[linuxsh-dev] Bug fix for dis-contiguous page

[NIIBE Y. <gn...@m1...>]

Because there's possibility that it's not valid page, we should not
access the member of the page when we check it is valid or not.  This
is a fix.  If we have many nodes, this is not good implementation, 
but I think that we don't have many (two or so).

	Bug fix for dis-contiguous page handling.
	* include/asm-sh/mmzone.h (is_valid_page): New inline function.
	(VALID_PAGE): Use is_valid_page.

Index: include/asm-sh/mmzone.h
===================================================================
RCS file: /cvsroot/linuxsh/kernel/include/asm-sh/mmzone.h,v
retrieving revision 1.2
diff -u -r1.2 mmzone.h
--- include/asm-sh/mmzone.h	2001/07/15 23:26:56	1.2
+++ include/asm-sh/mmzone.h	2001/08/09 06:15:15
@@ -42,11 +42,18 @@
    NODE_MEM_MAP(node)				 		 	\
      + (((phys) - NODE_DATA(node)->node_start_paddr) >> PAGE_SHIFT); })
 
-/* XXX: It's not safe to deref page->virtual... */
-#define VALID_PAGE(page)						      \
-({ unsigned int node = KVADDR_TO_NID(page_address(page)); 		      \
-   ((node < NR_NODES) && 						      \
-    ((unsigned)((page) - NODE_MEM_MAP(node)) < NODE_DATA(node)->node_size) ); \
-})
+static inline int is_valid_page(struct page *page)
+{
+	unsigned int i;
+
+	for (i = 0; i < NR_NODES; i++) {
+		if (page >= NODE_MEM_MAP(i) &&
+		    page < NODE_MEM_MAP(i) + NODE_DATA(i)->node_size)
+			return 1;
+	}
+	return 0;
+}
+
+#define VALID_PAGE(page)	is_valid_page(page)
 #endif /* CONFIG_DISCONTIGMEM */
 #endif
--