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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * mm/userfaultfd.c
4 *
5 * Copyright (C) 2015 Red Hat, Inc.
6 */
7
8 #include <linux/mm.h>
9 #include <linux/sched/signal.h>
10 #include <linux/pagemap.h>
11 #include <linux/rmap.h>
12 #include <linux/swap.h>
13 #include <linux/swapops.h>
14 #include <linux/userfaultfd_k.h>
15 #include <linux/mmu_notifier.h>
16 #include <linux/hugetlb.h>
17 #include <linux/shmem_fs.h>
18 #include <asm/tlbflush.h>
19 #include "internal.h"
20
21 static __always_inline
22 struct vm_area_struct *find_dst_vma(struct mm_struct *dst_mm,
23 unsigned long dst_start,
24 unsigned long len)
25 {
26 /*
27 * Make sure that the dst range is both valid and fully within a
28 * single existing vma.
29 */
30 struct vm_area_struct *dst_vma;
31
32 dst_vma = find_vma(dst_mm, dst_start);
33 if (!dst_vma)
34 return NULL;
35
36 if (dst_start < dst_vma->vm_start ||
37 dst_start + len > dst_vma->vm_end)
38 return NULL;
39
40 /*
41 * Check the vma is registered in uffd, this is required to
42 * enforce the VM_MAYWRITE check done at uffd registration
43 * time.
44 */
45 if (!dst_vma->vm_userfaultfd_ctx.ctx)
46 return NULL;
47
48 return dst_vma;
49 }
50
51 static int mcopy_atomic_pte(struct mm_struct *dst_mm,
52 pmd_t *dst_pmd,
53 struct vm_area_struct *dst_vma,
54 unsigned long dst_addr,
55 unsigned long src_addr,
56 struct page **pagep,
57 bool wp_copy)
58 {
59 pte_t _dst_pte, *dst_pte;
60 spinlock_t *ptl;
61 void *page_kaddr;
62 int ret;
63 struct page *page;
64 pgoff_t offset, max_off;
65 struct inode *inode;
66
67 if (!*pagep) {
68 ret = -ENOMEM;
69 page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, dst_vma, dst_addr);
70 if (!page)
71 goto out;
72
73 page_kaddr = kmap_atomic(page);
74 ret = copy_from_user(page_kaddr,
75 (const void __user *) src_addr,
76 PAGE_SIZE);
77 kunmap_atomic(page_kaddr);
78
79 /* fallback to copy_from_user outside mmap_lock */
80 if (unlikely(ret)) {
81 ret = -ENOENT;
82 *pagep = page;
83 /* don't free the page */
84 goto out;
85 }
86 } else {
87 page = *pagep;
88 *pagep = NULL;
89 }
90
91 /*
92 * The memory barrier inside __SetPageUptodate makes sure that
93 * preceding stores to the page contents become visible before
94 * the set_pte_at() write.
