Messages in this thread | | | From | Andrew Lutomirski <> | Date | Wed, 15 Jun 2011 07:17:00 -0400 | Subject | Re: bug: kernel 3.0-rc3 not relocatable on i386? |
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On Wed, Jun 15, 2011 at 4:12 AM, Petr Tesarik <ptesarik@suse.cz> wrote: > 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?
This could be a regression in 8c49d9a74bac5ea3f18480307057241b808fcc0c, but I haven't spotted it yet. I'm having trouble reproducing this, though: I see the relocation in the output of relocs --text.
Can you send me your .config? I'll fiddle with it.
--Andy -- 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/
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