4 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * demand-loading started 01.12.91 - seems it is high on the list of
9 * things wanted, and it should be easy to implement. - Linus
13 * Ok, demand-loading was easy, shared pages a little bit tricker. Shared
14 * pages started 02.12.91, seems to work. - Linus.
16 * Tested sharing by executing about 30 /bin/sh: under the old kernel it
17 * would have taken more than the 6M I have free, but it worked well as
20 * Also corrected some "invalidate()"s - I wasn't doing enough of them.
24 * Real VM (paging to/from disk) started 18.12.91. Much more work and
25 * thought has to go into this. Oh, well..
26 * 19.12.91 - works, somewhat. Sometimes I get faults, don't know why.
27 * Found it. Everything seems to work now.
28 * 20.12.91 - Ok, making the swap-device changeable like the root.
32 * 05.04.94 - Multi-page memory management added for v1.1.
33 * Idea by Alex Bligh (alex@cconcepts.co.uk)
35 * 16.07.99 - Support of BIGMEM added by Gerhard Wichert, Siemens AG
36 * (Gerhard.Wichert@pdb.siemens.de)
38 * Aug/Sep 2004 Changed to four level page tables (Andi Kleen)
41 #include <linux/kernel_stat.h>
43 #include <linux/hugetlb.h>
44 #include <linux/mman.h>
45 #include <linux/swap.h>
46 #include <linux/highmem.h>
47 #include <linux/pagemap.h>
48 #include <linux/rmap.h>
49 #include <linux/module.h>
50 #include <linux/delayacct.h>
51 #include <linux/init.h>
53 #include <asm/pgalloc.h>
54 #include <asm/uaccess.h>
56 #include <asm/tlbflush.h>
57 #include <asm/pgtable.h>
59 #include <linux/swapops.h>
60 #include <linux/elf.h>
62 #ifndef CONFIG_NEED_MULTIPLE_NODES
63 /* use the per-pgdat data instead for discontigmem - mbligh */
64 unsigned long max_mapnr
;
67 EXPORT_SYMBOL(max_mapnr
);
68 EXPORT_SYMBOL(mem_map
);
71 unsigned long num_physpages
;
73 * A number of key systems in x86 including ioremap() rely on the assumption
74 * that high_memory defines the upper bound on direct map memory, then end
75 * of ZONE_NORMAL. Under CONFIG_DISCONTIG this means that max_low_pfn and
76 * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL
80 unsigned long vmalloc_earlyreserve
;
82 EXPORT_SYMBOL(num_physpages
);
83 EXPORT_SYMBOL(high_memory
);
84 EXPORT_SYMBOL(vmalloc_earlyreserve
);
86 int randomize_va_space __read_mostly
= 1;
88 static int __init
disable_randmaps(char *s
)
90 randomize_va_space
= 0;
93 __setup("norandmaps", disable_randmaps
);
97 * If a p?d_bad entry is found while walking page tables, report
98 * the error, before resetting entry to p?d_none. Usually (but
99 * very seldom) called out from the p?d_none_or_clear_bad macros.
102 void pgd_clear_bad(pgd_t
*pgd
)
108 void pud_clear_bad(pud_t
*pud
)
114 void pmd_clear_bad(pmd_t
*pmd
)
121 * Note: this doesn't free the actual pages themselves. That
122 * has been handled earlier when unmapping all the memory regions.
124 static void free_pte_range(struct mmu_gather
*tlb
, pmd_t
*pmd
)
126 struct page
*page
= pmd_page(*pmd
);
128 pte_lock_deinit(page
);
129 pte_free_tlb(tlb
, page
);
130 dec_zone_page_state(page
, NR_PAGETABLE
);
134 static inline void free_pmd_range(struct mmu_gather
*tlb
, pud_t
*pud
,
135 unsigned long addr
, unsigned long end
,
136 unsigned long floor
, unsigned long ceiling
)
143 pmd
= pmd_offset(pud
, addr
);
145 next
= pmd_addr_end(addr
, end
);
146 if (pmd_none_or_clear_bad(pmd
))
148 free_pte_range(tlb
, pmd
);
149 } while (pmd
++, addr
= next
, addr
!= end
);
159 if (end
- 1 > ceiling
- 1)
162 pmd
= pmd_offset(pud
, start
);
164 pmd_free_tlb(tlb
, pmd
);
167 static inline void free_pud_range(struct mmu_gather
*tlb
, pgd_t
*pgd
,
168 unsigned long addr
, unsigned long end
,
169 unsigned long floor
, unsigned long ceiling
)
176 pud
= pud_offset(pgd
, addr
);
178 next
= pud_addr_end(addr
, end
);
179 if (pud_none_or_clear_bad(pud
))
181 free_pmd_range(tlb
, pud
, addr
, next
, floor
, ceiling
);
182 } while (pud
++, addr
= next
, addr
!= end
);
188 ceiling
&= PGDIR_MASK
;
192 if (end
- 1 > ceiling
- 1)
195 pud
= pud_offset(pgd
, start
);
197 pud_free_tlb(tlb
, pud
);
201 * This function frees user-level page tables of a process.
203 * Must be called with pagetable lock held.
205 void free_pgd_range(struct mmu_gather
**tlb
,
206 unsigned long addr
, unsigned long end
,
207 unsigned long floor
, unsigned long ceiling
)
214 * The next few lines have given us lots of grief...
216 * Why are we testing PMD* at this top level? Because often
217 * there will be no work to do at all, and we'd prefer not to
218 * go all the way down to the bottom just to discover that.
220 * Why all these "- 1"s? Because 0 represents both the bottom
221 * of the address space and the top of it (using -1 for the
222 * top wouldn't help much: the masks would do the wrong thing).
223 * The rule is that addr 0 and floor 0 refer to the bottom of
224 * the address space, but end 0 and ceiling 0 refer to the top
225 * Comparisons need to use "end - 1" and "ceiling - 1" (though
226 * that end 0 case should be mythical).
228 * Wherever addr is brought up or ceiling brought down, we must
229 * be careful to reject "the opposite 0" before it confuses the
230 * subsequent tests. But what about where end is brought down
231 * by PMD_SIZE below? no, end can't go down to 0 there.
233 * Whereas we round start (addr) and ceiling down, by different
234 * masks at different levels, in order to test whether a table
235 * now has no other vmas using it, so can be freed, we don't
236 * bother to round floor or end up - the tests don't need that.
250 if (end
- 1 > ceiling
- 1)
256 pgd
= pgd_offset((*tlb
)->mm
, addr
);
258 next
= pgd_addr_end(addr
, end
);
259 if (pgd_none_or_clear_bad(pgd
))
261 free_pud_range(*tlb
, pgd
, addr
, next
, floor
, ceiling
);
262 } while (pgd
++, addr
= next
, addr
!= end
);
265 flush_tlb_pgtables((*tlb
)->mm
, start
, end
);
268 void free_pgtables(struct mmu_gather
**tlb
, struct vm_area_struct
*vma
,
269 unsigned long floor
, unsigned long ceiling
)
272 struct vm_area_struct
*next
= vma
->vm_next
;
273 unsigned long addr
= vma
->vm_start
;
276 * Hide vma from rmap and vmtruncate before freeing pgtables
278 anon_vma_unlink(vma
);
279 unlink_file_vma(vma
);
281 if (is_vm_hugetlb_page(vma
)) {
282 hugetlb_free_pgd_range(tlb
, addr
, vma
->vm_end
,
283 floor
, next
? next
->vm_start
: ceiling
);
286 * Optimization: gather nearby vmas into one call down
288 while (next
&& next
->vm_start
<= vma
->vm_end
+ PMD_SIZE
289 && !is_vm_hugetlb_page(next
)) {
292 anon_vma_unlink(vma
);
293 unlink_file_vma(vma
);
295 free_pgd_range(tlb
, addr
, vma
->vm_end
,
296 floor
, next
? next
->vm_start
: ceiling
);
302 int __pte_alloc(struct mm_struct
*mm
, pmd_t
*pmd
, unsigned long address
)
304 struct page
*new = pte_alloc_one(mm
, address
);
309 spin_lock(&mm
->page_table_lock
);
310 if (pmd_present(*pmd
)) { /* Another has populated it */
311 pte_lock_deinit(new);
315 inc_zone_page_state(new, NR_PAGETABLE
);
316 pmd_populate(mm
, pmd
, new);
318 spin_unlock(&mm
->page_table_lock
);
322 int __pte_alloc_kernel(pmd_t
*pmd
, unsigned long address
)
324 pte_t
*new = pte_alloc_one_kernel(&init_mm
, address
);
328 spin_lock(&init_mm
.page_table_lock
);
329 if (pmd_present(*pmd
)) /* Another has populated it */
330 pte_free_kernel(new);
332 pmd_populate_kernel(&init_mm
, pmd
, new);
333 spin_unlock(&init_mm
.page_table_lock
);
337 static inline void add_mm_rss(struct mm_struct
*mm
, int file_rss
, int anon_rss
)
340 add_mm_counter(mm
, file_rss
, file_rss
);
342 add_mm_counter(mm
, anon_rss
, anon_rss
);
346 * This function is called to print an error when a bad pte
347 * is found. For example, we might have a PFN-mapped pte in
348 * a region that doesn't allow it.
350 * The calling function must still handle the error.
352 void print_bad_pte(struct vm_area_struct
*vma
, pte_t pte
, unsigned long vaddr
)
354 printk(KERN_ERR
"Bad pte = %08llx, process = %s, "
355 "vm_flags = %lx, vaddr = %lx\n",
356 (long long)pte_val(pte
),
357 (vma
->vm_mm
== current
->mm
? current
->comm
: "???"),
358 vma
->vm_flags
, vaddr
);
362 static inline int is_cow_mapping(unsigned int flags
)
364 return (flags
& (VM_SHARED
| VM_MAYWRITE
)) == VM_MAYWRITE
;
368 * This function gets the "struct page" associated with a pte.
