Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755389AbYLaFJa (ORCPT ); Wed, 31 Dec 2008 00:09:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750828AbYLaFJV (ORCPT ); Wed, 31 Dec 2008 00:09:21 -0500 Received: from wine.ocn.ne.jp ([122.1.235.145]:62676 "EHLO smtp.wine.ocn.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1749667AbYLaFJV (ORCPT ); Wed, 31 Dec 2008 00:09:21 -0500 To: frederik.deweerdt@xprog.eu Cc: mingo@elte.hu, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com Subject: Re: [2.6.28] NULL pointer dereference at get_stats() From: Tetsuo Handa References: <200812302153.ECH86976.MFLOQFJHtSOOFV@I-love.SAKURA.ne.jp> <20081230155215.GA31531@gambetta> <200812310201.GJH43235.OFFLHFMStOJVOQ@I-love.SAKURA.ne.jp> <20081230213727.GA2001@gambetta> In-Reply-To: <20081230213727.GA2001@gambetta> Message-Id: <200812311409.EEC09369.VtOSLFJFMOOFQH@I-love.SAKURA.ne.jp> X-Mailer: Winbiff [Version 2.50 PL2] X-Accept-Language: ja,en Date: Wed, 31 Dec 2008 14:09:19 +0900 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2905 Lines: 46 Hello. Frederik Deweerdt wrote: > Thanks for the thourough testing. I've reviewed the code, and the only > think that looks weird to me is the case where smp_sanity_check() fails. > The attached patch is an attempt to correct this, Tetsuo, could you > test it? That patch didn't solve. Below are the results (with that patch applied) with more test cases. Case | Result | # of virtual CPUs | # of CPUs recognized | Kernel command line -----+--------+-------------------+----------------------+----------------------------------------- (1) | OK | 2 | 2 | ro root=LABEL=/ (2) | BUG | 2 | 1 | ro root=LABEL=/ noapic nolapic (3) | BUG | 2 | 1 | ro root=LABEL=/ noapic nolapic maxcpus=0 (4) | BUG | 2 | 1 | ro root=LABEL=/ noapic nolapic nosmp (5) | BUG | 2 | 1 | ro root=LABEL=/ maxcpus=0 (6) | BUG | 2 | 1 | ro root=LABEL=/ nosmp (7) | OK | 1 | 1 | ro root=LABEL=/ (8) | OK | 1 | 1 | ro root=LABEL=/ nolapic noapic (9) | OK | 1 | 1 | ro root=LABEL=/ nolapic noapic maxcpus=0 (10) | OK | 1 | 1 | ro root=LABEL=/ nolapic noapic nosmp (11) | OK | 2 | 1 | ro root=LABEL=/ maxcpus=1 (12) | OK | 2 | 2 | ro root=LABEL=/ maxcpus=2 (13) | OK | 2 | 2 | ro root=LABEL=/ maxcpus=4 (14) | BUG | 2 | 1 | ro root=LABEL=/ noapic nolapic maxcpus=1 (15) | OK | 2 | 2 | ro root=LABEL=/ noapic (16) | BUG | 2 | 1 | ro root=LABEL=/ noapic maxcpus=0 (17) | OK | 2 | 1 | ro root=LABEL=/ noapic maxcpus=1 (18) | OK | 2 | 2 | ro root=LABEL=/ noapic maxcpus=2 (19) | BUG | 2 | 1 | ro root=LABEL=/ nolapic (20) | BUG | 2 | 1 | ro root=LABEL=/ nolapic maxcpus=0 (21) | BUG | 2 | 1 | ro root=LABEL=/ nolapic maxcpus=1 (22) | BUG | 2 | 1 | ro root=LABEL=/ nolapic maxcpus=2 "# of CPUs recognized" means "grep -c ^processor /proc/cpcinfo". Well, (2) (19) (22) are obviously wrong. "nolapic" option implies "nosmp" option? Regards. -- 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/