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

87 lines
2.3 KiB
C++

#include "master.hpp"
namespace factor {
typedef unsigned char UBYTE;
#ifndef UNW_FLAG_EHANDLER
const UBYTE UNW_FLAG_EHANDLER = 0x1;
#endif
struct UNWIND_INFO {
UBYTE Version : 3;
UBYTE Flags : 5;
UBYTE SizeOfProlog;
UBYTE CountOfCodes;
UBYTE FrameRegister : 4;
UBYTE FrameOffset : 4;
ULONG ExceptionHandler;
ULONG ExceptionData[1];
};
struct seh_data {
UNWIND_INFO unwind_info;
RUNTIME_FUNCTION func;
UBYTE handler[32];
};
void factor_vm::c_to_factor_toplevel(cell quot) {
// The annoying thing about Win64 SEH is that the offsets in
// function tables are 32-bit integers, and the exception handler
// itself must reside between the start and end pointers, so
// we stick everything at the beginning of the code heap and
// generate a small trampoline that jumps to the real
// exception handler.
seh_data* seh_area = (seh_data*)code->seh_area;
cell base = code->seg->start;
// Should look at generating this with the Factor assembler
// mov rax,0
seh_area->handler[0] = 0x48;
seh_area->handler[1] = 0xb8;
seh_area->handler[2] = 0x0;
seh_area->handler[3] = 0x0;
seh_area->handler[4] = 0x0;
seh_area->handler[5] = 0x0;
seh_area->handler[6] = 0x0;
seh_area->handler[7] = 0x0;
seh_area->handler[8] = 0x0;
seh_area->handler[9] = 0x0;
// jmp rax
seh_area->handler[10] = 0x48;
seh_area->handler[11] = 0xff;
seh_area->handler[12] = 0xe0;
// Store address of exception handler in the operand of the 'mov'
cell handler = (cell)&factor::exception_handler;
memcpy(&seh_area->handler[2], &handler, sizeof(cell));
UNWIND_INFO* unwind_info = &seh_area->unwind_info;
unwind_info->Version = 1;
unwind_info->Flags = UNW_FLAG_EHANDLER;
unwind_info->SizeOfProlog = 0;
unwind_info->CountOfCodes = 0;
unwind_info->FrameRegister = 0;
unwind_info->FrameOffset = 0;
unwind_info->ExceptionHandler = (DWORD)((cell)&seh_area->handler[0] - base);
unwind_info->ExceptionData[0] = 0;
RUNTIME_FUNCTION* func = &seh_area->func;
func->BeginAddress = 0;
func->EndAddress = (DWORD)(code->seg->end - base);
func->UnwindData = (DWORD)((cell)&seh_area->unwind_info - base);
if (!RtlAddFunctionTable(func, 1, base))
fatal_error("RtlAddFunctionTable() failed", 0);
c_to_factor(quot);
if (!RtlDeleteFunctionTable(func))
fatal_error("RtlDeleteFunctionTable() failed", 0);
}
}