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

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 13 June 2018 at 12:16, Gao, Liming <liming.gao@intel.com> wrote:
> Ard:
>   This patch causes GCC49 IA32 build failure with GCC compiler 4.9.2 in link phase. " gcc: error: unrecognized command line option -no-pie"
>   Do you know any option to disable this error?
>

Sorry about that.

I guess the assumption that this was safe for GCC49 was incorrect after all.

Shall I send a patch to move back to setting it for GCC5 only?

>>-----Original Message-----
>>From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org]
>>Sent: Tuesday, June 12, 2018 2:19 PM
>>To: Gao, Liming <liming.gao@intel.com>
>>Cc: edk2-devel@lists.01.org; lersek@redhat.com; Zhu, Yonghong
>><yonghong.zhu@intel.com>
>>Subject: Re: [PATCH v2] BaseTools/tools_def IA32: disable PIE code
>>generation explicitly
>>
>>On 12 June 2018 at 03:40, Gao, Liming <liming.gao@intel.com> wrote:
>>> Reviewed-by: Liming Gao <liming.gao@intel.com>
>>>
>>
>>Thanks
>>
>>Pushed as c25d3905523a
>>
>>>> -----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
>>>