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
|
#include "frida-gum.h"
#include "debug.h"
#include "instrument.h"
#include "util.h"
#if defined(__i386__)
static GumAddress current_log_impl = GUM_ADDRESS(0);
static void instrument_coverage_function(GumX86Writer *cw) {
gum_x86_writer_put_pushfx(cw);
gum_x86_writer_put_push_reg(cw, GUM_REG_ECX);
gum_x86_writer_put_push_reg(cw, GUM_REG_EDX);
gum_x86_writer_put_mov_reg_address(cw, GUM_REG_ECX,
GUM_ADDRESS(&previous_pc));
gum_x86_writer_put_mov_reg_reg_ptr(cw, GUM_REG_EDX, GUM_REG_ECX);
gum_x86_writer_put_xor_reg_reg(cw, GUM_REG_EDX, GUM_REG_EDI);
gum_x86_writer_put_add_reg_imm(cw, GUM_REG_EDX, GUM_ADDRESS(__afl_area_ptr));
/* add byte ptr [edx], 1 */
uint8_t add_byte_ptr_edx_1[] = {0x80, 0x02, 0x01};
gum_x86_writer_put_bytes(cw, add_byte_ptr_edx_1, sizeof(add_byte_ptr_edx_1));
/* adc byte ptr [edx], 0 */
uint8_t adc_byte_ptr_edx_0[] = {0x80, 0x12, 0x00};
gum_x86_writer_put_bytes(cw, adc_byte_ptr_edx_0, sizeof(adc_byte_ptr_edx_0));
gum_x86_writer_put_shr_reg_u8(cw, GUM_REG_EDI, 1);
gum_x86_writer_put_mov_reg_ptr_reg(cw, GUM_REG_ECX, GUM_REG_EDI);
gum_x86_writer_put_pop_reg(cw, GUM_REG_EDX);
gum_x86_writer_put_pop_reg(cw, GUM_REG_ECX);
gum_x86_writer_put_popfx(cw);
gum_x86_writer_put_ret(cw);
}
gboolean instrument_is_coverage_optimize_supported(void) {
return true;
}
void instrument_coverage_optimize(const cs_insn * instr,
GumStalkerOutput *output) {
UNUSED_PARAMETER(instr);
UNUSED_PARAMETER(output);
guint64 current_pc = instr->address;
guint64 area_offset = (current_pc >> 4) ^ (current_pc << 8);
area_offset &= MAP_SIZE - 1;
GumX86Writer *cw = output->writer.x86;
if (current_log_impl == 0 ||
!gum_x86_writer_can_branch_directly_between(cw->pc, current_log_impl) ||
!gum_x86_writer_can_branch_directly_between(cw->pc + 128,
current_log_impl)) {
gconstpointer after_log_impl = cw->code + 1;
gum_x86_writer_put_jmp_near_label(cw, after_log_impl);
current_log_impl = cw->pc;
instrument_coverage_function(cw);
gum_x86_writer_put_label(cw, after_log_impl);
}
// gum_x86_writer_put_breakpoint(cw);
gum_x86_writer_put_push_reg(cw, GUM_REG_EDI);
gum_x86_writer_put_mov_reg_address(cw, GUM_REG_EDI, area_offset);
gum_x86_writer_put_call_address(cw, current_log_impl);
gum_x86_writer_put_pop_reg(cw, GUM_REG_EDI);
}
#endif
|
