Return-Path: <linux-kernel-owner+willy=40w.ods.org@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id <S318192AbSGWRIt>; Tue, 23 Jul 2002 13:08:49 -0400
Received: (majordomo@vger.kernel.org) by vger.kernel.org
	id <S318188AbSGWRFs>; Tue, 23 Jul 2002 13:05:48 -0400
Received: from garrincha.netbank.com.br ([200.203.199.88]:20231 "HELO
	garrincha.netbank.com.br") by vger.kernel.org with SMTP
	id <S318180AbSGWRFL>; Tue, 23 Jul 2002 13:05:11 -0400
Date: Tue, 23 Jul 2002 14:07:41 -0300 (BRT)
From: Rik van Riel <riel@conectiva.com.br>
X-X-Sender: riel@imladris.surriel.com
To: Linus Torvalds <torvalds@transmeta.com>
cc: Andrew Morton <akpm@zip.com.au>, <linux-kernel@vger.kernel.org>,
       <rmk@arm.linux.org.uk>, <linux-mm@kvack.org>,
       Craig Kulesa <ckulesa@as.arizona.edu>
Subject: [PATCH] urgent rmap bugfix
Message-ID: <Pine.LNX.4.44L.0207231401450.3086-100000@imladris.surriel.com>
X-spambait: aardvark@kernelnewbies.org
X-spammeplease: aardvark@nl.linux.org
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1125
Lines: 38

Hi,

it turns out there was a subtle bug in Craig Kulesa's port of
the rmap patch to 2.5, which is only apparent on non-x86 machines
where pfn 0 isn't valid.

The problem was that zap_pte_range() would clear the pte before
page_remove_rmap() would get called. This means that on these
machines the pte chain would never be removed and the machine
would oops at page_alloc.c line 98...

Thanks to Russell King for helping track down this bug.

please apply,

Rik
-- 
Bravely reimplemented by the knights who say "NIH".

===== mm/rmap.c 1.3 vs edited =====
--- 1.3/mm/rmap.c	Tue Jul 16 18:46:30 2002
+++ edited/mm/rmap.c	Tue Jul 23 14:01:23 2002
@@ -163,7 +163,7 @@
 void page_remove_rmap(struct page * page, pte_t * ptep)
 {
 	struct pte_chain * pc, * prev_pc = NULL;
-	unsigned long pfn = pte_pfn(*ptep);
+	unsigned long pfn = page_to_pfn(page);

 	if (!page || !ptep)
 		BUG();


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/