From patchwork Mon May 31 13:13:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 451265 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 48ECFC47083 for ; Mon, 31 May 2021 13:29:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2CA4861582 for ; Mon, 31 May 2021 13:29:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232287AbhEaNbW (ORCPT ); Mon, 31 May 2021 09:31:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:33248 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232453AbhEaN3T (ORCPT ); Mon, 31 May 2021 09:29:19 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C201B61415; Mon, 31 May 2021 13:22:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1622467353; bh=/s/rwubZx/ifd+zZhHoxLC9s4wnjjK1FQfwAWDavSB0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rrDgFFkLysDJ69xkNQuZuTVZ1LF5SltZ0q53JtZTYWZZ61625LfF45BWOPr6H3NPq 5qXV740ulNosmG0HFGUipNUvqYfrFiccJxqQfUBwg0miK6hCBOKDZxBzUT4lFno3Wv I4w7YzU4yg56+s6Rd9uoO40I8youPXt8JxwHmYwc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Adrian Hunter , Andi Kleen , Jiri Olsa , Arnaldo Carvalho de Melo Subject: [PATCH 4.19 007/116] perf intel-pt: Fix sample instruction bytes Date: Mon, 31 May 2021 15:13:03 +0200 Message-Id: <20210531130640.390800881@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210531130640.131924542@linuxfoundation.org> References: <20210531130640.131924542@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Adrian Hunter commit c954eb72b31a9dc56c99b450253ec5b121add320 upstream. The decoder reports the current instruction if it was decoded. In some cases the current instruction is not decoded, in which case the instruction bytes length must be set to zero. Ensure that is always done. Note perf script can anyway get the instruction bytes for any samples where they are not present. Also note, that there is a redundant "ptq->insn_len = 0" statement which is not removed until a subsequent patch in order to make this patch apply cleanly to stable branches. Example: A machne that supports TSX is required. It will have flag "rtm". Kernel parameter tsx=on may be required. # for w in `cat /proc/cpuinfo | grep -m1 flags `;do echo $w | grep rtm ; done rtm Test program: #include #include int main() { int x = 0; if (_xbegin() == _XBEGIN_STARTED) { x = 1; _xabort(1); } else { printf("x = %d\n", x); } return 0; } Compile with -mrtm i.e. gcc -Wall -Wextra -mrtm xabort.c -o xabort Record: perf record -e intel_pt/cyc/u --filter 'filter main @ ./xabort' ./xabort Before: # perf script --itrace=xe -F+flags,+insn,-period --xed --ns xabort 1478 [007] 92161.431348581: transactions: x 400b81 main+0x14 (/root/xabort) mov $0xffffffff, %eax xabort 1478 [007] 92161.431348624: transactions: tx abrt 400b93 main+0x26 (/root/xabort) mov $0xffffffff, %eax After: # perf script --itrace=xe -F+flags,+insn,-period --xed --ns xabort 1478 [007] 92161.431348581: transactions: x 400b81 main+0x14 (/root/xabort) xbegin 0x6 xabort 1478 [007] 92161.431348624: transactions: tx abrt 400b93 main+0x26 (/root/xabort) xabort $0x1 Fixes: faaa87680b25d ("perf intel-pt/bts: Report instruction bytes and length in sample") Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: Jiri Olsa Cc: stable@vger.kernel.org Link: http://lore.kernel.org/lkml/20210519074515.9262-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman --- tools/perf/util/intel-pt.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/tools/perf/util/intel-pt.c +++ b/tools/perf/util/intel-pt.c @@ -505,8 +505,10 @@ static int intel_pt_walk_next_insn(struc *ip += intel_pt_insn->length; - if (to_ip && *ip == to_ip) + if (to_ip && *ip == to_ip) { + intel_pt_insn->length = 0; goto out_no_cache; + } if (*ip >= al.map->end) break; @@ -893,6 +895,7 @@ static void intel_pt_set_pid_tid_cpu(str static void intel_pt_sample_flags(struct intel_pt_queue *ptq) { + ptq->insn_len = 0; if (ptq->state->flags & INTEL_PT_ABORT_TX) { ptq->flags = PERF_IP_FLAG_BRANCH | PERF_IP_FLAG_TX_ABORT; } else if (ptq->state->flags & INTEL_PT_ASYNC) {