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)
39 #include <linux/kernel_stat.h>
41 #include <linux/hugetlb.h>
42 #include <linux/mman.h>
43 #include <linux/swap.h>
44 #include <linux/highmem.h>
45 #include <linux/pagemap.h>
46 #include <linux/rmap.h>
47 #include <linux/module.h>
48 #include <linux/init.h>
50 #include <asm/pgalloc.h>
51 #include <asm/uaccess.h>
53 #include <asm/tlbflush.h>
54 #include <asm/pgtable.h>
56 #include <linux/swapops.h>
57 #include <linux/elf.h>
59 #ifndef CONFIG_DISCONTIGMEM
60 /* use the per-pgdat data instead for discontigmem - mbligh */
61 unsigned long max_mapnr;
64 EXPORT_SYMBOL(max_mapnr);
65 EXPORT_SYMBOL(mem_map);
68 unsigned long num_physpages;
70 * A number of key systems in x86 including ioremap() rely on the assumption
71 * that high_memory defines the upper bound on direct map memory, then end
72 * of ZONE_NORMAL. Under CONFIG_DISCONTIG this means that max_low_pfn and
73 * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL
77 struct page *highmem_start_page;
78 unsigned long vmalloc_earlyreserve;
80 EXPORT_SYMBOL(num_physpages);
81 EXPORT_SYMBOL(highmem_start_page);
82 EXPORT_SYMBOL(high_memory);
83 EXPORT_SYMBOL(vmalloc_earlyreserve);
86 * We special-case the C-O-W ZERO_PAGE, because it's such
87 * a common occurrence (no need to read the page to know
88 * that it's zero - better for the cache and memory subsystem).
90 static inline void copy_cow_page(struct page * from, struct page * to, unsigned long address)
92 if (from == ZERO_PAGE(address)) {
93 clear_user_highpage(to, address);
96 copy_user_highpage(to, from, address);
100 * Note: this doesn't free the actual pages themselves. That
101 * has been handled earlier when unmapping all the memory regions.
103 static inline void free_one_pmd(struct mmu_gather *tlb, pmd_t * dir)
109 if (unlikely(pmd_bad(*dir))) {
114 page = pmd_page(*dir);
116 dec_page_state(nr_page_table_pages);
118 pte_free_tlb(tlb, page);
121 static inline void free_one_pgd(struct mmu_gather *tlb, pgd_t * dir)
128 if (unlikely(pgd_bad(*dir))) {
133 pmd = pmd_offset(dir, 0);
135 for (j = 0; j < PTRS_PER_PMD ; j++)
136 free_one_pmd(tlb, pmd+j);
137 pmd_free_tlb(tlb, pmd);
141 * This function clears all user-level page tables of a process - this
142 * is needed by execve(), so that old pages aren't in the way.
144 * Must be called with pagetable lock held.
146 void clear_page_tables(struct mmu_gather *tlb, unsigned long first, int nr)
148 pgd_t * page_dir = tlb->mm->pgd;
152 free_one_pgd(tlb, page_dir);
157 pte_t fastcall * pte_alloc_map(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
159 if (!pmd_present(*pmd)) {
162 spin_unlock(&mm->page_table_lock);
163 new = pte_alloc_one(mm, address);
164 spin_lock(&mm->page_table_lock);
168 * Because we dropped the lock, we should re-check the
169 * entry, as somebody else could have populated it..
171 if (pmd_present(*pmd)) {
176 inc_page_state(nr_page_table_pages);
177 pmd_populate(mm, pmd, new);
180 return pte_offset_map(pmd, address);
183 pte_t fastcall * pte_alloc_kernel(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
185 if (!pmd_present(*pmd)) {
188 spin_unlock(&mm->page_table_lock);
189 new = pte_alloc_one_kernel(mm, address);
190 spin_lock(&mm->page_table_lock);
195 * Because we dropped the lock, we should re-check the
196 * entry, as somebody else could have populated it..
198 if (pmd_present(*pmd)) {
199 pte_free_kernel(new);
202 pmd_populate_kernel(mm, pmd, new);
205 return pte_offset_kernel(pmd, address);
207 #define PTE_TABLE_MASK ((PTRS_PER_PTE-1) * sizeof(pte_t))
208 #define PMD_TABLE_MASK ((PTRS_PER_PMD-1) * sizeof(pmd_t))
211 * copy one vm_area from one task to the other. Assumes the page tables
212 * already present in the new task to be cleared in the whole range
213 * covered by this vma.
215 * 08Jan98 Merged into one routine from several inline routines to reduce
216 * variable count and make things faster. -jj
218 * dst->page_table_lock is held on entry and exit,
219 * but may be dropped within pmd_alloc() and pte_alloc_map().
