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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 62299C433B4 for ; Fri, 16 Apr 2021 20:38:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3731D613CD for ; Fri, 16 Apr 2021 20:38:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343665AbhDPUjQ (ORCPT ); Fri, 16 Apr 2021 16:39:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235719AbhDPUjP (ORCPT ); Fri, 16 Apr 2021 16:39:15 -0400 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BE4CC061574 for ; Fri, 16 Apr 2021 13:38:49 -0700 (PDT) Received: by mail-qv1-xf49.google.com with SMTP id w3-20020a05621412e3b029019a7b97dd69so4951342qvv.14 for ; Fri, 16 Apr 2021 13:38:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=RbFM/FOV0/3txgisl3034f4RrM8GnTQruaePZt0Evbk=; b=f7Bw46plZOqlptGDXST+MXI1hXmLkbQvqIezCVQGQqI4O5mhkaRHCID1vyZcdPONT3 jx8yEYK7mIJZXw/SCKURxP3wAK5L4o2KyTJD2LFYiL563Y5zofxqEHaKqSWqo+hay+LB z3MYRqy6T3UyLWZy/O3/fhDwMg2PJeVsUP5cjdUgB7pFaWj030kAUPnYmtuWfSHvOk9z AeVa3xvxQ+dGCZVN4QKtTSnobHUDAzaINOlnc/arbM6EXDg5GO+mhurjQe/xFj0Jqykn S8iV/y2tecn9ldXNpCyI99vVbhC7WyrCQw/o8t7uQeOdkTQEw/9//8k/gATMWz7uHIyF 1yhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=RbFM/FOV0/3txgisl3034f4RrM8GnTQruaePZt0Evbk=; b=fZ46+EXH0UBqpR8GsEAu2Fuef4uQ3HyeOhZc/FIdfQKdYSYUezcXhkMMQIf1Xc+OhY 8z+16u2jq70sYrVSp6eKeVKAC8K+BClqPVmokxMdpflyzPASvf1++TD8uOlCTByW4s+h /pvM17GNY9cIEgwmPOYvaZyMcVGP7T6s08VAwGLYW+SDbNf2mPRL3nRU2CgjVZEMFmWP fg2eEx4S5T8hx4G7OCait0SOoE4P6tALBC4YaFh4vGQZw36hozl2TiZGFLLo7LvC0sPT jl/rUSniHX10aPv6M1fi1IuV2egEgCOhCDh9C2zEgwVhK1C/sbttdiyYxZls8JcQJxJr mjAA== X-Gm-Message-State: AOAM532iOmdbXSKIuKDzsE9rF5dg/MuS/m15glyrmADsdePNyvuJYs2n aaa5Wz4G5ecfkCWef3piGmUCIdAeUyQ/tP/NopQ= X-Google-Smtp-Source: ABdhPJx14/HIHrgP+PDvi3GMAUmLbEk0HIqe60qxMsDGjOaXLdLsX3bhei5pkhEttzRftHK0AOKlKm8rbOh7gvJ0+zc= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:e262:3d8e:cbf:6164]) (user=samitolvanen job=sendgmr) by 2002:a05:6214:1d0c:: with SMTP id e12mr10335145qvd.0.1618605528476; Fri, 16 Apr 2021 13:38:48 -0700 (PDT) Date: Fri, 16 Apr 2021 13:38:30 -0700 In-Reply-To: <20210416203844.3803177-1-samitolvanen@google.com> Message-Id: <20210416203844.3803177-2-samitolvanen@google.com> Mime-Version: 1.0 References: <20210416203844.3803177-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.1.368.gbe11c130af-goog Subject: [PATCH 01/15] objtool: Find a destination for jumps beyond the section end From: Sami Tolvanen To: x86@kernel.org Cc: Kees Cook , Josh Poimboeuf , Peter Zijlstra , Nathan Chancellor , Nick Desaulniers , Sedat Dilek , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org With -ffunction-sections, Clang can generate a jump beyond the end of a section when the section ends in an unreachable instruction. If the offset matches the section length, use the last instruction as the jump destination. Signed-off-by: Sami Tolvanen --- tools/objtool/check.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index a0a8ce61cd4d..5fd60e055a5c 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -870,6 +870,10 @@ static int add_jump_destinations(struct objtool_file *file) } insn->jump_dest = find_insn(file, dest_sec, dest_off); + + if (!insn->jump_dest && dest_sec->len == dest_off) + insn->jump_dest = find_last_insn(file, dest_sec); + if (!insn->jump_dest) { /* -- 2.31.1.368.gbe11c130af-goog