diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/fremap.c | 24 | ||||
| -rw-r--r-- | mm/memory.c | 48 |
2 files changed, 31 insertions, 41 deletions
diff --git a/mm/fremap.c b/mm/fremap.c index f851775..9f381e5 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -55,20 +55,10 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma, pgoff_t size; int err = -ENOMEM; pte_t *pte; - pmd_t *pmd; - pud_t *pud; - pgd_t *pgd; pte_t pte_val; spinlock_t *ptl; - pgd = pgd_offset(mm, addr); - pud = pud_alloc(mm, pgd, addr); - if (!pud) - goto out; - pmd = pmd_alloc(mm, pud, addr); - if (!pmd) - goto out; - pte = pte_alloc_map_lock(mm, pmd, addr, &ptl); + pte = get_locked_pte(mm, addr, &ptl); if (!pte) goto out; @@ -110,20 +100,10 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma, { int err = -ENOMEM; pte_t *pte; - pmd_t *pmd; - pud_t *pud; - pgd_t *pgd; pte_t pte_val; spinlock_t *ptl; - pgd = pgd_offset(mm, addr); - pud = pud_alloc(mm, pgd, addr); - if (!pud) - goto out; - pmd = pmd_alloc(mm, pud, addr); - if (!pmd) - goto out; - pte = pte_alloc_map_lock(mm, pmd, addr, &ptl); + pte = get_locked_pte(mm, addr, &ptl); if (!pte) goto out; diff --git a/mm/memory.c b/mm/memory.c index 990e7dc6..5bfa52a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1146,6 +1146,18 @@ int zeromap_page_range(struct vm_area_struct *vma, return err; } +pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl) +{ + pgd_t * pgd = pgd_offset(mm, addr); + pud_t * pud = pud_alloc(mm, pgd, addr); + if (pud) { + pmd_t * pmd = pmd_alloc(mm, pgd, addr); + if (pmd) + return pte_alloc_map_lock(mm, pmd, addr, ptl); + } + return NULL; +} + /* * This is the old fallback for page remapping. * @@ -1156,10 +1168,7 @@ int zeromap_page_range(struct vm_area_struct *vma, static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *page, pgprot_t prot) { int retval; - pgd_t * pgd; - pud_t * pud; - pmd_t * pmd; - pte_t * pte; + pte_t *pte; spinlock_t *ptl; retval = -EINVAL; @@ -1167,14 +1176,7 @@ static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *pa goto out; retval = -ENOMEM; flush_dcache_page(page); - pgd = pgd_offset(mm, addr); - pud = pud_alloc(mm, pgd, addr); - if (!pud) - goto out; - pmd = pmd_alloc(mm, pud, addr); - if (!pmd) - goto out; - pte = pte_alloc_map_lock(mm, pmd, addr, &ptl); + pte = get_locked_pte(mm, addr, &ptl); if (!pte) goto out; retval = -EBUSY; @@ -1392,8 +1394,15 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo */ if (unlikely(!src)) { void *kaddr = kmap_atomic(dst, KM_USER0); - unsigned long left = __copy_from_user_inatomic(kaddr, (void __user *)va, PAGE_SIZE); - if (left) + void __user *uaddr = (void __user *)(va & PAGE_MASK); + + /* + * This really shouldn't fail, because the page is there + * in the page tables. But it might just be unreadable, + * in which case we just give up and fill the result with + * zeroes. + */ + if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE)) memset(kaddr, 0, PAGE_SIZE); kunmap_atomic(kaddr, KM_USER0); return; @@ -1424,12 +1433,11 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *page_table, pmd_t *pmd, spinlock_t *ptl, pte_t orig_pte) { - struct page *old_page, *src_page, *new_page; + struct page *old_page, *new_page; pte_t entry; int ret = VM_FAULT_MINOR; old_page = vm_normal_page(vma, address, orig_pte); - src_page = old_page; if (!old_page) goto gotten; @@ -1457,7 +1465,7 @@ gotten: if (unlikely(anon_vma_prepare(vma))) goto oom; - if (src_page == ZERO_PAGE(address)) { + if (old_page == ZERO_PAGE(address)) { new_page = alloc_zeroed_user_highpage(vma, address); if (!new_page) goto oom; @@ -1465,7 +1473,7 @@ gotten: new_page = alloc_page_vma(GFP_HIGHUSER, vma, address); if (!new_page) goto oom; - cow_user_page(new_page, src_page, address); + cow_user_page(new_page, old_page, address); } /* @@ -2001,6 +2009,8 @@ static int do_no_page(struct mm_struct *mm, struct vm_area_struct *vma, int anon = 0; pte_unmap(page_table); + BUG_ON(vma->vm_flags & VM_PFNMAP); + if (vma->vm_file) { mapping = vma->vm_file->f_mapping; sequence = mapping->truncate_count; @@ -2033,7 +2043,7 @@ retry: page = alloc_page_vma(GFP_HIGHUSER, vma, address); if (!page) goto oom; - cow_user_page(page, new_page, address); + copy_user_highpage(page, new_page, address); page_cache_release(new_page); new_page = page; anon = 1; |
