static int check_dynamic_opr(ud_t *udptr)
{
//obtain the operand of current instruction
const ud_operand_t *opr = ud_insn_opr(udptr, 0);
if (opr == NULL) {
fprintf(stderr, "Bad jmp instruction at address %p.\n", (void *)ud_insn_off(udptr));
exit(1);
}
//if it is a dynamic operand
if (opr->type == UD_OP_MEM || opr->type == UD_OP_PTR || opr->type == UD_OP_REG)
return 1;
return 0;
}
virtual void Apply() override
{
if (applied_)
{
return;
}
if (detached_)
{
HADESMEM_DETAIL_ASSERT(false);
return;
}
// Reset the trampolines here because we don't do it in remove, otherwise
// there's a potential race condition where we want to unhook and unload
// safely, so we unhook the function, then try waiting on our ref count to
// become zero, but we haven't actually called the trampoline yet, so we end
// up jumping to the memory we just free'd!
trampoline_ = nullptr;
trampolines_.clear();
stub_gate_ = nullptr;
SuspendedProcess const suspended_process{process_->GetId()};
std::uint32_t const kMaxInstructionLen = 15;
std::uint32_t const kTrampSize = kMaxInstructionLen * 3;
trampoline_ = std::make_unique<Allocator>(*process_, kTrampSize);
auto tramp_cur = static_cast<std::uint8_t*>(trampoline_->GetBase());
auto const detour_raw = detour_.target<DetourFuncRawT>();
if (detour_raw || detour_)
{
HADESMEM_DETAIL_TRACE_FORMAT_A(
"Target = %p, Detour = %p, Trampoline = %p.",
target_,
detour_raw,
trampoline_->GetBase());
}
else
{
HADESMEM_DETAIL_TRACE_FORMAT_A(
"Target = %p, Detour = INVALID, Trampoline = %p.",
target_,
trampoline_->GetBase());
}
auto const buffer =
ReadVector<std::uint8_t>(*process_, target_, kTrampSize);
ud_t ud_obj;
ud_init(&ud_obj);
ud_set_input_buffer(&ud_obj, buffer.data(), buffer.size());
ud_set_syntax(&ud_obj, UD_SYN_INTEL);
ud_set_pc(&ud_obj, reinterpret_cast<std::uint64_t>(target_));
#if defined(HADESMEM_DETAIL_ARCH_X64)
ud_set_mode(&ud_obj, 64);
#elif defined(HADESMEM_DETAIL_ARCH_X86)
ud_set_mode(&ud_obj, 32);
#else
#error "[HadesMem] Unsupported architecture."
#endif
stub_gate_ = detail::AllocatePageNear(*process_, target_);
std::size_t const patch_size = GetPatchSize();
std::uint32_t instr_size = 0;
do
{
std::uint32_t const len = ud_disassemble(&ud_obj);
if (len == 0)
{
HADESMEM_DETAIL_THROW_EXCEPTION(Error{}
<< ErrorString{"Disassembly failed."});
}
#if !defined(HADESMEM_NO_TRACE)
char const* const asm_str = ud_insn_asm(&ud_obj);
char const* const asm_bytes_str = ud_insn_hex(&ud_obj);
HADESMEM_DETAIL_TRACE_FORMAT_A(
"%s. [%s].",
(asm_str ? asm_str : "Invalid."),
(asm_bytes_str ? asm_bytes_str : "Invalid."));
#endif
ud_operand_t const* const op = ud_insn_opr(&ud_obj, 0);
bool is_jimm = op && op->type == UD_OP_JIMM;
// Handle JMP QWORD PTR [RIP+Rel32]. Necessary for hook chain support.
