Re: Xen Compilation Error on Ubuntu 20.04

[Jason Andryuk <jandryuk@xxxxxxxxx>]

On Thu, Apr 30, 2020 at 4:18 AM Ayush Dosaj <ayushdosaj2313@xxxxxxxxx> wrote:
>
> Hi Andrew, Xen Development team.
>
> I compiled and installed Xen by appending -fcf-protection=none to CFLAGS on 
> Ubuntu 20.04 but it still crashes on startup.

Ayush, try the patch below.  EMBEDDED_EXTRA_CFLAGS ensures it is set
down in xen/arch/x86/boot/build32.mk

-Jason

diff --git a/Config.mk b/Config.mk
index 0f303c79b2..efb3d42bc4 100644
--- a/Config.mk
+++ b/Config.mk
@@ -205,6 +205,7 @@ APPEND_CFLAGS += $(foreach i, $(APPEND_INCLUDES), -I$(i))

 EMBEDDED_EXTRA_CFLAGS := -nopie -fno-stack-protector -fno-stack-protector-all
 EMBEDDED_EXTRA_CFLAGS += -fno-exceptions
+EMBEDDED_EXTRA_CFLAGS += -fcf-protection=none

 XEN_EXTFILES_URL ?= http://xenbits.xen.org/xen-extfiles
 # All the files at that location were downloaded from elsewhere on
diff --git a/xen/arch/x86/Rules.mk b/xen/arch/x86/Rules.mk
index 4b7ab78467..c3cbae69d2 100644
--- a/xen/arch/x86/Rules.mk
+++ b/xen/arch/x86/Rules.mk
@@ -69,6 +69,7 @@ CFLAGS += -mno-sse $(call cc-option,$(CC),-mskip-rax-setup)
 ifeq ($(CONFIG_INDIRECT_THUNK),y)
 CFLAGS += -mindirect-branch=thunk-extern -mindirect-branch-register
 CFLAGS += -fno-jump-tables
+$(call cc-option-add,CFLAGS,CC,-fcf-protection=none)
 endif

 # If supported by the compiler, reduce stack alignment to 8 bytes. But allow