[PATCH kvm-unit-tests] arm64: Compile with -mno-outline-atomics

[Andrew Jones <drjones@redhat.com>]

GCC 10.1.0 introduced the -moutline-atomics option which, when
enabled, use LSE instructions when the processor provides them.
The option is enabled by default and unfortunately causes the
following error at compile time:

 aarch64-linux-gnu-ld: /usr/lib/gcc/aarch64-linux-gnu/10.1.0/libgcc.a(lse-init.o): in function `init_have_lse_atomics':
 lse-init.c:(.text.startup+0xc): undefined reference to `__getauxval'

This is happening because we are linking against our own libcflat which
doesn't implement the function __getauxval().

Disable the use of the out-of-line functions by compiling with
-mno-outline-atomics.

Reported-by: Alexandru Elisei <alexandru.elisei@arm.com>
Tested-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Andrew Jones <drjones@redhat.com>
---
 Makefile           | 11 +++++------
 arm/Makefile.arm64 |  3 +++
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 3ff2f91600f6..0e21a49096ba 100644
--- a/Makefile
+++ b/Makefile
@@ -17,6 +17,11 @@ DESTDIR := $(PREFIX)/share/kvm-unit-tests/
 
 .PHONY: arch_clean clean distclean cscope
 
+# cc-option
+# Usage: OP_CFLAGS+=$(call cc-option, -falign-functions=0, -malign-functions=0)
+cc-option = $(shell if $(CC) -Werror $(1) -S -o /dev/null -xc /dev/null \
+              > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
+
 #make sure env CFLAGS variable is not used
 CFLAGS =
 
@@ -43,12 +48,6 @@ OBJDIRS += $(LIBFDT_objdir)
 #include architecture specific make rules
 include $(SRCDIR)/$(TEST_DIR)/Makefile
 
-# cc-option
-# Usage: OP_CFLAGS+=$(call cc-option, -falign-functions=0, -malign-functions=0)
-
-cc-option = $(shell if $(CC) -Werror $(1) -S -o /dev/null -xc /dev/null \
-              > /dev/null 2>&1; then echo "$(1)"; else echo "$(2)"; fi ;)
-
 COMMON_CFLAGS += -g $(autodepend-flags) -fno-strict-aliasing -fno-common
 COMMON_CFLAGS += -Wall -Wwrite-strings -Wempty-body -Wuninitialized
 COMMON_CFLAGS += -Wignored-qualifiers -Werror
diff --git a/arm/Makefile.arm64 b/arm/Makefile.arm64
index dfd0c56fe8fb..dbc7524d3070 100644
--- a/arm/Makefile.arm64
+++ b/arm/Makefile.arm64
@@ -9,6 +9,9 @@ ldarch = elf64-littleaarch64
 arch_LDFLAGS = -pie -n
 CFLAGS += -mstrict-align
 
+mno_outline_atomics := $(call cc-option, -mno-outline-atomics, "")
+CFLAGS += $(mno_outline_atomics)
+
 define arch_elf_check =
 	$(if $(shell ! $(OBJDUMP) -R $(1) >&/dev/null && echo "nok"),
 		$(error $(shell $(OBJDUMP) -R $(1) 2>&1)))
-- 
2.25.4