr_fmt(fmt) "%s: " fmt, __func__
12
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/errno.h>
16#include <linux/time.h>
17#include <linux/aio_abi.h>
18#include <linux/export.h>
19#include <linux/syscalls.h>
20#include <linux/backing-dev.h>
21#include <linux/uio.h>
22
23#include <linux/sched/signal.h>
24#include <linux/fs.h>
25#include <linux/file.h>
26#include <linux/mm.h>
27#include <linux/mman.h>
28#include <linux/mmu_context.h>
29#include <linux/percpu.h>
30#include <linux/slab.h>
31#include <linux/timer.h>
32#include <linux/aio.h>
33#include <linux/highmem.h>
34#include <linux/workqueue.h>
35#include <linux/security.h>
36#include <linux/eventfd.h>
37#include <linux/blkdev.h>
38#include <linux/compat.h>
39#include <linux/migrate.h>
40#include <linux/ramfs.h>
41#include <linux/percpu-refcount.h>
42#include <linux/mount.h>
43
44#include <asm/kmap_types.h>
45#include <linux/uaccess.h>
46
47#include "internal.h"
48
49#define AIO_RING_MAGIC 0xa10a10a1
50#define AIO_RING_COMPAT_FEATURES 1
51#define AIO_RING_INCOMPAT_FEATURES 0
52struct aio_ring {
53 unsigned id;
54 unsigned nr;
55 unsigned head;
56
57 unsigned tail;
58
59 unsigned magic;
60 unsigned compat_features;
61 unsigned incompat_features;
62 unsigned header_length;
63
64
65 struct io_event io_events[0];
66};
67
68#define AIO_RING_PAGES 8
69
70struct kioctx_table {
71 struct rcu_head rcu;
72 unsigned nr;
73 struct kioctx *table[];
74};
75
76struct kioctx_cpu {
77 unsigned reqs_available;
78};
79
80struct ctx_rq_wait {
81 struct completion comp;
82 atomic_t count;
83};
84
85struct kioctx {
86 struct percpu_ref users;
87 atomic_t dead;
88
89 struct percpu_ref reqs;
90
91 unsigned long user_id;
92
93 struct __percpu kioctx_cpu *cpu;
94
95
96
97
98
99 unsigned req_batch;
100
101
102
103
104
105
106
107 unsigned max_reqs;
108
109
110 unsigned nr_events;
111
112 unsigned long mmap_base;
113 unsigned long mmap_size;
114
115 struct page **ring_pages;
116 long nr_pages;
117
118 struct work_struct free_work;
119
120
121
122
123 struct ctx_rq_wait *rq_wait;
124
125 struct {
126
127
128
129
130
131
132
133
134 atomic_t reqs_available;
135 } ____cacheline_aligned_in_smp;
136
137 struct {
138 spinlock_t ctx_lock;
139 struct list_head active_reqs;
140 } ____cacheline_aligned_in_smp;
141
142 struct {
143 struct mutex ring_lock;
144 wait_queue_head_t wait;
145 } ____cacheline_aligned_in_smp;
146
147 struct {
148 unsigned tail;
149 unsigned completed_events;
150 spinlock_t completion_lock;
151 } ____cacheline_aligned_in_smp;
152
153 struct page *internal_pages[AIO_RING_PAGES];
154 struct file *aio_ring_file;
155
156 unsigned id;
157};
158
159
160
161
162
163
164
165
166
167
168
169
170#define KIOCB_CANCELLED ((void *) (~0ULL))
171
172struct aio_kiocb {
173 struct kiocb common;
174
175 struct kioctx *ki_ctx;
176 kiocb_cancel_fn *ki_cancel;
177
178 struct iocb __user *ki_user_iocb;
179 __u64 ki_user_data;
180
181 struct list_head ki_list;
182
183
184
185
186
187
188 struct eventfd_ctx *ki_eventfd;
189};
190
191
192static DEFINE_SPINLOCK(aio_nr_lock);
193unsigned long aio_nr;
194unsigned long aio_max_nr = 0x10000;
195
196
197static struct kmem_cache *kiocb_cachep;
198static struct kmem_cache *kioctx_cachep;
199
200static struct vfsmount *aio_mnt;
201
202static const struct file_operations aio_ring_fops;
203static const struct address_space_operations aio_ctx_aops;
204
205static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
206{
207 struct qstr this = QSTR_INIT("[aio]", 5);
208 struct file *file;
209 struct path path;
210 struct inode *inode = alloc_anon_inode(aio_mnt->mnt_sb);
211 if (IS_ERR(inode))
212 return ERR_CAST(inode);
213
214 inode->i_mapping->a_ops = &aio_ctx_aops;
215 inode->i_mapping->private_data = ctx;
216 inode->i_size = PAGE_SIZE * nr_pages;
217
218 path.dentry = d_alloc_pseudo(aio_mnt->mnt_sb, &this);
219 if (!path.dentry) {
220 iput(inode);
221 return ERR_PTR(-ENOMEM);
222 }
223 path.mnt = mntget(aio_mnt);
224
225 d_instantiate(path.dentry, inode);
226 file = alloc_file(&path, FMODE_READ | FMODE_WRITE, &aio_ring_fops);
227 if (IS_ERR(file)) {
228 path_put(&path);
229 return file;
230 }
231
232 file->f_flags = O_RDWR;
233 return file;
234}
235
236static struct dentry *aio_mount(struct file_system_type *fs_type,
237 int flags, const char *dev_name, void *data)
238{
239 static const struct dentry_operations ops = {
240 .d_dname = simple_dname,
241 };
242 struct dentry *root = mount_pseudo(fs_type, "aio:", NULL, &ops,
243 AIO_RING_MAGIC);
244
245 if (!IS_ERR(root))
246 root->d_sb->s_iflags |= SB_I_NOEXEC;
247 return root;
248}
249
250
251
252
253
254static int __init aio_setup(void)
255{
256 static struct file_system_type aio_fs = {
257 .name = "aio",
258 .mount = aio_mount,
259 .kill_sb = kill_anon_super,
260 };
261 aio_mnt = kern_mount(&aio_fs);
262 if (IS_ERR(aio_mnt))
263 panic("Failed to create aio fs mount.");
264
