kernel/fiasco/src/kern/ia32/32/thread-dbf.cpp

   1 INTERFACE:
   2
   3 EXTENSION class Thread
   4 {
   5 private:
   6   static void handle_double_fault (void) asm ("thread_handle_double_fault");
   7
   8 public:
   9   static bool may_enter_jdb;
  10 };
  11
  12
  13 IMPLEMENTATION:
  14
  15 #include <cstdio>
  16 #include "cpu.h"
  17 #include "kernel_console.h"
  18 #include "processor.h"
  19 #include "reset.h"
  20 #include "trap_state.h"
  21 #include "tss.h"
  22 #include "watchdog.h"
  23
  24
  25 bool Thread::may_enter_jdb = false;
  26
  27 IMPLEMENT
  28 void
  29 Thread::handle_double_fault (void)
  30 {
  31   // cannot use current_cpu() here because this must run on a thread stack,
  32   // not on a dbf stack
  33   volatile Tss *tss = Cpu::boot_cpu()->get_tss();
  34   int c;
  35
  36   Watchdog::disable();
  37
  38   printf ("\n"
  39           "\033[1;31mDOUBLE FAULT!\033[m\n"
  40           "EAX=%08x  ESI=%08x  DS=%04x  \n"
  41           "EBX=%08x  EDI=%08x  ES=%04x\n"
  42           "ECX=%08x  EBP=%08x  GS=%04x\n"
  43           "EDX=%08x  ESP=%08x  SS=%04x   ESP0=%08lx\n"
  44           "EFL=%08x  EIP=%08x  CS=%04x    CPU=%u\n",
  45           tss->_eax,    tss->_esi, tss->_ds & 0xffff,
  46           tss->_ebx,    tss->_edi, tss->_es & 0xffff,
  47           tss->_ecx,    tss->_ebp, tss->_gs & 0xffff,
  48           tss->_edx,    tss->_esp, tss->_ss & 0xffff, tss->_esp0,
  49           tss->_eflags, tss->_eip, tss->_cs & 0xffff,
  50           cxx::int_value<Cpu_number>(current_cpu()));
  51
  52   if (may_enter_jdb)
  53     {
  54       puts ("Return reboots, \"k\" tries to enter the L4 kernel debugger...");
  55
  56       while ((c = Kconsole::console()->getchar(false)) == -1)
  57         Proc::pause();
  58
  59       if (c == 'k' || c == 'K')
  60         {
  61           Mword dummy;
  62           Trap_state ts;
  63
  64           // built a nice trap state the jdb can work with
  65           ts._ax    = tss->_eax;
  66           ts._bx    = tss->_ebx;
  67           ts._cx    = tss->_ecx;
  68           ts._dx    = tss->_edx;
  69           ts._si    = tss->_esi;
  70           ts._di    = tss->_edi;
  71           ts._bp    = tss->_ebp;
  72           ts.sp(tss->_esp);
  73           ts.cs(tss->_cs);
  74           ts._ds     = tss->_ds;
  75           ts._es     = tss->_es;
  76           ts.ss(tss->_ss);
  77           ts._fs     = tss->_fs;
  78           ts._gs     = tss->_gs;
  79           ts._trapno = 8;
  80           ts._err    = 0;
  81           ts.ip(tss->_eip);
  82           ts.flags(tss->_eflags);
  83
  84           asm volatile
  85             (
  86              "call   *%2        \n\t"
  87              : "=a"(dummy)
  88              : "a"(&ts), "m"(nested_trap_handler)
  89              : "ecx", "edx", "memory");
  90         }
  91     }
  92   else
  93     {
  94       puts ("Return reboots");
  95       while ((Kconsole::console()->getchar(false)) == -1)
  96         Proc::pause();
  97     }
  98
  99   puts ("\033[1mRebooting...\033[0m");
 100   platform_reset();
 101 }