370 * NOTE! Some mappings do not have "struct pages". A raw PFN mapping
371 * will have each page table entry just pointing to a raw page frame
372 * number, and as far as the VM layer is concerned, those do not have
373 * pages associated with them - even if the PFN might point to memory
374 * that otherwise is perfectly fine and has a "struct page".
376 * The way we recognize those mappings is through the rules set up
377 * by "remap_pfn_range()": the vma will have the VM_PFNMAP bit set,
378 * and the vm_pgoff will point to the first PFN mapped: thus every
379 * page that is a raw mapping will always honor the rule
381 * pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT)
383 * and if that isn't true, the page has been COW'ed (in which case it
384 * _does_ have a "struct page" associated with it even if it is in a
387 struct page
*vm_normal_page(struct vm_area_struct
*vma
, unsigned long addr
, pte_t pte
)
389 unsigned long pfn
= pte_pfn(pte
);
391 if (unlikely(vma
->vm_flags
& VM_PFNMAP
)) {
392 unsigned long off
= (addr
- vma
->vm_start
) >> PAGE_SHIFT
;
393 if (pfn
== vma
->vm_pgoff
+ off
)
395 if (!is_cow_mapping(vma
->vm_flags
))
400 * Add some anal sanity checks for now. Eventually,
401 * we should just do "return pfn_to_page(pfn)", but
402 * in the meantime we check that we get a valid pfn,
403 * and that the resulting page looks ok.
405 if (unlikely(!pfn_valid(pfn
))) {
406 print_bad_pte(vma
, pte
, addr
);
411 * NOTE! We still have PageReserved() pages in the page
414 * The PAGE_ZERO() pages and various VDSO mappings can
415 * cause them to exist.
417 return pfn_to_page(pfn
);
421 * copy one vm_area from one task to the other. Assumes the page tables
422 * already present in the new task to be cleared in the whole range
423 * covered by this vma.
427 copy_one_pte(struct mm_struct
*dst_mm
, struct mm_struct
*src_mm
,
428 pte_t
*dst_pte
, pte_t
*src_pte
, struct vm_area_struct
*vma
,
429 unsigned long addr
, int *rss
)
431 unsigned long vm_flags
= vma
->vm_flags
;
432 pte_t pte
= *src_pte
;
435 /* pte contains position in swap or file, so copy. */
436 if (unlikely(!pte_present(pte
))) {
437 if (!pte_file(pte
)) {
438 swp_entry_t entry
= pte_to_swp_entry(pte
);
440 swap_duplicate(entry
);
441 /* make sure dst_mm is on swapoff's mmlist. */
442 if (unlikely(list_empty(&dst_mm
->mmlist
))) {
443 spin_lock(&mmlist_lock
);
444 if (list_empty(&dst_mm
->mmlist
))
445 list_add(&dst_mm
->mmlist
,
447 spin_unlock(&mmlist_lock
);
449 if (is_write_migration_entry(entry
) &&
450 is_cow_mapping(vm_flags
)) {
452 * COW mappings require pages in both parent
453 * and child to be set to read.
455 make_migration_entry_read(&entry
);
456 pte
= swp_entry_to_pte(entry
);
457 set_pte_at(src_mm
, addr
, src_pte
, pte
);
464 * If it's a COW mapping, write protect it both
465 * in the parent and the child
467 if (is_cow_mapping(vm_flags
)) {
468 ptep_set_wrprotect(src_mm
, addr
, src_pte
);
473 * If it's a shared mapping, mark it clean in
476 if (vm_flags
& VM_SHARED
)
477 pte
= pte_mkclean(pte
);
478 pte
= pte_mkold(pte
);
480 page
= vm_normal_page(vma
, addr
, pte
);
484 rss
[!!PageAnon(page
)]++;
488 set_pte_at(dst_mm
, addr
, dst_pte
, pte
);
491 static int copy_pte_range(struct mm_struct
*dst_mm
, struct mm_struct
*src_mm
,
492 pmd_t
*dst_pmd
, pmd_t
*src_pmd
, struct vm_area_struct
*vma
,
493 unsigned long addr
, unsigned long end
)
495 pte_t
*src_pte
, *dst_pte
;
496 spinlock_t
*src_ptl
, *dst_ptl
;
502 dst_pte
= pte_alloc_map_lock(dst_mm
, dst_pmd
, addr
, &dst_ptl
);
505 src_pte
= pte_offset_map_nested(src_pmd
, addr
);
506 src_ptl
= pte_lockptr(src_mm
, src_pmd
);
507 spin_lock_nested(src_ptl
, SINGLE_DEPTH_NESTING
);
511 * We are holding two locks at this point - either of them
512 * could generate latencies in another task on another CPU.
514 if (progress
>= 32) {
516 if (need_resched() ||
517 need_lockbreak(src_ptl
) ||
518 need_lockbreak(dst_ptl
))
521 if (pte_none(*src_pte
)) {
525 copy_one_pte(dst_mm
, src_mm
, dst_pte
, src_pte
, vma
, addr
, rss
);
527 } while (dst_pte
++, src_pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
529 spin_unlock(src_ptl
);
530 pte_unmap_nested(src_pte
- 1);
531 add_mm_rss(dst_mm
, rss
[0], rss
[1]);
532 pte_unmap_unlock(dst_pte
- 1, dst_ptl
);
539 static inline int copy_pmd_range(struct mm_struct
*dst_mm
, struct mm_struct
*src_mm
,
540 pud_t
*dst_pud
, pud_t
*src_pud
, struct vm_area_struct
*vma
,
541 unsigned long addr
, unsigned long end
)
543 pmd_t
*src_pmd
, *dst_pmd
;
546 dst_pmd
= pmd_alloc(dst_mm
, dst_pud
, addr
);
549 src_pmd
= pmd_offset(src_pud
, addr
);
551 next
= pmd_addr_end(addr
, end
);
552 if (pmd_none_or_clear_bad(src_pmd
))
554 if (copy_pte_range(dst_mm
, src_mm
, dst_pmd
, src_pmd
,
557 } while (dst_pmd
++, src_pmd
++, addr
= next
, addr
!= end
);
561 static inline int copy_pud_range(struct mm_struct
*dst_mm
, struct mm_struct
*src_mm
,
562 pgd_t
*dst_pgd
, pgd_t
*src_pgd
, struct vm_area_struct
*vma
,
563 unsigned long addr
, unsigned long end
)
565 pud_t
*src_pud
, *dst_pud
;
568 dst_pud
= pud_alloc(dst_mm
, dst_pgd
, addr
);
571 src_pud
= pud_offset(src_pgd
, addr
);
573 next
= pud_addr_end(addr
, end
);
574 if (pud_none_or_clear_bad(src_pud
))
576 if (copy_pmd_range(dst_mm
, src_mm
, dst_pud
, src_pud
,
579 } while (dst_pud
++, src_pud
++, addr
= next
, addr
!= end
);
583 int copy_page_range(struct mm_struct
*dst_mm
, struct mm_struct
*src_mm
,
584 struct vm_area_struct
*vma
)
586 pgd_t
*src_pgd
, *dst_pgd
;
588 unsigned long addr
= vma
->vm_start
;
589 unsigned long end
= vma
->vm_end
;
592 * Don't copy ptes where a page fault will fill them correctly.
593 * Fork becomes much lighter when there are big shared or private
594 * readonly mappings. The tradeoff is that copy_page_range is more
595 * efficient than faulting.
597 if (!(vma
->vm_flags
& (VM_HUGETLB
|VM_NONLINEAR
|VM_PFNMAP
|VM_INSERTPAGE
))) {
602 if (is_vm_hugetlb_page(vma
))
603 return copy_hugetlb_page_range(dst_mm
, src_mm
, vma
);
605 dst_pgd
= pgd_offset(dst_mm
, addr
);
606 src_pgd
= pgd_offset(src_mm
, addr
);
608 next
= pgd_addr_end(addr
, end
);
609 if (pgd_none_or_clear_bad(src_pgd
))
611 if (copy_pud_range(dst_mm
, src_mm
, dst_pgd
, src_pgd
,
614 } while (dst_pgd
++, src_pgd
++, addr
= next
, addr
!= end
);
618 static unsigned long zap_pte_range(struct mmu_gather
*tlb
,
619 struct vm_area_struct
*vma
, pmd_t
*pmd
,
620 unsigned long addr
, unsigned long end
,
621 long *zap_work
, struct zap_details
*details
)
623 struct mm_struct
*mm
= tlb
->mm
;
629 pte
= pte_offset_map_lock(mm
, pmd
, addr
, &ptl
);
632 if (pte_none(ptent
)) {
637 (*zap_work
) -= PAGE_SIZE
;
639 if (pte_present(ptent
)) {
642 page
= vm_normal_page(vma
, addr
, ptent
);
643 if (unlikely(details
) && page
) {
645 * unmap_shared_mapping_pages() wants to
646 * invalidate cache without truncating:
647 * unmap shared but keep private pages.
649 if (details
->check_mapping
&&
650 details
->check_mapping
!= page
->mapping
)
653 * Each page->index must be checked when
654 * invalidating or truncating nonlinear.
656 if (details
->nonlinear_vma
&&
657 (page
->index
< details
->first_index
||
658 page
->index
> details
->last_index
))
661 ptent
= ptep_get_and_clear_full(mm
, addr
, pte
,
663 tlb_remove_tlb_entry(tlb
, pte
, addr
);
666 if (unlikely(details
) && details
->nonlinear_vma
667 && linear_page_index(details
->nonlinear_vma
,
668 addr
) != page
->index
)
669 set_pte_at(mm
, addr
, pte
,
670 pgoff_to_pte(page
->index
));
674 if (pte_dirty(ptent
))
675 set_page_dirty(page
);
676 if (pte_young(ptent
))
677 mark_page_accessed(page
);
680 page_remove_rmap(page
);
681 tlb_remove_page(tlb
, page
);
685 * If details->check_mapping, we leave swap entries;
686 * if details->nonlinear_vma, we leave file entries.
