4 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
8 * demand-loading started 01.12.91 - seems it is high on the list of
9 * things wanted, and it should be easy to implement. - Linus
13 * Ok, demand-loading was easy, shared pages a little bit tricker. Shared
14 * pages started 02.12.91, seems to work. - Linus.
16 * Tested sharing by executing about 30 /bin/sh: under the old kernel it
17 * would have taken more than the 6M I have free, but it worked well as
20 * Also corrected some "invalidate()"s - I wasn't doing enough of them.
24 * Real VM (paging to/from disk) started 18.12.91. Much more work and
25 * thought has to go into this. Oh, well..
26 * 19.12.91 - works, somewhat. Sometimes I get faults, don't know why.
27 * Found it. Everything seems to work now.
28 * 20.12.91 - Ok, making the swap-device changeable like the root.
32 * 05.04.94 - Multi-page memory management added for v1.1.
33 * Idea by Alex Bligh (alex@cconcepts.co.uk)
35 * 16.07.99 - Support of BIGMEM added by Gerhard Wichert, Siemens AG
36 * (Gerhard.Wichert@pdb.siemens.de)
38 * Aug/Sep 2004 Changed to four level page tables (Andi Kleen)
41 #include <linux/kernel_stat.h>
43 #include <linux/hugetlb.h>
44 #include <linux/mman.h>
45 #include <linux/swap.h>
46 #include <linux/highmem.h>
47 #include <linux/pagemap.h>
48 #include <linux/rmap.h>
49 #include <linux/module.h>
50 #include <linux/delayacct.h>
51 #include <linux/init.h>
52 #include <linux/writeback.h>
54 #include <asm/pgalloc.h>
55 #include <asm/uaccess.h>
57 #include <asm/tlbflush.h>
58 #include <asm/pgtable.h>
60 #include <linux/swapops.h>
61 #include <linux/elf.h>
63 #ifndef CONFIG_NEED_MULTIPLE_NODES
64 /* use the per-pgdat data instead for discontigmem - mbligh */
65 unsigned long max_mapnr;
68 EXPORT_SYMBOL(max_mapnr);
69 EXPORT_SYMBOL(mem_map);
72 unsigned long num_physpages;
74 * A number of key systems in x86 including ioremap() rely on the assumption
75 * that high_memory defines the upper bound on direct map memory, then end
76 * of ZONE_NORMAL. Under CONFIG_DISCONTIG this means that max_low_pfn and
77 * highstart_pfn must be the same; there must be no gap between ZONE_NORMAL
81 unsigned long vmalloc_earlyreserve;
83 EXPORT_SYMBOL(num_physpages);
84 EXPORT_SYMBOL(high_memory);
85 EXPORT_SYMBOL(vmalloc_earlyreserve);
87 int randomize_va_space __read_mostly = 1;
89 static int __init disable_randmaps(char *s)
91 randomize_va_space = 0;
94 __setup("norandmaps", disable_randmaps);
98 * If a p?d_bad entry is found while walking page tables, report
99 * the error, before resetting entry to p?d_none. Usually (but
100 * very seldom) called out from the p?d_none_or_clear_bad macros.
103 void pgd_clear_bad(pgd_t *pgd)
109 void pud_clear_bad(pud_t *pud)
115 void pmd_clear_bad(pmd_t *pmd)
122 * Note: this doesn't free the actual pages themselves. That
123 * has been handled earlier when unmapping all the memory regions.
125 static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd)
127 struct page *page = pmd_page(*pmd);
129 pte_lock_deinit(page);
130 pte_free_tlb(tlb, page);
131 dec_zone_page_state(page, NR_PAGETABLE);
135 static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
136 unsigned long addr, unsigned long end,
137 unsigned long floor, unsigned long ceiling)
144 pmd = pmd_offset(pud, addr);
146 next = pmd_addr_end(addr, end);
147 if (pmd_none_or_clear_bad(pmd))
149 free_pte_range(tlb, pmd);
150 } while (pmd++, addr = next, addr != end);
160 if (end - 1 > ceiling - 1)
163 pmd = pmd_offset(pud, start);
165 pmd_free_tlb(tlb, pmd);
168 static inline void free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
169 unsigned long addr, unsigned long end,
170 unsigned long floor, unsigned long ceiling)
177 pud = pud_offset(pgd, addr);
179 next = pud_addr_end(addr, end);
180 if (pud_none_or_clear_bad(pud))
182 free_pmd_range(tlb, pud, addr, next, floor, ceiling);
183 } while (pud++, addr = next, addr != end);
189 ceiling &= PGDIR_MASK;
193 if (end - 1 > ceiling - 1)
196 pud = pud_offset(pgd, start);
198 pud_free_tlb(tlb, pud);
202 * This function frees user-level page tables of a process.
204 * Must be called with pagetable lock held.
206 void free_pgd_range(struct mmu_gather **tlb,
207 unsigned long addr, unsigned long end,
208 unsigned long floor, unsigned long ceiling)
215 * The next few lines have given us lots of grief...
217 * Why are we testing PMD* at this top level? Because often
218 * there will be no work to do at all, and we'd prefer not to
219 * go all the way down to the bottom just to discover that.
221 * Why all these "- 1"s? Because 0 represents both the bottom
222 * of the address space and the top of it (using -1 for the
223 * top wouldn't help much: the masks would do the wrong thing).
224 * The rule is that addr 0 and floor 0 refer to the bottom of
225 * the address space, but end 0 and ceiling 0 refer to the top
226 * Comparisons need to use "end - 1" and "ceiling - 1" (though
227 * that end 0 case should be mythical).
229 * Wherever addr is brought up or ceiling brought down, we must
230 * be careful to reject "the opposite 0" before it confuses the
231 * subsequent tests. But what about where end is brought down
232 * by PMD_SIZE below? no, end can't go down to 0 there.
234 * Whereas we round start (addr) and ceiling down, by different
235 * masks at different levels, in order to test whether a table
236 * now has no other vmas using it, so can be freed, we don't
237 * bother to round floor or end up - the tests don't need that.
251 if (end - 1 > ceiling - 1)
257 pgd = pgd_offset((*tlb)->mm, addr);
259 next = pgd_addr_end(addr, end);
260 if (pgd_none_or_clear_bad(pgd))
262 free_pud_range(*tlb, pgd, addr, next, floor, ceiling);
263 } while (pgd++, addr = next, addr != end);
266 flush_tlb_pgtables((*tlb)->mm, start, end);
269 void free_pgtables(struct mmu_gather **tlb, struct vm_area_struct *vma,
270 unsigned long floor, unsigned long ceiling)
273 struct vm_area_struct *next = vma->vm_next;
274 unsigned long addr = vma->vm_start;
277 * Hide vma from rmap and vmtruncate before freeing pgtables
279 anon_vma_unlink(vma);
280 unlink_file_vma(vma);
282 if (is_vm_hugetlb_page(vma)) {
283 hugetlb_free_pgd_range(tlb, addr, vma->vm_end,
284 floor, next? next->vm_start: ceiling);
287 * Optimization: gather nearby vmas into one call down
289 while (next && next->vm_start <= vma->vm_end + PMD_SIZE
290 && !is_vm_hugetlb_page(next)) {
293 anon_vma_unlink(vma);
294 unlink_file_vma(vma);
296 free_pgd_range(tlb, addr, vma->vm_end,
297 floor, next? next->vm_start: ceiling);
303 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
305 struct page *new = pte_alloc_one(mm, address);
310 spin_lock(&mm->page_table_lock);
311 if (pmd_present(*pmd)) { /* Another has populated it */
312 pte_lock_deinit(new);
316 inc_zone_page_state(new, NR_PAGETABLE);
317 pmd_populate(mm, pmd, new);
319 spin_unlock(&mm->page_table_lock);
323 int __pte_alloc_kernel(pmd_t *pmd, unsigned long address)
325 pte_t *new = pte_alloc_one_kernel(&init_mm, address);
329 spin_lock(&init_mm.page_table_lock);
330 if (pmd_present(*pmd)) /* Another has populated it */
331 pte_free_kernel(new);
333 pmd_populate_kernel(&init_mm, pmd, new);
334 spin_unlock(&init_mm.page_table_lock);
338 static inline void add_mm_rss(struct mm_struct *mm, int file_rss, int anon_rss)
341 add_mm_counter(mm, file_rss, file_rss);
343 add_mm_counter(mm, anon_rss, anon_rss);
347 * This function is called to print an error when a bad pte
348 * is found. For example, we might have a PFN-mapped pte in
349 * a region that doesn't allow it.
351 * The calling function must still handle the error.
353 void print_bad_pte(struct vm_area_struct *vma, pte_t pte, unsigned long vaddr)
355 printk(KERN_ERR "Bad pte = %08llx, process = %s, "
356 "vm_flags = %lx, vaddr = %lx\n",
357 (long long)pte_val(pte),
358 (vma->vm_mm == current->mm ? current->comm : "???"),
359 vma->vm_flags, vaddr);
363 static inline int is_cow_mapping(unsigned int flags)
365 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
369 * This function gets the "struct page" associated with a pte.
