linux-kernel - Re: [RFC v4 07/18] objtool: Introduce INSN

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Message-ID: <20190822200406.jc3yf77pomxxwep6@treble>
Date:   Thu, 22 Aug 2019 15:04:06 -0500
From:   Josh Poimboeuf <jpoimboe@...hat.com>
To:     Raphael Gault <raphael.gault@....com>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        peterz@...radead.org, catalin.marinas@....com, will.deacon@....com,
        julien.thierry.kdev@...il.com, raph.gault+kdev@...il.com
Subject: Re: [RFC v4 07/18] objtool: Introduce INSN_UNKNOWN type

On Fri, Aug 16, 2019 at 01:23:52PM +0100, Raphael Gault wrote:
> On arm64 some object files contain data stored in the .text section.
> This data is interpreted by objtool as instruction but can't be
> identified as a valid one. In order to keep analysing those files we
> introduce INSN_UNKNOWN type. The "unknown instruction" warning will thus
> only be raised if such instructions are uncountered while validating an
> execution branch.
> 
> This change doesn't impact the x86 decoding logic since 0 is still used
> as a way to specify an unknown type, raising the "unknown instruction"
> warning during the decoding phase still.
> 
> Signed-off-by: Raphael Gault <raphael.gault@....com>

Is there a reason such data can't be moved to .rodata?  That would seem
like the proper fix.

-- 
Josh