arm64: Relax ARM_SMCCC_ARCH_WORKAROUND_1 discovery

A recent update to the ARM SMCCC ARCH_WORKAROUND_1 specification
allows firmware to return a non zero, positive value to describe
that although the mitigation is implemented at the higher exception
level, the CPU on which the call is made is not affected.

Let's relax the check on the return value from ARCH_WORKAROUND_1
so that we only error out if the returned value is negative.

Fixes: b092201e00 ("arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Marc Zyngier 2018-03-09 15:40:50 +00:00 committed by Catalin Marinas
parent b08e5fd90b
commit e21da1c992

View file

@ -178,7 +178,7 @@ static int enable_smccc_arch_workaround_1(void *data)
case PSCI_CONDUIT_HVC:
arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
ARM_SMCCC_ARCH_WORKAROUND_1, &res);
if (res.a0)
if ((int)res.a0 < 0)
return 0;
cb = call_hvc_arch_workaround_1;
smccc_start = __smccc_workaround_1_hvc_start;
@ -188,7 +188,7 @@ static int enable_smccc_arch_workaround_1(void *data)
case PSCI_CONDUIT_SMC:
arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
ARM_SMCCC_ARCH_WORKAROUND_1, &res);
if (res.a0)
if ((int)res.a0 < 0)
return 0;
cb = call_smc_arch_workaround_1;
smccc_start = __smccc_workaround_1_smc_start;