linux-kernel - Re: [PATCH -tip 0/6 V4] tracing: kprobe-based event tracer

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: <20090403142325.GA14932@elte.hu>
Date:	Fri, 3 Apr 2009 16:23:25 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Masami Hiramatsu <mhiramat@...hat.com>
Cc:	Avi Kivity <avi@...hat.com>, "H. Peter Anvin" <hpa@...or.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Ananth N Mavinakayanahalli <ananth@...ibm.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Andi Kleen <andi@...stfloor.org>,
	Jim Keniston <jkenisto@...ibm.com>, kvm@...r.kernel.org,
	systemtap-ml <systemtap@...rces.redhat.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Vegard Nossum <vegard.nossum@...il.com>
Subject: Re: [PATCH -tip 0/6 V4] tracing: kprobe-based event tracer


* Masami Hiramatsu <mhiramat@...hat.com> wrote:

> Hmm, I'd like to know actually kvm aims to emulate all kinds of 
> instructions. If so, I might find some bugs in x86_emulate.c. 
> However, I don't know all bugs. To find all of them, we have to 
> port x86_emulate.c to user-space, decode binaries with it, and 
> compare its output with another decoder, as Jim had done with 
> insn.c.
> 
> https://www.redhat.com/archives/utrace-devel/2009-March/msg00031.html

btw., i'd suggest we put a build time check for this into the kernel 
version as well. For example to decode the vmlinux via objdump, run 
it through your decoder as well and compare the results. Put under a 
CONFIG_DEBUG_X86_DECODER_TEST kind of (deault-off) build-time 
self-test.

This would ensure that the kernel we are running is fully supported 
by the decoder - even as GCC/GAS starts using new instructions, etc. 

How does this sound to you?

	Ingo
--
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/