1/* SPDX-License-Identifier: GPL-2.0 */
2
3#ifndef _PKEYS_X86_H
4#define _PKEYS_X86_H
5
6#ifdef __i386__
7
8#define REG_IP_IDX		REG_EIP
9#define si_pkey_offset		0x14
10
11#else
12
13#define REG_IP_IDX		REG_RIP
14#define si_pkey_offset		0x20
15
16#endif
17
18#ifndef PKEY_DISABLE_ACCESS
19# define PKEY_DISABLE_ACCESS	0x1
20#endif
21
22#ifndef PKEY_DISABLE_WRITE
23# define PKEY_DISABLE_WRITE	0x2
24#endif
25
26#define NR_PKEYS		16
27#define NR_RESERVED_PKEYS	2 /* pkey-0 and exec-only-pkey */
28#define PKEY_BITS_PER_PKEY	2
29#define HPAGE_SIZE		(1UL<<21)
30#define PAGE_SIZE		4096
31#define MB			(1<<20)
32
33static inline void __page_o_noops(void)
34{
35	/* 8-bytes of instruction * 512 bytes = 1 page */
36	asm(".rept 512 ; nopl 0x7eeeeeee(%eax) ; .endr");
37}
38
39static inline u64 __read_pkey_reg(void)
40{
41	unsigned int eax, edx;
42	unsigned int ecx = 0;
43	unsigned pkey_reg;
44
45	asm volatile(".byte 0x0f,0x01,0xee\n\t"
46		     : "=a" (eax), "=d" (edx)
47		     : "c" (ecx));
48	pkey_reg = eax;
49	return pkey_reg;
50}
51
52static inline void __write_pkey_reg(u64 pkey_reg)
53{
54	unsigned int eax = pkey_reg;
55	unsigned int ecx = 0;
56	unsigned int edx = 0;
57
58	dprintf4("%s() changing %016llx to %016llx\n", __func__,
59			__read_pkey_reg(), pkey_reg);
60	asm volatile(".byte 0x0f,0x01,0xef\n\t"
61		     : : "a" (eax), "c" (ecx), "d" (edx));
62	assert(pkey_reg == __read_pkey_reg());
63}
64
65/* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx) */
66#define X86_FEATURE_PKU        (1<<3) /* Protection Keys for Userspace */
67#define X86_FEATURE_OSPKE      (1<<4) /* OS Protection Keys Enable */
68
69static inline int cpu_has_pkeys(void)
70{
71	unsigned int eax;
72	unsigned int ebx;
73	unsigned int ecx;
74	unsigned int edx;
75
76	__cpuid_count(0x7, 0x0, eax, ebx, ecx, edx);
77
78	if (!(ecx & X86_FEATURE_PKU)) {
79		dprintf2("cpu does not have PKU\n");
80		return 0;
81	}
82	if (!(ecx & X86_FEATURE_OSPKE)) {
83		dprintf2("cpu does not have OSPKE\n");
84		return 0;
85	}
86	return 1;
87}
88
89static inline int cpu_max_xsave_size(void)
90{
91	unsigned long XSTATE_CPUID = 0xd;
92	unsigned int eax;
93	unsigned int ebx;
94	unsigned int ecx;
95	unsigned int edx;
96
97	__cpuid_count(XSTATE_CPUID, 0, eax, ebx, ecx, edx);
98	return ecx;
99}
100
101static inline u32 pkey_bit_position(int pkey)
102{
103	return pkey * PKEY_BITS_PER_PKEY;
104}
105
106#define XSTATE_PKEY_BIT	(9)
107#define XSTATE_PKEY	0x200
108#define XSTATE_BV_OFFSET	512
109
110int pkey_reg_xstate_offset(void)
111{
112	unsigned int eax;
113	unsigned int ebx;
114	unsigned int ecx;
115	unsigned int edx;
116	int xstate_offset;
117	int xstate_size = 0;
118	unsigned long XSTATE_CPUID = 0xd;
119	int leaf;
120
121	/* assume that XSTATE_PKEY is set in XCR0 */
122	leaf = XSTATE_PKEY_BIT;
123	{
124		__cpuid_count(XSTATE_CPUID, leaf, eax, ebx, ecx, edx);
125
126		if (leaf == XSTATE_PKEY_BIT) {
127			xstate_offset = ebx;
128			xstate_size = eax;
129		}
130	}
131
132	if (xstate_size == 0) {
133		printf("could not find size/offset of PKEY in xsave state\n");
134		return 0;
135	}
136
137	return xstate_offset;
138}
139
140static inline int get_arch_reserved_keys(void)
141{
142	return NR_RESERVED_PKEYS;
143}
144
145void expect_fault_on_read_execonly_key(void *p1, int pkey)
146{
147	int ptr_contents;
148
149	ptr_contents = read_ptr(p1);
150	dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
151	expected_pkey_fault(pkey);
152}
153
154void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
155{
156	return PTR_ERR_ENOTSUP;
157}
158
159#endif /* _PKEYS_X86_H */
160