KVM: arm64: Don't depend on fallthrough to hide SYSTEM_RESET2

Depending on a fallthrough to the default case for hiding SYSTEM_RESET2
requires that any new case statements clean up the failure path for this
PSCI call.

Unhitch SYSTEM_RESET2 from the default case by setting val to
PSCI_RET_NOT_SUPPORTED outside of the switch statement. Apply the
cleanup to both the PSCI_1_1_FN_SYSTEM_RESET2 and
PSCI_1_0_FN_PSCI_FEATURES handlers.

No functional change intended.

Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220504032446.4133305-2-oupton@google.com

diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 708d80e..67fbd6e 100644 (file)
--- a/arch/arm64/kvm/psci.c
+++ b/arch/arm64/kvm/psci.c
@@ -305,9 +305,9 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 
 static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)
 {
+       unsigned long val = PSCI_RET_NOT_SUPPORTED;
        u32 psci_fn = smccc_get_function(vcpu);
        u32 arg;
-       unsigned long val;
        int ret = 1;
 
        switch(psci_fn) {
@@ -320,6 +320,8 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)
                if (val)
                        break;
 
+               val = PSCI_RET_NOT_SUPPORTED;
+
                switch(arg) {
                case PSCI_0_2_FN_PSCI_VERSION:
                case PSCI_0_2_FN_CPU_SUSPEND:
@@ -338,13 +340,8 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)
                        break;
                case PSCI_1_1_FN_SYSTEM_RESET2:
                case PSCI_1_1_FN64_SYSTEM_RESET2:
-                       if (minor >= 1) {
+                       if (minor >= 1)
                                val = 0;
-                               break;
-                       }
-                       fallthrough;
-               default:
-                       val = PSCI_RET_NOT_SUPPORTED;
                        break;
                }
                break;
@@ -365,7 +362,7 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor)
                        val = PSCI_RET_INVALID_PARAMS;
                        break;
                }
-               fallthrough;
+               break;
        default:
                return kvm_psci_0_2_call(vcpu);
        }