Re: [PATCH] ramoops: Add a device file for ramoops buffer access.

From: Marco Stornelli
Date: Tue Nov 08 2011 - 02:58:10 EST


2011/11/8 Kees Cook <keescook@xxxxxxxxxxxx>:
> Hi Bryan,
>
> On Mon, Nov 07, 2011 at 04:06:00PM -0800, Bryan Freed wrote:
>> Add a /dev/ramoops device file that gives direct access to ramoops buffers.
>> This interface is cleaner than using /dev/mem to access the buffers because
>> we no longer need to lseek() or (for ARM) mmap() to an address specified in
>> the sysfs mem_address file.
>
> This looks pretty good, except that I'd also want to remove all the module
> parameters since this would bypass CONFIG_STRICT_DEVMEM (imagine a
> malicious root user loading this module to spy on RAM via the new
> interface).

First of all my ack for the Bryan's patch.
The behavior about strict /dev/mem should be depends on the
reservation type, I mean if the driver calls request_mem_region
instead of request_mem_region_exclusive. Since ramoops uses the no
exclusive version I think no problems should occurs.

Marco
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