diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 162 |
1 files changed, 70 insertions, 92 deletions
diff --git a/mm/memory.c b/mm/memory.c index bcc4b0727a63..8f1de811a1dc 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -433,35 +433,39 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma, } } -int __pte_alloc(struct mm_struct *mm, pmd_t *pmd) +void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte) { - spinlock_t *ptl; - pgtable_t new = pte_alloc_one(mm); - if (!new) - return -ENOMEM; + spinlock_t *ptl = pmd_lock(mm, pmd); - /* - * Ensure all pte setup (eg. pte page lock and page clearing) are - * visible before the pte is made visible to other CPUs by being - * put into page tables. - * - * The other side of the story is the pointer chasing in the page - * table walking code (when walking the page table without locking; - * ie. most of the time). Fortunately, these data accesses consist - * of a chain of data-dependent loads, meaning most CPUs (alpha - * being the notable exception) will already guarantee loads are - * seen in-order. See the alpha page table accessors for the - * smp_rmb() barriers in page table walking code. - */ - smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */ - - ptl = pmd_lock(mm, pmd); if (likely(pmd_none(*pmd))) { /* Has another populated it ? */ mm_inc_nr_ptes(mm); - pmd_populate(mm, pmd, new); - new = NULL; + /* + * Ensure all pte setup (eg. pte page lock and page clearing) are + * visible before the pte is made visible to other CPUs by being + * put into page tables. + * + * The other side of the story is the pointer chasing in the page + * table walking code (when walking the page table without locking; + * ie. most of the time). Fortunately, these data accesses consist + * of a chain of data-dependent loads, meaning most CPUs (alpha + * being the notable exception) will already guarantee loads are + * seen in-order. See the alpha page table accessors for the + * smp_rmb() barriers in page table walking code. + */ + smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */ + pmd_populate(mm, pmd, *pte); + *pte = NULL; } spin_unlock(ptl); +} + +int __pte_alloc(struct mm_struct *mm, pmd_t *pmd) +{ + pgtable_t new = pte_alloc_one(mm); + if (!new) + return -ENOMEM; + + pmd_install(mm, pmd, &new); if (new) pte_free(mm, new); return 0; @@ -473,10 +477,9 @@ int __pte_alloc_kernel(pmd_t *pmd) if (!new) return -ENOMEM; - smp_wmb(); /* See comment in __pte_alloc */ - spin_lock(&init_mm.page_table_lock); if (likely(pmd_none(*pmd))) { /* Has another populated it ? */ + smp_wmb(); /* See comment in pmd_install() */ pmd_populate_kernel(&init_mm, pmd, new); new = NULL; } @@ -1333,16 +1336,8 @@ again: struct page *page; page = vm_normal_page(vma, addr, ptent); - if (unlikely(details) && page) { - /* - * unmap_shared_mapping_pages() wants to - * invalidate cache without truncating: - * unmap shared but keep private pages. - */ - if (details->check_mapping && - details->check_mapping != page_rmapping(page)) - continue; - } + if (unlikely(zap_skip_check_mapping(details, page))) + continue; ptent = ptep_get_and_clear_full(mm, addr, pte, tlb->fullmm); tlb_remove_tlb_entry(tlb, pte, addr); @@ -1375,17 +1370,8 @@ again: is_device_exclusive_entry(entry)) { struct page *page = pfn_swap_entry_to_page(entry); - if (unlikely(details && details->check_mapping)) { - /* - * unmap_shared_mapping_pages() wants to - * invalidate cache without truncating: - * unmap shared but keep private pages. - */ - if (details->check_mapping != - page_rmapping(page)) - continue; - } - + if (unlikely(zap_skip_check_mapping(details, page))) + continue; pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); rss[mm_counter(page)]--; @@ -2724,19 +2710,19 @@ EXPORT_SYMBOL_GPL(apply_to_existing_page_range); * proceeding (but do_wp_page is only called after already making such a check; * and do_anonymous_page can safely check later on). */ -static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd, - pte_t *page_table, pte_t orig_pte) +static inline int pte_unmap_same(struct vm_fault *vmf) { int same = 1; #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPTION) if (sizeof(pte_t) > sizeof(unsigned long)) { - spinlock_t *ptl = pte_lockptr(mm, pmd); + spinlock_t *ptl = pte_lockptr(vmf->vma->vm_mm, vmf->pmd); spin_lock(ptl); - same = pte_same(*page_table, orig_pte); + same = pte_same(*vmf->pte, vmf->orig_pte); spin_unlock(ptl); } #endif - pte_unmap(page_table); + pte_unmap(vmf->pte); + vmf->pte = NULL; return same; } @@ -3321,20 +3307,20 @@ static void unmap_mapping_range_vma(struct vm_area_struct *vma, } static inline void unmap_mapping_range_tree(struct rb_root_cached *root, + pgoff_t first_index, + pgoff_t last_index, struct zap_details *details) { struct vm_area_struct *vma; pgoff_t vba, vea, zba, zea; - vma_interval_tree_foreach(vma, root, - details->first_index, details->last_index) { - + vma_interval_tree_foreach(vma, root, first_index, last_index) { vba = vma->vm_pgoff; vea = vba + vma_pages(vma) - 1; - zba = details->first_index; + zba = first_index; if (zba < vba) zba = vba; - zea = details->last_index; + zea = last_index; if (zea > vea) zea = vea; @@ -3360,18 +3346,22 @@ void unmap_mapping_page(struct page *page) { struct address_space *mapping = page->mapping; struct zap_details details = { }; + pgoff_t first_index; + pgoff_t last_index; VM_BUG_ON(!PageLocked(page)); VM_BUG_ON(PageTail(page)); - details.check_mapping = mapping; - details.first_index = page->index; - details.last_index = page->index + thp_nr_pages(page) - 1; + first_index = page->index; + last_index = page->index + thp_nr_pages(page) - 1; + + details.zap_mapping = mapping; details.single_page = page; i_mmap_lock_write(mapping); if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))) - unmap_mapping_range_tree(&mapping->i_mmap, &details); + unmap_mapping_range_tree(&mapping->i_mmap, first_index, + last_index, &details); i_mmap_unlock_write(mapping); } @@ -3391,16 +3381,17 @@ void unmap_mapping_pages(struct address_space *mapping, pgoff_t start, pgoff_t nr, bool even_cows) { struct zap_details details = { }; + pgoff_t first_index = start; + pgoff_t last_index = start + nr - 1; - details.check_mapping = even_cows ? NULL : mapping; - details.first_index = start; - details.last_index = start + nr - 1; - if (details.last_index < details.first_index) - details.last_index = ULONG_MAX; + details.zap_mapping = even_cows ? NULL : mapping; + if (last_index < first_index) + last_index = ULONG_MAX; i_mmap_lock_write(mapping); if (unlikely(!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root))) - unmap_mapping_range_tree(&mapping->i_mmap, &details); + unmap_mapping_range_tree(&mapping->i_mmap, first_index, + last_index, &details); i_mmap_unlock_write(mapping); } EXPORT_SYMBOL_GPL(unmap_mapping_pages); @@ -3488,7 +3479,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) vm_fault_t ret = 0; void *shadow = NULL; - if (!pte_unmap_same(vma->vm_mm, vmf->pmd, vmf->pte, vmf->orig_pte)) + if (!pte_unmap_same(vmf)) goto out; entry = pte_to_swp_entry(vmf->orig_pte); @@ -3853,7 +3844,6 @@ static vm_fault_t __do_fault(struct vm_fault *vmf) vmf->prealloc_pte = pte_alloc_one(vma->vm_mm); if (!vmf->prealloc_pte) return VM_FAULT_OOM; - smp_wmb(); /* See comment in __pte_alloc() */ } ret = vma->vm_ops->fault(vmf); @@ -3924,7 +3914,6 @@ vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page) vmf->prealloc_pte = pte_alloc_one(vma->vm_mm); if (!vmf->prealloc_pte) return VM_FAULT_OOM; - smp_wmb(); /* See comment in __pte_alloc() */ } vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); @@ -4037,17 +4026,10 @@ vm_fault_t finish_fault(struct vm_fault *vmf) return ret; } - if (vmf->prealloc_pte) { - vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); - if (likely(pmd_none(*vmf->pmd))) { - mm_inc_nr_ptes(vma->vm_mm); - pmd_populate(vma->vm_mm, vmf->pmd, vmf->prealloc_pte); - vmf->prealloc_pte = NULL; - } - spin_unlock(vmf->ptl); - } else if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd))) { + if (vmf->prealloc_pte) + pmd_install(vma->vm_mm, vmf->pmd, &vmf->prealloc_pte); + else if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd))) return VM_FAULT_OOM; - } } /* See comment in handle_pte_fault() */ @@ -4156,7 +4138,6 @@ static vm_fault_t do_fault_around(struct vm_fault *vmf) vmf->prealloc_pte = pte_alloc_one(vmf->vma->vm_mm); if (!vmf->prealloc_pte) return VM_FAULT_OOM; - smp_wmb(); /* See comment in __pte_alloc() */ } return vmf->vma->vm_ops->map_pages(vmf, start_pgoff, end_pgoff); @@ -4831,13 +4812,13 @@ int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address) if (!new) return -ENOMEM; - smp_wmb(); /* See comment in __pte_alloc */ - spin_lock(&mm->page_table_lock); - if (pgd_present(*pgd)) /* Another has populated it */ + if (pgd_present(*pgd)) { /* Another has populated it */ p4d_free(mm, new); - else + } else { + smp_wmb(); /* See comment in pmd_install() */ pgd_populate(mm, pgd, new); + } spin_unlock(&mm->page_table_lock); return 0; } @@ -4854,11 +4835,10 @@ int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address) if (!new) return -ENOMEM; - smp_wmb(); /* See comment in __pte_alloc */ - spin_lock(&mm->page_table_lock); if (!p4d_present(*p4d)) { mm_inc_nr_puds(mm); + smp_wmb(); /* See comment in pmd_install() */ p4d_populate(mm, p4d, new); } else /* Another has populated it */ pud_free(mm, new); @@ -4879,14 +4859,14 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address) if (!new) return -ENOMEM; - smp_wmb(); /* See comment in __pte_alloc */ - ptl = pud_lock(mm, pud); if (!pud_present(*pud)) { mm_inc_nr_pmds(mm); + smp_wmb(); /* See comment in pmd_install() */ pud_populate(mm, pud, new); - } else /* Another has populated it */ + } else { /* Another has populated it */ pmd_free(mm, new); + } spin_unlock(ptl); return 0; } @@ -5423,7 +5403,6 @@ long copy_huge_page_from_user(struct page *dst_page, unsigned int pages_per_huge_page, bool allow_pagefault) { - void *src = (void *)usr_src; void *page_kaddr; unsigned long i, rc = 0; unsigned long ret_val = pages_per_huge_page * PAGE_SIZE; @@ -5436,8 +5415,7 @@ long copy_huge_page_from_user(struct page *dst_page, else page_kaddr = kmap_atomic(subpage); rc = copy_from_user(page_kaddr, - (const void __user *)(src + i * PAGE_SIZE), - PAGE_SIZE); + usr_src + i * PAGE_SIZE, PAGE_SIZE); if (allow_pagefault) kunmap(subpage); else |