xref: /openbmc/linux/arch/powerpc/kernel/security.c (revision 2359ccdd)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Security related flags and so on.
4 //
5 // Copyright 2018, Michael Ellerman, IBM Corporation.
6 
7 #include <linux/kernel.h>
8 #include <linux/device.h>
9 #include <linux/seq_buf.h>
10 
11 #include <asm/security_features.h>
12 
13 
14 unsigned long powerpc_security_features __read_mostly = SEC_FTR_DEFAULT;
15 
16 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
17 {
18 	bool thread_priv;
19 
20 	thread_priv = security_ftr_enabled(SEC_FTR_L1D_THREAD_PRIV);
21 
22 	if (rfi_flush || thread_priv) {
23 		struct seq_buf s;
24 		seq_buf_init(&s, buf, PAGE_SIZE - 1);
25 
26 		seq_buf_printf(&s, "Mitigation: ");
27 
28 		if (rfi_flush)
29 			seq_buf_printf(&s, "RFI Flush");
30 
31 		if (rfi_flush && thread_priv)
32 			seq_buf_printf(&s, ", ");
33 
34 		if (thread_priv)
35 			seq_buf_printf(&s, "L1D private per thread");
36 
37 		seq_buf_printf(&s, "\n");
38 
39 		return s.len;
40 	}
41 
42 	if (!security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV) &&
43 	    !security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR))
44 		return sprintf(buf, "Not affected\n");
45 
46 	return sprintf(buf, "Vulnerable\n");
47 }
48 
49 ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr, char *buf)
50 {
51 	if (!security_ftr_enabled(SEC_FTR_BNDS_CHK_SPEC_BAR))
52 		return sprintf(buf, "Not affected\n");
53 
54 	return sprintf(buf, "Vulnerable\n");
55 }
56 
57 ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, char *buf)
58 {
59 	bool bcs, ccd, ori;
60 	struct seq_buf s;
61 
62 	seq_buf_init(&s, buf, PAGE_SIZE - 1);
63 
64 	bcs = security_ftr_enabled(SEC_FTR_BCCTRL_SERIALISED);
65 	ccd = security_ftr_enabled(SEC_FTR_COUNT_CACHE_DISABLED);
66 	ori = security_ftr_enabled(SEC_FTR_SPEC_BAR_ORI31);
67 
68 	if (bcs || ccd) {
69 		seq_buf_printf(&s, "Mitigation: ");
70 
71 		if (bcs)
72 			seq_buf_printf(&s, "Indirect branch serialisation (kernel only)");
73 
74 		if (bcs && ccd)
75 			seq_buf_printf(&s, ", ");
76 
77 		if (ccd)
78 			seq_buf_printf(&s, "Indirect branch cache disabled");
79 	} else
80 		seq_buf_printf(&s, "Vulnerable");
81 
82 	if (ori)
83 		seq_buf_printf(&s, ", ori31 speculation barrier enabled");
84 
85 	seq_buf_printf(&s, "\n");
86 
87 	return s.len;
88 }
89