diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 74 |
1 files changed, 28 insertions, 46 deletions
diff --git a/mm/memory.c b/mm/memory.c index 6bad4c4064e..da91b7bf998 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -840,23 +840,8 @@ check_user_page_readable(struct mm_struct *mm, unsigned long address) { return __follow_page(mm, address, /*read*/1, /*write*/0) != NULL; } - EXPORT_SYMBOL(check_user_page_readable); -/* - * Given a physical address, is there a useful struct page pointing to - * it? This may become more complex in the future if we start dealing - * with IO-aperture pages for direct-IO. - */ - -static inline struct page *get_page_map(struct page *page) -{ - if (!pfn_valid(page_to_pfn(page))) - return NULL; - return page; -} - - static inline int untouched_anonymous_page(struct mm_struct* mm, struct vm_area_struct *vma, unsigned long address) @@ -887,7 +872,6 @@ untouched_anonymous_page(struct mm_struct* mm, struct vm_area_struct *vma, return 0; } - int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, int len, int write, int force, struct page **pages, struct vm_area_struct **vmas) @@ -951,21 +935,21 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, } spin_lock(&mm->page_table_lock); do { - struct page *map; + struct page *page; int lookup_write = write; cond_resched_lock(&mm->page_table_lock); - while (!(map = follow_page(mm, start, lookup_write))) { + while (!(page = follow_page(mm, start, lookup_write))) { /* * Shortcut for anonymous pages. We don't want * to force the creation of pages tables for - * insanly big anonymously mapped areas that + * insanely big anonymously mapped areas that * nobody touched so far. This is important * for doing a core dump for these mappings. */ if (!lookup_write && untouched_anonymous_page(mm,vma,start)) { - map = ZERO_PAGE(start); + page = ZERO_PAGE(start); break; } spin_unlock(&mm->page_table_lock); @@ -994,30 +978,21 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, spin_lock(&mm->page_table_lock); } if (pages) { - pages[i] = get_page_map(map); - if (!pages[i]) { - spin_unlock(&mm->page_table_lock); - while (i--) - page_cache_release(pages[i]); - i = -EFAULT; - goto out; - } - flush_dcache_page(pages[i]); - if (!PageReserved(pages[i])) - page_cache_get(pages[i]); + pages[i] = page; + flush_dcache_page(page); + if (!PageReserved(page)) + page_cache_get(page); } if (vmas) vmas[i] = vma; i++; start += PAGE_SIZE; len--; - } while(len && start < vma->vm_end); + } while (len && start < vma->vm_end); spin_unlock(&mm->page_table_lock); - } while(len); -out: + } while (len); return i; } - EXPORT_SYMBOL(get_user_pages); static int zeromap_pte_range(struct mm_struct *mm, pmd_t *pmd, @@ -1264,7 +1239,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct * vma, } old_page = pfn_to_page(pfn); - if (!TestSetPageLocked(old_page)) { + if (PageAnon(old_page) && !TestSetPageLocked(old_page)) { int reuse = can_share_swap_page(old_page); unlock_page(old_page); if (reuse) { @@ -1701,19 +1676,16 @@ static int do_swap_page(struct mm_struct * mm, spin_lock(&mm->page_table_lock); page_table = pte_offset_map(pmd, address); if (unlikely(!pte_same(*page_table, orig_pte))) { - pte_unmap(page_table); - spin_unlock(&mm->page_table_lock); - unlock_page(page); - page_cache_release(page); ret = VM_FAULT_MINOR; - goto out; + goto out_nomap; + } + + if (unlikely(!PageUptodate(page))) { + ret = VM_FAULT_SIGBUS; + goto out_nomap; } /* The page isn't present yet, go ahead with the fault. */ - - swap_free(entry); - if (vm_swap_full()) - remove_exclusive_swap_page(page); inc_mm_counter(mm, rss); pte = mk_pte(page, vma->vm_page_prot); @@ -1721,12 +1693,16 @@ static int do_swap_page(struct mm_struct * mm, pte = maybe_mkwrite(pte_mkdirty(pte), vma); write_access = 0; } - unlock_page(page); flush_icache_page(vma, page); set_pte_at(mm, address, page_table, pte); page_add_anon_rmap(page, vma, address); + swap_free(entry); + if (vm_swap_full()) + remove_exclusive_swap_page(page); + unlock_page(page); + if (write_access) { if (do_wp_page(mm, vma, address, page_table, pmd, pte) == VM_FAULT_OOM) @@ -1741,6 +1717,12 @@ static int do_swap_page(struct mm_struct * mm, spin_unlock(&mm->page_table_lock); out: return ret; +out_nomap: + pte_unmap(page_table); + spin_unlock(&mm->page_table_lock); + unlock_page(page); + page_cache_release(page); + goto out; } /* |