tracechild.cc revision 8108 
1/*
2 * Copyright (c) 2006 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Gabe Black
29 */
30
31#include <iostream>
32#include <errno.h>
33#include <sys/ptrace.h>
34#include <stdint.h>
35
36#include "tracechild_i386.hh"
37
38using namespace std;
39
40char * I386TraceChild::regNames[numregs] = {
41    //GPRs
42    "eax", "ebx", "ecx", "edx",
43    //Index registers
44    "esi", "edi",
45    //Base pointer and stack pointer
46    "ebp", "esp",
47    //Segmentation registers
48    "cs", "ds", "es", "fs", "gs", "ss",
49    //PC
50    "eip"};
51
52int64_t
53I386TraceChild::getRegs(user_regs_struct & myregs, int num)
54{
55    assert(num < numregs && num >= 0);
56    switch (num) {
57      //GPRs
58      case EAX: return myregs.eax;
59      case EBX: return myregs.ebx;
60      case ECX: return myregs.ecx;
61      case EDX: return myregs.edx;
62      //Index registers
63      case ESI: return myregs.esi;
64      case EDI: return myregs.edi;
65      //Base pointer and stack pointer
66      case EBP: return myregs.ebp;
67      case ESP: return myregs.esp;
68      //Segmentation registers
69      case CS: return myregs.cs;
70      case DS: return myregs.ds;
71      case ES: return myregs.es;
72      case FS: return myregs.fs;
73      case GS: return myregs.gs;
74      case SS: return myregs.ss;
75      //PC
76      case EIP: return myregs.eip;
77      default:
78        assert(0);
79        return 0;
80    }
81}
82
83bool
84I386TraceChild::update(int pid)
85{
86    oldregs = regs;
87    if (ptrace(PTRACE_GETREGS, pid, 0, &regs) != 0)
88        return false;
89    for (unsigned int x = 0; x < numregs; x++) {
90        regDiffSinceUpdate[x] = (getRegVal(x) != getOldRegVal(x));
91    }
92}
93
94I386TraceChild::I386TraceChild()
95{
96    for (unsigned int x = 0; x < numregs; x++)
97        regDiffSinceUpdate[x] = false;
98}
99
100int64_t
101I386TraceChild::getRegVal(int num)
102{
103    return getRegs(regs, num);
104}
105
106int64_t
107I386TraceChild::getOldRegVal(int num)
108{
109    return getRegs(oldregs, num);
110}
111
112char *
113I386TraceChild::printReg(int num)
114{
115    sprintf(printBuffer, "0x%08X", getRegVal(num));
116    return printBuffer;
117}
118
119TraceChild *
120genTraceChild()
121{
122    return new I386TraceChild;
123}
124