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/init.h>
52 #include <asm/pgalloc.h>
53 #include <asm/uaccess.h>
55 #include <asm/tlbflush.h>
56 #include <asm/pgtable.h>
58 #include <linux/swapops.h>
59 #include <linux/elf.h>
61 #ifndef CONFIG_NEED_MULTIPLE_NODES
62 /* use the per-pgdat data instead for discontigmem - mbligh */
63 unsigned long max_mapnr
;
66 EXPORT_SYMBOL(max_mapnr
);
67 EXPORT_SYMBOL(mem_map
);
70 unsigned long num_physpages
;
72 * A number of key systems in x86 including ioremap() rely on the assumption
73 * that high_memory defines the upper bound on direct map memory, then end
74 * of ZONE_NORMAL. Under CONFIG_DISCONTIG this means that max_low_pfn and
75 * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL
79 unsigned long vmalloc_earlyreserve
;
81 EXPORT_SYMBOL(num_physpages
);
82 EXPORT_SYMBOL(high_memory
);
83 EXPORT_SYMBOL(vmalloc_earlyreserve
);
86 * If a p?d_bad entry is found while walking page tables, report
87 * the error, before resetting entry to p?d_none. Usually (but
88 * very seldom) called out from the p?d_none_or_clear_bad macros.
91 void pgd_clear_bad(pgd_t
*pgd
)
97 void pud_clear_bad(pud_t
*pud
)
103 void pmd_clear_bad(pmd_t
*pmd
)
110 * Note: this doesn't free the actual pages themselves. That
111 * has been handled earlier when unmapping all the memory regions.
113 static void free_pte_range(struct mmu_gather
*tlb
, pmd_t
*pmd
)
115 struct page
*page
= pmd_page(*pmd
);
117 pte_lock_deinit(page
);
118 pte_free_tlb(tlb
, page
);
119 dec_page_state(nr_page_table_pages
);
123 static inline void free_pmd_range(struct mmu_gather
*tlb
, pud_t
*pud
,
124 unsigned long addr
, unsigned long end
,
125 unsigned long floor
, unsigned long ceiling
)
132 pmd
= pmd_offset(pud
, addr
);
134 next
= pmd_addr_end(addr
, end
);
135 if (pmd_none_or_clear_bad(pmd
))
137 free_pte_range(tlb
, pmd
);
138 } while (pmd
++, addr
= next
, addr
!= end
);
148 if (end
- 1 > ceiling
- 1)
151 pmd
= pmd_offset(pud
, start
);
153 pmd_free_tlb(tlb
, pmd
);
156 static inline void free_pud_range(struct mmu_gather
*tlb
, pgd_t
*pgd
,
157 unsigned long addr
, unsigned long end
,
158 unsigned long floor
, unsigned long ceiling
)
165 pud
= pud_offset(pgd
, addr
);
167 next
= pud_addr_end(addr
, end
);
168 if (pud_none_or_clear_bad(pud
))
170 free_pmd_range(tlb
, pud
, addr
, next
, floor
, ceiling
);
171 } while (pud
++, addr
= next
, addr
!= end
);
177 ceiling
&= PGDIR_MASK
;
181 if (end
- 1 > ceiling
- 1)
184 pud
= pud_offset(pgd
, start
);
186 pud_free_tlb(tlb
, pud
);
190 * This function frees user-level page tables of a process.
192 * Must be called with pagetable lock held.
194 void free_pgd_range(struct mmu_gather
**tlb
,
195 unsigned long addr
, unsigned long end
,
196 unsigned long floor
, unsigned long ceiling
)
203 * The next few lines have given us lots of grief...
205 * Why are we testing PMD* at this top level? Because often
206 * there will be no work to do at all, and we'd prefer not to
207 * go all the way down to the bottom just to discover that.
209 * Why all these "- 1"s? Because 0 represents both the bottom
210 * of the address space and the top of it (using -1 for the
211 * top wouldn't help much: the masks would do the wrong thing).
212 * The rule is that addr 0 and floor 0 refer to the bottom of
213 * the address space, but end 0 and ceiling 0 refer to the top
214 * Comparisons need to use "end - 1" and "ceiling - 1" (though
215 * that end 0 case should be mythical).
217 * Wherever addr is brought up or ceiling brought down, we must
218 * be careful to reject "the opposite 0" before it confuses the
219 * subsequent tests. But what about where end is brought down
220 * by PMD_SIZE below? no, end can't go down to 0 there.
222 * Whereas we round start (addr) and ceiling down, by different
223 * masks at different levels, in order to test whether a table
224 * now has no other vmas using it, so can be freed, we don't
225 * bother to round floor or end up - the tests don't need that.
239 if (end
- 1 > ceiling
- 1)
245 pgd
= pgd_offset((*tlb
)->mm
, addr
);
247 next
= pgd_addr_end(addr
, end
);
248 if (pgd_none_or_clear_bad(pgd
))
250 free_pud_range(*tlb
, pgd
, addr
, next
, floor
, ceiling
);
251 } while (pgd
++, addr
= next
, addr
!= end
);
254 flush_tlb_pgtables((*tlb
)->mm
, start
, end
);
257 void free_pgtables(struct mmu_gather
**tlb
, struct vm_area_struct
*vma
,
258 unsigned long floor
, unsigned long ceiling
)
261 struct vm_area_struct
*next
= vma
->vm_next
;
262 unsigned long addr
= vma
->vm_start
;
265 * Hide vma from rmap and vmtruncate before freeing pgtables
267 anon_vma_unlink(vma
);
268 unlink_file_vma(vma
);
270 if (is_hugepage_only_range(vma
->vm_mm
, addr
, HPAGE_SIZE
)) {
271 hugetlb_free_pgd_range(tlb
, addr
, vma
->vm_end
,
272 floor
, next
? next
->vm_start
: ceiling
);
275 * Optimization: gather nearby vmas into one call down
277 while (next
&& next
->vm_start
<= vma
->vm_end
+ PMD_SIZE
278 && !is_hugepage_only_range(vma
->vm_mm
, next
->vm_start
,
282 anon_vma_unlink(vma
);
283 unlink_file_vma(vma
);
285 free_pgd_range(tlb
, addr
, vma
->vm_end
,
286 floor
, next
? next
->vm_start
: ceiling
);
292 int __pte_alloc(struct mm_struct
*mm
, pmd_t
*pmd
, unsigned long address
)
294 struct page
*new = pte_alloc_one(mm
, address
);
299 spin_lock(&mm
->page_table_lock
);
300 if (pmd_present(*pmd
)) { /* Another has populated it */
301 pte_lock_deinit(new);
305 inc_page_state(nr_page_table_pages
);
306 pmd_populate(mm
, pmd
, new);
308 spin_unlock(&mm
->page_table_lock
);
312 int __pte_alloc_kernel(pmd_t
*pmd
, unsigned long address
)
314 pte_t
*new = pte_alloc_one_kernel(&init_mm
, address
);
318 spin_lock(&init_mm
.page_table_lock
);
319 if (pmd_present(*pmd
)) /* Another has populated it */
320 pte_free_kernel(new);
322 pmd_populate_kernel(&init_mm
, pmd
, new);
323 spin_unlock(&init_mm
.page_table_lock
);
327 static inline void add_mm_rss(struct mm_struct
*mm
, int file_rss
, int anon_rss
)
330 add_mm_counter(mm
, file_rss
, file_rss
);
332 add_mm_counter(mm
, anon_rss
, anon_rss
);
336 * This function is called to print an error when a bad pte
337 * is found. For example, we might have a PFN-mapped pte in
338 * a region that doesn't allow it.
340 * The calling function must still handle the error.
342 void print_bad_pte(struct vm_area_struct
*vma
, pte_t pte
, unsigned long vaddr
)
344 printk(KERN_ERR
"Bad pte = %08llx, process = %s, "
345 "vm_flags = %lx, vaddr = %lx\n",
346 (long long)pte_val(pte
),
347 (vma
->vm_mm
== current
->mm
? current
->comm
: "???"),
348 vma
->vm_flags
, vaddr
);
353 * This function gets the "struct page" associated with a pte.
355 * NOTE! Some mappings do not have "struct pages". A raw PFN mapping
356 * will have each page table entry just pointing to a raw page frame
357 * number, and as far as the VM layer is concerned, those do not have
358 * pages associated with them - even if the PFN might point to memory
359 * that otherwise is perfectly fine and has a "struct page".
361 * The way we recognize those mappings is through the rules set up
362 * by "remap_pfn_range()": the vma will have the VM_PFNMAP bit set,
363 * and the vm_pgoff will point to the first PFN mapped: thus every
364 * page that is a raw mapping will always honor the rule
366 * pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT)
368 * and if that isn't true, the page has been COW'ed (in which case it
369 * _does_ have a "struct page" associated with it even if it is in a
372 struct page
*vm_normal_page(struct vm_area_struct
*vma
, unsigned long addr
, pte_t pte
)
374 unsigned long pfn
= pte_pfn(pte
);
376 if (vma
->vm_flags
& VM_PFNMAP
) {
377 unsigned long off
= (addr
- vma
->vm_start
) >> PAGE_SHIFT
;
378 if (pfn
== vma
->vm_pgoff
+ off
)
380 if (vma
->vm_flags
& VM_SHARED
)
385 * Add some anal sanity checks for now. Eventually,
386 * we should just do "return pfn_to_page(pfn)", but
387 * in the meantime we check that we get a valid pfn,
388 * and that the resulting page looks ok.
