linux-kernel - Re: [PATCH 02/17] x86, lto: Mark all top level asm statements as .text

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Message-ID: <20190326213803.GN18020@tassilo.jf.intel.com>
Date:   Tue, 26 Mar 2019 14:38:03 -0700
From:   Andi Kleen <ak@...ux.intel.com>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     Andi Kleen <andi@...stfloor.org>, x86@...nel.org,
        akpm@...ux-foundation.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 02/17] x86, lto: Mark all top level asm statements as
 .text

On Tue, Mar 26, 2019 at 06:03:59PM +0100, Thomas Gleixner wrote:
> Andi,
> 
> On Thu, 21 Mar 2019, Andi Kleen wrote:
> 
> > With gcc 8 toplevel assembler statements that do not mark themselves
> > as .text may end up in other sections.
> 
> Which is clearly a change in behaviour. Is that intended or just yet
> another feature of GCC?

I'm not sure it's a new behavior, but I've seen it first
with gcc 8.

> 
> Your subject says: 'x86, lto:'
> 
> So is this a LTO related problem or is the section randomization
> independent of LTO?

The basic behavior is independent of LTO, but I've only seen
failures with LTO. But I believe in theory it could lead
to failures even without LTO.

-Andi