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
232
233
234
235
236
237
238
239
240
241
242
243
244
245
|
#include "frida-gumjs.h"
#include "instrument.h"
#include "util.h"
#if defined(__arm__)
#define PAGE_MASK (~(GUM_ADDRESS(0xfff)))
#define PAGE_ALIGNED(x) ((GUM_ADDRESS(x) & PAGE_MASK) == GUM_ADDRESS(x))
gboolean instrument_cache_enabled = FALSE;
gsize instrument_cache_size = 0;
extern __thread guint64 instrument_previous_pc;
__attribute__((aligned(0x1000))) static guint8 area_ptr_dummy[MAP_SIZE];
#pragma pack(push, 1)
typedef struct {
// cur_location = (block_address >> 4) ^ (block_address << 8);
// shared_mem[cur_location ^ prev_location]++;
// prev_location = cur_location >> 1;
/* We can remove this branch when we add support for branch suppression */
uint32_t b_code; /* b imm */
uint8_t * shared_mem;
uint64_t *prev_location;
/* code */
/* save regs */
uint32_t str_r0_sp_rz; /* str r0, [sp - RED_ZONE] */
uint32_t str_r1_sp_rz_4; /* str r1, [sp - (RED_ZONE + 4)] */
/* load prev */
uint32_t ldr_r0_pprev; /* ldr r0, [pc-x] */
uint32_t ldrh_r1_r0; /* ldrh r1, [r0] */
/* load curr */
uint32_t mov_r0_block_id; /* mov r0, #imm16 */
/* calculate new */
uint32_t eor_r0_r0_r1; /* eor r0, r0, r1 */
/* load map */
uint32_t ldr_r1_pmap; /* ldr r1, [pc-x] */
/* calculate offset */
uint32_t add_r1_r1_r0; /* add r1, r1, r0 */
/* Load the value */
uint32_t ldrb_r0_r1; /* ldrb r0, [r1] */
/* Increment the value */
uint32_t add_r0_r0_1; /* add r0, r0, #1 */
uint32_t add_r0_r0_r0_lsr_8; /* add r0, r0, r0, lsr #8 */
/* Save the value */
uint32_t strb_r0_r1; /* strb r0, [r1] */
/* load curr shifted */
uint32_t mov_r0_block_id_shr_1; /* mov r0, #imm16 >> 1*/
/* Update prev */
uint32_t ldr_r1_pprev; /* ldr r1, [pc-x] */
uint32_t strh_r0_r1; /* strh r0, [r1] */
/* restore regs */
uint32_t ldr_r1_sp_rz_4; /* ldr r1, [sp - (RED_ZONE + 4)] */
uint32_t ldr_r0_sp_rz; /* ldr r0, [sp - RED_ZONE] */
} afl_log_code_asm_t;
typedef union {
afl_log_code_asm_t code;
uint8_t bytes[0];
} afl_log_code;
#pragma pack(pop)
static const afl_log_code_asm_t template =
{
.b_code = GUINT32_TO_LE(0xea000001),
.shared_mem = (uint8_t *)GUINT32_TO_LE(0xcefaadde),
.prev_location = (uint64_t *)GUINT32_TO_LE(0xadba0df0),
.str_r0_sp_rz = GUINT32_TO_LE(0xe50d0080),
.str_r1_sp_rz_4 = GUINT32_TO_LE(0xe50d1084),
.ldr_r0_pprev = GUINT32_TO_LE(0xe51f0014),
.ldrh_r1_r0 = GUINT32_TO_LE(0xe1d010b0),
.mov_r0_block_id = GUINT32_TO_LE(0xe3000000),
.eor_r0_r0_r1 = GUINT32_TO_LE(0xe0200001),
.ldr_r1_pmap = GUINT32_TO_LE(0xe51f1028),
.add_r1_r1_r0 = GUINT32_TO_LE(0xe0811000),
.ldrb_r0_r1 = GUINT32_TO_LE(0xe5d10000),
.add_r0_r0_1 = GUINT32_TO_LE(0xe2800001),
.add_r0_r0_r0_lsr_8 = GUINT32_TO_LE(0xe0800420),
.strb_r0_r1 = GUINT32_TO_LE(0xe5c10000),
.mov_r0_block_id_shr_1 = GUINT32_TO_LE(0xe3000000),
.ldr_r1_pprev = GUINT32_TO_LE(0xe51f1040),
.strh_r0_r1 = GUINT32_TO_LE(0xe1c100b0),
.ldr_r1_sp_rz_4 = GUINT32_TO_LE(0xe51d1084),
.ldr_r0_sp_rz = GUINT32_TO_LE(0xe51d0080),
}
;
gboolean instrument_is_coverage_optimize_supported(void) {
return true;
}
static void patch_t3_insn(uint32_t *insn, uint16_t val) {
uint32_t orig = GUINT32_FROM_LE(*insn);
uint32_t imm12 = (val & 0xfff);
uint32_t imm4 = (val >> 12);
