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Subject: Re: [PATCH v5 2/2] staging: ion: create one device entry per heap
To:     Mark Brown <broonie@kernel.org>
Cc:     Benjamin Gaignard <benjamin.gaignard@linaro.org>,
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        Riley Andrews <riandrews@android.com>,
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From:   Laura Abbott <labbott@redhat.com>
Message-ID: <2a9246e0-eafa-7812-6cf4-2482ff1ed158@redhat.com>
Date:   Mon, 16 Oct 2017 15:09:11 -0700
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On 10/10/2017 02:11 AM, Mark Brown wrote:
> On Mon, Oct 09, 2017 at 05:10:37PM -0700, Laura Abbott wrote:
>> On 10/09/2017 03:08 PM, Mark Brown wrote:
>>> On Mon, Oct 09, 2017 at 02:25:47PM -0700, Laura Abbott wrote:
> 
>>>> Anyway, to move this forward I think we need to see a proof of concept
>>>> of using selinux to protect access to specific heaps.
> 
>>> Aren't Unix permissions enough with separate files or am I
>>> misunderstanding what you're looking to see a proof of concept for?
> 
>> The goal is to be able to restrict heap access to certain services
>> and selinux groups on Android so straight unix permissions aren't
>> sufficient.
> 
> Oh, there's Android users for this?  The users I was aware of were
> non-Android.  Though even so I'd have thought that given that SELinux is
> a superset of Unix file permissions it ought to be sufficient to be able
> to use them.  I'd been thinking people were suggesting SELinux as a
> replacement for file permissions, using the single file and the greater
> capabilities of SELinux.
> 
Unix file permissions are necessary but not sufficient, they
can be used separately. Mostly what I want to see before
merging this is an example that splitting the Ion heaps provides
more protection than just keeping /dev/ion.

Thanks,
Laura

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