[PATCH v3 08/28] efi/libstub: Drop .discard.addressable from the stub objects
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: 2026-09-21 22:31:41
Also in:
lkml, rust-for-linux
Subsystem:
extensible firmware interface (efi), the rest · Maintainers:
Ard Biesheuvel, Linus Torvalds
On arm64, riscv and loongarch, the EFI stub objects are objcopy'd with --prefix-alloc-sections=.init, which renames every allocatable section. The .discard.addressable section is allocatable, so if STACK_FRAME_NON_STANDARD() and __ADDRESSABLE() are used, the section gets renamed and never discarded: ld: warning: orphan section `.init.discard.addressable' from `vmlinux.o' being placed in section `.init.discard.addressable' The section is also a problem for the stub's absolute relocation check on some arches. In preparation for using STACK_FRAME_NON_STANDARD() in libstub code, remove the section for both cases. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> --- drivers/firmware/efi/libstub/Makefile | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 77a2b2d74f3f6..0d5d99c3cacdd 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile@@ -155,6 +155,11 @@ STUBCOPY_FLAGS-$(CONFIG_LOONGARCH) += --prefix-alloc-sections=.init \ --prefix-symbols=__efistub_ STUBCOPY_RELOC-$(CONFIG_LOONGARCH) := R_LARCH_MARK_LA +# Drop the section created by __ADDRESSABLE() from the absolute symbol check +# and the objcopy, otherwise it gets prefixed and doesn't get discared. +STUBCOPY_RM_SECTIONS := --remove-section=.discard.addressable +STUBCOPY_FLAGS-y += $(STUBCOPY_RM_SECTIONS) + $(obj)/%.stub.o: $(obj)/%.o FORCE $(call if_changed,stubcopy)
@@ -166,7 +171,7 @@ $(obj)/%.stub.o: $(obj)/%.o FORCE # quiet_cmd_stubcopy = STUBCPY $@ cmd_stubcopy = \ - $(STRIP) --strip-debug -o $@ $<; \ + $(STRIP) --strip-debug $(STUBCOPY_RM_SECTIONS) -o $@ $<; \ if $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y); then \ echo "$@: absolute symbol references not allowed in the EFI stub" >&2; \ /bin/false; \
--
2.55.0