221 int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
222 struct vm_area_struct *vma)
224 pgd_t * src_pgd, * dst_pgd;
225 unsigned long address = vma->vm_start;
226 unsigned long end = vma->vm_end;
229 if (is_vm_hugetlb_page(vma))
230 return copy_hugetlb_page_range(dst, src, vma);
232 cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
233 src_pgd = pgd_offset(src, address)-1;
234 dst_pgd = pgd_offset(dst, address)-1;
237 pmd_t * src_pmd, * dst_pmd;
239 src_pgd++; dst_pgd++;
243 if (pgd_none(*src_pgd))
244 goto skip_copy_pmd_range;
245 if (unlikely(pgd_bad(*src_pgd))) {
248 skip_copy_pmd_range: address = (address + PGDIR_SIZE) & PGDIR_MASK;
249 if (!address || (address >= end))
254 src_pmd = pmd_offset(src_pgd, address);
255 dst_pmd = pmd_alloc(dst, dst_pgd, address);
260 pte_t * src_pte, * dst_pte;
264 if (pmd_none(*src_pmd))
265 goto skip_copy_pte_range;
266 if (unlikely(pmd_bad(*src_pmd))) {
270 address = (address + PMD_SIZE) & PMD_MASK;
273 goto cont_copy_pmd_range;
276 dst_pte = pte_alloc_map(dst, dst_pmd, address);
279 spin_lock(&src->page_table_lock);
280 src_pte = pte_offset_map_nested(src_pmd, address);
282 pte_t pte = *src_pte;
286 if (!vx_rsspages_avail(dst, 1)) {
287 spin_unlock(&src->page_table_lock);
293 goto cont_copy_pte_range_noset;
294 /* pte contains position in swap, so copy. */
295 if (!pte_present(pte)) {
296 if (!pte_file(pte)) {
297 swap_duplicate(pte_to_swp_entry(pte));
298 if (list_empty(&dst->mmlist)) {
299 spin_lock(&mmlist_lock);
300 list_add(&dst->mmlist,
302 spin_unlock(&mmlist_lock);
305 set_pte(dst_pte, pte);
306 goto cont_copy_pte_range_noset;
309 /* the pte points outside of valid memory, the
310 * mapping is assumed to be good, meaningful
311 * and not mapped via rmap - duplicate the
316 page = pfn_to_page(pfn);
318 if (!page || PageReserved(page)) {
319 set_pte(dst_pte, pte);
320 goto cont_copy_pte_range_noset;
324 * If it's a COW mapping, write protect it both
325 * in the parent and the child
328 ptep_set_wrprotect(src_pte);
333 * If it's a shared mapping, mark it clean in
336 if (vma->vm_flags & VM_SHARED)
337 pte = pte_mkclean(pte);
338 pte = pte_mkold(pte);
341 vx_rsspages_inc(dst);
344 set_pte(dst_pte, pte);
346 cont_copy_pte_range_noset:
347 address += PAGE_SIZE;
348 if (address >= end) {
349 pte_unmap_nested(src_pte);
355 } while ((unsigned long)src_pte & PTE_TABLE_MASK);
356 pte_unmap_nested(src_pte-1);
357 pte_unmap(dst_pte-1);
358 spin_unlock(&src->page_table_lock);
359 cond_resched_lock(&dst->page_table_lock);
363 } while ((unsigned long)src_pmd & PMD_TABLE_MASK);
366 spin_unlock(&src->page_table_lock);
373 static void zap_pte_range(struct mmu_gather *tlb,
374 pmd_t *pmd, unsigned long address,
375 unsigned long size, struct zap_details *details)
377 unsigned long offset;
382 if (unlikely(pmd_bad(*pmd))) {
387 ptep = pte_offset_map(pmd, address);
388 offset = address & ~PMD_MASK;
389 if (offset + size > PMD_SIZE)
390 size = PMD_SIZE - offset;
392 if (details && !details->check_mapping && !details->nonlinear_vma)
394 for (offset=0; offset < size; ptep++, offset += PAGE_SIZE) {
398 if (pte_present(pte)) {
399 struct page *page = NULL;
400 unsigned long pfn = pte_pfn(pte);
401 if (pfn_valid(pfn)) {
402 page = pfn_to_page(pfn);
403 if (PageReserved(page))
406 if (unlikely(details) && page) {
408 * unmap_shared_mapping_pages() wants to
409 * invalidate cache without truncating:
410 * unmap shared but keep private pages.
412 if (details->check_mapping &&
413 details->check_mapping != page->mapping)
416 * Each page->index must be checked when
417 * invalidating or truncating nonlinear.
419 if (details->nonlinear_vma &&
420 (page->index < details->first_index ||
421 page->index > details->last_index))
424 pte = ptep_get_and_clear(ptep);
425 tlb_remove_tlb_entry(tlb, ptep, address+offset);
428 if (unlikely(details) && details->nonlinear_vma
429 && linear_page_index(details->nonlinear_vma,
430 address+offset) != page->index)
431 set_pte(ptep, pgoff_to_pte(page->index));
433 set_page_dirty(page);
436 else if (pte_young(pte))
437 mark_page_accessed(page);
439 page_remove_rmap(page);
440 tlb_remove_page(tlb, page);
444 * If details->check_mapping, we leave swap entries;
445 * if details->nonlinear_vma, we leave file entries.
447 if (unlikely(details))
450 free_swap_and_cache(pte_to_swp_entry(pte));
456 static void zap_pmd_range(struct mmu_gather *tlb,
457 pgd_t * dir, unsigned long address,
458 unsigned long size, struct zap_details *details)
465 if (unlikely(pgd_bad(*dir))) {
470 pmd = pmd_offset(dir, address);
471 end = address + size;
472 if (end > ((address + PGDIR_SIZE) & PGDIR_MASK))
473 end = ((address + PGDIR_SIZE) & PGDIR_MASK);
475 zap_pte_range(tlb, pmd, address, end - address, details);
476 address = (address + PMD_SIZE) & PMD_MASK;
478 } while (address && (address < end));
481 static void unmap_page_range(struct mmu_gather *tlb,
482 struct vm_area_struct *vma, unsigned long address,
483 unsigned long end, struct zap_details *details)
487 BUG_ON(address >= end);
488 dir = pgd_offset(vma->vm_mm, address);
489 tlb_start_vma(tlb, vma);
491 zap_pmd_range(tlb, dir, address, end - address, details);
492 address = (address + PGDIR_SIZE) & PGDIR_MASK;
494 } while (address && (address < end));
495 tlb_end_vma(tlb, vma);
498 /* Dispose of an entire struct mmu_gather per rescheduling point */
499 #if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT)
500 #define ZAP_BLOCK_SIZE (FREE_PTE_NR * PAGE_SIZE)
503 /* For UP, 256 pages at a time gives nice low latency */
504 #if !defined(CONFIG_SMP) && defined(CONFIG_PREEMPT)
505 #define ZAP_BLOCK_SIZE (256 * PAGE_SIZE)
508 /* No preempt: go for improved straight-line efficiency */
509 #if !defined(CONFIG_PREEMPT)
510 #define ZAP_BLOCK_SIZE (1024 * PAGE_SIZE)
514 * unmap_vmas - unmap a range of memory covered by a list of vma's
515 * @tlbp: address of the caller's struct mmu_gather
516 * @mm: the controlling mm_struct
517 * @vma: the starting vma
518 * @start_addr: virtual address at which to start unmapping
519 * @end_addr: virtual address at which to end unmapping
520 * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
521 * @details: details of nonlinear truncation or shared cache invalidation
523 * Returns the number of vma's which were covered by the unmapping.
