From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: [PATCH v3 7/9] arm/boot: Warn on orphan section placement Date: Tue, 23 Jun 2020 18:49:38 -0700 Message-ID: <20200624014940.1204448-8-keescook@chromium.org> References: <20200624014940.1204448-1-keescook@chromium.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46746 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388575AbgFXBty (ORCPT ); Tue, 23 Jun 2020 21:49:54 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A62DC06179B for ; Tue, 23 Jun 2020 18:49:54 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id e9so561785pgo.9 for ; Tue, 23 Jun 2020 18:49:54 -0700 (PDT) In-Reply-To: <20200624014940.1204448-1-keescook@chromium.org> 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 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. Use common macros for debug sections, discards, and text stubs. Add discards for unwanted .note, and .rel sections. Finally, enable orphan section warning. Signed-off-by: Kees Cook --- arch/arm/boot/compressed/Makefile | 2 ++ arch/arm/boot/compressed/vmlinux.lds.S | 17 +++++++---------- 2 files changed, 9 insertions(+), 10 deletions(-) diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index 00602a6fba04..b8a97d81662d 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -128,6 +128,8 @@ endif LDFLAGS_vmlinux += --no-undefined # Delete all temporary local symbols LDFLAGS_vmlinux += -X +# Report orphan sections +LDFLAGS_vmlinux += --orphan-handling=warn # Next argument is a linker script LDFLAGS_vmlinux += -T diff --git a/arch/arm/boot/compressed/vmlinux.lds.S b/arch/arm/boot/compressed/vmlinux.lds.S index 09ac33f52814..c2a8509f876f 100644 --- a/arch/arm/boot/compressed/vmlinux.lds.S +++ b/arch/arm/boot/compressed/vmlinux.lds.S @@ -2,6 +2,7 @@ /* * Copyright (C) 2000 Russell King */ +#include #ifdef CONFIG_CPU_ENDIAN_BE8 #define ZIMAGE_MAGIC(x) ( (((x) >> 24) & 0x000000ff) | \ @@ -17,8 +18,11 @@ ENTRY(_start) SECTIONS { /DISCARD/ : { + ARM_COMMON_DISCARD *(.ARM.exidx*) *(.ARM.extab*) + *(.note.*) + *(.rel.*) /* * Discard any r/w data - this produces a link error if we have any, * which is required for PIC decompression. Local data generates @@ -36,9 +40,7 @@ SECTIONS *(.start) *(.text) *(.text.*) - *(.gnu.warning) - *(.glue_7t) - *(.glue_7) + ARM_STUBS_TEXT } .table : ALIGN(4) { _table_start = .; @@ -128,12 +130,7 @@ SECTIONS PROVIDE(__pecoff_data_size = ALIGN(512) - ADDR(.data)); PROVIDE(__pecoff_end = ALIGN(512)); - .stab 0 : { *(.stab) } - .stabstr 0 : { *(.stabstr) } - .stab.excl 0 : { *(.stab.excl) } - .stab.exclstr 0 : { *(.stab.exclstr) } - .stab.index 0 : { *(.stab.index) } - .stab.indexstr 0 : { *(.stab.indexstr) } - .comment 0 : { *(.comment) } + STABS_DEBUG + DWARF_DEBUG } ASSERT(_edata_real == _edata, "error: zImage file size is incorrect"); -- 2.25.1