390 * Remove this test eventually!
392 if (unlikely(!pfn_valid(pfn
))) {
393 print_bad_pte(vma
, pte
, addr
);
398 * NOTE! We still have PageReserved() pages in the page
401 * The PAGE_ZERO() pages and various VDSO mappings can
402 * cause them to exist.
404 return pfn_to_page(pfn
);
408 * copy one vm_area from one task to the other. Assumes the page tables
409 * already present in the new task to be cleared in the whole range
410 * covered by this vma.
414 copy_one_pte(struct mm_struct
*dst_mm
, struct mm_struct
*src_mm
,
415 pte_t
*dst_pte
, pte_t
*src_pte
, struct vm_area_struct
*vma
,
416 unsigned long addr
, int *rss
)
418 unsigned long vm_flags
= vma
->vm_flags
;
419 pte_t pte
= *src_pte
;
422 /* pte contains position in swap or file, so copy. */
423 if (unlikely(!pte_present(pte
))) {
424 if (!pte_file(pte
)) {
425 swap_duplicate(pte_to_swp_entry(pte
));
426 /* make sure dst_mm is on swapoff's mmlist. */
427 if (unlikely(list_empty(&dst_mm
->mmlist
))) {
428 spin_lock(&mmlist_lock
);
429 if (list_empty(&dst_mm
->mmlist
))
430 list_add(&dst_mm
->mmlist
,
432 spin_unlock(&mmlist_lock
);
439 * If it's a COW mapping, write protect it both
440 * in the parent and the child
442 if ((vm_flags
& (VM_SHARED
| VM_MAYWRITE
)) == VM_MAYWRITE
) {
443 ptep_set_wrprotect(src_mm
, addr
, src_pte
);
448 * If it's a shared mapping, mark it clean in
451 if (vm_flags
& VM_SHARED
)
452 pte
= pte_mkclean(pte
);
453 pte
= pte_mkold(pte
);
455 page
= vm_normal_page(vma
, addr
, pte
);
459 rss
[!!PageAnon(page
)]++;
463 set_pte_at(dst_mm
, addr
, dst_pte
, pte
);
466 static int copy_pte_range(struct mm_struct
*dst_mm
, struct mm_struct
*src_mm
,
467 pmd_t
*dst_pmd
, pmd_t
*src_pmd
, struct vm_area_struct
*vma
,
468 unsigned long addr
, unsigned long end
)
470 pte_t
*src_pte
, *dst_pte
;
471 spinlock_t
*src_ptl
, *dst_ptl
;
477 dst_pte
= pte_alloc_map_lock(dst_mm
, dst_pmd
, addr
, &dst_ptl
);
480 src_pte
= pte_offset_map_nested(src_pmd
, addr
);
481 src_ptl
= pte_lockptr(src_mm
, src_pmd
);
486 * We are holding two locks at this point - either of them
487 * could generate latencies in another task on another CPU.
489 if (progress
>= 32) {
491 if (need_resched() ||
492 need_lockbreak(src_ptl
) ||
493 need_lockbreak(dst_ptl
))
496 if (pte_none(*src_pte
)) {
500 copy_one_pte(dst_mm
, src_mm
, dst_pte
, src_pte
, vma
, addr
, rss
);
502 } while (dst_pte
++, src_pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
504 spin_unlock(src_ptl
);
505 pte_unmap_nested(src_pte
- 1);
506 add_mm_rss(dst_mm
, rss
[0], rss
[1]);
507 pte_unmap_unlock(dst_pte
- 1, dst_ptl
);
514 static inline int copy_pmd_range(struct mm_struct
*dst_mm
, struct mm_struct
*src_mm
,
515 pud_t
*dst_pud
, pud_t
*src_pud
, struct vm_area_struct
*vma
,
516 unsigned long addr
, unsigned long end
)
518 pmd_t
*src_pmd
, *dst_pmd
;
521 dst_pmd
= pmd_alloc(dst_mm
, dst_pud
, addr
);
524 src_pmd
= pmd_offset(src_pud
, addr
);
526 next
= pmd_addr_end(addr
, end
);
527 if (pmd_none_or_clear_bad(src_pmd
))
529 if (copy_pte_range(dst_mm
, src_mm
, dst_pmd
, src_pmd
,
532 } while (dst_pmd
++, src_pmd
++, addr
= next
, addr
!= end
);
536 static inline int copy_pud_range(struct mm_struct
*dst_mm
, struct mm_struct
*src_mm
,
537 pgd_t
*dst_pgd
, pgd_t
*src_pgd
, struct vm_area_struct
*vma
,
538 unsigned long addr
, unsigned long end
)
540 pud_t
*src_pud
, *dst_pud
;
543 dst_pud
= pud_alloc(dst_mm
, dst_pgd
, addr
);
546 src_pud
= pud_offset(src_pgd
, addr
);
548 next
= pud_addr_end(addr
, end
);
549 if (pud_none_or_clear_bad(src_pud
))
551 if (copy_pmd_range(dst_mm
, src_mm
, dst_pud
, src_pud
,
554 } while (dst_pud
++, src_pud
++, addr
= next
, addr
!= end
);
558 int copy_page_range(struct mm_struct
*dst_mm
, struct mm_struct
*src_mm
,
559 struct vm_area_struct
*vma
)
561 pgd_t
*src_pgd
, *dst_pgd
;
563 unsigned long addr
= vma
->vm_start
;
564 unsigned long end
= vma
->vm_end
;
567 * Don't copy ptes where a page fault will fill them correctly.
568 * Fork becomes much lighter when there are big shared or private
569 * readonly mappings. The tradeoff is that copy_page_range is more
570 * efficient than faulting.
572 if (!(vma
->vm_flags
& (VM_HUGETLB
|VM_NONLINEAR
|VM_PFNMAP
))) {
577 if (is_vm_hugetlb_page(vma
))
578 return copy_hugetlb_page_range(dst_mm
, src_mm
, vma
);
580 dst_pgd
= pgd_offset(dst_mm
, addr
);
581 src_pgd
= pgd_offset(src_mm
, addr
);
583 next
= pgd_addr_end(addr
, end
);
584 if (pgd_none_or_clear_bad(src_pgd
))
586 if (copy_pud_range(dst_mm
, src_mm
, dst_pgd
, src_pgd
,
589 } while (dst_pgd
++, src_pgd
++, addr
= next
, addr
!= end
);
593 static unsigned long zap_pte_range(struct mmu_gather
*tlb
,
594 struct vm_area_struct
*vma
, pmd_t
*pmd
,
595 unsigned long addr
, unsigned long end
,
596 long *zap_work
, struct zap_details
*details
)
598 struct mm_struct
*mm
= tlb
->mm
;
604 pte
= pte_offset_map_lock(mm
, pmd
, addr
, &ptl
);
607 if (pte_none(ptent
)) {
611 if (pte_present(ptent
)) {
614 (*zap_work
) -= PAGE_SIZE
;
616 page
= vm_normal_page(vma
, addr
, ptent
);
617 if (unlikely(details
) && page
) {
619 * unmap_shared_mapping_pages() wants to
620 * invalidate cache without truncating:
621 * unmap shared but keep private pages.
623 if (details
->check_mapping
&&
624 details
->check_mapping
!= page
->mapping
)
627 * Each page->index must be checked when
628 * invalidating or truncating nonlinear.
630 if (details
->nonlinear_vma
&&
631 (page
->index
< details
->first_index
||
632 page
->index
> details
->last_index
))
635 ptent
= ptep_get_and_clear_full(mm
, addr
, pte
,
637 tlb_remove_tlb_entry(tlb
, pte
, addr
);
640 if (unlikely(details
) && details
->nonlinear_vma
641 && linear_page_index(details
->nonlinear_vma
,
642 addr
) != page
->index
)
643 set_pte_at(mm
, addr
, pte
,
644 pgoff_to_pte(page
->index
));
648 if (pte_dirty(ptent
))
649 set_page_dirty(page
);
650 if (pte_young(ptent
))
651 mark_page_accessed(page
);
654 page_remove_rmap(page
);
655 tlb_remove_page(tlb
, page
);
659 * If details->check_mapping, we leave swap entries;
660 * if details->nonlinear_vma, we leave file entries.
