Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754626Ab1FOJgs (ORCPT ); Wed, 15 Jun 2011 05:36:48 -0400 Received: from mail-ey0-f174.google.com ([209.85.215.174]:41549 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754209Ab1FOJgr (ORCPT ); Wed, 15 Jun 2011 05:36:47 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=kSgFhviYI2SKzQVPHGzssi/NuWJi6u6Fb3Db4+ettrUZI625yKmRdh0o/oeODjv9t/ ZyCLnRAr61egKuE8TXrfxLUqBmCeDY7aL+CHtmyJQruYj1sbtUcY4WYDTFuOagAZhDKQ x7fPpNKhGZmueAscUiiEhnichXva/rMSdy5IY= Message-ID: <4DF87D2B.7090201@gmail.com> Date: Wed, 15 Jun 2011 11:36:43 +0200 From: Maarten Lankhorst User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.15) Gecko/20110419 Thunderbird/3.1.9 MIME-Version: 1.0 To: Petr Tesarik CC: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: bug: kernel 3.0-rc3 not relocatable on i386? References: <1308125533.4641.33.camel@nathan.suse.cz> In-Reply-To: <1308125533.4641.33.camel@nathan.suse.cz> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2115 Lines: 59 Hi Petr, Op 15-06-11 10:12, Petr Tesarik schreef: > 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. Can you try this patch? diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index 89aed99..49e666e 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -34,12 +34,11 @@ OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT, CONFIG_OUTPUT_FORMAT) #ifdef CONFIG_X86_32 OUTPUT_ARCH(i386) ENTRY(phys_startup_32) -jiffies = jiffies_64; #else OUTPUT_ARCH(i386:x86-64) ENTRY(phys_startup_64) -jiffies_64 = jiffies; #endif +jiffies_64 = jiffies; #if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA) /* -- 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/