95 */
96 __SetPageUptodate(page);
97
98 ret = -ENOMEM;
99 if (mem_cgroup_charge(page, dst_mm, GFP_KERNEL))
100 goto out_release;
101
102 _dst_pte = pte_mkdirty(mk_pte(page, dst_vma->vm_page_prot));
103 if (dst_vma->vm_flags & VM_WRITE) {
104 if (wp_copy)
105 _dst_pte = pte_mkuffd_wp(_dst_pte);
106 else
107 _dst_pte = pte_mkwrite(_dst_pte);
108 }
109
110 dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
111 if (dst_vma->vm_file) {
112 /* the shmem MAP_PRIVATE case requires checking the i_size */
113 inode = dst_vma->vm_file->f_inode;
114 offset = linear_page_index(dst_vma, dst_addr);
115 max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
116 ret = -EFAULT;
117 if (unlikely(offset >= max_off))
118 goto out_release_uncharge_unlock;
119 }
120 ret = -EEXIST;
121 if (!pte_none(*dst_pte))
122 goto out_release_uncharge_unlock;
123
124 inc_mm_counter(dst_mm, MM_ANONPAGES);
125 page_add_new_anon_rmap(page, dst_vma, dst_addr, false);
126 lru_cache_add_inactive_or_unevictable(page, dst_vma);
127
128 set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
129
130 /* No need to invalidate - it was non-present before */
131 update_mmu_cache(dst_vma, dst_addr, dst_pte);
132
133 pte_unmap_unlock(dst_pte, ptl);
134 ret = 0;
135 out:
136 return ret;
137 out_release_uncharge_unlock:
138 pte_unmap_unlock(dst_pte, ptl);
139 out_release:
140 put_page(page);
141 goto out;
142 }
143
144 static int mfill_zeropage_pte(struct mm_struct *dst_mm,
145 pmd_t *dst_pmd,
146 struct vm_area_struct *dst_vma,
147 unsigned long dst_addr)
148 {
149 pte_t _dst_pte, *dst_pte;
150 spinlock_t *ptl;
151 int ret;
152 pgoff_t offset, max_off;
153 struct inode *inode;
154
155 _dst_pte = pte_mkspecial(pfn_pte(my_zero_pfn(dst_addr),
156 dst_vma->vm_page_prot));
157 dst_pte = pte_offset_map_lock(dst_mm, dst_pmd, dst_addr, &ptl);
158 if (dst_vma->vm_file) {
159 /* the shmem MAP_PRIVATE case requires checking the i_size */
160 inode = dst_vma->vm_file->f_inode;
161 offset = linear_page_index(dst_vma, dst_addr);
162 max_off = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
163 ret = -EFAULT;
164 if (unlikely(offset >= max_off))
165 goto out_unlock;
166 }
167 ret = -EEXIST;
168 if (!pte_none(*dst_pte))
169 goto out_unlock;
170 set_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
171 /* No need to invalidate - it was non-present before */
172 update_mmu_cache(dst_vma, dst_addr, dst_pte);
173 ret = 0;
174 out_unlock:
175 pte_unmap_unlock(dst_pte, ptl);
176 return ret;
177 }
178
179 static pmd_t *mm_alloc_pmd(struct mm_struct *mm, unsigned long address)
180 {
181 pgd_t *pgd;
182 p4d_t *p4d;
183 pud_t *pud;
184
185 pgd = pgd_offset(mm, address);
186 p4d = p4d_alloc(mm, pgd, address);
187 if (!p4d)
188 return NULL;
189 pud = pud_alloc(mm, p4d, address);
190 if (!pud)
191 return NULL;
192 /*
193 * Note that we didn't run this because the pmd was
194 * missing, the *pmd may be already established and in
195 * turn it may also be a trans_huge_pmd.
196 */
197 return pmd_alloc(mm, pud, address);
198 }
199
200 #ifdef CONFIG_HUGETLB_PAGE
201 /*
202 * __mcopy_atomic processing for HUGETLB vmas. Note that this routine is
203 * called with mmap_lock held, it will release mmap_lock before returning.
204 */
205 static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
206 struct vm_area_struct *dst_vma,
207 unsigned long dst_start,
208 unsigned long src_start,
209 unsigned long len,
210 enum mcopy_atomic_mode mode)
211 {
212 int vm_alloc_shared = dst_vma->vm_flags & VM_SHARED;
213 int vm_shared = dst_vma->vm_flags & VM_SHARED;
214 ssize_t err;
215 pte_t *dst_pte;
216 unsigned long src_addr, dst_addr;
217 long copied;
218 struct page *page;
219 unsigned long vma_hpagesize;
220 pgoff_t idx;
221 u32 hash;
222 struct address_space *mapping;
223
224 /*
225 * There is no default zero huge page for all huge page sizes as
226 * supported by hugetlb. A PMD_SIZE huge pages may exist as used
227 * by THP. Since we can not reliably insert a zero page, this
228 * feature is not supported.
