Sharad Khanna 1458c3efff
Fix build issues in frida cmplog for aarch64 (#1813)
* Fix build issues for aarch64

* cargo fmt
2024-01-24 01:18:31 +01:00

889 lines
32 KiB
Rust

//! Functionality for [`frida`](https://frida.re)-based binary-only `CmpLog`.
//! With it, a fuzzer can collect feedback about each compare that happened in the target
//! This allows the fuzzer to potentially solve the compares, if a compare value is directly
//! related to the input.
//! Read the [`RedQueen`](https://www.ndss-symposium.org/ndss-paper/redqueen-fuzzing-with-input-to-state-correspondence/) paper for the general concepts.
#[cfg(all(feature = "cmplog", target_arch = "x86_64"))]
use std::collections::HashMap;
use dynasmrt::dynasm;
#[cfg(target_arch = "aarch64")]
use dynasmrt::{DynasmApi, DynasmLabelApi};
use libafl::{
inputs::{HasTargetBytes, Input},
Error,
};
use libafl_targets::{self, CMPLOG_MAP_W};
use rangemap::RangeMap;
use crate::helper::FridaRuntime;
extern "C" {
/// Tracks cmplog instructions
pub fn __libafl_targets_cmplog_instructions(k: u64, shape: u8, arg1: u64, arg2: u64);
}
#[cfg(target_arch = "aarch64")]
use core::ffi::c_void;
use std::rc::Rc;
use frida_gum::ModuleMap;
#[cfg(target_arch = "x86_64")]
use frida_gum::{instruction_writer::InstructionWriter, stalker::StalkerOutput};
#[cfg(target_arch = "aarch64")]
use frida_gum::{
instruction_writer::{Aarch64Register, IndexMode, InstructionWriter},
stalker::StalkerOutput,
};
use frida_gum_sys::Insn;
#[cfg(all(feature = "cmplog", target_arch = "x86_64"))]
use iced_x86::{
BlockEncoder, Code, DecoderOptions, Instruction, InstructionBlock, MemoryOperand, MemorySize,
OpKind, Register,
};
#[cfg(all(feature = "cmplog", target_arch = "aarch64"))]
use crate::utils::{disas_count, writer_register};
#[cfg(all(feature = "cmplog", target_arch = "aarch64"))]
/// Speciial `CmpLog` Cases for `aarch64`
#[derive(Debug)]
pub enum SpecialCmpLogCase {
/// Test bit and branch if zero
Tbz,
/// Test bit and branch if not zero
Tbnz,
}
#[cfg(all(feature = "cmplog", target_arch = "x86_64"))]
/// Speciial `CmpLog` Cases for `aarch64`
#[derive(Debug)]
pub enum SpecialCmpLogCase {}
#[cfg(target_arch = "aarch64")]
use yaxpeax_arm::armv8::a64::{InstDecoder, Opcode, Operand, ShiftStyle};
#[cfg(target_arch = "x86_64")]
use yaxpeax_x86::long_mode::InstDecoder;
/// The [`frida_gum_sys::GUM_RED_ZONE_SIZE`] casted to [`i32`]
///
/// # Panic
/// In debug mode, will panic on wraparound (which should never happen in practice)
#[cfg(all(feature = "cmplog", target_arch = "aarch64"))]
#[allow(clippy::cast_possible_wrap)]
fn gum_red_zone_size_i32() -> i32 {
debug_assert!(
i32::try_from(frida_gum_sys::GUM_RED_ZONE_SIZE).is_ok(),
"GUM_RED_ZONE_SIZE is bigger than i32::max"
);
frida_gum_sys::GUM_RED_ZONE_SIZE as i32
}
/// The type of an operand loggged during `CmpLog`
#[derive(Debug, Clone, Copy)]
#[cfg(all(feature = "cmplog", target_arch = "aarch64"))]
pub enum CmplogOperandType {
/// A Register
Regid(Aarch64Register),
/// An immediate value
Imm(u64),
/// A constant immediate value
Cimm(u64),
// We don't need a memory type because you cannot directly compare with memory
