linux-kernel - Re: [PATCH 1/3] perf/x86/intel: output LBR support statement after validation

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: <20160608090854.GD9646@tassilo.jf.intel.com>
Date:	Wed, 8 Jun 2016 02:08:54 -0700
From:	Andi Kleen <ak@...ux.intel.com>
To:	Stephane Eranian <eranian@...gle.com>
Cc:	David Carrillo-Cisneros <davidcc@...gle.com>,
	LKML <linux-kernel@...r.kernel.org>,
	"x86@...nel.org" <x86@...nel.org>, Ingo Molnar <mingo@...hat.com>,
	"Yan, Zheng" <zheng.z.yan@...el.com>,
	Kan Liang <kan.liang@...el.com>,
	Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH 1/3] perf/x86/intel: output LBR support statement after
 validation

> Ok, so you're saying that syscall and int are not causing LBR callstack to
> record an entry. If that is the case, then a rfi should not cause a pop of the
> last LBR entry. Is that right?

rfi = ?

But likely yes. There shouldn't be any ring 0 branches in the callstack LBR,
as long as the patch forcing it to ring 3 is still there.

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only