[PATCH v2] kvmtool: Makefile: disable PIE build for bios and pre_init

[PATCH v2] kvmtool: Makefile: disable PIE build for bios and pre_init

[riku.voipio]

From: Riku Voipio <riku.voipio@linaro.org>

Latest Debian and Ubuntu GCC default to PIE code. Disable
PIC for bios and PIE for pre_init. Since the flag -no-pie
is not available on older GCC's, make use of flag only if
the option is available. -fno-pic is more widely available
and should be safe to enable uncondionally.

Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
---
v2: BIOS_FLAGS doesn't need -no-pie so don't set it

 Makefile | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 1f0196f..eeb54a4 100644
--- a/Makefile
+++ b/Makefile
@@ -284,7 +284,7 @@ ifeq ($(call try-build,$(SOURCE_STATIC),$(CFLAGS),$(LDFLAGS) -static),y)
 	GUEST_INIT	:= guest/init
 	GUEST_OBJS	= guest/guest_init.o
 	ifeq ($(ARCH_PRE_INIT),)
-		GUEST_INIT_FLAGS	+= -static
+		GUEST_INIT_FLAGS	+= -static $(PIE_FLAGS)
 	else
 		CFLAGS			+= -DCONFIG_GUEST_PRE_INIT
 		GUEST_INIT_FLAGS	+= -DCONFIG_GUEST_PRE_INIT
@@ -307,6 +307,10 @@ ifeq (y,$(ARCH_WANT_LIBFDT))
 	endif
 endif
 
+ifeq ($(call try-build,$(SOURCE_HELLO),$(CFLAGS),-no-pie),y)
+	PIE_FLAGS	+= -no-pie
+endif
+
 ifneq ($(NOTFOUND),)
         $(warning Skipping optional libraries: $(NOTFOUND))
 endif
@@ -388,7 +392,7 @@ $(PROGRAM_ALIAS): $(PROGRAM)
 ifneq ($(ARCH_PRE_INIT),)
 $(GUEST_PRE_INIT): $(ARCH_PRE_INIT)
 	$(E) "  LINK    " $@
-	$(Q) $(CC) -s -nostdlib $(ARCH_PRE_INIT) -o $@
+	$(Q) $(CC) -s $(PIE_FLAGS) -nostdlib $(ARCH_PRE_INIT) -o $@
 	$(Q) $(LD) -r -b binary -o guest/guest_pre_init.o $(GUEST_PRE_INIT)
 endif
 
@@ -435,6 +439,7 @@ BIOS_CFLAGS += -march=i386
 BIOS_CFLAGS += -mregparm=3
 
 BIOS_CFLAGS += -fno-stack-protector
+BIOS_CFLAGS += -fno-pic
 
 x86/bios.o: x86/bios/bios.bin x86/bios/bios-rom.h
 
-- 
2.10.1