[PATCH] arch/x86/boot: Don't add the EFI stub to targets

[PATCH] arch/x86/boot: Don't add the EFI stub to targets

[Arvind Sankar]

vmlinux-objs-y is added to targets, which currently means that the EFI
stub gets added to the targets as well. It shouldn't be added since it
is built elsewhere.

This confuses Makefile.build which interprets the EFI stub as a target
	$(obj)/$(objtree)/drivers/firmware/efi/libstub/lib.a
and will create drivers/firmware/efi/libstub/ underneath
arch/x86/boot/compressed, to hold this supposed target, if building
out-of-tree. [0]

Fix this by pulling the stub out of vmlinux-objs-y into efi-obj-y.

[0] See scripts/Makefile.build near the end:
    # Create directories for object files if they do not exist

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
---
 arch/x86/boot/compressed/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 7619742f91c9..5a828fde7a42 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -90,8 +90,8 @@ endif
 
 vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
 
-vmlinux-objs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
 vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
+efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a
 
 # The compressed kernel is built with -fPIC/-fPIE so that a boot loader
 # can place it anywhere in memory and it will still run. However, since
@@ -115,7 +115,7 @@ endef
 quiet_cmd_check-and-link-vmlinux = LD      $@
       cmd_check-and-link-vmlinux = $(cmd_check_data_rel); $(cmd_ld)
 
-$(obj)/vmlinux: $(vmlinux-objs-y) FORCE
+$(obj)/vmlinux: $(vmlinux-objs-y) $(efi-obj-y) FORCE
 	$(call if_changed,check-and-link-vmlinux)
 
 OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
-- 
2.26.2

Re: [PATCH] arch/x86/boot: Don't add the EFI stub to targets

[Ard Biesheuvel]

On Wed, 15 Jul 2020 at 06:26, Arvind Sankar <nivedita@alum.mit.edu> wrote:
>
> vmlinux-objs-y is added to targets, which currently means that the EFI
> stub gets added to the targets as well. It shouldn't be added since it
> is built elsewhere.
>
> This confuses Makefile.build which interprets the EFI stub as a target
>         $(obj)/$(objtree)/drivers/firmware/efi/libstub/lib.a
> and will create drivers/firmware/efi/libstub/ underneath
> arch/x86/boot/compressed, to hold this supposed target, if building
> out-of-tree. [0]
>
> Fix this by pulling the stub out of vmlinux-objs-y into efi-obj-y.
>
> [0] See scripts/Makefile.build near the end:
>     # Create directories for object files if they do not exist
>
> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>

Acked-by: Ard Biesheuvel <ardb@kernel.org>

> ---
>  arch/x86/boot/compressed/Makefile | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
> index 7619742f91c9..5a828fde7a42 100644
> --- a/arch/x86/boot/compressed/Makefile
> +++ b/arch/x86/boot/compressed/Makefile
> @@ -90,8 +90,8 @@ endif
>
>  vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
>
> -vmlinux-objs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
>  vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
> +efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a
>
>  # The compressed kernel is built with -fPIC/-fPIE so that a boot loader
>  # can place it anywhere in memory and it will still run. However, since
> @@ -115,7 +115,7 @@ endef
>  quiet_cmd_check-and-link-vmlinux = LD      $@
>        cmd_check-and-link-vmlinux = $(cmd_check_data_rel); $(cmd_ld)
>
> -$(obj)/vmlinux: $(vmlinux-objs-y) FORCE
> +$(obj)/vmlinux: $(vmlinux-objs-y) $(efi-obj-y) FORCE
>         $(call if_changed,check-and-link-vmlinux)
>
>  OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
> --
> 2.26.2
>

Re: [PATCH] arch/x86/boot: Don't add the EFI stub to targets

[Masahiro Yamada]

On Wed, Jul 15, 2020 at 12:26 PM Arvind Sankar <nivedita@alum.mit.edu> wrote:
>
> vmlinux-objs-y is added to targets, which currently means that the EFI
> stub gets added to the targets as well. It shouldn't be added since it
> is built elsewhere.
>
> This confuses Makefile.build which interprets the EFI stub as a target
>         $(obj)/$(objtree)/drivers/firmware/efi/libstub/lib.a
> and will create drivers/firmware/efi/libstub/ underneath
> arch/x86/boot/compressed, to hold this supposed target, if building
> out-of-tree. [0]
>
> Fix this by pulling the stub out of vmlinux-objs-y into efi-obj-y.
>
> [0] See scripts/Makefile.build near the end:
>     # Create directories for object files if they do not exist
>
> Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
> ---


Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>



>  arch/x86/boot/compressed/Makefile | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
> index 7619742f91c9..5a828fde7a42 100644
> --- a/arch/x86/boot/compressed/Makefile
> +++ b/arch/x86/boot/compressed/Makefile
> @@ -90,8 +90,8 @@ endif
>
>  vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
>
> -vmlinux-objs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a
>  vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
> +efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a
>
>  # The compressed kernel is built with -fPIC/-fPIE so that a boot loader
>  # can place it anywhere in memory and it will still run. However, since
> @@ -115,7 +115,7 @@ endef
>  quiet_cmd_check-and-link-vmlinux = LD      $@
>        cmd_check-and-link-vmlinux = $(cmd_check_data_rel); $(cmd_ld)
>
> -$(obj)/vmlinux: $(vmlinux-objs-y) FORCE
> +$(obj)/vmlinux: $(vmlinux-objs-y) $(efi-obj-y) FORCE
>         $(call if_changed,check-and-link-vmlinux)
>
>  OBJCOPYFLAGS_vmlinux.bin :=  -R .comment -S
> --
> 2.26.2
>


-- 
Best Regards
Masahiro Yamada