linux-kernel - Re: start_kernel(): bug: interrupts were enabled early

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]

Message-Id: <20100331233330.1a7357e4.akpm@linux-foundation.org>
Date:	Wed, 31 Mar 2010 23:33:30 -0400
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Christoph Lameter <cl@...ux-foundation.org>,
	Matthew Wilcox <matthew@....cx>,
	Yinghai Lu <yinghai@...nel.org>, Rabin Vincent <rabin@....in>,
	lkml <linux-kernel@...r.kernel.org>, penberg@...helsinki.fi,
	linux-arch@...r.kernel.org
Subject: Re: start_kernel(): bug: interrupts were enabled early

On Wed, 31 Mar 2010 23:26:52 -0700 "H. Peter Anvin" <hpa@...or.com> wrote:

> On 03/31/2010 03:26 PM, Andrew Morton wrote:
> > 
> > Not by adding overhead to every single down_read()/down_write() just to
> > fix a once-off startup problem - that's taking laziness way too far.
> > 
> 
> How much overhead is this on non-x86 architectures (keep in mind x86
> doesn't use this?)
> 

Just a few instructions, I guess.   But we can do it with zero.

And from a design POV, pretending that down_read()/down_write() can be
called with interrupts disabled is daft - they cannot!  Why muck up the
usual code paths with this startup-specific hack?

--
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/