[PATCH] execute-in-place fixes
[linux-3.10.git] / mm / filemap_xip.c
index 4553b2c5aab4e42a519c5450fea6f70e7faae6bd..8c199f537732088310c0e490cebe92c7414076bb 100644 (file)
@@ -68,13 +68,12 @@ do_xip_mapping_read(struct address_space *mapping,
                if (unlikely(IS_ERR(page))) {
                        if (PTR_ERR(page) == -ENODATA) {
                                /* sparse */
-                               page = virt_to_page(empty_zero_page);
+                               page = ZERO_PAGE(0);
                        } else {
                                desc->error = PTR_ERR(page);
                                goto out;
                        }
-               } else
-                       BUG_ON(!PageUptodate(page));
+               }
 
                /* If users can be writing to this page using arbitrary
                 * virtual addresses, take care about potential aliasing
@@ -84,8 +83,7 @@ do_xip_mapping_read(struct address_space *mapping,
                        flush_dcache_page(page);
 
                /*
-                * Ok, we have the page, and it's up-to-date, so
-                * now we can copy it to user space...
+                * Ok, we have the page, so now we can copy it to user space...
                 *
                 * The actor routine returns how many bytes were actually used..
                 * NOTE! This may not be the same as how much of a user buffer
@@ -164,7 +162,7 @@ EXPORT_SYMBOL_GPL(xip_file_sendfile);
  * xip_write
  *
  * This function walks all vmas of the address_space and unmaps the
- * empty_zero_page when found at pgoff. Should it go in rmap.c?
+ * ZERO_PAGE when found at pgoff. Should it go in rmap.c?
  */
 static void
 __xip_unmap (struct address_space * mapping,
@@ -187,7 +185,7 @@ __xip_unmap (struct address_space * mapping,
                 * We need the page_table_lock to protect us from page faults,
                 * munmap, fork, etc...
                 */
-               pte = page_check_address(virt_to_page(empty_zero_page), mm,
+               pte = page_check_address(ZERO_PAGE(address), mm,
                                         address);
                if (!IS_ERR(pte)) {
                        /* Nuke the page table entry. */
@@ -230,7 +228,6 @@ xip_file_nopage(struct vm_area_struct * area,
 
        page = mapping->a_ops->get_xip_page(mapping, pgoff*(PAGE_SIZE/512), 0);
        if (!IS_ERR(page)) {
-               BUG_ON(!PageUptodate(page));
                return page;
        }
        if (PTR_ERR(page) != -ENODATA)
@@ -245,12 +242,11 @@ xip_file_nopage(struct vm_area_struct * area,
                        pgoff*(PAGE_SIZE/512), 1);
                if (IS_ERR(page))
                        return NULL;
-               BUG_ON(!PageUptodate(page));
                /* unmap page at pgoff from all other vmas */
                __xip_unmap(mapping, pgoff);
        } else {
-               /* not shared and writable, use empty_zero_page */
-               page = virt_to_page(empty_zero_page);
+               /* not shared and writable, use ZERO_PAGE() */
+               page = ZERO_PAGE(address);
        }
 
        return page;
@@ -319,8 +315,6 @@ __xip_file_write(struct file *filp, const char __user *buf,
                        break;
                }
 
-               BUG_ON(!PageUptodate(page));
-
                copied = filemap_copy_from_user(page, offset, buf, bytes);
                flush_dcache_page(page);
                if (likely(copied > 0)) {
@@ -435,8 +429,7 @@ xip_truncate_page(struct address_space *mapping, loff_t from)
                        return 0;
                else
                        return PTR_ERR(page);
-       } else
-               BUG_ON(!PageUptodate(page));
+       }
        kaddr = kmap_atomic(page, KM_USER0);
        memset(kaddr + offset, 0, length);
        kunmap_atomic(kaddr, KM_USER0);