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
|
/*
* Copyright (c) 2006-2007 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Gabe Black
*/
#include "tracechild.hh"
#include <sys/wait.h>
#include <sys/ptrace.h>
#include <iostream>
#include <errno.h>
using namespace std;
bool TraceChild::startTracing(const char * pathToFile, char * const argv[])
{
instructions = 0;
pid = fork();
if(pid == -1)
{
cout << "fork failed" << endl;
return false;
}
else if(pid == 0)
{
//We're the child. Get things ready and then exec the
//program to trace.
//Let our parent trace us
ptrace(PTRACE_TRACEME, 0, 0, 0);
//Start the program to trace
execv(pathToFile, argv);
//We should never get here, so this is an error!
return false;
}
//From this point forward, we know we're in the parent process.
if(!doWait())
{
cout << "Didn't wait successfully" << endl;
return false;
}
tracing = true;
if(!update(pid))
{
cout << "Didn't update successfully!" << endl;
return false;
}
return true;
}
bool TraceChild::stopTracing()
{
if(ptrace(PTRACE_KILL, pid, 0, 0) != 0)
return false;
tracing = false;
return true;
}
bool TraceChild::step()
{
ptraceSingleStep();
}
bool TraceChild::ptraceSingleStep()
{
if(!tracing)
{
cout << "Not tracing!" << endl;
return false;
}
if(ptrace(PTRACE_SINGLESTEP, pid, 0, 0) != 0)
{
switch(errno)
{
case EBUSY: cout << "EBUSY" << endl; break;
case EFAULT: cout << "EFAULT" << endl; break;
case EIO: cout << "EIO" << endl; break;
case EPERM: cout << "EPERM" << endl; break;
case ESRCH: cout << "ESRCH" << endl; break;
default: cout << "Unknown error" << endl; break;
}
cout << "Not able to single step!" << endl;
tracing == false;
return false;
}
doWait();
update(pid);
}
bool TraceChild::doWait()
{
int wait_val;
wait(&wait_val);
if(WIFEXITED(wait_val))
{
cerr << "Program exited! Exit status is "
<< WEXITSTATUS(wait_val) << endl;
cerr << "Executed " << instructions
<< " instructions." << endl;
tracing = false;
return false;
}
if(WIFSIGNALED(wait_val))
{
if(WTERMSIG(wait_val))
cerr << "Program terminated by signal "
<< WTERMSIG(wait_val) << endl;
if(WCOREDUMP(wait_val))
cerr << "Program core dumped!" << endl;
tracing = false;
cerr << "Executed " << instructions
<< " instructions." << endl;
return false;
}
if(WIFSTOPPED(wait_val) && WSTOPSIG(wait_val) != SIGTRAP)
{
cerr << "Program stopped by signal "
<< WSTOPSIG(wait_val) << endl;
tracing = false;
cerr << "Executed " << instructions
<< " instructions." << endl;
return false;
}
return true;
}
|
