Messages in this thread Patch in this message |  | | From | Mian Yousaf Kaukab <> | Subject | [PATCH RESEND 4/6] arm64: add sysfs vulnerability show for spectre v2 | Date | Mon, 27 Aug 2018 16:33:08 +0200 |
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Only report mitigation present if hardening callback has been successfully installed.
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de> --- arch/arm64/kernel/cpu_errata.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 92616431ae4e..8469d3be7b15 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -481,7 +481,8 @@ multi_entry_cap_cpu_enable(const struct arm64_cpu_capabilities *entry) caps->cpu_enable(caps); } -#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR +#if defined(CONFIG_HARDEN_BRANCH_PREDICTOR) || \ + defined(CONFIG_GENERIC_CPU_VULNERABILITIES) /* * List of CPUs where we need to issue a psci call to @@ -712,4 +713,35 @@ ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, return sprintf(buf, "Mitigation: __user pointer sanitization\n"); } +ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, + char *buf) +{ + u64 pfr0; + struct bp_hardening_data *data; + + pfr0 = read_cpuid(ID_AA64PFR0_EL1); + if (cpuid_feature_extract_unsigned_field(pfr0, ID_AA64PFR0_CSV2_SHIFT)) + return sprintf(buf, "Not affected\n"); + + if (cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR)) { + /* + * Hardware is vulnerable. Lets check if bp hardening callback + * has been successfully installed + */ + data = arm64_get_bp_hardening_data(); + if (data && data->fn) + return sprintf(buf, + "Mitigation: Branch predictor hardening"); + else + /* For example SMCCC_VERSION_1_0 */ + return sprintf(buf, "Vulnerable\n"); + } + + /* In case CONFIG_HARDEN_BRANCH_PREDICTOR is not enabled */ + if (is_midr_in_range_list(read_cpuid_id(), arm64_bp_harden_smccc_cpus)) + return sprintf(buf, "Vulnerable\n"); + + return sprintf(buf, "Not affected\n"); +} + #endif -- 2.11.0
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