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Message-ID: <caeb3213f13e57191e362ca04f2892cfa2ccda65.camel@infradead.org>
Subject: Re: [PATCH] x86/speculation: Use AMD specific retpoline for inline
 asm on AMD
From:   David Woodhouse <dwmw2@infradead.org>
To:     Peter Zijlstra <peterz@infradead.org>,
        Zhenzhong Duan <zhenzhong.duan@oracle.com>
Cc:     linux-kernel@vger.kernel.org, mingo@redhat.com,
        konrad.wilk@oracle.com, x86@kernel.org, tglx@linutronix.de,
        Srinivas REDDY Eeda <srinivas.eeda@oracle.com>, bp@suse.de,
        hpa@zytor.com, dhaval.giani@oracle.com
Date:   Tue, 18 Sep 2018 14:32:52 +0100
In-Reply-To: <20180918130316.GP24142@hirez.programming.kicks-ass.net>
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On Tue, 2018-09-18 at 15:03 +0200, Peter Zijlstra wrote:
> > > In original code, it will go to "call *%[thunk_target]\n" while
> > > we have set SPECTRE_V2_RETPOLINE_MINIMAL or
> > > SPECTRE_V2_RETPOLINE_MINIMAL_AMD. Is this expected?
> >=20
> > Yes, that is exactly right -- it does that with or without your change
> > though.
>=20
> Soryr, I wrote that before I noticed the CONFIG_RETPOLINE vs RETPOLINE
> thing.
>=20
> In any case, since retpoline capable compilers are widely available, I'm
> all for making CONFIG_RETPOLINE hard depend on it. That minimal stuff
> really is quite silly.

Yep, now the the compiler support is widespread that makes a lot of
sense.

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