diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 151 |
1 files changed, 21 insertions, 130 deletions
diff --git a/mm/memory.c b/mm/memory.c index f82b359b2745..2a8430844b6d 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -966,7 +966,7 @@ no_page_table: * has touched so far, we don't want to allocate page tables. */ if (flags & FOLL_ANON) { - page = ZERO_PAGE(address); + page = ZERO_PAGE(0); if (flags & FOLL_GET) get_page(page); BUG_ON(flags & FOLL_WRITE); @@ -1111,95 +1111,6 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, } EXPORT_SYMBOL(get_user_pages); -static int zeromap_pte_range(struct mm_struct *mm, pmd_t *pmd, - unsigned long addr, unsigned long end, pgprot_t prot) -{ - pte_t *pte; - spinlock_t *ptl; - int err = 0; - - pte = pte_alloc_map_lock(mm, pmd, addr, &ptl); - if (!pte) - return -EAGAIN; - arch_enter_lazy_mmu_mode(); - do { - struct page *page = ZERO_PAGE(addr); - pte_t zero_pte = pte_wrprotect(mk_pte(page, prot)); - - if (unlikely(!pte_none(*pte))) { - err = -EEXIST; - pte++; - break; - } - page_cache_get(page); - page_add_file_rmap(page); - inc_mm_counter(mm, file_rss); - set_pte_at(mm, addr, pte, zero_pte); - } while (pte++, addr += PAGE_SIZE, addr != end); - arch_leave_lazy_mmu_mode(); - pte_unmap_unlock(pte - 1, ptl); - return err; -} - -static inline int zeromap_pmd_range(struct mm_struct *mm, pud_t *pud, - unsigned long addr, unsigned long end, pgprot_t prot) -{ - pmd_t *pmd; - unsigned long next; - int err; - - pmd = pmd_alloc(mm, pud, addr); - if (!pmd) - return -EAGAIN; - do { - next = pmd_addr_end(addr, end); - err = zeromap_pte_range(mm, pmd, addr, next, prot); - if (err) - break; - } while (pmd++, addr = next, addr != end); - return err; -} - -static inline int zeromap_pud_range(struct mm_struct *mm, pgd_t *pgd, - unsigned long addr, unsigned long end, pgprot_t prot) -{ - pud_t *pud; - unsigned long next; - int err; - - pud = pud_alloc(mm, pgd, addr); - if (!pud) - return -EAGAIN; - do { - next = pud_addr_end(addr, end); - err = zeromap_pmd_range(mm, pud, addr, next, prot); - if (err) - break; - } while (pud++, addr = next, addr != end); - return err; -} - -int zeromap_page_range(struct vm_area_struct *vma, - unsigned long addr, unsigned long size, pgprot_t prot) -{ - pgd_t *pgd; - unsigned long next; - unsigned long end = addr + size; - struct mm_struct *mm = vma->vm_mm; - int err; - - BUG_ON(addr >= end); - pgd = pgd_offset(mm, addr); - flush_cache_range(vma, addr, end); - do { - next = pgd_addr_end(addr, end); - err = zeromap_pud_range(mm, pgd, addr, next, prot); - if (err) - break; - } while (pgd++, addr = next, addr != end); - return err; -} - pte_t * fastcall get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl) { pgd_t * pgd = pgd_offset(mm, addr); @@ -1717,16 +1628,11 @@ gotten: if (unlikely(anon_vma_prepare(vma))) goto oom; - if (old_page == ZERO_PAGE(address)) { - 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); - } + VM_BUG_ON(old_page == ZERO_PAGE(0)); + new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address); + if (!new_page) + goto oom; + cow_user_page(new_page, old_page, address, vma); /* * Re-check the pte - we dropped the lock @@ -2252,39 +2158,24 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, spinlock_t *ptl; pte_t entry; - if (write_access) { - /* Allocate our own private page. */ - pte_unmap(page_table); - - if (unlikely(anon_vma_prepare(vma))) - goto oom; - page = alloc_zeroed_user_highpage_movable(vma, address); - if (!page) - goto oom; - - entry = mk_pte(page, vma->vm_page_prot); - entry = maybe_mkwrite(pte_mkdirty(entry), vma); + /* Allocate our own private page. */ + pte_unmap(page_table); - page_table = pte_offset_map_lock(mm, pmd, address, &ptl); - if (!pte_none(*page_table)) - goto release; - inc_mm_counter(mm, anon_rss); - lru_cache_add_active(page); - page_add_new_anon_rmap(page, vma, address); - } else { - /* Map the ZERO_PAGE - vm_page_prot is readonly */ - page = ZERO_PAGE(address); - page_cache_get(page); - entry = mk_pte(page, vma->vm_page_prot); + if (unlikely(anon_vma_prepare(vma))) + goto oom; + page = alloc_zeroed_user_highpage_movable(vma, address); + if (!page) + goto oom; - ptl = pte_lockptr(mm, pmd); - spin_lock(ptl); - if (!pte_none(*page_table)) - goto release; - inc_mm_counter(mm, file_rss); - page_add_file_rmap(page); - } + entry = mk_pte(page, vma->vm_page_prot); + entry = maybe_mkwrite(pte_mkdirty(entry), vma); + page_table = pte_offset_map_lock(mm, pmd, address, &ptl); + if (!pte_none(*page_table)) + goto release; + inc_mm_counter(mm, anon_rss); + lru_cache_add_active(page); + page_add_new_anon_rmap(page, vma, address); set_pte_at(mm, address, page_table, entry); /* No need to invalidate - it was non-present before */ |