Re: [PATCH v2] BaseTools/tools_def IA32: disable PIE code generation explicitly

["Gao, Liming" <liming.gao@intel.com>]

Reviewed-by: Liming Gao <liming.gao@intel.com>

> -----Original Message-----
> From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org]
> Sent: Tuesday, June 12, 2018 12:29 AM
> To: edk2-devel@lists.01.org
> Cc: lersek@redhat.com; Gao, Liming <liming.gao@intel.com>; Zhu, Yonghong <yonghong.zhu@intel.com>; Ard Biesheuvel
> <ard.biesheuvel@linaro.org>
> Subject: [PATCH v2] BaseTools/tools_def IA32: disable PIE code generation explicitly
> 
> As a security measure, some distros now build their GCC toolchains with
> PIE code generation enabled by default, because it is a prerequisite
> for ASLR to be enabled when running the executable.
> 
> This typically results in slightly larger code, but it also generates
> ELF relocations that our tooling cannot deal with, so let's disable it
> explicitly when using GCC49 or later for IA32. (Note that this does not
> apply to X64: it uses PIE code deliberately in some cases, and our
> tooling does deal with the resuling relocations)
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Acked-by: Laszlo Ersek <lersek@redhat.com>
> ---
>  BaseTools/Conf/tools_def.template | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
> index 7e9c915755ed..733c6ec71709 100755
> --- a/BaseTools/Conf/tools_def.template
> +++ b/BaseTools/Conf/tools_def.template
> @@ -4648,7 +4648,7 @@ DEFINE GCC48_AARCH64_DLINK2_FLAGS    = DEF(GCC47_AARCH64_DLINK2_FLAGS)
>  DEFINE GCC48_ARM_ASLDLINK_FLAGS      = DEF(GCC47_ARM_ASLDLINK_FLAGS)
>  DEFINE GCC48_AARCH64_ASLDLINK_FLAGS  = DEF(GCC47_AARCH64_ASLDLINK_FLAGS)
> 
> -DEFINE GCC49_IA32_CC_FLAGS           = DEF(GCC48_IA32_CC_FLAGS)
> +DEFINE GCC49_IA32_CC_FLAGS           = DEF(GCC48_IA32_CC_FLAGS) -fno-pic -fno-pie
>  DEFINE GCC49_X64_CC_FLAGS            = DEF(GCC48_X64_CC_FLAGS)
>  DEFINE GCC49_IA32_X64_DLINK_COMMON   = -nostdlib -Wl,-n,-q,--gc-sections -z common-page-size=0x40
>  DEFINE GCC49_IA32_X64_ASLDLINK_FLAGS = DEF(GCC49_IA32_X64_DLINK_COMMON) -Wl,--entry,ReferenceAcpiTable -u
> ReferenceAcpiTable
> @@ -5357,10 +5357,10 @@ RELEASE_GCC48_AARCH64_CC_FLAGS   = DEF(GCC48_AARCH64_CC_FLAGS) -Wno-unused-but-s
>  *_GCC49_IA32_RC_PATH              = DEF(GCC49_IA32_PREFIX)objcopy
> 
>  *_GCC49_IA32_ASLCC_FLAGS          = DEF(GCC_ASLCC_FLAGS) -m32
> -*_GCC49_IA32_ASLDLINK_FLAGS       = DEF(GCC49_IA32_X64_ASLDLINK_FLAGS) -Wl,-m,elf_i386
> +*_GCC49_IA32_ASLDLINK_FLAGS       = DEF(GCC49_IA32_X64_ASLDLINK_FLAGS) -Wl,-m,elf_i386 -no-pie
>  *_GCC49_IA32_ASM_FLAGS            = DEF(GCC49_ASM_FLAGS) -m32 -march=i386
>  *_GCC49_IA32_DLINK_FLAGS          = DEF(GCC49_IA32_X64_DLINK_FLAGS) -Wl,-m,elf_i386,--oformat=elf32-i386
> -*_GCC49_IA32_DLINK2_FLAGS         = DEF(GCC49_IA32_DLINK2_FLAGS)
> +*_GCC49_IA32_DLINK2_FLAGS         = DEF(GCC49_IA32_DLINK2_FLAGS) -no-pie
>  *_GCC49_IA32_RC_FLAGS             = DEF(GCC_IA32_RC_FLAGS)
>  *_GCC49_IA32_OBJCOPY_FLAGS        =
>  *_GCC49_IA32_NASM_FLAGS           = -f elf32
> @@ -5502,9 +5502,9 @@ RELEASE_GCC49_AARCH64_DLINK_FLAGS  = DEF(GCC49_AARCH64_DLINK_FLAGS)
>  *_GCC5_IA32_RC_PATH              = DEF(GCC5_IA32_PREFIX)objcopy
> 
>  *_GCC5_IA32_ASLCC_FLAGS          = DEF(GCC_ASLCC_FLAGS) -m32 -fno-lto
> -*_GCC5_IA32_ASLDLINK_FLAGS       = DEF(GCC5_IA32_X64_ASLDLINK_FLAGS) -Wl,-m,elf_i386
> +*_GCC5_IA32_ASLDLINK_FLAGS       = DEF(GCC5_IA32_X64_ASLDLINK_FLAGS) -Wl,-m,elf_i386 -no-pie
>  *_GCC5_IA32_ASM_FLAGS            = DEF(GCC5_ASM_FLAGS) -m32 -march=i386
> -*_GCC5_IA32_DLINK2_FLAGS         = DEF(GCC5_IA32_DLINK2_FLAGS)
> +*_GCC5_IA32_DLINK2_FLAGS         = DEF(GCC5_IA32_DLINK2_FLAGS) -no-pie
>  *_GCC5_IA32_RC_FLAGS             = DEF(GCC_IA32_RC_FLAGS)
>  *_GCC5_IA32_OBJCOPY_FLAGS        =
>  *_GCC5_IA32_NASM_FLAGS           = -f elf32
> --
> 2.17.1