tracechild.cc revision 8229
13115SN/A/* 24125SN/A * Copyright (c) 2006-2007 The Regents of The University of Michigan 33115SN/A * All rights reserved. 43115SN/A * 53115SN/A * Redistribution and use in source and binary forms, with or without 63115SN/A * modification, are permitted provided that the following conditions are 73115SN/A * met: redistributions of source code must retain the above copyright 83115SN/A * notice, this list of conditions and the following disclaimer; 93115SN/A * redistributions in binary form must reproduce the above copyright 103115SN/A * notice, this list of conditions and the following disclaimer in the 113115SN/A * documentation and/or other materials provided with the distribution; 123115SN/A * neither the name of the copyright holders nor the names of its 133115SN/A * contributors may be used to endorse or promote products derived from 143115SN/A * this software without specific prior written permission. 153115SN/A * 163115SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 173115SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 183115SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 193115SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 203115SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 213115SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 223115SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 233115SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 243115SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 253115SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 263115SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 273115SN/A * 283115SN/A * Authors: Gabe Black 293115SN/A */ 303115SN/A 316406SN/A#include <sys/ptrace.h> 323115SN/A#include <sys/wait.h> 333115SN/A 348229Snate@binkert.org#include <cerrno> 358229Snate@binkert.org#include <cstring> 368229Snate@binkert.org#include <iostream> 378229Snate@binkert.org 388229Snate@binkert.org#include "tracechild.hh" 398229Snate@binkert.org 403115SN/Ausing namespace std; 413115SN/A 428108SN/Abool 438108SN/ATraceChild::startTracing(const char * pathToFile, char * const argv[]) 443115SN/A{ 458108SN/A instructions = 0; 468108SN/A pid = fork(); 478108SN/A if (pid == -1) { 488108SN/A cout << "fork failed" << endl; 498108SN/A return false; 508108SN/A } else if (pid == 0) { 518108SN/A //We're the child. Get things ready and then exec the program to trace. 528108SN/A //Let our parent trace us 538108SN/A if (ptrace(PTRACE_TRACEME, 0, 0, 0) == -1) { 548108SN/A cout << "Failure calling TRACEME\n" << strerror(errno) << endl; 558108SN/A return false; 563115SN/A } 573115SN/A 588108SN/A //Set up an empty environment for the child... We would want to 598108SN/A //specify this somehow at some point 608108SN/A char * env[] = {NULL}; 618108SN/A 628108SN/A //Start the program to trace 638108SN/A execve(pathToFile, argv, env); 648108SN/A 658108SN/A //We should never get here, so this is an error! 668108SN/A cout << "Exec failed\n" << strerror(errno) << endl; 678108SN/A return false; 688108SN/A } 698108SN/A 708108SN/A //From this point forward, we know we're in the parent process. 718108SN/A if (!doWait()) { 728108SN/A cout << "Didn't wait successfully" << endl; 738108SN/A return false; 748108SN/A } 758108SN/A tracing = true; 768108SN/A return true; 773115SN/A} 783115SN/A 798108SN/Abool 808108SN/ATraceChild::stopTracing() 813115SN/A{ 828108SN/A if (ptrace(PTRACE_KILL, pid, 0, 0) != 0) 838108SN/A return false; 848108SN/A tracing = false; 858108SN/A return true; 863115SN/A} 873115SN/A 888108SN/Abool 898108SN/ATraceChild::step() 903115SN/A{ 918108SN/A ptraceSingleStep(); 923115SN/A} 933115SN/A 948108SN/Abool 958108SN/ATraceChild::ptraceSingleStep() 963115SN/A{ 978108SN/A if (!tracing) { 988108SN/A cout << "Not tracing!" << endl; 998108SN/A return false; 1008108SN/A } 1018108SN/A if (ptrace(PTRACE_SINGLESTEP, pid, 0, 0) != 0) { 1028108SN/A switch (errno) { 1038108SN/A case EBUSY: cout << "EBUSY" << endl; break; 1048108SN/A case EFAULT: cout << "EFAULT" << endl; break; 1058108SN/A case EIO: cout << "EIO" << endl; break; 1068108SN/A case EPERM: cout << "EPERM" << endl; break; 1078108SN/A case ESRCH: cout << "ESRCH" << endl; break; 1088108SN/A default: cout << "Unknown error" << endl; break; 1093115SN/A } 1108108SN/A cout << "Not able to single step!" << endl; 1118108SN/A tracing == false; 1128108SN/A return false; 1138108SN/A } 1148108SN/A doWait(); 1158108SN/A update(pid); 1163115SN/A} 1173115SN/A 1188108SN/Abool 1198108SN/ATraceChild::doWait() 1203115SN/A{ 1218108SN/A int wait_val; 1228108SN/A wait(&wait_val); 1238108SN/A if (WIFEXITED(wait_val)) { 1248108SN/A cerr << "Program exited! Exit status is " 1258108SN/A << WEXITSTATUS(wait_val) << endl; 1268108SN/A cerr << "Executed " << instructions 1278108SN/A << " instructions." << endl; 1288108SN/A tracing = false; 1298108SN/A return false; 1308108SN/A } 1318108SN/A if (WIFSIGNALED(wait_val)) { 1328108SN/A if (WTERMSIG(wait_val)) 1338108SN/A cerr << "Program terminated by signal " 1348108SN/A << WTERMSIG(wait_val) << endl; 1358108SN/A if (WCOREDUMP(wait_val)) 1368108SN/A cerr << "Program core dumped!" << endl; 1378108SN/A tracing = false; 1388108SN/A cerr << "Executed " << instructions 1398108SN/A << " instructions." << endl; 1408108SN/A return false; 1418108SN/A } 1428108SN/A if (WIFSTOPPED(wait_val) && WSTOPSIG(wait_val) != SIGTRAP) { 1438108SN/A cerr << "Program stopped by signal " << WSTOPSIG(wait_val) << endl; 1448108SN/A tracing = false; 1458108SN/A cerr << "Executed " << instructions << " instructions." << endl; 1468108SN/A return false; 1478108SN/A } 1488108SN/A return true; 1493115SN/A} 150