X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?p=kvmfornfv.git;a=blobdiff_plain;f=kernel%2Fdrivers%2Ffirmware%2Fefi%2Flibstub%2FMakefile;h=3c0467d3688cff14df877fea66d61c3fbb3279bd;hp=280bc0a6336519392fabfd4cb4ffd0f7173d416f;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hpb=f93b97fd65072de626c074dbe099a1fff05ce060

diff --git a/kernel/drivers/firmware/efi/libstub/Makefile b/kernel/drivers/firmware/efi/libstub/Makefile
index 280bc0a63..3c0467d36 100644
--- a/kernel/drivers/firmware/efi/libstub/Makefile
+++ b/kernel/drivers/firmware/efi/libstub/Makefile
@@ -14,6 +14,8 @@ cflags-$(CONFIG_ARM64)		:= $(subst -pg,,$(KBUILD_CFLAGS))
 cflags-$(CONFIG_ARM)		:= $(subst -pg,,$(KBUILD_CFLAGS)) \
 				   -fno-builtin -fpic -mno-single-pic-base
 
+cflags-$(CONFIG_EFI_ARMSTUB)	+= -I$(srctree)/scripts/dtc/libfdt
+
 KBUILD_CFLAGS			:= $(cflags-y) \
 				   $(call cc-option,-ffreestanding) \
 				   $(call cc-option,-fno-stack-protector)
@@ -22,9 +24,18 @@ GCOV_PROFILE			:= n
 KASAN_SANITIZE			:= n
 
 lib-y				:= efi-stub-helper.o
-lib-$(CONFIG_EFI_ARMSTUB)	+= arm-stub.o fdt.o
 
-CFLAGS_fdt.o			+= -I$(srctree)/scripts/dtc/libfdt/
+# include the stub's generic dependencies from lib/ when building for ARM/arm64
+arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c
+
+$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
+	$(call if_changed_rule,cc_o_c)
+
+lib-$(CONFIG_EFI_ARMSTUB)	+= arm-stub.o fdt.o string.o \
+				   $(patsubst %.c,lib-%.o,$(arm-deps))
+
+lib-$(CONFIG_ARM64)		+= arm64-stub.o
+CFLAGS_arm64-stub.o 		:= -DTEXT_OFFSET=$(TEXT_OFFSET)
 
 #
 # arm64 puts the stub in the kernel proper, which will unnecessarily retain all
@@ -32,10 +43,27 @@ CFLAGS_fdt.o			+= -I$(srctree)/scripts/dtc/libfdt/
 # So let's apply the __init annotations at the section level, by prefixing
 # the section names directly. This will ensure that even all the inline string
 # literals are covered.
+# The fact that the stub and the kernel proper are essentially the same binary
+# also means that we need to be extra careful to make sure that the stub does
+# not rely on any absolute symbol references, considering that the virtual
+# kernel mapping that the linker uses is not active yet when the stub is
+# executing. So build all C dependencies of the EFI stub into libstub, and do
+# a verification pass to see if any absolute relocations exist in any of the
+# object files.
 #
-extra-$(CONFIG_ARM64)		:= $(lib-y)
-lib-$(CONFIG_ARM64)		:= $(patsubst %.o,%.init.o,$(lib-y))
+extra-$(CONFIG_EFI_ARMSTUB)	:= $(lib-y)
+lib-$(CONFIG_EFI_ARMSTUB)	:= $(patsubst %.o,%.stub.o,$(lib-y))
+
+STUBCOPY_FLAGS-y		:= -R .debug* -R *ksymtab* -R *kcrctab*
+STUBCOPY_FLAGS-$(CONFIG_ARM64)	+= --prefix-alloc-sections=.init \
+				   --prefix-symbols=__efistub_
+STUBCOPY_RELOC-$(CONFIG_ARM64)	:= R_AARCH64_ABS
+
+$(obj)/%.stub.o: $(obj)/%.o FORCE
+	$(call if_changed,stubcopy)
 
-OBJCOPYFLAGS := --prefix-alloc-sections=.init
-$(obj)/%.init.o: $(obj)/%.o FORCE
-	$(call if_changed,objcopy)
+quiet_cmd_stubcopy = STUBCPY $@
+      cmd_stubcopy = if $(OBJCOPY) $(STUBCOPY_FLAGS-y) $< $@; then	\
+		     $(OBJDUMP) -r $@ | grep $(STUBCOPY_RELOC-y)	\
+		     && (echo >&2 "$@: absolute symbol references not allowed in the EFI stub"; \
+			 rm -f $@; /bin/false); else /bin/false; fi