bool is_jmem = op && op->type == UD_OP_MEM && op->base == UD_R_RIP &&
op->index == UD_NONE && op->scale == 0 && op->size == 0x40;
if ((ud_obj.mnemonic == UD_Ijmp || ud_obj.mnemonic == UD_Icall) && op &&
(is_jimm || is_jmem))
{
std::uint16_t const size = is_jimm ? op->size : op->offset;
HADESMEM_DETAIL_TRACE_FORMAT_A("Operand/offset size is %hu.", size);
std::int64_t const insn_target = [&]() -> std::int64_t
{
switch (size)
{
case sizeof(std::int8_t) * CHAR_BIT:
return op->lval.sbyte;
case sizeof(std::int16_t) * CHAR_BIT:
return op->lval.sword;
case sizeof(std::int32_t) * CHAR_BIT:
return op->lval.sdword;
case sizeof(std::int64_t) * CHAR_BIT:
return op->lval.sqword;
default:
HADESMEM_DETAIL_ASSERT(false);
HADESMEM_DETAIL_THROW_EXCEPTION(
Error{} << ErrorString{"Unknown instruction size."});
}
}();
auto const resolve_rel =
[](std::uint64_t base, std::int64_t target, std::uint32_t insn_len)
{
return reinterpret_cast<std::uint8_t*>(
static_cast<std::uintptr_t>(base)) +
target + insn_len;
};
std::uint64_t const insn_base = ud_insn_off(&ud_obj);
std::uint32_t const insn_len = ud_insn_len(&ud_obj);
auto const resolved_target =
resolve_rel(insn_base, insn_target, insn_len);
void* const jump_target =
is_jimm ? resolved_target : Read<void*>(*process_, resolved_target);
HADESMEM_DETAIL_TRACE_FORMAT_A("Jump/call target = %p.", jump_target);
if (ud_obj.mnemonic == UD_Ijmp)
{
HADESMEM_DETAIL_TRACE_A("Writing resolved jump.");
tramp_cur += detail::WriteJump(
*process_, tramp_cur, jump_target, true, &trampolines_);
}
else
{
HADESMEM_DETAIL_ASSERT(ud_obj.mnemonic == UD_Icall);
HADESMEM_DETAIL_TRACE_A("Writing resolved call.");
tramp_cur +=
detail::WriteCall(*process_, tramp_cur, jump_target, trampolines_);
}
}
else
{
std::uint8_t const* const raw = ud_insn_ptr(&ud_obj);
Write(*process_, tramp_cur, raw, raw + len);
tramp_cur += len;
}
instr_size += len;
} while (instr_size < patch_size);
HADESMEM_DETAIL_TRACE_A("Writing jump back to original code.");
tramp_cur +=
detail::WriteJump(*process_,
tramp_cur,
reinterpret_cast<std::uint8_t*>(target_) + instr_size,
true,
&trampolines_);
FlushInstructionCache(
*process_, trampoline_->GetBase(), trampoline_->GetSize());
detail::WriteStubGate<TargetFuncT>(*process_,
stub_gate_->GetBase(),
&*stub_,
&GetOriginalArbitraryUserPtrPtr);
orig_ = ReadVector<std::uint8_t>(*process_, target_, patch_size);
detail::VerifyPatchThreads(process_->GetId(), target_, orig_.size());
WritePatch();
FlushInstructionCache(*process_, target_, instr_size);
applied_ = true;
}
target_addr_t
DisassemblerX8664::GetInstructionTargetAddress(CpuState* state) const
{
ud_mnemonic_code mnemonic = ud_insn_mnemonic(fUdisData);
if (mnemonic != UD_Icall && mnemonic != UD_Ijmp)
return 0;
CpuStateX8664* x64State = dynamic_cast<CpuStateX8664*>(state);
if (x64State == NULL)
return 0;
target_addr_t targetAddress = 0;
const struct ud_operand* op = ud_insn_opr(fUdisData, 0);
switch (op->type) {
case UD_OP_REG:
{
targetAddress = x64State->IntRegisterValue(
RegisterNumberFromUdisIndex(op->base));
targetAddress += op->offset;
}
break;
case UD_OP_MEM:
{
targetAddress = x64State->IntRegisterValue(
RegisterNumberFromUdisIndex(op->base));
targetAddress += x64State->IntRegisterValue(
RegisterNumberFromUdisIndex(op->index))
* op->scale;
off_t offset = 0;
switch (op->offset) {
case 8:
offset = op->lval.sbyte;
break;
case 16:
offset = op->lval.sword;
break;
case 32:
offset = op->lval.sdword;
break;
case 64:
offset = op->lval.sqword;
break;
}
targetAddress += offset;
}
break;
case UD_OP_JIMM:
{
targetAddress = ud_insn_off(fUdisData) + ud_insn_len(fUdisData);
if (op->size == 32)
targetAddress += op->lval.sdword;
else
targetAddress += op->lval.sqword;
}
break;
case UD_OP_IMM:
case UD_OP_CONST:
{
if (op->size == 32)
targetAddress = op->lval.udword;
else if (op->size == 64)
targetAddress = op->lval.uqword;
}
break;
default:
break;
}
return targetAddress;
}
