1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _X86_ENCLS_H
#define _X86_ENCLS_H
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/rwsem.h>
#include <linux/types.h>
#include <asm/asm.h>
#include <asm/traps.h>
#include "sgx.h"
enum sgx_encls_function {
ECREATE = 0x00,
EADD = 0x01,
EINIT = 0x02,
EREMOVE = 0x03,
EDGBRD = 0x04,
EDGBWR = 0x05,
EEXTEND = 0x06,
ELDU = 0x08,
EBLOCK = 0x09,
EPA = 0x0A,
EWB = 0x0B,
ETRACK = 0x0C,
};
/**
* ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
*
* ENCLS has its own (positive value) error codes and also generates
* ENCLS specific #GP and #PF faults. And the ENCLS values get munged
* with system error codes as everything percolates back up the stack.
* Unfortunately (for us), we need to precisely identify each unique
* error code, e.g. the action taken if EWB fails varies based on the
* type of fault and on the exact SGX error code, i.e. we can't simply
* convert all faults to -EFAULT.
*
* To make all three error types coexist, we set bit 30 to identify an
* ENCLS fault. Bit 31 (technically bits N:31) is used to differentiate
* between positive (faults and SGX error codes) and negative (system
* error codes) values.
*/
#define ENCLS_FAULT_FLAG 0x40000000
/* Retrieve the encoded trapnr from the specified return code. */
#define ENCLS_TRAPNR(r) ((r) & ~ENCLS_FAULT_FLAG)
/* Issue a WARN() about an ENCLS function. */
#define ENCLS_WARN(r, name) { \
do { \
int _r = (r); \
WARN_ONCE(_r, "%s returned %d (0x%x)\n", (name), _r, _r); \
} while (0); \
}
/**
* encls_failed() - Check if an ENCLS function failed
* @ret: the return value of an ENCLS function call
*
* Check if an ENCLS function failed. This happens when the function causes a
* fault that is not caused by an EPCM conflict or when the function returns a
* non-zero value.
*/
static inline bool encls_failed(int ret)
{
if (ret & ENCLS_FAULT_FLAG)
return ENCLS_TRAPNR(ret) != X86_TRAP_PF;
return !!ret;
}
/**
* __encls_ret_N - encode an ENCLS function that returns an error code in EAX
* @rax: function number
* @inputs: asm inputs for the function
*
* Emit assembly for an ENCLS function that returns an error code, e.g. EREMOVE.
* And because SGX isn't complex enough as it is, function that return an error
* code also modify flags.
*
* Return:
* 0 on success,
* SGX error code on failure
*/
#define __encls_ret_N(rax, inputs...) \
({ \
int ret; \
asm volatile( \
"1: .byte 0x0f, 0x01, 0xcf;\n\t" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \
" jmp 2b\n" \
".previous\n" \
_ASM_EXTABLE_FAULT(1b, 3b) \
: "=a"(ret) \
: "a"(rax), inputs \
: "memory", "cc"); \
ret; \
})
#define __encls_ret_1(rax, rcx) \
({ \
__encls_ret_N(rax, "c"(rcx)); \
})
#define __encls_ret_2(rax, rbx, rcx) \
({ \
__encls_ret_N(rax, "b"(rbx), "c"(rcx)); \
})
#define __encls_ret_3(rax, rbx, rcx, rdx) \
({ \
__encls_ret_N(rax, "b"(rbx), "c"(rcx), "d"(rdx)); \
})
/**
* __encls_N - encode an ENCLS function that doesn't return an error code
* @rax: function number
* @rbx_out: optional output variable
* @inputs: asm inputs for the function
*
* Emit assembly for an ENCLS function that does not return an error code, e.g.
* ECREATE. Leaves without error codes either succeed or fault. @rbx_out is an
* optional parameter for use by EDGBRD, which returns the requested value in
* RBX.
*
* Return:
* 0 on success,
* trapnr with ENCLS_FAULT_FLAG set on fault
*/
#define __encls_N(rax, rbx_out, inputs...) \
({ \
int ret; \
asm volatile( \
"1: .byte 0x0f, 0x01, 0xcf;\n\t" \
" xor %%eax,%%eax;\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
"3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \
" jmp 2b\n" \
".previous\n" \
_ASM_EXTABLE_FAULT(1b, 3b) \
: "=a"(ret), "=b"(rbx_out) \
: "a"(rax), inputs \
: "memory"); \
ret; \
})
#define __encls_2(rax, rbx, rcx) \
({ \
unsigned long ign_rbx_out; \
__encls_N(rax, ign_rbx_out, "b"(rbx), "c"(rcx)); \
})
#define __encls_1_1(rax, data, rcx) \
({ \
unsigned long rbx_out; \
int ret = __encls_N(rax, rbx_out, "c"(rcx)); \
if (!ret) \
data = rbx_out; \
ret; \
})
static inline int __ecreate(struct sgx_pageinfo *pginfo, void *secs)
{
return __encls_2(ECREATE, pginfo, secs);
}
static inline int __eextend(void *secs, void *addr)
{
return __encls_2(EEXTEND, secs, addr);
}
static inline int __eadd(struct sgx_pageinfo *pginfo, void *addr)
{
return __encls_2(EADD, pginfo, addr);
}
static inline int __einit(void *sigstruct, void *token, void *secs)
{
return __encls_ret_3(EINIT, sigstruct, secs, token);
}
static inline int __eremove(void *addr)
{
return __encls_ret_1(EREMOVE, addr);
}
static inline int __edbgwr(void *addr, unsigned long *data)
{
return __encls_2(EDGBWR, *data, addr);
}
static inline int __edbgrd(void *addr, unsigned long *data)
{
return __encls_1_1(EDGBRD, *data, addr);
}
static inline int __etrack(void *addr)
{
return __encls_ret_1(ETRACK, addr);
}
static inline int __eldu(struct sgx_pageinfo *pginfo, void *addr,
void *va)
{
return __encls_ret_3(ELDU, pginfo, addr, va);
}
static inline int __eblock(void *addr)
{
return __encls_ret_1(EBLOCK, addr);
}
static inline int __epa(void *addr)
{
unsigned long rbx = SGX_PAGE_TYPE_VA;
return __encls_2(EPA, rbx, addr);
}
static inline int __ewb(struct sgx_pageinfo *pginfo, void *addr,
void *va)
{
return __encls_ret_3(EWB, pginfo, addr, va);
}
#endif /* _X86_ENCLS_H */
|