229 */
230 if (mode == MCOPY_ATOMIC_ZEROPAGE) {
231 mmap_read_unlock(dst_mm);
232 return -EINVAL;
233 }
234
235 src_addr = src_start;
236 dst_addr = dst_start;
237 copied = 0;
238 page = NULL;
239 vma_hpagesize = vma_kernel_pagesize(dst_vma);
240
241 /*
242 * Validate alignment based on huge page size
243 */
244 err = -EINVAL;
245 if (dst_start & (vma_hpagesize - 1) || len & (vma_hpagesize - 1))
246 goto out_unlock;
247
248 retry:
249 /*
250 * On routine entry dst_vma is set. If we had to drop mmap_lock and
251 * retry, dst_vma will be set to NULL and we must lookup again.
252 */
253 if (!dst_vma) {
254 err = -ENOENT;
255 dst_vma = find_dst_vma(dst_mm, dst_start, len);
256 if (!dst_vma || !is_vm_hugetlb_page(dst_vma))
257 goto out_unlock;
258
259 err = -EINVAL;
260 if (vma_hpagesize != vma_kernel_pagesize(dst_vma))
261 goto out_unlock;
262
263 vm_shared = dst_vma->vm_flags & VM_SHARED;
264 }
265
266 /*
267 * If not shared, ensure the dst_vma has a anon_vma.
268 */
269 err = -ENOMEM;
270 if (!vm_shared) {
271 if (unlikely(anon_vma_prepare(dst_vma)))
272 goto out_unlock;
273 }
274
275 while (src_addr < src_start + len) {
276 BUG_ON(dst_addr >= dst_start + len);
277
278 /*
279 * Serialize via i_mmap_rwsem and hugetlb_fault_mutex.
280 * i_mmap_rwsem ensures the dst_pte remains valid even
281 * in the case of shared pmds. fault mutex prevents
282 * races with other faulting threads.
283 */
284 mapping = dst_vma->vm_file->f_mapping;
285 i_mmap_lock_read(mapping);
286 idx = linear_page_index(dst_vma, dst_addr);
287 hash = hugetlb_fault_mutex_hash(mapping, idx);
288 mutex_lock(&hugetlb_fault_mutex_table[hash]);
289
290 err = -ENOMEM;
291 dst_pte = huge_pte_alloc(dst_mm, dst_vma, dst_addr, vma_hpagesize);
292 if (!dst_pte) {
293 mutex_unlock(&hugetlb_fault_mutex_table[hash]);
294 i_mmap_unlock_read(mapping);
295 goto out_unlock;
296 }
297
298 if (mode != MCOPY_ATOMIC_CONTINUE &&
299 !huge_pte_none(huge_ptep_get(dst_pte))) {
300 err = -EEXIST;
301 mutex_unlock(&hugetlb_fault_mutex_table[hash]);
302 i_mmap_unlock_read(mapping);
303 goto out_unlock;
304 }
305
306 err = hugetlb_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma,
307 dst_addr, src_addr, mode, &page);
308
309 mutex_unlock(&hugetlb_fault_mutex_table[hash]);
310 i_mmap_unlock_read(mapping);
311 vm_alloc_shared = vm_shared;
312
313 cond_resched();
314
315 if (unlikely(err == -ENOENT)) {
316 mmap_read_unlock(dst_mm);
317 BUG_ON(!page);
318
319 err = copy_huge_page_from_user(page,
320 (const void __user *)src_addr,
321 vma_hpagesize / PAGE_SIZE,
322 true);
323 if (unlikely(err)) {
324 err = -EFAULT;
325 goto out;
326 }
327 mmap_read_lock(dst_mm);
328
329 dst_vma = NULL;
330 goto retry;
331 } else
332 BUG_ON(page);
333
334 if (!err) {
335 dst_addr += vma_hpagesize;
336 src_addr += vma_hpagesize;
337 copied += vma_hpagesize;
338
339 if (fatal_signal_pending(current))
340 err = -EINTR;
341 }
342 if (err)
343 break;
344 }
345
346 out_unlock:
347 mmap_read_unlock(dst_mm);
348 out:
349 if (page) {
350 /*
351 * We encountered an error and are about to free a newly
352 * allocated huge page.
353 *
354 * Reservation handling is very subtle, and is different for
355 * private and shared mappings. See the routine
356 * restore_reserve_on_error for details. Unfortunately, we
357 * can not call restore_reserve_on_error now as it would
358 * require holding mmap_lock.
