[PATCH v6 18/29] arm/build: Assert for unwanted sections
From: Kees Cook <hidden>
Date: 2020-08-21 19:45:54
Also in:
linux-arch, linux-arm-kernel, lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
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 <redacted> --- 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
--
2.25.1