662 if (unlikely(details
))
664 if (!pte_file(ptent
))
665 free_swap_and_cache(pte_to_swp_entry(ptent
));
666 pte_clear_full(mm
, addr
, pte
, tlb
->fullmm
);
667 } while (pte
++, addr
+= PAGE_SIZE
, (addr
!= end
&& *zap_work
> 0));
669 add_mm_rss(mm
, file_rss
, anon_rss
);
670 pte_unmap_unlock(pte
- 1, ptl
);
675 static inline unsigned long zap_pmd_range(struct mmu_gather
*tlb
,
676 struct vm_area_struct
*vma
, pud_t
*pud
,
677 unsigned long addr
, unsigned long end
,
678 long *zap_work
, struct zap_details
*details
)
683 pmd
= pmd_offset(pud
, addr
);
685 next
= pmd_addr_end(addr
, end
);
686 if (pmd_none_or_clear_bad(pmd
)) {
690 next
= zap_pte_range(tlb
, vma
, pmd
, addr
, next
,
692 } while (pmd
++, addr
= next
, (addr
!= end
&& *zap_work
> 0));
697 static inline unsigned long zap_pud_range(struct mmu_gather
*tlb
,
698 struct vm_area_struct
*vma
, pgd_t
*pgd
,
699 unsigned long addr
, unsigned long end
,
700 long *zap_work
, struct zap_details
*details
)
705 pud
= pud_offset(pgd
, addr
);
707 next
= pud_addr_end(addr
, end
);
708 if (pud_none_or_clear_bad(pud
)) {
712 next
= zap_pmd_range(tlb
, vma
, pud
, addr
, next
,
714 } while (pud
++, addr
= next
, (addr
!= end
&& *zap_work
> 0));
719 static unsigned long unmap_page_range(struct mmu_gather
*tlb
,
720 struct vm_area_struct
*vma
,
721 unsigned long addr
, unsigned long end
,
722 long *zap_work
, struct zap_details
*details
)
727 if (details
&& !details
->check_mapping
&& !details
->nonlinear_vma
)
731 tlb_start_vma(tlb
, vma
);
732 pgd
= pgd_offset(vma
->vm_mm
, addr
);
734 next
= pgd_addr_end(addr
, end
);
735 if (pgd_none_or_clear_bad(pgd
)) {
739 next
= zap_pud_range(tlb
, vma
, pgd
, addr
, next
,
741 } while (pgd
++, addr
= next
, (addr
!= end
&& *zap_work
> 0));
742 tlb_end_vma(tlb
, vma
);
747 #ifdef CONFIG_PREEMPT
748 # define ZAP_BLOCK_SIZE (8 * PAGE_SIZE)
750 /* No preempt: go for improved straight-line efficiency */
751 # define ZAP_BLOCK_SIZE (1024 * PAGE_SIZE)
755 * unmap_vmas - unmap a range of memory covered by a list of vma's
756 * @tlbp: address of the caller's struct mmu_gather
757 * @vma: the starting vma
758 * @start_addr: virtual address at which to start unmapping
759 * @end_addr: virtual address at which to end unmapping
760 * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
761 * @details: details of nonlinear truncation or shared cache invalidation
763 * Returns the end address of the unmapping (restart addr if interrupted).
765 * Unmap all pages in the vma list.
767 * We aim to not hold locks for too long (for scheduling latency reasons).
768 * So zap pages in ZAP_BLOCK_SIZE bytecounts. This means we need to
769 * return the ending mmu_gather to the caller.
771 * Only addresses between `start' and `end' will be unmapped.
773 * The VMA list must be sorted in ascending virtual address order.
775 * unmap_vmas() assumes that the caller will flush the whole unmapped address
776 * range after unmap_vmas() returns. So the only responsibility here is to
777 * ensure that any thus-far unmapped pages are flushed before unmap_vmas()
778 * drops the lock and schedules.
780 unsigned long unmap_vmas(struct mmu_gather
**tlbp
,
781 struct vm_area_struct
*vma
, unsigned long start_addr
,
782 unsigned long end_addr
, unsigned long *nr_accounted
,
783 struct zap_details
*details
)
785 long zap_work
= ZAP_BLOCK_SIZE
;
786 unsigned long tlb_start
= 0; /* For tlb_finish_mmu */
787 int tlb_start_valid
= 0;
788 unsigned long start
= start_addr
;
789 spinlock_t
*i_mmap_lock
= details
? details
->i_mmap_lock
: NULL
;
790 int fullmm
= (*tlbp
)->fullmm
;
792 for ( ; vma
&& vma
->vm_start
< end_addr
; vma
= vma
->vm_next
) {
795 start
= max(vma
->vm_start
, start_addr
);
796 if (start
>= vma
->vm_end
)
798 end
= min(vma
->vm_end
, end_addr
);
799 if (end
<= vma
->vm_start
)
802 if (vma
->vm_flags
& VM_ACCOUNT
)
803 *nr_accounted
+= (end
- start
) >> PAGE_SHIFT
;
805 while (start
!= end
) {
806 if (!tlb_start_valid
) {
811 if (unlikely(is_vm_hugetlb_page(vma
))) {
812 unmap_hugepage_range(vma
, start
, end
);
813 zap_work
-= (end
- start
) /
814 (HPAGE_SIZE
/ PAGE_SIZE
);
817 start
= unmap_page_range(*tlbp
, vma
,
818 start
, end
, &zap_work
, details
);
821 BUG_ON(start
!= end
);
825 tlb_finish_mmu(*tlbp
, tlb_start
, start
);
827 if (need_resched() ||
828 (i_mmap_lock
&& need_lockbreak(i_mmap_lock
))) {
836 *tlbp
= tlb_gather_mmu(vma
->vm_mm
, fullmm
);
838 zap_work
= ZAP_BLOCK_SIZE
;
842 return start
; /* which is now the end (or restart) address */
846 * zap_page_range - remove user pages in a given range
847 * @vma: vm_area_struct holding the applicable pages
848 * @address: starting address of pages to zap
849 * @size: number of bytes to zap
850 * @details: details of nonlinear truncation or shared cache invalidation
852 unsigned long zap_page_range(struct vm_area_struct
*vma
, unsigned long address
,
853 unsigned long size
, struct zap_details
*details
)
855 struct mm_struct
*mm
= vma
->vm_mm
;
856 struct mmu_gather
*tlb
;
857 unsigned long end
= address
+ size
;
858 unsigned long nr_accounted
= 0;
861 tlb
= tlb_gather_mmu(mm
, 0);
862 update_hiwater_rss(mm
);
863 end
= unmap_vmas(&tlb
, vma
, address
, end
, &nr_accounted
, details
);
865 tlb_finish_mmu(tlb
, address
, end
);
870 * Do a quick page-table lookup for a single page.
872 struct page
*follow_page(struct vm_area_struct
*vma
, unsigned long address
,
881 struct mm_struct
*mm
= vma
->vm_mm
;
883 page
= follow_huge_addr(mm
, address
, flags
& FOLL_WRITE
);
885 BUG_ON(flags
& FOLL_GET
);
890 pgd
= pgd_offset(mm
, address
);
891 if (pgd_none(*pgd
) || unlikely(pgd_bad(*pgd
)))
894 pud
= pud_offset(pgd
, address
);
895 if (pud_none(*pud
) || unlikely(pud_bad(*pud
)))
898 pmd
= pmd_offset(pud
, address
);
899 if (pmd_none(*pmd
) || unlikely(pmd_bad(*pmd
)))
902 if (pmd_huge(*pmd
)) {
903 BUG_ON(flags
& FOLL_GET
);
904 page
= follow_huge_pmd(mm
, address
, pmd
, flags
& FOLL_WRITE
);
908 ptep
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
913 if (!pte_present(pte
))
915 if ((flags
& FOLL_WRITE
) && !pte_write(pte
))
917 page
= vm_normal_page(vma
, address
, pte
);
921 if (flags
& FOLL_GET
)
923 if (flags
& FOLL_TOUCH
) {
924 if ((flags
& FOLL_WRITE
) &&
925 !pte_dirty(pte
) && !PageDirty(page
))
926 set_page_dirty(page
);
927 mark_page_accessed(page
);
930 pte_unmap_unlock(ptep
, ptl
);
936 * When core dumping an enormous anonymous area that nobody
937 * has touched so far, we don't want to allocate page tables.
939 if (flags
& FOLL_ANON
) {
940 page
= ZERO_PAGE(address
);
941 if (flags
& FOLL_GET
)
943 BUG_ON(flags
& FOLL_WRITE
);
948 int get_user_pages(struct task_struct
*tsk
, struct mm_struct
*mm
,
949 unsigned long start
, int len
, int write
, int force
,
950 struct page
**pages
, struct vm_area_struct
**vmas
)
953 unsigned int vm_flags
;
956 * Require read or write permissions.
957 * If 'force' is set, we only require the "MAY" flags.