orig |= imm12;
orig |= (imm4 << 16);
*insn = GUINT32_TO_LE(orig);
}
void instrument_coverage_optimize(const cs_insn *instr,
GumStalkerOutput *output) {
afl_log_code code = {0};
GumArmWriter *cw = output->writer.arm;
gpointer block_start;
guint64 area_offset = instrument_get_offset_hash(GUM_ADDRESS(instr->address));
gsize map_size_pow2;
gsize area_offset_ror;
GumAddress code_addr = 0;
// gum_arm64_writer_put_brk_imm(cw, 0x0);
code_addr = cw->pc;
block_start = GSIZE_TO_POINTER(GUM_ADDRESS(cw->code));
code.code = template;
g_assert(PAGE_ALIGNED(__afl_area_ptr));
map_size_pow2 = util_log2(__afl_map_size);
area_offset_ror = util_rotate(area_offset, 1, map_size_pow2);
code.code.shared_mem = __afl_area_ptr;
code.code.prev_location = instrument_previous_pc_addr;
patch_t3_insn(&code.code.mov_r0_block_id, (uint16_t)area_offset);
patch_t3_insn(&code.code.mov_r0_block_id_shr_1, (uint16_t)area_offset_ror);
// gum_arm_writer_put_breakpoint(cw);
gum_arm_writer_put_bytes(cw, code.bytes, sizeof(afl_log_code));
}
void instrument_coverage_optimize_insn(const cs_insn *instr,
GumStalkerOutput *output) {
UNUSED_PARAMETER(instr);
UNUSED_PARAMETER(output);
}
void instrument_coverage_optimize_init(void) {
char *shm_env = getenv(SHM_ENV_VAR);
FVERBOSE("SHM_ENV_VAR: %s", shm_env);
if (shm_env == NULL) {
FWARNF("SHM_ENV_VAR not set, using dummy for debugging purposes");
__afl_area_ptr = area_ptr_dummy;
memset(area_ptr_dummy, '\0', sizeof(area_ptr_dummy));
}
FVERBOSE("__afl_area_ptr: %p", __afl_area_ptr);
if (instrument_previous_pc_addr == NULL) {
instrument_previous_pc_addr = &instrument_previous_pc;
*instrument_previous_pc_addr = instrument_hash_zero;
FVERBOSE("instrument_previous_pc_addr: %p", instrument_previous_pc_addr);
}
}
void instrument_flush(GumStalkerOutput *output) {
if (output->encoding == GUM_INSTRUCTION_SPECIAL) {
gum_thumb_writer_flush(output->writer.thumb);
} else {
gum_arm_writer_flush(output->writer.arm);
}
}
gpointer instrument_cur(GumStalkerOutput *output) {
return gum_arm_writer_cur(output->writer.arm);
}
void instrument_cache_config(void) {
}
void instrument_cache_init(void) {
}
void instrument_cache_insert(gpointer real_address, gpointer code_address) {
UNUSED_PARAMETER(real_address);
UNUSED_PARAMETER(code_address);
}
void instrument_cache(const cs_insn *instr, GumStalkerOutput *output) {
UNUSED_PARAMETER(instr);
UNUSED_PARAMETER(output);
}
void instrument_write_regs(GumCpuContext *cpu_context, gpointer user_data) {
int fd = (int)user_data;
instrument_regs_format(fd,
"r0 : 0x%08x, r1 : 0x%08x, r2 : 0x%08x, r3 : 0x%08x\n",
cpu_context->r[0], cpu_context->r[2],
cpu_context->r[1], cpu_context->r[3]);
instrument_regs_format(fd,
"r4 : 0x%08x, r5 : 0x%08x, r6 : 0x%08x, r7 : 0x%08x\n",
cpu_context->r[4], cpu_context->r[5],
cpu_context->r[6], cpu_context->r[7]);
instrument_regs_format(
fd, "r8 : 0x%08x, r9 : 0x%08x, r10: 0x%08x, r11: 0x%08x\n",
cpu_context->r8, cpu_context->r9, cpu_context->r10, cpu_context->r11);
instrument_regs_format(
fd, "r12: 0x%08x, sp : 0x%08x, lr : 0x%08x, pc : 0x%08x\n",
cpu_context->r12, cpu_context->sp, cpu_context->lr, cpu_context->pc);
instrument_regs_format(fd, "cpsr: 0x%08x\n\n", cpu_context->cpsr);
}
#endif
|