265 kiocb_cachep = KMEM_CACHE(aio_kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
266 kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
267
268 pr_debug("sizeof(struct page) = %zu\n", sizeof(struct page));
269
270 return 0;
271}
272__initcall(aio_setup);
273
274static void put_aio_ring_file(struct kioctx *ctx)
275{
276 struct file *aio_ring_file = ctx->aio_ring_file;
277 struct address_space *i_mapping;
278
279 if (aio_ring_file) {
280 truncate_setsize(file_inode(aio_ring_file), 0);
281
282
283 i_mapping = aio_ring_file->f_mapping;
284 spin_lock(&i_mapping->private_lock);
285 i_mapping->private_data = NULL;
286 ctx->aio_ring_file = NULL;
287 spin_unlock(&i_mapping->private_lock);
288
289 fput(aio_ring_file);
290 }
291}
292
293static void aio_free_ring(struct kioctx *ctx)
294{
295 int i;
296
297
298
299
300 put_aio_ring_file(ctx);
301
302 for (i = 0; i < ctx->nr_pages; i++) {
303 struct page *page;
304 pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i,
305 page_count(ctx->ring_pages[i]));
306 page = ctx->ring_pages[i];
307 if (!page)
308 continue;
309 ctx->ring_pages[i] = NULL;
310 put_page(page);
311 }
312
313 if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages) {
314 kfree(ctx->ring_pages);
315 ctx->ring_pages = NULL;
316 }
317}
318
319static int aio_ring_mremap(struct vm_area_struct *vma)
320{
321 struct file *file = vma->vm_file;
322 struct mm_struct *mm = vma->vm_mm;
323 struct kioctx_table *table;
324 int i, res = -EINVAL;
325
326 spin_lock(&mm->ioctx_lock);
327 rcu_read_lock();
328 table = rcu_dereference(mm->ioctx_table);
329 for (i = 0; i < table->nr; i++) {
330 struct kioctx *ctx;
331
332 ctx = table->table[i];
333 if (ctx && ctx->aio_ring_file == file) {
334 if (!atomic_read(&ctx->dead)) {
335 ctx->user_id = ctx->mmap_base = vma->vm_start;
336 res = 0;
337 }
338 break;
339 }
340 }
341
342 rcu_read_unlock();
343 spin_unlock(&mm->ioctx_lock);
344 return res;
345}
346
347static const struct vm_operations_struct aio_ring_vm_ops = {
348 .mremap = aio_ring_mremap,
349#if IS_ENABLED(CONFIG_MMU)
350 .fault = filemap_fault,
351 .map_pages = filemap_map_pages,
352 .page_mkwrite = filemap_page_mkwrite,
353#endif
354};
355
356static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
357{
358 vma->vm_flags |= VM_DONTEXPAND;
359 vma->vm_ops = &aio_ring_vm_ops;
360 return 0;
361}
362
363static const struct file_operations aio_ring_fops = {
364 .mmap = aio_ring_mmap,
365};
366
367#if IS_ENABLED(CONFIG_MIGRATION)
368static int aio_migratepage(struct address_space *mapping, struct page *new,
369 struct page *old, enum migrate_mode mode)
370{
371 struct kioctx *ctx;
372 unsigned long flags;
373 pgoff_t idx;
374 int rc;
375
376
377
378
379
380
381 if (mode == MIGRATE_SYNC_NO_COPY)
382 return -EINVAL;
383
384 rc = 0;
385
386
387 spin_lock(&mapping->private_lock);
388 ctx = mapping->private_data;
389 if (!ctx) {
390 rc = -EINVAL;
391 goto out;
392 }
393
394
395
396
397
398 if (!mutex_trylock(&ctx->ring_lock)) {
399 rc = -EAGAIN;
400 goto out;
401 }
402
403 idx = old->index;
404 if (idx < (pgoff_t)ctx->nr_pages) {
405
406 if (ctx->ring_pages[idx] != old)
407 rc = -EAGAIN;
408 } else
409 rc = -EINVAL;
410
411 if (rc != 0)
412 goto out_unlock;
413
414
415 BUG_ON(PageWriteback(old));
416 get_page(new);
417
418 rc = migrate_page_move_mapping(mapping, new, old, NULL, mode, 1);
419 if (rc != MIGRATEPAGE_SUCCESS) {
420 put_page(new);
421 goto out_unlock;
422 }
423
424
425
426
427
428 spin_lock_irqsave(&ctx->completion_lock, flags);
429 migrate_page_copy(new, old);
430 BUG_ON(ctx->ring_pages[idx] != old);
431 ctx->ring_pages[idx] = new;
432 spin_unlock_irqrestore(&ctx->completion_lock, flags);
433
434
435 put_page(old);
436
437out_unlock:
438 mutex_unlock(&ctx->ring_lock);
439out:
440 spin_unlock(&mapping->private_lock);
441 return rc;
442}
443#endif
444
445static const struct address_space_operations aio_ctx_aops = {
446 .set_page_dirty = __set_page_dirty_no_writeback,
447#if IS_ENABLED(CONFIG_MIGRATION)
448 .migratepage = aio_migratepage,
449#endif
450};
451
452static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
453{
454 struct aio_ring *ring;
455 struct mm_struct *mm = current->mm;
456 unsigned long size, unused;
457 int nr_pages;
458 int i;
459 struct file *file;
460
461
462 nr_events += 2;
463
464 size = sizeof(struct aio_ring);
465 size += sizeof(struct io_event) * nr_events;
466
467 nr_pages = PFN_UP(size);
468 if (nr_pages < 0)
469 return -EINVAL;
470
471 file = aio_private_file(ctx, nr_pages);
472 if (IS_ERR(file)) {
473 ctx->aio_ring_file = NULL;
474 return -ENOMEM;
475 }
476
477 ctx->aio_ring_file = file;
478 nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring))
479 / sizeof(struct io_event);
480
481 ctx->ring_pages = ctx->internal_pages;
482 if (nr_pages > AIO_RING_PAGES) {
483 ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *),
484 GFP_KERNEL);
485 if (!ctx->ring_pages) {
