From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753869AbdHDX1W (ORCPT ); Fri, 4 Aug 2017 19:27:22 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48364 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753672AbdHDX1T (ORCPT ); Fri, 4 Aug 2017 19:27:19 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Adrian Hunter , Andi Kleen , Arnaldo Carvalho de Melo Subject: [PATCH 4.4 21/91] perf intel-pt: Ensure never to set last_ip when packet count is zero Date: Fri, 4 Aug 2017 16:15:17 -0700 Message-Id: <20170804231556.993442222@linuxfoundation.org> X-Mailer: git-send-email 2.13.4 In-Reply-To: <20170804231555.678888089@linuxfoundation.org> References: <20170804231555.678888089@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Adrian Hunter commit f952eaceb089b691eba7c4e13686e742a8f26bf5 upstream. Intel PT uses IP compression based on the last IP. For decoding purposes, 'last IP' is not updated when a branch target has been suppressed, which is indicated by IPBytes == 0. IPBytes is stored in the packet 'count', so ensure never to set 'last_ip' when packet 'count' is zero. Signed-off-by: Adrian Hunter Cc: Andi Kleen Link: http://lkml.kernel.org/r/1495786658-18063-7-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman --- tools/perf/util/intel-pt-decoder/intel-pt-decoder.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c +++ b/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c @@ -1438,7 +1438,8 @@ static int intel_pt_walk_psbend(struct i case INTEL_PT_FUP: decoder->pge = true; - intel_pt_set_last_ip(decoder); + if (decoder->packet.count) + intel_pt_set_last_ip(decoder); break; case INTEL_PT_MODE_TSX: @@ -1724,8 +1725,9 @@ next: static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder) { - return decoder->have_last_ip || decoder->packet.count == 0 || - decoder->packet.count == 3 || decoder->packet.count == 6; + return decoder->packet.count && + (decoder->have_last_ip || decoder->packet.count == 3 || + decoder->packet.count == 6); } /* Walk PSB+ packets to get in sync. */