X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=mm%2Fmemory.c;h=119b7ccdf39b8ee542d3f4d695bff3c9d5322987;hb=0e950fa686d53a57ee6c47f477ecfc681670c6a9;hp=d5d1653d60a6be51a4ba74de53fd997d8b0bc94c;hpb=3b6748e2dd69906af3835db4dc9d1c8a3ee4c68c;p=safe%2Fjmp%2Flinux-2.6 diff --git a/mm/memory.c b/mm/memory.c index d5d1653..119b7cc 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -45,6 +45,7 @@ #include #include #include +#include #include #include #include @@ -55,7 +56,9 @@ #include #include #include +#include +#include #include #include #include @@ -106,6 +109,89 @@ static int __init disable_randmaps(char *s) } __setup("norandmaps", disable_randmaps); +unsigned long zero_pfn __read_mostly; +unsigned long highest_memmap_pfn __read_mostly; + +/* + * CONFIG_MMU architectures set up ZERO_PAGE in their paging_init() + */ +static int __init init_zero_pfn(void) +{ + zero_pfn = page_to_pfn(ZERO_PAGE(0)); + return 0; +} +core_initcall(init_zero_pfn); + + +#if defined(SPLIT_RSS_COUNTING) + +static void __sync_task_rss_stat(struct task_struct *task, struct mm_struct *mm) +{ + int i; + + for (i = 0; i < NR_MM_COUNTERS; i++) { + if (task->rss_stat.count[i]) { + add_mm_counter(mm, i, task->rss_stat.count[i]); + task->rss_stat.count[i] = 0; + } + } + task->rss_stat.events = 0; +} + +static void add_mm_counter_fast(struct mm_struct *mm, int member, int val) +{ + struct task_struct *task = current; + + if (likely(task->mm == mm)) + task->rss_stat.count[member] += val; + else + add_mm_counter(mm, member, val); +} +#define inc_mm_counter_fast(mm, member) add_mm_counter_fast(mm, member, 1) +#define dec_mm_counter_fast(mm, member) add_mm_counter_fast(mm, member, -1) + +/* sync counter once per 64 page faults */ +#define TASK_RSS_EVENTS_THRESH (64) +static void check_sync_rss_stat(struct task_struct *task) +{ + if (unlikely(task != current)) + return; + if (unlikely(task->rss_stat.events++ > TASK_RSS_EVENTS_THRESH)) + __sync_task_rss_stat(task, task->mm); +} + +unsigned long get_mm_counter(struct mm_struct *mm, int member) +{ + long val = 0; + + /* + * Don't use task->mm here...for avoiding to use task_get_mm().. + * The caller must guarantee task->mm is not invalid. + */ + val = atomic_long_read(&mm->rss_stat.count[member]); + /* + * counter is updated in asynchronous manner and may go to minus. + * But it's never be expected number for users. + */ + if (val < 0) + return 0; + return (unsigned long)val; +} + +void sync_mm_rss(struct task_struct *task, struct mm_struct *mm) +{ + __sync_task_rss_stat(task, mm); +} +#else + +#define inc_mm_counter_fast(mm, member) inc_mm_counter(mm, member) +#define dec_mm_counter_fast(mm, member) dec_mm_counter(mm, member) + +static void check_sync_rss_stat(struct task_struct *task) +{ +} + +#endif /* * If a p?d_bad entry is found while walking page tables, report @@ -135,11 +221,12 @@ void pmd_clear_bad(pmd_t *pmd) * Note: this doesn't free the actual pages themselves. That * has been handled earlier when unmapping all the memory regions. */ -static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd) +static void free_pte_range(struct mmu_gather *tlb, pmd_t *pmd, + unsigned long addr) { pgtable_t token = pmd_pgtable(*pmd); pmd_clear(pmd); - pte_free_tlb(tlb, token); + pte_free_tlb(tlb, token, addr); tlb->mm->nr_ptes--; } @@ -157,7 +244,7 @@ static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud, next = pmd_addr_end(addr, end); if (pmd_none_or_clear_bad(pmd)) continue; - free_pte_range(tlb, pmd); + free_pte_range(tlb, pmd, addr); } while (pmd++, addr = next, addr != end); start &= PUD_MASK; @@ -173,7 +260,7 @@ static inline void free_pmd_range(struct mmu_gather *tlb, pud_t *pud, pmd = pmd_offset(pud, start); pud_clear(pud); - pmd_free_tlb(tlb, pmd); + pmd_free_tlb(tlb, pmd, start); } static inline void free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, @@ -206,7 +293,7 @@ static inline void free_pud_range(struct mmu_gather *tlb, pgd_t *pgd, pud = pud_offset(pgd, start); pgd_clear(pgd); - pud_free_tlb(tlb, pud); + pud_free_tlb(tlb, pud, start); } /* @@ -282,9 +369,10 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long addr = vma->vm_start; /* - * Hide vma from rmap and vmtruncate before freeing pgtables + * Hide vma from rmap and truncate_pagecache before freeing + * pgtables */ - anon_vma_unlink(vma); + unlink_anon_vmas(vma); unlink_file_vma(vma); if (is_vm_hugetlb_page(vma)) { @@ -298,7 +386,7 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma, && !is_vm_hugetlb_page(next)) { vma = next; next = vma->vm_next; - anon_vma_unlink(vma); + unlink_anon_vmas(vma); unlink_file_vma(vma); } free_pgd_range(tlb, addr, vma->vm_end, @@ -360,12 +448,20 @@ int __pte_alloc_kernel(pmd_t *pmd, unsigned long address) return 0; } -static inline void add_mm_rss(struct mm_struct *mm, int file_rss, int anon_rss) +static inline void init_rss_vec(int *rss) { - if (file_rss) - add_mm_counter(mm, file_rss, file_rss); - if (anon_rss) - add_mm_counter(mm, anon_rss, anon_rss); + memset(rss, 0, sizeof(int) * NR_MM_COUNTERS); +} + +static inline void add_mm_rss_vec(struct mm_struct *mm, int *rss) +{ + int i; + + if (current->mm == mm) + sync_mm_rss(current, mm); + for (i = 0; i < NR_MM_COUNTERS; i++) + if (rss[i]) + add_mm_counter(mm, i, rss[i]); } /* @@ -414,12 +510,8 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr, "BUG: Bad page map in process %s pte:%08llx pmd:%08llx\n", current->comm, (long long)pte_val(pte), (long long)pmd_val(*pmd)); - if (page) { - printk(KERN_ALERT - "page:%p flags:%p count:%d mapcount:%d mapping:%p index:%lx\n", - page, (void *)page->flags, page_count(page), - page_mapcount(page), page->mapping, page->index); - } + if (page) + dump_page(page); printk(KERN_ALERT "addr:%p vm_flags:%08lx anon_vma:%p mapping:%p index:%lx\n", (void *)addr, vma->vm_flags, vma->anon_vma, mapping, index); @@ -441,6 +533,20 @@ static inline int is_cow_mapping(unsigned int flags) return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; } +#ifndef is_zero_pfn +static inline int is_zero_pfn(unsigned long pfn) +{ + return pfn == zero_pfn; +} +#endif + +#ifndef my_zero_pfn +static inline unsigned long my_zero_pfn(unsigned long addr) +{ + return zero_pfn; +} +#endif + /* * vm_normal_page -- This function gets the "struct page" associated with a pte. * @@ -496,7 +602,9 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, if (HAVE_PTE_SPECIAL) { if (likely(!pte_special(pte))) goto check_pfn; - if (!(vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))) + if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)) + return NULL; + if (!is_zero_pfn(pfn)) print_bad_pte(vma, addr, pte, NULL); return NULL; } @@ -518,6 +626,8 @@ struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, } } + if (is_zero_pfn(pfn)) + return NULL; check_pfn: if (unlikely(pfn > highest_memmap_pfn)) { print_bad_pte(vma, addr, pte, NULL); @@ -538,7 +648,7 @@ out: * covered by this vma. */ -static inline void +static inline unsigned long copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma, unsigned long addr, int *rss) @@ -552,7 +662,9 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, if (!pte_file(pte)) { swp_entry_t entry = pte_to_swp_entry(pte); - swap_duplicate(entry); + if (swap_duplicate(entry) < 0) + return entry.val; + /* make sure dst_mm is on swapoff's mmlist. */ if (unlikely(list_empty(&dst_mm->mmlist))) { spin_lock(&mmlist_lock); @@ -561,7 +673,9 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, &src_mm->mmlist); spin_unlock(&mmlist_lock); } - if (is_write_migration_entry(entry) && + if (likely(!non_swap_entry(entry))) + rss[MM_SWAPENTS]++; + else if (is_write_migration_entry(entry) && is_cow_mapping(vm_flags)) { /* * COW mappings require pages in both parent @@ -595,31 +709,40 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, page = vm_normal_page(vma, addr, pte); if (page) { get_page(page); - page_dup_rmap(page, vma, addr); - rss[!!PageAnon(page)]++; + page_dup_rmap(page); + if (PageAnon(page)) + rss[MM_ANONPAGES]++; + else + rss[MM_FILEPAGES]++; } out_set_pte: set_pte_at(dst_mm, addr, dst_pte, pte); + return 0; } static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma, unsigned long addr, unsigned long end) { + pte_t *orig_src_pte, *orig_dst_pte; pte_t *src_pte, *dst_pte; spinlock_t *src_ptl, *dst_ptl; int progress = 0; - int rss[2]; + int rss[NR_MM_COUNTERS]; + swp_entry_t entry = (swp_entry_t){0}; again: - rss[1] = rss[0] = 0; + init_rss_vec(rss); + dst_pte = pte_alloc_map_lock(dst_mm, dst_pmd, addr, &dst_ptl); if (!dst_pte) return -ENOMEM; src_pte = pte_offset_map_nested(src_pmd, addr); src_ptl = pte_lockptr(src_mm, src_pmd); spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); + orig_src_pte = src_pte; + orig_dst_pte = dst_pte; arch_enter_lazy_mmu_mode(); do { @@ -637,16 +760,25 @@ again: progress++; continue; } - copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, vma, addr, rss); + entry.val = copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, + vma, addr, rss); + if (entry.val) + break; progress += 8; } while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end); arch_leave_lazy_mmu_mode(); spin_unlock(src_ptl); - pte_unmap_nested(src_pte - 1); - add_mm_rss(dst_mm, rss[0], rss[1]); - pte_unmap_unlock(dst_pte - 1, dst_ptl); + pte_unmap_nested(orig_src_pte); + add_mm_rss_vec(dst_mm, rss); + pte_unmap_unlock(orig_dst_pte, dst_ptl); cond_resched(); + + if (entry.val) { + if (add_swap_count_continuation(entry, GFP_KERNEL) < 0) + return -ENOMEM; + progress = 0; + } if (addr != end) goto again; return 0; @@ -766,8 +898,9 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, struct mm_struct *mm = tlb->mm; pte_t *pte; spinlock_t *ptl; - int file_rss = 0; - int anon_rss = 0; + int rss[NR_MM_COUNTERS]; + + init_rss_vec(rss); pte = pte_offset_map_lock(mm, pmd, addr, &ptl); arch_enter_lazy_mmu_mode(); @@ -813,14 +946,14 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, set_pte_at(mm, addr, pte, pgoff_to_pte(page->index)); if (PageAnon(page)) - anon_rss--; + rss[MM_ANONPAGES]--; else { if (pte_dirty(ptent)) set_page_dirty(page); if (pte_young(ptent) && likely(!VM_SequentialReadHint(vma))) mark_page_accessed(page); - file_rss--; + rss[MM_FILEPAGES]--; } page_remove_rmap(page); if (unlikely(page_mapcount(page) < 0)) @@ -837,13 +970,18 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, if (pte_file(ptent)) { if (unlikely(!(vma->vm_flags & VM_NONLINEAR))) print_bad_pte(vma, addr, ptent, NULL); - } else if - (unlikely(!free_swap_and_cache(pte_to_swp_entry(ptent)))) - print_bad_pte(vma, addr, ptent, NULL); + } else { + swp_entry_t entry = pte_to_swp_entry(ptent); + + if (!non_swap_entry(entry)) + rss[MM_SWAPENTS]--; + if (unlikely(!free_swap_and_cache(entry))) + print_bad_pte(vma, addr, ptent, NULL); + } pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0)); - add_mm_rss(mm, file_rss, anon_rss); + add_mm_rss_vec(mm, rss); arch_leave_lazy_mmu_mode(); pte_unmap_unlock(pte - 1, ptl); @@ -906,6 +1044,7 @@ static unsigned long unmap_page_range(struct mmu_gather *tlb, details = NULL; BUG_ON(addr >= end); + mem_cgroup_uncharge_start(); tlb_start_vma(tlb, vma); pgd = pgd_offset(vma->vm_mm, addr); do { @@ -918,6 +1057,7 @@ static unsigned long unmap_page_range(struct mmu_gather *tlb, zap_work, details); } while (pgd++, addr = next, (addr != end && *zap_work > 0)); tlb_end_vma(tlb, vma); + mem_cgroup_uncharge_end(); return addr; } @@ -1087,8 +1227,17 @@ int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, } EXPORT_SYMBOL_GPL(zap_vma_ptes); -/* - * Do a quick page-table lookup for a single page. +/** + * follow_page - look up a page descriptor from a user-virtual address + * @vma: vm_area_struct mapping @address + * @address: virtual address to look up + * @flags: flags modifying lookup behaviour + * + * @flags can have FOLL_ flags set, defined in + * + * Returns the mapped (struct page *), %NULL if no mapping exists, or + * an error pointer if there is a mapping to something not represented + * by a page descriptor (see also vm_normal_page()). */ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, unsigned int flags) @@ -1141,9 +1290,14 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address, goto no_page; if ((flags & FOLL_WRITE) && !pte_write(pte)) goto unlock; + page = vm_normal_page(vma, address, pte); - if (unlikely(!page)) - goto bad_page; + if (unlikely(!page)) { + if ((flags & FOLL_DUMP) || + !is_zero_pfn(pte_pfn(pte))) + goto bad_page; + page = pte_page(pte); + } if (flags & FOLL_GET) get_page(page); @@ -1171,65 +1325,46 @@ no_page: pte_unmap_unlock(ptep, ptl); if (!pte_none(pte)) return page; - /* Fall through to ZERO_PAGE handling */ + no_page_table: /* * When core dumping an enormous anonymous area that nobody - * has touched so far, we don't want to allocate page tables. + * has touched so far, we don't want to allocate unnecessary pages or + * page tables. Return error instead of NULL to skip handle_mm_fault, + * then get_dump_page() will return NULL to leave a hole in the dump. + * But we can only make this optimization where a hole would surely + * be zero-filled if handle_mm_fault() actually did handle it. */ - if (flags & FOLL_ANON) { - page = ZERO_PAGE(0); - if (flags & FOLL_GET) - get_page(page); - BUG_ON(flags & FOLL_WRITE); - } + if ((flags & FOLL_DUMP) && + (!vma->vm_ops || !vma->vm_ops->fault)) + return ERR_PTR(-EFAULT); return page; } -/* Can we do the FOLL_ANON optimization? */ -static inline int use_zero_page(struct vm_area_struct *vma) -{ - /* - * We don't want to optimize FOLL_ANON for make_pages_present() - * when it tries to page in a VM_LOCKED region. As to VM_SHARED, - * we want to get the page from the page tables to make sure - * that we serialize and update with any other user of that - * mapping. - */ - if (vma->vm_flags & (VM_LOCKED | VM_SHARED)) - return 0; - /* - * And if we have a fault routine, it's not an anonymous region. - */ - return !vma->vm_ops || !vma->vm_ops->fault; -} - - - int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, int len, int flags, - struct page **pages, struct vm_area_struct **vmas) + unsigned long start, int nr_pages, unsigned int gup_flags, + struct page **pages, struct vm_area_struct **vmas) { int i; - unsigned int vm_flags = 0; - int write = !!