MIME-Version: 1.0
In-Reply-To: <20160404193803.GK351@pd.tnic>
References: <cover.1459605520.git.luto@kernel.org> <4085070316fc3ab29538d3fcfe282648d1d4ee2e.1459605520.git.luto@kernel.org>
 <20160402183919.GA2538@pd.tnic> <CALCETrUJVDpzNQMsY=_jWNOMer+TdW2p4wES4OBCfYU7gq3fbg@mail.gmail.com>
 <20160402204752.GC2538@pd.tnic> <CALCETrXHR3T3PJwOWRFHTMK5WjhDyTJfaJtkiHd+g7evnqp54A@mail.gmail.com>
 <20160404115206.GG8372@quack.suse.cz> <CALCETrVriftUPNZ8pCQ1x9TWDHnRx8fWUvJgCQToPEOxqMLb3w@mail.gmail.com>
 <20160404160042.GB3448@twins.programming.kicks-ass.net> <20160404193803.GK351@pd.tnic>
From: Andy Lutomirski <luto@amacapital.net>
Date: Mon, 4 Apr 2016 14:31:46 -0700
Message-ID: <CALCETrVvFTrK1pVmjnfWwwq+5P6+1ghMjh4Wwqm05d=00ejYSw@mail.gmail.com>
Subject: Re: [PATCH v5 3/9] x86/head: Move early exception panic code into early_fixup_exception
To: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>, Jan Kara <jack@suse.cz>,
        Paolo Bonzini <pbonzini@redhat.com>,
        xen-devel <Xen-devel@lists.xen.org>,
        Arjan van de Ven <arjan@linux.intel.com>, X86 ML <x86@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Petr Mladek <pmladek@suse.cz>, KVM list <kvm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1082
Lines: 30

On Mon, Apr 4, 2016 at 12:38 PM, Borislav Petkov <bp@alien8.de> 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