371 * NOTE! Some mappings do not have "struct pages". A raw PFN mapping
372 * will have each page table entry just pointing to a raw page frame
373 * number, and as far as the VM layer is concerned, those do not have
374 * pages associated with them - even if the PFN might point to memory
375 * that otherwise is perfectly fine and has a "struct page".
377 * The way we recognize those mappings is through the rules set up
378 * by "remap_pfn_range()": the vma will have the VM_PFNMAP bit set,
379 * and the vm_pgoff will point to the first PFN mapped: thus every
380 * page that is a raw mapping will always honor the rule
382 * pfn_of_page == vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT)
384 * and if that isn't true, the page has been COW'ed (in which case it
385 * _does_ have a "struct page" associated with it even if it is in a
388 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
390 unsigned long pfn = pte_pfn(pte);
392 if (unlikely(vma->vm_flags & VM_PFNMAP)) {
393 unsigned long off = (addr - vma->vm_start) >> PAGE_SHIFT;
394 if (pfn == vma->vm_pgoff + off)
396 if (!is_cow_mapping(vma->vm_flags))
401 * Add some anal sanity checks for now. Eventually,
402 * we should just do "return pfn_to_page(pfn)", but
403 * in the meantime we check that we get a valid pfn,
404 * and that the resulting page looks ok.
406 if (unlikely(!pfn_valid(pfn))) {
407 if (!(vma->vm_flags & VM_RESERVED))
408 print_bad_pte(vma, pte, addr);
413 * NOTE! We still have PageReserved() pages in the page
416 * The PAGE_ZERO() pages and various VDSO mappings can
417 * cause them to exist.
419 return pfn_to_page(pfn);
423 * copy one vm_area from one task to the other. Assumes the page tables
424 * already present in the new task to be cleared in the whole range
425 * covered by this vma.
429 copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
430 pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma,
431 unsigned long addr, int *rss)
433 unsigned long vm_flags = vma->vm_flags;
434 pte_t pte = *src_pte;
437 /* pte contains position in swap or file, so copy. */
438 if (unlikely(!pte_present(pte))) {
439 if (!pte_file(pte)) {
440 swp_entry_t entry = pte_to_swp_entry(pte);
442 swap_duplicate(entry);
443 /* make sure dst_mm is on swapoff's mmlist. */
444 if (unlikely(list_empty(&dst_mm->mmlist))) {
445 spin_lock(&mmlist_lock);
446 if (list_empty(&dst_mm->mmlist))
447 list_add(&dst_mm->mmlist,
449 spin_unlock(&mmlist_lock);
451 if (is_write_migration_entry(entry) &&
452 is_cow_mapping(vm_flags)) {
454 * COW mappings require pages in both parent
455 * and child to be set to read.
457 make_migration_entry_read(&entry);
458 pte = swp_entry_to_pte(entry);
459 set_pte_at(src_mm, addr, src_pte, pte);
466 * If it's a COW mapping, write protect it both
467 * in the parent and the child
469 if (is_cow_mapping(vm_flags)) {
470 ptep_set_wrprotect(src_mm, addr, src_pte);
475 * If it's a shared mapping, mark it clean in
478 if (vm_flags & VM_SHARED)
479 pte = pte_mkclean(pte);
480 pte = pte_mkold(pte);
482 page = vm_normal_page(vma, addr, pte);
486 rss[!!PageAnon(page)]++;
490 set_pte_at(dst_mm, addr, dst_pte, pte);
493 static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
494 pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma,
495 unsigned long addr, unsigned long end)
497 pte_t *src_pte, *dst_pte;
498 spinlock_t *src_ptl, *dst_ptl;
504 dst_pte = pte_alloc_map_lock(dst_mm, dst_pmd, addr, &dst_ptl);
507 src_pte = pte_offset_map_nested(src_pmd, addr);
508 src_ptl = pte_lockptr(src_mm, src_pmd);
509 spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
513 * We are holding two locks at this point - either of them
514 * could generate latencies in another task on another CPU.
516 if (progress >= 32) {
518 if (need_resched() ||
519 need_lockbreak(src_ptl) ||
520 need_lockbreak(dst_ptl))
523 if (pte_none(*src_pte)) {
527 copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, vma, addr, rss);
529 } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end);
531 spin_unlock(src_ptl);
532 pte_unmap_nested(src_pte - 1);
533 add_mm_rss(dst_mm, rss[0], rss[1]);
534 pte_unmap_unlock(dst_pte - 1, dst_ptl);
541 static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
542 pud_t *dst_pud, pud_t *src_pud, struct vm_area_struct *vma,
543 unsigned long addr, unsigned long end)
545 pmd_t *src_pmd, *dst_pmd;
548 dst_pmd = pmd_alloc(dst_mm, dst_pud, addr);
551 src_pmd = pmd_offset(src_pud, addr);
553 next = pmd_addr_end(addr, end);
554 if (pmd_none_or_clear_bad(src_pmd))
556 if (copy_pte_range(dst_mm, src_mm, dst_pmd, src_pmd,
559 } while (dst_pmd++, src_pmd++, addr = next, addr != end);
563 static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
564 pgd_t *dst_pgd, pgd_t *src_pgd, struct vm_area_struct *vma,
565 unsigned long addr, unsigned long end)
567 pud_t *src_pud, *dst_pud;
570 dst_pud = pud_alloc(dst_mm, dst_pgd, addr);
573 src_pud = pud_offset(src_pgd, addr);
575 next = pud_addr_end(addr, end);
576 if (pud_none_or_clear_bad(src_pud))
578 if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud,
581 } while (dst_pud++, src_pud++, addr = next, addr != end);
585 int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
586 struct vm_area_struct *vma)
588 pgd_t *src_pgd, *dst_pgd;
590 unsigned long addr = vma->vm_start;
591 unsigned long end = vma->vm_end;
594 * Don't copy ptes where a page fault will fill them correctly.
595 * Fork becomes much lighter when there are big shared or private
596 * readonly mappings. The tradeoff is that copy_page_range is more
597 * efficient than faulting.
599 if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_PFNMAP|VM_INSERTPAGE))) {
604 if (is_vm_hugetlb_page(vma))
605 return copy_hugetlb_page_range(dst_mm, src_mm, vma);
607 dst_pgd = pgd_offset(dst_mm, addr);
608 src_pgd = pgd_offset(src_mm, addr);
610 next = pgd_addr_end(addr, end);
611 if (pgd_none_or_clear_bad(src_pgd))
613 if (copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd,
616 } while (dst_pgd++, src_pgd++, addr = next, addr != end);
620 static unsigned long zap_pte_range(struct mmu_gather *tlb,
621 struct vm_area_struct *vma, pmd_t *pmd,
622 unsigned long addr, unsigned long end,
623 long *zap_work, struct zap_details *details)
625 struct mm_struct *mm = tlb->mm;
631 pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
634 if (pte_none(ptent)) {
639 (*zap_work) -= PAGE_SIZE;
641 if (pte_present(ptent)) {
644 page = vm_normal_page(vma, addr, ptent);
645 if (unlikely(details) && page) {
647 * unmap_shared_mapping_pages() wants to
648 * invalidate cache without truncating:
649 * unmap shared but keep private pages.
651 if (details->check_mapping &&
652 details->check_mapping != page->mapping)
655 * Each page->index must be checked when
656 * invalidating or truncating nonlinear.
658 if (details->nonlinear_vma &&
659 (page->index < details->first_index ||
660 page->index > details->last_index))
663 ptent = ptep_get_and_clear_full(mm, addr, pte,
665 tlb_remove_tlb_entry(tlb, pte, addr);
668 if (unlikely(details) && details->nonlinear_vma
669 && linear_page_index(details->nonlinear_vma,
670 addr) != page->index)
671 set_pte_at(mm, addr, pte,
672 pgoff_to_pte(page->index));
676 if (pte_dirty(ptent))
677 set_page_dirty(page);
678 if (pte_young(ptent))
679 mark_page_accessed(page);
682 page_remove_rmap(page, vma);
683 tlb_remove_page(tlb, page);
687 * If details->check_mapping, we leave swap entries;
688 * if details->nonlinear_vma, we leave file entries.