359 *
360 * If a reservation for the page existed in the reservation
361 * map of a private mapping, the map was modified to indicate
362 * the reservation was consumed when the page was allocated.
363 * We clear the HPageRestoreReserve flag now so that the global
364 * reserve count will not be incremented in free_huge_page.
365 * The reservation map will still indicate the reservation
366 * was consumed and possibly prevent later page allocation.
367 * This is better than leaking a global reservation. If no
368 * reservation existed, it is still safe to clear
369 * HPageRestoreReserve as no adjustments to reservation counts
370 * were made during allocation.
371 *
372 * The reservation map for shared mappings indicates which
373 * pages have reservations. When a huge page is allocated
374 * for an address with a reservation, no change is made to
375 * the reserve map. In this case HPageRestoreReserve will be
376 * set to indicate that the global reservation count should be
377 * incremented when the page is freed. This is the desired
378 * behavior. However, when a huge page is allocated for an
379 * address without a reservation a reservation entry is added
380 * to the reservation map, and HPageRestoreReserve will not be
381 * set. When the page is freed, the global reserve count will
382 * NOT be incremented and it will appear as though we have
383 * leaked reserved page. In this case, set HPageRestoreReserve
384 * so that the global reserve count will be incremented to
385 * match the reservation map entry which was created.
386 *
387 * Note that vm_alloc_shared is based on the flags of the vma
388 * for which the page was originally allocated. dst_vma could
389 * be different or NULL on error.
390 */
391 if (vm_alloc_shared)
392 SetHPageRestoreReserve(page);
393 else
394 ClearHPageRestoreReserve(page);
395 put_page(page);
396 }
397 BUG_ON(copied < 0);
398 BUG_ON(err > 0);
399 BUG_ON(!copied && !err);
400 return copied ? copied : err;
401 }
402 #else /* !CONFIG_HUGETLB_PAGE */
403 /* fail at build time if gcc attempts to use this */
404 extern ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
405 struct vm_area_struct *dst_vma,
406 unsigned long dst_start,
407 unsigned long src_start,
408 unsigned long len,
409 enum mcopy_atomic_mode mode);
410 #endif /* CONFIG_HUGETLB_PAGE */
411
412 static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
413 pmd_t *dst_pmd,
414 struct vm_area_struct *dst_vma,
415 unsigned long dst_addr,
416 unsigned long src_addr,
417 struct page **page,
418 bool zeropage,
419 bool wp_copy)
420 {
421 ssize_t err;
422
423 /*
424 * The normal page fault path for a shmem will invoke the
425 * fault, fill the hole in the file and COW it right away. The
426 * result generates plain anonymous memory. So when we are
427 * asked to fill an hole in a MAP_PRIVATE shmem mapping, we'll
428 * generate anonymous memory directly without actually filling
429 * the hole. For the MAP_PRIVATE case the robustness check
430 * only happens in the pagetable (to verify it's still none)
431 * and not in the radix tree.