525 * Unmap all pages in the vma list. Called under page_table_lock.
527 * We aim to not hold page_table_lock for too long (for scheduling latency
528 * reasons). So zap pages in ZAP_BLOCK_SIZE bytecounts. This means we need to
529 * return the ending mmu_gather to the caller.
531 * Only addresses between `start' and `end' will be unmapped.
533 * The VMA list must be sorted in ascending virtual address order.
535 * unmap_vmas() assumes that the caller will flush the whole unmapped address
536 * range after unmap_vmas() returns. So the only responsibility here is to
537 * ensure that any thus-far unmapped pages are flushed before unmap_vmas()
538 * drops the lock and schedules.
540 int unmap_vmas(struct mmu_gather **tlbp, struct mm_struct *mm,
541 struct vm_area_struct *vma, unsigned long start_addr,
542 unsigned long end_addr, unsigned long *nr_accounted,
543 struct zap_details *details)
545 unsigned long zap_bytes = ZAP_BLOCK_SIZE;
546 unsigned long tlb_start = 0; /* For tlb_finish_mmu */
547 int tlb_start_valid = 0;
549 int atomic = details && details->atomic;
551 for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) {
555 start = max(vma->vm_start, start_addr);
556 if (start >= vma->vm_end)
558 end = min(vma->vm_end, end_addr);
559 if (end <= vma->vm_start)
562 if (vma->vm_flags & VM_ACCOUNT)
563 *nr_accounted += (end - start) >> PAGE_SHIFT;
566 while (start != end) {
569 if (!tlb_start_valid) {
574 if (is_vm_hugetlb_page(vma)) {
576 unmap_hugepage_range(vma, start, end);
578 block = min(zap_bytes, end - start);
579 unmap_page_range(*tlbp, vma, start,
580 start + block, details);
585 if ((long)zap_bytes > 0)
587 if (!atomic && need_resched()) {
588 int fullmm = tlb_is_full_mm(*tlbp);
589 tlb_finish_mmu(*tlbp, tlb_start, start);
590 cond_resched_lock(&mm->page_table_lock);
591 *tlbp = tlb_gather_mmu(mm, fullmm);
594 zap_bytes = ZAP_BLOCK_SIZE;
601 * zap_page_range - remove user pages in a given range
602 * @vma: vm_area_struct holding the applicable pages
603 * @address: starting address of pages to zap
604 * @size: number of bytes to zap
605 * @details: details of nonlinear truncation or shared cache invalidation
607 void zap_page_range(struct vm_area_struct *vma, unsigned long address,
608 unsigned long size, struct zap_details *details)
610 struct mm_struct *mm = vma->vm_mm;
611 struct mmu_gather *tlb;
612 unsigned long end = address + size;
613 unsigned long nr_accounted = 0;
615 if (is_vm_hugetlb_page(vma)) {
616 zap_hugepage_range(vma, address, size);
621 spin_lock(&mm->page_table_lock);
622 tlb = tlb_gather_mmu(mm, 0);
623 unmap_vmas(&tlb, mm, vma, address, end, &nr_accounted, details);
624 tlb_finish_mmu(tlb, address, end);
625 spin_unlock(&mm->page_table_lock);
629 * Do a quick page-table lookup for a single page.
630 * mm->page_table_lock must be held.
633 follow_page(struct mm_struct *mm, unsigned long address, int write)
641 page = follow_huge_addr(mm, address, write);
645 pgd = pgd_offset(mm, address);
646 if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
649 pmd = pmd_offset(pgd, address);
653 return follow_huge_pmd(mm, address, pmd, write);
654 if (unlikely(pmd_bad(*pmd)))
657 ptep = pte_offset_map(pmd, address);
663 if (pte_present(pte)) {
664 if (write && !pte_write(pte))
667 if (pfn_valid(pfn)) {
668 page = pfn_to_page(pfn);
669 if (write && !pte_dirty(pte) && !PageDirty(page))
670 set_page_dirty(page);
671 mark_page_accessed(page);
681 * Given a physical address, is there a useful struct page pointing to
682 * it? This may become more complex in the future if we start dealing
683 * with IO-aperture pages for direct-IO.
686 static inline struct page *get_page_map(struct page *page)
688 if (!pfn_valid(page_to_pfn(page)))
695 untouched_anonymous_page(struct mm_struct* mm, struct vm_area_struct *vma,
696 unsigned long address)
701 /* Check if the vma is for an anonymous mapping. */
702 if (vma->vm_ops && vma->vm_ops->nopage)
705 /* Check if page directory entry exists. */
706 pgd = pgd_offset(mm, address);
707 if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
710 /* Check if page middle directory entry exists. */
711 pmd = pmd_offset(pgd, address);
712 if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
715 /* There is a pte slot for 'address' in 'mm'. */
720 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
721 unsigned long start, int len, int write, int force,
722 struct page **pages, struct vm_area_struct **vmas)
728 * Require read or write permissions.
729 * If 'force' is set, we only require the "MAY" flags.
731 flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
732 flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
736 struct vm_area_struct * vma;
738 vma = find_extend_vma(mm, start);
739 if (!vma && in_gate_area(tsk, start)) {
740 unsigned long pg = start & PAGE_MASK;
741 struct vm_area_struct *gate_vma = get_gate_vma(tsk);
745 if (write) /* user gate pages are read-only */
746 return i ? : -EFAULT;
748 pgd = pgd_offset_k(pg);
750 pgd = pgd_offset_gate(mm, pg);
751 BUG_ON(pgd_none(*pgd));
752 pmd = pmd_offset(pgd, pg);
753 BUG_ON(pmd_none(*pmd));
754 pte = pte_offset_map(pmd, pg);
755 BUG_ON(pte_none(*pte));
757 pages[i] = pte_page(*pte);
769 if (!vma || (vma->vm_flags & VM_IO)
770 || !(flags & vma->vm_flags))
771 return i ? : -EFAULT;
773 if (is_vm_hugetlb_page(vma)) {
774 i = follow_hugetlb_page(mm, vma, pages, vmas,
778 spin_lock(&mm->page_table_lock);
781 int lookup_write = write;
782 while (!(map = follow_page(mm, start, lookup_write))) {
784 * Shortcut for anonymous pages. We don't want
785 * to force the creation of pages tables for
786 * insanly big anonymously mapped areas that
787 * nobody touched so far. This is important
788 * for doing a core dump for these mappings.
