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=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 9725FC35254 for ; Sat, 8 Feb 2020 18:36:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D74420733 for ; Sat, 8 Feb 2020 18:36:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728269AbgBHSgh (ORCPT ); Sat, 8 Feb 2020 13:36:37 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33886 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727797AbgBHS3k (ORCPT ); Sat, 8 Feb 2020 13:29:40 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1j0UrI-0003dG-0H; Sat, 08 Feb 2020 18:29:36 +0000 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1j0UrH-000CNy-DI; Sat, 08 Feb 2020 18:29:35 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Namhyung Kim" , "Masami Hiramatsu" , "Arnaldo Carvalho de Melo" , "Jiri Olsa" Date: Sat, 08 Feb 2020 18:20:03 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 064/148] perf probe: Fix to show function entry line as probe-able In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.82-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu commit 91e2f539eeda26ab00bd03fae8dc434c128c85ed upstream. Fix die_walk_lines() to list the function entry line correctly. Since the dwarf_entrypc() does not return the entry pc if the DIE has only range attribute, __die_walk_funclines() fails to list the declaration line (entry line) in that case. To solve this issue, this introduces die_entrypc() which correctly returns the entry PC (the first address range) even if the DIE has only range attribute. With this fix die_walk_lines() shows the function entry line is able to probe correctly. Fixes: 4cc9cec636e7 ("perf probe: Introduce lines walker interface") Signed-off-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Namhyung Kim Link: http://lore.kernel.org/lkml/157190837419.1859.4619125803596816752.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Ben Hutchings --- tools/perf/util/dwarf-aux.c | 24 +++++++++++++++++++++++- tools/perf/util/dwarf-aux.h | 3 +++ 2 files changed, 26 insertions(+), 1 deletion(-) --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -278,6 +278,28 @@ bool die_is_func_def(Dwarf_Die *dw_die) } /** + * die_entrypc - Returns entry PC (the lowest address) of a DIE + * @dw_die: a DIE + * @addr: where to store entry PC + * + * Since dwarf_entrypc() does not return entry PC if the DIE has only address + * range, we have to use this to retrieve the lowest address from the address + * range attribute. + */ +int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr) +{ + Dwarf_Addr base, end; + + if (!addr) + return -EINVAL; + + if (dwarf_entrypc(dw_die, addr) == 0) + return 0; + + return dwarf_ranges(dw_die, 0, &base, addr, &end) < 0 ? -ENOENT : 0; +} + +/** * die_is_func_instance - Ensure that this DIE is an instance of a subprogram * @dw_die: a DIE * @@ -647,7 +669,7 @@ static int __die_walk_funclines(Dwarf_Di /* Handle function declaration line */ fname = dwarf_decl_file(sp_die); if (fname && dwarf_decl_line(sp_die, &lineno) == 0 && - dwarf_entrypc(sp_die, &addr) == 0) { + die_entrypc(sp_die, &addr) == 0) { lw.retval = callback(fname, lineno, addr, data); if (lw.retval != 0) goto done; --- a/tools/perf/util/dwarf-aux.h +++ b/tools/perf/util/dwarf-aux.h @@ -38,6 +38,9 @@ extern int cu_find_lineinfo(Dwarf_Die *c extern int cu_walk_functions_at(Dwarf_Die *cu_die, Dwarf_Addr addr, int (*callback)(Dwarf_Die *, void *), void *data); +/* Get the lowest PC in DIE (including range list) */ +int die_entrypc(Dwarf_Die *dw_die, Dwarf_Addr *addr); + /* Ensure that this DIE is a subprogram and definition (not declaration) */ extern bool die_is_func_def(Dwarf_Die *dw_die);