486 put_aio_ring_file(ctx);
487 return -ENOMEM;
488 }
489 }
490
491 for (i = 0; i < nr_pages; i++) {
492 struct page *page;
493 page = find_or_create_page(file->f_mapping,
494 i, GFP_HIGHUSER | __GFP_ZERO);
495 if (!page)
496 break;
497 pr_debug("pid(%d) page[%d]->count=%d\n",
498 current->pid, i, page_count(page));
499 SetPageUptodate(page);
500 unlock_page(page);
501
502 ctx->ring_pages[i] = page;
503 }
504 ctx->nr_pages = i;
505
506 if (unlikely(i != nr_pages)) {
507 aio_free_ring(ctx);
508 return -ENOMEM;
509 }
510
511 ctx->mmap_size = nr_pages * PAGE_SIZE;
512 pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size);
513
514 if (down_write_killable(&mm->mmap_sem)) {
515 ctx->mmap_size = 0;
516 aio_free_ring(ctx);
517 return -EINTR;
518 }
519
520 ctx->mmap_base = do_mmap_pgoff(ctx->aio_ring_file, 0, ctx->mmap_size,
521 PROT_READ | PROT_WRITE,
522 MAP_SHARED, 0, &unused, NULL);
523 up_write(&mm->mmap_sem);
524 if (IS_ERR((void *)ctx->mmap_base)) {
525 ctx->mmap_size = 0;
526 aio_free_ring(ctx);
527 return -ENOMEM;
528 }
529
530 pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base);
531
532 ctx->user_id = ctx->mmap_base;
533 ctx->nr_events = nr_events;
534
535 ring = kmap_atomic(ctx->ring_pages[0]);
536 ring->nr = nr_events;
537 ring->id = ~0U;
538 ring->head = ring->tail = 0;
539 ring->magic = AIO_RING_MAGIC;
540 ring->compat_features = AIO_RING_COMPAT_FEATURES;
541 ring->incompat_features = AIO_RING_INCOMPAT_FEATURES;
542 ring->header_length = sizeof(struct aio_ring);
543 kunmap_atomic(ring);
544 flush_dcache_page(ctx->ring_pages[0]);
545
546 return 0;
547}
548
549#define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event))
550#define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event))
551#define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE)
552
553void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
554{
555 struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, common);
556 struct kioctx *ctx = req->ki_ctx;
557 unsigned long flags;
558
559 spin_lock_irqsave(&ctx->ctx_lock, flags);
560
561 if (!req->ki_list.next)
562 list_add(&req->ki_list, &ctx->active_reqs);
563
564 req->ki_cancel = cancel;
565
566 spin_unlock_irqrestore(&ctx->ctx_lock, flags);
567}
568EXPORT_SYMBOL(kiocb_set_cancel_fn);
569
570static int kiocb_cancel(struct aio_kiocb *kiocb)
571{
572 kiocb_cancel_fn *old, *cancel;
573
574
575
576
577
578
579 cancel = ACCESS_ONCE(kiocb->ki_cancel);
580 do {
581 if (!cancel || cancel == KIOCB_CANCELLED)
582 return -EINVAL;
583
584 old = cancel;
585 cancel = cmpxchg(&kiocb->ki_cancel, old, KIOCB_CANCELLED);
586 } while (cancel != old);
587
588 return cancel(&kiocb->common);
589}
590
591static void free_ioctx(struct work_struct *work)
592{
593 struct kioctx *ctx = container_of(work, struct kioctx, free_work);
594
595 pr_debug("freeing %p\n", ctx);
596
597 aio_free_ring(ctx);
598 free_percpu(ctx->cpu);
599 percpu_ref_exit(&ctx->reqs);
600 percpu_ref_exit(&ctx->users);
601 kmem_cache_free(kioctx_cachep, ctx);
602}
603
604static void free_ioctx_reqs(struct percpu_ref *ref)
605{
606 struct kioctx *ctx = container_of(ref, struct kioctx, reqs);
607
608
609 if (ctx->rq_wait && atomic_dec_and_test(&ctx->rq_wait->count))
610 complete(&ctx->rq_wait->comp);
611
612 INIT_WORK(&ctx->free_work, free_ioctx);
613 schedule_work(&ctx->free_work);
614}
615
616
617
618
619
620
621static void free_ioctx_users(struct percpu_ref *ref)
622{
623 struct kioctx *ctx = container_of(ref, struct kioctx, users);
624 struct aio_kiocb *req;
625
626 spin_lock_irq(&ctx->ctx_lock);
627
628 while (!list_empty(&ctx->active_reqs)) {
629 req = list_first_entry(&ctx->active_reqs,
630 struct aio_kiocb, ki_list);
631
632 list_del_init(&req->ki_list);
633 kiocb_cancel(req);
634 }
635
636 spin_unlock_irq(&ctx->ctx_lock);
637
638 percpu_ref_kill(&ctx->reqs);
639 percpu_ref_put(&ctx->reqs);
640}
641
642static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm)
643{
644 unsigned i, new_nr;
645 struct kioctx_table *table, *old;
646 struct aio_ring *ring;
647
648 spin_lock(&mm->ioctx_lock);
649 table = rcu_dereference_raw(mm->ioctx_table);
650
651 while (1) {
652 if (table)
653 for (i = 0; i < table->nr; i++)
654 if (!table->table[i]) {
655 ctx->id = i;
656 table->table[i] = ctx;
657 spin_unlock(&mm->ioctx_lock);
658
659
660
661
662
663 ring = kmap_atomic(ctx->ring_pages[0]);
664 ring->id = ctx->id;
665 kunmap_atomic(ring);
666 return 0;
667 }
668
669 new_nr = (table ? table->nr : 1) * 4;
670 spin_unlock(&mm->ioctx_lock);
671
672 table = kzalloc(sizeof(*table) + sizeof(struct kioctx *) *
673 new_nr, GFP_KERNEL);
674 if (!table)
675 return -ENOMEM;
676
677 table->nr = new_nr;
678
679 spin_lock(&mm->ioctx_lock);
680 old = rcu_dereference_raw(mm->ioctx_table);
681
682 if (!old) {
683 rcu_assign_pointer(mm->ioctx_table, table);
684 } else if (table->nr > old->nr) {
685 memcpy(table->table, old->table,
