linux-next: build failure after merge of the kspp tree

linux-next: build failure after merge of the kspp tree

[Stephen Rothwell]

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Hi Kees,

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.

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build failure after merge of the kspp tree

[Stephen Rothwell]

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Hi all,

On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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.

-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build failure after merge of the kspp tree

[Stephen Rothwell]

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Hi all,

On Fri, 27 Jul 2018 19:06:47 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
>
> On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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.
-- 
Cheers,
Stephen Rothwell

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Re: linux-next: build failure after merge of the kspp tree

[Will Deacon]

On Fri, Jul 27, 2018 at 08:55:11PM +1000, Stephen Rothwell wrote:
> On Fri, 27 Jul 2018 19:06:47 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> > On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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/efi-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?

Will

Re: linux-next: build failure after merge of the kspp tree

[Will Deacon]

On Fri, Jul 27, 2018 at 08:55:11PM +1000, Stephen Rothwell wrote:
> On Fri, 27 Jul 2018 19:06:47 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:
> >
> > On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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/efi-st
 ub-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?

Will

Re: linux-next: build failure after merge of the kspp tree

[Will Deacon]

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 <sfr@canb.auug.org.au> wrote:
> > >
> > > On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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/efi-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.

Will

Re: linux-next: build failure after merge of the kspp tree

[Will Deacon]

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 <sfr@canb.auug.org.au> wrote:
> > >
> > > On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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/efi-
 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.

Will

Re: linux-next: build failure after merge of the kspp tree

[Will Deacon]

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 <sfr@canb.auug.org.au> wrote:
> > > >
> > > > On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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/efi-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

Re: linux-next: build failure after merge of the kspp tree

[Will Deacon]

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 <sfr@canb.auug.org.au> wrote:
> > > >
> > > > On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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

Re: linux-next: build failure after merge of the kspp tree

[Kees Cook]

On Fri, Jul 27, 2018 at 6:27 AM, Will Deacon <will.deacon@arm.com> wrote:
> 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 <sfr@canb.auug.org.au> wrote:
>> > > >
>> > > > On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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/efi-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

Ah! Thanks for tracking this down!

-Kees

-- 
Kees Cook
Pixel Security

Re: linux-next: build failure after merge of the kspp tree

[Stephen Rothwell]

[-- Attachment #1: Type: text/plain, Size: 2644 bytes --]

Hi all,

On Fri, 27 Jul 2018 13:55:22 +0100 Will Deacon <will.deacon@arm.com> 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 <sfr@canb.auug.org.au> wrote:  
> > >
> > > On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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/efi-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?

So today I am just trying reverting that arm64 tree commit.

-- 
Cheers,
Stephen Rothwell

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

Re: linux-next: build failure after merge of the kspp tree

[Laura Abbott]

On 07/30/2018 12:33 AM, Stephen Rothwell wrote:
> Hi all,
> 
> On Fri, 27 Jul 2018 13:55:22 +0100 Will Deacon <will.deacon@arm.com> 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 <sfr@canb.auug.org.au> wrote:
>>>>
>>>> On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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/efi-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?
> 
> So today I am just trying reverting that arm64 tree commit.
> 

It looks like arm and arm64 start from the KBUILD_CFLAGS and
then filter out vs. x86 which just specifies the CFLAGS individually,
hence x86 picking up the disable when there's no plugin at all. This
seems to be the simplest fix unless we want to change arm64 to not
pick up all the KBUILD_CFLAGS to match x86. That seems like a more
involved process though. If this is okay, I can send a patch
that also sticks a comment in there explaining why fixing on arm64
is necessary.

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 25dd2a14560d..31f376279d5c 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -11,7 +11,8 @@ 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
  
@@ -21,7 +22,6 @@ 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

Re: linux-next: build failure after merge of the kspp tree

[Laura Abbott]

On 07/30/2018 12:33 AM, Stephen Rothwell wrote:
> Hi all,
> 
> On Fri, 27 Jul 2018 13:55:22 +0100 Will Deacon <will.deacon@arm.com> 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 <sfr@canb.auug.org.au> wrote:
>>>>
>>>> On Fri, 27 Jul 2018 19:02:07 +1000 Stephen Rothwell <sfr@canb.auug.org.au> 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?
> 
> So today I am just trying reverting that arm64 tree commit.
> 

It looks like arm and arm64 start from the KBUILD_CFLAGS and
then filter out vs. x86 which just specifies the CFLAGS individually,
hence x86 picking up the disable when there's no plugin at all. This
seems to be the simplest fix unless we want to change arm64 to not
pick up all the KBUILD_CFLAGS to match x86. That seems like a more
involved process though. If this is okay, I can send a patch
that also sticks a comment in there explaining why fixing on arm64
is necessary.

