Re: [RFC PATCH v2 03/15] khwasan: add CONFIG_KASAN_CLASSIC and CONFIG_KASAN_TAGS

[Ingo Molnar <mingo@kernel.org>]

* Andrey Konovalov <andreyknvl@google.com> wrote:

> This commit splits the current CONFIG_KASAN config option into two:
> 1. CONFIG_KASAN_CLASSIC, that enables the classic KASAN version (the one
>    that exists now);
> 2. CONFIG_KASAN_TAGS, that enables KHWASAN.

Sorry, but this is pretty obscure naming scheme that doesn't explain the primary 
difference between these KASAN models to users: that the first one is a pure 
software implementation and the other is hardware-assisted.

Reminds me of the transparency of galactic buerocracy in "The Hitchhiker's Guide 
to the Galaxy":

  “But look, you found the notice, didn’t you?”
  “Yes,” said Arthur, “yes I did. It was on display in the bottom of a locked filing 
   cabinet stuck in a disused lavatory with a sign on the door saying ‘Beware of the 
   Leopard.” 

I'd suggest something more expressive, such as:

	CONFIG_KASAN
	  CONFIG_KASAN_GENERIC
	  CONFIG_KASAN_HW_ASSIST

or so?

The 'generic' variant will basically run on any CPU. The 'hardware assisted' one 
needs support from the CPU.

The following ones might also work:

   CONFIG_KASAN_HWASSIST
   CONFIG_KASAN_HW_TAGS
   CONFIG_KASAN_HWTAGS

... or simply CONFIG_KASAN_SW/CONFIG_KASAN_HW.

If other types of KASAN hardware acceleration are implemented in the future then 
the CONFIG_KASAN_HW namespace can be extended:

	CONFIG_KASAN_HW_TAGS
	CONFIG_KASAN_HW_KEYS
	etc.

> Both CONFIG_KASAN_CLASSIC and CONFIG_KASAN_CLASSIC support both
> CONFIG_KASAN_INLINE and CONFIG_KASAN_OUTLINE instrumentation modes.

It would be very surprising if that wasn't so!

Or did you mean 'Both CONFIG_KASAN_CLASSIC and CONFIG_KASAN_TAGS'! ;-)

Thanks,

	Ingo
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