From patchwork Thu Jul 7 11:23:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Catalin Marinas X-Patchwork-Id: 9218783 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1FD4460467 for ; Thu, 7 Jul 2016 11:23:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1338928851 for ; Thu, 7 Jul 2016 11:23:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 07BEE28888; Thu, 7 Jul 2016 11:23:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9DD7B28851 for ; Thu, 7 Jul 2016 11:23:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752046AbcGGLXa (ORCPT ); Thu, 7 Jul 2016 07:23:30 -0400 Received: from foss.arm.com ([217.140.101.70]:35663 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751567AbcGGLX3 (ORCPT ); Thu, 7 Jul 2016 07:23:29 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 96EBD28; Thu, 7 Jul 2016 04:24:28 -0700 (PDT) Received: from e104818-lin.cambridge.arm.com (e104818-lin.cambridge.arm.com [10.1.203.148]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0AA763F213; Thu, 7 Jul 2016 04:23:27 -0700 (PDT) Date: Thu, 7 Jul 2016 12:23:25 +0100 From: Catalin Marinas To: Kevin Brodsky Cc: Michal Marek , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org Subject: Re: [PATCH RESEND] arm64: fix vdso-offsets.h dependency Message-ID: <20160707112325.GB27180@e104818-lin.cambridge.arm.com> References: <1463071155-7435-1-git-send-email-kevin.brodsky@arm.com> <20160706175739.GB22615@e104818-lin.cambridge.arm.com> <20160707102601.GA27180@e104818-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160707102601.GA27180@e104818-lin.cambridge.arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Thu, Jul 07, 2016 at 11:26:01AM +0100, Catalin Marinas wrote: > On Wed, Jul 06, 2016 at 06:57:39PM +0100, Catalin Marinas wrote: > > On Thu, May 12, 2016 at 05:39:15PM +0100, Kevin Brodsky wrote: > > > +# We need to generate vdso-offsets.h before compiling certain files in kernel/. > > > +# In order to do that, we should use the archprepare target, but we can't since > > > +# asm-offsets.h is included in some files used to generate vdso-offsets.h, and > > > +# asm-offsets.h is built in prepare0, for which archprepare is a dependency. > > > +# Therefore we need to generate the header after prepare0 has been made, hence > > > +# this hack. > > > +prepare: vdso_prepare > > > +vdso_prepare: prepare0 > > > + $(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso include/generated/vdso-offsets.h > > > > This indeed looks dodgy. I'm not sure about the makefile rules but would > > the above override the "prepare" target in the top Makefile? > > > > I think a dependency problem we have is that arch/arm64/kernel/signal.o > > depends on include/generated/vdso-offsets.h. However, we don't have any > > target for the latter, only for > > $(objtree)arch/arm64/kernel/vdso/vdso-offsets.h which no-one is > > including. Because of this, we have a fake dependency in > > arch/arm64/kernel/Makefile. > > > > -----------8<------------------------- > > diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile > > index 7700c0c23962..9bdacbf59091 100644 > > --- a/arch/arm64/kernel/Makefile > > +++ b/arch/arm64/kernel/Makefile > > @@ -55,5 +55,4 @@ head-y := head.o > > extra-y += $(head-y) vmlinux.lds > > > > # vDSO - this must be built first to generate the symbol offsets > > -$(call objectify,$(arm64-obj-y)): $(obj)/vdso/vdso-offsets.h > > -$(obj)/vdso/vdso-offsets.h: $(obj)/vdso > > +$(objtree)/include/generated/vdso-offsets.h: $(obj)/vdso > > This didn't work either. Basically, when building > arch/arm64/kernel/signal.o for example, it doesn't figure out that > vdso-offsets.h has additional dependencies like the vdso.so.dbg so that > it builds the vdso object first. I'll look for a little longer, maybe I > find a better workaround. If I also add the patch below, it works fine but I'm not sure we can guarantee that kbuild first dives into subdirectories with a parallel build: To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -49,11 +49,7 @@ arm64-obj-$(CONFIG_HIBERNATION) += hibernate.o hibernate-asm.o arm64-obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o \ cpu-reset.o -obj-y += $(arm64-obj-y) vdso/ +obj-y += vdso/ $(arm64-obj-y) obj-m += $(arm64-obj-m) head-y := head.o extra-y += $(head-y) vmlinux.lds -- Catalin --