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From: Baoquan He <bhe@redhat.com>
To: Borislav Petkov <bp@suse.de>
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com,
	mingo@redhat.com, x86@kernel.org, keescook@chromium.org,
	yinghai@kernel.org, thgarnie@google.com, kuleshovmail@gmail.com,
	luto@kernel.org, mcgrof@kernel.org, anderson@redhat.com,
	dyoung@redhat.com, xlpang@redhat.com
Subject: Re: [PATCH v2 2/2] x86/KASLR/64: Determine kernel text mapping size at runtime
Date: Sat, 10 Dec 2016 20:27:57 +0800	[thread overview]
Message-ID: <20161210122757.GE1034@x1> (raw)
In-Reply-To: <20161210103151.56d7k2iwwwu5acmw@pd.tnic>

On 12/10/16 at 11:31am, Borislav Petkov wrote:
> On Fri, Dec 09, 2016 at 10:41:58PM +0800, Baoquan He wrote:
> > X86 64 kernel takes KERNEL_IMAGE_SIZE as the kernel text mapping size,
> > and it's fixed as compiling time, changing from 512M to 1G as long as
> > CONFIG_RANDOMIZE_BASE is enabled, though people specify kernel option
> > "nokaslr" explicitly.
> > 
> > This could be a wrong behaviour.
> 
> A bunch of changes just because "this could be a wrong behavior". I'm
> not really persuaded.


Well, then apologize for this wrong expression. It should be "This is
a wrong behaviour."

Whether CONFIG_RANDOMIZE_BASE is yes or not, with 'nokaslr' specified,
Kernel text mapping size should be 512M, just the same as no kaslr code
compiled in.

Thanks
Baoquan

  reply	other threads:[~2016-12-10 12:28 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-09 14:41 [PATCH v2 0/2] Determine kernel text mapping size at runtime for x86_64 Baoquan He
2016-12-09 14:41 ` [PATCH v2 1/2] x86/64: Make kernel text mapping always take one whole page table in early boot code Baoquan He
2016-12-09 14:41 ` [PATCH v2 2/2] x86/KASLR/64: Determine kernel text mapping size at runtime Baoquan He
2016-12-10 10:31   ` Borislav Petkov
2016-12-10 12:27     ` Baoquan He [this message]
2016-12-10 12:33       ` Borislav Petkov
2016-12-10 13:41         ` Baoquan He
2016-12-10 16:28           ` Borislav Petkov
2016-12-11 10:58             ` Baoquan He
2016-12-11 12:06               ` Borislav Petkov
2016-12-12  2:32                 ` Baoquan He

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