patch-2.3.26 linux/mm/memory.c

• Lines: 78
• Date: Thu Nov 4 19:36:33 1999
• Orig file: v2.3.25/linux/mm/memory.c
• Orig date: Mon Nov 1 13:56:27 1999

diff -u --recursive --new-file v2.3.25/linux/mm/memory.c linux/mm/memory.c
@@ -58,9 +58,9 @@
  * a common occurrence (no need to read the page to know
  * that it's zero - better for the cache and memory subsystem).
  */
-static inline void copy_cow_page(struct page * from, struct page * to)
+static inline void copy_cow_page(struct page * from, struct page * to, unsigned long address)
 {
-	if (from == ZERO_PAGE(to)) {
+	if (from == ZERO_PAGE(address)) {
 		clear_highpage(to);
 		return;
 	}
@@ -416,11 +416,11 @@
  * Given a physical address, is there a useful struct page pointing to it?
  */
 
-struct page * get_page_map(struct page *page)
+struct page * get_page_map(struct page *page, unsigned long vaddr)
 {
 	if (MAP_NR(page) >= max_mapnr)
 		return 0;
-	if (page == ZERO_PAGE(page))
+	if (page == ZERO_PAGE(vaddr))
 		return 0;
 	if (PageReserved(page))
 		return 0;
@@ -484,7 +484,7 @@
 			dprintk (KERN_ERR "Missing page in map_user_kiobuf\n");
 			goto retry;
 		}
-		map = get_page_map(map);
+		map = get_page_map(map, ptr);
 		if (map) {
 			if (TryLockPage(map)) {
 				goto retry;
@@ -743,7 +743,7 @@
 		return 0;
 	}
 	flush_page_to_ram(page);
-	set_pte(pte, pte_mkwrite(page_pte_prot(page, PAGE_COPY)));
+	set_pte(pte, pte_mkwrite(mk_pte(page, PAGE_COPY)));
 /* no need for flush_tlb */
 	return page;
 }
@@ -819,7 +819,7 @@
 	if (pte_val(*page_table) == pte_val(pte)) {
 		if (PageReserved(old_page))
 			++vma->vm_mm->rss;
-		copy_cow_page(old_page, new_page);
+		copy_cow_page(old_page, new_page, address);
 		flush_page_to_ram(new_page);
 		flush_cache_page(vma, address);
 		set_pte(page_table, pte_mkwrite(pte_mkdirty(mk_pte(new_page, vma->vm_page_prot))));
@@ -1051,8 +1051,7 @@
  * As this is called only for pages that do not currently exist, we
  * do not need to flush old virtual caches or the TLB.
  *
- * This is called with the MM semaphore and the kernel lock held.
- * We need to release the kernel lock as soon as possible..
+ * This is called with the MM semaphore held.
  */
 static int do_no_page(struct task_struct * tsk, struct vm_area_struct * vma,
 	unsigned long address, int write_access, pte_t *page_table)
@@ -1069,10 +1068,10 @@
 	 * essentially an early COW detection.
 	 */
 	new_page = vma->vm_ops->nopage(vma, address & PAGE_MASK, (vma->vm_flags & VM_SHARED)?0:write_access);
-	if (!new_page)
-		return 0;	/* SIGBUS - but we _really_ should know whether it is OOM or SIGBUS */
-	if (new_page == (struct page *)-1)
-		return -1;	/* OOM */
+	if (new_page == NULL)	/* no page was available -- SIGBUS */
+		return 0;
+	if (new_page == NOPAGE_OOM)
+		return -1;
 	++tsk->maj_flt;
 	++vma->vm_mm->rss;
 	/*