688 if (unlikely(details
))
690 if (!pte_file(ptent
))
691 free_swap_and_cache(pte_to_swp_entry(ptent
));
692 pte_clear_full(mm
, addr
, pte
, tlb
->fullmm
);
693 } while (pte
++, addr
+= PAGE_SIZE
, (addr
!= end
&& *zap_work
> 0));
695 add_mm_rss(mm
, file_rss
, anon_rss
);
696 pte_unmap_unlock(pte
- 1, ptl
);
701 static inline unsigned long zap_pmd_range(struct mmu_gather
*tlb
,
702 struct vm_area_struct
*vma
, pud_t
*pud
,
703 unsigned long addr
, unsigned long end
,
704 long *zap_work
, struct zap_details
*details
)
709 pmd
= pmd_offset(pud
, addr
);
711 next
= pmd_addr_end(addr
, end
);
712 if (pmd_none_or_clear_bad(pmd
)) {
716 next
= zap_pte_range(tlb
, vma
, pmd
, addr
, next
,
718 } while (pmd
++, addr
= next
, (addr
!= end
&& *zap_work
> 0));
723 static inline unsigned long zap_pud_range(struct mmu_gather
*tlb
,
724 struct vm_area_struct
*vma
, pgd_t
*pgd
,
725 unsigned long addr
, unsigned long end
,
726 long *zap_work
, struct zap_details
*details
)
731 pud
= pud_offset(pgd
, addr
);
733 next
= pud_addr_end(addr
, end
);
734 if (pud_none_or_clear_bad(pud
)) {
738 next
= zap_pmd_range(tlb
, vma
, pud
, addr
, next
,
740 } while (pud
++, addr
= next
, (addr
!= end
&& *zap_work
> 0));
745 static unsigned long unmap_page_range(struct mmu_gather
*tlb
,
746 struct vm_area_struct
*vma
,
747 unsigned long addr
, unsigned long end
,
748 long *zap_work
, struct zap_details
*details
)
753 if (details
&& !details
->check_mapping
&& !details
->nonlinear_vma
)
757 tlb_start_vma(tlb
, vma
);
758 pgd
= pgd_offset(vma
->vm_mm
, addr
);
760 next
= pgd_addr_end(addr
, end
);
761 if (pgd_none_or_clear_bad(pgd
)) {
765 next
= zap_pud_range(tlb
, vma
, pgd
, addr
, next
,
767 } while (pgd
++, addr
= next
, (addr
!= end
&& *zap_work
> 0));
768 tlb_end_vma(tlb
, vma
);
773 #ifdef CONFIG_PREEMPT
774 # define ZAP_BLOCK_SIZE (8 * PAGE_SIZE)
776 /* No preempt: go for improved straight-line efficiency */
777 # define ZAP_BLOCK_SIZE (1024 * PAGE_SIZE)
781 * unmap_vmas - unmap a range of memory covered by a list of vma's
782 * @tlbp: address of the caller's struct mmu_gather
783 * @vma: the starting vma
784 * @start_addr: virtual address at which to start unmapping
785 * @end_addr: virtual address at which to end unmapping
786 * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
787 * @details: details of nonlinear truncation or shared cache invalidation
789 * Returns the end address of the unmapping (restart addr if interrupted).
791 * Unmap all pages in the vma list.
793 * We aim to not hold locks for too long (for scheduling latency reasons).
794 * So zap pages in ZAP_BLOCK_SIZE bytecounts. This means we need to
795 * return the ending mmu_gather to the caller.
797 * Only addresses between `start' and `end' will be unmapped.
799 * The VMA list must be sorted in ascending virtual address order.
801 * unmap_vmas() assumes that the caller will flush the whole unmapped address
802 * range after unmap_vmas() returns. So the only responsibility here is to
803 * ensure that any thus-far unmapped pages are flushed before unmap_vmas()
804 * drops the lock and schedules.
806 unsigned long unmap_vmas(struct mmu_gather
**tlbp
,
807 struct vm_area_struct
*vma
, unsigned long start_addr
,
808 unsigned long end_addr
, unsigned long *nr_accounted
,
809 struct zap_details
*details
)
811 long zap_work
= ZAP_BLOCK_SIZE
;
812 unsigned long tlb_start
= 0; /* For tlb_finish_mmu */
813 int tlb_start_valid
= 0;
814 unsigned long start
= start_addr
;
815 spinlock_t
*i_mmap_lock
= details
? details
->i_mmap_lock
: NULL
;
816 int fullmm
= (*tlbp
)->fullmm
;
818 for ( ; vma
&& vma
->vm_start
< end_addr
; vma
= vma
->vm_next
) {
821 start
= max(vma
->vm_start
, start_addr
);
822 if (start
>= vma
->vm_end
)
824 end
= min(vma
->vm_end
, end_addr
);
825 if (end
<= vma
->vm_start
)
828 if (vma
->vm_flags
& VM_ACCOUNT
)
829 *nr_accounted
+= (end
- start
) >> PAGE_SHIFT
;
831 while (start
!= end
) {
832 if (!tlb_start_valid
) {
837 if (unlikely(is_vm_hugetlb_page(vma
))) {
838 unmap_hugepage_range(vma
, start
, end
);
839 zap_work
-= (end
- start
) /
840 (HPAGE_SIZE
/ PAGE_SIZE
);
843 start
= unmap_page_range(*tlbp
, vma
,
844 start
, end
, &zap_work
, details
);
847 BUG_ON(start
!= end
);
851 tlb_finish_mmu(*tlbp
, tlb_start
, start
);
853 if (need_resched() ||
854 (i_mmap_lock
&& need_lockbreak(i_mmap_lock
))) {
862 *tlbp
= tlb_gather_mmu(vma
->vm_mm
, fullmm
);
864 zap_work
= ZAP_BLOCK_SIZE
;
868 return start
; /* which is now the end (or restart) address */
872 * zap_page_range - remove user pages in a given range
873 * @vma: vm_area_struct holding the applicable pages
874 * @address: starting address of pages to zap
875 * @size: number of bytes to zap
876 * @details: details of nonlinear truncation or shared cache invalidation
878 unsigned long zap_page_range(struct vm_area_struct
*vma
, unsigned long address
,
879 unsigned long size
, struct zap_details
*details
)
881 struct mm_struct
*mm
= vma
->vm_mm
;
882 struct mmu_gather
*tlb
;
883 unsigned long end
= address
+ size
;
884 unsigned long nr_accounted
= 0;
887 tlb
= tlb_gather_mmu(mm
, 0);
888 update_hiwater_rss(mm
);
889 end
= unmap_vmas(&tlb
, vma
, address
, end
, &nr_accounted
, details
);
891 tlb_finish_mmu(tlb
, address
, end
);
896 * Do a quick page-table lookup for a single page.
898 struct page
*follow_page(struct vm_area_struct
*vma
, unsigned long address
,
907 struct mm_struct
*mm
= vma
->vm_mm
;
909 page
= follow_huge_addr(mm
, address
, flags
& FOLL_WRITE
);
911 BUG_ON(flags
& FOLL_GET
);
916 pgd
= pgd_offset(mm
, address
);
917 if (pgd_none(*pgd
) || unlikely(pgd_bad(*pgd
)))
920 pud
= pud_offset(pgd
, address
);
921 if (pud_none(*pud
) || unlikely(pud_bad(*pud
)))
924 pmd
= pmd_offset(pud
, address
);
925 if (pmd_none(*pmd
) || unlikely(pmd_bad(*pmd
)))
928 if (pmd_huge(*pmd
)) {
929 BUG_ON(flags
& FOLL_GET
);
930 page
= follow_huge_pmd(mm
, address
, pmd
, flags
& FOLL_WRITE
);
934 ptep
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
939 if (!pte_present(pte
))
941 if ((flags
& FOLL_WRITE
) && !pte_write(pte
))
943 page
= vm_normal_page(vma
, address
, pte
);
947 if (flags
& FOLL_GET
)
949 if (flags
& FOLL_TOUCH
) {
950 if ((flags
& FOLL_WRITE
) &&
951 !pte_dirty(pte
) && !PageDirty(page
))
952 set_page_dirty(page
);
953 mark_page_accessed(page
);
956 pte_unmap_unlock(ptep
, ptl
);
962 * When core dumping an enormous anonymous area that nobody
963 * has touched so far, we don't want to allocate page tables.
965 if (flags
& FOLL_ANON
) {
966 page
= ZERO_PAGE(address
);
967 if (flags
& FOLL_GET
)
969 BUG_ON(flags
& FOLL_WRITE
);
974 int get_user_pages(struct task_struct
*tsk
, struct mm_struct
*mm
,
975 unsigned long start
, int len
, int write
, int force
,
976 struct page
**pages
, struct vm_area_struct
**vmas
)
979 unsigned int vm_flags
;
982 * Require read or write permissions.
983 * If 'force' is set, we only require the "MAY" flags.
