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/*
* Copyright (c) 2006 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, const char * arg)
{
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
execl(pathToFile, arg);
//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;
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;
return false;
}
if(WIFSTOPPED(wait_val) && WSTOPSIG(wait_val) != SIGTRAP)
{
cerr << "Program stopped by signal "
<< WSTOPSIG(wait_val) << endl;
tracing = false;
return false;
}
return true;
}
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