Re: 3.12 to 3.13 boot regression bisected - still applies to 3.16

From: Bruno PrÃmont
Date: Tue Aug 05 2014 - 07:51:38 EST


On Tue, 5 Aug 2014 10:18:48 +0100 Matt Fleming wrote:
> On Tue, 05 Aug, at 11:13:30AM, Bruno PrÃmont wrote:
> >
> > I get at least to just before
> > status = efi_call_early(exit_boot_services, handle, key);
> > in eboot.c on line 1310. A efi_printk inserted there is displayed.
>
> This is worth pointing out in case you're unaware, but do you know that
> it's not valid to call efi_printk() after ExitBootServices()? Doing so
> will almost certainly cause your machine to fault.

I am aware that efi_printk() uses boot services!


Now I tried out loops at many places and have gotten up to line 340 in

arch/x86/kernel/head_64.S

System reboots within the following assembler instructions (does not
reach line 359).

So efi_main() returns successfully but the assembler code following it
gets something wrong.

I'm going to try further to determine which line between 340 and 359 is
the "bad" one.

Bruno
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