So far, vcpu_has_ptrauth() is implemented in terms of system_supports_*_auth()
calls, which are declared "inline". In some specific conditions (clang
and SCS), the "inline" very much turns into an "out of line", which
leads to a fireworks when this predicate is evaluated on a non-VHE
system (right at the beginning of __hyp_handle_ptrauth).
Instead, make sure vcpu_has_ptrauth gets expanded inline by directly
using the cpus_have_final_cap() helpers, which are __always_inline,
generate much better code, and are the only thing that make sense when
running at EL2 on a nVHE system.
Fixes: 29eb5a3c57f7 ("KVM: arm64: Handle PtrAuth traps early")
Reported-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Reported-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Link: https://lore.kernel.org/r/20200722162231.3689767-1-maz@xxxxxxxxxx
---
arch/arm64/include/asm/kvm_host.h | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index c3e6fcc664b1..e21d4a01372f 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -380,9 +380,14 @@ struct kvm_vcpu_arch {
#define vcpu_has_sve(vcpu) (system_supports_sve() && \
((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE))
-#define vcpu_has_ptrauth(vcpu) ((system_supports_address_auth() || \
- system_supports_generic_auth()) && \
- ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH))
+#ifdef CONFIG_ARM64_PTR_AUTH
+#define vcpu_has_ptrauth(vcpu) \
+ ((cpus_have_final_cap(ARM64_HAS_ADDRESS_AUTH) || \
+ cpus_have_final_cap(ARM64_HAS_GENERIC_AUTH)) && \
+ (vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH)
+#else
+#define vcpu_has_ptrauth(vcpu) false
+#endif
#define vcpu_gp_regs(v) (&(v)->arch.ctxt.gp_regs)
--
2.27.0
