@@ -16,6 +16,10 @@ LDFLAGS_vmlinux += --be8
KBUILD_LDFLAGS_MODULE += --be8
endif
+# We never want expected sections to be placed heuristically by the
+# linker. All sections should be explicitly named in the linker script.
+LDFLAGS_vmlinux += --orphan-handling=warn
+
ifeq ($(CONFIG_ARM_MODULE_PLTS),y)
KBUILD_LDS_MODULE += $(srctree)/arch/arm/kernel/module.lds
endif
similarity index 92%
rename from arch/arm/kernel/vmlinux.lds.h
rename to arch/arm/include/asm/vmlinux.lds.h
@@ -1,4 +1,5 @@
/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm-generic/vmlinux.lds.h>
#ifdef CONFIG_HOTPLUG_CPU
#define ARM_CPU_DISCARD(x)
@@ -37,6 +38,13 @@
*(.idmap.text) \
__idmap_text_end = .; \
+#define ARM_COMMON_DISCARD \
+ *(.ARM.attributes) \
+ *(.iplt) *(.rel.iplt) *(.igot.plt) \
+ *(.modinfo) \
+ *(.discard) \
+ *(.discard.*)
+
#define ARM_DISCARD \
*(.ARM.exidx.exit.text) \
*(.ARM.extab.exit.text) \
@@ -49,8 +57,14 @@
EXIT_CALL \
ARM_MMU_DISCARD(*(.text.fixup)) \
ARM_MMU_DISCARD(*(__ex_table)) \
- *(.discard) \
- *(.discard.*)
+ ARM_COMMON_DISCARD
+
+#define ARM_STUBS_TEXT \
+ *(.gnu.warning) \
+ *(.glue_7t) \
+ *(.glue_7) \
+ *(.vfp11_veneer) \
+ *(.v4_bx)
#define ARM_TEXT \
IDMAP_TEXT \
@@ -64,9 +78,7 @@
CPUIDLE_TEXT \
LOCK_TEXT \
KPROBES_TEXT \
- *(.gnu.warning) \
- *(.glue_7) \
- *(.glue_7t) \
+ ARM_STUBS_TEXT \
. = ALIGN(4); \
*(.got) /* Global offset table */ \
ARM_CPU_KEEP(PROC_INFO)
@@ -9,15 +9,13 @@
#include <linux/sizes.h>
-#include <asm-generic/vmlinux.lds.h>
+#include <asm/vmlinux.lds.h>
#include <asm/cache.h>
#include <asm/thread_info.h>
#include <asm/memory.h>
#include <asm/mpu.h>
#include <asm/page.h>
-#include "vmlinux.lds.h"
-
OUTPUT_ARCH(arm)
ENTRY(stext)
@@ -152,6 +150,7 @@ SECTIONS
_end = .;
STABS_DEBUG
+ DWARF_DEBUG
}
/*
@@ -9,15 +9,13 @@
#else
#include <linux/pgtable.h>
-#include <asm-generic/vmlinux.lds.h>
+#include <asm/vmlinux.lds.h>
#include <asm/cache.h>
#include <asm/thread_info.h>
#include <asm/memory.h>
#include <asm/mpu.h>
#include <asm/page.h>
-#include "vmlinux.lds.h"
-
OUTPUT_ARCH(arm)
ENTRY(stext)
@@ -151,6 +149,7 @@ SECTIONS
_end = .;
STABS_DEBUG
+ DWARF_DEBUG
}
#ifdef CONFIG_STRICT_KERNEL_RWX
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' Refactor linker script include file for use in standard and XIP linker scripts, as well as in the coming boot linker script changes. Add debug sections explicitly. Create ARM_COMMON_DISCARD macro with unneeded sections .ARM.attributes, .iplt, .rel.iplt, .igot.plt, and .modinfo. Create ARM_STUBS_TEXT macro with missed text stub sections .vfp11_veneer, and .v4_bx. Finally enable orphan section warning. Signed-off-by: Kees Cook <keescook@chromium.org> --- arch/arm/Makefile | 4 ++++ .../arm/{kernel => include/asm}/vmlinux.lds.h | 22 ++++++++++++++----- arch/arm/kernel/vmlinux-xip.lds.S | 5 ++--- arch/arm/kernel/vmlinux.lds.S | 5 ++--- 4 files changed, 25 insertions(+), 11 deletions(-) rename arch/arm/{kernel => include/asm}/vmlinux.lds.h (92%)