791 untouched_anonymous_page(mm,vma,start)) {
792 map = ZERO_PAGE(start);
795 spin_unlock(&mm->page_table_lock);
796 switch (handle_mm_fault(mm,vma,start,write)) {
803 case VM_FAULT_SIGBUS:
804 return i ? i : -EFAULT;
806 return i ? i : -ENOMEM;
811 * Now that we have performed a write fault
812 * and surely no longer have a shared page we
813 * shouldn't write, we shouldn't ignore an
814 * unwritable page in the page table if
815 * we are forcing write access.
817 lookup_write = write && !force;
818 spin_lock(&mm->page_table_lock);
821 pages[i] = get_page_map(map);
823 spin_unlock(&mm->page_table_lock);
825 page_cache_release(pages[i]);
829 flush_dcache_page(pages[i]);
830 if (!PageReserved(pages[i]))
831 page_cache_get(pages[i]);
838 } while(len && start < vma->vm_end);
839 spin_unlock(&mm->page_table_lock);
845 EXPORT_SYMBOL(get_user_pages);
847 static void zeromap_pte_range(pte_t * pte, unsigned long address,
848 unsigned long size, pgprot_t prot)
852 address &= ~PMD_MASK;
853 end = address + size;
857 pte_t zero_pte = pte_wrprotect(mk_pte(ZERO_PAGE(address), prot));
858 BUG_ON(!pte_none(*pte));
859 set_pte(pte, zero_pte);
860 address += PAGE_SIZE;
862 } while (address && (address < end));
865 static inline int zeromap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address,
866 unsigned long size, pgprot_t prot)
868 unsigned long base, end;
870 base = address & PGDIR_MASK;
871 address &= ~PGDIR_MASK;
872 end = address + size;
873 if (end > PGDIR_SIZE)
876 pte_t * pte = pte_alloc_map(mm, pmd, base + address);
879 zeromap_pte_range(pte, base + address, end - address, prot);
881 address = (address + PMD_SIZE) & PMD_MASK;
883 } while (address && (address < end));
887 int zeromap_page_range(struct vm_area_struct *vma, unsigned long address, unsigned long size, pgprot_t prot)
891 unsigned long beg = address;
892 unsigned long end = address + size;
893 struct mm_struct *mm = vma->vm_mm;
895 dir = pgd_offset(mm, address);
896 flush_cache_range(vma, beg, end);
900 spin_lock(&mm->page_table_lock);
902 pmd_t *pmd = pmd_alloc(mm, dir, address);
906 error = zeromap_pmd_range(mm, pmd, address, end - address, prot);
909 address = (address + PGDIR_SIZE) & PGDIR_MASK;
911 } while (address && (address < end));
913 * Why flush? zeromap_pte_range has a BUG_ON for !pte_none()
915 flush_tlb_range(vma, beg, end);
916 spin_unlock(&mm->page_table_lock);
921 * maps a range of physical memory into the requested pages. the old
922 * mappings are removed. any references to nonexistent pages results
923 * in null mappings (currently treated as "copy-on-access")
925 static inline void remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
926 unsigned long pfn, pgprot_t prot)
930 address &= ~PMD_MASK;
931 end = address + size;
935 BUG_ON(!pte_none(*pte));
936 if (!pfn_valid(pfn) || PageReserved(pfn_to_page(pfn)))
937 set_pte(pte, pfn_pte(pfn, prot));
938 address += PAGE_SIZE;
941 } while (address && (address < end));
944 static inline int remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
945 unsigned long pfn, pgprot_t prot)
947 unsigned long base, end;
949 base = address & PGDIR_MASK;
950 address &= ~PGDIR_MASK;
951 end = address + size;
952 if (end > PGDIR_SIZE)
954 pfn -= address >> PAGE_SHIFT;
956 pte_t * pte = pte_alloc_map(mm, pmd, base + address);
959 remap_pte_range(pte, base + address, end - address, pfn + (address >> PAGE_SHIFT), prot);
961 address = (address + PMD_SIZE) & PMD_MASK;
963 } while (address && (address < end));
967 /* Note: this is only safe if the mm semaphore is held when called. */
968 int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot)
972 unsigned long beg = from;
973 unsigned long end = from + size;
974 struct mm_struct *mm = vma->vm_mm;
976 pfn -= from >> PAGE_SHIFT;
977 dir = pgd_offset(mm, from);
978 flush_cache_range(vma, beg, end);
983 * Physically remapped pages are special. Tell the
984 * rest of the world about it:
985 * VM_IO tells people not to look at these pages
986 * (accesses can have side effects).
987 * VM_RESERVED tells swapout not to try to touch
990 vma->vm_flags |= VM_IO | VM_RESERVED;
991 spin_lock(&mm->page_table_lock);
993 pmd_t *pmd = pmd_alloc(mm, dir, from);
997 error = remap_pmd_range(mm, pmd, from, end - from, pfn + (from >> PAGE_SHIFT), prot);
1000 from = (from + PGDIR_SIZE) & PGDIR_MASK;
1002 } while (from && (from < end));
1004 * Why flush? remap_pte_range has a BUG_ON for !pte_none()
1006 flush_tlb_range(vma, beg, end);
1007 spin_unlock(&mm->page_table_lock);
1010 EXPORT_SYMBOL(remap_pfn_range);
1013 * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when
1014 * servicing faults for write access. In the normal case, do always want
1015 * pte_mkwrite. But get_user_pages can cause write faults for mappings
1016 * that do not have writing enabled, when used by access_process_vm.
1018 static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
1020 if (likely(vma->vm_flags & VM_WRITE))
1021 pte = pte_mkwrite(pte);
1026 * We hold the mm semaphore for reading and vma->vm_mm->page_table_lock
1028 static inline void break_cow(struct vm_area_struct * vma, struct page * new_page, unsigned long address,
1033 flush_cache_page(vma, address);
1034 entry = maybe_mkwrite(pte_mkdirty(mk_pte(new_page, vma->vm_page_prot)),
1036 ptep_establish(vma, address, page_table, entry);
1037 update_mmu_cache(vma, address, entry);
1041 * This routine handles present pages, when users try to write
1042 * to a shared page. It is done by copying the page to a new address
1043 * and decrementing the shared-page counter for the old page.
