Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754707Ab1FOKHb (ORCPT ); Wed, 15 Jun 2011 06:07:31 -0400 Received: from cantor2.suse.de ([195.135.220.15]:47740 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751500Ab1FOKHa (ORCPT ); Wed, 15 Jun 2011 06:07:30 -0400 Subject: Re: bug: kernel 3.0-rc3 not relocatable on i386? From: Petr Tesarik To: Maarten Lankhorst Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <1308132078.4641.38.camel@nathan.suse.cz> References: <1308125533.4641.33.camel@nathan.suse.cz> <1308132078.4641.38.camel@nathan.suse.cz> Content-Type: text/plain; charset="UTF-8" Organization: SUSE LINUX Date: Wed, 15 Jun 2011 12:07:28 +0200 Message-Id: <1308132448.4641.41.camel@nathan.suse.cz> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1.1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2480 Lines: 64 Petr Tesarik píše v St 15. 06. 2011 v 12:01 +0200: > Maarten Lankhorst píše v St 15. 06. 2011 v 11:21 +0200: > > Hi Petr, > > > > 2011/6/15 Petr Tesarik : > > > Hi all, > > > > > > it seems that the 3.0-rc3 kernel is not relocatable on i386. I get > > > warnings about jiffies being an absolute symbol, and indeed, when GRUB > > > loads the kernel at a non-default address, jiffies is not relocated. > > > > > > In my example the kernel is configured with > > > CONFIG_PHYSICAL_START=0x1000000 > > > CONFIG_PHYSICAL_ALIGN=0x200000 > > > CONFIG_RELOCATABLE=y > > > and loaded at 0x200000 by GRUB. > > > > > > Booting fails when checking whether the timer works, because do_timer() > > > increments jiffies_64, but timer_irq_works() checks jiffies. The code > > > looks like this: > > > > > > c13daab7: 8b 3d 40 7a 39 c1 mov 0xc1397a40,%edi > > > > > > but arch/x86/boot/compressed/vmlinux.relocs does not contain c13daaba. > > > Consequently, timer_irq_works() reads the wrong memory location and > > > fails, causing a panic: > > > > > > kernel panic: IO-APIC + timer doesn't work! Boot with apic=debug and > > > send a report. Then try booting with the 'noapic' option. > > > > > > Needless to say, the kernel freezes a few initcalls later when booted > > > with noapic, because IO-APIC worked fine, in fact. I verified that by > > > inserting a debugging printk() in do_timer(), and I also verified with > > > that printk() that the address of jiffies_64 and the address of jiffies > > > differ at run time. > > > > > > Any idea how to fix this? > > Does reverting this commit fix it? > > Isn't this related to VDSO? I've got no troubles with the VDSO. It's > just that the kernel assumes a fixed location of jiffies (in the kernel > direct mapping), so it cannot be relocated. > > OTOH this must have worked the other day, so searching for the commit > that broke it is a good hint. I'll try it here, too. Ah, it turns out this is in fact reported here: http://sourceware.org/bugzilla/show_bug.cgi?id=12327 But the patch was reverted by commit 6b35eb9ddcddde7b510726de03fae071178f1ec4, so these binutils have been broken again since January. Yes, I've got binutils-2.21 here. :/ Petr -- 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/