690 if (unlikely(details))
692 if (!pte_file(ptent))
693 free_swap_and_cache(pte_to_swp_entry(ptent));
694 pte_clear_full(mm, addr, pte, tlb->fullmm);
695 } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0));
697 add_mm_rss(mm, file_rss, anon_rss);
698 pte_unmap_unlock(pte - 1, ptl);
703 static inline unsigned long zap_pmd_range(struct mmu_gather *tlb,
704 struct vm_area_struct *vma, pud_t *pud,
705 unsigned long addr, unsigned long end,
706 long *zap_work, struct zap_details *details)
711 pmd = pmd_offset(pud, addr);
713 next = pmd_addr_end(addr, end);
714 if (pmd_none_or_clear_bad(pmd)) {
718 next = zap_pte_range(tlb, vma, pmd, addr, next,
720 } while (pmd++, addr = next, (addr != end && *zap_work > 0));
725 static inline unsigned long zap_pud_range(struct mmu_gather *tlb,
726 struct vm_area_struct *vma, pgd_t *pgd,
727 unsigned long addr, unsigned long end,
728 long *zap_work, struct zap_details *details)
733 pud = pud_offset(pgd, addr);
735 next = pud_addr_end(addr, end);
736 if (pud_none_or_clear_bad(pud)) {
740 next = zap_pmd_range(tlb, vma, pud, addr, next,
742 } while (pud++, addr = next, (addr != end && *zap_work > 0));
747 static unsigned long unmap_page_range(struct mmu_gather *tlb,
748 struct vm_area_struct *vma,
749 unsigned long addr, unsigned long end,
750 long *zap_work, struct zap_details *details)
755 if (details && !details->check_mapping && !details->nonlinear_vma)
759 tlb_start_vma(tlb, vma);
760 pgd = pgd_offset(vma->vm_mm, addr);
762 next = pgd_addr_end(addr, end);
763 if (pgd_none_or_clear_bad(pgd)) {
767 next = zap_pud_range(tlb, vma, pgd, addr, next,
769 } while (pgd++, addr = next, (addr != end && *zap_work > 0));
770 tlb_end_vma(tlb, vma);
775 #ifdef CONFIG_PREEMPT
776 # define ZAP_BLOCK_SIZE (8 * PAGE_SIZE)
778 /* No preempt: go for improved straight-line efficiency */
779 # define ZAP_BLOCK_SIZE (1024 * PAGE_SIZE)
783 * unmap_vmas - unmap a range of memory covered by a list of vma's
784 * @tlbp: address of the caller's struct mmu_gather
785 * @vma: the starting vma
786 * @start_addr: virtual address at which to start unmapping
787 * @end_addr: virtual address at which to end unmapping
788 * @nr_accounted: Place number of unmapped pages in vm-accountable vma's here
789 * @details: details of nonlinear truncation or shared cache invalidation
791 * Returns the end address of the unmapping (restart addr if interrupted).
793 * Unmap all pages in the vma list.
795 * We aim to not hold locks for too long (for scheduling latency reasons).
796 * So zap pages in ZAP_BLOCK_SIZE bytecounts. This means we need to
797 * return the ending mmu_gather to the caller.
799 * Only addresses between `start' and `end' will be unmapped.
801 * The VMA list must be sorted in ascending virtual address order.
803 * unmap_vmas() assumes that the caller will flush the whole unmapped address
804 * range after unmap_vmas() returns. So the only responsibility here is to
805 * ensure that any thus-far unmapped pages are flushed before unmap_vmas()
806 * drops the lock and schedules.
808 unsigned long unmap_vmas(struct mmu_gather **tlbp,
809 struct vm_area_struct *vma, unsigned long start_addr,
810 unsigned long end_addr, unsigned long *nr_accounted,
811 struct zap_details *details)
813 long zap_work = ZAP_BLOCK_SIZE;
814 unsigned long tlb_start = 0; /* For tlb_finish_mmu */
815 int tlb_start_valid = 0;
816 unsigned long start = start_addr;
817 spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL;
818 int fullmm = (*tlbp)->fullmm;
820 for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) {
823 start = max(vma->vm_start, start_addr);
824 if (start >= vma->vm_end)
826 end = min(vma->vm_end, end_addr);
827 if (end <= vma->vm_start)
830 if (vma->vm_flags & VM_ACCOUNT)
831 *nr_accounted += (end - start) >> PAGE_SHIFT;
833 while (start != end) {
834 if (!tlb_start_valid) {
839 if (unlikely(is_vm_hugetlb_page(vma))) {
840 unmap_hugepage_range(vma, start, end);
841 zap_work -= (end - start) /
842 (HPAGE_SIZE / PAGE_SIZE);
845 start = unmap_page_range(*tlbp, vma,
846 start, end, &zap_work, details);
849 BUG_ON(start != end);
853 tlb_finish_mmu(*tlbp, tlb_start, start);
855 if (need_resched() ||
856 (i_mmap_lock && need_lockbreak(i_mmap_lock))) {
864 *tlbp = tlb_gather_mmu(vma->vm_mm, fullmm);
866 zap_work = ZAP_BLOCK_SIZE;
870 return start; /* which is now the end (or restart) address */
874 * zap_page_range - remove user pages in a given range
875 * @vma: vm_area_struct holding the applicable pages
876 * @address: starting address of pages to zap
877 * @size: number of bytes to zap
878 * @details: details of nonlinear truncation or shared cache invalidation
880 unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
881 unsigned long size, struct zap_details *details)
883 struct mm_struct *mm = vma->vm_mm;
884 struct mmu_gather *tlb;
885 unsigned long end = address + size;
886 unsigned long nr_accounted = 0;
889 tlb = tlb_gather_mmu(mm, 0);
890 update_hiwater_rss(mm);
891 end = unmap_vmas(&tlb, vma, address, end, &nr_accounted, details);
893 tlb_finish_mmu(tlb, address, end);
896 EXPORT_SYMBOL(zap_page_range);
899 * Do a quick page-table lookup for a single page.
901 struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
910 struct mm_struct *mm = vma->vm_mm;
912 page = follow_huge_addr(mm, address, flags & FOLL_WRITE);
914 BUG_ON(flags & FOLL_GET);
919 pgd = pgd_offset(mm, address);
920 if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
923 pud = pud_offset(pgd, address);
924 if (pud_none(*pud) || unlikely(pud_bad(*pud)))
927 pmd = pmd_offset(pud, address);
928 if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
931 if (pmd_huge(*pmd)) {
932 BUG_ON(flags & FOLL_GET);
933 page = follow_huge_pmd(mm, address, pmd, flags & FOLL_WRITE);
937 ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
942 if (!pte_present(pte))
944 if ((flags & FOLL_WRITE) && !pte_write(pte))
946 page = vm_normal_page(vma, address, pte);
950 if (flags & FOLL_GET)
952 if (flags & FOLL_TOUCH) {
953 if ((flags & FOLL_WRITE) &&
954 !pte_dirty(pte) && !PageDirty(page))
955 set_page_dirty(page);
956 mark_page_accessed(page);
959 pte_unmap_unlock(ptep, ptl);
965 * When core dumping an enormous anonymous area that nobody
966 * has touched so far, we don't want to allocate page tables.
968 if (flags & FOLL_ANON) {
969 page = ZERO_PAGE(address);
970 if (flags & FOLL_GET)
972 BUG_ON(flags & FOLL_WRITE);
977 int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
978 unsigned long start, int len, int write, int force,
979 struct page **pages, struct vm_area_struct **vmas)
982 unsigned int vm_flags;
985 * Require read or write permissions.
986 * If 'force' is set, we only require the "MAY" flags.
988 vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD);
989 vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE);
993 struct vm_area_struct *vma;
994 unsigned int foll_flags;
996 vma = find_extend_vma(mm, start);
997 if (!vma && in_gate_area(tsk, start)) {
998 unsigned long pg = start & PAGE_MASK;
999 struct vm_area_struct *gate_vma = get_gate_vma(tsk);
1004 if (write) /* user gate pages are read-only */
1005 return i ? : -EFAULT;
1007 pgd = pgd_offset_k(pg);
1009 pgd = pgd_offset_gate(mm, pg);
1010 BUG_ON(pgd_none(*pgd));
1011 pud = pud_offset(pgd, pg);
1012 BUG_ON(pud_none(*pud));
1013 pmd = pmd_offset(pud, pg);
1015 return i ? : -EFAULT;
1016 pte = pte_offset_map(pmd, pg);
1017 if (pte_none(*pte)) {
1019 return i ? : -EFAULT;
1022 struct page *page = vm_normal_page(gate_vma, start, *pte);
1037 if (vma && (vma->vm_flags & VM_FOREIGN)) {
1038 struct page **map = vma->vm_private_data;
1039 int offset = (start - vma->vm_start) >> PAGE_SHIFT;
1040 if (map[offset] != NULL) {
1042 struct page *page = map[offset];
1056 if (!vma || (vma->vm_flags & (VM_IO | VM_PFNMAP))
1057 || !(vm_flags & vma->vm_flags))
1058 return i ? : -EFAULT;
1060 if (is_vm_hugetlb_page(vma)) {
1061 i = follow_hugetlb_page(mm, vma, pages, vmas,
1066 foll_flags = FOLL_TOUCH;
1068 foll_flags |= FOLL_GET;
1069 if (!write && !(vma->vm_flags & VM_LOCKED) &&
1070 (!vma->vm_ops || !vma->vm_ops->nopage))
1071 foll_flags |= FOLL_ANON;
1077 foll_flags |= FOLL_WRITE;
1080 while (!(page = follow_page(vma, start, foll_flags))) {
1082 ret = __handle_mm_fault(mm, vma, start,
1083 foll_flags & FOLL_WRITE);
1085 * The VM_FAULT_WRITE bit tells us that do_wp_page has
1086 * broken COW when necessary, even if maybe_mkwrite
1087 * decided not to set pte_write. We can thus safely do
1088 * subsequent page lookups as if they were reads.