985 vm_flags
= write
? (VM_WRITE
| VM_MAYWRITE
) : (VM_READ
| VM_MAYREAD
);
986 vm_flags
&= force
? (VM_MAYREAD
| VM_MAYWRITE
) : (VM_READ
| VM_WRITE
);
990 struct vm_area_struct
*vma
;
991 unsigned int foll_flags
;
993 vma
= find_extend_vma(mm
, start
);
994 if (!vma
&& in_gate_area(tsk
, start
)) {
995 unsigned long pg
= start
& PAGE_MASK
;
996 struct vm_area_struct
*gate_vma
= get_gate_vma(tsk
);
1001 if (write
) /* user gate pages are read-only */
1002 return i
? : -EFAULT
;
1004 pgd
= pgd_offset_k(pg
);
1006 pgd
= pgd_offset_gate(mm
, pg
);
1007 BUG_ON(pgd_none(*pgd
));
1008 pud
= pud_offset(pgd
, pg
);
1009 BUG_ON(pud_none(*pud
));
1010 pmd
= pmd_offset(pud
, pg
);
1012 return i
? : -EFAULT
;
1013 pte
= pte_offset_map(pmd
, pg
);
1014 if (pte_none(*pte
)) {
1016 return i
? : -EFAULT
;
1019 struct page
*page
= vm_normal_page(gate_vma
, start
, *pte
);
1033 if (!vma
|| (vma
->vm_flags
& (VM_IO
| VM_PFNMAP
))
1034 || !(vm_flags
& vma
->vm_flags
))
1035 return i
? : -EFAULT
;
1037 if (is_vm_hugetlb_page(vma
)) {
1038 i
= follow_hugetlb_page(mm
, vma
, pages
, vmas
,
1043 foll_flags
= FOLL_TOUCH
;
1045 foll_flags
|= FOLL_GET
;
1046 if (!write
&& !(vma
->vm_flags
& VM_LOCKED
) &&
1047 (!vma
->vm_ops
|| !vma
->vm_ops
->nopage
))
1048 foll_flags
|= FOLL_ANON
;
1054 foll_flags
|= FOLL_WRITE
;
1057 while (!(page
= follow_page(vma
, start
, foll_flags
))) {
1059 ret
= __handle_mm_fault(mm
, vma
, start
,
1060 foll_flags
& FOLL_WRITE
);
1062 * The VM_FAULT_WRITE bit tells us that do_wp_page has
1063 * broken COW when necessary, even if maybe_mkwrite
1064 * decided not to set pte_write. We can thus safely do
1065 * subsequent page lookups as if they were reads.
1067 if (ret
& VM_FAULT_WRITE
)
1068 foll_flags
&= ~FOLL_WRITE
;
1070 switch (ret
& ~VM_FAULT_WRITE
) {
1071 case VM_FAULT_MINOR
:
1074 case VM_FAULT_MAJOR
:
1077 case VM_FAULT_SIGBUS
:
1078 return i
? i
: -EFAULT
;
1080 return i
? i
: -ENOMEM
;
1088 flush_anon_page(page
, start
);
1089 flush_dcache_page(page
);
1096 } while (len
&& start
< vma
->vm_end
);
1100 EXPORT_SYMBOL(get_user_pages
);
1102 static int zeromap_pte_range(struct mm_struct
*mm
, pmd_t
*pmd
,
1103 unsigned long addr
, unsigned long end
, pgprot_t prot
)
1109 pte
= pte_alloc_map_lock(mm
, pmd
, addr
, &ptl
);
1113 struct page
*page
= ZERO_PAGE(addr
);
1114 pte_t zero_pte
= pte_wrprotect(mk_pte(page
, prot
));
1116 if (unlikely(!pte_none(*pte
))) {
1121 page_cache_get(page
);
1122 page_add_file_rmap(page
);
1123 inc_mm_counter(mm
, file_rss
);
1124 set_pte_at(mm
, addr
, pte
, zero_pte
);
1125 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
1126 pte_unmap_unlock(pte
- 1, ptl
);
1130 static inline int zeromap_pmd_range(struct mm_struct
*mm
, pud_t
*pud
,
1131 unsigned long addr
, unsigned long end
, pgprot_t prot
)
1137 pmd
= pmd_alloc(mm
, pud
, addr
);
1141 next
= pmd_addr_end(addr
, end
);
1142 err
= zeromap_pte_range(mm
, pmd
, addr
, next
, prot
);
1145 } while (pmd
++, addr
= next
, addr
!= end
);
1149 static inline int zeromap_pud_range(struct mm_struct
*mm
, pgd_t
*pgd
,
1150 unsigned long addr
, unsigned long end
, pgprot_t prot
)
1156 pud
= pud_alloc(mm
, pgd
, addr
);
1160 next
= pud_addr_end(addr
, end
);
1161 err
= zeromap_pmd_range(mm
, pud
, addr
, next
, prot
);
1164 } while (pud
++, addr
= next
, addr
!= end
);
1168 int zeromap_page_range(struct vm_area_struct
*vma
,
1169 unsigned long addr
, unsigned long size
, pgprot_t prot
)
1173 unsigned long end
= addr
+ size
;
1174 struct mm_struct
*mm
= vma
->vm_mm
;
1177 BUG_ON(addr
>= end
);
1178 pgd
= pgd_offset(mm
, addr
);
1179 flush_cache_range(vma
, addr
, end
);
1181 next
= pgd_addr_end(addr
, end
);
1182 err
= zeromap_pud_range(mm
, pgd
, addr
, next
, prot
);
1185 } while (pgd
++, addr
= next
, addr
!= end
);
1189 pte_t
* fastcall
get_locked_pte(struct mm_struct
*mm
, unsigned long addr
, spinlock_t
**ptl
)
1191 pgd_t
* pgd
= pgd_offset(mm
, addr
);
1192 pud_t
* pud
= pud_alloc(mm
, pgd
, addr
);
1194 pmd_t
* pmd
= pmd_alloc(mm
, pud
, addr
);
1196 return pte_alloc_map_lock(mm
, pmd
, addr
, ptl
);
1202 * This is the old fallback for page remapping.
1204 * For historical reasons, it only allows reserved pages. Only
1205 * old drivers should use this, and they needed to mark their
1206 * pages reserved for the old functions anyway.
1208 static int insert_page(struct mm_struct
*mm
, unsigned long addr
, struct page
*page
, pgprot_t prot
)
1218 flush_dcache_page(page
);
1219 pte
= get_locked_pte(mm
, addr
, &ptl
);
1223 if (!pte_none(*pte
))
1226 /* Ok, finally just insert the thing.. */
1228 inc_mm_counter(mm
, file_rss
);
1229 page_add_file_rmap(page
);
1230 set_pte_at(mm
, addr
, pte
, mk_pte(page
, prot
));
1234 pte_unmap_unlock(pte
, ptl
);
1240 * This allows drivers to insert individual pages they've allocated
1243 * The page has to be a nice clean _individual_ kernel allocation.
1244 * If you allocate a compound page, you need to have marked it as
1245 * such (__GFP_COMP), or manually just split the page up yourself
1246 * (see split_page()).
1248 * NOTE! Traditionally this was done with "remap_pfn_range()" which
1249 * took an arbitrary page protection parameter. This doesn't allow
1250 * that. Your vma protection will have to be set up correctly, which
1251 * means that if you want a shared writable mapping, you'd better
1252 * ask for a shared writable mapping!
1254 * The page does not need to be reserved.
1256 int vm_insert_page(struct vm_area_struct
*vma
, unsigned long addr
, struct page
*page
)
1258 if (addr
< vma
->vm_start
|| addr
>= vma
->vm_end
)
1260 if (!page_count(page
))
1262 vma
->vm_flags
|= VM_INSERTPAGE
;
1263 return insert_page(vma
->vm_mm
, addr
, page
, vma
->vm_page_prot
);
1265 EXPORT_SYMBOL(vm_insert_page
);
1268 * maps a range of physical memory into the requested pages. the old
1269 * mappings are removed. any references to nonexistent pages results
1270 * in null mappings (currently treated as "copy-on-access")
1272 static int remap_pte_range(struct mm_struct
*mm
, pmd_t
*pmd
,
1273 unsigned long addr
, unsigned long end
,
1274 unsigned long pfn
, pgprot_t prot
)
1279 pte
= pte_alloc_map_lock(mm
, pmd
, addr
, &ptl
);
1283 BUG_ON(!pte_none(*pte
));
1284 set_pte_at(mm
, addr
, pte
, pfn_pte(pfn
, prot
));
1286 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
1287 pte_unmap_unlock(pte
- 1, ptl
);
1291 static inline int remap_pmd_range(struct mm_struct
*mm
, pud_t
*pud
,
1292 unsigned long addr
, unsigned long end
,
1293 unsigned long pfn
, pgprot_t prot
)
1298 pfn
-= addr
>> PAGE_SHIFT
;
1299 pmd
= pmd_alloc(mm
, pud
, addr
);
1303 next
= pmd_addr_end(addr
, end
);
1304 if (remap_pte_range(mm
, pmd
, addr
, next
,
1305 pfn
+ (addr
>> PAGE_SHIFT
), prot
))
1307 } while (pmd
++, addr
= next
, addr
!= end
);
1311 static inline int remap_pud_range(struct mm_struct
*mm
, pgd_t
*pgd
,
1312 unsigned long addr
, unsigned long end
,
1313 unsigned long pfn
, pgprot_t prot
)
1318 pfn
-= addr
>> PAGE_SHIFT
;
1319 pud
= pud_alloc(mm
, pgd
, addr
);
1323 next
= pud_addr_end(addr
, end
);
1324 if (remap_pmd_range(mm
, pud
, addr
, next
,
1325 pfn
+ (addr
>> PAGE_SHIFT
), prot
))
1327 } while (pud
++, addr
= next
, addr
!= end
);
1331 /* Note: this is only safe if the mm semaphore is held when called. */
1332 int remap_pfn_range(struct vm_area_struct
*vma
, unsigned long addr
,
1333 unsigned long pfn
, unsigned long size
, pgprot_t prot
)
1337 unsigned long end
= addr
+ PAGE_ALIGN(size
);
1338 struct mm_struct
*mm
= vma
->vm_mm
;
1342 * Physically remapped pages are special. Tell the
1343 * rest of the world about it:
1344 * VM_IO tells people not to look at these pages
1345 * (accesses can have side effects).