432 */
433 if (!(dst_vma->vm_flags & VM_SHARED)) {
434 if (!zeropage)
435 err = mcopy_atomic_pte(dst_mm, dst_pmd, dst_vma,
436 dst_addr, src_addr, page,
437 wp_copy);
438 else
439 err = mfill_zeropage_pte(dst_mm, dst_pmd,
440 dst_vma, dst_addr);
441 } else {
442 VM_WARN_ON_ONCE(wp_copy);
443 if (!zeropage)
444 err = shmem_mcopy_atomic_pte(dst_mm, dst_pmd,
445 dst_vma, dst_addr,
446 src_addr, page);
447 else
448 err = shmem_mfill_zeropage_pte(dst_mm, dst_pmd,
449 dst_vma, dst_addr);
450 }
451
452 return err;
453 }
454
455 static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
456 unsigned long dst_start,
457 unsigned long src_start,
458 unsigned long len,
459 enum mcopy_atomic_mode mcopy_mode,
460 bool *mmap_changing,
461 __u64 mode)
462 {
463 struct vm_area_struct *dst_vma;
464 ssize_t err;
465 pmd_t *dst_pmd;
466 unsigned long src_addr, dst_addr;
467 long copied;
468 struct page *page;
469 bool wp_copy;
470 bool zeropage = (mcopy_mode == MCOPY_ATOMIC_ZEROPAGE);
471
472 /*
473 * Sanitize the command parameters:
474 */
475 BUG_ON(dst_start & ~PAGE_MASK);
476 BUG_ON(len & ~PAGE_MASK);
477
478 /* Does the address range wrap, or is the span zero-sized? */
479 BUG_ON(src_start + len <= src_start);
480 BUG_ON(dst_start + len <= dst_start);
481
482 src_addr = src_start;
483 dst_addr = dst_start;
484 copied = 0;
485 page = NULL;
486 retry:
487 mmap_read_lock(dst_mm);
488
489 /*
490 * If memory mappings are changing because of non-cooperative
491 * operation (e.g. mremap) running in parallel, bail out and
492 * request the user to retry later
493 */
494 err = -EAGAIN;
495 if (mmap_changing && READ_ONCE(*mmap_changing))
496 goto out_unlock;
497
498 /*
499 * Make sure the vma is not shared, that the dst range is
500 * both valid and fully within a single existing vma.
501 */
502 err = -ENOENT;
503 dst_vma = find_dst_vma(dst_mm, dst_start, len);
504 if (!dst_vma)
505 goto out_unlock;
506
507 err = -EINVAL;
508 /*
509 * shmem_zero_setup is invoked in mmap for MAP_ANONYMOUS|MAP_SHARED but
510 * it will overwrite vm_ops, so vma_is_anonymous must return false.
511 */
512 if (WARN_ON_ONCE(vma_is_anonymous(dst_vma) &&
513 dst_vma->vm_flags & VM_SHARED))
514 goto out_unlock;
515
516 /*
517 * validate 'mode' now that we know the dst_vma: don't allow
518 * a wrprotect copy if the userfaultfd didn't register as WP.
519 */
520 wp_copy = mode & UFFDIO_COPY_MODE_WP;
521 if (wp_copy && !(dst_vma->vm_flags & VM_UFFD_WP))
522 goto out_unlock;
523
524 /*
525 * If this is a HUGETLB vma, pass off to appropriate routine
526 */
527 if (is_vm_hugetlb_page(dst_vma))
528 return __mcopy_atomic_hugetlb(dst_mm, dst_vma, dst_start,
529 src_start, len, mcopy_mode);
530
531 if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma))
532 goto out_unlock;
533 if (mcopy_mode == MCOPY_ATOMIC_CONTINUE)
534 goto out_unlock;
535
536 /*
537 * Ensure the dst_vma has a anon_vma or this page
538 * would get a NULL anon_vma when moved in the
539 * dst_vma.
540 */
541 err = -ENOMEM;
542 if (!(dst_vma->vm_flags & VM_SHARED) &&
543 unlikely(anon_vma_prepare(dst_vma)))
544 goto out_unlock;
545
546 while (src_addr < src_start + len) {
547 pmd_t dst_pmdval;
548
549 BUG_ON(dst_addr >= dst_start + len);
550
551 dst_pmd = mm_alloc_pmd(dst_mm, dst_addr);
552 if (unlikely(!dst_pmd)) {
553 err = -ENOMEM;
554 break;
555 }
556
557 dst_pmdval = pmd_read_atomic(dst_pmd);
558 /*
559 * If the dst_pmd is mapped as THP don't
560 * override it and just be strict.
