4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mark Rutland <mark.rutland@xxxxxxx>
From: Jayachandran C <jnair@xxxxxxxxxxxxxxxxxx>
commit f3d795d9b360523beca6d13ba64c2c532f601149 upstream.
Use PSCI based mitigation for speculative execution attacks targeting
the branch predictor. We use the same mechanism as the one used for
Cortex-A CPUs, we expect the PSCI version call to have a side effect
of clearing the BTBs.
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Jayachandran C <jnair@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> [v4.9 backport]
Tested-by: Greg Hackmann <ghackmann@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/kernel/cpu_errata.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -252,6 +252,16 @@ const struct arm64_cpu_capabilities arm6
MIDR_ALL_VERSIONS(MIDR_CORTEX_A75),
.enable = enable_psci_bp_hardening,
},
+ {
+ .capability = ARM64_HARDEN_BRANCH_PREDICTOR,
+ MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
+ .enable = enable_psci_bp_hardening,
+ },
+ {
+ .capability = ARM64_HARDEN_BRANCH_PREDICTOR,
+ MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
+ .enable = enable_psci_bp_hardening,
+ },
#endif
{
}