Re: [PATCH] arm: mm: Poison freed init memory

From: Russell King - ARM Linux
Date: Tue Jan 11 2011 - 04:06:43 EST


On Mon, Jan 10, 2011 at 09:00:17PM -0800, Stephen Boyd wrote:
> Ok it seems that 0xcc was chosen by Pavel since it's a breakpoint
> instruction (sorry for not noticing that earlier [1]).

It may be on x86, but on ARM:

0: cccccccc stclgt 12, cr12, [ip], {204}

That's a co-processor #12 instruction which will only be executed of
the processor condition codes satisfy 'gt'.

> There was some discussion about handling initdata with Pavel's patch
> but it seems that nothing came of it?

I'm not sure who this Pavel is who you keep referring to - the message
you link to is a discussion between William Irvin and hpa.

> How about we use 0xe7fddef0? This seems to satisfy at least your first
> point for both ARM and Thumb mode (Thumb will branch to the 0xdef0
> instruction).

Yup.
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