diff options
| author | Shanker Donthineni <shankerd@codeaurora.org> | 2018-01-05 14:28:59 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-16 20:22:54 +0100 |
| commit | 9b26a45c34e40575e53287365be7571b9cda21ab (patch) | |
| tree | 63085b5843ca9881b6cb627498da706a7f72a2e2 /arch/arm64/kernel/cpu_errata.c | |
| parent | 48993dfa1af8c719576a18c0e2ca1d611297e34e (diff) | |
arm64: Implement branch predictor hardening for Falkor
Commit ec82b567a74f upstream.
Falkor is susceptible to branch predictor aliasing and can
theoretically be attacked by malicious code. This patch
implements a mitigation for these attacks, preventing any
malicious entries from affecting other victim contexts.
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
[will: fix label name when !CONFIG_KVM and remove references to MIDR_FALKOR]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/kernel/cpu_errata.c')
| -rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index e09027094f31..54e41dfe41f6 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -68,6 +68,8 @@ 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[]; +extern char __qcom_hyp_sanitize_link_stack_start[]; +extern char __qcom_hyp_sanitize_link_stack_end[]; static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start, const char *hyp_vecs_end) @@ -110,8 +112,10 @@ 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 +#define __psci_hyp_bp_inval_start NULL +#define __psci_hyp_bp_inval_end NULL +#define __qcom_hyp_sanitize_link_stack_start NULL +#define __qcom_hyp_sanitize_link_stack_end NULL static void __install_bp_hardening_cb(bp_hardening_cb_t fn, const char *hyp_vecs_start, @@ -152,6 +156,29 @@ static int enable_psci_bp_hardening(void *data) return 0; } + +static void qcom_link_stack_sanitization(void) +{ + u64 tmp; + + asm volatile("mov %0, x30 \n" + ".rept 16 \n" + "bl . + 4 \n" + ".endr \n" + "mov x30, %0 \n" + : "=&r" (tmp)); +} + +static int qcom_enable_link_stack_sanitization(void *data) +{ + const struct arm64_cpu_capabilities *entry = data; + + install_bp_hardening_cb(entry, qcom_link_stack_sanitization, + __qcom_hyp_sanitize_link_stack_start, + __qcom_hyp_sanitize_link_stack_end); + + return 0; +} #endif /* CONFIG_HARDEN_BRANCH_PREDICTOR */ #define MIDR_RANGE(model, min, max) \ @@ -323,6 +350,15 @@ const struct arm64_cpu_capabilities arm64_errata[] = { MIDR_ALL_VERSIONS(MIDR_CORTEX_A75), .enable = enable_psci_bp_hardening, }, + { + .capability = ARM64_HARDEN_BRANCH_PREDICTOR, + MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1), + .enable = qcom_enable_link_stack_sanitization, + }, + { + .capability = ARM64_HARDEN_BP_POST_GUEST_EXIT, + MIDR_ALL_VERSIONS(MIDR_QCOM_FALKOR_V1), + }, #endif { } |