| 1 | |
| 2 | #include <linux/bpf.h>
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| 3 | #include <linux/cpu.h>
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| 4 | #include <linux/device.h>
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| 5 |
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| 6 | #include <asm/spectre.h>
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| 7 |
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| 8 | static bool _unprivileged_ebpf_enabled(void)
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| 9 | {
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| 10 | #ifdef CONFIG_BPF_SYSCALL
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| 11 | return !sysctl_unprivileged_bpf_disabled;
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| 12 | #else
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| 13 | return false;
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| 14 | #endif
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| 15 | }
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| 16 |
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| 17 | ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr,
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| 18 | char *buf)
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| 19 | {
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| 20 | return sprintf(buf, "Mitigation: __user pointer sanitization\n");
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| 21 | }
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| 22 |
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| 23 | static unsigned int spectre_v2_state;
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| 24 | static unsigned int spectre_v2_methods;
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| 25 |
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| 26 | void spectre_v2_update_state(unsigned int state, unsigned int method)
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| 27 | {
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| 28 | if (state > spectre_v2_state)
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| 29 | spectre_v2_state = state;
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| 30 | spectre_v2_methods |= method;
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| 31 | }
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| 32 |
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| 33 | ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr,
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| 34 | char *buf)
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| 35 | {
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| 36 | const char *method;
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| 37 |
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| 38 | if (spectre_v2_state == SPECTRE_UNAFFECTED)
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| 39 | return sprintf(buf, "%s\n", "Not affected");
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| 40 |
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| 41 | if (spectre_v2_state != SPECTRE_MITIGATED)
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| 42 | return sprintf(buf, "%s\n", "Vulnerable");
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| 43 |
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| 44 | if (_unprivileged_ebpf_enabled())
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| 45 | return sprintf(buf, "Vulnerable: Unprivileged eBPF enabled\n");
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| 46 |
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| 47 | switch (spectre_v2_methods) {
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| 48 | case SPECTRE_V2_METHOD_BPIALL:
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| 49 | method = "Branch predictor hardening";
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| 50 | break;
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| 51 |
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| 52 | case SPECTRE_V2_METHOD_ICIALLU:
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| 53 | method = "I-cache invalidation";
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| 54 | break;
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| 55 |
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| 56 | case SPECTRE_V2_METHOD_SMC:
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| 57 | case SPECTRE_V2_METHOD_HVC:
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| 58 | method = "Firmware call";
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| 59 | break;
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| 60 |
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| 61 | case SPECTRE_V2_METHOD_LOOP8:
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| 62 | method = "History overwrite";
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| 63 | break;
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| 64 |
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| 65 | default:
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| 66 | method = "Multiple mitigations";
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| 67 | break;
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| 68 | }
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| 69 |
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| 70 | return sprintf(buf, "Mitigation: %s\n", method);
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| 71 | }
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