959 vm_flags
= write
? (VM_WRITE
| VM_MAYWRITE
) : (VM_READ
| VM_MAYREAD
);
960 vm_flags
&= force
? (VM_MAYREAD
| VM_MAYWRITE
) : (VM_READ
| VM_WRITE
);
964 struct vm_area_struct
*vma
;
965 unsigned int foll_flags
;
967 vma
= find_extend_vma(mm
, start
);
968 if (!vma
&& in_gate_area(tsk
, start
)) {
969 unsigned long pg
= start
& PAGE_MASK
;
970 struct vm_area_struct
*gate_vma
= get_gate_vma(tsk
);
975 if (write
) /* user gate pages are read-only */
976 return i
? : -EFAULT
;
978 pgd
= pgd_offset_k(pg
);
980 pgd
= pgd_offset_gate(mm
, pg
);
981 BUG_ON(pgd_none(*pgd
));
982 pud
= pud_offset(pgd
, pg
);
983 BUG_ON(pud_none(*pud
));
984 pmd
= pmd_offset(pud
, pg
);
986 return i
? : -EFAULT
;
987 pte
= pte_offset_map(pmd
, pg
);
988 if (pte_none(*pte
)) {
990 return i
? : -EFAULT
;
993 struct page
*page
= vm_normal_page(gate_vma
, start
, *pte
);
1007 if (!vma
|| (vma
->vm_flags
& VM_IO
)
1008 || !(vm_flags
& vma
->vm_flags
))
1009 return i
? : -EFAULT
;
1011 if (is_vm_hugetlb_page(vma
)) {
1012 i
= follow_hugetlb_page(mm
, vma
, pages
, vmas
,
1017 foll_flags
= FOLL_TOUCH
;
1019 foll_flags
|= FOLL_GET
;
1020 if (!write
&& !(vma
->vm_flags
& VM_LOCKED
) &&
1021 (!vma
->vm_ops
|| !vma
->vm_ops
->nopage
))
1022 foll_flags
|= FOLL_ANON
;
1028 foll_flags
|= FOLL_WRITE
;
1031 while (!(page
= follow_page(vma
, start
, foll_flags
))) {
1033 ret
= __handle_mm_fault(mm
, vma
, start
,
1034 foll_flags
& FOLL_WRITE
);
1036 * The VM_FAULT_WRITE bit tells us that do_wp_page has
1037 * broken COW when necessary, even if maybe_mkwrite
1038 * decided not to set pte_write. We can thus safely do
1039 * subsequent page lookups as if they were reads.
1041 if (ret
& VM_FAULT_WRITE
)
1042 foll_flags
&= ~FOLL_WRITE
;
1044 switch (ret
& ~VM_FAULT_WRITE
) {
1045 case VM_FAULT_MINOR
:
1048 case VM_FAULT_MAJOR
:
1051 case VM_FAULT_SIGBUS
:
1052 return i
? i
: -EFAULT
;
1054 return i
? i
: -ENOMEM
;
1061 flush_dcache_page(page
);
1068 } while (len
&& start
< vma
->vm_end
);
1072 EXPORT_SYMBOL(get_user_pages
);
1074 static int zeromap_pte_range(struct mm_struct
*mm
, pmd_t
*pmd
,
1075 unsigned long addr
, unsigned long end
, pgprot_t prot
)
1080 pte
= pte_alloc_map_lock(mm
, pmd
, addr
, &ptl
);
1084 struct page
*page
= ZERO_PAGE(addr
);
1085 pte_t zero_pte
= pte_wrprotect(mk_pte(page
, prot
));
1086 page_cache_get(page
);
1087 page_add_file_rmap(page
);
1088 inc_mm_counter(mm
, file_rss
);
1089 BUG_ON(!pte_none(*pte
));
1090 set_pte_at(mm
, addr
, pte
, zero_pte
);
1091 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
1092 pte_unmap_unlock(pte
- 1, ptl
);
1096 static inline int zeromap_pmd_range(struct mm_struct
*mm
, pud_t
*pud
,
1097 unsigned long addr
, unsigned long end
, pgprot_t prot
)
1102 pmd
= pmd_alloc(mm
, pud
, addr
);
1106 next
= pmd_addr_end(addr
, end
);
1107 if (zeromap_pte_range(mm
, pmd
, addr
, next
, prot
))
1109 } while (pmd
++, addr
= next
, addr
!= end
);
1113 static inline int zeromap_pud_range(struct mm_struct
*mm
, pgd_t
*pgd
,
1114 unsigned long addr
, unsigned long end
, pgprot_t prot
)
1119 pud
= pud_alloc(mm
, pgd
, addr
);
1123 next
= pud_addr_end(addr
, end
);
1124 if (zeromap_pmd_range(mm
, pud
, addr
, next
, prot
))
1126 } while (pud
++, addr
= next
, addr
!= end
);
1130 int zeromap_page_range(struct vm_area_struct
*vma
,
1131 unsigned long addr
, unsigned long size
, pgprot_t prot
)
1135 unsigned long end
= addr
+ size
;
1136 struct mm_struct
*mm
= vma
->vm_mm
;
1139 BUG_ON(addr
>= end
);
1140 pgd
= pgd_offset(mm
, addr
);
1141 flush_cache_range(vma
, addr
, end
);
1143 next
= pgd_addr_end(addr
, end
);
1144 err
= zeromap_pud_range(mm
, pgd
, addr
, next
, prot
);
1147 } while (pgd
++, addr
= next
, addr
!= end
);
1151 pte_t
* fastcall
get_locked_pte(struct mm_struct
*mm
, unsigned long addr
, spinlock_t
**ptl
)
1153 pgd_t
* pgd
= pgd_offset(mm
, addr
);
1154 pud_t
* pud
= pud_alloc(mm
, pgd
, addr
);
1156 pmd_t
* pmd
= pmd_alloc(mm
, pud
, addr
);
1158 return pte_alloc_map_lock(mm
, pmd
, addr
, ptl
);
1164 * This is the old fallback for page remapping.
1166 * For historical reasons, it only allows reserved pages. Only
1167 * old drivers should use this, and they needed to mark their
1168 * pages reserved for the old functions anyway.
1170 static int insert_page(struct mm_struct
*mm
, unsigned long addr
, struct page
*page
, pgprot_t prot
)
1180 flush_dcache_page(page
);
1181 pte
= get_locked_pte(mm
, addr
, &ptl
);
1185 if (!pte_none(*pte
))
1188 /* Ok, finally just insert the thing.. */
1190 inc_mm_counter(mm
, file_rss
);
1191 page_add_file_rmap(page
);
1192 set_pte_at(mm
, addr
, pte
, mk_pte(page
, prot
));
1196 pte_unmap_unlock(pte
, ptl
);
1202 * This allows drivers to insert individual pages they've allocated
1205 * The page has to be a nice clean _individual_ kernel allocation.
1206 * If you allocate a compound page, you need to have marked it as
1207 * such (__GFP_COMP), or manually just split the page up yourself
1208 * (which is mainly an issue of doing "set_page_count(page, 1)" for
1209 * each sub-page, and then freeing them one by one when you free
1210 * them rather than freeing it as a compound page).
1212 * NOTE! Traditionally this was done with "remap_pfn_range()" which
1213 * took an arbitrary page protection parameter. This doesn't allow
1214 * that. Your vma protection will have to be set up correctly, which
1215 * means that if you want a shared writable mapping, you'd better
1216 * ask for a shared writable mapping!
1218 * The page does not need to be reserved.
1220 int vm_insert_page(struct vm_area_struct
*vma
, unsigned long addr
, struct page
*page
)
1222 if (addr
< vma
->vm_start
|| addr
>= vma
->vm_end
)
1224 if (!page_count(page
))
1226 return insert_page(vma
->vm_mm
, addr
, page
, vma
->vm_page_prot
);
1228 EXPORT_SYMBOL(vm_insert_page
);
1231 * maps a range of physical memory into the requested pages. the old
1232 * mappings are removed. any references to nonexistent pages results
1233 * in null mappings (currently treated as "copy-on-access")
1235 static int remap_pte_range(struct mm_struct
*mm
, pmd_t
*pmd
,
1236 unsigned long addr
, unsigned long end
,
1237 unsigned long pfn
, pgprot_t prot
)
1242 pte
= pte_alloc_map_lock(mm
, pmd
, addr
, &ptl
);
1246 BUG_ON(!pte_none(*pte
));
1247 set_pte_at(mm
, addr
, pte
, pfn_pte(pfn
, prot
));
1249 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
1250 pte_unmap_unlock(pte
- 1, ptl
);
1254 static inline int remap_pmd_range(struct mm_struct
*mm
, pud_t
*pud
,
1255 unsigned long addr
, unsigned long end
,
1256 unsigned long pfn
, pgprot_t prot
)
1261 pfn
-= addr
>> PAGE_SHIFT
;
1262 pmd
= pmd_alloc(mm
, pud
, addr
);
1266 next
= pmd_addr_end(addr
, end
);
1267 if (remap_pte_range(mm
, pmd
, addr
, next
,
1268 pfn
+ (addr
>> PAGE_SHIFT
), prot
))
1270 } while (pmd
++, addr
= next
, addr
!= end
);
1274 static inline int remap_pud_range(struct mm_struct
*mm
, pgd_t
*pgd
,
1275 unsigned long addr
, unsigned long end
,
1276 unsigned long pfn
, pgprot_t prot
)
1281 pfn
-= addr
>> PAGE_SHIFT
;
1282 pud
= pud_alloc(mm
, pgd
, addr
);
1286 next
= pud_addr_end(addr
, end
);
1287 if (remap_pmd_range(mm
, pud
, addr
, next
,
1288 pfn
+ (addr
>> PAGE_SHIFT
), prot
))
1290 } while (pud
++, addr
= next
, addr
!= end
);
1294 /* Note: this is only safe if the mm semaphore is held when called. */
1295 int remap_pfn_range(struct vm_area_struct
*vma
, unsigned long addr
,
1296 unsigned long pfn
, unsigned long size
, pgprot_t prot
)
1300 unsigned long end
= addr
+ PAGE_ALIGN(size
);
1301 struct mm_struct
*mm
= vma
->vm_mm
;
1305 * Physically remapped pages are special. Tell the
1306 * rest of the world about it:
1307 * VM_IO tells people not to look at these pages
1308 * (accesses can have side effects).
