From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [PATCH v4 14/17] arm/build: Warn on orphan section placement Date: Sun, 28 Jun 2020 23:18:37 -0700 Message-ID: <20200629061840.4065483-15-keescook@chromium.org> References: <20200629061840.4065483-1-keescook@chromium.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20200629061840.4065483-1-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org To: Will Deacon Cc: Kees Cook , Catalin Marinas , Mark Rutland , Ard Biesheuvel , Peter Collingbourne , James Morse , Borislav Petkov , Thomas Gleixner , Ingo Molnar , Russell King , Masahiro Yamada , Arvind Sankar , Nick Desaulniers , Nathan Chancellor , Arnd Bergmann , x86@kernel.org, clang-built-linux@googlegroups.com, linux-arch@vger.kernel.org, linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: linux-arch.vger.kernel.org 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 --- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731444AbgF2TNf (ORCPT ); Mon, 29 Jun 2020 15:13:35 -0400 Received: from mail-pj1-x1041.google.com (mail-pj1-x1041.google.com [IPv6:2607:f8b0:4864:20::1041]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D90FC08EB14 for ; Sun, 28 Jun 2020 23:18:55 -0700 (PDT) Received: by mail-pj1-x1041.google.com with SMTP id gc15so574488pjb.0 for ; Sun, 28 Jun 2020 23:18:55 -0700 (PDT) From: Kees Cook Subject: [PATCH v4 14/17] arm/build: Warn on orphan section placement Date: Sun, 28 Jun 2020 23:18:37 -0700 Message-ID: <20200629061840.4065483-15-keescook@chromium.org> In-Reply-To: <20200629061840.4065483-1-keescook@chromium.org> References: <20200629061840.4065483-1-keescook@chromium.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: Will Deacon Cc: Kees Cook , Catalin Marinas , Mark Rutland , Ard Biesheuvel , Peter Collingbourne , James Morse , Borislav Petkov , Thomas Gleixner , Ingo Molnar , Russell King , Masahiro Yamada , Arvind Sankar , Nick Desaulniers , Nathan Chancellor , Arnd Bergmann , x86@kernel.org, clang-built-linux@googlegroups.com, linux-arch@vger.kernel.org, linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Message-ID: <20200629061837.xFDMOZItbT7KZiabP0nQiVwC1PzFm9TUEKH6FyjFSUc@z> 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 --- 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