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
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
|
/*
american fuzzy lop++ - high-performance binary-only instrumentation
-------------------------------------------------------------------
Originally written by Andrew Griffiths <agriffiths@google.com> and
Michal Zalewski
TCG instrumentation and block chaining support by Andrea Biondo
<andrea.biondo965@gmail.com>
QEMU 3.1.1 port, TCG thread-safety, CompareCoverage and NeverZero
counters by Andrea Fioraldi <andreafioraldi@gmail.com>
Copyright 2015, 2016, 2017 Google Inc. All rights reserved.
Copyright 2019-2020 AFLplusplus Project. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
http://www.apache.org/licenses/LICENSE-2.0
This code is a shim patched into the separately-distributed source
code of QEMU 3.1.0. It leverages the built-in QEMU tracing functionality
to implement AFL-style instrumentation and to take care of the remaining
parts of the AFL fork server logic.
The resulting QEMU binary is essentially a standalone instrumentation
tool; for an example of how to leverage it for other purposes, you can
have a look at afl-showmap.c.
*/
#include "afl-qemu-common.h"
#include "tcg.h"
#include "tcg-op.h"
static void afl_compcov_log_16(target_ulong cur_loc, target_ulong arg1,
target_ulong arg2) {
register uintptr_t idx = cur_loc;
if ((arg1 & 0xff00) == (arg2 & 0xff00)) { INC_AFL_AREA(idx); }
}
static void afl_compcov_log_32(target_ulong cur_loc, target_ulong arg1,
target_ulong arg2) {
register uintptr_t idx = cur_loc;
if ((arg1 & 0xff000000) == (arg2 & 0xff000000)) {
INC_AFL_AREA(idx + 2);
if ((arg1 & 0xff0000) == (arg2 & 0xff0000)) {
INC_AFL_AREA(idx + 1);
if ((arg1 & 0xff00) == (arg2 & 0xff00)) { INC_AFL_AREA(idx); }
}
}
}
static void afl_compcov_log_64(target_ulong cur_loc, target_ulong arg1,
target_ulong arg2) {
register uintptr_t idx = cur_loc;
if ((arg1 & 0xff00000000000000) == (arg2 & 0xff00000000000000)) {
INC_AFL_AREA(idx + 6);
if ((arg1 & 0xff000000000000) == (arg2 & 0xff000000000000)) {
INC_AFL_AREA(idx + 5);
if ((arg1 & 0xff0000000000) == (arg2 & 0xff0000000000)) {
INC_AFL_AREA(idx + 4);
if ((arg1 & 0xff00000000) == (arg2 & 0xff00000000)) {
INC_AFL_AREA(idx + 3);
if ((arg1 & 0xff000000) == (arg2 & 0xff000000)) {
INC_AFL_AREA(idx + 2);
if ((arg1 & 0xff0000) == (arg2 & 0xff0000)) {
INC_AFL_AREA(idx + 1);
if ((arg1 & 0xff00) == (arg2 & 0xff00)) { INC_AFL_AREA(idx); }
}
}
}
}
}
}
}
static void afl_gen_compcov(target_ulong cur_loc, TCGv_i64 arg1, TCGv_i64 arg2,
TCGMemOp ot, int is_imm) {
void *func;
if (!afl_compcov_level || cur_loc > afl_end_code || cur_loc < afl_start_code)
return;
if (!is_imm && afl_compcov_level < 2) return;
switch (ot) {
case MO_64: func = &afl_compcov_log_64; break;
case MO_32: func = &afl_compcov_log_32; break;
case MO_16: func = &afl_compcov_log_16; break;
