linux-kernel - Re: [PATCH] Kprobes: Add kprobes smoke tests that run on boot

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

Message-ID: <20080109212103.GB15612@one.firstfloor.org>
Date:	Wed, 9 Jan 2008 22:21:03 +0100
From:	Andi Kleen <andi@...stfloor.org>
To:	Jim Keniston <jkenisto@...ibm.com>
Cc:	Andi Kleen <andi@...stfloor.org>, ananth@...ibm.com,
	akpm@...ux-foundation.org, lkml <linux-kernel@...r.kernel.org>,
	mingo@...e.hu, mhiramat@...hat.com, davem@...emloft.net,
	hskinnemoen@...el.com
Subject: Re: [PATCH] Kprobes: Add kprobes smoke tests that run on boot

On Wed, Jan 09, 2008 at 12:24:00PM -0800, Jim Keniston wrote:
> On Wed, 2008-01-09 at 00:28 +0100, Andi Kleen wrote:
> > > I have no problem with that, but if we want to make it buildable as a
> > > module, the call to get_kprobe() needs to be replaced with some other
> > > gcc-inline-defeating mechanism, or we need to export get_probe().  I
> > 
> > It's still unclear where noinline does not work (do you have details on that? 
> > It sounds a little dubious) ...
> 
> Here's a simplified version of a module we've used to gauge kprobes
> performance.  On my system (i386, 2.6.23-rc8 at the moment, gcc version
> 4.1.2), the module calls the (empty) probed function (probeme) niter
> times, but reports zero probe hits -- indicating probeme was inlined
> even though it was declared noinline.

Yes indeed looks like a gcc bug. Have you reported it?

-Andi
--
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/