From patchwork Thu Jul 7 18:08:10 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Catalin Marinas X-Patchwork-Id: 71615 Delivered-To: patch@linaro.org Received: by 10.140.28.4 with SMTP id 4csp31284qgy; Thu, 7 Jul 2016 11:10:01 -0700 (PDT) X-Received: by 10.98.89.210 with SMTP id k79mr2364392pfj.152.1467915001429; Thu, 07 Jul 2016 11:10:01 -0700 (PDT) Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id bl8si5254529pad.120.2016.07.07.11.10.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 Jul 2016 11:10:01 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) client-ip=2001:1868:205::9; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org designates 2001:1868:205::9 as permitted sender) smtp.mailfrom=linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bLDj6-0004WD-UH; Thu, 07 Jul 2016 18:08:40 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bLDj2-0004Ut-Ev for linux-arm-kernel@lists.infradead.org; Thu, 07 Jul 2016 18:08:37 +0000 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 362AE28; Thu, 7 Jul 2016 11:09:14 -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 64F0F3F21A; Thu, 7 Jul 2016 11:08:13 -0700 (PDT) Date: Thu, 7 Jul 2016 19:08:10 +0100 From: Catalin Marinas To: Kevin Brodsky Subject: Re: [PATCH RESEND] arm64: fix vdso-offsets.h dependency Message-ID: <20160707180810.GD27180@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> <20160707112325.GB27180@e104818-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160707112325.GB27180@e104818-lin.cambridge.arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160707_110836_520127_41566FDB X-CRM114-Status: GOOD ( 25.61 ) X-Spam-Score: -8.3 (--------) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (-8.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [217.140.101.70 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Michal Marek , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patch=linaro.org@lists.infradead.org On Thu, Jul 07, 2016 at 12:23:25PM +0100, Catalin Marinas wrote: > 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: $(obj)/vdso > > > > This didn't work either. Basically, when building > > arch/arm64/kernel/signal.o for example, it doesn't figure out that > > vdso-offsets.h has additional dependencies like the vdso.so.dbg so that > > it builds the vdso object first. I'll look for a little longer, maybe I > > find a better workaround. > > If I also add the patch below, it works fine but I'm not sure we can > guarantee that kbuild first dives into subdirectories with a parallel > build: > > --- a/arch/arm64/kernel/Makefile > +++ b/arch/arm64/kernel/Makefile > @@ -49,11 +49,7 @@ arm64-obj-$(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) This one works "most of the time" but not always. What I found to work reliably (until further notice ;)) is to force the vdso build like below: ----------------------8<---------------------------- ----------------------8<---------------------------- This was my last attempt at solving this. Unless someone has a better idea or thinkg the above doesn't work (or it's uglier than Kevin's original patch) I plan to merge it. Other advantages are that it only generates a single vdso-offets.h file. It also only rebuilds those objects that depend on vdso-offests.h rather than everything under arch/arm64/kernel/ (Kevin's patch was also solving this). -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 7700c0c23962..366e4f26071f 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -55,5 +55,5 @@ 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 + $(Q)$(MAKE) $(build)=$< $@ diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile index b467fd0a384b..238bb2db76be 100644 --- a/arch/arm64/kernel/vdso/Makefile +++ b/arch/arm64/kernel/vdso/Makefile @@ -23,7 +23,7 @@ GCOV_PROFILE := n ccflags-y += -Wl,-shared obj-y += vdso.o -extra-y += vdso.lds vdso-offsets.h +extra-y += vdso.lds ../../../../include/generated/vdso-offsets.h CPPFLAGS_vdso.lds += -P -C -U$(ARCH) # Force dependency (incbin is bad) @@ -42,11 +42,10 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE gen-vdsosym := $(srctree)/$(src)/gen_vdso_offsets.sh quiet_cmd_vdsosym = VDSOSYM $@ define cmd_vdsosym - $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ && \ - cp $@ include/generated/ + $(NM) $< | $(gen-vdsosym) | LC_ALL=C sort > $@ endef -$(obj)/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE +$(objtree)/include/generated/vdso-offsets.h: $(obj)/vdso.so.dbg FORCE $(call if_changed,vdsosym) # Assembly rules for the .S files