1090 if (ret & VM_FAULT_WRITE)
1091 foll_flags &= ~FOLL_WRITE;
1093 switch (ret & ~VM_FAULT_WRITE) {
1094 case VM_FAULT_MINOR:
1097 case VM_FAULT_MAJOR:
1100 case VM_FAULT_SIGBUS:
1101 return i ? i : -EFAULT;
1103 return i ? i : -ENOMEM;
1111 flush_anon_page(page, start);
1112 flush_dcache_page(page);
1119 } while (len && start < vma->vm_end);
1123 EXPORT_SYMBOL(get_user_pages);
1125 static int zeromap_pte_range(struct mm_struct *mm, pmd_t *pmd,
1126 unsigned long addr, unsigned long end, pgprot_t prot)
1131 pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
1135 struct page *page = ZERO_PAGE(addr);
1136 pte_t zero_pte = pte_wrprotect(mk_pte(page, prot));
1137 page_cache_get(page);
1138 page_add_file_rmap(page);
1139 inc_mm_counter(mm, file_rss);
1140 BUG_ON(!pte_none(*pte));
1141 set_pte_at(mm, addr, pte, zero_pte);
1142 } while (pte++, addr += PAGE_SIZE, addr != end);
1143 pte_unmap_unlock(pte - 1, ptl);
1147 static inline int zeromap_pmd_range(struct mm_struct *mm, pud_t *pud,
1148 unsigned long addr, unsigned long end, pgprot_t prot)
1153 pmd = pmd_alloc(mm, pud, addr);
1157 next = pmd_addr_end(addr, end);
1158 if (zeromap_pte_range(mm, pmd, addr, next, prot))
1160 } while (pmd++, addr = next, addr != end);
1164 static inline int zeromap_pud_range(struct mm_struct *mm, pgd_t *pgd,
1165 unsigned long addr, unsigned long end, pgprot_t prot)
1170 pud = pud_alloc(mm, pgd, addr);
1174 next = pud_addr_end(addr, end);
1175 if (zeromap_pmd_range(mm, pud, addr, next, prot))
1177 } while (pud++, addr = next, addr != end);
1181 int zeromap_page_range(struct vm_area_struct *vma,
1182 unsigned long addr, unsigned long size, pgprot_t prot)
1186 unsigned long end = addr + size;
1187 struct mm_struct *mm = vma->vm_mm;
1190 BUG_ON(addr >= end);
1191 pgd = pgd_offset(mm, addr);
1192 flush_cache_range(vma, addr, end);
1194 next = pgd_addr_end(addr, end);
1195 err = zeromap_pud_range(mm, pgd, addr, next, prot);
1198 } while (pgd++, addr = next, addr != end);
1202 pte_t * fastcall get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl)
1204 pgd_t * pgd = pgd_offset(mm, addr);
1205 pud_t * pud = pud_alloc(mm, pgd, addr);
1207 pmd_t * pmd = pmd_alloc(mm, pud, addr);
1209 return pte_alloc_map_lock(mm, pmd, addr, ptl);
1215 * This is the old fallback for page remapping.
1217 * For historical reasons, it only allows reserved pages. Only
1218 * old drivers should use this, and they needed to mark their
1219 * pages reserved for the old functions anyway.
1221 static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *page, pgprot_t prot)
1231 flush_dcache_page(page);
1232 pte = get_locked_pte(mm, addr, &ptl);
1236 if (!pte_none(*pte))
1239 /* Ok, finally just insert the thing.. */
1241 inc_mm_counter(mm, file_rss);
1242 page_add_file_rmap(page);
1243 set_pte_at(mm, addr, pte, mk_pte(page, prot));
1247 pte_unmap_unlock(pte, ptl);
1253 * This allows drivers to insert individual pages they've allocated
1256 * The page has to be a nice clean _individual_ kernel allocation.
1257 * If you allocate a compound page, you need to have marked it as
1258 * such (__GFP_COMP), or manually just split the page up yourself
1259 * (see split_page()).
1261 * NOTE! Traditionally this was done with "remap_pfn_range()" which
1262 * took an arbitrary page protection parameter. This doesn't allow
1263 * that. Your vma protection will have to be set up correctly, which
1264 * means that if you want a shared writable mapping, you'd better
1265 * ask for a shared writable mapping!
1267 * The page does not need to be reserved.
1269 int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, struct page *page)
1271 if (addr < vma->vm_start || addr >= vma->vm_end)
1273 if (!page_count(page))
1275 vma->vm_flags |= VM_INSERTPAGE;
1276 return insert_page(vma->vm_mm, addr, page, vma->vm_page_prot);
1278 EXPORT_SYMBOL(vm_insert_page);
1281 * maps a range of physical memory into the requested pages. the old
1282 * mappings are removed. any references to nonexistent pages results
1283 * in null mappings (currently treated as "copy-on-access")
1285 static int remap_pte_range(struct mm_struct *mm, pmd_t *pmd,
1286 unsigned long addr, unsigned long end,
1287 unsigned long pfn, pgprot_t prot)
1292 pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
1296 BUG_ON(!pte_none(*pte));
1297 set_pte_at(mm, addr, pte, pfn_pte(pfn, prot));
1299 } while (pte++, addr += PAGE_SIZE, addr != end);
1300 pte_unmap_unlock(pte - 1, ptl);
1304 static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud,
1305 unsigned long addr, unsigned long end,
1306 unsigned long pfn, pgprot_t prot)
1311 pfn -= addr >> PAGE_SHIFT;
1312 pmd = pmd_alloc(mm, pud, addr);
1316 next = pmd_addr_end(addr, end);
1317 if (remap_pte_range(mm, pmd, addr, next,
1318 pfn + (addr >> PAGE_SHIFT), prot))
1320 } while (pmd++, addr = next, addr != end);
1324 static inline int remap_pud_range(struct mm_struct *mm, pgd_t *pgd,
1325 unsigned long addr, unsigned long end,
1326 unsigned long pfn, pgprot_t prot)
1331 pfn -= addr >> PAGE_SHIFT;
1332 pud = pud_alloc(mm, pgd, addr);
1336 next = pud_addr_end(addr, end);
1337 if (remap_pmd_range(mm, pud, addr, next,
1338 pfn + (addr >> PAGE_SHIFT), prot))
1340 } while (pud++, addr = next, addr != end);
1344 /* Note: this is only safe if the mm semaphore is held when called. */
1345 int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
1346 unsigned long pfn, unsigned long size, pgprot_t prot)
1350 unsigned long end = addr + PAGE_ALIGN(size);
1351 struct mm_struct *mm = vma->vm_mm;
1355 * Physically remapped pages are special. Tell the
1356 * rest of the world about it:
1357 * VM_IO tells people not to look at these pages
1358 * (accesses can have side effects).
1359 * VM_RESERVED is specified all over the place, because
1360 * in 2.4 it kept swapout's vma scan off this vma; but
1361 * in 2.6 the LRU scan won't even find its pages, so this
1362 * flag means no more than count its pages in reserved_vm,
1363 * and omit it from core dump, even when VM_IO turned off.
1364 * VM_PFNMAP tells the core MM that the base pages are just
1365 * raw PFN mappings, and do not have a "struct page" associated
1368 * There's a horrible special case to handle copy-on-write
1369 * behaviour that some programs depend on. We mark the "original"
1370 * un-COW'ed pages by matching them up with "vma->vm_pgoff".
1372 if (is_cow_mapping(vma->vm_flags)) {
1373 if (addr != vma->vm_start || end != vma->vm_end)
1375 vma->vm_pgoff = pfn;
1378 vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP;
1380 BUG_ON(addr >= end);
1381 pfn -= addr >> PAGE_SHIFT;
1382 pgd = pgd_offset(mm, addr);
1383 flush_cache_range(vma, addr, end);
1385 next = pgd_addr_end(addr, end);
1386 err = remap_pud_range(mm, pgd, addr, next,
1387 pfn + (addr >> PAGE_SHIFT), prot);
1390 } while (pgd++, addr = next, addr != end);
1393 EXPORT_SYMBOL(remap_pfn_range);
1396 static inline int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
1397 unsigned long addr, unsigned long end,
1398 pte_fn_t fn, void *data)
1402 struct page *pmd_page;
1405 pte = (mm == &init_mm) ?
