Linux-EFI Archive on lore.kernel.org
 help / color / Atom feed
From: Ard Biesheuvel <ardb@kernel.org>
To: Masahiro Yamada <masahiroy@kernel.org>
Cc: linux-kbuild@vger.kernel.org,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	X86 ML <x86@kernel.org>, linux-efi <linux-efi@vger.kernel.org>,
	Kees Cook <keescook@chromium.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/2] kbuild: remove cc-option test of -ffreestanding
Date: Sat, 27 Jun 2020 09:39:03 +0200
Message-ID: <CAMj1kXGsJsU-zbsuWi4O46XqE71DRdKOX1MeC5ndnE+j9Nw7Cw@mail.gmail.com> (raw)
In-Reply-To: <20200626185913.92890-2-masahiroy@kernel.org>

On Fri, 26 Jun 2020 at 21:00, Masahiro Yamada <masahiroy@kernel.org> wrote:
>
> Some Makefiles already pass -ffreestanding unconditionally.
> For example, arch/arm64/lib/Makefile, arch/x86/purgatory/Makefile.
> No problem report so far about hard-coding this option. So, we can
> assume all supported compilers know -ffreestanding.
>
> I confirmed GCC 4.8 and Clang manuals document this option.
>
> Get rid of cc-option from -ffreestanding.
>
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

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

> ---
>
>  arch/s390/Makefile                    | 2 +-
>  arch/x86/Makefile                     | 2 +-
>  arch/x86/boot/compressed/Makefile     | 2 +-
>  drivers/firmware/efi/libstub/Makefile | 2 +-
>  4 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/s390/Makefile b/arch/s390/Makefile
> index 8dfa2cf1f05c..ba94b03c8b2f 100644
> --- a/arch/s390/Makefile
> +++ b/arch/s390/Makefile
> @@ -27,7 +27,7 @@ KBUILD_CFLAGS_DECOMPRESSOR := $(CLANG_FLAGS) -m64 -O2
>  KBUILD_CFLAGS_DECOMPRESSOR += -DDISABLE_BRANCH_PROFILING -D__NO_FORTIFY
>  KBUILD_CFLAGS_DECOMPRESSOR += -fno-delete-null-pointer-checks -msoft-float
>  KBUILD_CFLAGS_DECOMPRESSOR += -fno-asynchronous-unwind-tables
> -KBUILD_CFLAGS_DECOMPRESSOR += $(call cc-option,-ffreestanding)
> +KBUILD_CFLAGS_DECOMPRESSOR += -ffreestanding
>  KBUILD_CFLAGS_DECOMPRESSOR += $(call cc-disable-warning, address-of-packed-member)
>  KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO),-g)
>  KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_DEBUG_INFO_DWARF4), $(call cc-option, -gdwarf-4,))
> diff --git a/arch/x86/Makefile b/arch/x86/Makefile
> index 89c3cdfba753..edc68538a04e 100644
> --- a/arch/x86/Makefile
> +++ b/arch/x86/Makefile
> @@ -36,7 +36,7 @@ REALMODE_CFLAGS       := $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING \
>                    -fno-strict-aliasing -fomit-frame-pointer -fno-pic \
>                    -mno-mmx -mno-sse
>
> -REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -ffreestanding)
> +REALMODE_CFLAGS += -ffreestanding
>  REALMODE_CFLAGS += -fno-stack-protector
>  REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member)
>  REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4))
> diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
> index c88a31569a5e..b7beabecef8a 100644
> --- a/arch/x86/boot/compressed/Makefile
> +++ b/arch/x86/boot/compressed/Makefile
> @@ -35,7 +35,7 @@ cflags-$(CONFIG_X86_32) := -march=i386
>  cflags-$(CONFIG_X86_64) := -mcmodel=small
>  KBUILD_CFLAGS += $(cflags-y)
>  KBUILD_CFLAGS += -mno-mmx -mno-sse
> -KBUILD_CFLAGS += $(call cc-option,-ffreestanding)
> +KBUILD_CFLAGS += -ffreestanding
>  KBUILD_CFLAGS += -fno-stack-protector
>  KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
>  KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
> diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
> index f8418763cd79..296b18fbd7a2 100644
> --- a/drivers/firmware/efi/libstub/Makefile
> +++ b/drivers/firmware/efi/libstub/Makefile
> @@ -28,7 +28,7 @@ cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt
>  KBUILD_CFLAGS                  := $(cflags-y) -Os -DDISABLE_BRANCH_PROFILING \
>                                    -include $(srctree)/drivers/firmware/efi/libstub/hidden.h \
>                                    -D__NO_FORTIFY \
> -                                  $(call cc-option,-ffreestanding) \
> +                                  -ffreestanding \
>                                    -fno-stack-protector \
>                                    $(call cc-option,-fno-addrsig) \
>                                    -D__DISABLE_EXPORTS
> --
> 2.25.1
>

  parent reply index

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-26 18:59 [PATCH 1/2] kbuild: remove cc-option test of -fno-stack-protector Masahiro Yamada
2020-06-26 18:59 ` [PATCH 2/2] kbuild: remove cc-option test of -ffreestanding Masahiro Yamada
2020-06-26 19:58   ` Nick Desaulniers
2020-06-26 20:22   ` Kees Cook
2020-06-27  7:39   ` Ard Biesheuvel [this message]
2020-06-26 19:09 ` [PATCH 1/2] kbuild: remove cc-option test of -fno-stack-protector Nick Desaulniers
2020-06-26 20:00   ` Masahiro Yamada
2020-06-26 20:13   ` Kees Cook
2020-06-26 20:13 ` Nick Desaulniers
2020-06-26 20:21   ` Kees Cook
2020-06-26 20:25     ` Nick Desaulniers
2020-06-26 20:37       ` Kees Cook
2020-06-27 11:58   ` Masahiro Yamada
2020-06-29 18:26     ` Nick Desaulniers
2020-06-29 22:39       ` Nick Desaulniers
2020-06-30 18:18         ` Masahiro Yamada
2020-07-01 19:33         ` Masahiro Yamada
2020-06-26 20:18 ` Kees Cook
2020-06-27  7:39 ` Ard Biesheuvel
2020-07-01  6:01 ` Marco Elver

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAMj1kXGsJsU-zbsuWi4O46XqE71DRdKOX1MeC5ndnE+j9Nw7Cw@mail.gmail.com \
    --to=ardb@kernel.org \
    --cc=clang-built-linux@googlegroups.com \
    --cc=keescook@chromium.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=masahiroy@kernel.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-EFI Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-efi/0 linux-efi/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-efi linux-efi/ https://lore.kernel.org/linux-efi \
		linux-efi@vger.kernel.org
	public-inbox-index linux-efi

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-efi


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git