From mboxrd@z Thu Jan 1 00:00:00 1970 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=-13.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 22E43C282C8 for ; Mon, 28 Jan 2019 13:35:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ECE002148E for ; Mon, 28 Jan 2019 13:35:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726804AbfA1Nfb (ORCPT ); Mon, 28 Jan 2019 08:35:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33186 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726647AbfA1Nfa (ORCPT ); Mon, 28 Jan 2019 08:35:30 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2BABAC058CB7; Mon, 28 Jan 2019 13:35:30 +0000 (UTC) Received: from krava (unknown [10.40.205.232]) by smtp.corp.redhat.com (Postfix) with SMTP id 4F4C12B9FA; Mon, 28 Jan 2019 13:35:27 +0000 (UTC) Date: Mon, 28 Jan 2019 14:35:26 +0100 From: Jiri Olsa To: Arnaldo Carvalho de Melo Cc: Jiri Olsa , Nick Clifton , lkml , Ingo Molnar , Namhyung Kim , Alexander Shishkin , Peter Zijlstra , Michael Petlan , Masami Hiramatsu Subject: [PATCH] perf tools: Filter out hidden symbols from labels Message-ID: <20190128133526.GD15461@krava> References: <20190115135354.11572-1-jolsa@kernel.org> <960f0b83-a623-67a6-ab55-d56139d10ba2@redhat.com> <20190115173838.GB31411@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190115173838.GB31411@krava> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 28 Jan 2019 13:35:30 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 15, 2019 at 06:38:38PM +0100, Jiri Olsa wrote: > On Tue, Jan 15, 2019 at 04:13:16PM +0000, Nick Clifton wrote: > > Hi Jiri, > > > > > When perf is built with annobin plugin (RHEL8 build) extra symbols > > > are added to its binary: > > > > A bit of background for those wondering why annobin is creating > > these symbols: Annobin is a plugin for gcc that records data > > about how object file were built. It is specifically designed > > to be able to cope with files that are built using multiple > > different sets of optimization options. (Eg because of #pragma > > directives or function specific optimization attributes). It > > generates notes to cover each compiled region of code, and it > > needs the symbols in order to be able to determine exactly which > > areas in a linked binary were compiled with which options. > > > > In the course of developing this plugin I encountered various > > problems with tools not expecting to find extra symbols in a > > binary. Hence I made the symbols local, hidden and with no type. > > It was the best I could do to say "ignore these symbols - they > > are not meant to be seen by anyone but annobin". > > > > > > > + elf_sym__visibility(sym) != STV_HIDDEN; > > > > Just to be awkward, if you are going to ignore STV_HIDDEN > > symbols then you should probably also ignore STV_INTERNAL ones > > as well... Annobin does not generate them, but you never know, > > one day some other tool might create some. > > sounds good, thanks there were no objections for rfc, sending patch thanks, jirka --- When perf is built with annobin plugin (RHEL8 build) extra symbols are added to its binary: # nm perf | grep annobin | head -10 0000000000241100 t .annobin_annotate.c 0000000000326490 t .annobin_annotate.c 0000000000249255 t .annobin_annotate.c_end 00000000003283a8 t .annobin_annotate.c_end 00000000001bce18 t .annobin_annotate.c_end.hot 00000000001bce18 t .annobin_annotate.c_end.hot 00000000001bc3e2 t .annobin_annotate.c_end.unlikely 00000000001bc400 t .annobin_annotate.c_end.unlikely 00000000001bce18 t .annobin_annotate.c.hot 00000000001bce18 t .annobin_annotate.c.hot ... those symbols have no use for report or annotation and should be skipped. Moreover they interfere with dwarf unwind test on ppc arch, where they are mixed with checked symbols and test fails: # perf test dwarf -v 59: Test dwarf unwind : --- start --- test child forked, pid 8515 unwind: .annobin_dwarf_unwind.c:ip = 0x10dba40dc (0x2740dc) ... got: .annobin_dwarf_unwind.c 0x10dba40dc, expecting test__arch_unwind_sample unwind: failed with 'no error' The annobin symbols are defined as NOTYPE/LOCAL/HIDDEN: # readelf -s ./perf | grep annobin | head -1 40: 00000000001bce4f 0 NOTYPE LOCAL HIDDEN 13 .annobin_init.c They can still pass the check for the label symbol. Adding check for HIDDEN and INTERNAL (as suggested by Nick below) visibility and filter out such symbols. > Just to be awkward, if you are going to ignore STV_HIDDEN > symbols then you should probably also ignore STV_INTERNAL ones > as well... Annobin does not generate them, but you never know, > one day some other tool might create some. Link: http://lkml.kernel.org/n/tip-4yuna6qhhg0df3q147cjdyuu@git.kernel.org Signed-off-by: Jiri Olsa --- tools/perf/util/symbol-elf.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 66a84d5846c8..03cb8c6d620a 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -87,6 +87,11 @@ static inline uint8_t elf_sym__type(const GElf_Sym *sym) return GELF_ST_TYPE(sym->st_info); } +static inline uint8_t elf_sym__visibility(const GElf_Sym *sym) +{ + return GELF_ST_VISIBILITY(sym->st_other); +} + #ifndef STT_GNU_IFUNC #define STT_GNU_IFUNC 10 #endif @@ -111,7 +116,9 @@ static inline int elf_sym__is_label(const GElf_Sym *sym) return elf_sym__type(sym) == STT_NOTYPE && sym->st_name != 0 && sym->st_shndx != SHN_UNDEF && - sym->st_shndx != SHN_ABS; + sym->st_shndx != SHN_ABS && + elf_sym__visibility(sym) != STV_HIDDEN && + elf_sym__visibility(sym) != STV_INTERNAL; } static bool elf_sym__filter(GElf_Sym *sym) -- 2.17.2