Commit 5a17850e authored Sep 01, 2020 by Kees Cook Committed by Ingo Molnar Sep 03, 2020

arm/build: Warn on orphan section placement



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 handled 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'

With all sections handled, enable orphan section warning.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20200902025347.2504702-3-keescook@chromium.org

parent b3e5d80d

arch/arm/Makefile

+4 −0

Original line number	Diff line number	Diff line
		@@ -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 += $(call ld-option, --orphan-handling=warn)

		ifeq ($(CONFIG_ARM_MODULE_PLTS),y)
		KBUILD_LDS_MODULE += $(srctree)/arch/arm/kernel/module.lds
		endif

Admin message