Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755874AbaJXHwN (ORCPT ); Fri, 24 Oct 2014 03:52:13 -0400 Received: from mga02.intel.com ([134.134.136.20]:56699 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755446AbaJXHwJ (ORCPT ); Fri, 24 Oct 2014 03:52:09 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,779,1406617200"; d="scan'208";a="595067400" From: Alexander Shishkin To: Peter Zijlstra Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Robert Richter , Frederic Weisbecker , Mike Galbraith , Paul Mackerras , Stephane Eranian , Andi Kleen , kan.liang@intel.com, adrian.hunter@intel.com, acme@infradead.org Subject: Re: [PATCH v5 12/20] x86: perf: intel_pt: Intel PT PMU driver In-Reply-To: <20141022143418.GU12706@worktop.programming.kicks-ass.net> References: <1413207948-28202-1-git-send-email-alexander.shishkin@linux.intel.com> <1413207948-28202-13-git-send-email-alexander.shishkin@linux.intel.com> <20141022143418.GU12706@worktop.programming.kicks-ass.net> User-Agent: Notmuch/0.17+49~gaa57e9d (http://notmuchmail.org) Emacs/24.3.1 (x86_64-pc-linux-gnu) Date: Fri, 24 Oct 2014 10:52:05 +0300 Message-ID: <8738ad3nx6.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Peter Zijlstra writes: > On Mon, Oct 13, 2014 at 04:45:40PM +0300, Alexander Shishkin wrote: >> +static bool pt_event_valid(struct perf_event *event) >> +{ >> + u64 config = event->attr.config; >> + >> + /* admin can set any packet generation parameters */ >> + if (capable(CAP_SYS_ADMIN) && (config & PT_BYPASS_MASK) == config) >> + return true; >> + >> + if ((config & PT_CONFIG_MASK) != config) >> + return false; >> + >> + return true; >> +} > > This seems to suggest PT is available to !priv users, is this right? Yes, that's the intention. PT does CPL-based filtering in hardware and unlike previous attempts at branch tracing, does not leak out-of-context addresses (or any other information for that matter). Regards, -- Alex -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/