[v6,18/29] arm/build: Assert for unwanted sections

Message ID	20200821194310.3089815-19-keescook@chromium.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=QQOt=B7=lists.infradead.org=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@kernel.org> DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A3FE920738 From: Kees Cook <keescook@chromium.org> To: Ingo Molnar <mingo@kernel.org> Subject: [PATCH v6 18/29] arm/build: Assert for unwanted sections Date: Fri, 21 Aug 2020 12:42:59 -0700 Message-Id: <20200821194310.3089815-19-keescook@chromium.org> In-Reply-To: <20200821194310.3089815-1-keescook@chromium.org> References: <20200821194310.3089815-1-keescook@chromium.org> MIME-Version: 1.0 summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [2607:f8b0:4864:20:0:0:0:641 listed in] [list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender Precedence: list Cc: Mark Rutland <mark.rutland@arm.com>, linux-arch@vger.kernel.org, linux-efi@vger.kernel.org, Kees Cook <keescook@chromium.org>, Arnd Bergmann <arnd@arndb.de>, Catalin Marinas <catalin.marinas@arm.com>, Masahiro Yamada <masahiroy@kernel.org>, x86@kernel.org, Nick Desaulniers <ndesaulniers@google.com>, Russell King <linux@armlinux.org.uk>, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Arvind Sankar <nivedita@alum.mit.edu>, Ingo Molnar <mingo@redhat.com>, James Morse <james.morse@arm.com>, Nathan Chancellor <natechancellor@gmail.com>, Borislav Petkov <bp@suse.de>, Peter Collingbourne <pcc@google.com>, Ard Biesheuvel <ardb@kernel.org>, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org
Series	Warn on orphan section placement \| expand [v6,00/29] Warn on orphan section placement [v6,01/29] vmlinux.lds.h: Create COMMON_DISCARDS [v6,02/29] vmlinux.lds.h: Add .gnu.version* to COMMON_DISCARDS [v6,03/29] vmlinux.lds.h: Avoid KASAN and KCSAN's unwanted sections [v6,04/29] vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG [v6,05/29] vmlinux.lds.h: Add .symtab, .strtab, and .shstrtab to ELF_DETAILS [v6,06/29] vmlinux.lds.h: add PGO and AutoFDO input sections [v6,07/29] efi/libstub: Disable -mbranch-protection [v6,08/29] arm64/mm: Remove needless section quotes [v6,09/29] arm64/kernel: Remove needless Call Frame Information annotations [v6,10/29] arm64/build: Remove .eh_frame* sections due to unwind tables [v6,11/29] arm64/build: Use common DISCARDS in linker script [v6,12/29] arm64/build: Add missing DWARF sections [v6,13/29] arm64/build: Assert for unwanted sections [v6,14/29] arm64/build: Warn on orphan section placement [v6,15/29] arm/build: Refactor linker script headers [v6,16/29] arm/build: Explicitly keep .ARM.attributes sections [v6,17/29] arm/build: Add missing sections [v6,18/29] arm/build: Assert for unwanted sections [v6,19/29] arm/build: Warn on orphan section placement [v6,20/29] arm/boot: Handle all sections explicitly [v6,21/29] arm/boot: Warn on orphan section placement [v6,22/29] x86/asm: Avoid generating unused kprobe sections [v6,23/29] x86/build: Enforce an empty .got.plt section [v6,24/29] x86/build: Assert for unwanted sections [v6,25/29] x86/build: Warn on orphan section placement [v6,26/29] x86/boot/compressed: Reorganize zero-size section asserts [v6,27/29] x86/boot/compressed: Remove, discard, or assert for unwanted sections [v6,28/29] x86/boot/compressed: Add missing debugging sections to output [v6,29/29] x86/boot/compressed: Warn on orphan section placement

Message ID

20200821194310.3089815-19-keescook@chromium.org (mailing list archive)

