[PATCH v6 10/29] arm64/build: Remove .eh_frame* sections due to unwind tables
From: Kees Cook <hidden>
Date: 2020-08-21 19:46:16
Also in:
linux-arm-kernel, linux-efi, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Avoid .eh_frame* section generation by making sure both CFLAGS and AFLAGS contain -fno-asychronous-unwind-tables and -fno-unwind-tables. With all sources of .eh_frame now removed from the build, drop this DISCARD so we can be alerted in the future if it returns unexpectedly once orphan section warnings have been enabled. Suggested-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Kees Cook <redacted> --- arch/arm64/Makefile | 5 ++++- arch/arm64/kernel/vmlinux.lds.S | 1 - 2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 55bc8546d9c7..6de7f551b821 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile@@ -47,13 +47,16 @@ endif KBUILD_CFLAGS += -mgeneral-regs-only \ $(compat_vdso) $(cc_has_k_constraint) -KBUILD_CFLAGS += -fno-asynchronous-unwind-tables KBUILD_CFLAGS += $(call cc-disable-warning, psabi) KBUILD_AFLAGS += $(compat_vdso) KBUILD_CFLAGS += $(call cc-option,-mabi=lp64) KBUILD_AFLAGS += $(call cc-option,-mabi=lp64) +# Avoid generating .eh_frame* sections. +KBUILD_CFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables +KBUILD_AFLAGS += -fno-asynchronous-unwind-tables -fno-unwind-tables + ifeq ($(CONFIG_STACKPROTECTOR_PER_TASK),y) prepare: stack_protector_prepare stack_protector_prepare: prepare0
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 13fc2ec46aae..c2b8426bf4bd 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S@@ -94,7 +94,6 @@ SECTIONS *(.discard.*) *(.interp .dynamic) *(.dynsym .dynstr .hash .gnu.hash) - *(.eh_frame) } . = KIMAGE_VADDR + TEXT_OFFSET;
--
2.25.1