Messages in this thread | | | Subject | Re: [PATCH 00/23] Crypto keys and module signing | Date | Thu, 31 May 2012 15:11:02 +0100 | From | David Howells <> |
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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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