State

New, archived

Headers

DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A3FE920738
From: Kees Cook <keescook@chromium.org>
To: Ingo Molnar <mingo@kernel.org>
Subject: [PATCH v6 18/29] arm/build: Assert for unwanted sections
Date: Fri, 21 Aug 2020 12:42:59 -0700
Message-Id: <20200821194310.3089815-19-keescook@chromium.org>
In-Reply-To: <20200821194310.3089815-1-keescook@chromium.org>
References: <20200821194310.3089815-1-keescook@chromium.org>
MIME-Version: 1.0
Precedence: list
Cc: Mark Rutland <mark.rutland@arm.com>, linux-arch@vger.kernel.org,
 linux-efi@vger.kernel.org, Kees Cook <keescook@chromium.org>,
 Arnd Bergmann <arnd@arndb.de>, Catalin Marinas <catalin.marinas@arm.com>,
 Masahiro Yamada <masahiroy@kernel.org>, x86@kernel.org,
 Nick Desaulniers <ndesaulniers@google.com>,
 Russell King <linux@armlinux.org.uk>, linux-kernel@vger.kernel.org,
 clang-built-linux@googlegroups.com, Arvind Sankar <nivedita@alum.mit.edu>,
 Ingo Molnar <mingo@redhat.com>, James Morse <james.morse@arm.com>,
 Nathan Chancellor <natechancellor@gmail.com>, Borislav Petkov <bp@suse.de>,
 Peter Collingbourne <pcc@google.com>, Ard Biesheuvel <ardb@kernel.org>,
 linux-arm-kernel@lists.infradead.org
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 linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

Series

Warn on orphan section placement | expand

Commit Message

Kees Cook Aug. 21, 2020, 7:42 p.m. UTC

In preparation for warning on orphan sections, enforce
expected-to-be-zero-sized sections (since discarding them might hide
problems with them suddenly gaining unexpected entries).

Signed-off-by: Kees Cook <keescook@chromium.org>
---
 arch/arm/include/asm/vmlinux.lds.h | 11 +++++++++++
 arch/arm/kernel/vmlinux-xip.lds.S  |  2 ++
 arch/arm/kernel/vmlinux.lds.S      |  2 ++
 3 files changed, 15 insertions(+)

diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h
index 6624dd97475c..4a91428c324d 100644
--- a/arch/arm/include/asm/vmlinux.lds.h
+++ b/arch/arm/include/asm/vmlinux.lds.h
@@ -52,6 +52,17 @@ 
 		ARM_MMU_DISCARD(*(__ex_table))				\
 		COMMON_DISCARDS
 
+/*
+ * Sections that should stay zero sized, which is safer to explicitly
+ * check instead of blindly discarding.
+ */
+#define ARM_ASSERTS							\
+	.plt : {							\
+		*(.iplt) *(.rel.iplt) *(.iplt) *(.igot.plt)		\
+	}								\
+	ASSERT(SIZEOF(.plt) == 0,					\
+	       "Unexpected run-time procedure linkages detected!")
+
 #define ARM_DETAILS							\
 		ELF_DETAILS						\
 		.ARM.attributes 0 : { *(.ARM.attributes) }
diff --git a/arch/arm/kernel/vmlinux-xip.lds.S b/arch/arm/kernel/vmlinux-xip.lds.S
index 11ffa79751da..50136828f5b5 100644
--- a/arch/arm/kernel/vmlinux-xip.lds.S
+++ b/arch/arm/kernel/vmlinux-xip.lds.S
@@ -152,6 +152,8 @@  SECTIONS
 	STABS_DEBUG
 	DWARF_DEBUG
 	ARM_DETAILS
+
+	ARM_ASSERTS
 }
 
 /*
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index dc672fe35de3..5f4922e858d0 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -151,6 +151,8 @@  SECTIONS
 	STABS_DEBUG
 	DWARF_DEBUG
 	ARM_DETAILS
+
+	ARM_ASSERTS
 }
 
 #ifdef CONFIG_STRICT_KERNEL_RWX

[v6,18/29] arm/build: Assert for unwanted sections

Commit Message

Patch