1346 * VM_RESERVED is specified all over the place, because
1347 * in 2.4 it kept swapout's vma scan off this vma; but
1348 * in 2.6 the LRU scan won't even find its pages, so this
1349 * flag means no more than count its pages in reserved_vm,
1350 * and omit it from core dump, even when VM_IO turned off.
1351 * VM_PFNMAP tells the core MM that the base pages are just
1352 * raw PFN mappings, and do not have a "struct page" associated
1355 * There's a horrible special case to handle copy-on-write
1356 * behaviour that some programs depend on. We mark the "original"
1357 * un-COW'ed pages by matching them up with "vma->vm_pgoff".
1359 if (is_cow_mapping(vma
->vm_flags
)) {
1360 if (addr
!= vma
->vm_start
|| end
!= vma
->vm_end
)
1362 vma
->vm_pgoff
= pfn
;
1365 vma
->vm_flags
|= VM_IO
| VM_RESERVED
| VM_PFNMAP
;
1367 BUG_ON(addr
>= end
);
1368 pfn
-= addr
>> PAGE_SHIFT
;
1369 pgd
= pgd_offset(mm
, addr
);
1370 flush_cache_range(vma
, addr
, end
);
1372 next
= pgd_addr_end(addr
, end
);
1373 err
= remap_pud_range(mm
, pgd
, addr
, next
,
1374 pfn
+ (addr
>> PAGE_SHIFT
), prot
);
1377 } while (pgd
++, addr
= next
, addr
!= end
);
1380 EXPORT_SYMBOL(remap_pfn_range
);
1383 * handle_pte_fault chooses page fault handler according to an entry
1384 * which was read non-atomically. Before making any commitment, on
1385 * those architectures or configurations (e.g. i386 with PAE) which
1386 * might give a mix of unmatched parts, do_swap_page and do_file_page
1387 * must check under lock before unmapping the pte and proceeding
1388 * (but do_wp_page is only called after already making such a check;
1389 * and do_anonymous_page and do_no_page can safely check later on).
1391 static inline int pte_unmap_same(struct mm_struct
*mm
, pmd_t
*pmd
,
1392 pte_t
*page_table
, pte_t orig_pte
)
1395 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
1396 if (sizeof(pte_t
) > sizeof(unsigned long)) {
1397 spinlock_t
*ptl
= pte_lockptr(mm
, pmd
);
1399 same
= pte_same(*page_table
, orig_pte
);
1403 pte_unmap(page_table
);
1408 * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when
1409 * servicing faults for write access. In the normal case, do always want
1410 * pte_mkwrite. But get_user_pages can cause write faults for mappings
1411 * that do not have writing enabled, when used by access_process_vm.
1413 static inline pte_t
maybe_mkwrite(pte_t pte
, struct vm_area_struct
*vma
)
1415 if (likely(vma
->vm_flags
& VM_WRITE
))
1416 pte
= pte_mkwrite(pte
);
1420 static inline void cow_user_page(struct page
*dst
, struct page
*src
, unsigned long va
)
1423 * If the source page was a PFN mapping, we don't have
1424 * a "struct page" for it. We do a best-effort copy by
1425 * just copying from the original user address. If that
1426 * fails, we just zero-fill it. Live with it.
1428 if (unlikely(!src
)) {
1429 void *kaddr
= kmap_atomic(dst
, KM_USER0
);
1430 void __user
*uaddr
= (void __user
*)(va
& PAGE_MASK
);
1433 * This really shouldn't fail, because the page is there
1434 * in the page tables. But it might just be unreadable,
1435 * in which case we just give up and fill the result with
1438 if (__copy_from_user_inatomic(kaddr
, uaddr
, PAGE_SIZE
))
1439 memset(kaddr
, 0, PAGE_SIZE
);
1440 kunmap_atomic(kaddr
, KM_USER0
);
1444 copy_user_highpage(dst
, src
, va
);
1448 * This routine handles present pages, when users try to write
1449 * to a shared page. It is done by copying the page to a new address
1450 * and decrementing the shared-page counter for the old page.
1452 * Note that this routine assumes that the protection checks have been
1453 * done by the caller (the low-level page fault routine in most cases).
1454 * Thus we can safely just mark it writable once we've done any necessary
1457 * We also mark the page dirty at this point even though the page will
1458 * change only once the write actually happens. This avoids a few races,
1459 * and potentially makes it more efficient.
1461 * We enter with non-exclusive mmap_sem (to exclude vma changes,
1462 * but allow concurrent faults), with pte both mapped and locked.
1463 * We return with mmap_sem still held, but pte unmapped and unlocked.
1465 static int do_wp_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
1466 unsigned long address
, pte_t
*page_table
, pmd_t
*pmd
,
1467 spinlock_t
*ptl
, pte_t orig_pte
)
1469 struct page
*old_page
, *new_page
;
1471 int reuse
, ret
= VM_FAULT_MINOR
;
1473 old_page
= vm_normal_page(vma
, address
, orig_pte
);
1477 if (unlikely((vma
->vm_flags
& (VM_SHARED
|VM_WRITE
)) ==
1478 (VM_SHARED
|VM_WRITE
))) {
1479 if (vma
->vm_ops
&& vma
->vm_ops
->page_mkwrite
) {
1481 * Notify the address space that the page is about to
1482 * become writable so that it can prohibit this or wait
1483 * for the page to get into an appropriate state.
1485 * We do this without the lock held, so that it can
1486 * sleep if it needs to.
1488 page_cache_get(old_page
);
1489 pte_unmap_unlock(page_table
, ptl
);
1491 if (vma
->vm_ops
->page_mkwrite(vma
, old_page
) < 0)
1492 goto unwritable_page
;
1494 page_cache_release(old_page
);
1497 * Since we dropped the lock we need to revalidate
1498 * the PTE as someone else may have changed it. If
1499 * they did, we just return, as we can count on the
1500 * MMU to tell us if they didn't also make it writable.
1502 page_table
= pte_offset_map_lock(mm
, pmd
, address
,
1504 if (!pte_same(*page_table
, orig_pte
))
1509 } else if (PageAnon(old_page
) && !TestSetPageLocked(old_page
)) {
1510 reuse
= can_share_swap_page(old_page
);
1511 unlock_page(old_page
);
1517 flush_cache_page(vma
, address
, pte_pfn(orig_pte
));
1518 entry
= pte_mkyoung(orig_pte
);
1519 entry
= maybe_mkwrite(pte_mkdirty(entry
), vma
);
1520 ptep_set_access_flags(vma
, address
, page_table
, entry
, 1);
1521 update_mmu_cache(vma
, address
, entry
);
1522 lazy_mmu_prot_update(entry
);
1523 ret
|= VM_FAULT_WRITE
;
1528 * Ok, we need to copy. Oh, well..
1530 page_cache_get(old_page
);
1532 pte_unmap_unlock(page_table
, ptl
);
1534 if (unlikely(anon_vma_prepare(vma
)))
1536 if (old_page
== ZERO_PAGE(address
)) {
1537 new_page
= alloc_zeroed_user_highpage(vma
, address
);
1541 new_page
= alloc_page_vma(GFP_HIGHUSER
, vma
, address
);
1544 cow_user_page(new_page
, old_page
, address
);
1548 * Re-check the pte - we dropped the lock
1550 page_table
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
1551 if (likely(pte_same(*page_table
, orig_pte
))) {
1553 page_remove_rmap(old_page
);
1554 if (!PageAnon(old_page
)) {
1555 dec_mm_counter(mm
, file_rss
);
1556 inc_mm_counter(mm
, anon_rss
);
1559 inc_mm_counter(mm
, anon_rss
);
1560 flush_cache_page(vma
, address
, pte_pfn(orig_pte
));
1561 entry
= mk_pte(new_page
, vma
->vm_page_prot
);
1562 entry
= maybe_mkwrite(pte_mkdirty(entry
), vma
);
1563 lazy_mmu_prot_update(entry
);
1565 * Clear the pte entry and flush it first, before updating the
1566 * pte with the new entry. This will avoid a race condition
1567 * seen in the presence of one thread doing SMC and another
1570 ptep_clear_flush(vma
, address
, page_table
);
1571 set_pte_at(mm
, address
, page_table
, entry
);
1572 update_mmu_cache(vma
, address
, entry
);
1573 lru_cache_add_active(new_page
);
1574 page_add_new_anon_rmap(new_page
, vma
, address
);
1576 /* Free the old page.. */
1577 new_page
= old_page
;
1578 ret
|= VM_FAULT_WRITE
;
1581 page_cache_release(new_page
);
1583 page_cache_release(old_page
);
1585 pte_unmap_unlock(page_table
, ptl
);
1589 page_cache_release(old_page
);
1590 return VM_FAULT_OOM
;
1593 page_cache_release(old_page
);
1594 return VM_FAULT_SIGBUS
;
1598 * Helper functions for unmap_mapping_range().
1600 * __ Notes on dropping i_mmap_lock to reduce latency while unmapping __
1602 * We have to restart searching the prio_tree whenever we drop the lock,
1603 * since the iterator is only valid while the lock is held, and anyway
1604 * a later vma might be split and reinserted earlier while lock dropped.
1606 * The list of nonlinear vmas could be handled more efficiently, using
1607 * a placeholder, but handle it in the same way until a need is shown.
1608 * It is important to search the prio_tree before nonlinear list: a vma
1609 * may become nonlinear and be shifted from prio_tree to nonlinear list
1610 * while the lock is dropped; but never shifted from list to prio_tree.
1612 * In order to make forward progress despite restarting the search,
1613 * vm_truncate_count is used to mark a vma as now dealt with, so we can
1614 * quickly skip it next time around. Since the prio_tree search only
1615 * shows us those vmas affected by unmapping the range in question, we
1616 * can't efficiently keep all vmas in step with mapping->truncate_count:
1617 * so instead reset them all whenever it wraps back to 0 (then go to 1).