686 old->nr * sizeof(struct kioctx *));
687
688 rcu_assign_pointer(mm->ioctx_table, table);
689 kfree_rcu(old, rcu);
690 } else {
691 kfree(table);
692 table = old;
693 }
694 }
695}
696
697static void aio_nr_sub(unsigned nr)
698{
699 spin_lock(&aio_nr_lock);
700 if (WARN_ON(aio_nr - nr > aio_nr))
701 aio_nr = 0;
702 else
703 aio_nr -= nr;
704 spin_unlock(&aio_nr_lock);
705}
706
707
708
709
710static struct kioctx *ioctx_alloc(unsigned nr_events)
711{
712 struct mm_struct *mm = current->mm;
713 struct kioctx *ctx;
714 int err = -ENOMEM;
715
716
717
718
719
720 unsigned int max_reqs = nr_events;
721
722
723
724
725
726
727
728
729
730
731 nr_events = max(nr_events, num_possible_cpus() * 4);
732 nr_events *= 2;
733
734
735 if (nr_events > (0x10000000U / sizeof(struct io_event))) {
736 pr_debug("ENOMEM: nr_events too high\n");
737 return ERR_PTR(-EINVAL);
738 }
739
740 if (!nr_events || (unsigned long)max_reqs > aio_max_nr)
741 return ERR_PTR(-EAGAIN);
742
743 ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL);
744 if (!ctx)
745 return ERR_PTR(-ENOMEM);
746
747 ctx->max_reqs = max_reqs;
748
749 spin_lock_init(&ctx->ctx_lock);
750 spin_lock_init(&ctx->completion_lock);
751 mutex_init(&ctx->ring_lock);
752
753
754 mutex_lock(&ctx->ring_lock);
755 init_waitqueue_head(&ctx->wait);
756
757 INIT_LIST_HEAD(&ctx->active_reqs);
758
759 if (percpu_ref_init(&ctx->users, free_ioctx_users, 0, GFP_KERNEL))
760 goto err;
761
762 if (percpu_ref_init(&ctx->reqs, free_ioctx_reqs, 0, GFP_KERNEL))
763 goto err;
764
765 ctx->cpu = alloc_percpu(struct kioctx_cpu);
766 if (!ctx->cpu)
767 goto err;
768
769 err = aio_setup_ring(ctx, nr_events);
770 if (err < 0)
771 goto err;
772
773 atomic_set(&ctx->reqs_available, ctx->nr_events - 1);
774 ctx->req_batch = (ctx->nr_events - 1) / (num_possible_cpus() * 4);
775 if (ctx->req_batch < 1)
776 ctx->req_batch = 1;
777
778
779 spin_lock(&aio_nr_lock);
780 if (aio_nr + ctx->max_reqs > aio_max_nr ||
781 aio_nr + ctx->max_reqs < aio_nr) {
782 spin_unlock(&aio_nr_lock);
783 err = -EAGAIN;
784 goto err_ctx;
785 }
786 aio_nr += ctx->max_reqs;
787 spin_unlock(&aio_nr_lock);
788
789 percpu_ref_get(&ctx->users);
790 percpu_ref_get(&ctx->reqs);
791
792 err = ioctx_add_table(ctx, mm);
793 if (err)
794 goto err_cleanup;
795
796
797 mutex_unlock(&ctx->ring_lock);
798
799 pr_debug("allocated ioctx %p[%ld]: mm=%p mask=0x%x\n",
800 ctx, ctx->user_id, mm, ctx->nr_events);
801 return ctx;
802
803err_cleanup:
804 aio_nr_sub(ctx->max_reqs);
805err_ctx:
806 atomic_set(&ctx->dead, 1);
807 if (ctx->mmap_size)
808 vm_munmap(ctx->mmap_base, ctx->mmap_size);
809 aio_free_ring(ctx);
810err:
811 mutex_unlock(&ctx->ring_lock);
812 free_percpu(ctx->cpu);
813 percpu_ref_exit(&ctx->reqs);
814 percpu_ref_exit(&ctx->users);
815 kmem_cache_free(kioctx_cachep, ctx);
816 pr_debug("error allocating ioctx %d\n", err);
817 return ERR_PTR(err);
818}
819
820
821
822
823
824
825static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
826 struct ctx_rq_wait *wait)
827{
828 struct kioctx_table *table;
829
830 spin_lock(&mm->ioctx_lock);
831 if (atomic_xchg(&ctx->dead, 1)) {
832 spin_unlock(&mm->ioctx_lock);
833 return -EINVAL;
834 }
835
836 table = rcu_dereference_raw(mm->ioctx_table);
837 WARN_ON(ctx != table->table[ctx->id]);
838 table->table[ctx->id] = NULL;
839 spin_unlock(&mm->ioctx_lock);
840
841
842 wake_up_all(&ctx->wait);
843
844
845
846
847
848
849
850
851 aio_nr_sub(ctx->max_reqs);
852
853 if (ctx->mmap_size)
854 vm_munmap(ctx->mmap_base, ctx->mmap_size);
855
856 ctx->rq_wait = wait;
857 percpu_ref_kill(&ctx->users);
858 return 0;
859}
860
861
862
863
864
865
866
867
868
869void exit_aio(struct mm_struct *mm)
870{
871 struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table);
872 struct ctx_rq_wait wait;
873 int i, skipped;
874
875 if (!table)
876 return;
877
878 atomic_set(&wait.count, table->nr);
879 init_completion(&wait.comp);
880
881 skipped = 0;
882 for (i = 0; i < table->nr; ++i) {
883 struct kioctx *ctx = table->table[i];
884
885 if (!ctx) {
886 skipped++;
887 continue;
888 }
889
890
891
892
893
894
895
896
897 ctx->mmap_size = 0;
898 kill_ioctx(mm, ctx, &wait);
899 }
900
901 if (!atomic_sub_and_test(skipped, &wait.count)) {
902
903 wait_for_completion(&wait.comp);
904 }
905
906 RCU_INIT_POINTER(mm->ioctx_table, NULL);
907 kfree(table);
908}
909
910static void put_reqs_available(struct kioctx *ctx, unsigned nr)
911{
912 struct kioctx_cpu *kcpu;
913 unsigned long flags;
914
915 local_irq_save(flags);
916 kcpu = this_cpu_ptr(ctx->cpu);
917 kcpu->reqs_available += nr;
918
919 while (kcpu->reqs_available >= ctx->req_batch * 2) {
920 kcpu->reqs_available -= ctx->req_batch;
921 atomic_add(ctx->req_batch, &ctx->reqs_available);
922 }
923
924 local_irq_restore(flags);
925}
926
927static bool get_reqs_available(struct kioctx *ctx)
928{
929 struct kioctx_cpu *kcpu;
930 bool ret = false;
931 unsigned long flags;
932
