1// SPDX-License-Identifier: GPL-2.0
2/* Copyright(c) 2016-20 Intel Corporation. */
3
4#include <stddef.h>
5#include "defines.h"
6
7/*
8 * Data buffer spanning two pages that will be placed first in the .data
9 * segment via the linker script. Even if not used internally the second page
10 * is needed by external test manipulating page permissions, so mark
11 * encl_buffer as "used" to make sure it is entirely preserved by the compiler.
12 */
13static uint8_t __used __section(".data.encl_buffer") encl_buffer[8192] = { 1 };
14
15enum sgx_enclu_function {
16 EACCEPT = 0x5,
17 EMODPE = 0x6,
18};
19
20static void do_encl_emodpe(void *_op)
21{
22 struct sgx_secinfo secinfo __aligned(sizeof(struct sgx_secinfo)) = {0};
23 struct encl_op_emodpe *op = _op;
24
25 secinfo.flags = op->flags;
26
27 asm volatile(".byte 0x0f, 0x01, 0xd7"
28 : /* no outputs */
29 : "a" (EMODPE),
30 "b" (&secinfo),
31 "c" (op->epc_addr)
32 : "memory" /* read from secinfo pointer */);
33}
34
35static void do_encl_eaccept(void *_op)
36{
37 struct sgx_secinfo secinfo __aligned(sizeof(struct sgx_secinfo)) = {0};
38 struct encl_op_eaccept *op = _op;
39 int rax;
40
41 secinfo.flags = op->flags;
42
43 asm volatile(".byte 0x0f, 0x01, 0xd7"
44 : "=a" (rax)
45 : "a" (EACCEPT),
46 "b" (&secinfo),
47 "c" (op->epc_addr)
48 : "memory" /* read from secinfo pointer */);
49
50 op->ret = rax;
51}
52
53static void *memcpy(void *dest, const void *src, size_t n)
54{
55 size_t i;
56
57 for (i = 0; i < n; i++)
58 ((char *)dest)[i] = ((char *)src)[i];
59
60 return dest;
61}
62
63static void *memset(void *dest, int c, size_t n)
64{
65 size_t i;
66
67 for (i = 0; i < n; i++)
68 ((char *)dest)[i] = c;
69
70 return dest;
71}
72
73static void do_encl_init_tcs_page(void *_op)
74{
75 struct encl_op_init_tcs_page *op = _op;
76 void *tcs = (void *)op->tcs_page;
77 uint32_t val_32;
78
79 memset(dest: tcs, c: 0, n: 16); /* STATE and FLAGS */
80 memcpy(dest: tcs + 16, src: &op->ssa, n: 8); /* OSSA */
81 memset(dest: tcs + 24, c: 0, n: 4); /* CSSA */
82 val_32 = 1;
83 memcpy(dest: tcs + 28, src: &val_32, n: 4); /* NSSA */
84 memcpy(dest: tcs + 32, src: &op->entry, n: 8); /* OENTRY */
85 memset(dest: tcs + 40, c: 0, n: 24); /* AEP, OFSBASE, OGSBASE */
86 val_32 = 0xFFFFFFFF;
87 memcpy(dest: tcs + 64, src: &val_32, n: 4); /* FSLIMIT */
88 memcpy(dest: tcs + 68, src: &val_32, n: 4); /* GSLIMIT */
89 memset(dest: tcs + 72, c: 0, n: 4024); /* Reserved */
90}
91
92static void do_encl_op_put_to_buf(void *op)
93{
94 struct encl_op_put_to_buf *op2 = op;
95
96 memcpy(dest: &encl_buffer[0], src: &op2->value, n: 8);
97}
98
99static void do_encl_op_get_from_buf(void *op)
100{
101 struct encl_op_get_from_buf *op2 = op;
102
103 memcpy(dest: &op2->value, src: &encl_buffer[0], n: 8);
104}
105
106static void do_encl_op_put_to_addr(void *_op)
107{
108 struct encl_op_put_to_addr *op = _op;
109
110 memcpy(dest: (void *)op->addr, src: &op->value, n: 8);
111}
112
113static void do_encl_op_get_from_addr(void *_op)
114{
115 struct encl_op_get_from_addr *op = _op;
116
117 memcpy(dest: &op->value, src: (void *)op->addr, n: 8);
118}
119
120static void do_encl_op_nop(void *_op)
121{
122
123}
124
125/*
126 * Symbol placed at the start of the enclave image by the linker script.
127 * Declare this extern symbol with visibility "hidden" to ensure the compiler
128 * does not access it through the GOT and generates position-independent
129 * addressing as __encl_base(%rip), so we can get the actual enclave base
130 * during runtime.
131 */
132extern const uint8_t __attribute__((visibility("hidden"))) __encl_base;
133
134typedef void (*encl_op_t)(void *);
135static const encl_op_t encl_op_array[ENCL_OP_MAX] = {
136 do_encl_op_put_to_buf,
137 do_encl_op_get_from_buf,
138 do_encl_op_put_to_addr,
139 do_encl_op_get_from_addr,
140 do_encl_op_nop,
141 do_encl_eaccept,
142 do_encl_emodpe,
143 do_encl_init_tcs_page,
144};
145
146void encl_body(void *rdi, void *rsi)
147{
148 struct encl_op_header *header = (struct encl_op_header *)rdi;
149 encl_op_t op;
150
151 if (header->type >= ENCL_OP_MAX)
152 return;
153
154 /*
155 * The enclave base address needs to be added, as this call site
156 * *cannot be* made rip-relative by the compiler, or fixed up by
157 * any other possible means.
158 */
159 op = ((uint64_t)&__encl_base) + encl_op_array[header->type];
160
161 (*op)(header);
162}
163

source code of linux/tools/testing/selftests/sgx/test_encl.c