1406 pte_alloc_kernel(pmd, addr) :
1407 pte_alloc_map_lock(mm, pmd, addr, &ptl);
1411 BUG_ON(pmd_huge(*pmd));
1413 pmd_page = pmd_page(*pmd);
1416 err = fn(pte, pmd_page, addr, data);
1419 } while (pte++, addr += PAGE_SIZE, addr != end);
1422 pte_unmap_unlock(pte-1, ptl);
1426 static inline int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud,
1427 unsigned long addr, unsigned long end,
1428 pte_fn_t fn, void *data)
1434 pmd = pmd_alloc(mm, pud, addr);
1438 next = pmd_addr_end(addr, end);
1439 err = apply_to_pte_range(mm, pmd, addr, next, fn, data);
1442 } while (pmd++, addr = next, addr != end);
1446 static inline int apply_to_pud_range(struct mm_struct *mm, pgd_t *pgd,
1447 unsigned long addr, unsigned long end,
1448 pte_fn_t fn, void *data)
1454 pud = pud_alloc(mm, pgd, addr);
1458 next = pud_addr_end(addr, end);
1459 err = apply_to_pmd_range(mm, pud, addr, next, fn, data);
1462 } while (pud++, addr = next, addr != end);
1467 * Scan a region of virtual memory, filling in page tables as necessary
1468 * and calling a provided function on each leaf page table.
1470 int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
1471 unsigned long size, pte_fn_t fn, void *data)
1475 unsigned long end = addr + size;
1478 BUG_ON(addr >= end);
1479 pgd = pgd_offset(mm, addr);
1481 next = pgd_addr_end(addr, end);
1482 err = apply_to_pud_range(mm, pgd, addr, next, fn, data);
1485 } while (pgd++, addr = next, addr != end);
1488 EXPORT_SYMBOL_GPL(apply_to_page_range);
1492 * handle_pte_fault chooses page fault handler according to an entry
1493 * which was read non-atomically. Before making any commitment, on
1494 * those architectures or configurations (e.g. i386 with PAE) which
1495 * might give a mix of unmatched parts, do_swap_page and do_file_page
1496 * must check under lock before unmapping the pte and proceeding
1497 * (but do_wp_page is only called after already making such a check;
1498 * and do_anonymous_page and do_no_page can safely check later on).
1500 static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,
1501 pte_t *page_table, pte_t orig_pte)
1504 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
1505 if (sizeof(pte_t) > sizeof(unsigned long)) {
1506 spinlock_t *ptl = pte_lockptr(mm, pmd);
1508 same = pte_same(*page_table, orig_pte);
1512 pte_unmap(page_table);
1517 * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when
1518 * servicing faults for write access. In the normal case, do always want
1519 * pte_mkwrite. But get_user_pages can cause write faults for mappings
1520 * that do not have writing enabled, when used by access_process_vm.
1522 static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
1524 if (likely(vma->vm_flags & VM_WRITE))
1525 pte = pte_mkwrite(pte);
1529 static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va)
1532 * If the source page was a PFN mapping, we don't have
1533 * a "struct page" for it. We do a best-effort copy by
1534 * just copying from the original user address. If that
1535 * fails, we just zero-fill it. Live with it.
1537 if (unlikely(!src)) {
1538 void *kaddr = kmap_atomic(dst, KM_USER0);
1539 void __user *uaddr = (void __user *)(va & PAGE_MASK);
1542 * This really shouldn't fail, because the page is there
1543 * in the page tables. But it might just be unreadable,
1544 * in which case we just give up and fill the result with
1547 if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE))
1548 memset(kaddr, 0, PAGE_SIZE);
1549 kunmap_atomic(kaddr, KM_USER0);
1553 copy_user_highpage(dst, src, va);
1557 * This routine handles present pages, when users try to write
1558 * to a shared page. It is done by copying the page to a new address
1559 * and decrementing the shared-page counter for the old page.
1561 * Note that this routine assumes that the protection checks have been
1562 * done by the caller (the low-level page fault routine in most cases).
1563 * Thus we can safely just mark it writable once we've done any necessary
1566 * We also mark the page dirty at this point even though the page will
1567 * change only once the write actually happens. This avoids a few races,
1568 * and potentially makes it more efficient.
1570 * We enter with non-exclusive mmap_sem (to exclude vma changes,
1571 * but allow concurrent faults), with pte both mapped and locked.
1572 * We return with mmap_sem still held, but pte unmapped and unlocked.
1574 static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
1575 unsigned long address, pte_t *page_table, pmd_t *pmd,
1576 spinlock_t *ptl, pte_t orig_pte)
1578 struct page *old_page, *new_page;
1580 int reuse = 0, ret = VM_FAULT_MINOR;
1581 struct page *dirty_page = NULL;
1583 old_page = vm_normal_page(vma, address, orig_pte);
1588 * Take out anonymous pages first, anonymous shared vmas are
1589 * not dirty accountable.
1591 if (PageAnon(old_page)) {
1592 if (!TestSetPageLocked(old_page)) {
1593 reuse = can_share_swap_page(old_page);
1594 unlock_page(old_page);
1596 } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) ==
1597 (VM_WRITE|VM_SHARED))) {
1599 * Only catch write-faults on shared writable pages,
1600 * read-only shared pages can get COWed by
1601 * get_user_pages(.write=1, .force=1).
1603 if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
1605 * Notify the address space that the page is about to
1606 * become writable so that it can prohibit this or wait
1607 * for the page to get into an appropriate state.
1609 * We do this without the lock held, so that it can
1610 * sleep if it needs to.
1612 page_cache_get(old_page);
1613 pte_unmap_unlock(page_table, ptl);
1615 if (vma->vm_ops->page_mkwrite(vma, old_page) < 0)
1616 goto unwritable_page;
1618 page_cache_release(old_page);
1621 * Since we dropped the lock we need to revalidate
1622 * the PTE as someone else may have changed it. If
1623 * they did, we just return, as we can count on the
1624 * MMU to tell us if they didn't also make it writable.
1626 page_table = pte_offset_map_lock(mm, pmd, address,
1628 if (!pte_same(*page_table, orig_pte))
1631 dirty_page = old_page;
1632 get_page(dirty_page);
1637 flush_cache_page(vma, address, pte_pfn(orig_pte));
1638 entry = pte_mkyoung(orig_pte);
1639 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
1640 ptep_set_access_flags(vma, address, page_table, entry, 1);
1641 update_mmu_cache(vma, address, entry);
1642 lazy_mmu_prot_update(entry);
1643 ret |= VM_FAULT_WRITE;
1648 * Ok, we need to copy. Oh, well..
1650 page_cache_get(old_page);
1652 pte_unmap_unlock(page_table, ptl);
1654 if (unlikely(anon_vma_prepare(vma)))
1656 if (old_page == ZERO_PAGE(address)) {
1657 new_page = alloc_zeroed_user_highpage(vma, address);
1661 new_page = alloc_page_vma(GFP_HIGHUSER, vma, address);
1664 cow_user_page(new_page, old_page, address);
1668 * Re-check the pte - we dropped the lock
1670 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
1671 if (likely(pte_same(*page_table, orig_pte))) {
1673 page_remove_rmap(old_page, vma);
1674 if (!PageAnon(old_page)) {
1675 dec_mm_counter(mm, file_rss);
1676 inc_mm_counter(mm, anon_rss);
1679 inc_mm_counter(mm, anon_rss);
1680 flush_cache_page(vma, address, pte_pfn(orig_pte));
1681 entry = mk_pte(new_page, vma->vm_page_prot);
1682 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
1683 lazy_mmu_prot_update(entry);
1685 * Clear the pte entry and flush it first, before updating the
1686 * pte with the new entry. This will avoid a race condition
1687 * seen in the presence of one thread doing SMC and another
1690 ptep_clear_flush(vma, address, page_table);
1691 set_pte_at(mm, address, page_table, entry);
1692 update_mmu_cache(vma, address, entry);
1693 lru_cache_add_active(new_page);
1694 page_add_new_anon_rmap(new_page, vma, address);
1696 /* Free the old page.. */
1697 new_page = old_page;
1698 ret |= VM_FAULT_WRITE;
1701 page_cache_release(new_page);
1703 page_cache_release(old_page);
1705 pte_unmap_unlock(page_table, ptl);
1707 set_page_dirty_balance(dirty_page);
1708 put_page(dirty_page);
1713 page_cache_release(old_page);
1714 return VM_FAULT_OOM;
1717 page_cache_release(old_page);
1718 return VM_FAULT_SIGBUS;
1722 * Helper functions for unmap_mapping_range().
1724 * __ Notes on dropping i_mmap_lock to reduce latency while unmapping __
1726 * We have to restart searching the prio_tree whenever we drop the lock,
1727 * since the iterator is only valid while the lock is held, and anyway
1728 * a later vma might be split and reinserted earlier while lock dropped.
1730 * The list of nonlinear vmas could be handled more efficiently, using
1731 * a placeholder, but handle it in the same way until a need is shown.
1732 * It is important to search the prio_tree before nonlinear list: a vma
1733 * may become nonlinear and be shifted from prio_tree to nonlinear list
1734 * while the lock is dropped; but never shifted from list to prio_tree.
