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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
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
51static 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
57static 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
70static 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
83static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
84 unsigned int *ecx, unsigned int *edx)
85{
86 /* ecx is often an input as well as an output. */
87 asm volatile(
88 "cpuid;"
89 : "=a" (*eax),
90 "=b" (*ebx),
91 "=c" (*ecx),
92 "=d" (*edx)
93 : "0" (*eax), "2" (*ecx));
94}
95
96/* Intel-defined CPU features, CPUID level 0x00000007:0 (ecx) */
97#define X86_FEATURE_PKU (1<<3) /* Protection Keys for Userspace */
98#define X86_FEATURE_OSPKE (1<<4) /* OS Protection Keys Enable */
99
100static inline int cpu_has_pkeys(void)
101{
102 unsigned int eax;
103 unsigned int ebx;
104 unsigned int ecx;
105 unsigned int edx;
106
107 eax = 0x7;
108 ecx = 0x0;
109 __cpuid(&eax, &ebx, &ecx, &edx);
110
111 if (!(ecx & X86_FEATURE_PKU)) {
112 dprintf2("cpu does not have PKU\n");
113 return 0;
114 }
115 if (!(ecx & X86_FEATURE_OSPKE)) {
116 dprintf2("cpu does not have OSPKE\n");
117 return 0;
118 }
119 return 1;
120}
121
122static inline u32 pkey_bit_position(int pkey)
123{
124 return pkey * PKEY_BITS_PER_PKEY;
125}
126
127#define XSTATE_PKEY_BIT (9)
128#define XSTATE_PKEY 0x200
129#define XSTATE_BV_OFFSET 512
130
131int pkey_reg_xstate_offset(void)
132{
133 unsigned int eax;
134 unsigned int ebx;
135 unsigned int ecx;
136 unsigned int edx;
137 int xstate_offset;
138 int xstate_size;
139 unsigned long XSTATE_CPUID = 0xd;
140 int leaf;
141
142 /* assume that XSTATE_PKEY is set in XCR0 */
143 leaf = XSTATE_PKEY_BIT;
144 {
145 eax = XSTATE_CPUID;
146 ecx = leaf;
147 __cpuid(&eax, &ebx, &ecx, &edx);
148
149 if (leaf == XSTATE_PKEY_BIT) {
150 xstate_offset = ebx;
151 xstate_size = eax;
152 }
153 }
154
155 if (xstate_size == 0) {
156 printf("could not find size/offset of PKEY in xsave state\n");
157 return 0;
158 }
159
160 return xstate_offset;
161}
162
163static inline int get_arch_reserved_keys(void)
164{
165 return NR_RESERVED_PKEYS;
166}
167
168void expect_fault_on_read_execonly_key(void *p1, int pkey)
169{
170 int ptr_contents;
171
172 ptr_contents = read_ptr(p1);
173 dprintf2("ptr (%p) contents@%d: %x\n", p1, __LINE__, ptr_contents);
174 expected_pkey_fault(pkey);
175}
176
177void *malloc_pkey_with_mprotect_subpage(long size, int prot, u16 pkey)
178{
179 return PTR_ERR_ENOTSUP;
180}
181
182#endif /* _PKEYS_X86_H */