Re: Reiser4 und LZO compression

From: Jörn Engel
Date: Mon Aug 28 2006 - 08:41:05 EST


On Sun, 27 August 2006 01:04:28 -0700, Andrew Morton wrote:
>
> Like lib/inflate.c (and this new code should arguably be in lib/).
>
> The problem is that if we clean this up, we've diverged very much from the
> upstream implementation. So taking in fixes and features from upstream
> becomes harder and more error-prone.

I've had an identical argument with Linus about lib/zlib_*. He
decided that he didn't care about diverging, I went ahead and changed
the code. In the process, I merged a couple of outstanding bugfixes
and reduced memory consumption by 25%. Looks like Linus was right on
that one.

> I'd suspect that the maturity of these utilities is such that we could
> afford to turn them into kernel code in the expectation that any future
> changes will be small. But it's not a completely simple call.
>
> (iirc the inflate code had a buffer overrun a while back, which was found
> and fixed in the upstream version).

Dito in lib/zlib_*. lib/inflage.c is only used for the various
in-kernel bootloaders to uncompress a kernel image. Anyone tampering
with the image to cause a buffer overrun already owns the machine
anyway.

Whether any of our experiences with zlib apply to lzo remains a
question, though.

Jörn

--
I've never met a human being who would want to read 17,000 pages of
documentation, and if there was, I'd kill him to get him out of the
gene pool.
-- Joseph Costello
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