1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | #include <linux/bpf.h> |
3 | #include <linux/cpu.h> |
4 | #include <linux/device.h> |
5 | |
6 | #include <asm/spectre.h> |
7 | |
8 | static bool _unprivileged_ebpf_enabled(void) |
9 | { |
10 | #ifdef CONFIG_BPF_SYSCALL |
11 | return !sysctl_unprivileged_bpf_disabled; |
12 | #else |
13 | return false; |
14 | #endif |
15 | } |
16 | |
17 | ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, |
18 | char *buf) |
19 | { |
20 | return sprintf(buf, fmt: "Mitigation: __user pointer sanitization\n" ); |
21 | } |
22 | |
23 | static unsigned int spectre_v2_state; |
24 | static unsigned int spectre_v2_methods; |
25 | |
26 | void spectre_v2_update_state(unsigned int state, unsigned int method) |
27 | { |
28 | if (state > spectre_v2_state) |
29 | spectre_v2_state = state; |
30 | spectre_v2_methods |= method; |
31 | } |
32 | |
33 | ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, |
34 | char *buf) |
35 | { |
36 | const char *method; |
37 | |
38 | if (spectre_v2_state == SPECTRE_UNAFFECTED) |
39 | return sprintf(buf, fmt: "%s\n" , "Not affected" ); |
40 | |
41 | if (spectre_v2_state != SPECTRE_MITIGATED) |
42 | return sprintf(buf, fmt: "%s\n" , "Vulnerable" ); |
43 | |
44 | if (_unprivileged_ebpf_enabled()) |
45 | return sprintf(buf, fmt: "Vulnerable: Unprivileged eBPF enabled\n" ); |
46 | |
47 | switch (spectre_v2_methods) { |
48 | case SPECTRE_V2_METHOD_BPIALL: |
49 | method = "Branch predictor hardening" ; |
50 | break; |
51 | |
52 | case SPECTRE_V2_METHOD_ICIALLU: |
53 | method = "I-cache invalidation" ; |
54 | break; |
55 | |
56 | case SPECTRE_V2_METHOD_SMC: |
57 | case SPECTRE_V2_METHOD_HVC: |
58 | method = "Firmware call" ; |
59 | break; |
60 | |
61 | case SPECTRE_V2_METHOD_LOOP8: |
62 | method = "History overwrite" ; |
63 | break; |
64 | |
65 | default: |
66 | method = "Multiple mitigations" ; |
67 | break; |
68 | } |
69 | |
70 | return sprintf(buf, fmt: "Mitigation: %s\n" , method); |
71 | } |
72 | |