933 local_irq_save(flags);
934 kcpu = this_cpu_ptr(ctx->cpu);
935 if (!kcpu->reqs_available) {
936 int old, avail = atomic_read(&ctx->reqs_available);
937
938 do {
939 if (avail < ctx->req_batch)
940 goto out;
941
942 old = avail;
943 avail = atomic_cmpxchg(&ctx->reqs_available,
944 avail, avail - ctx->req_batch);
945 } while (avail != old);
946
947 kcpu->reqs_available += ctx->req_batch;
948 }
949
950 ret = true;
951 kcpu->reqs_available--;
952out:
953 local_irq_restore(flags);
954 return ret;
955}
956
957
958
959
960
961
962
963
964static void refill_reqs_available(struct kioctx *ctx, unsigned head,
965 unsigned tail)
966{
967 unsigned events_in_ring, completed;
968
969
970 head %= ctx->nr_events;
971 if (head <= tail)
972 events_in_ring = tail - head;
973 else
974 events_in_ring = ctx->nr_events - (head - tail);
975
976 completed = ctx->completed_events;
977 if (events_in_ring < completed)
978 completed -= events_in_ring;
979 else
980 completed = 0;
981
982 if (!completed)
983 return;
984
985 ctx->completed_events -= completed;
986 put_reqs_available(ctx, completed);
987}
988
989
990
991
992
993static void user_refill_reqs_available(struct kioctx *ctx)
994{
995 spin_lock_irq(&ctx->completion_lock);
996 if (ctx->completed_events) {
997 struct aio_ring *ring;
998 unsigned head;
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009 ring = kmap_atomic(ctx->ring_pages[0]);
1010 head = ring->head;
1011 kunmap_atomic(ring);
1012
1013 refill_reqs_available(ctx, head, ctx->tail);
1014 }
1015
1016 spin_unlock_irq(&ctx->completion_lock);
1017}
1018
1019
1020
1021
1022
1023static inline struct aio_kiocb *aio_get_req(struct kioctx *ctx)
1024{
1025 struct aio_kiocb *req;
1026
1027 if (!get_reqs_available(ctx)) {
1028 user_refill_reqs_available(ctx);
1029 if (!get_reqs_available(ctx))
1030 return NULL;
1031 }
1032
1033 req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
1034 if (unlikely(!req))
1035 goto out_put;
1036
1037 percpu_ref_get(&ctx->reqs);
1038
1039 req->ki_ctx = ctx;
1040 return req;
1041out_put:
1042 put_reqs_available(ctx, 1);
1043 return NULL;
1044}
1045
1046static void kiocb_free(struct aio_kiocb *req)
1047{
1048 if (req->common.ki_filp)
1049 fput(req->common.ki_filp);
1050 if (req->ki_eventfd != NULL)
1051 eventfd_ctx_put(req->ki_eventfd);
1052 kmem_cache_free(kiocb_cachep, req);
1053}
1054
1055static struct kioctx *lookup_ioctx(unsigned long ctx_id)
1056{
1057 struct aio_ring __user *ring = (void __user *)ctx_id;
1058 struct mm_struct *mm = current->mm;
1059 struct kioctx *ctx, *ret = NULL;
1060 struct kioctx_table *table;
1061 unsigned id;
1062
1063 if (get_user(id, &ring->id))
1064 return NULL;
1065
1066 rcu_read_lock();
1067 table = rcu_dereference(mm->ioctx_table);
1068
1069 if (!table || id >= table->nr)
1070 goto out;
1071
1072 ctx = table->table[id];
1073 if (ctx && ctx->user_id == ctx_id) {
1074 percpu_ref_get(&ctx->users);
1075 ret = ctx;
1076 }
1077out:
1078 rcu_read_unlock();
1079 return ret;
1080}
1081
1082
1083
1084
1085static void aio_complete(struct kiocb *kiocb, long res, long res2)
1086{
1087 struct aio_kiocb *iocb = container_of(kiocb, struct aio_kiocb, common);
1088 struct kioctx *ctx = iocb->ki_ctx;
1089 struct aio_ring *ring;
1090 struct io_event *ev_page, *event;
1091 unsigned tail, pos, head;
1092 unsigned long flags;
1093
1094 if (kiocb->ki_flags & IOCB_WRITE) {
1095 struct file *file = kiocb->ki_filp;
1096
1097
1098
1099
1100
1101 if (S_ISREG(file_inode(file)->i_mode))
1102 __sb_writers_acquired(file_inode(file)->i_sb, SB_FREEZE_WRITE);
1103 file_end_write(file);
1104 }
1105
1106
1107
1108
1109
1110
1111
1112
1113 BUG_ON(is_sync_kiocb(kiocb));
1114
1115 if (iocb->ki_list.next) {
1116 unsigned long flags;
1117
1118 spin_lock_irqsave(&ctx->ctx_lock, flags);
1119 list_del(&iocb->ki_list);
1120 spin_unlock_irqrestore(&ctx->ctx_lock, flags);
1121 }
1122
1123
1124
1125
1126
1127
1128 spin_lock_irqsave(&ctx->completion_lock, flags);
1129
1130 tail = ctx->tail;
1131 pos = tail + AIO_EVENTS_OFFSET;
1132
1133 if (++tail >= ctx->nr_events)
1134 tail = 0;
1135
1136 ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
1137 event = ev_page + pos % AIO_EVENTS_PER_PAGE;
1138
1139 event->obj = (u64)(unsigned long)iocb->ki_user_iocb;
1140 event->data = iocb->ki_user_data;
1141 event->res = res;
1142 event->res2 = res2;
1143
1144 kunmap_atomic(ev_page);
1145 flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
1146
1147 pr_debug("%p[%u]: %p: %p %Lx %lx %lx\n",
1148 ctx, tail, iocb, iocb->ki_user_iocb, iocb->ki_user_data,
1149 res, res2);
1150
1151
1152
1153
1154 smp_wmb();
1155
1156 ctx->tail = tail;
1157
1158 ring = kmap_atomic(ctx->ring_pages[0]);
1159 head = ring->head;
1160 ring->tail = tail;
1161 kunmap_atomic(ring);
1162 flush_dcache_page(ctx->ring_pages[0]);
1163
1164 ctx->completed_events++;
1165 if (ctx->completed_events > 1)
1166 refill_reqs_available(ctx, head, tail);
