[PATCH v6 01/12] KVM: arm64: Don't depend on fallthrough to hide SYSTEM_RESET2

From: Oliver Upton
Date: Tue May 03 2022 - 23:25:06 EST


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@xxxxxxxxxx>
Reviewed-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
---
arch/arm64/kvm/psci.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
index 708d80e8e60d..67fbd6ef022c 100644
--- 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);
}
--
2.36.0.464.gb9c8b46e94-goog