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 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::App_model *a)
  29 {
  30         if (t->vcpu()->r()->trapno == 6) {
  31                 enter_kdebug("invalid opcode");
  32         }
  33
  34         if (!entry_reason_is_int3(t->vcpu(), inst, a)) {
  35                 return Romain::Observer::Ignored;
  36         }
  37
  38         // address is already 1 _behind_ the INT3 opcode
  39         l4_addr_t local = a->rm()->remote_to_local(t->vcpu()->r()->ip, inst->id());
  40         unsigned op = *(unsigned char*)local;
  41
  42         switch(op) {
  43                 case 0xEB: // jmp -> enter_kdebug(text)
  44                         {
  45                                 unsigned len = *(unsigned char*)(local+1);
  46                                 char strbuf[len+1];
  47                                 memcpy(strbuf, (unsigned char*)local+2, len);
  48                                 strbuf[len] = 0;
  49                                 INFO() << TrapObserver::jdb_out_prefix << "JDB:" << TrapObserver::jdb_out_suffix << " " << strbuf;
  50                                 enter_kdebug("enter_kdebug issued");
  51
  52 #if 0
  53                                 DEBUG() << std::hex << t->vcpu()->r()->ip;
  54                                 t->vcpu()->r()->ip += len;
  55                                 t->vcpu()->r()->ip += 2;
  56                                 DEBUG() << std::hex << t->vcpu()->r()->ip;
  57 #endif
  58                                 //t->vcpu()->r()->ip -= 1;
  59                         }
  60                         break;
  61                 case 0x3C: // outhex() & co.
  62                         {
  63                                 unsigned char out_op = *(unsigned char*)(local+1);
  64                                 switch(out_op) {
  65                                         case 0: // outchar
  66                                                 INFO() << TrapObserver::jdb_out_prefix << "JDB:" << TrapObserver::jdb_out_suffix << " " << (char)(t->vcpu()->r()->ax & 0xFF);
  67                                                 break;
  68                                         case 2: // outstring
  69                                                 {
  70                                                         char buf[80];
  71                                                         snprintf(buf, 80, "%s", (char*)a->rm()->remote_to_local(t->vcpu()->r()->ax, inst->id()));
  72                                                         INFO() << TrapObserver::jdb_out_prefix << "JDB:" << TrapObserver::jdb_out_suffix << " " << buf;
  73                                                         if (buf[strlen(buf)-1] == '\n') {
  74                                                                 enter_kdebug("jdb newline");
  75                                                         }
  76                                                 }
  77                                                 break;
  78                                         case 5: // outhex32
  79                                                 INFO() << TrapObserver::jdb_out_prefix << "JDB:" << TrapObserver::jdb_out_suffix << " " << std::hex << t->vcpu()->r()->ax;
  80                                                 break;
  81                                         default:
  82                                                 ERROR() << "unhandled out op: " << std::hex << (int)out_op;
  83                                                 break;
  84                                 };
  85                         }
  86                         break;
  87                 default:
  88 #if 0
  89                         ERROR() << "Unhandled JDB opcode: 0x" << std::hex << op;
  90                         break;
  91 #else
  92                         return Romain::Observer::Ignored;
  93 #endif
  94         }
  95
  96         //enter_kdebug("int 3");
  97         return Romain::Observer::Replicatable;
  98 }