Linux-EFI Archive on lore.kernel.org
 help / color / Atom feed
From: Nick Desaulniers <ndesaulniers@google.com>
To: Kees Cook <keescook@chromium.org>
Cc: Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Ard Biesheuvel <ardb@kernel.org>,
	Peter Collingbourne <pcc@google.com>,
	James Morse <james.morse@arm.com>, Borislav Petkov <bp@suse.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Russell King <linux@armlinux.org.uk>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Arvind Sankar <nivedita@alum.mit.edu>,
	Nathan Chancellor <natechancellor@gmail.com>,
	Arnd Bergmann <arnd@arndb.de>,
	"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
	<x86@kernel.org>,
	clang-built-linux <clang-built-linux@googlegroups.com>,
	linux-arch <linux-arch@vger.kernel.org>,
	linux-efi <linux-efi@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 14/17] arm/build: Warn on orphan section placement
Date: Mon, 29 Jun 2020 12:47:03 -0700
Message-ID: <CAKwvOdnErUWrJUaw9gm3ZSOpD2JepZKod3REBctzBr4QuHLiAA@mail.gmail.com> (raw)
In-Reply-To: <20200629061840.4065483-15-keescook@chromium.org>

On Sun, Jun 28, 2020 at 11:18 PM Kees Cook <keescook@chromium.org> wrote:
>
> We don't want to depend on the linker's orphan section placement
> heuristics as these can vary between linkers, and may change between
> versions. All sections need to be explicitly named in the linker
> script.
>
> Specifically, this would have made a recently fixed bug very obvious:
>
> ld: warning: orphan section `.fixup' from `arch/arm/lib/copy_from_user.o' being placed in section `.fixup'
>
> Discard unneeded sections .iplt, .rel.iplt, .igot.plt, and .modinfo.
>
> Add missing text stub sections .vfp11_veneer and .v4_bx.
>
> Add debug sections explicitly.
>
> Finally enable orphan section warning.
>
> Signed-off-by: Kees Cook <keescook@chromium.org>

Thanks for following up on the previous suggestion regarding .glu_7 /
.glu_7t ordering. LGTM
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
>  arch/arm/include/asm/vmlinux.lds.h | 6 +++++-
>  arch/arm/kernel/vmlinux-xip.lds.S  | 1 +
>  arch/arm/kernel/vmlinux.lds.S      | 1 +
>  3 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h
> index c66b16cd8837..d44fae722e7a 100644
> --- a/arch/arm/include/asm/vmlinux.lds.h
> +++ b/arch/arm/include/asm/vmlinux.lds.h
> @@ -39,6 +39,8 @@
>                 __idmap_text_end = .;                                   \
>
>  #define ARM_COMMON_DISCARD                                             \
> +               *(.iplt) *(.rel.iplt) *(.igot.plt)                      \
> +               *(.modinfo)                                             \
>                 *(.discard)                                             \
>                 *(.discard.*)
>
> @@ -63,7 +65,9 @@
>  #define ARM_STUBS_TEXT                                                 \
>                 *(.gnu.warning)                                         \
>                 *(.glue_7)                                              \
> -               *(.glue_7t)
> +               *(.glue_7t)                                             \
> +               *(.vfp11_veneer)                                        \
> +               *(.v4_bx)
>
>  #define ARM_TEXT                                                       \
>                 IDMAP_TEXT                                              \
> diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
> index 57fcbf55f913..11ffa79751da 100644
> --- a/arch/arm/kernel/vmlinux-xip.lds.S
> +++ b/arch/arm/kernel/vmlinux-xip.lds.S
> @@ -150,6 +150,7 @@ SECTIONS
>         _end = .;
>
>         STABS_DEBUG
> +       DWARF_DEBUG
>         ARM_DETAILS
>  }
>
> diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
> index 1d3d3b599635..dc672fe35de3 100644
> --- a/arch/arm/kernel/vmlinux.lds.S
> +++ b/arch/arm/kernel/vmlinux.lds.S
> @@ -149,6 +149,7 @@ SECTIONS
>         _end = .;
>
>         STABS_DEBUG
> +       DWARF_DEBUG
>         ARM_DETAILS
>  }
>
> --
> 2.25.1
>
> --
> You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200629061840.4065483-15-keescook%40chromium.org.