(flags & GUP_FLAGS_WRITE); - int force = !!(flags & GUP_FLAGS_FORCE); - int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS); - int ignore_sigkill = !!(flags & GUP_FLAGS_IGNORE_SIGKILL); + unsigned long vm_flags; - if (len <= 0) + if (nr_pages <= 0) return 0; + + VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET)); + /* * Require read or write permissions. - * If 'force' is set, we only require the "MAY" flags. + * If FOLL_FORCE is set, we only require the "MAY" flags. */ - vm_flags = write ? (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); - vm_flags &= force ? (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); + vm_flags = (gup_flags & FOLL_WRITE) ? + (VM_WRITE | VM_MAYWRITE) : (VM_READ | VM_MAYREAD); + vm_flags &= (gup_flags & FOLL_FORCE) ? + (VM_MAYREAD | VM_MAYWRITE) : (VM_READ | VM_WRITE); i = 0; do { struct vm_area_struct *vma; - unsigned int foll_flags; vma = find_extend_vma(mm, start); if (!vma && in_gate_area(tsk, start)) { @@ -1241,7 +1376,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, pte_t *pte; /* user gate pages are read-only */ - if (!ignore && write) + if (gup_flags & FOLL_WRITE) return i ? : -EFAULT; if (pg > TASK_SIZE) pgd = pgd_offset_k(pg); @@ -1269,53 +1404,45 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, vmas[i] = gate_vma; i++; start += PAGE_SIZE; - len--; + nr_pages--; continue; } if (!vma || (vma->vm_flags & (VM_IO | VM_PFNMAP)) || - (!ignore && !(vm_flags & vma->vm_flags))) + !(vm_flags & vma->vm_flags)) return i ? : -EFAULT; if (is_vm_hugetlb_page(vma)) { i = follow_hugetlb_page(mm, vma, pages, vmas, - &start, &len, i, write); + &start, &nr_pages, i, gup_flags); continue; } - foll_flags = FOLL_TOUCH; - if (pages) - foll_flags |= FOLL_GET; - if (!write && use_zero_page(vma)) - foll_flags |= FOLL_ANON; - do { struct page *page; + unsigned int foll_flags = gup_flags; /* * If we have a pending SIGKILL, don't keep faulting - * pages and potentially allocating memory, unless - * current is handling munlock--e.g., on exit. In - * that case, we are not allocating memory. Rather, - * we're only unlocking already resident/mapped pages. + * pages and potentially allocating memory. */ - if (unlikely(!ignore_sigkill && - fatal_signal_pending(current))) + if (unlikely(fatal_signal_pending(current))) return i ? i : -ERESTARTSYS; - if (write) - foll_flags |= FOLL_WRITE; - cond_resched(); while (!(page = follow_page(vma, start, foll_flags))) { int ret; + ret = handle_mm_fault(mm, vma, start, - foll_flags & FOLL_WRITE); + (foll_flags & FOLL_WRITE) ? + FAULT_FLAG_WRITE : 0); + if (ret & VM_FAULT_ERROR) { if (ret & VM_FAULT_OOM) return i ? i : -ENOMEM; - else if (ret & VM_FAULT_SIGBUS) + if (ret & + (VM_FAULT_HWPOISON|VM_FAULT_SIGBUS)) return i ? i : -EFAULT; BUG(); } @@ -1354,9 +1481,9 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, vmas[i] = vma; i++; start += PAGE_SIZE; - len--; - } while (len && start < vma->vm_end); - } while (len); + nr_pages--; + } while (nr_pages && start < vma->vm_end); + } while (nr_pages); return i; } @@ -1365,7 +1492,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, * @tsk: task_struct of target task * @mm: mm_struct of target mm * @start: starting user address - * @len: number of pages from start to pin + * @nr_pages: number of pages from start to pin * @write: whether pages will be written to by the caller * @force: whether to force write access even if user mapping is * readonly. This will result in the page being COWed even @@ -1377,7 +1504,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, * Or NULL if the caller does not require them. * * Returns number of pages pinned. This may be fewer than the number - * requested. If len is 0 or negative, returns 0. If no pages + * requested. If nr_pages is 0 or negative, returns 0. If no pages * were pinned, returns -errno. Each page returned must be released * with a put_page() call when it is finished with. vmas will only * remain valid while mmap_sem is held. @@ -1411,23 +1538,50 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, * See