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 <unistd.h>
  13 #include <sys/ptrace.h>
  14 #include <sys/wait.h>
  15 #include "process.h"
  16 #include "strformat.h"
  17
  18 using namespace std;
  19
  20 Process::Process(const vector<string> &a):
  21         args(a),
  22         pid(-1),
  23         state(INACTIVE)
  24 { }
  25
  26 void Process::setenv(const string &key, const string &value)
  27 {
  28         env[key] = value;
  29 }
  30
  31 void Process::launch()
  32 {
  33         if(state!=INACTIVE)
  34                 throw logic_error("Program is already running");
  35
  36         pid = fork();
  37         if(pid==0)
  38         {
  39                 for(map<string, string>::const_iterator i=env.begin(); i!=env.end(); ++i)
  40                         ::setenv(i->first.c_str(), i->second.c_str(), true);
  41                 std::vector<char *> argv(args.size()+1);
  42                 for(unsigned i=0; i<args.size(); ++i)
  43                         argv[i] = strdup(args[i].c_str());
  44                 argv[args.size()] = 0;
  45                 ::ptrace(PTRACE_TRACEME, 0, 0, 0);
  46                 execvp(argv[0], &argv[0]);
  47                 ::exit(255);
  48         }
  49         else if(pid>0)
  50                 state = STARTING;
  51         else
  52                 throw runtime_error(strformat("Could not launch process: %s", strerror(errno)));
  53 }
  54
  55 int Process::check()
  56 {
  57         int status;
  58         int ret = waitpid(pid, &status, WNOHANG);
  59         if(ret==pid)
  60         {
  61                 if(WIFEXITED(status))
  62                 {
  63                         int code = WEXITSTATUS(status);
  64                         state = INACTIVE;
  65                         return 0x100|code;
  66                 }
  67                 else if(WIFSIGNALED(status))
  68                 {
  69                         state = INACTIVE;
  70                         return 0x200|WTERMSIG(status);
  71                 }
  72                 else if(WIFSTOPPED(status))
  73                 {
  74                         int sig = WSTOPSIG(status);
  75                         if(sig==SIGTRAP && state==STARTING)
  76                         {
  77                                 ptrace(PTRACE_CONT, 0, 0);
  78                                 state = RUNNING;
  79                         }
  80                         else
  81                         {
  82                                 state = STOPPED;
  83                                 return 0x300|sig;
  84                         }
  85                 }
  86         }
  87
  88         return 0;
  89 }
  90
  91 void Process::resume(int sig)
  92 {
  93         if(state!=STOPPED)
  94                 throw logic_error("Program is not stopped");
  95         ptrace(PTRACE_CONT, 0, (void *)sig);
  96         state = RUNNING;
  97 }
  98
  99 void Process::kill()
 100 {
 101         if(state==INACTIVE)
 102                 throw logic_error("Program is not running");
 103         ptrace(PTRACE_KILL, 0, 0);
 104         // Make the debugger wait() for us
 105         state = RUNNING;
 106 }
 107
 108 long Process::ptrace(int req, void *addr, void *data)
 109 {
 110         int ret = ::ptrace((__ptrace_request)req, pid, addr, data);
 111         if(ret==-1 && ((req!=PTRACE_PEEKTEXT && req!=PTRACE_PEEKDATA && req!=PTRACE_PEEKUSER) || errno))
 112                 throw runtime_error(strformat("ptrace error: %s", strerror(errno)));
 113         return ret;
 114 }