linux-kernel - Re: [all better] Re: regression: massive trouble with fpu rework

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sun, 28 Jun 2015 12:06:38 -0300
From:	Henrique de Moraes Holschuh <hmh@....eng.br>
To:	Mike Galbraith <umgwanakikbuti@...il.com>
Cc:	Ingo Molnar <mingo@...nel.org>, Ingo Molnar <mingo@...e.hu>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [all better] Re: regression: massive trouble with fpu rework

On Sun, 28 Jun 2015, Mike Galbraith wrote:
> > > > > BIOS setting "Limit CPUID Maximum" upsets new fpu code mightily.
> > 
> > Well, it is supposed to disable CPUID levels >= 0x04.  This thing should
> > *NEVER* be enabled, the last operating system that required it to be enabled
> > was Windows 98.
> > 
> > Can/do we override that crap during cpu init?  If we cannot/don't, maybe
> > instead of limping along with CPUID crippled, it would be better to either
> > output a very nasty warning, or outright stop booting [with an appropriate
> > error message] ?
> 
> Why get all upset?  We didn't even notice before, nor did/does that
> other OS.  A casual "BTW, your BIOS sucks.." should suffice, no?

Oh, I am not upset, although I suppose my reply did look like it.  Sorry
about that.

It is just that this kind of breakage should not be subtle if we can help
it, because people will use a crippled system for years without noticing...

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/