Re: 2.6.39.1 immediately reboots/resets on EFI system

From: Matthew Garrett
Date: Sat Jun 11 2011 - 11:29:51 EST


On Fri, Jun 10, 2011 at 04:26:20PM -0700, Yinghai Lu wrote:
> On 06/10/2011 04:03 PM, Matthew Garrett wrote:
> > The medium-term fix is to ensure that the bootloaders don't put the
> > kernel on top of boot services code.
>
> that is not enough, will need to make arch/x86/boot/compressed/head_64.S parse e820 table to find right decompress position.

That's fine, we can ensure we load it where there's enough space.

> > But the short-term fix here is to allocate all boot
> > services regions that don't overlap with the kernel. That'll fix some
> > number of machines and shouldn't break any existing ones.
>
> that is questionable and dangerous. before SetVirtualAddressMap, some function in boot service could be called,
> those data or code for boot services could be overlapped kernel. so kernel code could be damaged by those calling.

Right now it's guaranteed that the system will crash in this situation.
It seems reasonable to give it a fighting chance.

> also that will make our kernel code more messy.

It's code that deals with firmware, so really that's a given...

--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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