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 25dd2a14560d..31f376279d5c 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -11,7 +11,8 @@ 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
  
@@ -21,7 +22,6 @@ 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

Re: linux-next: build failure after merge of the kspp tree

[Will Deacon]

Hi Laura,

On Mon, Jul 30, 2018 at 07:47:52AM -0700, Laura Abbott wrote:
> On 07/30/2018 12:33 AM, Stephen Rothwell wrote:
> >On Fri, 27 Jul 2018 13:55:22 +0100 Will Deacon <will.deacon@arm.com> wrote:
> >>On Fri, Jul 27, 2018 at 08:55:11PM +1000, Stephen Rothwell wrote:
> >>>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/efi-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?
> >
> >So today I am just trying reverting that arm64 tree commit.
> >
> 
> It looks like arm and arm64 start from the KBUILD_CFLAGS and
> then filter out vs. x86 which just specifies the CFLAGS individually,
> hence x86 picking up the disable when there's no plugin at all. This
> seems to be the simplest fix unless we want to change arm64 to not
> pick up all the KBUILD_CFLAGS to match x86. That seems like a more
> involved process though. If this is okay, I can send a patch
> that also sticks a comment in there explaining why fixing on arm64
> is necessary.

Indeed, I posted a very similar patch last week!

https://lore.kernel.org/lkml/CAGXu5jJ=0YBYKkQM3=KZRp1o3fT0yGY6-0UDkkit0WenFM3oDg@mail.gmail.com/T/#m1bd3d2de78e33da4d1f496fd82be7cf088ebaa06

If you send a version with a commit message, I'm happy to pick it up.

Cheers,

Will

Re: linux-next: build failure after merge of the kspp tree

[Will Deacon]

Hi Laura,

On Mon, Jul 30, 2018 at 07:47:52AM -0700, Laura Abbott wrote:
> On 07/30/2018 12:33 AM, Stephen Rothwell wrote:
> >On Fri, 27 Jul 2018 13:55:22 +0100 Will Deacon <will.deacon@arm.com> wrote:
> >>On Fri, Jul 27, 2018 at 08:55:11PM +1000, Stephen Rothwell wrote:
> >>>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/e
 fi-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?
> >
> >So today I am just trying reverting that arm64 tree commit.
> >
> 
> It looks like arm and arm64 start from the KBUILD_CFLAGS and
> then filter out vs. x86 which just specifies the CFLAGS individually,
> hence x86 picking up the disable when there's no plugin at all. This
> seems to be the simplest fix unless we want to change arm64 to not
> pick up all the KBUILD_CFLAGS to match x86. That seems like a more
> involved process though. If this is okay, I can send a patch
> that also sticks a comment in there explaining why fixing on arm64
> is necessary.

Indeed, I posted a very similar patch last week!

https://lore.kernel.org/lkml/CAGXu5jJ=0YBYKkQM3=KZRp1o3fT0yGY6-0UDkkit0WenFM3oDg@mail.gmail.com/T/#m1bd3d2de78e33da4d1f496fd82be7cf088ebaa06

If you send a version with a commit message, I'm happy to pick it up.

Cheers,

Will

[PATCH] efi/libstub: Only disable stackleak plugin for arm64

[Laura Abbott]

arm64 uses the full KBUILD_CFLAGS for building libstub as opposed
to x86 which doesn't. This means that x86 doesn't pick up
the gcc-plugins. We need to disable the stackleak plugin but
doing this unconditionally breaks x86 build since it doesn't
have any plugins. Switch to disabling the stackleak plugin for
arm64 only.