1167 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1168
1169 pr_debug("added to ring %p at [%u]\n", iocb, tail);
1170
1171
1172
1173
1174
1175
1176 if (iocb->ki_eventfd != NULL)
1177 eventfd_signal(iocb->ki_eventfd, 1);
1178
1179
1180 kiocb_free(iocb);
1181
1182
1183
1184
1185
1186
1187
1188 smp_mb();
1189
1190 if (waitqueue_active(&ctx->wait))
1191 wake_up(&ctx->wait);
1192
1193 percpu_ref_put(&ctx->reqs);
1194}
1195
1196
1197
1198
1199
1200static long aio_read_events_ring(struct kioctx *ctx,
1201 struct io_event __user *event, long nr)
1202{
1203 struct aio_ring *ring;
1204 unsigned head, tail, pos;
1205 long ret = 0;
1206 int copy_ret;
1207
1208
1209
1210
1211
1212
1213
1214 sched_annotate_sleep();
1215 mutex_lock(&ctx->ring_lock);
1216
1217
1218 ring = kmap_atomic(ctx->ring_pages[0]);
1219 head = ring->head;
1220 tail = ring->tail;
1221 kunmap_atomic(ring);
1222
1223
1224
1225
1226
1227 smp_rmb();
1228
1229 pr_debug("h%u t%u m%u\n", head, tail, ctx->nr_events);
1230
1231 if (head == tail)
1232 goto out;
1233
1234 head %= ctx->nr_events;
1235 tail %= ctx->nr_events;
1236
1237 while (ret < nr) {
1238 long avail;
1239 struct io_event *ev;
1240 struct page *page;
1241
1242 avail = (head <= tail ? tail : ctx->nr_events) - head;
1243 if (head == tail)
1244 break;
1245
1246 avail = min(avail, nr - ret);
1247 avail = min_t(long, avail, AIO_EVENTS_PER_PAGE -
1248 ((head + AIO_EVENTS_OFFSET) % AIO_EVENTS_PER_PAGE));
1249
1250 pos = head + AIO_EVENTS_OFFSET;
1251 page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE];
1252 pos %= AIO_EVENTS_PER_PAGE;
1253
1254 ev = kmap(page);
1255 copy_ret = copy_to_user(event + ret, ev + pos,
1256 sizeof(*ev) * avail);
1257 kunmap(page);
1258
1259 if (unlikely(copy_ret)) {
1260 ret = -EFAULT;
1261 goto out;
1262 }
1263
1264 ret += avail;
1265 head += avail;
1266 head %= ctx->nr_events;
1267 }
1268
1269 ring = kmap_atomic(ctx->ring_pages[0]);
1270 ring->head = head;
1271 kunmap_atomic(ring);
1272 flush_dcache_page(ctx->ring_pages[0]);
1273
1274 pr_debug("%li h%u t%u\n", ret, head, tail);
1275out:
1276 mutex_unlock(&ctx->ring_lock);
1277
1278 return ret;
1279}
1280
1281static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr,
1282 struct io_event __user *event, long *i)
1283{
1284 long ret = aio_read_events_ring(ctx, event + *i, nr - *i);
1285
1286 if (ret > 0)
1287 *i += ret;
1288
1289 if (unlikely(atomic_read(&ctx->dead)))
1290 ret = -EINVAL;
1291
1292 if (!*i)
1293 *i = ret;
1294
1295 return ret < 0 || *i >= min_nr;
1296}
1297
1298static long read_events(struct kioctx *ctx, long min_nr, long nr,
1299 struct io_event __user *event,
1300 struct timespec __user *timeout)
1301{
1302 ktime_t until = KTIME_MAX;
1303 long ret = 0;
1304
1305 if (timeout) {
1306 struct timespec ts;
1307
1308 if (unlikely(copy_from_user(&ts, timeout, sizeof(ts))))
1309 return -EFAULT;
1310
1311 until = timespec_to_ktime(ts);
1312 }
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328 if (until == 0)
1329 aio_read_events(ctx, min_nr, nr, event, &ret);
1330 else
1331 wait_event_interruptible_hrtimeout(ctx->wait,
1332 aio_read_events(ctx, min_nr, nr, event, &ret),
1333 until);
1334
1335 if (!ret && signal_pending(current))
1336 ret = -EINTR;
1337
1338 return ret;
1339}
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
1355{
1356 struct kioctx *ioctx = NULL;
1357 unsigned long ctx;
1358 long ret;
1359
1360 ret = get_user(ctx, ctxp);
1361 if (unlikely(ret))
1362 goto out;
1363
1364 ret = -EINVAL;
1365 if (unlikely(ctx || nr_events == 0)) {
1366 pr_debug("EINVAL: ctx %lu nr_events %u\n",
1367 ctx, nr_events);
1368 goto out;
1369 }
1370
1371 ioctx = ioctx_alloc(nr_events);
1372 ret = PTR_ERR(ioctx);
1373 if (!IS_ERR(ioctx)) {
1374 ret = put_user(ioctx->user_id, ctxp);
1375 if (ret)
1376 kill_ioctx(current->mm, ioctx, NULL);
1377 percpu_ref_put(&ioctx->users);
1378 }
1379
1380out:
1381 return ret;
1382}
1383
1384#ifdef CONFIG_COMPAT
1385COMPAT_SYSCALL_DEFINE2(io_setup, unsigned, nr_events, u32 __user *, ctx32p)
1386{
1387 struct kioctx *ioctx = NULL;
1388 unsigned long ctx;
1389 long ret;
1390
1391 ret = get_user(ctx, ctx32p);
1392 if (unlikely(ret))
1393 goto out;
1394
1395 ret = -EINVAL;
1396 if (unlikely(ctx || nr_events == 0)) {
1397 pr_debug("EINVAL: ctx %lu nr_events %u\n",
1398 ctx, nr_events);
1399 goto out;
1400 }
1401
1402 ioctx = ioctx_alloc(nr_events);
1403 ret = PTR_ERR(ioctx);
1404 if (!IS_ERR(ioctx)) {
1405
1406 ret = put_user((u32)ioctx->user_id, ctx32p);
1407 if (ret)
1408 kill_ioctx(current->mm, ioctx, NULL);
1409 percpu_ref_put(&ioctx->users);
1410 }
1411
1412out:
1413 return ret;
1414}
1415#endif
1416
1417
1418
1419
1420
1421
1422
1423SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
1424{
1425 struct kioctx *ioctx = lookup_ioctx(ctx);
1426 if (likely(NULL != ioctx)) {
1427 struct ctx_rq_wait wait;
1428 int ret;
1429
1430 init_completion(&wait.comp);