1736 * In order to make forward progress despite restarting the search,
1737 * vm_truncate_count is used to mark a vma as now dealt with, so we can
1738 * quickly skip it next time around. Since the prio_tree search only
1739 * shows us those vmas affected by unmapping the range in question, we
1740 * can't efficiently keep all vmas in step with mapping->truncate_count:
1741 * so instead reset them all whenever it wraps back to 0 (then go to 1).
1742 * mapping->truncate_count and vma->vm_truncate_count are protected by
1745 * In order to make forward progress despite repeatedly restarting some
1746 * large vma, note the restart_addr from unmap_vmas when it breaks out:
1747 * and restart from that address when we reach that vma again. It might
1748 * have been split or merged, shrunk or extended, but never shifted: so
1749 * restart_addr remains valid so long as it remains in the vma's range.
1750 * unmap_mapping_range forces truncate_count to leap over page-aligned
1751 * values so we can save vma's restart_addr in its truncate_count field.
1753 #define is_restart_addr(truncate_count) (!((truncate_count) & ~PAGE_MASK))
1755 static void reset_vma_truncate_counts(struct address_space *mapping)
1757 struct vm_area_struct *vma;
1758 struct prio_tree_iter iter;
1760 vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, 0, ULONG_MAX)
1761 vma->vm_truncate_count = 0;
1762 list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list)
1763 vma->vm_truncate_count = 0;
1766 static int unmap_mapping_range_vma(struct vm_area_struct *vma,
1767 unsigned long start_addr, unsigned long end_addr,
1768 struct zap_details *details)
1770 unsigned long restart_addr;
1774 restart_addr = vma->vm_truncate_count;
1775 if (is_restart_addr(restart_addr) && start_addr < restart_addr) {
1776 start_addr = restart_addr;
1777 if (start_addr >= end_addr) {
1778 /* Top of vma has been split off since last time */
1779 vma->vm_truncate_count = details->truncate_count;
1784 restart_addr = zap_page_range(vma, start_addr,
1785 end_addr - start_addr, details);
1786 need_break = need_resched() ||
1787 need_lockbreak(details->i_mmap_lock);
1789 if (restart_addr >= end_addr) {
1790 /* We have now completed this vma: mark it so */
1791 vma->vm_truncate_count = details->truncate_count;
1795 /* Note restart_addr in vma's truncate_count field */
1796 vma->vm_truncate_count = restart_addr;
1801 spin_unlock(details->i_mmap_lock);
1803 spin_lock(details->i_mmap_lock);
1807 static inline void unmap_mapping_range_tree(struct prio_tree_root *root,
1808 struct zap_details *details)
1810 struct vm_area_struct *vma;
1811 struct prio_tree_iter iter;
1812 pgoff_t vba, vea, zba, zea;
1815 vma_prio_tree_foreach(vma, &iter, root,
1816 details->first_index, details->last_index) {
1817 /* Skip quickly over those we have already dealt with */
1818 if (vma->vm_truncate_count == details->truncate_count)
1821 vba = vma->vm_pgoff;
1822 vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1;
1823 /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */
1824 zba = details->first_index;
1827 zea = details->last_index;
1831 if (unmap_mapping_range_vma(vma,
1832 ((zba - vba) << PAGE_SHIFT) + vma->vm_start,
1833 ((zea - vba + 1) << PAGE_SHIFT) + vma->vm_start,
1839 static inline void unmap_mapping_range_list(struct list_head *head,
1840 struct zap_details *details)
1842 struct vm_area_struct *vma;
1845 * In nonlinear VMAs there is no correspondence between virtual address
1846 * offset and file offset. So we must perform an exhaustive search
1847 * across *all* the pages in each nonlinear VMA, not just the pages
1848 * whose virtual address lies outside the file truncation point.
1851 list_for_each_entry(vma, head, shared.vm_set.list) {
1852 /* Skip quickly over those we have already dealt with */
1853 if (vma->vm_truncate_count == details->truncate_count)
1855 details->nonlinear_vma = vma;
1856 if (unmap_mapping_range_vma(vma, vma->vm_start,
1857 vma->vm_end, details) < 0)
1863 * unmap_mapping_range - unmap the portion of all mmaps
1864 * in the specified address_space corresponding to the specified
1865 * page range in the underlying file.
1866 * @mapping: the address space containing mmaps to be unmapped.
1867 * @holebegin: byte in first page to unmap, relative to the start of
1868 * the underlying file. This will be rounded down to a PAGE_SIZE
1869 * boundary. Note that this is different from vmtruncate(), which
1870 * must keep the partial page. In contrast, we must get rid of
1872 * @holelen: size of prospective hole in bytes. This will be rounded
1873 * up to a PAGE_SIZE boundary. A holelen of zero truncates to the
1875 * @even_cows: 1 when truncating a file, unmap even private COWed pages;
1876 * but 0 when invalidating pagecache, don't throw away private data.
1878 void unmap_mapping_range(struct address_space *mapping,
1879 loff_t const holebegin, loff_t const holelen, int even_cows)
1881 struct zap_details details;
1882 pgoff_t hba = holebegin >> PAGE_SHIFT;
1883 pgoff_t hlen = (holelen + PAGE_SIZE - 1) >> PAGE_SHIFT;
1885 /* Check for overflow. */
1886 if (sizeof(holelen) > sizeof(hlen)) {
1888 (holebegin + holelen + PAGE_SIZE - 1) >> PAGE_SHIFT;
1889 if (holeend & ~(long long)ULONG_MAX)
1890 hlen = ULONG_MAX - hba + 1;
1893 details.check_mapping = even_cows? NULL: mapping;
1894 details.nonlinear_vma = NULL;
1895 details.first_index = hba;
1896 details.last_index = hba + hlen - 1;
1897 if (details.last_index < details.first_index)
1898 details.last_index = ULONG_MAX;
1899 details.i_mmap_lock = &mapping->i_mmap_lock;
1901 spin_lock(&mapping->i_mmap_lock);
1903 /* serialize i_size write against truncate_count write */
1905 /* Protect against page faults, and endless unmapping loops */
1906 mapping->truncate_count++;
1908 * For archs where spin_lock has inclusive semantics like ia64
1909 * this smp_mb() will prevent to read pagetable contents
1910 * before the truncate_count increment is visible to
1914 if (unlikely(is_restart_addr(mapping->truncate_count))) {
1915 if (mapping->truncate_count == 0)
1916 reset_vma_truncate_counts(mapping);
1917 mapping->truncate_count++;
1919 details.truncate_count = mapping->truncate_count;
1921 if (unlikely(!prio_tree_empty(&mapping->i_mmap)))
1922 unmap_mapping_range_tree(&mapping->i_mmap, &details);
1923 if (unlikely(!list_empty(&mapping->i_mmap_nonlinear)))
1924 unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details);
1925 spin_unlock(&mapping->i_mmap_lock);
1927 EXPORT_SYMBOL(unmap_mapping_range);
1930 * Handle all mappings that got truncated by a "truncate()"
1933 * NOTE! We have to be ready to update the memory sharing
1934 * between the file and the memory map for a potential last
1935 * incomplete page. Ugly, but necessary.
1937 int vmtruncate(struct inode * inode, loff_t offset)
1939 struct address_space *mapping = inode->i_mapping;
1940 unsigned long limit;
1942 if (inode->i_size < offset)
1945 * truncation of in-use swapfiles is disallowed - it would cause
1946 * subsequent swapout to scribble on the now-freed blocks.
1948 if (IS_SWAPFILE(inode))
1950 i_size_write(inode, offset);
1951 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
1952 truncate_inode_pages(mapping, offset);
1956 limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
1957 if (limit != RLIM_INFINITY && offset > limit)
1959 if (offset > inode->i_sb->s_maxbytes)
1961 i_size_write(inode, offset);
1964 if (inode->i_op && inode->i_op->truncate)
1965 inode->i_op->truncate(inode);
1968 send_sig(SIGXFSZ, current, 0);
1974 EXPORT_SYMBOL(vmtruncate);
1976 int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
1978 struct address_space *mapping = inode->i_mapping;
1981 * If the underlying filesystem is not going to provide
1982 * a way to truncate a range of blocks (punch a hole) -
1983 * we should return failure right now.
1985 if (!inode->i_op || !inode->i_op->truncate_range)
1988 mutex_lock(&inode->i_mutex);
1989 down_write(&inode->i_alloc_sem);
1990 unmap_mapping_range(mapping, offset, (end - offset), 1);
1991 truncate_inode_pages_range(mapping, offset, end);
1992 inode->i_op->truncate_range(inode, offset, end);
1993 up_write(&inode->i_alloc_sem);
1994 mutex_unlock(&inode->i_mutex);
1998 EXPORT_UNUSED_SYMBOL(vmtruncate_range); /* June 2006 */
2001 * Primitive swap readahead code. We simply read an aligned block of
2002 * (1 << page_cluster) entries in the swap area. This method is chosen
2003 * because it doesn't cost us any seek time. We also make sure to queue
2004 * the 'original' request together with the readahead ones...
