linux-kernel - Re: [PATCH] Linux Kernel Markers 0.8 for 2.6.17 (with near jump for i386)

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20060925053940.GA7014@Krystal>
Date:	Mon, 25 Sep 2006 01:39:40 -0400
From:	Mathieu Desnoyers <compudj@...stal.dyndns.org>
To:	Karim Yaghmour <karim@...rsys.com>
Cc:	Martin Bligh <mbligh@...gle.com>,
	"Frank Ch. Eigler" <fche@...hat.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
	prasanna@...ibm.com, Andrew Morton <akpm@...l.org>,
	Ingo Molnar <mingo@...e.hu>, Paul Mundt <lethal@...ux-sh.org>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Jes Sorensen <jes@....com>, Tom Zanussi <zanussi@...ibm.com>,
	Richard J Moore <richardj_moore@...ibm.com>,
	Michel Dagenais <michel.dagenais@...ymtl.ca>,
	Christoph Hellwig <hch@...radead.org>,
	Greg Kroah-Hartman <gregkh@...e.de>,
	Thomas Gleixner <tglx@...utronix.de>,
	William Cohen <wcohen@...hat.com>, ltt-dev@...fik.org,
	systemtap@...rces.redhat.com, Alan Cox <alan@...rguk.ukuu.org.uk>,
	Jeremy Fitzhardinge <jeremy@...p.org>
Subject: Re: [PATCH] Linux Kernel Markers 0.8 for 2.6.17 (with near jump for  i386)

* Karim Yaghmour (karim@...rsys.com) wrote:
> diffing against an LTT tree ...
> 

Ok, I will do the diff against a vanilla kernel, good point.

> > --- /dev/null
> > +++ b/include/asm-alpha/marker.h
> ...
> > --- /dev/null
> > +++ b/include/asm-arm/marker.h
> ...
> > --- /dev/null
> > +++ b/include/asm-arm26/marker.h
> ...
> ...
> 
> Not sure about the need for asm-foo/marker.h if the file contains no
> code at all. If there's going to be one marker.h per arch, it might
> as well have a purpose. So instead of:
> 
> > --- /dev/null
> > +++ b/include/asm-i386/marker.h
> ...
> > +#define ARCH_HAS_MARK_NEAR_JUMP
> 
> and
> 
> > --- /dev/null
> > +++ b/include/linux/marker.h
> ...
> > +#ifndef ARCH_HAS_MARK_NEAR_JUMP
> ...
> 
> Why not just have asm-foo/marker.h either implement the optimization
> or point to an asm-generic/marker.h which contains the non-optimized
> code. No #ifndefs needed.
> 
Ok, good idea.

> > --- /dev/null
> > +++ b/kernel/Kconfig.marker
> ...
> > +config MARK_SYMBOL
> ...
> > +config MARK_JUMP_CALL
> ...
> > +config MARK_JUMP
> ...
> 
> My understanding of Ingo's input is that he'd rather not have this
> multiple options. Either the markers are active or they aren't.
> So ...
> MARK_ACTIVE ... speaks for itself, enables both the markers and
> the set/disable infrastructure. Markers are enabled in their
> optimized per-architecture implementation.
> 
> MARK_FORCE_DIRECT_CALL ... forces all markers to be non-optimized
> (good for embedded systems where the image is in rom/flash and
> can therefore not have runtime binary modifications.) Maybe this
> should depend on CONFIG_EMBEDDED.
> 
> 

Ok, now only :

CONFIG_MARKERS
and
CONFIG_MARKERS_FORCE_DIRECT_CALL (only appears is EMBEDDED is enabled)

I have rewritted almost everything else, I will post a patch soon (currently
cleaning up). It now supports inline function, unrolled loops and multiple
definitions of the same marker.

Supporting inline functions has proven more important than I first thought
because of gcc 4.0+ optimisations where it takes a static-only function and
inline it automatically in the body of the caller. It removes the symbols of the
inlined function when it does that.

My new approach is a separate .markers section, everything is there.

Mathieu

OpenPGP public key:              http://krystal.dyndns.org:8080/key/compudj.gpg
Key fingerprint:     8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68 
-
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/