1309 * VM_RESERVED is specified all over the place, because
1310 * in 2.4 it kept swapout's vma scan off this vma; but
1311 * in 2.6 the LRU scan won't even find its pages, so this
1312 * flag means no more than count its pages in reserved_vm,
1313 * and omit it from core dump, even when VM_IO turned off.
1314 * VM_PFNMAP tells the core MM that the base pages are just
1315 * raw PFN mappings, and do not have a "struct page" associated
1318 * There's a horrible special case to handle copy-on-write
1319 * behaviour that some programs depend on. We mark the "original"
1320 * un-COW'ed pages by matching them up with "vma->vm_pgoff".
1322 if (!(vma
->vm_flags
& VM_SHARED
)) {
1323 if (addr
!= vma
->vm_start
|| end
!= vma
->vm_end
)
1325 vma
->vm_pgoff
= pfn
;
1328 vma
->vm_flags
|= VM_IO
| VM_RESERVED
| VM_PFNMAP
;
1330 BUG_ON(addr
>= end
);
1331 pfn
-= addr
>> PAGE_SHIFT
;
1332 pgd
= pgd_offset(mm
, addr
);
1333 flush_cache_range(vma
, addr
, end
);
1335 next
= pgd_addr_end(addr
, end
);
1336 err
= remap_pud_range(mm
, pgd
, addr
, next
,
1337 pfn
+ (addr
>> PAGE_SHIFT
), prot
);
1340 } while (pgd
++, addr
= next
, addr
!= end
);
1343 EXPORT_SYMBOL(remap_pfn_range
);
1346 * handle_pte_fault chooses page fault handler according to an entry
1347 * which was read non-atomically. Before making any commitment, on
1348 * those architectures or configurations (e.g. i386 with PAE) which
1349 * might give a mix of unmatched parts, do_swap_page and do_file_page
1350 * must check under lock before unmapping the pte and proceeding
1351 * (but do_wp_page is only called after already making such a check;
1352 * and do_anonymous_page and do_no_page can safely check later on).
1354 static inline int pte_unmap_same(struct mm_struct
*mm
, pmd_t
*pmd
,
1355 pte_t
*page_table
, pte_t orig_pte
)
1358 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
1359 if (sizeof(pte_t
) > sizeof(unsigned long)) {
1360 spinlock_t
*ptl
= pte_lockptr(mm
, pmd
);
1362 same
= pte_same(*page_table
, orig_pte
);
1366 pte_unmap(page_table
);
1371 * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when
1372 * servicing faults for write access. In the normal case, do always want
1373 * pte_mkwrite. But get_user_pages can cause write faults for mappings
1374 * that do not have writing enabled, when used by access_process_vm.
1376 static inline pte_t
maybe_mkwrite(pte_t pte
, struct vm_area_struct
*vma
)
1378 if (likely(vma
->vm_flags
& VM_WRITE
))
1379 pte
= pte_mkwrite(pte
);
1383 static inline void cow_user_page(struct page
*dst
, struct page
*src
, unsigned long va
)
1386 * If the source page was a PFN mapping, we don't have
1387 * a "struct page" for it. We do a best-effort copy by
1388 * just copying from the original user address. If that
1389 * fails, we just zero-fill it. Live with it.
1391 if (unlikely(!src
)) {
1392 void *kaddr
= kmap_atomic(dst
, KM_USER0
);
1393 void __user
*uaddr
= (void __user
*)(va
& PAGE_MASK
);
1396 * This really shouldn't fail, because the page is there
1397 * in the page tables. But it might just be unreadable,
1398 * in which case we just give up and fill the result with
1401 if (__copy_from_user_inatomic(kaddr
, uaddr
, PAGE_SIZE
))
1402 memset(kaddr
, 0, PAGE_SIZE
);
1403 kunmap_atomic(kaddr
, KM_USER0
);
1407 copy_user_highpage(dst
, src
, va
);
1411 * This routine handles present pages, when users try to write
1412 * to a shared page. It is done by copying the page to a new address
1413 * and decrementing the shared-page counter for the old page.
1415 * Note that this routine assumes that the protection checks have been
1416 * done by the caller (the low-level page fault routine in most cases).
1417 * Thus we can safely just mark it writable once we've done any necessary
1420 * We also mark the page dirty at this point even though the page will
1421 * change only once the write actually happens. This avoids a few races,
1422 * and potentially makes it more efficient.
1424 * We enter with non-exclusive mmap_sem (to exclude vma changes,
1425 * but allow concurrent faults), with pte both mapped and locked.
1426 * We return with mmap_sem still held, but pte unmapped and unlocked.
1428 static int do_wp_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
1429 unsigned long address
, pte_t
*page_table
, pmd_t
*pmd
,
1430 spinlock_t
*ptl
, pte_t orig_pte
)
1432 struct page
*old_page
, *new_page
;
1434 int ret
= VM_FAULT_MINOR
;
1436 old_page
= vm_normal_page(vma
, address
, orig_pte
);
1440 if (PageAnon(old_page
) && !TestSetPageLocked(old_page
)) {
1441 int reuse
= can_share_swap_page(old_page
);
1442 unlock_page(old_page
);
1444 flush_cache_page(vma
, address
, pte_pfn(orig_pte
));
1445 entry
= pte_mkyoung(orig_pte
);
1446 entry
= maybe_mkwrite(pte_mkdirty(entry
), vma
);
1447 ptep_set_access_flags(vma
, address
, page_table
, entry
, 1);
1448 update_mmu_cache(vma
, address
, entry
);
1449 lazy_mmu_prot_update(entry
);
1450 ret
|= VM_FAULT_WRITE
;
1456 * Ok, we need to copy. Oh, well..
1458 page_cache_get(old_page
);
1460 pte_unmap_unlock(page_table
, ptl
);
1462 if (unlikely(anon_vma_prepare(vma
)))
1464 if (old_page
== ZERO_PAGE(address
)) {
1465 new_page
= alloc_zeroed_user_highpage(vma
, address
);
1469 new_page
= alloc_page_vma(GFP_HIGHUSER
, vma
, address
);
1472 cow_user_page(new_page
, old_page
, address
);
1476 * Re-check the pte - we dropped the lock
1478 page_table
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
1479 if (likely(pte_same(*page_table
, orig_pte
))) {
1481 page_remove_rmap(old_page
);
1482 if (!PageAnon(old_page
)) {
1483 dec_mm_counter(mm
, file_rss
);
1484 inc_mm_counter(mm
, anon_rss
);
1487 inc_mm_counter(mm
, anon_rss
);
1488 flush_cache_page(vma
, address
, pte_pfn(orig_pte
));
1489 entry
= mk_pte(new_page
, vma
->vm_page_prot
);
1490 entry
= maybe_mkwrite(pte_mkdirty(entry
), vma
);
1491 ptep_establish(vma
, address
, page_table
, entry
);
1492 update_mmu_cache(vma
, address
, entry
);
1493 lazy_mmu_prot_update(entry
);
1494 lru_cache_add_active(new_page
);
1495 page_add_anon_rmap(new_page
, vma
, address
);
1497 /* Free the old page.. */
1498 new_page
= old_page
;
1499 ret
|= VM_FAULT_WRITE
;
1502 page_cache_release(new_page
);
1504 page_cache_release(old_page
);
1506 pte_unmap_unlock(page_table
, ptl
);
1510 page_cache_release(old_page
);
1511 return VM_FAULT_OOM
;
1515 * Helper functions for unmap_mapping_range().
1517 * __ Notes on dropping i_mmap_lock to reduce latency while unmapping __
1519 * We have to restart searching the prio_tree whenever we drop the lock,
1520 * since the iterator is only valid while the lock is held, and anyway
1521 * a later vma might be split and reinserted earlier while lock dropped.
1523 * The list of nonlinear vmas could be handled more efficiently, using
1524 * a placeholder, but handle it in the same way until a need is shown.
1525 * It is important to search the prio_tree before nonlinear list: a vma
1526 * may become nonlinear and be shifted from prio_tree to nonlinear list
1527 * while the lock is dropped; but never shifted from list to prio_tree.
1529 * In order to make forward progress despite restarting the search,
1530 * vm_truncate_count is used to mark a vma as now dealt with, so we can
1531 * quickly skip it next time around. Since the prio_tree search only
1532 * shows us those vmas affected by unmapping the range in question, we
1533 * can't efficiently keep all vmas in step with mapping->truncate_count:
1534 * so instead reset them all whenever it wraps back to 0 (then go to 1).
1535 * mapping->truncate_count and vma->vm_truncate_count are protected by
1538 * In order to make forward progress despite repeatedly restarting some
1539 * large vma, note the restart_addr from unmap_vmas when it breaks out:
1540 * and restart from that address when we reach that vma again. It might
1541 * have been split or merged, shrunk or extended, but never shifted: so
1542 * restart_addr remains valid so long as it remains in the vma's range.