also get_user_pages_fast, for performance critical applications. */ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, - unsigned long start, int len, int write, int force, + unsigned long start, int nr_pages, int write, int force, struct page **pages, struct vm_area_struct **vmas) { - int flags = 0; + int flags = FOLL_TOUCH; + if (pages) + flags |= FOLL_GET; if (write) - flags |= GUP_FLAGS_WRITE; + flags |= FOLL_WRITE; if (force) - flags |= GUP_FLAGS_FORCE; + flags |= FOLL_FORCE; - return __get_user_pages(tsk, mm, - start, len, flags, - pages, vmas); + return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas); } - EXPORT_SYMBOL(get_user_pages); +/** + * get_dump_page() - pin user page in memory while writing it to core dump + * @addr: user address + * + * Returns struct page pointer of user page pinned for dump, + * to be freed afterwards by page_cache_release() or put_page(). + * + * Returns NULL on any kind of failure - a hole must then be inserted into + * the corefile, to preserve alignment with its headers; and also returns + * NULL wherever the ZERO_PAGE, or an anonymous pte_none, has been found - + * allowing a hole to be left in the corefile to save diskspace. + * + * Called without mmap_sem, but after all other threads have been killed. + */ +#ifdef CONFIG_ELF_CORE +struct page *get_dump_page(unsigned long addr) +{ + struct vm_area_struct *vma; + struct page *page; + + if (__get_user_pages(current, current->mm, addr, 1, + FOLL_FORCE | FOLL_DUMP | FOLL_GET, &page, &vma) < 1) + return NULL; + flush_cache_page(vma, addr, page_to_pfn(page)); + return page; +} +#endif /* CONFIG_ELF_CORE */ + pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl) { @@ -1470,7 +1624,7 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr, /* Ok, finally just insert the thing.. */ get_page(page); - inc_mm_counter(mm, file_rss); + inc_mm_counter_fast(mm, MM_FILEPAGES); page_add_file_rmap(page); set_pte_at(mm, addr, pte, mk_pte(page, prot)); @@ -1536,7 +1690,7 @@ static int insert_pfn(struct vm_area_struct *vma, unsigned long addr, /* Ok, finally just insert the thing.. */ entry = pte_mkspecial(pfn_pte(pfn, prot)); set_pte_at(mm, addr, pte, entry); - update_mmu_cache(vma, addr, entry); /* XXX: why not for insert_page? */ + update_mmu_cache(vma, addr, pte); /* XXX: why not for insert_page? */ retval = 0; out_unlock: @@ -1605,7 +1759,8 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr, * If we don't have pte special, then we have to use the pfn_valid() * based VM_MIXEDMAP scheme (see vm_normal_page), and thus we *must* * refcount the page if pfn_valid is true (hence insert_page rather - * than insert_pfn). + * than insert_pfn). If a zero_pfn were inserted into a VM_MIXEDMAP + * without pte special, it would there be refcounted as a normal page. */ if (!HAVE_PTE_SPECIAL && pfn_valid(pfn)) { struct page *page; @@ -1780,10 +1935,10 @@ static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd, token = pmd_pgtable(*pmd); do { - err = fn(pte, token, addr, data); + err = fn(pte++, token, addr, data); if (err) break; - } while (pte++, addr += PAGE_SIZE, addr != end); + } while (addr += PAGE_SIZE, addr != end); arch_leave_lazy_mmu_mode(); @@ -1971,7 +2126,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, * Take out anonymous pages first, anonymous shared vmas are * not dirty accountable. */ - if (PageAnon(old_page)) { + if (PageAnon(old_page) && !PageKsm(old_page)) { if (!trylock_page(old_page)) { page_cache_get(old_page); pte_unmap_unlock(page_table, ptl); @@ -1986,6 +2141,13 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, page_cache_release(old_page); } reuse = reuse_swap_page(old_page); + if (reuse) + /* + * The page is all ours. Move it to our anon_vma so + * the rmap code will not search our parent or siblings. + * Protected against the rmap code by the page lock. + */ + page_move_anon_rmap(old_page, vma, address); unlock_page(old_page); } else if (unlikely((vma->vm_flags & (VM_WRITE|VM_SHARED)) == (VM_WRITE|VM_SHARED))) { @@ -2058,7 +2220,7 @@ reuse: entry = pte_mkyoung(orig_pte); entry = maybe_mkwrite(pte_mkdirty(entry), vma); if (ptep_set_access_flags(vma, address, page_table, entry,1)) - update_mmu_cache(vma, address, entry); + update_mmu_cache(vma, address, page_table); ret |= VM_FAULT_WRITE; goto unlock; } @@ -2072,10 +2234,19 @@ gotten: if (unlikely(anon_vma_prepare(vma))) goto oom; - VM_BUG_ON(old_page == ZERO_PAGE(0)); - new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); - if (!new_page) - goto oom; + + if (is_zero_pfn(pte_pfn(orig_pte))) { + new_page = alloc_zeroed_user_highpage_movable(vma, address); + if (!new_page) + goto oom; + } else { + new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); + if (!new_page) + goto oom; + cow_user_page(new_page, old_page, address, vma); + } + __SetPageUptodate(new_page); + /* * Don't let another task, with possibly unlocked vma, * keep the mlocked page. @@ -2085,8 +2256,6 @@ gotten: clear_page_mlock(old_page); unlock_page(old_page); } - cow_user_page(new_page, old_page, address, vma); - __SetPageUptodate(new_page); if (mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL)) goto oom_free_new; @@ -2098,11 +2267,11 @@ gotten: if (likely(pte_same(*page_table, orig_pte))) { if (old_page) { if (!PageAnon(old_page)) { - dec_mm_counter(mm, file_rss); - inc_mm_counter(mm, anon_rss); + dec_mm_counter_fast(mm, MM_FILEPAGES); + inc_mm_counter_fast(mm, MM_ANONPAGES); } } else - inc_mm_counter(mm, anon_rss); + inc_mm_counter_fast(mm, MM_ANONPAGES); flush_cache_page(vma, address, pte_pfn(orig_pte)); entry = mk_pte(new_page, vma->vm_page_prot); entry = maybe_mkwrite(pte_mkdirty(entry), vma); @@ -2112,10 +2281,15 @@ gotten: * seen in the presence of one thread doing SMC and another * thread doing COW. */ - ptep_clear_flush_notify(vma, address, page_table); + ptep_clear_flush(vma, address, page_table); page_add_new_anon_rmap(new_page, vma, address); - set_pte_at(mm, address, page_table, entry); - update_mmu_cache(vma, address, entry); + /* + * We call the notify macro here because, when using secondary + * mmu page tables (such as kvm shadow page tables), we want the + * new page to be mapped directly into the secondary page table. + */ + set_pte_at_notify(mm, address, page_table, entry); + update_mmu_cache(vma, address, page_table); if (old_page) { /* * Only after switching the pte to the new page may @@ -2357,7 +2531,7 @@ restart: * @mapping: the address space containing mmaps to be unmapped. * @holebegin: byte in first page to unmap, relative to the start of * the underlying file. This will be rounded down to a PAGE_SIZE - * boundary. Note that this is different from vmtruncate(), which + * boundary. Note that this is different from truncate_pagecache(), which * must keep the partial page. In contrast, we must get rid of * partial pages. * @holelen: size of prospective hole in bytes. This will be rounded @@ -2408,63 +2582,6 @@ void unmap_mapping_range(struct address_space *mapping, } EXPORT_SYMBOL(unmap_mapping_range); -/** - * vmtruncate - unmap mappings "freed" by truncate() syscall - * @inode: inode of the file used - * @offset: file offset to start truncating - * - * NOTE! We have to be ready to update the memory sharing - * between the file and the memory map for a potential last - * incomplete page. Ugly, but necessary. - */ -int vmtruncate(struct inode * inode, loff_t offset) -{ - if (inode->i_size < offset) { - unsigned long limit; - - limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; - if (limit != RLIM_INFINITY && offset > limit) - goto out_sig; - if (offset > inode->i_sb->s_maxbytes) - goto out_big; - i_size_write(inode, offset); - } else { - struct address_space *mapping = inode->i_mapping; - - /* - * truncation of in-use swapfiles is disallowed - it would - * cause subsequent swapout to scribble on the now-freed - * blocks. - */ - if (IS_SWAPFILE(inode)) - return -ETXTBSY; - i_size_write(inode, offset); - - /* - * unmap_mapping_range is called twice, first simply for - * efficiency so that truncate_inode_pages does fewer - * single-page unmaps. However after this first call, and - * before truncate_inode_pages finishes, it is possible for - * private pages to be COWed, which remain after - * truncate_inode_pages finishes, hence the second - * unmap_mapping_range call must be made for correctness. - */ - unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); - truncate_inode_pages(mapping, offset); - unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); - } - - if (inode->i_op->truncate) - inode->i_op->truncate(inode); - return 0; - -out_sig: - send_sig(SIGXFSZ, current, 0); -out_big: - return -EFBIG; -} -EXPORT_SYMBOL(vmtruncate); - int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end) { struct address_space *mapping = inode->i_mapping; @@ -2496,7 +2613,7 @@ int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end) */ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *page_table, pmd_t *pmd, - int write_access, pte_t orig_pte) + unsigned int flags, pte_t orig_pte) { spinlock_t *ptl; struct page *page; @@ -2509,14 +2626,21 