blob: 81e99e6eadf0edd27e5b7cb8565c0b81bbf088c1 (
plain) (
blame)
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
|
//:: call
:(before "End Initialize Op Names")
put_new(Name, "e8", "call disp32 (call)");
:(code)
void test_call_disp32() {
Mem.push_back(vma(0xbd000000)); // manually allocate memory
Reg[ESP].u = 0xbd000064;
run(
"== code 0x1\n"
// op ModR/M SIB displacement immediate
" e8 a0 00 00 00 \n" // call function offset at 0x000000a0
// next EIP is 6
);
CHECK_TRACE_CONTENTS(
"run: call imm32 0x000000a0\n"
"run: decrementing ESP to 0xbd000060\n"
"run: pushing value 0x00000006\n"
"run: jumping to 0x000000a6\n"
);
}
:(before "End Single-Byte Opcodes")
case 0xe8: { // call disp32 relative to next EIP
const int32_t offset = next32();
++Callstack_depth;
trace(Callstack_depth+1, "run") << "call imm32 0x" << HEXWORD << offset << end();
//? cerr << "push: EIP: " << EIP << " => " << Reg[ESP].u << '\n';
push(EIP);
EIP += offset;
trace(Callstack_depth+1, "run") << "jumping to 0x" << HEXWORD << EIP << end();
break;
}
//:
:(code)
void test_call_r32() {
Mem.push_back(vma(0xbd000000)); // manually allocate memory
Reg[ESP].u = 0xbd000064;
Reg[EBX].u = 0x000000a0;
run(
"== code 0x1\n"
// op ModR/M SIB displacement immediate
" ff d3 \n" // call function offset at EBX
// next EIP is 3
);
CHECK_TRACE_CONTENTS(
"run: call to r/m32\n"
"run: r/m32 is EBX\n"
"run: decrementing ESP to 0xbd000060\n"
"run: pushing value 0x00000003\n"
"run: jumping to 0x000000a3\n"
);
}
:(before "End Op ff Subops")
case 2: { // call function pointer at r/m32
trace(Callstack_depth+1, "run") << "call to r/m32" << end();
const int32_t* offset = effective_address(modrm);
push(EIP);
EIP += *offset;
trace(Callstack_depth+1, "run") << "jumping to 0x" << HEXWORD << EIP << end();
++Callstack_depth;
break;
}
:(code)
void test_call_mem_at_r32() {
Mem.push_back(vma(0xbd000000)); // manually allocate memory
Reg[ESP].u = 0xbd000064;
Reg[EBX].u = 0x2000;
run(
"== code 0x1\n"
// op ModR/M SIB displacement immediate
" ff 13 \n" // call function offset at *EBX
// next EIP is 3
"== data 0x2000\n"
"a0 00 00 00\n" // 0x000000a0
);
CHECK_TRACE_CONTENTS(
"run: call to r/m32\n"
"run: effective address is 0x00002000 (EBX)\n"
"run: decrementing ESP to 0xbd000060\n"
"run: pushing value 0x00000003\n"
"run: jumping to 0x000000a3\n"
);
}
//:: ret
:(before "End Initialize Op Names")
put_new(Name, "c3", "return from most recent unfinished call (ret)");
:(code)
void test_ret() {
Mem.push_back(vma(0xbd000000)); // manually allocate memory
Reg[ESP].u = 0xbd000064;
write_mem_u32(Reg[ESP].u, 0x10);
run(
"== code 0x1\n"
// op ModR/M SIB displacement immediate
" c3 \n" // return
"== data 0x2000\n"
"10 00 00 00\n" // 0x00000010
);
CHECK_TRACE_CONTENTS(
"run: return\n"
"run: popping value 0x00000010\n"
"run: jumping to 0x00000010\n"
);
}
:(before "End Single-Byte Opcodes")
case 0xc3: { // return from a call
trace(Callstack_depth+1, "run") << "return" << end();
--Callstack_depth;
EIP = pop();
trace(Callstack_depth+1, "run") << "jumping to 0x" << HEXWORD << EIP << end();
break;
}
|