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 D791CC35242 for ; Sat, 8 Feb 2020 18:36:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BB630217BA for ; Sat, 8 Feb 2020 18:36:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727786AbgBHSgo (ORCPT ); Sat, 8 Feb 2020 13:36:44 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33880 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727789AbgBHS3k (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-0003dE-0G; Sat, 08 Feb 2020 18:29:36 +0000 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1j0UrH-000CO3-HW; 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 , "Arnaldo Carvalho de Melo" , "Namhyung Kim" , "Jiri Olsa" , "Arnaldo Carvalho de Melo" , "Masami Hiramatsu" Date: Sat, 08 Feb 2020 18:20:04 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 065/148] perf probe: Fix wrong address verification 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 07d369857808b7e8e471bbbbb0074a6718f89b31 upstream. Since there are some DIE which has only ranges instead of the combination of entrypc/highpc, address verification must use dwarf_haspc() instead of dwarf_entrypc/dwarf_highpc. Also, the ranges only DIE will have a partial code in different section (e.g. unlikely code will be in text.unlikely as "FUNC.cold" symbol). In that case, we can not use dwarf_entrypc() or die_entrypc(), because the offset from original DIE can be a minus value. Instead, this simply gets the symbol and offset from symtab. Without this patch; # perf probe -D clear_tasks_mm_cpumask:1 Failed to get entry address of clear_tasks_mm_cpumask Error: Failed to add events. And with this patch: # perf probe -D clear_tasks_mm_cpumask:1 p:probe/clear_tasks_mm_cpumask clear_tasks_mm_cpumask+0 p:probe/clear_tasks_mm_cpumask_1 clear_tasks_mm_cpumask+5 p:probe/clear_tasks_mm_cpumask_2 clear_tasks_mm_cpumask+8 p:probe/clear_tasks_mm_cpumask_3 clear_tasks_mm_cpumask+16 p:probe/clear_tasks_mm_cpumask_4 clear_tasks_mm_cpumask+82 Committer testing: I managed to reproduce the above: [root@quaco ~]# perf probe -D clear_tasks_mm_cpumask:1 p:probe/clear_tasks_mm_cpumask _text+919968 p:probe/clear_tasks_mm_cpumask_1 _text+919973 p:probe/clear_tasks_mm_cpumask_2 _text+919976 [root@quaco ~]# But then when trying to actually put the probe in place, it fails if I use :0 as the offset: [root@quaco ~]# perf probe -L clear_tasks_mm_cpumask | head -5 0 void clear_tasks_mm_cpumask(int cpu) 1 { 2 struct task_struct *p; [root@quaco ~]# perf probe clear_tasks_mm_cpumask:0 Probe point 'clear_tasks_mm_cpumask' not found. Error: Failed to add events. [root@quaco The next patch is needed to fix this case. Fixes: 576b523721b7 ("perf probe: Fix probing symbols with optimization suffix") Reported-by: Arnaldo Carvalho de Melo Tested-by: Arnaldo Carvalho de Melo Signed-off-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Namhyung Kim Link: http://lore.kernel.org/lkml/157199318513.8075.10463906803299647907.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -588,34 +588,26 @@ static int convert_to_trace_point(Dwarf_ Dwarf_Addr paddr, bool retprobe, struct probe_trace_point *tp) { - Dwarf_Addr eaddr, highaddr; + Dwarf_Addr eaddr; GElf_Sym sym; const char *symbol; /* Verify the address is correct */ - if (dwarf_entrypc(sp_die, &eaddr) != 0) { - pr_warning("Failed to get entry address of %s\n", - dwarf_diename(sp_die)); - return -ENOENT; - } - if (dwarf_highpc(sp_die, &highaddr) != 0) { - pr_warning("Failed to get end address of %s\n", - dwarf_diename(sp_die)); - return -ENOENT; - } - if (paddr > highaddr) { - pr_warning("Offset specified is greater than size of %s\n", + if (!dwarf_haspc(sp_die, paddr)) { + pr_warning("Specified offset is out of %s\n", dwarf_diename(sp_die)); return -EINVAL; } - /* Get an appropriate symbol from symtab */ + /* Try to get actual symbol name from symtab */ symbol = dwfl_module_addrsym(mod, paddr, &sym, NULL); if (!symbol) { pr_warning("Failed to find symbol at 0x%lx\n", (unsigned long)paddr); return -ENOENT; } + eaddr = sym.st_value; + tp->offset = (unsigned long)(paddr - sym.st_value); tp->address = (unsigned long)paddr; tp->symbol = strdup(symbol);