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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 75527C5519F for ; Fri, 27 Nov 2020 17:36:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3072221534 for ; Fri, 27 Nov 2020 17:36:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZOtUgtWW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731981AbgK0Rgc (ORCPT ); Fri, 27 Nov 2020 12:36:32 -0500 Received: from mail.kernel.org ([198.145.29.99]:36898 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730603AbgK0Rgc (ORCPT ); Fri, 27 Nov 2020 12:36:32 -0500 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7BDDC206CA; Fri, 27 Nov 2020 17:36:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606498591; bh=ZPPJbupxbpXsjev8DgFJhnZBqhC9z8zd29YDNWFaFpA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZOtUgtWWlFZtcTtJyKGU3EAbP4aeDSiMOErMV5bQGmN5S9i5MaqKSMkTjToA+uTUs L/wqT3eKnl+1L/9iBsgVgwXwiHupJsXO5AYAB2uYevCnjbvQFwlVFLQZWLP0xICqLT OZvTKbhdL0is8Tkjspl2fsLb0JuiBR4072dNop4Q= Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 8599240D0D; Fri, 27 Nov 2020 14:36:29 -0300 (-03) Date: Fri, 27 Nov 2020 14:36:29 -0300 From: Arnaldo Carvalho de Melo To: Masami Hiramatsu Cc: Thomas Richter , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Sumanth Korikkar Subject: Re: [PATCH 2/2] perf-probe: Change function definition check due to broken dwarf Message-ID: <20201127173629.GP70905@kernel.org> References: <20201126172849.GE53384@kernel.org> <160645613571.2824037.7441351537890235895.stgit@devnote2> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <160645613571.2824037.7441351537890235895.stgit@devnote2> X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Em Fri, Nov 27, 2020 at 02:48:55PM +0900, Masami Hiramatsu escreveu: > Since some gcc generates a broken DWARF which lacks DW_AT_declaration > attribute from the subprogram DIE of function prototype. > (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97060) > > So, in addition to the DW_AT_declaration check, we also check the > subprogram DIE has DW_AT_inline or actual entry pc. Thanks, applied and tested both patches on a fedora 33 system where previously those tests were failing: Committer testing: # cat /etc/fedora-release Fedora release 33 (Thirty Three) # Before: # perf test vfs_getname 78: Use vfs_getname probe to get syscall args filenames : FAILED! 79: Check open filename arg using perf trace + vfs_getname : FAILED! 81: Add vfs_getname probe to get syscall args filenames : FAILED! # After: # perf test vfs_getname 78: Use vfs_getname probe to get syscall args filenames : Ok 79: Check open filename arg using perf trace + vfs_getname : Ok 81: Add vfs_getname probe to get syscall args filenames : Ok # - Arnaldo > Reported-by: Thomas Richter > Signed-off-by: Masami Hiramatsu > --- > tools/perf/util/dwarf-aux.c | 20 ++++++++++++++++++-- > tools/perf/util/probe-finder.c | 3 +-- > 2 files changed, 19 insertions(+), 4 deletions(-) > > diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c > index 03c1a39c312a..7b2d471a6419 100644 > --- a/tools/perf/util/dwarf-aux.c > +++ b/tools/perf/util/dwarf-aux.c > @@ -356,9 +356,25 @@ bool die_is_signed_type(Dwarf_Die *tp_die) > bool die_is_func_def(Dwarf_Die *dw_die) > { > Dwarf_Attribute attr; > + Dwarf_Addr addr = 0; > + > + if (dwarf_tag(dw_die) != DW_TAG_subprogram) > + return false; > + > + if (dwarf_attr(dw_die, DW_AT_declaration, &attr)) > + return false; > > - return (dwarf_tag(dw_die) == DW_TAG_subprogram && > - dwarf_attr(dw_die, DW_AT_declaration, &attr) == NULL); > + /* > + * DW_AT_declaration can be lost from function declaration > + * by gcc's bug #97060. > + * So we need to check this subprogram DIE has DW_AT_inline > + * or an entry address. > + */ > + if (!dwarf_attr(dw_die, DW_AT_inline, &attr) && > + die_entrypc(dw_die, &addr) < 0) > + return false; > + > + return true; > } > > /** > diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c > index 2c4061035f77..76dd349aa48d 100644 > --- a/tools/perf/util/probe-finder.c > +++ b/tools/perf/util/probe-finder.c > @@ -1885,8 +1885,7 @@ static int line_range_search_cb(Dwarf_Die *sp_die, void *data) > if (lr->file && strtailcmp(lr->file, dwarf_decl_file(sp_die))) > return DWARF_CB_OK; > > - if (die_is_func_def(sp_die) && > - die_match_name(sp_die, lr->function)) { > + if (die_match_name(sp_die, lr->function) && die_is_func_def(sp_die)) { > lf->fname = dwarf_decl_file(sp_die); > dwarf_decl_line(sp_die, &lr->offset); > pr_debug("fname: %s, lineno:%d\n", lf->fname, lr->offset); > -- - Arnaldo