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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 3DE1CC432C0 for ; Tue, 19 Nov 2019 16:58:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16A0722400 for ; Tue, 19 Nov 2019 16:58:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728712AbfKSQ5N (ORCPT ); Tue, 19 Nov 2019 11:57:13 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:52874 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728657AbfKSQ5J (ORCPT ); Tue, 19 Nov 2019 11:57:09 -0500 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iX6o9-0007P8-Fj; Tue, 19 Nov 2019 17:56:53 +0100 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id CB1C51C19D1; Tue, 19 Nov 2019 17:56:48 +0100 (CET) Date: Tue, 19 Nov 2019 16:56:48 -0000 From: "tip-bot2 for Masami Hiramatsu" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: perf/core] perf probe: Show correct statement line number by perf probe -l Cc: Arnaldo Carvalho de Melo , Masami Hiramatsu , Namhyung Kim , Ravi Bangoria , "Steven Rostedt (VMware)" , Tom Zanussi , Ingo Molnar , Borislav Petkov , linux-kernel@vger.kernel.org In-Reply-To: <157406471067.24476.17463149618465494448.stgit@devnote2> References: <157406471067.24476.17463149618465494448.stgit@devnote2> MIME-Version: 1.0 Message-ID: <157418260878.12247.9502844079335473718.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the perf/core branch of tip: Commit-ID: 57f95bf5f88295612871c36cb0de5069e50570f8 Gitweb: https://git.kernel.org/tip/57f95bf5f88295612871c36cb0de5069e50570f8 Author: Masami Hiramatsu AuthorDate: Mon, 18 Nov 2019 17:11:50 +09:00 Committer: Arnaldo Carvalho de Melo CommitterDate: Mon, 18 Nov 2019 18:56:27 -03:00 perf probe: Show correct statement line number by perf probe -l The dwarf_getsrc_die() can return the line which is not a statement nor the least line number among the lines which shares same address. This can lead perf probe --list shows incorrect line number for probed address. To fix this, this introduces cu_getsrc_die() which returns only a statement line and which is the least line number (we call it the representive line for an address), and use it in cu_find_lineinfo(). Also, if the given address is the entry address of a real function, cu_find_lineinfo() returns the function declared line number instead of the start line number of the function body. For example, without this change perf probe -l shows incorrect line as below. # perf probe -a kernel_read:2 Added new event: probe:kernel_read (on kernel_read:2) You can now use it in all perf tools, such as: perf record -e probe:kernel_read -aR sleep 1 # perf probe -l probe:kernel_read (on kernel_read:1@linux-5.0.0/fs/read_write.c) With this fix, it shows correct line number as below; # perf probe -l probe:kernel_read (on kernel_read:2@linux-5.0.0/fs/read_write.c) Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Namhyung Kim Cc: Ravi Bangoria Cc: Steven Rostedt (VMware) Cc: Tom Zanussi Link: http://lore.kernel.org/lkml/157406471067.24476.17463149618465494448.stgit@devnote2 Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/dwarf-aux.c | 62 +++++++++++++++++++++++++++++++++--- 1 file changed, 58 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 5544bfb..aa89801 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -59,6 +59,51 @@ const char *cu_get_comp_dir(Dwarf_Die *cu_die) return dwarf_formstring(&attr); } +/* Unlike dwarf_getsrc_die(), cu_getsrc_die() only returns statement line */ +static Dwarf_Line *cu_getsrc_die(Dwarf_Die *cu_die, Dwarf_Addr addr) +{ + Dwarf_Addr laddr; + Dwarf_Lines *lines; + Dwarf_Line *line; + size_t nlines, l, u, n; + bool flag; + + if (dwarf_getsrclines(cu_die, &lines, &nlines) != 0 || + nlines == 0) + return NULL; + + /* Lines are sorted by address, use binary search */ + l = 0; u = nlines - 1; + while (l < u) { + n = u - (u - l) / 2; + line = dwarf_onesrcline(lines, n); + if (!line || dwarf_lineaddr(line, &laddr) != 0) + return NULL; + if (addr < laddr) + u = n - 1; + else + l = n; + } + /* Going backward to find the lowest line */ + do { + line = dwarf_onesrcline(lines, --l); + if (!line || dwarf_lineaddr(line, &laddr) != 0) + return NULL; + } while (laddr == addr); + l++; + /* Going foward to find the statement line */ + do { + line = dwarf_onesrcline(lines, l++); + if (!line || dwarf_lineaddr(line, &laddr) != 0 || + dwarf_linebeginstatement(line, &flag) != 0) + return NULL; + if (laddr > addr) + return NULL; + } while (!flag); + + return line; +} + /** * cu_find_lineinfo - Get a line number and file name for given address * @cu_die: a CU DIE @@ -72,17 +117,26 @@ int cu_find_lineinfo(Dwarf_Die *cu_die, unsigned long addr, const char **fname, int *lineno) { Dwarf_Line *line; - Dwarf_Addr laddr; + Dwarf_Die die_mem; + Dwarf_Addr faddr; - line = dwarf_getsrc_die(cu_die, (Dwarf_Addr)addr); - if (line && dwarf_lineaddr(line, &laddr) == 0 && - addr == (unsigned long)laddr && dwarf_lineno(line, lineno) == 0) { + if (die_find_realfunc(cu_die, (Dwarf_Addr)addr, &die_mem) + && die_entrypc(&die_mem, &faddr) == 0 && + faddr == addr) { + *fname = dwarf_decl_file(&die_mem); + dwarf_decl_line(&die_mem, lineno); + goto out; + } + + line = cu_getsrc_die(cu_die, (Dwarf_Addr)addr); + if (line && dwarf_lineno(line, lineno) == 0) { *fname = dwarf_linesrc(line, NULL, NULL); if (!*fname) /* line number is useless without filename */ *lineno = 0; } +out: return *lineno ?: -ENOENT; }