1 /* SPDX-License-Identifier: GPL-2.0 */
2
3 #ifndef _PKEYS_X86_H
4 #define _PKEYS_X86_H
5
6 #ifdef __i386__
7
8 #ifndef SYS_mprotect_key
9 # define SYS_mprotect_key 380
10 #endif
11
12 #ifndef SYS_pkey_alloc
13 # define SYS_pkey_alloc 381
14 # define SYS_pkey_free 382
15 #endif
16
17 #define REG_IP_IDX REG_EIP
18 #define si_pkey_offset 0x14
19
20 #else
21
22 #ifndef SYS_mprotect_key
23 # define SYS_mprotect_key 329
24 #endif
25
26 #ifndef SYS_pkey_alloc
27 # define SYS_pkey_alloc 330
28 # define SYS_pkey_free 331
29 #endif
30
31 #define REG_IP_IDX REG_RIP
32 #define si_pkey_offset 0x20
33
34 #endif
35
36 #ifndef PKEY_DISABLE_ACCESS
37 # define PKEY_DISABLE_ACCESS 0x1
38 #endif
39
40 #ifndef PKEY_DISABLE_WRITE
41 # define PKEY_DISABLE_WRITE 0x2
42 #endif
43
44 #define NR_PKEYS 16
45 #define NR_RESERVED_PKEYS 2 /* pkey-0 and exec-only-pkey */
46 #define PKEY_BITS_PER_PKEY 2
47 #define HPAGE_SIZE (1UL<<21)
48 #define PAGE_SIZE 4096
49 #define MB (1<<20)
50
__page_o_noops(void)51 static inline void __page_o_noops(void)
52 {
53 /* 8-bytes of instruction * 512 bytes = 1 page */
54 asm(".rept 512 ; nopl 0x7eeeeeee(%eax) ; .endr");
55 }
56
__read_pkey_reg(void)57 static inline u64 __read_pkey_reg(void)
58 {
59 unsigned int eax, edx;
60 unsigned int ecx = 0;
61 unsigned pkey_reg;
62
63 asm volatile(".byte 0x0f,0x01,0xee\n\t"
64 : "=a" (eax), "=d" (edx)
65 : "c" (ecx));
66 pkey_reg = eax;
67 return pkey_reg;
68 }
69
__write_pkey_reg(u64 pkey_reg)70 static inline void __write_pkey_reg(u64 pkey_reg)
71 {
72 unsigned int eax = pkey_reg;
73 unsigned int ecx = 0;
74 unsigned int edx = 0;
75
76 dprintf4("%s() changing %016llx to %016llx\n", __func__,
77 __read_pkey_reg(), pkey_reg);
78 asm volatile(".byte 0x0f,0x01,0xef\n\t"
79 : : "a" (eax), "c" (ecx), "d" (edx));
80 assert(pkey_reg == __read_pkey_reg());
81 }
82
83 /* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx) */
84 #define X86_FEATURE_PKU (1<<3) /* Protection Keys for Userspace */
85 #define X86_FEATURE_OSPKE (1<<4) /* OS Protection Keys Enable */
86
cpu_has_pkeys(void)87 static inline int cpu_has_pkeys(void)
88 {
89 unsigned int eax;
90 unsigned int ebx;
91 unsigned int ecx;
92 unsigned int edx;
93
94 __cpuid_count(0x7, 0x0, eax, ebx, ecx, edx);
95
96 if (!(ecx & X86_FEATURE_PKU)) {
97 dprintf2("cpu does not have PKU\n");
98 return 0;
99 }
100 if (!(ecx & X86_FEATURE_OSPKE)) {
101 dprintf2("cpu does not have OSPKE\n");
102 return 0;
103 }
104 return 1;
105 }
106
pkey_bit_position(int pkey)107 static inline u32 pkey_bit_position(int pkey)
108 {
109 return pkey * PKEY_BITS_PER_PKEY;
110 }
111
112 #define XSTATE_PKEY_BIT (9)
113 #define XSTATE_PKEY 0x200
114 #define XSTATE_BV_OFFSET 512
115
pkey_reg_xstate_offset(void)116 int pkey_reg_xstate_offset(void)
117 {
118 unsigned int eax;
119 unsigned int ebx;
120 unsigned int ecx;
121 unsigned int edx;
122 int xstate_offset;
123 int xstate_size;
124 unsigned long XSTATE_CPUID = 0xd;
125 int leaf;
126
127 /* assume that XSTATE_PKEY is set in XCR0 */
128 leaf = XSTATE_PKEY_BIT;
129 {
130 __cpuid_count(XSTATE_CPUID, leaf, eax, ebx, ecx, edx);
131
132 if (leaf == XSTATE_PKEY_BIT) {
133 xstate_offset = ebx;
134 xstate_size = eax;
135 }
136 }
137
138 if (xstate_size == 0) {
139 printf("could not find size/offset of PKEY in xsave state\n");
140 return 0;
141 }
142
143 return xstate_offset;
144 }
145
get_arch_reserved_keys(void)146 static inline int get_arch_reserved_keys(void)
147 {
148 return NR_RESERVED_PKEYS;
149 }
150
expect_fault_on_read_execonly_key(void * p1,int pkey)151 void expect_fault_on_read_execonly_key(void *p1, int pkey)
152 {
153 int ptr_contents;
154
155 ptr_contents = read_ptr(p1);
156 dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
157 expected_pkey_fault(pkey);
158 }
159
malloc_pkey_with_mprotect_subpage(long size,int prot,u16 pkey)160 void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
161 {
162 return PTR_ERR_ENOTSUP;
163 }
164
165 #endif /* _PKEYS_X86_H */
166