default: return;
}
cur_loc = (cur_loc >> 4) ^ (cur_loc << 8);
cur_loc &= MAP_SIZE - 7;
if (cur_loc >= afl_inst_rms) return;
tcg_gen_afl_compcov_log_call(func, cur_loc, arg1, arg2);
}
/* Routines for debug */
/*
static void log_x86_saved_gpr(void) {
static const char reg_names[CPU_NB_REGS][4] = {
#ifdef TARGET_X86_64
[R_EAX] = "rax",
[R_EBX] = "rbx",
[R_ECX] = "rcx",
[R_EDX] = "rdx",
[R_ESI] = "rsi",
[R_EDI] = "rdi",
[R_EBP] = "rbp",
[R_ESP] = "rsp",
[8] = "r8",
[9] = "r9",
[10] = "r10",
[11] = "r11",
[12] = "r12",
[13] = "r13",
[14] = "r14",
[15] = "r15",
#else
[R_EAX] = "eax",
[R_EBX] = "ebx",
[R_ECX] = "ecx",
[R_EDX] = "edx",
[R_ESI] = "esi",
[R_EDI] = "edi",
[R_EBP] = "ebp",
[R_ESP] = "esp",
#endif
};
int i;
for (i = 0; i < CPU_NB_REGS; ++i) {
fprintf(stderr, "%s = %lx\n", reg_names[i], persistent_saved_gpr[i]);
}
}
static void log_x86_sp_content(void) {
fprintf(stderr, ">> SP = %lx -> %lx\n", persistent_saved_gpr[R_ESP],
*(unsigned long*)persistent_saved_gpr[R_ESP]);
}*/
#define I386_RESTORE_STATE_FOR_PERSISTENT \
do { \
\
if (persistent_save_gpr) { \
\
int i; \
TCGv_ptr gpr_sv; \
\
TCGv_ptr first_pass_ptr = tcg_const_ptr(&persistent_first_pass); \
TCGv first_pass = tcg_temp_local_new(); \
TCGv one = tcg_const_tl(1); \
tcg_gen_ld8u_tl(first_pass, first_pass_ptr, 0); \
\
TCGLabel *lbl_save_gpr = gen_new_label(); \
TCGLabel *lbl_finish_restore_gpr = gen_new_label(); \
tcg_gen_brcond_tl(TCG_COND_EQ, first_pass, one, lbl_save_gpr); \
\
for (i = 0; i < CPU_NB_REGS; ++i) { \
\
gpr_sv = tcg_const_ptr(&persistent_saved_gpr[i]); \
tcg_gen_ld_tl(cpu_regs[i], gpr_sv, 0); \
\
} \
\
tcg_gen_br(lbl_finish_restore_gpr); \
\
gen_set_label(lbl_save_gpr); \
\
for (i = 0; i < CPU_NB_REGS; ++i) { \
\
gpr_sv = tcg_const_ptr(&persistent_saved_gpr[i]); \
tcg_gen_st_tl(cpu_regs[i], gpr_sv, 0); \
\
} \
\
gen_set_label(lbl_finish_restore_gpr); \
tcg_temp_free(first_pass); \
\
} else if (afl_persistent_ret_addr == 0) { \
\
TCGv_ptr stack_off_ptr = tcg_const_ptr(&persistent_stack_offset); \
TCGv stack_off = tcg_temp_new(); \
tcg_gen_ld_tl(stack_off, stack_off_ptr, 0); \
tcg_gen_sub_tl(cpu_regs[R_ESP], cpu_regs[R_ESP], stack_off); \
tcg_temp_free(stack_off); \
\
} \
\
} while (0)
#define AFL_QEMU_TARGET_i386_SNIPPET \
if (is_persistent) { \
\
if (s->pc == afl_persistent_addr) { \
\
I386_RESTORE_STATE_FOR_PERSISTENT; \
/*tcg_gen_afl_call0(log_x86_saved_gpr); \
tcg_gen_afl_call0(log_x86_sp_content);*/ \
\
if (afl_persistent_ret_addr == 0) { \
\
TCGv_ptr paddr = tcg_const_ptr(afl_persistent_addr); \
tcg_gen_st_tl(paddr, cpu_regs[R_ESP], persisent_retaddr_offset); \
\
} \
tcg_gen_afl_call0(&afl_persistent_loop); \
/*tcg_gen_afl_call0(log_x86_sp_content);*/ \
\
} else if (afl_persistent_ret_addr && s->pc == afl_persistent_ret_addr) { \
\
gen_jmp_im(s, afl_persistent_addr); \
gen_eob(s); \
\
} \
\
}
|
