source/process.cpp

   1 /* $Id$
   2
   3 This file is part of gldbg
   4 Copyright © 2009, 2011  Mikko Rasa, Mikkosoft Productions
   5 Distributed under the GPL
   6 */
   7
   8 #include <stdexcept>
   9 #include <cstdlib>
  10 #include <cerrno>
  11 #include <cstring>
  12 #include <sys/ptrace.h>
  13 #include <sys/wait.h>
  14 #include "process.h"
  15 #include "strformat.h"
  16
  17 using namespace std;
  18
  19 Process::Process(const vector<string> &a):
  20         args(a),
  21         pid(-1),
  22         state(INACTIVE)
  23 { }
  24
  25 void Process::setenv(const string &key, const string &value)
  26 {
  27         env[key] = value;
  28 }
  29
  30 void Process::launch()
  31 {
  32         if(state!=INACTIVE)
  33                 throw logic_error("Program is already running");
  34
  35         pid = fork();
  36         if(pid==0)
  37         {
  38                 for(map<string, string>::const_iterator i=env.begin(); i!=env.end(); ++i)
  39                         ::setenv(i->first.c_str(), i->second.c_str(), true);
  40                 std::vector<char *> argv(args.size()+1);
  41                 for(unsigned i=0; i<args.size(); ++i)
  42                         argv[i] = strdup(args[i].c_str());
  43                 argv[args.size()] = 0;
  44                 ::ptrace(PTRACE_TRACEME, 0, 0, 0);
  45                 execvp(argv[0], &argv[0]);
  46                 ::exit(255);
  47         }
  48         else if(pid>0)
  49                 state = STARTING;
  50         else
  51                 throw runtime_error(strformat("Could not launch process: %s", strerror(errno)));
  52 }
  53
  54 int Process::check()
  55 {
  56         int status;
  57         int ret = waitpid(pid, &status, WNOHANG);
  58         if(ret==pid)
  59         {
  60                 if(WIFEXITED(status))
  61                 {
  62                         int code = WEXITSTATUS(status);
  63                         state = INACTIVE;
  64                         return 0x100|code;
  65                 }
  66                 else if(WIFSIGNALED(status))
  67                 {
  68                         state = INACTIVE;
  69                         return 0x200|WTERMSIG(status);
  70                 }
  71                 else if(WIFSTOPPED(status))
  72                 {
  73                         int sig = WSTOPSIG(status);
  74                         if(sig==SIGTRAP && state==STARTING)
  75                         {
  76                                 ptrace(PTRACE_CONT, 0, 0);
  77                                 state = RUNNING;
  78                         }
  79                         else
  80                         {
  81                                 state = STOPPED;
  82                                 return 0x300|sig;
  83                         }
  84                 }
  85         }
  86
  87         return 0;
  88 }
  89
  90 void Process::resume(int sig)
  91 {
  92         if(state!=STOPPED)
  93                 throw logic_error("Program is not stopped");
  94         ptrace(PTRACE_CONT, 0, (void *)sig);
  95         state = RUNNING;
  96 }
  97
  98 void Process::kill()
  99 {
 100         if(state==INACTIVE)
 101                 throw logic_error("Program is not running");
 102         ptrace(PTRACE_KILL, 0, 0);
 103         // Make the debugger wait() for us
 104         state = RUNNING;
 105 }
 106
 107 long Process::ptrace(int req, void *addr, void *data)
 108 {
 109         int ret = ::ptrace((__ptrace_request)req, pid, addr, data);
 110         if(ret==-1 && ((req!=PTRACE_PEEKTEXT && req!=PTRACE_PEEKDATA && req!=PTRACE_PEEKUSER) || errno))
 111                 throw runtime_error(strformat("ptrace error: %s", strerror(errno)));
 112         return ret;
 113 }