Re: [PATCH] BaseTools/tools_def AARCH64 ARM: suppres PIE sections via linker script

[Marcin Wojtas <mw@semihalf.com>]

Hi Ard,

2017-11-21 17:10 GMT+01:00 Ard Biesheuvel <ard.biesheuvel@linaro.org>:
> Recent distro builds of GCC 6 enable PIE linking by default, and allow
> the previous behavior to be restored by passing the -no-pie command line
> argument. This was implemented by commits 1894a7c64c0a and 3380a591232d
> but unfortunately, it turns out that GCC 5 does not support this command
> line argument, and exits with an error.
>
> To avoid the need for yet another toolchain tag, to distinguish between
> GCC 5 and GCC 6, let's use our GCC linker scripts when building objects
> from .aslc files. This will ensure that the extra sections that are added
> by the PIE linker are discarded from the ELF binary, and so they will not
> corrupt the resulting .acpi file.
>
> This reverts
>
> 1894a7c64c0a BaseTools/tools_def AARCH64 ARM: disable PIE linking
> 3380a591232d BaseTools/tools_def AARCH64 ARM: disable PIE linking for .aslc sources
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  BaseTools/Conf/tools_def.template | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
> index aebd7d558633..4d2a3b7dbe56 100755
> --- a/BaseTools/Conf/tools_def.template
> +++ b/BaseTools/Conf/tools_def.template
> @@ -4356,9 +4356,10 @@ DEFINE GCC_IA32_X64_DLINK_COMMON   = DEF(GCC_DLINK_FLAGS_COMMON) --gc-sections
>  DEFINE GCC_ARM_AARCH64_DLINK_COMMON= -Wl,--emit-relocs -nostdlib -Wl,--gc-sections -u $(IMAGE_ENTRY_POINT) -Wl,-e,$(IMAGE_ENTRY_POINT),-Map,$(DEST_DIR_DEBUG)/$(BASE_NAME).map
>  DEFINE GCC_ARM_DLINK_FLAGS         = DEF(GCC_ARM_AARCH64_DLINK_COMMON) -z common-page-size=0x20
>  DEFINE GCC_AARCH64_DLINK_FLAGS     = DEF(GCC_ARM_AARCH64_DLINK_COMMON) -z common-page-size=0x20
> +DEFINE GCC_ARM_AARCH64_ASLDLINK_FLAGS = -Wl,--defsym=PECOFF_HEADER_SIZE=0 DEF(GCC_DLINK2_FLAGS_COMMON) -z common-page-size=0x20
>  DEFINE GCC_IA32_X64_ASLDLINK_FLAGS = DEF(GCC_IA32_X64_DLINK_COMMON) --entry _ReferenceAcpiTable -u $(IMAGE_ENTRY_POINT)
> -DEFINE GCC_ARM_ASLDLINK_FLAGS      = DEF(GCC_ARM_DLINK_FLAGS) -Wl,--entry,ReferenceAcpiTable -u $(IMAGE_ENTRY_POINT)
> -DEFINE GCC_AARCH64_ASLDLINK_FLAGS  = DEF(GCC_AARCH64_DLINK_FLAGS) -Wl,--entry,ReferenceAcpiTable -u $(IMAGE_ENTRY_POINT)
> +DEFINE GCC_ARM_ASLDLINK_FLAGS      = DEF(GCC_ARM_DLINK_FLAGS) -Wl,--entry,ReferenceAcpiTable -u $(IMAGE_ENTRY_POINT) DEF(GCC_ARM_AARCH64_ASLDLINK_FLAGS)
> +DEFINE GCC_AARCH64_ASLDLINK_FLAGS  = DEF(GCC_AARCH64_DLINK_FLAGS) -Wl,--entry,ReferenceAcpiTable -u $(IMAGE_ENTRY_POINT) DEF(GCC_ARM_AARCH64_ASLDLINK_FLAGS)
>  DEFINE GCC_IA32_X64_DLINK_FLAGS    = DEF(GCC_IA32_X64_DLINK_COMMON) --entry _$(IMAGE_ENTRY_POINT) --file-alignment 0x20 --section-alignment 0x20 -Map $(DEST_DIR_DEBUG)/$(BASE_NAME).map
>  DEFINE GCC_IPF_DLINK_FLAGS         = -nostdlib -O2 --gc-sections --dll -static --entry $(IMAGE_ENTRY_POINT) --undefined $(IMAGE_ENTRY_POINT) -Map $(DEST_DIR_DEBUG)/$(BASE_NAME).map
>  DEFINE GCC_IPF_OBJCOPY_FLAGS       = -I elf64-ia64-little -O efi-bsdrv-ia64
> @@ -4494,12 +4495,12 @@ DEFINE GCC5_ARM_CC_FLAGS             = DEF(GCC49_ARM_CC_FLAGS)
>  DEFINE GCC5_ARM_CC_XIPFLAGS          = DEF(GCC49_ARM_CC_XIPFLAGS)
>  DEFINE GCC5_AARCH64_CC_FLAGS         = DEF(GCC49_AARCH64_CC_FLAGS)
>  DEFINE GCC5_AARCH64_CC_XIPFLAGS      = DEF(GCC49_AARCH64_CC_XIPFLAGS)
> -DEFINE GCC5_ARM_DLINK_FLAGS          = DEF(GCC49_ARM_DLINK_FLAGS) -no-pie
> +DEFINE GCC5_ARM_DLINK_FLAGS          = DEF(GCC49_ARM_DLINK_FLAGS)
>  DEFINE GCC5_ARM_DLINK2_FLAGS         = DEF(GCC49_ARM_DLINK2_FLAGS) -Wno-error
> -DEFINE GCC5_AARCH64_DLINK_FLAGS      = DEF(GCC49_AARCH64_DLINK_FLAGS) -no-pie
> +DEFINE GCC5_AARCH64_DLINK_FLAGS      = DEF(GCC49_AARCH64_DLINK_FLAGS)
>  DEFINE GCC5_AARCH64_DLINK2_FLAGS     = DEF(GCC49_AARCH64_DLINK2_FLAGS) -Wno-error
> -DEFINE GCC5_ARM_ASLDLINK_FLAGS       = DEF(GCC49_ARM_ASLDLINK_FLAGS) -no-pie
> -DEFINE GCC5_AARCH64_ASLDLINK_FLAGS   = DEF(GCC49_AARCH64_ASLDLINK_FLAGS) -no-pie
> +DEFINE GCC5_ARM_ASLDLINK_FLAGS       = DEF(GCC49_ARM_ASLDLINK_FLAGS)
> +DEFINE GCC5_AARCH64_ASLDLINK_FLAGS   = DEF(GCC49_AARCH64_ASLDLINK_FLAGS)
>
>  ####################################################################################
>  #
> --

Thanks for the patch - this fixes regression, I observed when building
edk2 with gcc-linaro-5.3.1-2016.05-x86_64_aarch64-linux-gnu, so

Tested-by: Marcin Wojtas <mw@semihalf.com>