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, goto out; entry = pte_to_swp_entry(orig_pte); - if (is_migration_entry(entry)) { - migration_entry_wait(mm, pmd, address); + if (unlikely(non_swap_entry(entry))) { + if (is_migration_entry(entry)) { + migration_entry_wait(mm, pmd, address); + } else if (is_hwpoison_entry(entry)) { + ret = VM_FAULT_HWPOISON; + } else { + print_bad_pte(vma, address, orig_pte, NULL); + ret = VM_FAULT_SIGBUS; + } goto out; } delayacct_set_flag(DELAYACCT_PF_SWAPIN); page = lookup_swap_cache(entry); if (!page) { - grab_swap_token(); /* Contend for token _before_ read-in */ + grab_swap_token(mm); /* Contend for token _before_ read-in */ page = swapin_readahead(entry, GFP_HIGHUSER_MOVABLE, vma, address); if (!page) { @@ -2534,11 +2658,25 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, /* Had to read the page from swap area: Major fault */ ret = VM_FAULT_MAJOR; count_vm_event(PGMAJFAULT); + } else if (PageHWPoison(page)) { + /* + * hwpoisoned dirty swapcache pages are kept for killing + * owner processes (which may be unknown at hwpoison time) + */ + ret = VM_FAULT_HWPOISON; + delayacct_clear_flag(DELAYACCT_PF_SWAPIN); + goto out_release; } lock_page(page); delayacct_clear_flag(DELAYACCT_PF_SWAPIN); + page = ksm_might_need_to_copy(page, vma, address); + if (!page) { + ret = VM_FAULT_OOM; + goto out; + } + if (mem_cgroup_try_charge_swapin(mm, page, GFP_KERNEL, &ptr)) { ret = VM_FAULT_OOM; goto out_page; @@ -2570,11 +2708,12 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, * discarded at swap_free(). */ - inc_mm_counter(mm, anon_rss); + inc_mm_counter_fast(mm, MM_ANONPAGES); + dec_mm_counter_fast(mm, MM_SWAPENTS); pte = mk_pte(page, vma->vm_page_prot); - if (write_access && reuse_swap_page(page)) { + if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) { pte = maybe_mkwrite(pte_mkdirty(pte), vma); - write_access = 0; + flags &= ~FAULT_FLAG_WRITE; } flush_icache_page(vma, page); set_pte_at(mm, address, page_table, pte); @@ -2587,7 +2726,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, try_to_free_swap(page); unlock_page(page); - if (write_access) { + if (flags & FAULT_FLAG_WRITE) { ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte); if (ret & VM_FAULT_ERROR) ret &= VM_FAULT_ERROR; @@ -2595,7 +2734,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, } /* No need to invalidate - it was non-present before */ - update_mmu_cache(vma, address, pte); + update_mmu_cache(vma, address, page_table); unlock: pte_unmap_unlock(page_table, ptl); out: @@ -2605,6 +2744,7 @@ out_nomap: pte_unmap_unlock(page_table, ptl); out_page: unlock_page(page); +out_release: page_cache_release(page); return ret; } @@ -2616,12 +2756,22 @@ out_page: */ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *page_table, pmd_t *pmd, - int write_access) + unsigned int flags) { struct page *page; spinlock_t *ptl; pte_t entry; + if (!(flags & FAULT_FLAG_WRITE)) { + entry = pte_mkspecial(pfn_pte(my_zero_pfn(address), + vma->vm_page_prot)); + ptl = pte_lockptr(mm, pmd); + spin_lock(ptl); + if (!pte_none(*page_table)) + goto unlock; + goto setpte; + } + /* Allocate our own private page. */ pte_unmap(page_table); @@ -2636,17 +2786,20 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, goto oom_free_page; entry = mk_pte(page, vma->vm_page_prot); - entry = maybe_mkwrite(pte_mkdirty(entry), vma); + if (vma->vm_flags & VM_WRITE) + entry = pte_mkwrite(pte_mkdirty(entry)); page_table = pte_offset_map_lock(mm, pmd, address, &ptl); if (!pte_none(*page_table)) goto release; - inc_mm_counter(mm, anon_rss); + + inc_mm_counter_fast(mm, MM_ANONPAGES); page_add_new_anon_rmap(page, vma, address); +setpte: set_pte_at(mm, address, page_table, entry); /* No need to invalidate - it was non-present before */ - update_mmu_cache(vma, address, entry); + update_mmu_cache(vma, address, page_table); unlock: pte_unmap_unlock(page_table, ptl); return 0; @@ -2697,6 +2850,12 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE))) return ret; + if (unlikely(PageHWPoison(vmf.page))) { + if (ret & VM_FAULT_LOCKED) + unlock_page(vmf.page); + return VM_FAULT_HWPOISON; + } + /* * For consistency in subsequent calls, make the faulted page always * locked. @@ -2776,7 +2935,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, * due to the bad i386 page protection. But it's valid * for other architectures too. * - * Note that if write_access is true, we either now have + * Note that if FAULT_FLAG_WRITE is set, we either now have * an exclusive copy of the page, or this is a shared mapping, * so we can make it writable and dirty