1543 * unmap_mapping_range forces truncate_count to leap over page-aligned
1544 * values so we can save vma's restart_addr in its truncate_count field.
1546 #define is_restart_addr(truncate_count) (!((truncate_count) & ~PAGE_MASK))
1548 static void reset_vma_truncate_counts(struct address_space
*mapping
)
1550 struct vm_area_struct
*vma
;
1551 struct prio_tree_iter iter
;
1553 vma_prio_tree_foreach(vma
, &iter
, &mapping
->i_mmap
, 0, ULONG_MAX
)
1554 vma
->vm_truncate_count
= 0;
1555 list_for_each_entry(vma
, &mapping
->i_mmap_nonlinear
, shared
.vm_set
.list
)
1556 vma
->vm_truncate_count
= 0;
1559 static int unmap_mapping_range_vma(struct vm_area_struct
*vma
,
1560 unsigned long start_addr
, unsigned long end_addr
,
1561 struct zap_details
*details
)
1563 unsigned long restart_addr
;
1567 restart_addr
= vma
->vm_truncate_count
;
1568 if (is_restart_addr(restart_addr
) && start_addr
< restart_addr
) {
1569 start_addr
= restart_addr
;
1570 if (start_addr
>= end_addr
) {
1571 /* Top of vma has been split off since last time */
1572 vma
->vm_truncate_count
= details
->truncate_count
;
1577 restart_addr
= zap_page_range(vma
, start_addr
,
1578 end_addr
- start_addr
, details
);
1579 need_break
= need_resched() ||
1580 need_lockbreak(details
->i_mmap_lock
);
1582 if (restart_addr
>= end_addr
) {
1583 /* We have now completed this vma: mark it so */
1584 vma
->vm_truncate_count
= details
->truncate_count
;
1588 /* Note restart_addr in vma's truncate_count field */
1589 vma
->vm_truncate_count
= restart_addr
;
1594 spin_unlock(details
->i_mmap_lock
);
1596 spin_lock(details
->i_mmap_lock
);
1600 static inline void unmap_mapping_range_tree(struct prio_tree_root
*root
,
1601 struct zap_details
*details
)
1603 struct vm_area_struct
*vma
;
1604 struct prio_tree_iter iter
;
1605 pgoff_t vba
, vea
, zba
, zea
;
1608 vma_prio_tree_foreach(vma
, &iter
, root
,
1609 details
->first_index
, details
->last_index
) {
1610 /* Skip quickly over those we have already dealt with */
1611 if (vma
->vm_truncate_count
== details
->truncate_count
)
1614 vba
= vma
->vm_pgoff
;
1615 vea
= vba
+ ((vma
->vm_end
- vma
->vm_start
) >> PAGE_SHIFT
) - 1;
1616 /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */
1617 zba
= details
->first_index
;
1620 zea
= details
->last_index
;
1624 if (unmap_mapping_range_vma(vma
,
1625 ((zba
- vba
) << PAGE_SHIFT
) + vma
->vm_start
,
1626 ((zea
- vba
+ 1) << PAGE_SHIFT
) + vma
->vm_start
,
1632 static inline void unmap_mapping_range_list(struct list_head
*head
,
1633 struct zap_details
*details
)
1635 struct vm_area_struct
*vma
;
1638 * In nonlinear VMAs there is no correspondence between virtual address
1639 * offset and file offset. So we must perform an exhaustive search
1640 * across *all* the pages in each nonlinear VMA, not just the pages
1641 * whose virtual address lies outside the file truncation point.
1644 list_for_each_entry(vma
, head
, shared
.vm_set
.list
) {
1645 /* Skip quickly over those we have already dealt with */
1646 if (vma
->vm_truncate_count
== details
->truncate_count
)
1648 details
->nonlinear_vma
= vma
;
1649 if (unmap_mapping_range_vma(vma
, vma
->vm_start
,
1650 vma
->vm_end
, details
) < 0)
1656 * unmap_mapping_range - unmap the portion of all mmaps
1657 * in the specified address_space corresponding to the specified
1658 * page range in the underlying file.
1659 * @mapping: the address space containing mmaps to be unmapped.
1660 * @holebegin: byte in first page to unmap, relative to the start of
1661 * the underlying file. This will be rounded down to a PAGE_SIZE
1662 * boundary. Note that this is different from vmtruncate(), which
1663 * must keep the partial page. In contrast, we must get rid of
1665 * @holelen: size of prospective hole in bytes. This will be rounded
1666 * up to a PAGE_SIZE boundary. A holelen of zero truncates to the
1668 * @even_cows: 1 when truncating a file, unmap even private COWed pages;
1669 * but 0 when invalidating pagecache, don't throw away private data.
1671 void unmap_mapping_range(struct address_space
*mapping
,
1672 loff_t
const holebegin
, loff_t
const holelen
, int even_cows
)
1674 struct zap_details details
;
1675 pgoff_t hba
= holebegin
>> PAGE_SHIFT
;
1676 pgoff_t hlen
= (holelen
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1678 /* Check for overflow. */
1679 if (sizeof(holelen
) > sizeof(hlen
)) {
1681 (holebegin
+ holelen
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
1682 if (holeend
& ~(long long)ULONG_MAX
)
1683 hlen
= ULONG_MAX
- hba
+ 1;
1686 details
.check_mapping
= even_cows
? NULL
: mapping
;
1687 details
.nonlinear_vma
= NULL
;
1688 details
.first_index
= hba
;
1689 details
.last_index
= hba
+ hlen
- 1;
1690 if (details
.last_index
< details
.first_index
)
1691 details
.last_index
= ULONG_MAX
;
1692 details
.i_mmap_lock
= &mapping
->i_mmap_lock
;
1694 spin_lock(&mapping
->i_mmap_lock
);
1696 /* serialize i_size write against truncate_count write */
1698 /* Protect against page faults, and endless unmapping loops */
1699 mapping
->truncate_count
++;
1701 * For archs where spin_lock has inclusive semantics like ia64
1702 * this smp_mb() will prevent to read pagetable contents
1703 * before the truncate_count increment is visible to
1707 if (unlikely(is_restart_addr(mapping
->truncate_count
))) {
1708 if (mapping
->truncate_count
== 0)
1709 reset_vma_truncate_counts(mapping
);
1710 mapping
->truncate_count
++;
1712 details
.truncate_count
= mapping
->truncate_count
;
1714 if (unlikely(!prio_tree_empty(&mapping
->i_mmap
)))
1715 unmap_mapping_range_tree(&mapping
->i_mmap
, &details
);
1716 if (unlikely(!list_empty(&mapping
->i_mmap_nonlinear
)))
1717 unmap_mapping_range_list(&mapping
->i_mmap_nonlinear
, &details
);
1718 spin_unlock(&mapping
->i_mmap_lock
);
1720 EXPORT_SYMBOL(unmap_mapping_range
);
1723 * Handle all mappings that got truncated by a "truncate()"
1726 * NOTE! We have to be ready to update the memory sharing
1727 * between the file and the memory map for a potential last
1728 * incomplete page. Ugly, but necessary.
1730 int vmtruncate(struct inode
* inode
, loff_t offset
)
1732 struct address_space
*mapping
= inode
->i_mapping
;
1733 unsigned long limit
;
1735 if (inode
->i_size
< offset
)
1738 * truncation of in-use swapfiles is disallowed - it would cause
1739 * subsequent swapout to scribble on the now-freed blocks.
1741 if (IS_SWAPFILE(inode
))
1743 i_size_write(inode
, offset
);
1744 unmap_mapping_range(mapping
, offset
+ PAGE_SIZE
- 1, 0, 1);
1745 truncate_inode_pages(mapping
, offset
);
1749 limit
= current
->signal
->rlim
[RLIMIT_FSIZE
].rlim_cur
;
1750 if (limit
!= RLIM_INFINITY
&& offset
> limit
)
1752 if (offset
> inode
->i_sb
->s_maxbytes
)
1754 i_size_write(inode
, offset
);
1757 if (inode
->i_op
&& inode
->i_op
->truncate
)
1758 inode
->i_op
->truncate(inode
);
1761 send_sig(SIGXFSZ
, current
, 0);
1768 EXPORT_SYMBOL(vmtruncate
);
1771 * Primitive swap readahead code. We simply read an aligned block of
1772 * (1 << page_cluster) entries in the swap area. This method is chosen
1773 * because it doesn't cost us any seek time. We also make sure to queue
1774 * the 'original' request together with the readahead ones...
1776 * This has been extended to use the NUMA policies from the mm triggering
1779 * Caller must hold down_read on the vma->vm_mm if vma is not NULL.
1781 void swapin_readahead(swp_entry_t entry
, unsigned long addr
,struct vm_area_struct
*vma
)
1784 struct vm_area_struct
*next_vma
= vma
? vma
->vm_next
: NULL
;
1787 struct page
*new_page
;
1788 unsigned long offset
;
1791 * Get the number of handles we should do readahead io to.
1793 num
= valid_swaphandles(entry
, &offset
);
1794 for (i
= 0; i
< num
; offset
++, i
++) {
1795 /* Ok, do the async read-ahead now */
1796 new_page
= read_swap_cache_async(swp_entry(swp_type(entry
),
1797 offset
), vma
, addr
);
1800 page_cache_release(new_page
);
1803 * Find the next applicable VMA for the NUMA policy.
