These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / drivers / firmware / efi / libstub / Makefile

diff --git a/kernel/drivers/firmware/efi/libstub/Makefile b/kernel/drivers/firmware/efi/libstub/Makefile
index 280bc0a..3c0467d 100644 (file)
--- 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