Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Wed, 5 Feb 2020 18:28:26 +0900
From:   Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To:     John Ogness <john.ogness@linutronix.de>
Cc:     Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
        lijiang <lijiang@redhat.com>, Petr Mladek <pmladek@suse.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Andrea Parri <parri.andrea@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        kexec@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] printk: replace ringbuffer
Message-ID: <20200205092826.GL41358@google.com>
References: <20200128161948.8524-1-john.ogness@linutronix.de>
 <dc4ca9b5-d2a2-03af-c186-204a3aad2399@redhat.com>
 <20200205044848.GH41358@google.com>
 <20200205050204.GI41358@google.com>
 <88827ae2-7af5-347b-29fb-cffb94350f8f@redhat.com>
 <20200205063640.GJ41358@google.com>
 <877e11h0ir.fsf@linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <877e11h0ir.fsf@linutronix.de>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On (20/02/05 10:00), John Ogness wrote:
> On 2020-02-05, Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> wrote:
> >>>> So there is a General protection fault. That's the type of a
> >>>> problem that kills the boot for me as well (different backtrace,
> >>>> tho).
> >>> 
> >>> Do you have CONFIG_RELOCATABLE and CONFIG_RANDOMIZE_BASE (KASLR)
> >>> enabled?
> >> 
> >> Yes. These two options are enabled.
> >> 
> >> CONFIG_RELOCATABLE=y
> >> CONFIG_RANDOMIZE_BASE=y
> >
> > So KASLR kills the boot for me. So does KASAN.
> 
> Sergey, thanks for looking into this already!

Hey, no prob! I can't see how and why that would be KASLR related,
and most likely it's not. Probably we just hit some fault sooner
with it enabled.

So far it seems that reads from /dev/kmsg are causing problems
on my laptop, but it's a bit hard to debug.

Nothing printk-related in my boot params.

	-ss