1809 if (addr
>= vma
->vm_end
) {
1811 next_vma
= vma
? vma
->vm_next
: NULL
;
1813 if (vma
&& addr
< vma
->vm_start
)
1816 if (next_vma
&& addr
>= next_vma
->vm_start
) {
1818 next_vma
= vma
->vm_next
;
1823 lru_add_drain(); /* Push any new pages onto the LRU now */
1827 * We enter with non-exclusive mmap_sem (to exclude vma changes,
1828 * but allow concurrent faults), and pte mapped but not yet locked.
1829 * We return with mmap_sem still held, but pte unmapped and unlocked.
1831 static int do_swap_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
1832 unsigned long address
, pte_t
*page_table
, pmd_t
*pmd
,
1833 int write_access
, pte_t orig_pte
)
1839 int ret
= VM_FAULT_MINOR
;
1841 if (!pte_unmap_same(mm
, pmd
, page_table
, orig_pte
))
1844 entry
= pte_to_swp_entry(orig_pte
);
1845 page
= lookup_swap_cache(entry
);
1847 swapin_readahead(entry
, address
, vma
);
1848 page
= read_swap_cache_async(entry
, vma
, address
);
1851 * Back out if somebody else faulted in this pte
1852 * while we released the pte lock.
1854 page_table
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
1855 if (likely(pte_same(*page_table
, orig_pte
)))
1860 /* Had to read the page from swap area: Major fault */
1861 ret
= VM_FAULT_MAJOR
;
1862 inc_page_state(pgmajfault
);
1866 mark_page_accessed(page
);
1870 * Back out if somebody else already faulted in this pte.
1872 page_table
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
1873 if (unlikely(!pte_same(*page_table
, orig_pte
)))
1876 if (unlikely(!PageUptodate(page
))) {
1877 ret
= VM_FAULT_SIGBUS
;
1881 /* The page isn't present yet, go ahead with the fault. */
1883 inc_mm_counter(mm
, anon_rss
);
1884 pte
= mk_pte(page
, vma
->vm_page_prot
);
1885 if (write_access
&& can_share_swap_page(page
)) {
1886 pte
= maybe_mkwrite(pte_mkdirty(pte
), vma
);
1890 flush_icache_page(vma
, page
);
1891 set_pte_at(mm
, address
, page_table
, pte
);
1892 page_add_anon_rmap(page
, vma
, address
);
1896 remove_exclusive_swap_page(page
);
1900 if (do_wp_page(mm
, vma
, address
,
1901 page_table
, pmd
, ptl
, pte
) == VM_FAULT_OOM
)
1906 /* No need to invalidate - it was non-present before */
1907 update_mmu_cache(vma
, address
, pte
);
1908 lazy_mmu_prot_update(pte
);
1910 pte_unmap_unlock(page_table
, ptl
);
1914 pte_unmap_unlock(page_table
, ptl
);
1916 page_cache_release(page
);
1921 * We enter with non-exclusive mmap_sem (to exclude vma changes,
1922 * but allow concurrent faults), and pte mapped but not yet locked.
1923 * We return with mmap_sem still held, but pte unmapped and unlocked.
1925 static int do_anonymous_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
1926 unsigned long address
, pte_t
*page_table
, pmd_t
*pmd
,
1934 /* Allocate our own private page. */
1935 pte_unmap(page_table
);
1937 if (unlikely(anon_vma_prepare(vma
)))
1939 page
= alloc_zeroed_user_highpage(vma
, address
);
1943 entry
= mk_pte(page
, vma
->vm_page_prot
);
1944 entry
= maybe_mkwrite(pte_mkdirty(entry
), vma
);
1946 page_table
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
1947 if (!pte_none(*page_table
))
1949 inc_mm_counter(mm
, anon_rss
);
1950 lru_cache_add_active(page
);
1951 SetPageReferenced(page
);
1952 page_add_anon_rmap(page
, vma
, address
);
1954 /* Map the ZERO_PAGE - vm_page_prot is readonly */
1955 page
= ZERO_PAGE(address
);
1956 page_cache_get(page
);
1957 entry
= mk_pte(page
, vma
->vm_page_prot
);
1959 ptl
= pte_lockptr(mm
, pmd
);
1961 if (!pte_none(*page_table
))
1963 inc_mm_counter(mm
, file_rss
);
1964 page_add_file_rmap(page
);
1967 set_pte_at(mm
, address
, page_table
, entry
);
1969 /* No need to invalidate - it was non-present before */
1970 update_mmu_cache(vma
, address
, entry
);
1971 lazy_mmu_prot_update(entry
);
1973 pte_unmap_unlock(page_table
, ptl
);
1974 return VM_FAULT_MINOR
;
1976 page_cache_release(page
);
1979 return VM_FAULT_OOM
;
1983 * do_no_page() tries to create a new page mapping. It aggressively
1984 * tries to share with existing pages, but makes a separate copy if
1985 * the "write_access" parameter is true in order to avoid the next
1988 * As this is called only for pages that do not currently exist, we
1989 * do not need to flush old virtual caches or the TLB.
1991 * We enter with non-exclusive mmap_sem (to exclude vma changes,
1992 * but allow concurrent faults), and pte mapped but not yet locked.
1993 * We return with mmap_sem still held, but pte unmapped and unlocked.
1995 static int do_no_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
1996 unsigned long address
, pte_t
*page_table
, pmd_t
*pmd
,
2000 struct page
*new_page
;
2001 struct address_space
*mapping
= NULL
;
2003 unsigned int sequence
= 0;
2004 int ret
= VM_FAULT_MINOR
;
2007 pte_unmap(page_table
);
2008 BUG_ON(vma
->vm_flags
& VM_PFNMAP
);
2011 mapping
= vma
->vm_file
->f_mapping
;
2012 sequence
= mapping
->truncate_count
;
2013 smp_rmb(); /* serializes i_size against truncate_count */
2016 new_page
= vma
->vm_ops
->nopage(vma
, address
& PAGE_MASK
, &ret
);
2018 * No smp_rmb is needed here as long as there's a full
2019 * spin_lock/unlock sequence inside the ->nopage callback
2020 * (for the pagecache lookup) that acts as an implicit
2021 * smp_mb() and prevents the i_size read to happen
2022 * after the next truncate_count read.
2025 /* no page was available -- either SIGBUS or OOM */
2026 if (new_page
== NOPAGE_SIGBUS
)
2027 return VM_FAULT_SIGBUS
;
2028 if (new_page
== NOPAGE_OOM
)
2029 return VM_FAULT_OOM
;
2032 * Should we do an early C-O-W break?
2034 if (write_access
&& !(vma
->vm_flags
& VM_SHARED
)) {
2037 if (unlikely(anon_vma_prepare(vma
)))
2039 page
= alloc_page_vma(GFP_HIGHUSER
, vma
, address
);
2042 copy_user_highpage(page
, new_page
, address
);
2043 page_cache_release(new_page
);
2048 page_table
= pte_offset_map_lock(mm
, pmd
, address
, &ptl
);
2050 * For a file-backed vma, someone could have truncated or otherwise
2051 * invalidated this page. If unmap_mapping_range got called,
2052 * retry getting the page.
2054 if (mapping
&& unlikely(sequence
!= mapping
->truncate_count
)) {
2055 pte_unmap_unlock(page_table
, ptl
);
2056 page_cache_release(new_page
);
2058 sequence
= mapping
->truncate_count
;
2064 * This silly early PAGE_DIRTY setting removes a race
2065 * due to the bad i386 page protection. But it's valid
2066 * for other architectures too.
2068 * Note that if write_access is true, we either now have
2069 * an exclusive copy of the page, or this is a shared mapping,
2070 * so we can make it writable and dirty to avoid having to
2071 * handle that later.
2073 /* Only go through if we didn't race with anybody else... */
2074 if (pte_none(*page_table
)) {
2075 flush_icache_page(vma
, new_page
);
2076 entry
= mk_pte(new_page
, vma
->vm_page_prot
);
2078 entry
= maybe_mkwrite(pte_mkdirty(entry
), vma
);
2079 set_pte_at(mm
, address
, page_table
, entry
);
2081 inc_mm_counter(mm
, anon_rss
);
2082 lru_cache_add_active(new_page
);
2083 page_add_anon_rmap(new_page
, vma
, address
);
2085 inc_mm_counter(mm
, file_rss
);
2086 page_add_file_rmap(new_page
);
2089 /* One of our sibling threads was faster, back out. */
2090 page_cache_release(new_page
);
2094 /* no need to invalidate: a not-present page shouldn't be cached */
2095 update_mmu_cache(vma
, address
, entry
);
2096 lazy_mmu_prot_update(entry
);
2098 pte_unmap_unlock(page_table
, ptl
);
2101 page_cache_release(new_page
);
2102 return VM_FAULT_OOM
;
2106 * Fault of a previously existing named mapping. Repopulate the pte
2107 * from the encoded file_pte if possible. This enables swappable
2110 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2111 * but allow concurrent faults), and pte mapped but not yet locked.
2112 * We return with mmap_sem still held, but pte unmapped and unlocked.