1431 atomic_set(&wait.count, 1);
1432
1433
1434
1435
1436
1437 ret = kill_ioctx(current->mm, ioctx, &wait);
1438 percpu_ref_put(&ioctx->users);
1439
1440
1441
1442
1443
1444 if (!ret)
1445 wait_for_completion(&wait.comp);
1446
1447 return ret;
1448 }
1449 pr_debug("EINVAL: invalid context id\n");
1450 return -EINVAL;
1451}
1452
1453static int aio_setup_rw(int rw, struct iocb *iocb, struct iovec **iovec,
1454 bool vectored, bool compat, struct iov_iter *iter)
1455{
1456 void __user *buf = (void __user *)(uintptr_t)iocb->aio_buf;
1457 size_t len = iocb->aio_nbytes;
1458
1459 if (!vectored) {
1460 ssize_t ret = import_single_range(rw, buf, len, *iovec, iter);
1461 *iovec = NULL;
1462 return ret;
1463 }
1464#ifdef CONFIG_COMPAT
1465 if (compat)
1466 return compat_import_iovec(rw, buf, len, UIO_FASTIOV, iovec,
1467 iter);
1468#endif
1469 return import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter);
1470}
1471
1472static inline ssize_t aio_ret(struct kiocb *req, ssize_t ret)
1473{
1474 switch (ret) {
1475 case -EIOCBQUEUED:
1476 return ret;
1477 case -ERESTARTSYS:
1478 case -ERESTARTNOINTR:
1479 case -ERESTARTNOHAND:
1480 case -ERESTART_RESTARTBLOCK:
1481
1482
1483
1484
1485 ret = -EINTR;
1486
1487 default:
1488 aio_complete(req, ret, 0);
1489 return 0;
1490 }
1491}
1492
1493static ssize_t aio_read(struct kiocb *req, struct iocb *iocb, bool vectored,
1494 bool compat)
1495{
1496 struct file *file = req->ki_filp;
1497 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
1498 struct iov_iter iter;
1499 ssize_t ret;
1500
1501 if (unlikely(!(file->f_mode & FMODE_READ)))
1502 return -EBADF;
1503 if (unlikely(!file->f_op->read_iter))
1504 return -EINVAL;
1505
1506 ret = aio_setup_rw(READ, iocb, &iovec, vectored, compat, &iter);
1507 if (ret)
1508 return ret;
1509 ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter));
1510 if (!ret)
1511 ret = aio_ret(req, call_read_iter(file, req, &iter));
1512 kfree(iovec);
1513 return ret;
1514}
1515
1516static ssize_t aio_write(struct kiocb *req, struct iocb *iocb, bool vectored,
1517 bool compat)
1518{
1519 struct file *file = req->ki_filp;
1520 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
1521 struct iov_iter iter;
1522 ssize_t ret;
1523
1524 if (unlikely(!(file->f_mode & FMODE_WRITE)))
1525 return -EBADF;
1526 if (unlikely(!file->f_op->write_iter))
1527 return -EINVAL;
1528
1529 ret = aio_setup_rw(WRITE, iocb, &iovec, vectored, compat, &iter);
1530 if (ret)
1531 return ret;
1532 ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter));
1533 if (!ret) {
1534 req->ki_flags |= IOCB_WRITE;
1535 file_start_write(file);
1536 ret = aio_ret(req, call_write_iter(file, req, &iter));
1537
1538
1539
1540
1541
1542 if (S_ISREG(file_inode(file)->i_mode))
1543 __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE);
1544 }
1545 kfree(iovec);
1546 return ret;
1547}
1548
1549static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
1550 struct iocb *iocb, bool compat)
1551{
1552 struct aio_kiocb *req;
1553 struct file *file;
1554 ssize_t ret;
1555
1556
1557 if (unlikely(iocb->aio_reserved2)) {
1558 pr_debug("EINVAL: reserve field set\n");
1559 return -EINVAL;
1560 }
1561
1562
1563 if (unlikely(
1564 (iocb->aio_buf != (unsigned long)iocb->aio_buf) ||
1565 (iocb->aio_nbytes != (size_t)iocb->aio_nbytes) ||
1566 ((ssize_t)iocb->aio_nbytes < 0)
1567 )) {
1568 pr_debug("EINVAL: overflow check\n");
1569 return -EINVAL;
1570 }
1571
1572 req = aio_get_req(ctx);
1573 if (unlikely(!req))
1574 return -EAGAIN;
1575
1576 req->common.ki_filp = file = fget(iocb->aio_fildes);
1577 if (unlikely(!req->common.ki_filp)) {
1578 ret = -EBADF;
1579 goto out_put_req;
1580 }
1581 req->common.ki_pos = iocb->aio_offset;
1582 req->common.ki_complete = aio_complete;
1583 req->common.ki_flags = iocb_flags(req->common.ki_filp);
1584 req->common.ki_hint = file_write_hint(file);
1585
1586 if (iocb->aio_flags & IOCB_FLAG_RESFD) {
1587
1588
1589
1590
1591
1592
1593 req->ki_eventfd = eventfd_ctx_fdget((int) iocb->aio_resfd);
1594 if (IS_ERR(req->ki_eventfd)) {
1595 ret = PTR_ERR(req->ki_eventfd);
1596 req->ki_eventfd = NULL;
1597 goto out_put_req;
1598 }
1599
1600 req->common.ki_flags |= IOCB_EVENTFD;
1601 }
1602
1603 ret = kiocb_set_rw_flags(&req->common, iocb->aio_rw_flags);
1604 if (unlikely(ret)) {
1605 pr_debug("EINVAL: aio_rw_flags\n");
1606 goto out_put_req;
1607 }
1608
1609 ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
1610 if (unlikely(ret)) {
1611 pr_debug("EFAULT: aio_key\n");
1612 goto out_put_req;
1613 }
1614
1615 req->ki_user_iocb = user_iocb;
1616 req->ki_user_data = iocb->aio_data;
1617
1618 get_file(file);
1619 switch (iocb->aio_lio_opcode) {
1620 case IOCB_CMD_PREAD:
1621 ret = aio_read(&req->common, iocb, false, compat);
1622 break;
1623 case IOCB_CMD_PWRITE:
1624 ret = aio_write(&req->common, iocb, false, compat);
1625 break;
1626 case IOCB_CMD_PREADV:
