l4/pkg/plr/server/src/fault_handlers/trap_observer.cc

   1 /*
   2  * trap_observer.cc --
   3  *
   4  *     Implementation of the observer handling all traps, e.g.,
   5  *     system calls. Also, this observer handles Fiasco JDB
   6  *     traps.
   7  *
   8  * (c) 2011-2013 Björn Döbel <doebel@os.inf.tu-dresden.de>,
   9  *     economic rights: Technische Universität Dresden (Germany)
  10  * This file is part of TUD:OS and distributed under the terms of the
  11  * GNU General Public License 2.
  12  * Please see the COPYING-GPL-2 file for details.
  13  */
  14
  15 #include "../app_loading"
  16 #include "observers.h"
  17
  18 char const * const Romain::TrapObserver::jdb_out_prefix = "\033[32;1m";
  19 char const * const Romain::TrapObserver::jdb_out_suffix = "\033[0m";
  20
  21 DEFINE_EMPTY_STARTUP(TrapObserver)
  22
  23 void Romain::TrapObserver::status() const { }
  24
  25 Romain::Observer::ObserverReturnVal
  26 Romain::TrapObserver::notify(Romain::App_instance *inst,
  27                              Romain::App_thread *t,
  28                              Romain::Thread_group *tg,
  29                              Romain::App_model *a)
  30 {
  31         if (t->vcpu()->r()->trapno == 6) {
  32                 ERROR() << "Invalid opcode @ " << std::hex << t->vcpu()->r()->ip;
  33                 enter_kdebug("invalid opcode");
  34         }
  35
  36         if (!entry_reason_is_int3(t->vcpu(), inst, a)) {
  37                 return Romain::Observer::Ignored;
  38         }
  39
  40         // address is already 1 _behind_ the INT3 opcode
  41         l4_addr_t local = a->rm()->remote_to_local(t->vcpu()->r()->ip, inst->id());
  42         unsigned op = *(unsigned char*)local;
  43
  44         switch(op) {
  45                 case 0xEB: // jmp -> enter_kdebug(text)
  46                         {
  47                                 unsigned len = *(unsigned char*)(local+1);
  48                                 char strbuf[len+1];
  49                                 memcpy(strbuf, (unsigned char*)local+2, len);
  50                                 strbuf[len] = 0;
  51                                 INFO() << TrapObserver::jdb_out_prefix << "JDB:" << TrapObserver::jdb_out_suffix << " " << strbuf;
  52                                 enter_kdebug("enter_kdebug issued");
  53
  54 #if 0
  55                                 DEBUG() << std::hex << t->vcpu()->r()->ip;
  56                                 t->vcpu()->r()->ip += len;
  57                                 t->vcpu()->r()->ip += 2;
  58                                 DEBUG() << std::hex << t->vcpu()->r()->ip;
  59 #endif
  60                                 //t->vcpu()->r()->ip -= 1;
  61                         }
  62                         break;
  63                 case 0x3C: // outhex() & co.
  64                         {
  65                                 unsigned char out_op = *(unsigned char*)(local+1);
  66                                 switch(out_op) {
  67                                         case 0: // outchar
  68                                                 INFO() << TrapObserver::jdb_out_prefix << "JDB:" << TrapObserver::jdb_out_suffix << " " << (char)(t->vcpu()->r()->ax & 0xFF);
  69                                                 break;
  70                                         case 2: // outstring
  71                                                 {
  72                                                         char buf[80];
  73                                                         snprintf(buf, 80, "%s", (char*)a->rm()->remote_to_local(t->vcpu()->r()->ax, inst->id()));
  74                                                         INFO() << TrapObserver::jdb_out_prefix << "JDB:" << TrapObserver::jdb_out_suffix << " " << buf;
  75                                                         if (buf[strlen(buf)-1] == '\n') {
  76                                                                 enter_kdebug("jdb newline");
  77                                                         }
  78                                                 }
  79                                                 break;
  80                                         case 5: // outhex32
  81                                                 INFO() << TrapObserver::jdb_out_prefix << "JDB:" << TrapObserver::jdb_out_suffix << " " << std::hex << t->vcpu()->r()->ax;
  82                                                 break;
  83                                         default:
  84                                                 ERROR() << "unhandled out op: " << std::hex << (int)out_op;
  85                                                 break;
  86                                 };
  87                         }
  88                         break;
  89                 default:
  90 #if 0
  91                         ERROR() << "Unhandled JDB opcode: 0x" << std::hex << op;
  92                         break;
  93 #else
  94                         return Romain::Observer::Ignored;
  95 #endif
  96         }
  97
  98         //enter_kdebug("int 3");
  99         return Romain::Observer::Replicatable;
 100 }