Re: [PATCH] Allow /dev/{,k}mem to be disabled to prevent kernel from being modified easily

[bert hubert <ahu@ds9a.nl>]

On Sun, Aug 03, 2003 at 09:11:02PM +0200, Willy Tarreau wrote:

> Why not make this change dynamic instead ? eg : your system boots unlocked,
> and definitely locks /dev/{,k}mem once you do something such as
> 
>   echo foo > /proc/path_to_magic_entry
 
I thought about something like that but then for loading modules too - which
would allow for a modular boot but a lock afterwards.

> So the same config can be used with kernel with and without X, it's just a
> matter of runtime configuration. It could even be a sysctl, as long as there's
> no way to unset it.

Well, I fear the runtime overhead - as it is, I suspect this patch is
somewhat inflamatory anyhow ('tough luck you were hacked', 'you are fscked
anyhow').

However, the check would be in {,k}mem_open and in sys_init_module, which
are not heavily used functions.

I'll whip up a dynamic patch soonish - I'm unsure about the right location,
/proc/sys/ something?

Thanks.
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