From patchwork Mon Jul 12 06:08:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 474543 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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 AA586C07E9C for ; Mon, 12 Jul 2021 06:22:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 98D6F61178 for ; Mon, 12 Jul 2021 06:22:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234651AbhGLGY6 (ORCPT ); Mon, 12 Jul 2021 02:24:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:39822 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234648AbhGLGX0 (ORCPT ); Mon, 12 Jul 2021 02:23:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C779D61175; Mon, 12 Jul 2021 06:20:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626070806; bh=p8gdKnwAA5I9CFiD6Qv9vYVinuMxNRyp6lsxSoRm4y0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Gih58o5RByS3kTC0I4Tuina18SK1O43LkDId66CiSasqAIGTZcHxx3lGfOiwVNtVP KfryYHAtlqTb6gdBFsV3IofRIQJzRIr5Qcrh3wbDKQjfQrhblEsCUhuxoAxUXxFCtD r1qmtJmeYxzuUFSwopimh4spqBXPtFMLudytdsfg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matthew Wilcox , Josh Poimboeuf , Sasha Levin Subject: [PATCH 5.4 147/348] kbuild: Fix objtool dependency for OBJECT_FILES_NON_STANDARD_ := n Date: Mon, 12 Jul 2021 08:08:51 +0200 Message-Id: <20210712060720.578975421@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060659.886176320@linuxfoundation.org> References: <20210712060659.886176320@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Josh Poimboeuf [ Upstream commit 8852c552402979508fdc395ae07aa8761aa46045 ] "OBJECT_FILES_NON_STANDARD_vma.o := n" has a dependency bug. When objtool source is updated, the affected object doesn't get re-analyzed by objtool. Peter's new variable-sized jump label feature relies on objtool rewriting the object file. Otherwise the system can fail to boot. That effectively upgrades this minor dependency issue to a major bug. The problem is that variables in prerequisites are expanded early, during the read-in phase. The '$(objtool_dep)' variable indirectly uses '$@', which isn't yet available when the target prerequisites are evaluated. Use '.SECONDEXPANSION:' which causes '$(objtool_dep)' to be expanded in a later phase, after the target-specific '$@' variable has been defined. Fixes: b9ab5ebb14ec ("objtool: Add CONFIG_STACK_VALIDATION option") Fixes: ab3257042c26 ("jump_label, x86: Allow short NOPs") Reported-by: Matthew Wilcox Signed-off-by: Josh Poimboeuf Signed-off-by: Sasha Levin --- scripts/Makefile.build | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 03df22412f86..1261f75cb4e7 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -257,7 +257,8 @@ define rule_as_o_S endef # Built-in and composite module parts -$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE +.SECONDEXPANSION: +$(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE $(call if_changed_rule,cc_o_c) $(call cmd,force_checksrc) @@ -340,7 +341,7 @@ cmd_modversions_S = \ fi endif -$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE +$(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE $(call if_changed_rule,as_o_S) targets += $(filter-out $(subdir-obj-y), $(real-obj-y)) $(real-obj-m) $(lib-y)