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Date: Sun, 14 Jan 2018 09:53:45 -0600
From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Borislav Petkov <bp@alien8.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>,
        Andi Kleen <ak@linux.intel.com>, Paul Turner <pjt@google.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
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        Tim Chen <tim.c.chen@linux.intel.com>,
        Dave Hansen <dave.hansen@intel.com>, tglx@linutronix.de,
        Kees Cook <keescook@google.com>,
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        Peter Zijlstra <peterz@infradead.org>,
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        Jiri Kosina <jikos@kernel.org>, gnomes@lxorguk.ukuu.org.uk,
        x86@kernel.org, thomas.lendacky@amd.com
Subject: Re: [PATCH v8 03/12] x86/retpoline: Add initial retpoline support
Message-ID: <20180114155345.ozxzh6zbi3or37wz@treble>
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On Sun, Jan 14, 2018 at 04:02:19PM +0100, Borislav Petkov wrote:
> On Thu, Jan 11, 2018 at 09:46:25PM +0000, David Woodhouse wrote:
> > +/*
> > + * This should be used immediately before a retpoline alternative.  It tells
> > + * objtool where the retpolines are so that it can make sense of the control
> > + * flow by just reading the original instruction(s) and ignoring the
> > + * alternatives.
> > + */
> > +.macro ANNOTATE_NOSPEC_ALTERNATIVE
> > +	.Lannotate_\@:
> > +	.pushsection .discard.nospec
> > +	.long .Lannotate_\@ - .
> > +	.popsection
> > +.endm
> 
> Hey Josh, what happened to parsing only the retpoline-related
> .altinstructions sections with the X86_FEATURE bits? Or is this
> annotation used for something more additionally?

Yeah, that idea came after this patch was already written.  I haven't
implemented it yet.

-- 
Josh