1045 * Goto-purists beware: the only reason for goto's here is that it results
1046 * in better assembly code.. The "default" path will see no jumps at all.
1048 * Note that this routine assumes that the protection checks have been
1049 * done by the caller (the low-level page fault routine in most cases).
1050 * Thus we can safely just mark it writable once we've done any necessary
1053 * We also mark the page dirty at this point even though the page will
1054 * change only once the write actually happens. This avoids a few races,
1055 * and potentially makes it more efficient.
1057 * We hold the mm semaphore and the page_table_lock on entry and exit
1058 * with the page_table_lock released.
1060 static int do_wp_page(struct mm_struct *mm, struct vm_area_struct * vma,
1061 unsigned long address, pte_t *page_table, pmd_t *pmd, pte_t pte)
1063 struct page *old_page, *new_page;
1064 unsigned long pfn = pte_pfn(pte);
1067 if (unlikely(!pfn_valid(pfn))) {
1069 * This should really halt the system so it can be debugged or
1070 * at least the kernel stops what it's doing before it corrupts
1071 * data, but for the moment just pretend this is OOM.
1073 pte_unmap(page_table);
1074 printk(KERN_ERR "do_wp_page: bogus page at address %08lx\n",
1076 spin_unlock(&mm->page_table_lock);
1077 return VM_FAULT_OOM;
1079 old_page = pfn_to_page(pfn);
1081 if (!TestSetPageLocked(old_page)) {
1082 int reuse = can_share_swap_page(old_page);
1083 unlock_page(old_page);
1085 flush_cache_page(vma, address);
1086 entry = maybe_mkwrite(pte_mkyoung(pte_mkdirty(pte)),
1088 ptep_set_access_flags(vma, address, page_table, entry, 1);
1089 update_mmu_cache(vma, address, entry);
1090 pte_unmap(page_table);
1091 spin_unlock(&mm->page_table_lock);
1092 return VM_FAULT_MINOR;
1095 pte_unmap(page_table);
1098 * Ok, we need to copy. Oh, well..
1100 if (!PageReserved(old_page))
1101 page_cache_get(old_page);
1102 spin_unlock(&mm->page_table_lock);
1104 if (unlikely(anon_vma_prepare(vma)))
1106 new_page = alloc_page_vma(GFP_HIGHUSER, vma, address);
1109 copy_cow_page(old_page,new_page,address);
1112 * Re-check the pte - we dropped the lock
1114 spin_lock(&mm->page_table_lock);
1115 page_table = pte_offset_map(pmd, address);
1116 if (likely(pte_same(*page_table, pte))) {
1117 if (PageAnon(old_page))
1119 if (PageReserved(old_page))
1121 vx_rsspages_inc(mm);
1123 page_remove_rmap(old_page);
1124 break_cow(vma, new_page, address, page_table);
1125 lru_cache_add_active(new_page);
1126 page_add_anon_rmap(new_page, vma, address);
1128 /* Free the old page.. */
1129 new_page = old_page;
1131 pte_unmap(page_table);
1132 page_cache_release(new_page);
1133 page_cache_release(old_page);
1134 spin_unlock(&mm->page_table_lock);
1135 return VM_FAULT_MINOR;
1138 page_cache_release(old_page);
1139 return VM_FAULT_OOM;
1143 * Helper function for unmap_mapping_range().
1145 static inline void unmap_mapping_range_list(struct prio_tree_root *root,
1146 struct zap_details *details)
1148 struct vm_area_struct *vma;
1149 struct prio_tree_iter iter;
1150 pgoff_t vba, vea, zba, zea;
1152 vma_prio_tree_foreach(vma, &iter, root,
1153 details->first_index, details->last_index) {
1154 vba = vma->vm_pgoff;
1155 vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1;
1156 /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */
1157 zba = details->first_index;
1160 zea = details->last_index;
1164 ((zba - vba) << PAGE_SHIFT) + vma->vm_start,
1165 (zea - zba + 1) << PAGE_SHIFT, details);
1170 * unmap_mapping_range - unmap the portion of all mmaps
1171 * in the specified address_space corresponding to the specified
1172 * page range in the underlying file.
1173 * @address_space: the address space containing mmaps to be unmapped.
1174 * @holebegin: byte in first page to unmap, relative to the start of
1175 * the underlying file. This will be rounded down to a PAGE_SIZE
1176 * boundary. Note that this is different from vmtruncate(), which
1177 * must keep the partial page. In contrast, we must get rid of
1179 * @holelen: size of prospective hole in bytes. This will be rounded
1180 * up to a PAGE_SIZE boundary. A holelen of zero truncates to the
1182 * @even_cows: 1 when truncating a file, unmap even private COWed pages;
1183 * but 0 when invalidating pagecache, don't throw away private data.
1185 void unmap_mapping_range(struct address_space *mapping,
1186 loff_t const holebegin, loff_t const holelen, int even_cows)
1188 struct zap_details details;
1189 pgoff_t hba = holebegin >> PAGE_SHIFT;
1190 pgoff_t hlen = (holelen + PAGE_SIZE - 1) >> PAGE_SHIFT;
1192 /* Check for overflow. */
1193 if (sizeof(holelen) > sizeof(hlen)) {
1195 (holebegin + holelen + PAGE_SIZE - 1) >> PAGE_SHIFT;
1196 if (holeend & ~(long long)ULONG_MAX)
1197 hlen = ULONG_MAX - hba + 1;
1200 details.check_mapping = even_cows? NULL: mapping;
1201 details.nonlinear_vma = NULL;
1202 details.first_index = hba;
1203 details.last_index = hba + hlen - 1;
1204 details.atomic = 1; /* A spinlock is held */
1205 if (details.last_index < details.first_index)
1206 details.last_index = ULONG_MAX;
1208 spin_lock(&mapping->i_mmap_lock);
1209 /* Protect against page fault */
1210 atomic_inc(&mapping->truncate_count);
1212 if (unlikely(!prio_tree_empty(&mapping->i_mmap)))
1213 unmap_mapping_range_list(&mapping->i_mmap, &details);
1216 * In nonlinear VMAs there is no correspondence between virtual address
1217 * offset and file offset. So we must perform an exhaustive search
1218 * across *all* the pages in each nonlinear VMA, not just the pages
1219 * whose virtual address lies outside the file truncation point.
