From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: linux-next: build failure after merge of the kspp tree Date: Fri, 27 Jul 2018 14:27:42 +0100 Message-ID: <20180727132742.GB28549@arm.com> References: <20180727190207.7ce1c9b0@canb.auug.org.au> <20180727190647.3525f5f7@canb.auug.org.au> <20180727205511.7c0f2e62@canb.auug.org.au> <20180727125522.GA6173@arm.com> <20180727130106.GB6173@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180727130106.GB6173@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Stephen Rothwell Cc: Kees Cook , Linux-Next Mailing List , Linux Kernel Mailing List , Alexander Popov , Catalin Marinas , Laura Abbott List-Id: linux-next.vger.kernel.org On Fri, Jul 27, 2018 at 02:01:06PM +0100, Will Deacon wrote: > On Fri, Jul 27, 2018 at 01:55:22PM +0100, Will Deacon wrote: > > On Fri, Jul 27, 2018 at 08:55:11PM +1000, Stephen Rothwell wrote: > > > On Fri, 27 Jul 2018 19:06:47 +1000 Stephen Rothwell wrote: > > > > > > > > On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell wrote: > > > > > > > > > > After merging the kspp tree, today's linux-next build (x86_64 > > > > > allmodconfig) failed like this: > > > > > > > > > > cc1: error: plugin stackleak_plugin should be specified before -fplugin-arg-stackleak_plugin-disable in the command line > > > > > > > > > > Maybe caused by commit > > > > > > > > > > a8b9eaddb9c0 ("gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack") > > > > > > > > > > I have used the kspp tree from next-20180726 for today. > > > > > > > > Well, that obviously didn't work since the tree hasn't changed for a > > > > few days. > > > > > > > > I can't see what has interacted to make this happen, so I have dropped > > > > the kspp tree for today. > > > > > > Actually, it may have been caused by commit > > > > > > 0b3e336601b8 ("arm64: Add support for STACKLEAK gcc plugin") > > > > > > from the arm64 tree. > > > > Thanks, Stephen. I managed to reproduce this by merging for-next/kspp from > > Kees's tree and for-next/core from the arm64 tree. The failure happens when > > building the EFI stub, so the commit you mention above is almost certainly > > the culprit. > > > > We build the stub with the following GCC invocation: > > > > gcc -Wp,-MD,drivers/firmware/efi/libstub/.efi-stub-helper.o.d -nostdinc -isystem /usr/lib/gcc/x86_64-linux-gnu/4.9/include -I./arch/x86/include -I./arch/x86/include/generated -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h -include ./include/linux/compiler_types.h -D__KERNEL__ -mcmodel=small -m64 -D__KERNEL__ -O2 -fPIC -fno-strict-aliasing -mno-red-zone -mno-mmx -mno-sse -fshort-wchar -DDISABLE_BRANCH_PROFILING -D__NO_FORTIFY -ffreestanding -fno-stack-protector -fplugin-arg-stackleak_plugin-disable -fno-builtin -DKBUILD_BASENAME='"efi_stub_helper"' -DKBUILD_MODNAME='"efi_stub_helper"' -c -o drivers/firmware/efi/libstub/.tmp_efi-stub-helper.o drivers/firmware/efi/libstub/ef i-stub-helper.c > > > > so given that we're not passing any -fplugin= option anyway (because we > > override KBUILD_CFLAGS for the stub), I don't understand why we need > > to the disable option at all. > > > > Laura? > > ... ah, but arm and arm64 inherit the old KBUILD_CFLAGS via the > cflags-$(CONFIG_ARM64) and cflags-$(CONFIG_ARM) definitions, so they > would be the places where we need to disable the plugin. i.e. something like the diff below. Will --->8 diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 25dd2a14560d..f3700fe08908 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -11,9 +11,11 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ -O2 \ -fPIC -fno-strict-aliasing -mno-red-zone \ -mno-mmx -mno-sse -fshort-wchar -cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie +cflags-$(CONFIG_ARM64) := $(subst -pg,,$(KBUILD_CFLAGS)) -fpie \ + $(DISABLE_STACKLEAK_PLUGIN) cflags-$(CONFIG_ARM) := $(subst -pg,,$(KBUILD_CFLAGS)) \ - -fno-builtin -fpic -mno-single-pic-base + -fno-builtin -fpic -mno-single-pic-base \ + $(DISABLE_STACKLEAK_PLUGIN) cflags-$(CONFIG_EFI_ARMSTUB) += -I$(srctree)/scripts/dtc/libfdt @@ -21,7 +23,6 @@ KBUILD_CFLAGS := $(cflags-y) -DDISABLE_BRANCH_PROFILING \ -D__NO_FORTIFY \ $(call cc-option,-ffreestanding) \ $(call cc-option,-fno-stack-protector) \ - $(DISABLE_STACKLEAK_PLUGIN) GCOV_PROFILE := n KASAN_SANITIZE := n