[PATCH 4.9 117/164] arm64: KVM: Do not use stack-protector to compile EL2 code

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marc Zyngier <marc.zyngier@xxxxxxx>

commit cde13b5dad60471886a3bccb4f4134c647c4a9dc upstream.

We like living dangerously. Nothing explicitely forbids stack-protector
to be used in the EL2 code, while distributions routinely compile their
kernel with it. We're just lucky that no code actually triggers the
instrumentation.

Let's not try our luck for much longer, and disable stack-protector
for code living at EL2.

Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Acked-by: Christoffer Dall <cdall@xxxxxxxxxx>
Signed-off-by: Christoffer Dall <cdall@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/arm64/kvm/hyp/Makefile |    2 ++
 1 file changed, 2 insertions(+)

--- a/arch/arm64/kvm/hyp/Makefile
+++ b/arch/arm64/kvm/hyp/Makefile
@@ -2,6 +2,8 @@
 # Makefile for Kernel-based Virtual Machine module, HYP part
 #
 
+ccflags-y += -fno-stack-protector
+
 KVM=../../../../virt/kvm
 
 obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/vgic-v2-sr.o