1618 * mapping->truncate_count and vma->vm_truncate_count are protected by
1621 * In order to make forward progress despite repeatedly restarting some
1622 * large vma, note the restart_addr from unmap_vmas when it breaks out:
1623 * and restart from that address when we reach that vma again. It might
1624 * have been split or merged, shrunk or extended, but never shifted: so
1625 * restart_addr remains valid so long as it remains in the vma's range.
1626 * unmap_mapping_range forces truncate_count to leap over page-aligned
1627 * values so we can save vma's restart_addr in its truncate_count field.
1629 #define is_restart_addr(truncate_count) (!((truncate_count) & ~PAGE_MASK))
1631 static void reset_vma_truncate_counts(struct address_space
*mapping
)
1633 struct vm_area_struct
*vma
;
1634 struct prio_tree_iter iter
;
1636 vma_prio_tree_foreach(vma
, &iter
, &mapping
->i_mmap
, 0, ULONG_MAX
)
1637 vma
->vm_truncate_count
= 0;
1638 list_for_each_entry(vma
, &mapping
->i_mmap_nonlinear
, shared
.vm_set
.list
)
1639 vma
->vm_truncate_count
= 0;
1642 static int unmap_mapping_range_vma(struct vm_area_struct
*vma
,
1643 unsigned long start_addr
, unsigned long end_addr
,
1644 struct zap_details
*details
)
1646 unsigned long restart_addr
;
1650 restart_addr
= vma
->vm_truncate_count
;
1651 if (is_restart_addr(restart_addr
) && start_addr
< restart_addr
) {
1652 start_addr
= restart_addr
;
1653 if (start_addr
>= end_addr
) {
1654 /* Top of vma has been split off since last time */
1655 vma
->vm_truncate_count
= details
->truncate_count
;
1660 restart_addr
= zap_page_range(vma
, start_addr
,
1661 end_addr
- start_addr
, details
);
1662 need_break
= need_resched() ||
1663 need_lockbreak(details
->i_mmap_lock
);
1665 if (restart_addr
>= end_addr
) {
1666 /* We have now completed this vma: mark it so */
1667 vma
->vm_truncate_count
= details
->truncate_count
;
1671 /* Note restart_addr in vma's truncate_count field */
1672 vma
->vm_truncate_count
= restart_addr
;
1677 spin_unlock(details
->i_mmap_lock
);
1679 spin_lock(details
->i_mmap_lock
);
1683 static inline void unmap_mapping_range_tree(struct prio_tree_root
*root
,
1684 struct zap_details
*details
)
1686 struct vm_area_struct
*vma
;
1687 struct prio_tree_iter iter
;
1688 pgoff_t vba
, vea
, zba
, zea
;
1691 vma_prio_tree_foreach(vma
, &iter
, root
,
1692 details
->first_index
, details
->last_index
) {
1693 /* Skip quickly over those we have already dealt with */
1694 if (vma
->vm_truncate_count
== details
->truncate_count
)
1697 vba
= vma
->vm_pgoff
;
1698 vea
= vba
+ ((vma
->vm_end
- vma
->vm_start
) >> PAGE_SHIFT
) - 1;
1699 /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */
1700 zba
= details
->first_index
;
1703 zea
= details
->last_index
;
1707 if (unmap_mapping_range_vma(vma
,
1708 ((zba
- vba
) << PAGE_SHIFT
) + vma
->vm_start
,
1709 ((zea
- vba
+ 1) << PAGE_SHIFT
) + vma
->vm_start
,
1715 static inline void unmap_mapping_range_list(struct list_head
*head
,
1716 struct zap_details
*details
)
1718 struct vm_area_struct
*vma
;
1721 * In nonlinear VMAs there is no correspondence between virtual address
1722 * offset and file offset. So we must perform an exhaustive search
1723 * across *all* the pages in each nonlinear VMA, not just the pages
1724 * whose virtual address lies outside the file truncation point.
1727 list_for_each_entry(vma
, head
, shared
.vm_set
.list
) {
1728 /* Skip quickly over those we have already dealt with */
1729 if (vma
->vm_truncate_count
== details
->truncate_count
)
1731 details
->nonlinear_vma
= vma
;
1732 if (unmap_mapping_range_vma(vma
, vma
->vm_start
,
1733 vma
->vm_end
, details
) < 0)
1739 * unmap_mapping_range - unmap the portion of all mmaps
1740 * in the specified address_space corresponding to the specified
1741 * page range in the underlying file.
1742 * @mapping: the address space containing mmaps to be unmapped.
1743 * @holebegin: byte in first page to unmap, relative to the start of
1744 * the underlying file. This will be rounded down to a PAGE_SIZE
1745 * boundary. Note that this is different from vmtruncate(), which
1746 * must keep the partial page. In contrast, we must get rid of
1748 * @holelen: size of prospective hole in bytes. This will be rounded
1749 * up to a PAGE_SIZE boundary. A holelen of zero truncates to the
1751 * @even_cows: 1 when truncating a file, unmap even private COWed pages;
1752 * but 0 when invalidating pagecache, don't throw away private data.
1754 void unmap_mapping_range(struct address_space
*mapping
,
1755 loff_t
const holebegin
, loff_t
const holelen
, int even_cows
)
1757 struct zap_details details
;
1758 pgoff_t hba
= holebegin
>> PAGE_SHIFT
;
1759 pgoff_t hlen
= (holelen
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1761 /* Check for overflow. */
1762 if (sizeof(holelen
) > sizeof(hlen
)) {
1764 (holebegin
+ holelen
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1765 if (holeend
& ~(long long)ULONG_MAX
)
1766 hlen
= ULONG_MAX
- hba
+ 1;
1769 details
.check_mapping
= even_cows
? NULL
: mapping
;
1770 details
.nonlinear_vma
= NULL
;
1771 details
.first_index
= hba
;
1772 details
.last_index
= hba
+ hlen
- 1;
1773 if (details
.last_index
< details
.first_index
)
1774 details
.last_index
= ULONG_MAX
;
1775 details
.i_mmap_lock
= &mapping
->i_mmap_lock
;
1777 spin_lock(&mapping
->i_mmap_lock
);
1779 /* serialize i_size write against truncate_count write */
1781 /* Protect against page faults, and endless unmapping loops */
1782 mapping
->truncate_count
++;
1784 * For archs where spin_lock has inclusive semantics like ia64
1785 * this smp_mb() will prevent to read pagetable contents
1786 * before the truncate_count increment is visible to
1790 if (unlikely(is_restart_addr(mapping
->truncate_count
))) {
1791 if (mapping
->truncate_count
== 0)
1792 reset_vma_truncate_counts(mapping
);
1793 mapping
->truncate_count
++;
1795 details
.truncate_count
= mapping
->truncate_count
;
1797 if (unlikely(!prio_tree_empty(&mapping
->i_mmap
)))
1798 unmap_mapping_range_tree(&mapping
->i_mmap
, &details
);
1799 if (unlikely(!list_empty(&mapping
->i_mmap_nonlinear
)))
1800 unmap_mapping_range_list(&mapping
->i_mmap_nonlinear
, &details
);
1801 spin_unlock(&mapping
->i_mmap_lock
);
1803 EXPORT_SYMBOL(unmap_mapping_range
);
1806 * Handle all mappings that got truncated by a "truncate()"
1809 * NOTE! We have to be ready to update the memory sharing
1810 * between the file and the memory map for a potential last
1811 * incomplete page. Ugly, but necessary.
1813 int vmtruncate(struct inode
* inode
, loff_t offset
)
1815 struct address_space
*mapping
= inode
->i_mapping
;
1816 unsigned long limit
;
1818 if (inode
->i_size
< offset
)
1821 * truncation of in-use swapfiles is disallowed - it would cause
1822 * subsequent swapout to scribble on the now-freed blocks.
1824 if (IS_SWAPFILE(inode
))
1826 i_size_write(inode
, offset
);
1827 unmap_mapping_range(mapping
, offset
+ PAGE_SIZE
- 1, 0, 1);
1828 truncate_inode_pages(mapping
, offset
);
1832 limit
= current
->signal
->rlim
[RLIMIT_FSIZE
].rlim_cur
;
1833 if (limit
!= RLIM_INFINITY
&& offset
> limit
)
1835 if (offset
> inode
->i_sb
->s_maxbytes
)
1837 i_size_write(inode
, offset
);
1840 if (inode
->i_op
&& inode
->i_op
->truncate
)
1841 inode
->i_op
->truncate(inode
);
1844 send_sig(SIGXFSZ
, current
, 0);
1850 EXPORT_SYMBOL(vmtruncate
);
1852 int vmtruncate_range(struct inode
*inode
, loff_t offset
, loff_t end
)
1854 struct address_space
*mapping
= inode
->i_mapping
;
1857 * If the underlying filesystem is not going to provide
1858 * a way to truncate a range of blocks (punch a hole) -
1859 * we should return failure right now.
1861 if (!inode
->i_op
|| !inode
->i_op
->truncate_range
)
1864 mutex_lock(&inode
->i_mutex
);
1865 down_write(&inode
->i_alloc_sem
);
1866 unmap_mapping_range(mapping
, offset
, (end
- offset
), 1);
1867 truncate_inode_pages_range(mapping
, offset
, end
);
1868 inode
->i_op
->truncate_range(inode
, offset
, end
);
1869 up_write(&inode
->i_alloc_sem
);
1870 mutex_unlock(&inode
->i_mutex
);
1874 EXPORT_UNUSED_SYMBOL(vmtruncate_range
); /* June 2006 */
1877 * Primitive swap readahead code. We simply read an aligned block of
1878 * (1 << page_cluster) entries in the swap area. This method is chosen
1879 * because it doesn't cost us any seek time. We also make sure to queue
1880 * the 'original' request together with the readahead ones...
