vm/os-windows-nt-x86.64.cpp

   1 #include "master.hpp"
   2
   3 namespace factor {
   4
   5 typedef unsigned char UBYTE;
   6
   7 const UBYTE UNW_FLAG_EHANDLER = 0x1;
   8
   9 struct UNWIND_INFO {
  10         UBYTE Version:3;
  11         UBYTE Flags:5;
  12         UBYTE SizeOfProlog;
  13         UBYTE CountOfCodes;
  14         UBYTE FrameRegister:4;
  15         UBYTE FrameOffset:4;
  16         ULONG ExceptionHandler;
  17         ULONG ExceptionData[1];
  18 };
  19
  20 struct seh_data {
  21         UNWIND_INFO unwind_info;
  22         RUNTIME_FUNCTION func;
  23         UBYTE handler[32];
  24 };
  25
  26 void factor_vm::c_to_factor_toplevel(cell quot)
  27 {
  28         /* The annoying thing about Win64 SEH is that the offsets in
  29          * function tables are 32-bit integers, and the exception handler
  30          * itself must reside between the start and end pointers, so
  31          * we stick everything at the beginning of the code heap and
  32          * generate a small trampoline that jumps to the real
  33          * exception handler. */
  34
  35         seh_data *seh_area = (seh_data *)code->seh_area;
  36         cell base = code->seg->start;
  37
  38         /* Should look at generating this with the Factor assembler */
  39
  40         /* mov rax,0 */
  41         seh_area->handler[0] = 0x48;
  42         seh_area->handler[1] = 0xb8;
  43         seh_area->handler[2] = 0x0;
  44         seh_area->handler[3] = 0x0;
  45         seh_area->handler[4] = 0x0;
  46         seh_area->handler[5] = 0x0;
  47         seh_area->handler[6] = 0x0;
  48         seh_area->handler[7] = 0x0;
  49         seh_area->handler[8] = 0x0;
  50         seh_area->handler[9] = 0x0;
  51
  52         /* jmp rax */
  53         seh_area->handler[10] = 0x48;
  54         seh_area->handler[11] = 0xff;
  55         seh_area->handler[12] = 0xe0;
  56
  57         /* Store address of exception handler in the operand of the 'mov' */
  58         cell handler = (cell)&factor::exception_handler;
  59         memcpy(&seh_area->handler[2],&handler,sizeof(cell));
  60
  61         UNWIND_INFO *unwind_info = &seh_area->unwind_info;
  62         unwind_info->Version = 1;
  63         unwind_info->Flags = UNW_FLAG_EHANDLER;
  64         unwind_info->SizeOfProlog = 0;
  65         unwind_info->CountOfCodes = 0;
  66         unwind_info->FrameRegister = 0;
  67         unwind_info->FrameOffset = 0;
  68         unwind_info->ExceptionHandler = (DWORD)((cell)&seh_area->handler[0] - base);
  69         unwind_info->ExceptionData[0] = 0;
  70
  71         RUNTIME_FUNCTION *func = &seh_area->func;
  72         func->BeginAddress = 0;
  73         func->EndAddress = (DWORD)(code->seg->end - base);
  74         func->UnwindData = (DWORD)((cell)&seh_area->unwind_info - base);
  75
  76         if(!RtlAddFunctionTable(func,1,base))
  77                 fatal_error("RtlAddFunctionTable() failed",0);
  78
  79         c_to_factor(quot);
  80
  81         if(!RtlDeleteFunctionTable(func))
  82                 fatal_error("RtlDeleteFunctionTable() failed",0);
  83 }
  84
  85 }