2114 static int do_file_page(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
2115 unsigned long address
, pte_t
*page_table
, pmd_t
*pmd
,
2116 int write_access
, pte_t orig_pte
)
2121 if (!pte_unmap_same(mm
, pmd
, page_table
, orig_pte
))
2122 return VM_FAULT_MINOR
;
2124 if (unlikely(!(vma
->vm_flags
& VM_NONLINEAR
))) {
2126 * Page table corrupted: show pte and kill process.
2128 print_bad_pte(vma
, orig_pte
, address
);
2129 return VM_FAULT_OOM
;
2131 /* We can then assume vm->vm_ops && vma->vm_ops->populate */
2133 pgoff
= pte_to_pgoff(orig_pte
);
2134 err
= vma
->vm_ops
->populate(vma
, address
& PAGE_MASK
, PAGE_SIZE
,
2135 vma
->vm_page_prot
, pgoff
, 0);
2137 return VM_FAULT_OOM
;
2139 return VM_FAULT_SIGBUS
;
2140 return VM_FAULT_MAJOR
;
2144 * These routines also need to handle stuff like marking pages dirty
2145 * and/or accessed for architectures that don't do it in hardware (most
2146 * RISC architectures). The early dirtying is also good on the i386.
2148 * There is also a hook called "update_mmu_cache()" that architectures
2149 * with external mmu caches can use to update those (ie the Sparc or
2150 * PowerPC hashed page tables that act as extended TLBs).
2152 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2153 * but allow concurrent faults), and pte mapped but not yet locked.
2154 * We return with mmap_sem still held, but pte unmapped and unlocked.
2156 static inline int handle_pte_fault(struct mm_struct
*mm
,
2157 struct vm_area_struct
*vma
, unsigned long address
,
2158 pte_t
*pte
, pmd_t
*pmd
, int write_access
)
2164 old_entry
= entry
= *pte
;
2165 if (!pte_present(entry
)) {
2166 if (pte_none(entry
)) {
2167 if (!vma
->vm_ops
|| !vma
->vm_ops
->nopage
)
2168 return do_anonymous_page(mm
, vma
, address
,
2169 pte
, pmd
, write_access
);
2170 return do_no_page(mm
, vma
, address
,
2171 pte
, pmd
, write_access
);
2173 if (pte_file(entry
))
2174 return do_file_page(mm
, vma
, address
,
2175 pte
, pmd
, write_access
, entry
);
2176 return do_swap_page(mm
, vma
, address
,
2177 pte
, pmd
, write_access
, entry
);
2180 ptl
= pte_lockptr(mm
, pmd
);
2182 if (unlikely(!pte_same(*pte
, entry
)))
2185 if (!pte_write(entry
))
2186 return do_wp_page(mm
, vma
, address
,
2187 pte
, pmd
, ptl
, entry
);
2188 entry
= pte_mkdirty(entry
);
2190 entry
= pte_mkyoung(entry
);
2191 if (!pte_same(old_entry
, entry
)) {
2192 ptep_set_access_flags(vma
, address
, pte
, entry
, write_access
);
2193 update_mmu_cache(vma
, address
, entry
);
2194 lazy_mmu_prot_update(entry
);
2197 * This is needed only for protection faults but the arch code
2198 * is not yet telling us if this is a protection fault or not.
2199 * This still avoids useless tlb flushes for .text page faults
2203 flush_tlb_page(vma
, address
);
2206 pte_unmap_unlock(pte
, ptl
);
2207 return VM_FAULT_MINOR
;
2211 * By the time we get here, we already hold the mm semaphore
2213 int __handle_mm_fault(struct mm_struct
*mm
, struct vm_area_struct
*vma
,
2214 unsigned long address
, int write_access
)
2221 __set_current_state(TASK_RUNNING
);
2223 inc_page_state(pgfault
);
2225 if (unlikely(is_vm_hugetlb_page(vma
)))
2226 return hugetlb_fault(mm
, vma
, address
, write_access
);
2228 pgd
= pgd_offset(mm
, address
);
2229 pud
= pud_alloc(mm
, pgd
, address
);
2231 return VM_FAULT_OOM
;
2232 pmd
= pmd_alloc(mm
, pud
, address
);
2234 return VM_FAULT_OOM
;
2235 pte
= pte_alloc_map(mm
, pmd
, address
);
2237 return VM_FAULT_OOM
;
2239 return handle_pte_fault(mm
, vma
, address
, pte
, pmd
, write_access
);
2242 #ifndef __PAGETABLE_PUD_FOLDED
2244 * Allocate page upper directory.
2245 * We've already handled the fast-path in-line.
2247 int __pud_alloc(struct mm_struct
*mm
, pgd_t
*pgd
, unsigned long address
)
2249 pud_t
*new = pud_alloc_one(mm
, address
);
2253 spin_lock(&mm
->page_table_lock
);
2254 if (pgd_present(*pgd
)) /* Another has populated it */
2257 pgd_populate(mm
, pgd
, new);
2258 spin_unlock(&mm
->page_table_lock
);
2262 /* Workaround for gcc 2.96 */
2263 int __pud_alloc(struct mm_struct
*mm
, pgd_t
*pgd
, unsigned long address
)
2267 #endif /* __PAGETABLE_PUD_FOLDED */
2269 #ifndef __PAGETABLE_PMD_FOLDED
2271 * Allocate page middle directory.
2272 * We've already handled the fast-path in-line.
2274 int __pmd_alloc(struct mm_struct
*mm
, pud_t
*pud
, unsigned long address
)
2276 pmd_t
*new = pmd_alloc_one(mm
, address
);
2280 spin_lock(&mm
->page_table_lock
);
2281 #ifndef __ARCH_HAS_4LEVEL_HACK
2282 if (pud_present(*pud
)) /* Another has populated it */
2285 pud_populate(mm
, pud
, new);
2287 if (pgd_present(*pud
)) /* Another has populated it */
2290 pgd_populate(mm
, pud
, new);
2291 #endif /* __ARCH_HAS_4LEVEL_HACK */
2292 spin_unlock(&mm
->page_table_lock
);
2296 /* Workaround for gcc 2.96 */
2297 int __pmd_alloc(struct mm_struct
*mm
, pud_t
*pud
, unsigned long address
)
2301 #endif /* __PAGETABLE_PMD_FOLDED */
2303 int make_pages_present(unsigned long addr
, unsigned long end
)
2305 int ret
, len
, write
;
2306 struct vm_area_struct
* vma
;
2308 vma
= find_vma(current
->mm
, addr
);
2311 write
= (vma
->vm_flags
& VM_WRITE
) != 0;
2314 if (end
> vma
->vm_end
)
2316 len
= (end
+PAGE_SIZE
-1)/PAGE_SIZE
-addr
/PAGE_SIZE
;
2317 ret
= get_user_pages(current
, current
->mm
, addr
,
2318 len
, write
, 0, NULL
, NULL
);
2321 return ret
== len
? 0 : -1;
2325 * Map a vmalloc()-space virtual address to the physical page.
2327 struct page
* vmalloc_to_page(void * vmalloc_addr
)
2329 unsigned long addr
= (unsigned long) vmalloc_addr
;
2330 struct page
*page
= NULL
;
2331 pgd_t
*pgd
= pgd_offset_k(addr
);
2336 if (!pgd_none(*pgd
)) {
2337 pud
= pud_offset(pgd
, addr
);
2338 if (!pud_none(*pud
)) {
2339 pmd
= pmd_offset(pud
, addr
);
2340 if (!pmd_none(*pmd
)) {
2341 ptep
= pte_offset_map(pmd
, addr
);
2343 if (pte_present(pte
))
2344 page
= pte_page(pte
);
2352 EXPORT_SYMBOL(vmalloc_to_page
);
2355 * Map a vmalloc()-space virtual address to the physical page frame number.
2357 unsigned long vmalloc_to_pfn(void * vmalloc_addr
)
2359 return page_to_pfn(vmalloc_to_page(vmalloc_addr
));
2362 EXPORT_SYMBOL(vmalloc_to_pfn
);
2364 #if !defined(__HAVE_ARCH_GATE_AREA)
2366 #if defined(AT_SYSINFO_EHDR)
2367 static struct vm_area_struct gate_vma
;
2369 static int __init
gate_vma_init(void)
2371 gate_vma
.vm_mm
= NULL
;
2372 gate_vma
.vm_start
= FIXADDR_USER_START
;
2373 gate_vma
.vm_end
= FIXADDR_USER_END
;
2374 gate_vma
.vm_page_prot
= PAGE_READONLY
;
2375 gate_vma
.vm_flags
= 0;
2378 __initcall(gate_vma_init
);
2381 struct vm_area_struct
*get_gate_vma(struct task_struct
*tsk
)
2383 #ifdef AT_SYSINFO_EHDR
2390 int in_gate_area_no_task(unsigned long addr
)
2392 #ifdef AT_SYSINFO_EHDR
2393 if ((addr
>= FIXADDR_USER_START
) && (addr
< FIXADDR_USER_END
))
2399 #endif /* __HAVE_ARCH_GATE_AREA */
This page took 0.119143 seconds and 6 git commands to generate.