From patchwork Mon Jul 12 06:05:45 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: 474017 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 90604C11F6B for ; Mon, 12 Jul 2021 07:09:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 75C4761151 for ; Mon, 12 Jul 2021 07:09:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240510AbhGLHME (ORCPT ); Mon, 12 Jul 2021 03:12:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:41260 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244186AbhGLHK3 (ORCPT ); Mon, 12 Jul 2021 03:10:29 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AED52613D7; Mon, 12 Jul 2021 07:07:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626073627; bh=kDZcUNlg8Zo7TUb2wJFOiS67BH/jS2vB68YPXGZ4zbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BTIwR89y6D23htOvfswrlL5fB/62377u3P4KUb2DFHiab07UDjtkmuGB44GX9hT6V SzgoajuBNBoir8+AJOYqz/vhpAsXTNv+JlCip3OVNM3VnX1PfzDnRGuYNj35zAafyv 3uD1ZDViO5j7KkPPiPJ8UgR9wzJRxx/uNpb5haAM= 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 5.12 262/700] kbuild: Fix objtool dependency for OBJECT_FILES_NON_STANDARD_ := n Date: Mon, 12 Jul 2021 08:05:45 +0200 Message-Id: <20210712061004.052317180@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060924.797321836@linuxfoundation.org> References: <20210712060924.797321836@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 1b6094a13034..73701d637ed5 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -267,7 +267,8 @@ 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) $$(objtool_dep) FORCE $(call if_changed_rule,cc_o_c) $(call cmd,force_checksrc) @@ -348,7 +349,7 @@ cmd_modversions_S = \ fi endif -$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE +$(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE $(call if_changed_rule,as_o_S) targets += $(filter-out $(subdir-builtin), $(real-obj-y))