Re: [PATCH] cpu/speculation: Warn on unsupported mitigations= parameter

[Ingo Molnar]

* Jiri Kosina <jikos@xxxxxxxxxx> wrote:

> On Thu, 16 May 2019, Geert Uytterhoeven wrote:
> 
> > Currently, if the user specifies an unsupported mitigation strategy on
> > the kernel command line, it will be ignored silently.  The code will
> > fall back to the default strategy, possibly leaving the system more
> > vulnerable than expected.
> 
> Honestly, I am not convinced. We are not doing this for vast majority of 
> other cmdline options either, if for any at all.

That's really a weakness - I've been bitten by this previously: I typoed 
or mis-remembered a command line option and didn't have it while I 
thought I had it.

Our boot-commandline library is pretty user-unfriendly.

Thanks,

	Ingo