arm64/build: Remove .eh_frame* sections due to unwind tables (6e0a66d1) · Commits · 戴 / test

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> Signed-off-by:

Kees Cook <keescook@chromium.org> Signed-off-by:

Ingo Molnar <mingo@kernel.org> Acked-by:

Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200821194310.3089815-11-keescook@chromium.org

arch/arm64/Makefile

+4 −1

Original line number	Diff line number	Diff line
		@@ -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

arch/arm64/kernel/vmlinux.lds.S

+0 −1

Original line number	Diff line number	Diff line
		@@ -94,7 +94,6 @@ SECTIONS
		(.discard.)
		*(.interp .dynamic)
		*(.dynsym .dynstr .hash .gnu.hash)
		*(.eh_frame)
		}

		. = KIMAGE_VADDR + TEXT_OFFSET;

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