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 D4CA7C35242 for ; Sat, 8 Feb 2020 18:31:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB4CF2253D for ; Sat, 8 Feb 2020 18:31:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728137AbgBHSbS (ORCPT ); Sat, 8 Feb 2020 13:31:18 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34824 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727976AbgBHS3u (ORCPT ); Sat, 8 Feb 2020 13:29:50 -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-0003do-1g; Sat, 08 Feb 2020 18:29:36 +0000 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1j0UrG-000CNQ-VL; 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" , "Thomas Gleixner" , "Jiri Olsa" , "Masami Hiramatsu" , "Arnaldo Carvalho de Melo" , "David Ahern" , "Peter Zijlstra" Date: Sat, 08 Feb 2020 18:20:01 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 062/148] perf probe: Skip if the function address is 0 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 0ad45b33c58dca60dec7e1fb44766753bc4a7a38 upstream. Skip probes if the entry address of the target function is 0. This can happen when we're handling C++ debuginfo files. E.g. without this fix, below case still fail. ---- $ ./perf probe -x /usr/lib64/libstdc++.so.6 -vD is_open probe-definition(0): is_open symbol:is_open file:(null) line:0 offset:0 return:0 lazy:(null) 0 arguments symbol:catch file:(null) line:0 offset:0 return:0 lazy:(null) symbol:throw file:(null) line:0 offset:0 return:0 lazy:(null) symbol:rethrow file:(null) line:0 offset:0 return:0 lazy:(null) Open Debuginfo file: /usr/lib/debug/usr/lib64/libstdc++.so.6.0.22.debug Try to find probe point from debuginfo. Matched function: is_open [295df] found inline addr: 0x8ca80 Probe point found: is_open+0 found inline addr: 0x8ca70 Probe point found: is_open+0 found inline addr: 0x8ca60 Probe point found: is_open+0 Matched function: is_open [6527f] Matched function: is_open [9fe8a] Probe point found: is_open+0 Matched function: is_open [19710b] found inline addr: 0xecca9 Probe point found: stdio_filebuf+57 found inline addr: 0x0 Probe point found: swap+0 Matched function: is_open [19fc9d] Probe point found: is_open+0 Found 7 probe_trace_events. p:probe_libstdc++/is_open /usr/lib64/libstdc++.so.6.0.22:0x8ca80 p:probe_libstdc++/is_open_1 /usr/lib64/libstdc++.so.6.0.22:0x8ca70 p:probe_libstdc++/is_open_2 /usr/lib64/libstdc++.so.6.0.22:0x8ca60 p:probe_libstdc++/is_open_3 /usr/lib64/libstdc++.so.6.0.22:0xb0ad0 p:probe_libstdc++/is_open_4 /usr/lib64/libstdc++.so.6.0.22:0xecca9 Failed to synthesize probe trace event. Error: Failed to add events. Reason: Invalid argument (Code: -22) ---- This is because some instances have entry_pc == 0 (see 19710b and 19fc9d). With this fix, those are skipped. ---- $ ./perf probe -x /usr/lib64/libstdc++.so.6 -D is_open p:probe_libstdc++/is_open /usr/lib64/libstdc++.so.6.0.22:0x8ca80 p:probe_libstdc++/is_open_1 /usr/lib64/libstdc++.so.6.0.22:0x8ca70 p:probe_libstdc++/is_open_2 /usr/lib64/libstdc++.so.6.0.22:0x8ca60 p:probe_libstdc++/is_open_3 /usr/lib64/libstdc++.so.6.0.22:0xb0ad0 p:probe_libstdc++/is_open_4 /usr/lib64/libstdc++.so.6.0.22:0xecca9 ---- Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Tested-by: Jiri Olsa Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/147464490707.29804.14277897643725143867.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Ben Hutchings --- tools/perf/util/probe-finder.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -871,6 +871,11 @@ static int probe_point_inline_cb(Dwarf_D dwarf_diename(in_die)); return -ENOENT; } + if (addr == 0) { + pr_debug("%s has no valid entry address. skipped.\n", + dwarf_diename(in_die)); + return -ENOENT; + } pf->addr = addr; pf->addr += pp->offset; pr_debug("found inline addr: 0x%jx\n", @@ -912,8 +917,13 @@ static int probe_point_search_cb(Dwarf_D } else if (die_is_func_instance(sp_die)) { /* Instances always have the entry address */ dwarf_entrypc(sp_die, &pf->addr); + /* But in some case the entry address is 0 */ + if (pf->addr == 0) { + pr_debug("%s has no entry PC. Skipped\n", + dwarf_diename(sp_die)); + param->retval = 0; /* Real function */ - if (pp->lazy_line) + } else if (pp->lazy_line) param->retval = find_probe_point_lazy(sp_die, pf); else { pf->addr += pp->offset;