Re: [PATCH]: fix the bug of __free_pages() of mm/page_alloc.c

[zhan rongkai]

--- linux-2.6.10.orig/mm/page_alloc.c	2004-12-25 05:33:51.000000000 +0800
+++ linux-2.6.10/mm/page_alloc.c	2005-01-21 11:46:58.000000000 +0800
@@ -788,7 +788,22 @@
 
 fastcall void __free_pages(struct page *page, unsigned int order)
 {
-	if (!PageReserved(page) && put_page_testzero(page)) {
+	if (!PageReserved(page)) {
+#ifdef CONFIG_MMU
+		if (!put_page_testzero(page))
+			return;
+#else
+		int i, result = 1;
+
+		/*
+		 * We need to de-reference all the pages for this order -- see
set_page_refs()
+		 */
+		for (i = 0; i < (1 << order); i++)
+			result &= put_page_testzero(page+i);
+		if (!result)
+			BUG();
+#endif /* CONFIG_MMU */
+
 		if (order == 0)
 			free_hot_page(page);
 		else


On Fri, 21 Jan 2005 11:40:52 +0800, zhan rongkai <zhanrk@xxxxxxxxx> wrote:
> --- linux-2.6.10.orig/mm/page_alloc.c   2004-12-25 05:33:51.000000000 +0800
> +++ linux-2.6.10/mm/page_alloc.c        2005-01-21 11:43:44.000000000 +0800
> @@ -788,7 +788,22 @@
> 
>  fastcall void __free_pages(struct page *page, unsigned int order)
>  {
> -       if (!PageReserved(page) && put_page_testzero(page)) {
> +       if (!PageReserved(page)) {
> +#ifdef CONFIG_MMU
> +               if (!put_page_testzero(page))
> +                       return;
> +#else
> +               int i, result = 1;
> +
> +               /*
> +                * We need to de-reference all the pages for this order -- see
> set_page_refs()
> +                */
> +                for (i = 0; i < (1 << order); i++)
> +                        result &= put_page_testzero(page+i);
> +                if (!result)
> +                        BUG();
> +#endif /* CONFIG_MMU */
> +
>                 if (order == 0)
>                         free_hot_page(page);
>                 else
> 
> --
> Rongkai Zhan
> 


-- 
Rongkai Zhan
-
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