1882 * This has been extended to use the NUMA policies from the mm triggering
1885 * Caller must hold down_read on the vma->vm_mm if vma is not NULL.
1887 void swapin_readahead(swp_entry_t entry
, unsigned long addr
,struct vm_area_struct
*vma
)
1890 struct vm_area_struct
*next_vma
= vma
? vma
->vm_next
: NULL
;
1893 struct page
*new_page
;
1894 unsigned long offset
;
1897 * Get the number of handles we should do readahead io to.
1899 num
= valid_swaphandles(entry
, &offset
);
1900 for (i
= 0; i
< num
; offset
++, i
++) {
1901 /* Ok, do the async read-ahead now */
1902 new_page
= read_swap_cache_async(swp_entry(swp_type(entry
),
1903 offset
), vma
, addr
);
1906 page_cache_release(new_page
);
1909 * Find the next applicable VMA for the NUMA policy.
1915 if (addr
>= vma
->vm_end
) {
1917 next_vma
= vma
? vma
->vm_next
: NULL
;
1919 if (vma
&& addr
< vma
->vm_start
)
1922 if (next_vma
&& addr
>= next_vma
->vm_start
) {
1924 next_vma
= vma
->vm_next
;
1929 lru_add_drain(); /* Push any new pages onto the LRU now */
1933 * We enter with non-exclusive mmap_sem (to exclude vma changes,
1934 * but allow concurrent faults), and pte mapped but not yet locked.
1935 * We return with mmap_sem still held, but pte unmapped and unlocked.
1937 static int do_swap_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
1938 unsigned long address
, pte_t
*page_table
, pmd_t
*pmd
,
1939 int write_access
, pte_t orig_pte
)
1945 int ret
= VM_FAULT_MINOR
;
1947 if (!pte_unmap_same(mm
, pmd
, page_table
, orig_pte
))
1950 entry
= pte_to_swp_entry(orig_pte
);
1951 if (is_migration_entry(entry
)) {
1952 migration_entry_wait(mm
, pmd
, address
);
1955 delayacct_set_flag(DELAYACCT_PF_SWAPIN
);
1956 page
= lookup_swap_cache(entry
);
1958 swapin_readahead(entry
, address
, vma
);
1959 page
= read_swap_cache_async(entry
, vma
, address
);
1962 * Back out if somebody else faulted in this pte
1963 * while we released the pte lock.
1965 page_table
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
1966 if (likely(pte_same(*page_table
, orig_pte
)))
1968 delayacct_clear_flag(DELAYACCT_PF_SWAPIN
);
1972 /* Had to read the page from swap area: Major fault */
1973 ret
= VM_FAULT_MAJOR
;
1974 count_vm_event(PGMAJFAULT
);
1978 delayacct_clear_flag(DELAYACCT_PF_SWAPIN
);
1979 mark_page_accessed(page
);
1983 * Back out if somebody else already faulted in this pte.
1985 page_table
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
1986 if (unlikely(!pte_same(*page_table
, orig_pte
)))
1989 if (unlikely(!PageUptodate(page
))) {
1990 ret
= VM_FAULT_SIGBUS
;
1994 /* The page isn't present yet, go ahead with the fault. */
1996 inc_mm_counter(mm
, anon_rss
);
1997 pte
= mk_pte(page
, vma
->vm_page_prot
);
1998 if (write_access
&& can_share_swap_page(page
)) {
1999 pte
= maybe_mkwrite(pte_mkdirty(pte
), vma
);
2003 flush_icache_page(vma
, page
);
2004 set_pte_at(mm
, address
, page_table
, pte
);
2005 page_add_anon_rmap(page
, vma
, address
);
2009 remove_exclusive_swap_page(page
);
2013 if (do_wp_page(mm
, vma
, address
,
2014 page_table
, pmd
, ptl
, pte
) == VM_FAULT_OOM
)
2019 /* No need to invalidate - it was non-present before */
2020 update_mmu_cache(vma
, address
, pte
);
2021 lazy_mmu_prot_update(pte
);
2023 pte_unmap_unlock(page_table
, ptl
);
2027 pte_unmap_unlock(page_table
, ptl
);
2029 page_cache_release(page
);
2034 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2035 * but allow concurrent faults), and pte mapped but not yet locked.
2036 * We return with mmap_sem still held, but pte unmapped and unlocked.
2038 static int do_anonymous_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
2039 unsigned long address
, pte_t
*page_table
, pmd_t
*pmd
,
2047 /* Allocate our own private page. */
2048 pte_unmap(page_table
);
2050 if (unlikely(anon_vma_prepare(vma
)))
2052 page
= alloc_zeroed_user_highpage(vma
, address
);
2056 entry
= mk_pte(page
, vma
->vm_page_prot
);
2057 entry
= maybe_mkwrite(pte_mkdirty(entry
), vma
);
2059 page_table
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
2060 if (!pte_none(*page_table
))
2062 inc_mm_counter(mm
, anon_rss
);
2063 lru_cache_add_active(page
);
2064 page_add_new_anon_rmap(page
, vma
, address
);
2066 /* Map the ZERO_PAGE - vm_page_prot is readonly */
2067 page
= ZERO_PAGE(address
);
2068 page_cache_get(page
);
2069 entry
= mk_pte(page
, vma
->vm_page_prot
);
2071 ptl
= pte_lockptr(mm
, pmd
);
2073 if (!pte_none(*page_table
))
2075 inc_mm_counter(mm
, file_rss
);
2076 page_add_file_rmap(page
);
2079 set_pte_at(mm
, address
, page_table
, entry
);
2081 /* No need to invalidate - it was non-present before */
2082 update_mmu_cache(vma
, address
, entry
);
2083 lazy_mmu_prot_update(entry
);
2085 pte_unmap_unlock(page_table
, ptl
);
2086 return VM_FAULT_MINOR
;
2088 page_cache_release(page
);
2091 return VM_FAULT_OOM
;
2095 * do_no_page() tries to create a new page mapping. It aggressively
2096 * tries to share with existing pages, but makes a separate copy if
2097 * the "write_access" parameter is true in order to avoid the next
2100 * As this is called only for pages that do not currently exist, we
2101 * do not need to flush old virtual caches or the TLB.
2103 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2104 * but allow concurrent faults), and pte mapped but not yet locked.
2105 * We return with mmap_sem still held, but pte unmapped and unlocked.
2107 static int do_no_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
2108 unsigned long address
, pte_t
*page_table
, pmd_t
*pmd
,
2112 struct page
*new_page
;
2113 struct address_space
*mapping
= NULL
;
2115 unsigned int sequence
= 0;
2116 int ret
= VM_FAULT_MINOR
;
2119 pte_unmap(page_table
);
2120 BUG_ON(vma
->vm_flags
& VM_PFNMAP
);
2123 mapping
= vma
->vm_file
->f_mapping
;
2124 sequence
= mapping
->truncate_count
;
2125 smp_rmb(); /* serializes i_size against truncate_count */
2128 new_page
= vma
->vm_ops
->nopage(vma
, address
& PAGE_MASK
, &ret
);
2130 * No smp_rmb is needed here as long as there's a full
2131 * spin_lock/unlock sequence inside the ->nopage callback
2132 * (for the pagecache lookup) that acts as an implicit
2133 * smp_mb() and prevents the i_size read to happen
2134 * after the next truncate_count read.
2137 /* no page was available -- either SIGBUS or OOM */
2138 if (new_page
== NOPAGE_SIGBUS
)
2139 return VM_FAULT_SIGBUS
;
2140 if (new_page
== NOPAGE_OOM
)
2141 return VM_FAULT_OOM
;
2144 * Should we do an early C-O-W break?
2147 if (!(vma
->vm_flags
& VM_SHARED
)) {
2150 if (unlikely(anon_vma_prepare(vma
)))
2152 page
= alloc_page_vma(GFP_HIGHUSER
, vma
, address
);
2155 copy_user_highpage(page
, new_page
, address
);
2156 page_cache_release(new_page
);
2161 /* if the page will be shareable, see if the backing
2162 * address space wants to know that the page is about
2163 * to become writable */
2164 if (vma
->vm_ops
->page_mkwrite
&&
2165 vma
->vm_ops
->page_mkwrite(vma
, new_page
) < 0
2167 page_cache_release(new_page
);
2168 return VM_FAULT_SIGBUS
;
2173 page_table
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
2175 * For a file-backed vma, someone could have truncated or otherwise
2176 * invalidated this page. If unmap_mapping_range got called,
2177 * retry getting the page.
2179 if (mapping
&& unlikely(sequence
!= mapping
->truncate_count
)) {
2180 pte_unmap_unlock(page_table
, ptl
);
2181 page_cache_release(new_page
);
2183 sequence
= mapping
->truncate_count
;
2189 * This silly early PAGE_DIRTY setting removes a race
2190 * due to the bad i386 page protection. But it's valid
2191 * for other architectures too.
2193 * Note that if write_access is true, we either now have
2194 * an exclusive copy of the page, or this is a shared mapping,
2195 * so we can make it writable and dirty to avoid having to
2196 * handle that later.
2198 /* Only go through if we didn't race with anybody else... */
2199 if (pte_none(*page_table
)) {
2200 flush_icache_page(vma
, new_page
);
2201 entry
= mk_pte(new_page
, vma
->vm_page_prot
);
2203 entry
= maybe_mkwrite(pte_mkdirty(entry
), vma
);
2204 set_pte_at(mm
, address
, page_table
, entry
);
2206 inc_mm_counter(mm
, anon_rss
);
2207 lru_cache_add_active(new_page
);
2208 page_add_new_anon_rmap(new_page
, vma
, address
);
2210 inc_mm_counter(mm
, file_rss
);
2211 page_add_file_rmap(new_page
);
2214 /* One of our sibling threads was faster, back out. */
2215 page_cache_release(new_page
);
2219 /* no need to invalidate: a not-present page shouldn't be cached */
2220 update_mmu_cache(vma
, address
, entry
);
2221 lazy_mmu_prot_update(entry
);
2223 pte_unmap_unlock(page_table
, ptl
);
2226 page_cache_release(new_page
);
2227 return VM_FAULT_OOM
;
2231 * Fault of a previously existing named mapping. Repopulate the pte
2232 * from the encoded file_pte if possible. This enables swappable
2235 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2236 * but allow concurrent faults), and pte mapped but not yet locked.
