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 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 C77A4C433E1 for ; Fri, 15 May 2020 17:22:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A617E20758 for ; Fri, 15 May 2020 17:22:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726694AbgEORW7 (ORCPT ); Fri, 15 May 2020 13:22:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726438AbgEORW6 (ORCPT ); Fri, 15 May 2020 13:22:58 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0FC74C061A0C; Fri, 15 May 2020 10:22:58 -0700 (PDT) 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 1jZe2v-0005Tf-0F; Fri, 15 May 2020 19:22:53 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 8D6861C007F; Fri, 15 May 2020 19:22:52 +0200 (CEST) Date: Fri, 15 May 2020 17:22:52 -0000 From: "tip-bot2 for Sami Tolvanen" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: objtool/core] objtool: optimize add_dead_ends for split sections Cc: Josh Poimboeuf , Sami Tolvanen , "Peter Zijlstra (Intel)" , x86 , LKML In-Reply-To: <20200421220843.188260-3-samitolvanen@google.com> References: <20200421220843.188260-3-samitolvanen@google.com> MIME-Version: 1.0 Message-ID: <158956337243.17951.11031763699409258721.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 objtool/core branch of tip: Commit-ID: 6b5dd716da8fc3aba65e6b7d992dea0cee2f9528 Gitweb: https://git.kernel.org/tip/6b5dd716da8fc3aba65e6b7d992dea0cee2f9528 Author: Sami Tolvanen AuthorDate: Tue, 21 Apr 2020 15:08:43 -07:00 Committer: Peter Zijlstra CommitterDate: Fri, 15 May 2020 10:35:13 +02:00 objtool: optimize add_dead_ends for split sections Instead of iterating through all instructions to find the last instruction each time .rela.discard.(un)reachable points beyond the section, use find_insn to locate the last instruction by looking at the last bytes of the section instead. Suggested-by: Josh Poimboeuf Signed-off-by: Sami Tolvanen Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20200421220843.188260-3-samitolvanen@google.com --- tools/objtool/check.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 196a551..6b2b458 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -322,6 +322,19 @@ err: return ret; } +static struct instruction *find_last_insn(struct objtool_file *file, + struct section *sec) +{ + struct instruction *insn = NULL; + unsigned int offset; + unsigned int end = (sec->len > 10) ? sec->len - 10 : 0; + + for (offset = sec->len - 1; offset >= end && !insn; offset--) + insn = find_insn(file, sec, offset); + + return insn; +} + /* * Mark "ud2" instructions and manually annotated dead ends. */ @@ -330,7 +343,6 @@ static int add_dead_ends(struct objtool_file *file) struct section *sec; struct rela *rela; struct instruction *insn; - bool found; /* * By default, "ud2" is a dead end unless otherwise annotated, because @@ -356,15 +368,8 @@ static int add_dead_ends(struct objtool_file *file) if (insn) insn = list_prev_entry(insn, list); else if (rela->addend == rela->sym->sec->len) { - found = false; - list_for_each_entry_reverse(insn, &file->insn_list, list) { - if (insn->sec == rela->sym->sec) { - found = true; - break; - } - } - - if (!found) { + insn = find_last_insn(file, rela->sym->sec); + if (!insn) { WARN("can't find unreachable insn at %s+0x%x", rela->sym->sec->name, rela->addend); return -1; @@ -398,15 +403,8 @@ reachable: if (insn) insn = list_prev_entry(insn, list); else if (rela->addend == rela->sym->sec->len) { - found = false; - list_for_each_entry_reverse(insn, &file->insn_list, list) { - if (insn->sec == rela->sym->sec) { - found = true; - break; - } - } - - if (!found) { + insn = find_last_insn(file, rela->sym->sec); + if (!insn) { WARN("can't find reachable insn at %s+0x%x", rela->sym->sec->name, rela->addend); return -1;