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@xxxxxxxxxxxx>
---
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