2006 * This has been extended to use the NUMA policies from the mm triggering
2009 * Caller must hold down_read on the vma->vm_mm if vma is not NULL.
2011 void swapin_readahead(swp_entry_t entry, unsigned long addr,struct vm_area_struct *vma)
2014 struct vm_area_struct *next_vma = vma ? vma->vm_next : NULL;
2017 struct page *new_page;
2018 unsigned long offset;
2021 * Get the number of handles we should do readahead io to.
2023 num = valid_swaphandles(entry, &offset);
2024 for (i = 0; i < num; offset++, i++) {
2025 /* Ok, do the async read-ahead now */
2026 new_page = read_swap_cache_async(swp_entry(swp_type(entry),
2027 offset), vma, addr);
2030 page_cache_release(new_page);
2033 * Find the next applicable VMA for the NUMA policy.
2039 if (addr >= vma->vm_end) {
2041 next_vma = vma ? vma->vm_next : NULL;
2043 if (vma && addr < vma->vm_start)
2046 if (next_vma && addr >= next_vma->vm_start) {
2048 next_vma = vma->vm_next;
2053 lru_add_drain(); /* Push any new pages onto the LRU now */
2057 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2058 * but allow concurrent faults), and pte mapped but not yet locked.
2059 * We return with mmap_sem still held, but pte unmapped and unlocked.
2061 static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
2062 unsigned long address, pte_t *page_table, pmd_t *pmd,
2063 int write_access, pte_t orig_pte)
2069 int ret = VM_FAULT_MINOR;
2071 if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
2074 entry = pte_to_swp_entry(orig_pte);
2075 if (is_migration_entry(entry)) {
2076 migration_entry_wait(mm, pmd, address);
2079 delayacct_set_flag(DELAYACCT_PF_SWAPIN);
2080 page = lookup_swap_cache(entry);
2082 swapin_readahead(entry, address, vma);
2083 page = read_swap_cache_async(entry, vma, address);
2086 * Back out if somebody else faulted in this pte
2087 * while we released the pte lock.
2089 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
2090 if (likely(pte_same(*page_table, orig_pte)))
2092 delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
2096 /* Had to read the page from swap area: Major fault */
2097 ret = VM_FAULT_MAJOR;
2098 count_vm_event(PGMAJFAULT);
2102 if (!vx_rsspages_avail(mm, 1)) {
2107 delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
2108 mark_page_accessed(page);
2112 * Back out if somebody else already faulted in this pte.
2114 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
2115 if (unlikely(!pte_same(*page_table, orig_pte)))
2118 if (unlikely(!PageUptodate(page))) {
2119 ret = VM_FAULT_SIGBUS;
2123 /* The page isn't present yet, go ahead with the fault. */
2125 inc_mm_counter(mm, anon_rss);
2126 pte = mk_pte(page, vma->vm_page_prot);
2127 if (write_access && can_share_swap_page(page)) {
2128 pte = maybe_mkwrite(pte_mkdirty(pte), vma);
2132 flush_icache_page(vma, page);
2133 set_pte_at(mm, address, page_table, pte);
2134 page_add_anon_rmap(page, vma, address);
2138 remove_exclusive_swap_page(page);
2142 if (do_wp_page(mm, vma, address,
2143 page_table, pmd, ptl, pte) == VM_FAULT_OOM)
2148 /* No need to invalidate - it was non-present before */
2149 update_mmu_cache(vma, address, pte);
2150 lazy_mmu_prot_update(pte);
2152 pte_unmap_unlock(page_table, ptl);
2156 pte_unmap_unlock(page_table, ptl);
2158 page_cache_release(page);
2163 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2164 * but allow concurrent faults), and pte mapped but not yet locked.
2165 * We return with mmap_sem still held, but pte unmapped and unlocked.
2167 static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
2168 unsigned long address, pte_t *page_table, pmd_t *pmd,
2176 /* Allocate our own private page. */
2177 pte_unmap(page_table);
2179 if (!vx_rsspages_avail(mm, 1))
2181 if (unlikely(anon_vma_prepare(vma)))
2183 page = alloc_zeroed_user_highpage(vma, address);
2187 entry = mk_pte(page, vma->vm_page_prot);
2188 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
2190 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
2191 if (!pte_none(*page_table))
2193 inc_mm_counter(mm, anon_rss);
2194 lru_cache_add_active(page);
2195 page_add_new_anon_rmap(page, vma, address);
2197 /* Map the ZERO_PAGE - vm_page_prot is readonly */
2198 page = ZERO_PAGE(address);
2199 page_cache_get(page);
2200 entry = mk_pte(page, vma->vm_page_prot);
2202 ptl = pte_lockptr(mm, pmd);
2204 if (!pte_none(*page_table))
2206 inc_mm_counter(mm, file_rss);
2207 page_add_file_rmap(page);
2210 set_pte_at(mm, address, page_table, entry);
2212 /* No need to invalidate - it was non-present before */
2213 update_mmu_cache(vma, address, entry);
2214 lazy_mmu_prot_update(entry);
2216 pte_unmap_unlock(page_table, ptl);
2217 return VM_FAULT_MINOR;
2219 page_cache_release(page);
2222 return VM_FAULT_OOM;
2226 * do_no_page() tries to create a new page mapping. It aggressively
2227 * tries to share with existing pages, but makes a separate copy if
2228 * the "write_access" parameter is true in order to avoid the next
2231 * As this is called only for pages that do not currently exist, we
2232 * do not need to flush old virtual caches or the TLB.
2234 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2235 * but allow concurrent faults), and pte mapped but not yet locked.
2236 * We return with mmap_sem still held, but pte unmapped and unlocked.
2238 static int do_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
2239 unsigned long address, pte_t *page_table, pmd_t *pmd,
2243 struct page *new_page;
2244 struct address_space *mapping = NULL;
2246 unsigned int sequence = 0;
2247 int ret = VM_FAULT_MINOR;
2249 struct page *dirty_page = NULL;
2251 pte_unmap(page_table);
2252 BUG_ON(vma->vm_flags & VM_PFNMAP);
2255 mapping = vma->vm_file->f_mapping;
2256 sequence = mapping->truncate_count;
2257 smp_rmb(); /* serializes i_size against truncate_count */
2260 /* FIXME: is that check useful here? */
2261 if (!vx_rsspages_avail(mm, 1))
2262 return VM_FAULT_OOM;
2263 new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret);
2265 * No smp_rmb is needed here as long as there's a full
2266 * spin_lock/unlock sequence inside the ->nopage callback
2267 * (for the pagecache lookup) that acts as an implicit
2268 * smp_mb() and prevents the i_size read to happen
2269 * after the next truncate_count read.
2272 /* no page was available -- either SIGBUS or OOM */
2273 if (new_page == NOPAGE_SIGBUS)
2274 return VM_FAULT_SIGBUS;
2275 if (new_page == NOPAGE_OOM)
2276 return VM_FAULT_OOM;
2279 * Should we do an early C-O-W break?
2282 if (!(vma->vm_flags & VM_SHARED)) {
2285 if (unlikely(anon_vma_prepare(vma)))
2287 page = alloc_page_vma(GFP_HIGHUSER, vma, address);
2290 copy_user_highpage(page, new_page, address);
2291 page_cache_release(new_page);
2296 /* if the page will be shareable, see if the backing
2297 * address space wants to know that the page is about
2298 * to become writable */
2299 if (vma->vm_ops->page_mkwrite &&
2300 vma->vm_ops->page_mkwrite(vma, new_page) < 0
2302 page_cache_release(new_page);
2303 return VM_FAULT_SIGBUS;
2308 page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
2310 * For a file-backed vma, someone could have truncated or otherwise
2311 * invalidated this page. If unmap_mapping_range got called,
2312 * retry getting the page.
2314 if (mapping && unlikely(sequence != mapping->truncate_count)) {
2315 pte_unmap_unlock(page_table, ptl);
2316 page_cache_release(new_page);
2318 sequence = mapping->truncate_count;
2324 * This silly early PAGE_DIRTY setting removes a race
2325 * due to the bad i386 page protection. But it's valid
2326 * for other architectures too.
2328 * Note that if write_access is true, we either now have
2329 * an exclusive copy of the page, or this is a shared mapping,
2330 * so we can make it writable and dirty to avoid having to
2331 * handle that later.
