Re: [edk2-devel] [PATCH v4 01/10] BaseTools: add BASETOOLS define

["Ard Biesheuvel" <ardb@kernel.org>]

On Tue, 23 May 2023 at 10:50, Gerd Hoffmann <kraxel@redhat.com> wrote:
>
>   Hi,
>
> > > Works (test patch below for reference).
> >
> > Excellent, thanks for confirming.
> >
> > So I think we should add this for all Clang configurations that enable
> > PIE codegen. We don't support GCC < 5 anyway so this gives us uniform
> > behavior for all ELF based toolchains used for x86.
>
> Which seems to be only X64, so the patch below should be about right
> (doing s/-fpie/-fpie -fdirect-access-external-data/)?
>
> take care,
>   Gerd
>
> From 964965d9da66235e3a29d3735ebdf6c9544b86c3 Mon Sep 17 00:00:00 2001
> From: Gerd Hoffmann <kraxel@redhat.com>
> Date: Mon, 22 May 2023 16:35:54 +0200
> Subject: [PATCH 1/1] BaseTools: add -fdirect-access-external-data to clang pie
>  builds
>
> Tell clang to not use external (via got) references for data access.
>
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

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

> ---
>  BaseTools/Conf/tools_def.template | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/BaseTools/Conf/tools_def.template b/BaseTools/Conf/tools_def.template
> index 503a6687c1f0..92421e3d0118 100755
> --- a/BaseTools/Conf/tools_def.template
> +++ b/BaseTools/Conf/tools_def.template
> @@ -1921,15 +1921,15 @@ NOOPT_CLANGDWARF_IA32_DLINK2_FLAGS     = DEF(CLANGDWARF_IA32_DLINK2_FLAGS) -O0 -
>  *_CLANGDWARF_X64_ASLPP_FLAGS          = DEF(GCC_ASLPP_FLAGS) DEF(CLANGDWARF_X64_TARGET)
>  *_CLANGDWARF_X64_VFRPP_FLAGS          = DEF(GCC_VFRPP_FLAGS) DEF(CLANGDWARF_X64_TARGET)
>
> -DEBUG_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANGDWARF_X64_TARGET) -g
> +DEBUG_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -fdirect-access-external-data -Oz -flto DEF(CLANGDWARF_X64_TARGET) -g
>  DEBUG_CLANGDWARF_X64_DLINK_FLAGS      = DEF(CLANGDWARF_IA32_X64_DLINK_FLAGS) -flto -Wl,-O3 -Wl,-melf_x86_64 -Wl,--oformat,elf64-x86-64 -Wl,-pie -mcmodel=small -Wl,--apply-dynamic-relocs
>  DEBUG_CLANGDWARF_X64_DLINK2_FLAGS     = DEF(CLANGDWARF_X64_DLINK2_FLAGS) -O3 -fuse-ld=lld
>
> -RELEASE_CLANGDWARF_X64_CC_FLAGS       = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -Oz -flto DEF(CLANGDWARF_X64_TARGET)
> +RELEASE_CLANGDWARF_X64_CC_FLAGS       = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -fdirect-access-external-data -Oz -flto DEF(CLANGDWARF_X64_TARGET)
>  RELEASE_CLANGDWARF_X64_DLINK_FLAGS    = DEF(CLANGDWARF_IA32_X64_DLINK_FLAGS) -flto -Wl,-O3 -Wl,-melf_x86_64 -Wl,--oformat,elf64-x86-64 -Wl,-pie -mcmodel=small -Wl,--apply-dynamic-relocs
>  RELEASE_CLANGDWARF_X64_DLINK2_FLAGS   = DEF(CLANGDWARF_X64_DLINK2_FLAGS) -O3 -fuse-ld=lld
>
> -NOOPT_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -O0 DEF(CLANGDWARF_X64_TARGET) -g
> +NOOPT_CLANGDWARF_X64_CC_FLAGS         = DEF(CLANGDWARF_ALL_CC_FLAGS) -m64 "-DEFIAPI=__attribute__((ms_abi))" -mno-red-zone -mcmodel=small -fpie -fdirect-access-external-data -O0 DEF(CLANGDWARF_X64_TARGET) -g
>  NOOPT_CLANGDWARF_X64_DLINK_FLAGS      = DEF(CLANGDWARF_IA32_X64_DLINK_FLAGS) -Wl,-O0 -Wl,-melf_x86_64 -Wl,--oformat,elf64-x86-64 -Wl,-pie -mcmodel=small -Wl,--apply-dynamic-relocs
>  NOOPT_CLANGDWARF_X64_DLINK2_FLAGS     = DEF(CLANGDWARF_X64_DLINK2_FLAGS) -O0 -fuse-ld=lld
>
> --
> 2.40.1
>