From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033545AbeBOOtJ convert rfc822-to-8bit (ORCPT ); Thu, 15 Feb 2018 09:49:09 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:43860 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1033102AbeBOOtD (ORCPT ); Thu, 15 Feb 2018 09:49:03 -0500 Date: Thu, 15 Feb 2018 20:18:51 +0530 From: "Naveen N. Rao" Subject: Re: [PATCH 9/9] perf tests: Use arch__compare_symbol_names to compare symbols To: Arnaldo Carvalho de Melo , Jiri Olsa Cc: Alexander Shishkin , Peter Zijlstra , David Ahern , lkml , Ingo Molnar , Namhyung Kim , Ravi Bangoria , Sandipan Das References: <20180215122635.24029-1-jolsa@kernel.org> <20180215122635.24029-10-jolsa@kernel.org> <20180215142711.GH22818@kernel.org> In-Reply-To: <20180215142711.GH22818@kernel.org> User-Agent: astroid/0.11.0 (https://github.com/astroidmail/astroid) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8BIT X-TM-AS-GCONF: 00 x-cbid: 18021514-0040-0000-0000-0000043411C6 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18021514-0041-0000-0000-000020D6127A Message-Id: <1518705799.8kkjgp6cbr.naveen@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-02-15_06:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802150182 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Arnaldo Carvalho de Melo wrote: > Em Thu, Feb 15, 2018 at 01:26:35PM +0100, Jiri Olsa escreveu: >> The symbol search called by machine__find_kernel_symbol_by_name >> is using internally arch__compare_symbol_names function to compare >> 2 symbol names, because different archs have different ways of >> comparing symbols. Mostly for skipping '.' prefixes and similar. >> >> In test 1 when we try to find matching symbols in kallsyms and >> vmlinux, by address and by symbol name. When either is found >> we compare the pair symbol names by simple strcmp, which is not >> good enough for reasons explained in previous paragraph. >> >> On powerpc this can cause lockup, because even thought we found >> the pair, the compared names are different and don't match >> simple strcmp. Following code path is executed, that leads >> to lockup: > > Added a: > > Fixes: 031b84c407c3 ("perf probe ppc: Enable matching against dot symbols automatically") > > And CCed Naveen, the author of that patch, so that gets notified of this > fix. Thanks! This does fix the test on ppc64 BE. So: Acked-and-Tested-by: Naveen N. Rao - Naveen