linux-kernel - Re: [PATCH 07/12] perf_events: add LBR software filter support for Intel X86

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:	Mon, 10 Oct 2011 08:09:27 +0200
From:	Ingo Molnar <mingo@...e.hu>
To:	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	Stephane Eranian <eranian@...gle.com>,
	Andi Kleen <andi@...stfloor.org>, linux-kernel@...r.kernel.org,
	acme@...hat.com, ming.m.lin@...el.com, robert.richter@....com,
	ravitillo@....gov
Subject: Re: [PATCH 07/12] perf_events: add LBR software filter support for
 Intel X86


* Masami Hiramatsu <masami.hiramatsu.pt@...achi.com> wrote:

> (2011/10/07 20:21), Peter Zijlstra wrote:
> > On Fri, 2011-10-07 at 13:18 +0200, Peter Zijlstra wrote:
> >>> Yeah, depending on the depth of the LBR. But then what happens, you
> >>> decode an instruction that is not what was executed. 
> >>
> >> Right, and Andi's concern is that this might cause our instruction
> >> decoder to blow up, or worse. 
> > 
> > That is, we have a fair confidence that its capable of correctly
> > decoding correct streams, but I understood from Masami that they haven't
> > actually tried feeding it crap.
> 
> OK, I'll do hardening it.

Yes, that's a good idea. Could you perhaps add it to the existing 
build time sanity test we do for the instruction decoder, to feed it 
a sequence of /dev/urandom input or such?

Thanks,

	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/