From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933762Ab3ECOmG (ORCPT ); Fri, 3 May 2013 10:42:06 -0400 Received: from mga03.intel.com ([143.182.124.21]:23953 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762442Ab3ECOmD (ORCPT ); Fri, 3 May 2013 10:42:03 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,605,1363158000"; d="scan'208";a="297108268" Date: Fri, 3 May 2013 07:41:57 -0700 From: Andi Kleen To: Peter Zijlstra Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, eranian@google.com Subject: Re: [PATCH 3/3] perf, x86, lbr: Demand proper privileges for PERF_SAMPLE_BRANCH_KERNEL Message-ID: <20130503144157.GQ19487@tassilo.jf.intel.com> References: <20130503121122.931661809@chello.nl> <20130503121256.230745028@chello.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130503121256.230745028@chello.nl> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 03, 2013 at 02:11:25PM +0200, Peter Zijlstra wrote: > We should always have proper privileges when requesting kernel data. > > Cc: Andi Kleen Acked-by: Andi Kleen > --- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c > +++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c > @@ -318,8 +318,11 @@ static void intel_pmu_setup_sw_lbr_filte > if (br_type & PERF_SAMPLE_BRANCH_USER) > mask |= X86_BR_USER; > > - if (br_type & PERF_SAMPLE_BRANCH_KERNEL) > + if (br_type & PERF_SAMPLE_BRANCH_KERNEL) { > + if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) > + return -EACCES; > mask |= X86_BR_KERNEL; > + } > > /* we ignore BRANCH_HV here */ > > > -- ak@linux.intel.com -- Speaking for myself only