-- 
Thanks,
~Nick Desaulniers

  parent reply index

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-29  6:18 [PATCH v4 00/17] " Kees Cook
2020-06-29  6:18 ` [PATCH v4 01/17] vmlinux.lds.h: Add .gnu.version* to DISCARDS Kees Cook
2020-06-29  6:18 ` [PATCH v4 02/17] vmlinux.lds.h: Avoid KASAN and KCSAN's unwanted sections Kees Cook
2020-06-29  6:18 ` [PATCH v4 03/17] vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG Kees Cook
2020-06-29  6:18 ` [PATCH v4 04/17] vmlinux.lds.h: Add .symtab, .strtab, and .shstrtab to ELF_DETAILS Kees Cook
2020-06-29  6:18 ` [PATCH v4 05/17] ctype: Work around Clang -mbranch-protection=none bug Kees Cook
2020-06-29  8:15   ` Ard Biesheuvel
2020-06-29 14:43     ` Kees Cook
2020-06-29 15:06     ` Kees Cook
2020-06-29 15:08       ` Ard Biesheuvel
2020-06-29 15:16         ` Kees Cook
2020-06-29 18:02       ` Nick Desaulniers
2020-06-29 18:37         ` Kees Cook
2020-06-29  6:18 ` [PATCH v4 06/17] efi/libstub: Disable -mbranch-protection Kees Cook
2020-06-29  6:18 ` [PATCH v4 07/17] arm64/build: Use common DISCARDS in linker script Kees Cook
2020-06-29  6:18 ` [PATCH v4 08/17] arm64/mm: Remove needless section quotes Kees Cook
2020-06-29 19:53   ` Nick Desaulniers
2020-06-29 20:03     ` Joe Perches
2020-06-29 20:29       ` Nick Desaulniers
2020-06-29 20:04     ` Kees Cook
2020-06-29 20:54       ` Arvind Sankar
2020-06-29 21:06         ` Arvind Sankar
2020-06-29  6:18 ` [PATCH v4 09/17] arm64/build: Remove .eh_frame* sections due to unwind tables Kees Cook
2020-06-29  6:18 ` [PATCH v4 10/17] arm64/kernel: Remove needless Call Frame Information annotations Kees Cook
2020-06-29  6:18 ` [PATCH v4 11/17] arm64/build: Warn on orphan section placement Kees Cook
2020-06-29  6:18 ` [PATCH v4 12/17] arm/build: Refactor linker script headers Kees Cook
2020-06-29  6:18 ` [PATCH v4 13/17] arm/build: Explicitly keep .ARM.attributes sections Kees Cook
2020-06-29  6:18 ` [PATCH v4 14/17] arm/build: Warn on orphan section placement Kees Cook
2020-06-29 15:54   ` Arvind Sankar
2020-06-29 18:07     ` Russell King - ARM Linux admin
2020-06-29 18:15       ` Arvind Sankar
2020-06-29 19:03         ` Russell King - ARM Linux admin
2020-06-29 19:47   ` Nick Desaulniers [this message]
2020-06-29  6:18 ` [PATCH v4 15/17] arm/boot: " Kees Cook
2020-06-29  6:18 ` [PATCH v4 16/17] x86/build: " Kees Cook
2020-06-29  6:18 ` [PATCH v4 17/17] x86/boot: " Kees Cook

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=CAKwvOdnErUWrJUaw9gm3ZSOpD2JepZKod3REBctzBr4QuHLiAA@mail.gmail.com \
    --to=ndesaulniers@google.com \
    --cc=ardb@kernel.org \
    --cc=arnd@arndb.de \
    --cc=bp@suse.de \
    --cc=catalin.marinas@arm.com \
    --cc=clang-built-linux@googlegroups.com \
    --cc=james.morse@arm.com \
    --cc=keescook@chromium.org \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=mark.rutland@arm.com \
    --cc=masahiroy@kernel.org \
    --cc=mingo@redhat.com \
    --cc=natechancellor@gmail.com \
    --cc=nivedita@alum.mit.edu \
    --cc=pcc@google.com \
    --cc=tglx@linutronix.de \
    --cc=will@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