1221 if (unlikely(!list_empty(&mapping->i_mmap_nonlinear))) {
1222 struct vm_area_struct *vma;
1223 list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
1224 shared.vm_set.list) {
1225 details.nonlinear_vma = vma;
1226 zap_page_range(vma, vma->vm_start,
1227 vma->vm_end - vma->vm_start, &details);
1230 spin_unlock(&mapping->i_mmap_lock);
1232 EXPORT_SYMBOL(unmap_mapping_range);
1235 * Handle all mappings that got truncated by a "truncate()"
1238 * NOTE! We have to be ready to update the memory sharing
1239 * between the file and the memory map for a potential last
1240 * incomplete page. Ugly, but necessary.
1242 int vmtruncate(struct inode * inode, loff_t offset)
1244 struct address_space *mapping = inode->i_mapping;
1245 unsigned long limit;
1247 if (inode->i_size < offset)
1250 * truncation of in-use swapfiles is disallowed - it would cause
1251 * subsequent swapout to scribble on the now-freed blocks.
1253 if (IS_SWAPFILE(inode))
1255 i_size_write(inode, offset);
1256 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
1257 truncate_inode_pages(mapping, offset);
1261 limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
1262 if (limit != RLIM_INFINITY && offset > limit)
1264 if (offset > inode->i_sb->s_maxbytes)
1266 i_size_write(inode, offset);
1269 if (inode->i_op && inode->i_op->truncate)
1270 inode->i_op->truncate(inode);
1273 send_sig(SIGXFSZ, current, 0);
1280 EXPORT_SYMBOL(vmtruncate);
1283 * Primitive swap readahead code. We simply read an aligned block of
1284 * (1 << page_cluster) entries in the swap area. This method is chosen
1285 * because it doesn't cost us any seek time. We also make sure to queue
1286 * the 'original' request together with the readahead ones...
1288 * This has been extended to use the NUMA policies from the mm triggering
1291 * Caller must hold down_read on the vma->vm_mm if vma is not NULL.
1293 void swapin_readahead(swp_entry_t entry, unsigned long addr,struct vm_area_struct *vma)
1296 struct vm_area_struct *next_vma = vma ? vma->vm_next : NULL;
1299 struct page *new_page;
1300 unsigned long offset;
1303 * Get the number of handles we should do readahead io to.
1305 num = valid_swaphandles(entry, &offset);
1306 for (i = 0; i < num; offset++, i++) {
1307 /* Ok, do the async read-ahead now */
1308 new_page = read_swap_cache_async(swp_entry(swp_type(entry),
1309 offset), vma, addr);
1312 page_cache_release(new_page);
1315 * Find the next applicable VMA for the NUMA policy.
1321 if (addr >= vma->vm_end) {
1323 next_vma = vma ? vma->vm_next : NULL;
1325 if (vma && addr < vma->vm_start)
1328 if (next_vma && addr >= next_vma->vm_start) {
1330 next_vma = vma->vm_next;
1335 lru_add_drain(); /* Push any new pages onto the LRU now */
1339 * We hold the mm semaphore and the page_table_lock on entry and
1340 * should release the pagetable lock on exit..
1342 static int do_swap_page(struct mm_struct * mm,
1343 struct vm_area_struct * vma, unsigned long address,
1344 pte_t *page_table, pmd_t *pmd, pte_t orig_pte, int write_access)
1347 swp_entry_t entry = pte_to_swp_entry(orig_pte);
1349 int ret = VM_FAULT_MINOR;
1351 pte_unmap(page_table);
1352 spin_unlock(&mm->page_table_lock);
1353 page = lookup_swap_cache(entry);
1355 swapin_readahead(entry, address, vma);
1356 page = read_swap_cache_async(entry, vma, address);
1359 * Back out if somebody else faulted in this pte while
1360 * we released the page table lock.
1362 spin_lock(&mm->page_table_lock);
1363 page_table = pte_offset_map(pmd, address);
1364 if (likely(pte_same(*page_table, orig_pte)))
1367 ret = VM_FAULT_MINOR;
1368 pte_unmap(page_table);
1369 spin_unlock(&mm->page_table_lock);
1373 /* Had to read the page from swap area: Major fault */
1374 ret = VM_FAULT_MAJOR;
1375 inc_page_state(pgmajfault);
1379 if (!vx_rsspages_avail(mm, 1)) {
1383 mark_page_accessed(page);
1387 * Back out if somebody else faulted in this pte while we
1388 * released the page table lock.
1390 spin_lock(&mm->page_table_lock);
1391 page_table = pte_offset_map(pmd, address);
1392 if (unlikely(!pte_same(*page_table, orig_pte))) {
1393 pte_unmap(page_table);
1394 spin_unlock(&mm->page_table_lock);
1396 page_cache_release(page);
1397 ret = VM_FAULT_MINOR;
1401 /* The page isn't present yet, go ahead with the fault. */
1405 remove_exclusive_swap_page(page);
1408 vx_rsspages_inc(mm);
1409 pte = mk_pte(page, vma->vm_page_prot);
1410 if (write_access && can_share_swap_page(page)) {
1411 pte = maybe_mkwrite(pte_mkdirty(pte), vma);
1416 flush_icache_page(vma, page);
1417 set_pte(page_table, pte);
1418 page_add_anon_rmap(page, vma, address);
1421 if (do_wp_page(mm, vma, address,
1422 page_table, pmd, pte) == VM_FAULT_OOM)
1427 /* No need to invalidate - it was non-present before */
1428 update_mmu_cache(vma, address, pte);
1429 pte_unmap(page_table);
1430 spin_unlock(&mm->page_table_lock);
1436 * We are called with the MM semaphore and page_table_lock
1437 * spinlock held to protect against concurrent faults in
1438 * multithreaded programs.
