kernel/fiasco/src/kern/arm/thread-jdb.cpp

   1 INTERFACE [arm-debug]:
   2
   3 #include "trap_state.h"
   4
   5 EXTENSION class Thread
   6 {
   7 public:
   8   typedef void (*Dbg_extension_entry)(Thread *t, Entry_frame *r);
   9   static Dbg_extension_entry dbg_extension[64];
  10
  11 protected:
  12   static int call_nested_trap_handler(Trap_state *ts) asm ("call_nested_trap_handler");
  13   static Trap_state::Handler nested_trap_handler FIASCO_FASTCALL;
  14 };
  15
  16
  17 //-----------------------------------------------------------------------------
  18 IMPLEMENTATION [arm && debug]:
  19
  20 #include "kernel_task.h"
  21 #include "mem_layout.h"
  22 #include "mmu.h"
  23
  24 #include <cstring>
  25
  26 Thread::Dbg_extension_entry Thread::dbg_extension[64];
  27
  28 Trap_state::Handler Thread::nested_trap_handler FIASCO_FASTCALL;
  29
  30 extern "C" void sys_kdb_ke()
  31 {
  32   cpu_lock.lock();
  33   Thread *t = current_thread();
  34   Unsigned32 x = Thread::peek_user((Unsigned32 *)t->regs()->ip(), t);
  35
  36   if (EXPECT_FALSE(t->is_kernel_mem_op_hit_and_clear()))
  37     x = 0;
  38
  39   if ((x & 0xffff0000) == 0xe35e0000)
  40     {
  41       unsigned func = x & 0x3f;
  42       if (Thread::dbg_extension[func])
  43         {
  44           Thread::dbg_extension[func](t, t->regs());
  45           t->regs()->ip(t->regs()->ip() + 4);
  46           return;
  47         }
  48     }
  49
  50   char str[32] = "USER ENTRY";
  51   if ((x & 0xfffffff0) == 0xea000000)
  52     // check for always branch, no return, maximum 32 bytes forward
  53     {
  54       char const *user_str = reinterpret_cast<char const *>(t->regs()->ip() + 4);
  55       for (unsigned i = 0; i < sizeof(str); ++i)
  56         {
  57           str[i] = Thread::peek_user(user_str + i, t);
  58           if (EXPECT_FALSE(t->is_kernel_mem_op_hit_and_clear()))
  59             {
  60               str[0] = 0;
  61               break;
  62             }
  63           if (str[i] == 0)
  64             break;
  65         }
  66
  67       str[sizeof(str)-1] = 0;
  68     }
  69
  70   kdb_ke(str);
  71 }
  72
  73 IMPLEMENT
  74 int
  75 Thread::call_nested_trap_handler(Trap_state *ts)
  76 {
  77   Cpu_phys_id phys_cpu = Proc::cpu_id();
  78   Cpu_number log_cpu = Cpu::cpus.find_cpu(Cpu::By_phys_id(phys_cpu));
  79   if (log_cpu == Cpu_number::nil())
  80     {
  81       printf("Trap on unknown CPU phys_id=%x\n",
  82              cxx::int_value<Cpu_phys_id>(phys_cpu));
  83       log_cpu = Cpu_number::boot_cpu();
  84     }
  85
  86   unsigned long &ntr = nested_trap_recover.cpu(log_cpu);
  87
  88   void *stack = 0;
  89
  90   if (!ntr)
  91     stack = dbg_stack.cpu(log_cpu).stack_top;
  92
  93   Mem_space *m = Mem_space::current_mem_space(log_cpu);
  94
  95   if (Kernel_task::kernel_task() != m)
  96     Kernel_task::kernel_task()->make_current();
  97
  98   Mword dummy1, tmp, ret;
  99   {
 100     register Mword _ts asm("r0") = (Mword)ts;
 101     register Cpu_number _lcpu asm("r1") = log_cpu;
 102
 103     asm volatile(
 104         "mov    %[origstack], sp         \n"
 105         "ldr    %[tmp], [%[ntr]]         \n"
 106         "teq    %[tmp], #0               \n"
 107         "moveq  sp, %[stack]             \n"
 108         "add    %[tmp], %[tmp], #1       \n"
 109         "str    %[tmp], [%[ntr]]         \n"
 110         "str    %[origstack], [sp, #-4]! \n"
 111         "str    %[ntr], [sp, #-4]!       \n"
 112         "adr    lr, 1f                   \n"
 113         "mov    pc, %[handler]           \n"
 114         "1:                              \n"
 115         "ldr    %[ntr], [sp], #4         \n"
 116         "ldr    sp, [sp]                 \n"
 117         "ldr    %[tmp], [%[ntr]]         \n"
 118         "sub    %[tmp], %[tmp], #1       \n"
 119         "str    %[tmp], [%[ntr]]         \n"
 120         : [origstack] "=&r" (dummy1), [tmp] "=&r" (tmp),
 121           "=r" (_ts), "=r" (_lcpu)
 122         : [ntr] "r" (&ntr), [stack] "r" (stack),
 123           [handler] "r" (*nested_trap_handler),
 124           "2" (_ts), "3" (_lcpu)
 125         : "memory", "r2", "r3", "r4");
 126
 127     ret = _ts;
 128   }
 129
 130   // the jdb-cpu might have changed things we shouldn't miss!
 131   Mmu<Mem_layout::Cache_flush_area, true>::flush_cache();
 132   Mem::isb();
 133
 134   if (m != Kernel_task::kernel_task())
 135     m->make_current();
 136
 137   if (!ntr)
 138     Cpu_call::handle_global_requests();
 139
 140   return ret;
 141 }
 142
 143 //-----------------------------------------------------------------------------
 144 IMPLEMENTATION [arm-!debug]:
 145
 146 extern "C" void sys_kdb_ke()
 147 {}
 148
 149 PRIVATE static inline
 150 int
 151 Thread::call_nested_trap_handler(Trap_state *)
 152 { return -1; }