From bad682e26d6a0345cc0c12dabb340e2545f135ad Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 9 Mar 2018 15:40:50 +0000 Subject: [PATCH] arm64: Relax ARM_SMCCC_ARCH_WORKAROUND_1 discovery [ Upstream commit e21da1c992007594d391e7b301779cf30f438691 ] 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: b092201e0020 ("arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support") Signed-off-by: Marc Zyngier Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/cpu_errata.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 52f15cd..b5a2833 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -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; -- 2.7.4