Signed-off-by: Laura Abbott <labbott@redhat.com>
---
 drivers/firmware/efi/libstub/Makefile | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 25dd2a14560d..88c322d7c71e 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -11,7 +11,10 @@ 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
+# arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly
+# disable the stackleak plugin
+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
 
@@ -21,7 +24,6 @@ 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
-- 
2.17.1

Re: [PATCH] efi/libstub: Only disable stackleak plugin for arm64

[Kees Cook]

On Mon, Jul 30, 2018 at 11:31 AM, Laura Abbott <labbott@redhat.com> wrote:
> arm64 uses the full KBUILD_CFLAGS for building libstub as opposed
> to x86 which doesn't. This means that x86 doesn't pick up
> the gcc-plugins. We need to disable the stackleak plugin but
> doing this unconditionally breaks x86 build since it doesn't
> have any plugins. Switch to disabling the stackleak plugin for
> arm64 only.
>
> Signed-off-by: Laura Abbott <labbott@redhat.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

Thanks!

-Kees

> ---
>  drivers/firmware/efi/libstub/Makefile | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
> index 25dd2a14560d..88c322d7c71e 100644
> --- a/drivers/firmware/efi/libstub/Makefile
> +++ b/drivers/firmware/efi/libstub/Makefile
> @@ -11,7 +11,10 @@ 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
> +# arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly
> +# disable the stackleak plugin
> +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
>
> @@ -21,7 +24,6 @@ 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
> --
> 2.17.1
>



-- 
Kees Cook
Pixel Security

Re: [PATCH] efi/libstub: Only disable stackleak plugin for arm64

[Will Deacon]

On Mon, Jul 30, 2018 at 11:31:18AM -0700, Laura Abbott wrote:
> arm64 uses the full KBUILD_CFLAGS for building libstub as opposed
> to x86 which doesn't. This means that x86 doesn't pick up
> the gcc-plugins. We need to disable the stackleak plugin but
> doing this unconditionally breaks x86 build since it doesn't
> have any plugins. Switch to disabling the stackleak plugin for
> arm64 only.
> 
> Signed-off-by: Laura Abbott <labbott@redhat.com>
> ---
>  drivers/firmware/efi/libstub/Makefile | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

Cheers, Laura, I'll pick this up today. I think we'll need the same thing
for 32-bit ARM if/when they enable support for the plugin.

Will

> diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
> index 25dd2a14560d..88c322d7c71e 100644
> --- a/drivers/firmware/efi/libstub/Makefile
> +++ b/drivers/firmware/efi/libstub/Makefile
> @@ -11,7 +11,10 @@ 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
> +# arm64 uses the full KBUILD_CFLAGS so it's necessary to explicitly
> +# disable the stackleak plugin
> +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
>  
> @@ -21,7 +24,6 @@ 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
> -- 
> 2.17.1
> 

Re: linux-next: build failure after merge of the kspp tree

[Will Deacon]

On Mon, Jul 30, 2018 at 05:33:56PM +1000, Stephen Rothwell wrote:
> On Fri, 27 Jul 2018 13:55:22 +0100 Will Deacon <will.deacon@arm.com> wrote:
> > 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/efi-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?
> 
> So today I am just trying reverting that arm64 tree commit.

I've pushed out Laura's fix to the arm64 for-next/core branch, so this
should be resolved in the next next.

Will

Re: linux-next: build failure after merge of the kspp tree

[Will Deacon]

On Mon, Jul 30, 2018 at 05:33:56PM +1000, Stephen Rothwell wrote:
> On Fri, 27 Jul 2018 13:55:22 +0100 Will Deacon <will.deacon@arm.com> wrote:
> > 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?
> 
> So today I am just trying reverting that arm64 tree commit.

I've pushed out Laura's fix to the arm64 for-next/core branch, so this
should be resolved in the next next.

Will

Re: linux-next: build failure after merge of the kspp tree

[Stephen Rothwell]

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Hi Will,

On Tue, 31 Jul 2018 11:09:18 +0100 Will Deacon <will.deacon@arm.com> wrote:
>
> I've pushed out Laura's fix to the arm64 for-next/core branch, so this
> should be resolved in the next next.

Thanks.  I actually applied Laura's patch to today's linux-next as well.

-- 
Cheers,
Stephen Rothwell

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