Re: [PATCH v5 3/9] x86/head: Move early exception panic code into early_fixup_exception

From: Andy Lutomirski
Date: Mon Apr 04 2016 - 17:32:12 EST


On Mon, Apr 4, 2016 at 12:38 PM, Borislav Petkov <bp@xxxxxxxxx> wrote:
> On Mon, Apr 04, 2016 at 06:00:42PM +0200, Peter Zijlstra wrote:
>> On Mon, Apr 04, 2016 at 08:32:21AM -0700, Andy Lutomirski wrote:
>>
>> > Adding locking would be easy enough, wouldn't it?
>>
>> See patch in this thread..
>>
>> > But do any platforms really boot a second CPU before switching to real
>> > printk?
>>
>> I _only_ use early_printk() as printk() is a quagmire of fail :-)
>
> And since I'm the king of minimalistic changes... this below
> works. However, the problem is that we need to pull up all that
> early_param parsing in order to enable the early console, i.e.
> "earlyprintk=ttyS0,115200" cmdline parsing.
>
> And we can do all that after having setup the IDT. So I'd need to do
> some early dancing with cmdline_find_option_bool(boot_command_line, ...
> in asm or so. Need to think about it more.
>

I'd be nervous about moving early param parsing, especially as part of
the same patch.

Could you do it by moving just the earlyprintk stuff a la
fpu__init_parse_early_param()?

--Andy