2237 * We return with mmap_sem still held, but pte unmapped and unlocked.
2239 static int do_file_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
2240 unsigned long address
, pte_t
*page_table
, pmd_t
*pmd
,
2241 int write_access
, pte_t orig_pte
)
2246 if (!pte_unmap_same(mm
, pmd
, page_table
, orig_pte
))
2247 return VM_FAULT_MINOR
;
2249 if (unlikely(!(vma
->vm_flags
& VM_NONLINEAR
))) {
2251 * Page table corrupted: show pte and kill process.
2253 print_bad_pte(vma
, orig_pte
, address
);
2254 return VM_FAULT_OOM
;
2256 /* We can then assume vm->vm_ops && vma->vm_ops->populate */
2258 pgoff
= pte_to_pgoff(orig_pte
);
2259 err
= vma
->vm_ops
->populate(vma
, address
& PAGE_MASK
, PAGE_SIZE
,
2260 vma
->vm_page_prot
, pgoff
, 0);
2262 return VM_FAULT_OOM
;
2264 return VM_FAULT_SIGBUS
;
2265 return VM_FAULT_MAJOR
;
2269 * These routines also need to handle stuff like marking pages dirty
2270 * and/or accessed for architectures that don't do it in hardware (most
2271 * RISC architectures). The early dirtying is also good on the i386.
2273 * There is also a hook called "update_mmu_cache()" that architectures
2274 * with external mmu caches can use to update those (ie the Sparc or
2275 * PowerPC hashed page tables that act as extended TLBs).
2277 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2278 * but allow concurrent faults), and pte mapped but not yet locked.
2279 * We return with mmap_sem still held, but pte unmapped and unlocked.
2281 static inline int handle_pte_fault(struct mm_struct
*mm
,
2282 struct vm_area_struct
*vma
, unsigned long address
,
2283 pte_t
*pte
, pmd_t
*pmd
, int write_access
)
2289 old_entry
= entry
= *pte
;
2290 if (!pte_present(entry
)) {
2291 if (pte_none(entry
)) {
2292 if (!vma
->vm_ops
|| !vma
->vm_ops
->nopage
)
2293 return do_anonymous_page(mm
, vma
, address
,
2294 pte
, pmd
, write_access
);
2295 return do_no_page(mm
, vma
, address
,
2296 pte
, pmd
, write_access
);
2298 if (pte_file(entry
))
2299 return do_file_page(mm
, vma
, address
,
2300 pte
, pmd
, write_access
, entry
);
2301 return do_swap_page(mm
, vma
, address
,
2302 pte
, pmd
, write_access
, entry
);
2305 ptl
= pte_lockptr(mm
, pmd
);
2307 if (unlikely(!pte_same(*pte
, entry
)))
2310 if (!pte_write(entry
))
2311 return do_wp_page(mm
, vma
, address
,
2312 pte
, pmd
, ptl
, entry
);
2313 entry
= pte_mkdirty(entry
);
2315 entry
= pte_mkyoung(entry
);
2316 if (!pte_same(old_entry
, entry
)) {
2317 ptep_set_access_flags(vma
, address
, pte
, entry
, write_access
);
2318 update_mmu_cache(vma
, address
, entry
);
2319 lazy_mmu_prot_update(entry
);
2322 * This is needed only for protection faults but the arch code
2323 * is not yet telling us if this is a protection fault or not.
2324 * This still avoids useless tlb flushes for .text page faults
2328 flush_tlb_page(vma
, address
);
2331 pte_unmap_unlock(pte
, ptl
);
2332 return VM_FAULT_MINOR
;
2336 * By the time we get here, we already hold the mm semaphore
2338 int __handle_mm_fault(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
2339 unsigned long address
, int write_access
)
2346 __set_current_state(TASK_RUNNING
);
2348 count_vm_event(PGFAULT
);
2350 if (unlikely(is_vm_hugetlb_page(vma
)))
2351 return hugetlb_fault(mm
, vma
, address
, write_access
);
2353 pgd
= pgd_offset(mm
, address
);
2354 pud
= pud_alloc(mm
, pgd
, address
);
2356 return VM_FAULT_OOM
;
2357 pmd
= pmd_alloc(mm
, pud
, address
);
2359 return VM_FAULT_OOM
;
2360 pte
= pte_alloc_map(mm
, pmd
, address
);
2362 return VM_FAULT_OOM
;
2364 return handle_pte_fault(mm
, vma
, address
, pte
, pmd
, write_access
);
2367 EXPORT_SYMBOL_GPL(__handle_mm_fault
);
2369 #ifndef __PAGETABLE_PUD_FOLDED
2371 * Allocate page upper directory.
2372 * We've already handled the fast-path in-line.
2374 int __pud_alloc(struct mm_struct
*mm
, pgd_t
*pgd
, unsigned long address
)
2376 pud_t
*new = pud_alloc_one(mm
, address
);
2380 spin_lock(&mm
->page_table_lock
);
2381 if (pgd_present(*pgd
)) /* Another has populated it */
2384 pgd_populate(mm
, pgd
, new);
2385 spin_unlock(&mm
->page_table_lock
);
2389 /* Workaround for gcc 2.96 */
2390 int __pud_alloc(struct mm_struct
*mm
, pgd_t
*pgd
, unsigned long address
)
2394 #endif /* __PAGETABLE_PUD_FOLDED */
2396 #ifndef __PAGETABLE_PMD_FOLDED
2398 * Allocate page middle directory.
2399 * We've already handled the fast-path in-line.
2401 int __pmd_alloc(struct mm_struct
*mm
, pud_t
*pud
, unsigned long address
)
2403 pmd_t
*new = pmd_alloc_one(mm
, address
);
2407 spin_lock(&mm
->page_table_lock
);
2408 #ifndef __ARCH_HAS_4LEVEL_HACK
2409 if (pud_present(*pud
)) /* Another has populated it */
2412 pud_populate(mm
, pud
, new);
2414 if (pgd_present(*pud
)) /* Another has populated it */
2417 pgd_populate(mm
, pud
, new);
2418 #endif /* __ARCH_HAS_4LEVEL_HACK */
2419 spin_unlock(&mm
->page_table_lock
);
2423 /* Workaround for gcc 2.96 */
2424 int __pmd_alloc(struct mm_struct
*mm
, pud_t
*pud
, unsigned long address
)
2428 #endif /* __PAGETABLE_PMD_FOLDED */
2430 int make_pages_present(unsigned long addr
, unsigned long end
)
2432 int ret
, len
, write
;
2433 struct vm_area_struct
* vma
;
2435 vma
= find_vma(current
->mm
, addr
);
2438 write
= (vma
->vm_flags
& VM_WRITE
) != 0;
2439 BUG_ON(addr
>= end
);
2440 BUG_ON(end
> vma
->vm_end
);
2441 len
= (end
+PAGE_SIZE
-1)/PAGE_SIZE
-addr
/PAGE_SIZE
;
2442 ret
= get_user_pages(current
, current
->mm
, addr
,
2443 len
, write
, 0, NULL
, NULL
);
2446 return ret
== len
? 0 : -1;
2450 * Map a vmalloc()-space virtual address to the physical page.
2452 struct page
* vmalloc_to_page(void * vmalloc_addr
)
2454 unsigned long addr
= (unsigned long) vmalloc_addr
;
2455 struct page
*page
= NULL
;
2456 pgd_t
*pgd
= pgd_offset_k(addr
);
2461 if (!pgd_none(*pgd
)) {
2462 pud
= pud_offset(pgd
, addr
);
2463 if (!pud_none(*pud
)) {
2464 pmd
= pmd_offset(pud
, addr
);
2465 if (!pmd_none(*pmd
)) {
2466 ptep
= pte_offset_map(pmd
, addr
);
2468 if (pte_present(pte
))
2469 page
= pte_page(pte
);
2477 EXPORT_SYMBOL(vmalloc_to_page
);
2480 * Map a vmalloc()-space virtual address to the physical page frame number.
2482 unsigned long vmalloc_to_pfn(void * vmalloc_addr
)
2484 return page_to_pfn(vmalloc_to_page(vmalloc_addr
));
2487 EXPORT_SYMBOL(vmalloc_to_pfn
);
2489 #if !defined(__HAVE_ARCH_GATE_AREA)
2491 #if defined(AT_SYSINFO_EHDR)
2492 static struct vm_area_struct gate_vma
;
2494 static int __init
gate_vma_init(void)
2496 gate_vma
.vm_mm
= NULL
;
2497 gate_vma
.vm_start
= FIXADDR_USER_START
;
2498 gate_vma
.vm_end
= FIXADDR_USER_END
;
2499 gate_vma
.vm_page_prot
= PAGE_READONLY
;
2500 gate_vma
.vm_flags
= 0;
2503 __initcall(gate_vma_init
);
2506 struct vm_area_struct
*get_gate_vma(struct task_struct
*tsk
)
2508 #ifdef AT_SYSINFO_EHDR
2515 int in_gate_area_no_task(unsigned long addr
)
2517 #ifdef AT_SYSINFO_EHDR
2518 if ((addr
>= FIXADDR_USER_START
) && (addr
< FIXADDR_USER_END
))
2524 #endif /* __HAVE_ARCH_GATE_AREA */