1627 ret = aio_read(&req->common, iocb, true, compat);
1628 break;
1629 case IOCB_CMD_PWRITEV:
1630 ret = aio_write(&req->common, iocb, true, compat);
1631 break;
1632 default:
1633 pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode);
1634 ret = -EINVAL;
1635 break;
1636 }
1637 fput(file);
1638
1639 if (ret && ret != -EIOCBQUEUED)
1640 goto out_put_req;
1641 return 0;
1642out_put_req:
1643 put_reqs_available(ctx, 1);
1644 percpu_ref_put(&ctx->reqs);
1645 kiocb_free(req);
1646 return ret;
1647}
1648
1649static long do_io_submit(aio_context_t ctx_id, long nr,
1650 struct iocb __user *__user *iocbpp, bool compat)
1651{
1652 struct kioctx *ctx;
1653 long ret = 0;
1654 int i = 0;
1655 struct blk_plug plug;
1656
1657 if (unlikely(nr < 0))
1658 return -EINVAL;
1659
1660 if (unlikely(nr > LONG_MAX/sizeof(*iocbpp)))
1661 nr = LONG_MAX/sizeof(*iocbpp);
1662
1663 if (unlikely(!access_ok(VERIFY_READ, iocbpp, (nr*sizeof(*iocbpp)))))
1664 return -EFAULT;
1665
1666 ctx = lookup_ioctx(ctx_id);
1667 if (unlikely(!ctx)) {
1668 pr_debug("EINVAL: invalid context id\n");
1669 return -EINVAL;
1670 }
1671
1672 blk_start_plug(&plug);
1673
1674
1675
1676
1677
1678 for (i=0; i<nr; i++) {
1679 struct iocb __user *user_iocb;
1680 struct iocb tmp;
1681
1682 if (unlikely(__get_user(user_iocb, iocbpp + i))) {
1683 ret = -EFAULT;
1684 break;
1685 }
1686
1687 if (unlikely(copy_from_user(&tmp, user_iocb, sizeof(tmp)))) {
1688 ret = -EFAULT;
1689 break;
1690 }
1691
1692 ret = io_submit_one(ctx, user_iocb, &tmp, compat);
1693 if (ret)
1694 break;
1695 }
1696 blk_finish_plug(&plug);
1697
1698 percpu_ref_put(&ctx->users);
1699 return i ? i : ret;
1700}
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
1715 struct iocb __user * __user *, iocbpp)
1716{
1717 return do_io_submit(ctx_id, nr, iocbpp, 0);
1718}
1719
1720#ifdef CONFIG_COMPAT
1721static inline long
1722copy_iocb(long nr, u32 __user *ptr32, struct iocb __user * __user *ptr64)
1723{
1724 compat_uptr_t uptr;
1725 int i;
1726
1727 for (i = 0; i < nr; ++i) {
1728 if (get_user(uptr, ptr32 + i))
1729 return -EFAULT;
1730 if (put_user(compat_ptr(uptr), ptr64 + i))
1731 return -EFAULT;
1732 }
1733 return 0;
1734}
1735
1736#define MAX_AIO_SUBMITS (PAGE_SIZE/sizeof(struct iocb *))
1737
1738COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id,
1739 int, nr, u32 __user *, iocb)
1740{
1741 struct iocb __user * __user *iocb64;
1742 long ret;
1743
1744 if (unlikely(nr < 0))
1745 return -EINVAL;
1746
1747 if (nr > MAX_AIO_SUBMITS)
1748 nr = MAX_AIO_SUBMITS;
1749
1750 iocb64 = compat_alloc_user_space(nr * sizeof(*iocb64));
1751 ret = copy_iocb(nr, iocb, iocb64);
1752 if (!ret)
1753 ret = do_io_submit(ctx_id, nr, iocb64, 1);
1754 return ret;
1755}
1756#endif
1757
1758
1759
1760
1761static struct aio_kiocb *
1762lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb, u32 key)
1763{
1764 struct aio_kiocb *kiocb;
1765
1766 assert_spin_locked(&ctx->ctx_lock);
1767
1768 if (key != KIOCB_KEY)
1769 return NULL;
1770
1771
1772 list_for_each_entry(kiocb, &ctx->active_reqs, ki_list) {
1773 if (kiocb->ki_user_iocb == iocb)
1774 return kiocb;
1775 }
1776 return NULL;
1777}
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
1790 struct io_event __user *, result)
1791{
1792 struct kioctx *ctx;
1793 struct aio_kiocb *kiocb;
1794 u32 key;
1795 int ret;
1796
1797 ret = get_user(key, &iocb->aio_key);
1798 if (unlikely(ret))
1799 return -EFAULT;
1800
1801 ctx = lookup_ioctx(ctx_id);
1802 if (unlikely(!ctx))
1803 return -EINVAL;
1804
1805 spin_lock_irq(&ctx->ctx_lock);
1806
1807 kiocb = lookup_kiocb(ctx, iocb, key);
1808 if (kiocb)
1809 ret = kiocb_cancel(kiocb);
1810 else
1811 ret = -EINVAL;
1812
1813 spin_unlock_irq(&ctx->ctx_lock);
1814
1815 if (!ret) {
1816
1817
1818
1819
1820
1821 ret = -EINPROGRESS;
1822 }
1823
1824 percpu_ref_put(&ctx->users);
1825
1826 return ret;
1827}
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id,
1842 long, min_nr,
1843 long, nr,
1844 struct io_event __user *, events,
1845 struct timespec __user *, timeout)
1846{
1847 struct kioctx *ioctx = lookup_ioctx(ctx_id);
1848 long ret = -EINVAL;
1849
1850 if (likely(ioctx)) {
1851 if (likely(min_nr <= nr && min_nr >= 0))
1852 ret = read_events(ioctx, min_nr, nr, events, timeout);
1853 percpu_ref_put(&ioctx->users);
1854 }
1855 return ret;
1856}
1857
1858#ifdef CONFIG_COMPAT
1859COMPAT_SYSCALL_DEFINE5(io_getevents, compat_aio_context_t, ctx_id,
1860 compat_long_t, min_nr,
1861 compat_long_t, nr,
1862 struct io_event __user *, events,
1863 struct compat_timespec __user *, timeout)
1864{
1865 struct timespec t;
1866 struct timespec __user *ut = NULL;
1867
1868 if (timeout) {
1869 if (compat_get_timespec(&t, timeout))
1870 return -EFAULT;
1871
1872 ut = compat_alloc_user_space(sizeof(*ut));
1873 if (copy_to_user(ut, &t, sizeof(t)))
1874 return -EFAULT;
1875 }
1876 return sys_io_getevents(ctx_id, min_nr, nr, events, ut);
1877}
1878#endif
1879