diff options
| author | Will Deacon <will.deacon@arm.com> | 2018-01-03 12:46:21 +0000 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-01-08 18:47:05 +0000 |
| commit | aa6acde65e03186b5add8151e1ffe36c3c62639b (patch) | |
| tree | 450d9b380f76a8f33afb5a07dffe3229f6aa4d48 /arch/arm64/kernel/cpu_errata.c | |
| parent | a65d219fe5dc7887fd5ca04c2ac3e9a34feb8dfc (diff) | |
arm64: Implement branch predictor hardening for affected Cortex-A CPUs
Cortex-A57, A72, A73 and A75 are susceptible to branch predictor aliasing
and can theoretically be attacked by malicious code.
This patch implements a PSCI-based mitigation for these CPUs when available.
The call into firmware will invalidate the branch predictor state, preventing
any malicious entries from affecting other victim contexts.
Co-developed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/cpu_errata.c')
| -rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 16ea5c6f314e..cb0fb3796bb8 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -53,6 +53,8 @@ static int cpu_enable_trap_ctr_access(void *__unused) DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); #ifdef CONFIG_KVM +extern char __psci_hyp_bp_inval_start[], __psci_hyp_bp_inval_end[]; + static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start, const char *hyp_vecs_end) { @@ -94,6 +96,9 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, spin_unlock(&bp_lock); } #else +#define __psci_hyp_bp_inval_start NULL +#define __psci_hyp_bp_inval_end NULL + static void __install_bp_hardening_cb(bp_hardening_cb_t fn, const char *hyp_vecs_start, const char *hyp_vecs_end) @@ -118,6 +123,21 @@ static void install_bp_hardening_cb(const struct arm64_cpu_capabilities *entry, __install_bp_hardening_cb(fn, hyp_vecs_start, hyp_vecs_end); } + +#include <linux/psci.h> + +static int enable_psci_bp_hardening(void *data) +{ + const struct arm64_cpu_capabilities *entry = data; + + if (psci_ops.get_version) + install_bp_hardening_cb(entry, + (bp_hardening_cb_t)psci_ops.get_version, + __psci_hyp_bp_inval_start, + __psci_hyp_bp_inval_end); + + return 0; +} #endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */ #define MIDR_RANGE(model, min, max) \ @@ -261,6 +281,28 @@ const struct arm64_cpu_capabilities arm64_errata[] = { MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), }, #endif +#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR + { + .capability = ARM64_HARDEN_BRANCH_PREDICTOR, + MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), + .enable = enable_psci_bp_hardening, + }, + { + .capability = ARM64_HARDEN_BRANCH_PREDICTOR, + MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), + .enable = enable_psci_bp_hardening, + }, + { + .capability = ARM64_HARDEN_BRANCH_PREDICTOR, + MIDR_ALL_VERSIONS(MIDR_CORTEX_A73), + .enable = enable_psci_bp_hardening, + }, + { + .capability = ARM64_HARDEN_BRANCH_PREDICTOR, + MIDR_ALL_VERSIONS(MIDR_CORTEX_A75), + .enable = enable_psci_bp_hardening, + }, +#endif { } }; |