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authorMarc Zyngier <maz@kernel.org>2020-07-22 17:22:31 +0100
committerMarc Zyngier <maz@kernel.org>2020-07-28 09:03:57 +0100
commitbf4086b1a1efa3d3a2c17582e00bbd2176dfe177 (patch)
treecf28052876eca7fa9986481ab04692a3ab45dbcc
parentb9e10d4a6c9f5cbe6369ce2c17ebc67d2e5a4be5 (diff)
KVM: arm64: Prevent vcpu_has_ptrauth from generating OOL functions
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@gmail.com> Reported-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://lore.kernel.org/r/20200722162231.3689767-1-maz@kernel.org
-rw-r--r--arch/arm64/include/asm/kvm_host.h11
1 files 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)