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From: "H. Peter Anvin" <hpa@zytor.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>,
	Brian Gerst <brgerst@gmail.com>, X86 ML <x86@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 4/5] x86/alternatives: Add an auxilary section
Date: Thu, 21 Jan 2016 11:00:03 -0800	[thread overview]
Message-ID: <56A12AB3.90607@zytor.com> (raw)
In-Reply-To: <1453401286-26966-5-git-send-email-bp@alien8.de>

On 01/21/16 10:34, Borislav Petkov wrote:
> From: Borislav Petkov <bp@suse.de>
> 
> Add .altinstr_aux for additional instructions which will be used before
> and/or during patching. All stuff which needs more sophisticated
> patching should go there. See next patch.
> 
> Signed-off-by: Borislav Petkov <bp@suse.de>
> ---
>  arch/x86/kernel/vmlinux.lds.S | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
> index 74e4bf11f562..1335ff4854ae 100644
> --- a/arch/x86/kernel/vmlinux.lds.S
> +++ b/arch/x86/kernel/vmlinux.lds.S
> @@ -244,6 +244,15 @@ SECTIONS
>  	 */
>  	.altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) {
>  		*(.altinstr_replacement)
> +		/*
> +		 * Section for code used exclusively before alternatives are
> +		 * run. All references to such code must be patched out by
> +		 * alternatives, normally by using a patch with
> +		 * X86_FEATURE_ALWAYS.
> +		 *
> +		 * See static_cpu_has() for an example.
> +		 */
> +		*(.altinstr_aux)
>  	}

NAK on this being part of .altinstr_replacement (if anything it ought to
simply be part of .text.init).  Otherwise fine.

	-hpa

  reply	other threads:[~2016-01-21 19:00 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-01-21 18:34 [RFC PATCH 0/5] x86/cpufeature: Cleanups and improvements Borislav Petkov
2016-01-21 18:34 ` [PATCH 1/5] x86/cpufeature: Carve out X86_FEATURE_* Borislav Petkov
2016-01-21 18:57   ` H. Peter Anvin
2016-01-21 19:03     ` Borislav Petkov
2016-01-22 11:19       ` Borislav Petkov
2016-02-03 14:36         ` David Howells
2016-01-21 18:34 ` [PATCH 2/5] x86/cpufeature: Remove static_cpu_has() Borislav Petkov
2016-01-21 19:04   ` Andy Lutomirski
2016-01-21 19:39     ` Borislav Petkov
2016-01-21 19:41       ` H. Peter Anvin
2016-01-21 19:51         ` Borislav Petkov
2016-01-21 19:05   ` H. Peter Anvin
2016-01-21 18:34 ` [PATCH 3/5] x86/cpufeature: Get rid of the non-asm goto variant Borislav Petkov
2016-01-21 18:59   ` H. Peter Anvin
2016-01-21 18:34 ` [PATCH 4/5] x86/alternatives: Add an auxilary section Borislav Petkov
2016-01-21 19:00   ` H. Peter Anvin [this message]
2016-01-21 19:07     ` Borislav Petkov
2016-01-21 19:10       ` H. Peter Anvin
2016-01-21 18:34 ` [PATCH 5/5] x86/alternatives: Discard dynamic check after init Borislav Petkov
2016-01-21 19:03   ` H. Peter Anvin
2016-01-21 21:53 ` [RFC PATCH 0/5] x86/cpufeature: Cleanups and improvements Brian Gerst
2016-01-21 22:20   ` Borislav Petkov

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