Date: Tue, 28 Apr 2015 17:57:14 +0200 (CEST)
From: Jiri Kosina <jkosina@suse.cz>
To: x86@kernel.org, Borislav Petkov <bp@alien8.de>
cc: Josh Poimboeuf <jpoimboe@redhat.com>, Kees Cook <keescook@chromium.org>,
        Seth Jennings <sjenning@redhat.com>, Vojtech Pavlik <vojtech@suse.cz>,
        linux-kernel@vger.kernel.org, live-patching@vger.kernel.org
Subject: Re: [PATCH v2 1/2] x86: introduce kaslr_offset()
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On Tue, 28 Apr 2015, Jiri Kosina wrote:

> Offset that has been chosen for kaslr during kernel decompression can be 
> easily computed as a difference between _text and __START_KERNEL. We are 
> already making use of this in dump_kernel_offset() notifier and in 
> arch_crash_save_vmcoreinfo().
> 
> Introduce kaslr_offset() that makes this computation instead of 
> hard-coding it, so that other kernel code (such as live patching) can make 
> use of it. Also convert existing users to make use of it.
> 
> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
> ---
> 
> It'd be great to potentially have Ack from x86 guys for this patch so that 
> I could take it through livepatching.git with the depending 2/2 patch. 
> Thanks.
> 
> v1 -> v2: convert arch_crash_save_vmcoreinfo(), as spotted by Josh 
> 	  Poimboeuf.

FWIW this patch is equivalent transofrmation without any effects on the 
resulting code:

	$ diff -u vmlinux.old.asm vmlinux.new.asm
	--- vmlinux.old.asm     2015-04-28 17:55:19.520983368 +0200
	+++ vmlinux.new.asm     2015-04-28 17:55:24.141206072 +0200
	@@ -1,5 +1,5 @@
	 
	-vmlinux.old:     file format elf64-x86-64
	+vmlinux.new:     file format elf64-x86-64
	 
	 
	 Disassembly of section .text:
	$

-- 
Jiri Kosina
SUSE Labs
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