2333 /* Only go through if we didn't race with anybody else... */
2334 if (pte_none(*page_table)) {
2335 flush_icache_page(vma, new_page);
2336 entry = mk_pte(new_page, vma->vm_page_prot);
2338 entry = maybe_mkwrite(pte_mkdirty(entry), vma);
2339 set_pte_at(mm, address, page_table, entry);
2341 inc_mm_counter(mm, anon_rss);
2342 lru_cache_add_active(new_page);
2343 page_add_new_anon_rmap(new_page, vma, address);
2345 inc_mm_counter(mm, file_rss);
2346 page_add_file_rmap(new_page);
2348 dirty_page = new_page;
2349 get_page(dirty_page);
2353 /* One of our sibling threads was faster, back out. */
2354 page_cache_release(new_page);
2358 /* no need to invalidate: a not-present page shouldn't be cached */
2359 update_mmu_cache(vma, address, entry);
2360 lazy_mmu_prot_update(entry);
2362 pte_unmap_unlock(page_table, ptl);
2364 set_page_dirty_balance(dirty_page);
2365 put_page(dirty_page);
2369 page_cache_release(new_page);
2370 return VM_FAULT_OOM;
2374 * Fault of a previously existing named mapping. Repopulate the pte
2375 * from the encoded file_pte if possible. This enables swappable
2378 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2379 * but allow concurrent faults), and pte mapped but not yet locked.
2380 * We return with mmap_sem still held, but pte unmapped and unlocked.
2382 static int do_file_page(struct mm_struct *mm, struct vm_area_struct *vma,
2383 unsigned long address, pte_t *page_table, pmd_t *pmd,
2384 int write_access, pte_t orig_pte)
2389 if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
2390 return VM_FAULT_MINOR;
2392 if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) {
2394 * Page table corrupted: show pte and kill process.
2396 print_bad_pte(vma, orig_pte, address);
2397 return VM_FAULT_OOM;
2399 /* We can then assume vm->vm_ops && vma->vm_ops->populate */
2401 pgoff = pte_to_pgoff(orig_pte);
2402 err = vma->vm_ops->populate(vma, address & PAGE_MASK, PAGE_SIZE,
2403 vma->vm_page_prot, pgoff, 0);
2405 return VM_FAULT_OOM;
2407 return VM_FAULT_SIGBUS;
2408 return VM_FAULT_MAJOR;
2412 * These routines also need to handle stuff like marking pages dirty
2413 * and/or accessed for architectures that don't do it in hardware (most
2414 * RISC architectures). The early dirtying is also good on the i386.
2416 * There is also a hook called "update_mmu_cache()" that architectures
2417 * with external mmu caches can use to update those (ie the Sparc or
2418 * PowerPC hashed page tables that act as extended TLBs).
2420 * We enter with non-exclusive mmap_sem (to exclude vma changes,
2421 * but allow concurrent faults), and pte mapped but not yet locked.
2422 * We return with mmap_sem still held, but pte unmapped and unlocked.
2424 static inline int handle_pte_fault(struct mm_struct *mm,
2425 struct vm_area_struct *vma, unsigned long address,
2426 pte_t *pte, pmd_t *pmd, int write_access)
2432 old_entry = entry = *pte;
2433 if (!pte_present(entry)) {
2434 if (pte_none(entry)) {
2435 if (!vma->vm_ops || !vma->vm_ops->nopage)
2436 return do_anonymous_page(mm, vma, address,
2437 pte, pmd, write_access);
2438 return do_no_page(mm, vma, address,
2439 pte, pmd, write_access);
2441 if (pte_file(entry))
2442 return do_file_page(mm, vma, address,
2443 pte, pmd, write_access, entry);
2444 return do_swap_page(mm, vma, address,
2445 pte, pmd, write_access, entry);
2448 ptl = pte_lockptr(mm, pmd);
2450 if (unlikely(!pte_same(*pte, entry)))
2453 if (!pte_write(entry))
2454 return do_wp_page(mm, vma, address,
2455 pte, pmd, ptl, entry);
2456 entry = pte_mkdirty(entry);
2458 entry = pte_mkyoung(entry);
2459 if (!pte_same(old_entry, entry)) {
2460 ptep_set_access_flags(vma, address, pte, entry, write_access);
2461 update_mmu_cache(vma, address, entry);
2462 lazy_mmu_prot_update(entry);
2465 * This is needed only for protection faults but the arch code
2466 * is not yet telling us if this is a protection fault or not.
2467 * This still avoids useless tlb flushes for .text page faults
2471 flush_tlb_page(vma, address);
2474 pte_unmap_unlock(pte, ptl);
2475 return VM_FAULT_MINOR;
2479 * By the time we get here, we already hold the mm semaphore
2481 int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
2482 unsigned long address, int write_access)
2489 __set_current_state(TASK_RUNNING);
2491 count_vm_event(PGFAULT);
2493 if (unlikely(is_vm_hugetlb_page(vma)))
2494 return hugetlb_fault(mm, vma, address, write_access);
2496 pgd = pgd_offset(mm, address);
2497 pud = pud_alloc(mm, pgd, address);
2499 return VM_FAULT_OOM;
2500 pmd = pmd_alloc(mm, pud, address);
2502 return VM_FAULT_OOM;
2503 pte = pte_alloc_map(mm, pmd, address);
2505 return VM_FAULT_OOM;
2507 return handle_pte_fault(mm, vma, address, pte, pmd, write_access);
2510 EXPORT_SYMBOL_GPL(__handle_mm_fault);
2512 #ifndef __PAGETABLE_PUD_FOLDED
2514 * Allocate page upper directory.
2515 * We've already handled the fast-path in-line.
2517 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
2519 pud_t *new = pud_alloc_one(mm, address);
2523 spin_lock(&mm->page_table_lock);
2524 if (pgd_present(*pgd)) /* Another has populated it */
2527 pgd_populate(mm, pgd, new);
2528 spin_unlock(&mm->page_table_lock);
2532 /* Workaround for gcc 2.96 */
2533 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
2537 #endif /* __PAGETABLE_PUD_FOLDED */
2539 #ifndef __PAGETABLE_PMD_FOLDED
2541 * Allocate page middle directory.
2542 * We've already handled the fast-path in-line.
2544 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
2546 pmd_t *new = pmd_alloc_one(mm, address);
2550 spin_lock(&mm->page_table_lock);
2551 #ifndef __ARCH_HAS_4LEVEL_HACK
2552 if (pud_present(*pud)) /* Another has populated it */
2555 pud_populate(mm, pud, new);
2557 if (pgd_present(*pud)) /* Another has populated it */
2560 pgd_populate(mm, pud, new);
2561 #endif /* __ARCH_HAS_4LEVEL_HACK */
2562 spin_unlock(&mm->page_table_lock);
2566 /* Workaround for gcc 2.96 */
2567 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
2571 #endif /* __PAGETABLE_PMD_FOLDED */
2573 int make_pages_present(unsigned long addr, unsigned long end)
2575 int ret, len, write;
2576 struct vm_area_struct * vma;
2578 vma = find_vma(current->mm, addr);
2581 write = (vma->vm_flags & VM_WRITE) != 0;
2582 BUG_ON(addr >= end);
2583 BUG_ON(end > vma->vm_end);
2584 len = (end+PAGE_SIZE-1)/PAGE_SIZE-addr/PAGE_SIZE;
2585 ret = get_user_pages(current, current->mm, addr,
2586 len, write, 0, NULL, NULL);
2589 return ret == len ? 0 : -1;
2593 * Map a vmalloc()-space virtual address to the physical page.
2595 struct page * vmalloc_to_page(void * vmalloc_addr)
2597 unsigned long addr = (unsigned long) vmalloc_addr;
2598 struct page *page = NULL;
2599 pgd_t *pgd = pgd_offset_k(addr);
2604 if (!pgd_none(*pgd)) {
2605 pud = pud_offset(pgd, addr);
2606 if (!pud_none(*pud)) {
2607 pmd = pmd_offset(pud, addr);
2608 if (!pmd_none(*pmd)) {
2609 ptep = pte_offset_map(pmd, addr);
2611 if (pte_present(pte))
2612 page = pte_page(pte);
2620 EXPORT_SYMBOL(vmalloc_to_page);
2623 * Map a vmalloc()-space virtual address to the physical page frame number.
2625 unsigned long vmalloc_to_pfn(void * vmalloc_addr)
2627 return page_to_pfn(vmalloc_to_page(vmalloc_addr));
2630 EXPORT_SYMBOL(vmalloc_to_pfn);
2632 #if !defined(__HAVE_ARCH_GATE_AREA)
2634 #if defined(AT_SYSINFO_EHDR)
2635 static struct vm_area_struct gate_vma;
2637 static int __init gate_vma_init(void)
2639 gate_vma.vm_mm = NULL;
2640 gate_vma.vm_start = FIXADDR_USER_START;
2641 gate_vma.vm_end = FIXADDR_USER_END;
2642 gate_vma.vm_page_prot = PAGE_READONLY;
2643 gate_vma.vm_flags = 0;
2646 __initcall(gate_vma_init);
2649 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
2651 #ifdef AT_SYSINFO_EHDR
2658 int in_gate_area_no_task(unsigned long addr)
2660 #ifdef AT_SYSINFO_EHDR
2661 if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
2667 #endif /* __HAVE_ARCH_GATE_AREA */