1441 do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
1442 pte_t *page_table, pmd_t *pmd, int write_access,
1446 struct page * page = ZERO_PAGE(addr);
1448 /* Read-only mapping of ZERO_PAGE. */
1449 entry = pte_wrprotect(mk_pte(ZERO_PAGE(addr), vma->vm_page_prot));
1451 /* ..except if it's a write access */
1453 /* Allocate our own private page. */
1454 pte_unmap(page_table);
1455 spin_unlock(&mm->page_table_lock);
1457 if (unlikely(anon_vma_prepare(vma)))
1459 if (!vx_rsspages_avail(mm, 1))
1462 page = alloc_page_vma(GFP_HIGHUSER, vma, addr);
1465 clear_user_highpage(page, addr);
1467 spin_lock(&mm->page_table_lock);
1468 page_table = pte_offset_map(pmd, addr);
1470 if (!pte_none(*page_table)) {
1471 pte_unmap(page_table);
1472 page_cache_release(page);
1473 spin_unlock(&mm->page_table_lock);
1477 vx_rsspages_inc(mm);
1478 entry = maybe_mkwrite(pte_mkdirty(mk_pte(page,
1479 vma->vm_page_prot)),
1481 lru_cache_add_active(page);
1482 mark_page_accessed(page);
1483 page_add_anon_rmap(page, vma, addr);
1486 set_pte(page_table, entry);
1487 pte_unmap(page_table);
1489 /* No need to invalidate - it was non-present before */
1490 update_mmu_cache(vma, addr, entry);
1491 spin_unlock(&mm->page_table_lock);
1493 return VM_FAULT_MINOR;
1495 return VM_FAULT_OOM;
1499 * do_no_page() tries to create a new page mapping. It aggressively
1500 * tries to share with existing pages, but makes a separate copy if
1501 * the "write_access" parameter is true in order to avoid the next
1504 * As this is called only for pages that do not currently exist, we
1505 * do not need to flush old virtual caches or the TLB.
1507 * This is called with the MM semaphore held and the page table
1508 * spinlock held. Exit with the spinlock released.
1511 do_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
1512 unsigned long address, int write_access, pte_t *page_table, pmd_t *pmd)
1514 struct page * new_page;
1515 struct address_space *mapping = NULL;
1518 int ret = VM_FAULT_MINOR;
1521 if (!vma->vm_ops || !vma->vm_ops->nopage)
1522 return do_anonymous_page(mm, vma, page_table,
1523 pmd, write_access, address);
1524 pte_unmap(page_table);
1525 spin_unlock(&mm->page_table_lock);
1528 mapping = vma->vm_file->f_mapping;
1529 sequence = atomic_read(&mapping->truncate_count);
1531 smp_rmb(); /* Prevent CPU from reordering lock-free ->nopage() */
1533 new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret);
1535 /* no page was available -- either SIGBUS or OOM */
1536 if (new_page == NOPAGE_SIGBUS)
1537 return VM_FAULT_SIGBUS;
1538 if (new_page == NOPAGE_OOM)
1539 return VM_FAULT_OOM;
1540 if (!vx_rsspages_avail(mm, 1))
1541 return VM_FAULT_OOM;
1544 * Should we do an early C-O-W break?
1546 if (write_access && !(vma->vm_flags & VM_SHARED)) {
1549 if (unlikely(anon_vma_prepare(vma)))
1551 page = alloc_page_vma(GFP_HIGHUSER, vma, address);
1554 copy_user_highpage(page, new_page, address);
1555 page_cache_release(new_page);
1560 spin_lock(&mm->page_table_lock);
1562 * For a file-backed vma, someone could have truncated or otherwise
1563 * invalidated this page. If unmap_mapping_range got called,
1564 * retry getting the page.
1567 (unlikely(sequence != atomic_read(&mapping->truncate_count)))) {
1568 sequence = atomic_read(&mapping->truncate_count);
1569 spin_unlock(&mm->page_table_lock);
1570 page_cache_release(new_page);
1573 page_table = pte_offset_map(pmd, address);
1576 * This silly early PAGE_DIRTY setting removes a race
1577 * due to the bad i386 page protection. But it's valid
1578 * for other architectures too.
1580 * Note that if write_access is true, we either now have
1581 * an exclusive copy of the page, or this is a shared mapping,
1582 * so we can make it writable and dirty to avoid having to
1583 * handle that later.
1585 /* Only go through if we didn't race with anybody else... */
1586 if (pte_none(*page_table)) {
1587 if (!PageReserved(new_page))
1589 vx_rsspages_inc(mm);
1590 flush_icache_page(vma, new_page);
1591 entry = mk_pte(new_page, vma->vm_page_prot);
1593 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
1594 set_pte(page_table, entry);
1596 lru_cache_add_active(new_page);
1597 page_add_anon_rmap(new_page, vma, address);
1599 page_add_file_rmap(new_page);
1600 pte_unmap(page_table);
1602 /* One of our sibling threads was faster, back out. */
1603 pte_unmap(page_table);
1604 page_cache_release(new_page);
1605 spin_unlock(&mm->page_table_lock);
1609 /* no need to invalidate: a not-present page shouldn't be cached */
1610 update_mmu_cache(vma, address, entry);
1611 spin_unlock(&mm->page_table_lock);
1615 page_cache_release(new_page);
1621 * Fault of a previously existing named mapping. Repopulate the pte
1622 * from the encoded file_pte if possible. This enables swappable
1625 static int do_file_page(struct mm_struct * mm, struct vm_area_struct * vma,
1626 unsigned long address, int write_access, pte_t *pte, pmd_t *pmd)
1628 unsigned long pgoff;
1631 BUG_ON(!vma->vm_ops || !vma->vm_ops->nopage);
1633 * Fall back to the linear mapping if the fs does not support
1636 if (!vma->vm_ops || !vma->vm_ops->populate ||
1637 (write_access && !(vma->vm_flags & VM_SHARED))) {
1639 return do_no_page(mm, vma, address, write_access, pte, pmd);
1642 pgoff = pte_to_pgoff(*pte);
1645 spin_unlock(&mm->page_table_lock);
1647 err = vma->vm_ops->populate(vma, address & PAGE_MASK, PAGE_SIZE, vma->vm_page_prot, pgoff, 0);
1649 return VM_FAULT_OOM;
1651 return VM_FAULT_SIGBUS;
1652 return VM_FAULT_MAJOR;
1656 * These routines also need to handle stuff like marking pages dirty
1657 * and/or accessed for architectures that don't do it in hardware (most
1658 * RISC architectures). The early dirtying is also good on the i386.
