From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756250AbYKURHu (ORCPT ); Fri, 21 Nov 2008 12:07:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753281AbYKURHi (ORCPT ); Fri, 21 Nov 2008 12:07:38 -0500 Received: from ey-out-2122.google.com ([74.125.78.24]:41979 "EHLO ey-out-2122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755554AbYKURHh (ORCPT ); Fri, 21 Nov 2008 12:07:37 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=BnifH0J6WHN1r0dRF/mVyUKtzym6rfmmCcgLyxRa9U+ZuQUc9a74WdX+M0zAEsxmq4 k1PUGR7dhSp0KlZtk/gy5+QR61PZCQXI0dCJ5WMjKUCFR8xeEE6iCj9YaEIreUeumUUI txlH0VT4Z58+NX1s4zj1N14bFC2s9DMRF2l5g= Date: Fri, 21 Nov 2008 17:07:11 +0000 From: =?utf-8?Q?Am=C3=A9rico?= Wang To: Al Viro Cc: LKML , Andrew Morton , Jeff Dike , user-mode-linux-devel@lists.sourceforge.net Subject: Re: [Patch] uml: fix undeclared variables Message-ID: <20081121170711.GA23653@hack.voiplan.pt> References: <20081118174250.GE3185@hack.voiplan.pt> <20081118192626.GU28946@ZenIV.linux.org.uk> <20081119184014.GD22898@hack.voiplan.pt> <20081119190636.GW28946@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081119190636.GW28946@ZenIV.linux.org.uk> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 19, 2008 at 07:06:36PM +0000, Al Viro wrote: >On Wed, Nov 19, 2008 at 06:40:14PM +0000, Am??rico Wang wrote: >> On Tue, Nov 18, 2008 at 07:26:26PM +0000, Al Viro wrote: >> >On Tue, Nov 18, 2008 at 05:42:51PM +0000, Am??rico Wang wrote: >> >> >> >> Fix three compile errors about undeclared variables in >> >> arch/um/kernel/mem.c. >> > >> >And what, pray tell, would initialize it? >> >> Sorry, I can't fully understand you. I got the following error: >> >> arch/um/kernel/mem.c: In function ???init_highmem???: >> arch/um/kernel/mem.c:177: error: ???pkmap_page_table??? undeclared (first >> use in this function) >> arch/um/kernel/mem.c:177: error: (Each undeclared identifier is >> reported only once >> arch/um/kernel/mem.c:177: error: for each function it appears in.) > >The error is there, all right. However, proposed patch only hides the >real problem. Building uml/i386 with CONFIG_HIGHMEM will result in >a badly broken kernel with that patch, with no visible hints at the >cause of problems. > >You've got it to link, but that's not enough. The problems you are seeing >come from arch/x86/mm/highmem_32.c. It uses several variables from >arch/x86/mm/init_32.c and you have copied them to arch/um. However, getting >these variable defined is not going to make it work - the code that used >to set it had been in init_32.c too and you've just left your copy initialized >to NULL. Which will *not* work. > Thanks for teaching this! I will look deep into this problem. -- "Sometimes the only way to stay sane is to go a little crazy."