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SubjectRe: [PATCH 00/23] Crypto keys and module signing
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Rusty Russell <rusty@rustcorp.com.au> wrote:

> > That then adds 5 bytes to the magic string. Is that really so bad?
>
> Yes, because it's unnecessary.

I'm sorry Rusty, but this argument is disingenuous.

Yes, a length field in the file is unnecessary - BUT SO TOO is scanning! By
this argument, your idea is really so bad too. It's all about the trade off
one chooses to make. I do not accept your chosen trade off[*] as being the
best one.

David

[*] And, yes, it *is* a trade off: you are trading CPU time and permanently
resident kernel code space in order to save a tiny amount of disk
space[**].

[**] Assuming 512 byte blocks and a 5 byte size field, probably fewer than 1%
of modules will expand sufficiently to consume an extra block. Further,
making it a 2-byte binary field would make it even less intrusive, both
in the file and in the module verifier.


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