1660 * There is also a hook called "update_mmu_cache()" that architectures
1661 * with external mmu caches can use to update those (ie the Sparc or
1662 * PowerPC hashed page tables that act as extended TLBs).
1664 * Note the "page_table_lock". It is to protect against kswapd removing
1665 * pages from under us. Note that kswapd only ever _removes_ pages, never
1666 * adds them. As such, once we have noticed that the page is not present,
1667 * we can drop the lock early.
1669 * The adding of pages is protected by the MM semaphore (which we hold),
1670 * so we don't need to worry about a page being suddenly been added into
1673 * We enter with the pagetable spinlock held, we are supposed to
1674 * release it when done.
1676 static inline int handle_pte_fault(struct mm_struct *mm,
1677 struct vm_area_struct * vma, unsigned long address,
1678 int write_access, pte_t *pte, pmd_t *pmd)
1683 if (!pte_present(entry)) {
1685 * If it truly wasn't present, we know that kswapd
1686 * and the PTE updates will not touch it later. So
1689 if (pte_none(entry))
1690 return do_no_page(mm, vma, address, write_access, pte, pmd);
1691 if (pte_file(entry))
1692 return do_file_page(mm, vma, address, write_access, pte, pmd);
1693 return do_swap_page(mm, vma, address, pte, pmd, entry, write_access);
1697 if (!pte_write(entry))
1698 return do_wp_page(mm, vma, address, pte, pmd, entry);
1700 entry = pte_mkdirty(entry);
1702 entry = pte_mkyoung(entry);
1703 ptep_set_access_flags(vma, address, pte, entry, write_access);
1704 update_mmu_cache(vma, address, entry);
1706 spin_unlock(&mm->page_table_lock);
1707 return VM_FAULT_MINOR;
1711 * By the time we get here, we already hold the mm semaphore
1713 int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct * vma,
1714 unsigned long address, int write_access)
1719 __set_current_state(TASK_RUNNING);
1720 pgd = pgd_offset(mm, address);
1722 inc_page_state(pgfault);
1724 if (is_vm_hugetlb_page(vma))
1725 return VM_FAULT_SIGBUS; /* mapping truncation does this. */
1728 * We need the page table lock to synchronize with kswapd
1729 * and the SMP-safe atomic PTE updates.
1731 set_delay_flag(current,PF_MEMIO);
1732 spin_lock(&mm->page_table_lock);
1733 pmd = pmd_alloc(mm, pgd, address);
1736 pte_t * pte = pte_alloc_map(mm, pmd, address);
1738 int rc = handle_pte_fault(mm, vma, address, write_access, pte, pmd);
1739 clear_delay_flag(current,PF_MEMIO);
1743 spin_unlock(&mm->page_table_lock);
1744 clear_delay_flag(current,PF_MEMIO);
1745 return VM_FAULT_OOM;
1749 * Allocate page middle directory.
1751 * We've already handled the fast-path in-line, and we own the
1754 * On a two-level page table, this ends up actually being entirely
1757 pmd_t fastcall *__pmd_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
1761 spin_unlock(&mm->page_table_lock);
1762 new = pmd_alloc_one(mm, address);
1763 spin_lock(&mm->page_table_lock);
1768 * Because we dropped the lock, we should re-check the
1769 * entry, as somebody else could have populated it..
1771 if (pgd_present(*pgd)) {
1775 pgd_populate(mm, pgd, new);
1777 return pmd_offset(pgd, address);
1780 int make_pages_present(unsigned long addr, unsigned long end)
1782 int ret, len, write;
1783 struct vm_area_struct * vma;
1785 vma = find_vma(current->mm, addr);
1788 write = (vma->vm_flags & VM_WRITE) != 0;
1791 if (end > vma->vm_end)
1793 len = (end+PAGE_SIZE-1)/PAGE_SIZE-addr/PAGE_SIZE;
1794 ret = get_user_pages(current, current->mm, addr,
1795 len, write, 0, NULL, NULL);
1798 return ret == len ? 0 : -1;
1802 * Map a vmalloc()-space virtual address to the physical page.
1804 struct page * vmalloc_to_page(void * vmalloc_addr)
1806 unsigned long addr = (unsigned long) vmalloc_addr;
1807 struct page *page = NULL;
1808 pgd_t *pgd = pgd_offset_k(addr);
1812 if (!pgd_none(*pgd)) {
1813 pmd = pmd_offset(pgd, addr);
1814 if (!pmd_none(*pmd)) {
1815 ptep = pte_offset_map(pmd, addr);
1817 if (pte_present(pte))
1818 page = pte_page(pte);
1825 EXPORT_SYMBOL(vmalloc_to_page);
1828 * Map a vmalloc()-space virtual address to the physical page frame number.
1830 unsigned long vmalloc_to_pfn(void * vmalloc_addr)
1832 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
1835 EXPORT_SYMBOL(vmalloc_to_pfn);
1837 #if !defined(CONFIG_ARCH_GATE_AREA)
1839 #if defined(AT_SYSINFO_EHDR)
1840 struct vm_area_struct gate_vma;
1842 static int __init gate_vma_init(void)
1844 gate_vma.vm_mm = NULL;
1845 gate_vma.vm_start = FIXADDR_USER_START;
1846 gate_vma.vm_end = FIXADDR_USER_END;
1847 gate_vma.vm_page_prot = PAGE_READONLY;
1848 gate_vma.vm_flags = 0;
1851 __initcall(gate_vma_init);
1854 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
1856 #ifdef AT_SYSINFO_EHDR
1863 int in_gate_area(struct task_struct *task, unsigned long addr)
1865 #ifdef AT_SYSINFO_EHDR
1866 if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))