GEOM_ULZMA

[Pawel Jakub Dawidek]

On Tue, Mar 02, 2010 at 08:32:20PM +0100, Dimitry Andric wrote:
> On 2010-03-02 09:47, Alexandr Rybalko wrote:
> >>>Definiatelly separately, not sure where. There is ongoing discussion
> >>>somwhere on importing this algorithm to the base for tar(1) to use, it
> >>>would be best to have only one copy of code in the tree.
> >I have already said, that it would be good for embedded platforms have 
> >only one copy of the code for the kernel and userland.
> >It is not thought of how done it.
> 
> I think Pawel means the *source* code in this case, not the executable
> code.  E.g. lzma source should most likely go under /usr/src/contrib,
> and be built separately for kernel and userland.

If it is going to be used be the kernel it has to be under sys/.

And yes, I was talking about one copy of the source, not executable.
I think it would be bad idea to do compression in the kernel for
userland applications for many reasons - the most important one is
security. Look at projects like Capsicum where Robert closed for example
gzip in a tight sandbox and gzip is not even set-uid and giving it
chance to gain kernel access when bug is found is very, very bad.
Another reason is performance. You can see how much faster, eg. openssl
crypto is when doing it in userland and when forcing it to use software
crypto from the opencrypto kernel framework.

-- 
Pawel Jakub Dawidek                       http://www.wheelsystems.com
pjd at FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!
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