linux-kernel - Re: bug: keep_bootcon and early printk together can lead to (invisible) kernel panic

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Date:	Thu, 21 Feb 2013 17:46:12 +0200
From:	Aaro Koskinen <aaro.koskinen@....fi>
To:	"Patrik, Kluba" <pkluba@...sion.com>
Cc:	linux-mips@...ux-mips.org, linux-kernel@...r.kernel.org
Subject: Re: bug: keep_bootcon and early printk together can lead to
 (invisible) kernel panic

On Thu, Feb 21, 2013 at 03:37:17PM +0100, Patrik, Kluba wrote:
> I had a silent lockup on one of our embedded system under development.
> It was not easy to track it down, so here's what I discovered, in case
> somebody runs into similar trouble.
> Using 'keep_bootcon' command line parameter, and enabling early printk
> can lead to a kernel panic. At least on MIPS, it does. The problem is
> that in arch/mips/kernel/early_printk.c everything is declared as
> __init and __initdata, so they are being freed, when the kernel
> frees .init.* sections. If 'keep_bootcon' is given, the early console
> does not get unregistered, and the entry in the console_drivers list
> can point (will, believe me) to garbage data. It's up to you to imagine
> the effects...

I also ran into this recently, this should fix it:

	http://marc.info/?l=linux-kernel&m=136062078931024&w=2

A.
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