linux-kernel - Re: [PATCH v2 3/3] kexec: extend kexec_file

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Message-Id: <1988385.QMVjiCbb5e@hactar>
Date:	Fri, 05 Aug 2016 17:46:43 -0300
From:	Thiago Jung Bauermann <bauerman@...ux.vnet.ibm.com>
To:	kexec@...ts.infradead.org
Cc:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Vivek Goyal <vgoyal@...hat.com>,
	Dave Young <dyoung@...hat.com>, Baoquan He <bhe@...hat.com>,
	Arnd Bergmann <arnd@...db.de>,
	Michael Ellerman <michael@...erman.id.au>,
	Russell King - ARM Linux <linux@...linux.org.uk>,
	Mark Rutland <mark.rutland@....com>,
	Stewart Smith <stewart@...ux.vnet.ibm.com>,
	Jeremy Kerr <jeremy.kerr@....ibm.com>,
	Samuel Mendoza-Jonas <sam@...dozajonas.com>,
	Mimi Zohar <zohar@...ux.vnet.ibm.com>,
	linux-kernel@...r.kernel.org,
	AKASHI Takahiro <takahiro.akashi@...aro.org>,
	linuxppc-dev@...ts.ozlabs.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v2 3/3] kexec: extend kexec_file_load system call

Hi,

Am Dienstag, 26 Juli 2016, 21:24:29 schrieb Thiago Jung Bauermann:
> Notes:
>     This is a new version of the last patch in this series which adds
>     a function where each architecture can verify if the DTB is safe
>     to load:
> 
>     int __weak arch_kexec_verify_buffer(enum kexec_file_type type,
>                                         const void *buf,
>                                         unsigned long size)
>     {
>             return -EINVAL;
>     }
> 
>     I will then provide an implementation in my powerpc patch series
>     which checks that the DTB only contains nodes and properties from a
>     whitelist. arch_kexec_kernel_image_load will copy these properties
>     to the device tree blob the kernel was booted with (and perform
>     other changes such as setting /chosen/bootargs, of course).

Is this approach ok? If so, I'll post a patch next week adding an 
arch_kexec_verify_buffer hook for powerpc to enforce the whitelist, and also 
a new version of the patches implementing kexec_file_load for powerpc on top 
of this series.

Eric, does this address your concerns?

-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center