to avoid having to * handle that later. @@ -2788,10 +2947,10 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (flags & FAULT_FLAG_WRITE) entry = maybe_mkwrite(pte_mkdirty(entry), vma); if (anon) { - inc_mm_counter(mm, anon_rss); + inc_mm_counter_fast(mm, MM_ANONPAGES); page_add_new_anon_rmap(page, vma, address); } else { - inc_mm_counter(mm, file_rss); + inc_mm_counter_fast(mm, MM_FILEPAGES); page_add_file_rmap(page); if (flags & FAULT_FLAG_WRITE) { dirty_page = page; @@ -2801,7 +2960,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma, set_pte_at(mm, address, page_table, entry); /* no need to invalidate: a not-present page won't be cached */ - update_mmu_cache(vma, address, entry); + update_mmu_cache(vma, address, page_table); } else { if (charged) mem_cgroup_uncharge_page(page); @@ -2847,11 +3006,10 @@ unwritable_page: static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *page_table, pmd_t *pmd, - int write_access, pte_t orig_pte) + unsigned int flags, pte_t orig_pte) { pgoff_t pgoff = (((address & PAGE_MASK) - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; - unsigned int flags = (write_access ? FAULT_FLAG_WRITE : 0); pte_unmap(page_table); return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte); @@ -2868,12 +3026,12 @@ static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma, */ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *page_table, pmd_t *pmd, - int write_access, pte_t orig_pte) + unsigned int flags, pte_t orig_pte) { - unsigned int flags = FAULT_FLAG_NONLINEAR | - (write_access ? FAULT_FLAG_WRITE : 0); pgoff_t pgoff; + flags |= FAULT_FLAG_NONLINEAR; + if (!pte_unmap_same(mm, pmd, page_table, orig_pte)) return 0; @@ -2882,7 +3040,7 @@ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma, * Page table corrupted: show pte and kill process. */ print_bad_pte(vma, address, orig_pte, NULL); - return VM_FAULT_OOM; + return VM_FAULT_SIGBUS; } pgoff = pte_to_pgoff(orig_pte); @@ -2904,7 +3062,7 @@ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma, */ static inline int handle_pte_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, - pte_t *pte, pmd_t *pmd, int write_access) + pte_t *pte, pmd_t *pmd, unsigned int flags) { pte_t entry; spinlock_t *ptl; @@ -2915,31 +3073,31 @@ static inline int handle_pte_fault(struct mm_struct *mm, if (vma->vm_ops) { if (likely(vma->vm_ops->fault)) return do_linear_fault(mm, vma, address, - pte, pmd, write_access, entry); + pte, pmd, flags, entry); } return do_anonymous_page(mm, vma, address, - pte, pmd, write_access); + pte, pmd, flags); } if (pte_file(entry)) return do_nonlinear_fault(mm, vma, address, - pte, pmd, write_access, entry); + pte, pmd, flags, entry); return do_swap_page(mm, vma, address, - pte, pmd, write_access, entry); + pte, pmd, flags, entry); } ptl = pte_lockptr(mm, pmd); spin_lock(ptl); if (unlikely(!pte_same(*pte, entry))) goto unlock; - if (write_access) { + if (flags & FAULT_FLAG_WRITE) { if (!pte_write(entry)) return do_wp_page(mm, vma, address, pte, pmd, ptl, entry); entry = pte_mkdirty(entry); } entry = pte_mkyoung(entry); - if (ptep_set_access_flags(vma, address, pte, entry, write_access)) { - update_mmu_cache(vma, address, entry); + if (ptep_set_access_flags(vma, address, pte, entry, flags & FAULT_FLAG_WRITE)) { + update_mmu_cache(vma, address, pte); } else { /* * This is needed only for protection faults but the arch code @@ -2947,7 +3105,7 @@ static inline int handle_pte_fault(struct mm_struct *mm, * This still avoids useless tlb flushes for .text page faults * with threads. */ - if (write_access) + if (flags & FAULT_FLAG_WRITE) flush_tlb_page(vma, address); } unlock: @@ -2959,7 +3117,7 @@ unlock: * By the time we get here, we already hold the mm semaphore */ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long address, int write_access) + unsigned long address, unsigned int flags) { pgd_t *pgd; pud_t *pud; @@ -2970,8 +3128,11 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, count_vm_event(PGFAULT); + /* do counter updates before entering really critical section. */ + check_sync_rss_stat(current); + if (unlikely(is_vm_hugetlb_page(vma))) - return hugetlb_fault(mm, vma, address, write_access); + return hugetlb_fault(mm, vma, address, flags); pgd = pgd_offset(mm, address); pud = pud_alloc(mm, pgd, address); @@ -2984,7 +3145,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, if (!pte) return VM_FAULT_OOM; - return handle_pte_fault(mm, vma, address, pte, pmd, write_access); + return handle_pte_fault(mm, vma, address, pte, pmd, flags); } #ifndef __PAGETABLE_PUD_FOLDED