561 */
562 if (unlikely(pmd_trans_huge(dst_pmdval))) {
563 err = -EEXIST;
564 break;
565 }
566 if (unlikely(pmd_none(dst_pmdval)) &&
567 unlikely(__pte_alloc(dst_mm, dst_pmd))) {
568 err = -ENOMEM;
569 break;
570 }
571 /* If an huge pmd materialized from under us fail */
572 if (unlikely(pmd_trans_huge(*dst_pmd))) {
573 err = -EFAULT;
574 break;
575 }
576
577 BUG_ON(pmd_none(*dst_pmd));
578 BUG_ON(pmd_trans_huge(*dst_pmd));
579
580 err = mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
581 src_addr, &page, zeropage, wp_copy);
582 cond_resched();
583
584 if (unlikely(err == -ENOENT)) {
585 void *page_kaddr;
586
587 mmap_read_unlock(dst_mm);
588 BUG_ON(!page);
589
590 page_kaddr = kmap(page);
591 err = copy_from_user(page_kaddr,
592 (const void __user *) src_addr,
593 PAGE_SIZE);
594 kunmap(page);
595 if (unlikely(err)) {
596 err = -EFAULT;
597 goto out;
598 }
599 goto retry;
600 } else
601 BUG_ON(page);
602
603 if (!err) {
604 dst_addr += PAGE_SIZE;
605 src_addr += PAGE_SIZE;
606 copied += PAGE_SIZE;
607
608 if (fatal_signal_pending(current))
609 err = -EINTR;
610 }
611 if (err)
612 break;
613 }
614
615 out_unlock:
616 mmap_read_unlock(dst_mm);
617 out:
618 if (page)
619 put_page(page);
620 BUG_ON(copied < 0);
621 BUG_ON(err > 0);
622 BUG_ON(!copied && !err);
623 return copied ? copied : err;
624 }
625
626 ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
627 unsigned long src_start, unsigned long len,
628 bool *mmap_changing, __u64 mode)
629 {
630 return __mcopy_atomic(dst_mm, dst_start, src_start, len,
631 MCOPY_ATOMIC_NORMAL, mmap_changing, mode);
632 }
633
634 ssize_t mfill_zeropage(struct mm_struct *dst_mm, unsigned long start,
635 unsigned long len, bool *mmap_changing)
636 {
637 return __mcopy_atomic(dst_mm, start, 0, len, MCOPY_ATOMIC_ZEROPAGE,
638 mmap_changing, 0);
639 }
640
641 ssize_t mcopy_continue(struct mm_struct *dst_mm, unsigned long start,
642 unsigned long len, bool *mmap_changing)
643 {
644 return __mcopy_atomic(dst_mm, start, 0, len, MCOPY_ATOMIC_CONTINUE,
645 mmap_changing, 0);
646 }
647
648 int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
649 unsigned long len, bool enable_wp, bool *mmap_changing)
650 {
651 struct vm_area_struct *dst_vma;
652 pgprot_t newprot;
653 int err;
654
655 /*
656 * Sanitize the command parameters:
657 */
658 BUG_ON(start & ~PAGE_MASK);
659 BUG_ON(len & ~PAGE_MASK);
660
661 /* Does the address range wrap, or is the span zero-sized? */
662 BUG_ON(start + len <= start);
663
664 mmap_read_lock(dst_mm);
665
666 /*
667 * If memory mappings are changing because of non-cooperative
668 * operation (e.g. mremap) running in parallel, bail out and
669 * request the user to retry later
670 */
671 err = -EAGAIN;
672 if (mmap_changing && READ_ONCE(*mmap_changing))
673 goto out_unlock;
674
675 err = -ENOENT;
676 dst_vma = find_dst_vma(dst_mm, start, len);
677 /*
678 * Make sure the vma is not shared, that the dst range is
679 * both valid and fully within a single existing vma.
680 */
681 if (!dst_vma || (dst_vma->vm_flags & VM_SHARED))
682 goto out_unlock;
683 if (!userfaultfd_wp(dst_vma))
684 goto out_unlock;
685 if (!vma_is_anonymous(dst_vma))
686 goto out_unlock;
687
688 if (enable_wp)
689 newprot = vm_get_page_prot(dst_vma->vm_flags & ~(VM_WRITE));
690 else
691 newprot = vm_get_page_prot(dst_vma->vm_flags);
692
693 change_protection(dst_vma, start, start + len, newprot,
694 enable_wp ? MM_CP_UFFD_WP : MM_CP_UFFD_WP_RESOLVE);
695
696 err = 0;
697 out_unlock:
698 mmap_read_unlock(dst_mm);
699 return err;
700 }