Since 4.8.3, gcc has enabled -fstack-protector by default. This is
problematic for the KVM selftests as they do not configure fs or gs
segments (the stack canary is pulled from fs:0x28). With the default
behavior, gcc will insert a stack canary on any function that creates
buffers of 8 bytes or more. As a result, ucall() will hit a triple
fault shutdown due to reading a bad fs segment when inserting its
stack canary, i.e. every test fails with an unexpected SHUTDOWN.
Fixes: 14c47b7530e2d ("kvm: selftests: introduce ucall")
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
tools/testing/selftests/kvm/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 3c1f4bdf9000..596c0864d0df 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -29,7 +29,7 @@ LIBKVM += $(LIBKVM_$(UNAME_M))
INSTALL_HDR_PATH = $(top_srcdir)/usr
LINUX_HDR_PATH = $(INSTALL_HDR_PATH)/include/
LINUX_TOOL_INCLUDE = $(top_srcdir)/tools/include
-CFLAGS += -O2 -g -std=gnu99 -I$(LINUX_TOOL_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude -I$(<D) -Iinclude/$(UNAME_M) -I..
+CFLAGS += -O2 -g -std=gnu99 -fno-stack-protector -I$(LINUX_TOOL_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude -I$(<D) -Iinclude/$(UNAME_M) -I..
LDFLAGS += -pthread
# After inclusion, $(OUTPUT) is defined and
--
2.21.0
