Messages in this thread | | | From | David Howells <> | Subject | Re: Can KEY_DH_OPERATIONS become tristate? (was: Re: Kernel 5.3.0 stuck during boot on Amiga) | Date | Wed, 18 Sep 2019 17:43:45 +0100 |
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Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > > TL;DR: CONFIG_CRYPTO_DH=y is reported to cause boot delays of several > > > minutes on old and slow machines. > > > > Why is it doing that? It doesn't do anything unless it is called, so > > something must be calling it. > > I don't know. Enabling initcall_debug shows that dh_init() takes a very long > time.
Ah... The bit that handles keyctl_dh_compute() doesn't do anything unless asked, but the bit in the crypto layer that does dh does (ie. dh_init()). I guess it's doing some sort of self-test, but I can't see how it effects that. I think you need to consult the author/maintainer of crypto/dh.c.
It might be possible to make CONFIG_KEY_DH_OPERATIONS not depend on CONFIG_CRYPTO_DH and have crypto_alloc_kpp() load the *crypto* part on demand. Failing that, I can look into demand-loading keyctl operations.
David
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