Re: [PATCH 2/4] kexec: add CONFING_KEXEC_PURGATORY_SKIP_SIG

[Jason A. Donenfeld]

Hi Albert,

On Mon, Jul 25, 2022 at 04:38:54PM +0800, Albert Huang wrote:
> +config KEXEC_PURGATORY_SKIP_SIG
> +	bool "skip kexec purgatory signature verification"
> +	depends on ARCH_HAS_KEXEC_PURGATORY
> +	help
> +	  this options makes the kexec purgatory do  not signature verification
> +	  which would get hundreds of milliseconds saved during kexec boot. If we can
> +	  confirm that the data of each segment loaded by kexec will not change we may
> +	  enable this option
> +

Some grammar nits here, but actually, wouldn't it be better to make this
depend on some other signature things instead? Like if the parent kernel
actually did a big signature computation, then maybe the purgatory step
is needed, but if it didn't bother, then maybe you can skip it. This
way, you don't need a compile-time option that might change some aspect
of signature verification people might otherwise be relying on.

Jason