efi/libstub: zboot: Avoid eager evaluation of objcopy flags

The Make variable containing the objcopy flags may be constructed from
the output of build tools operating on build artifacts, and these may
not exist when doing a make clean.

So avoid evaluating them eagerly, to prevent spurious build warnings.

Suggested-by: Pedro Falcato <pedro.falcato@gmail.com>
Tested-by: Alan Bartlett <ajb@elrepo.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/firmware/efi/libstub/Makefile.zboot b/drivers/firmware/efi/libstub/Makefile.zboot
index 89ef820f3b34483a55cd6f9b30043910922da75e..2c489627a8078945f26071644cc5e5390c2ee0d9 100644 (file)
--- a/drivers/firmware/efi/libstub/Makefile.zboot
+++ b/drivers/firmware/efi/libstub/Makefile.zboot
@@ -32,7 +32,8 @@ zboot-size-len-$(CONFIG_KERNEL_GZIP)   := 0
 $(obj)/vmlinuz: $(obj)/vmlinux.bin FORCE
        $(call if_changed,$(zboot-method-y))
 
-OBJCOPYFLAGS_vmlinuz.o := -I binary -O $(EFI_ZBOOT_BFD_TARGET) $(EFI_ZBOOT_OBJCOPY_FLAGS) \
+# avoid eager evaluation to prevent references to non-existent build artifacts
+OBJCOPYFLAGS_vmlinuz.o = -I binary -O $(EFI_ZBOOT_BFD_TARGET) $(EFI_ZBOOT_OBJCOPY_FLAGS) \
                          --rename-section .data=.gzdata,load,alloc,readonly,contents
 $(obj)/vmlinuz.o: $(obj)/vmlinuz FORCE
        $(call if_changed,objcopy)