}
/// The type of an operand loggged during `CmpLog`
#[derive(Debug, Clone, Copy)]
#[cfg(all(feature = "cmplog", target_arch = "x86_64"))]
pub enum CmplogOperandType {
/// A Register
Reg(Register),
/// An immediate value
Imm(u64),
/// A memory operand
Mem(Register, Register, i64, u32, MemorySize), // base, index, disp, scale, mem_size
}
/// `Frida`-based binary-only innstrumentation that logs compares to the fuzzer
/// `LibAFL` can use this knowledge for powerful mutations.
#[derive(Debug)]
#[cfg(target_arch = "aarch64")]
pub struct CmpLogRuntime {
ops_save_register_and_blr_to_populate: Option<Box<[u8]>>,
ops_handle_tbz_masking: Option<Box<[u8]>>,
ops_handle_tbnz_masking: Option<Box<[u8]>>,
}
/// `Frida`-based binary-only innstrumentation that logs compares to the fuzzer
/// `LibAFL` can use this knowledge for powerful mutations.
#[derive(Debug)]
#[cfg(target_arch = "x86_64")]
pub struct CmpLogRuntime {
save_registers: Option<Box<[u8]>>,
restore_registers: Option<Box<[u8]>>,
}
impl FridaRuntime for CmpLogRuntime {
/// Initialize this `CmpLog` runtime.
/// This will generate the instrumentation blobs for the current arch.
fn init(
&mut self,
_gum: &frida_gum::Gum,
_ranges: &RangeMap<usize, (u16, String)>,
_module_map: &Rc<ModuleMap>,
) {
self.generate_instrumentation_blobs();
}
fn pre_exec<I: Input + HasTargetBytes>(&mut self, _input: &I) -> Result<(), Error> {
Ok(())
}
fn post_exec<I: Input + HasTargetBytes>(&mut self, _input: &I) -> Result<(), Error> {
Ok(())
}
}
impl CmpLogRuntime {
/// Create a new [`CmpLogRuntime`]
#[must_use]
#[cfg(target_arch = "aarch64")]
pub fn new() -> CmpLogRuntime {
Self {
ops_save_register_and_blr_to_populate: None,
ops_handle_tbz_masking: None,
ops_handle_tbnz_masking: None,
}
}
/// Create a new [`CmpLogRuntime`]
#[must_use]
#[cfg(target_arch = "x86_64")]
pub fn new() -> CmpLogRuntime {
Self {
save_registers: None,
restore_registers: None,
}
}
/// Call the external function that populates the `cmplog_map` with the relevant values
#[allow(clippy::unused_self)]
#[cfg(target_arch = "aarch64")]
extern "C" fn populate_lists(&mut self, op1: u64, op2: u64, retaddr: u64) {
// log::trace!(
// "entered populate_lists with: {:#02x}, {:#02x}, {:#02x}",
// op1, op2, retaddr
// );
let mut k = (retaddr >> 4) ^ (retaddr << 8);
k &= (CMPLOG_MAP_W as u64) - 1;
unsafe {
__libafl_targets_cmplog_instructions(k, 8, op1, op2);
}
}
#[allow(clippy::unused_self)]
#[cfg(target_arch = "x86_64")]
extern "C" fn populate_lists(size: u8, op1: u64, op2: u64, retaddr: u64) {
// log::trace!(
// "entered populate_lists with: {:#02x}, {:#02x}, {:#02x}",
// op1, op2, retaddr
// );
let mut k = (retaddr >> 4) ^ (retaddr << 8);
k &= (CMPLOG_MAP_W as u64) - 1;
unsafe {
__libafl_targets_cmplog_instructions(k, size, op1, op2);
}
}
/// Generate the instrumentation blobs for the current arch.
#[allow(clippy::similar_names)]
#[cfg(target_arch = "aarch64")]
fn generate_instrumentation_blobs(&mut self) {
macro_rules! blr_to_populate {
($ops:ident) => {dynasm!($ops
; .arch aarch64
; stp x2, x3, [sp, #-0x10]!
; stp x4, x5, [sp, #-0x10]!
; stp x6, x7, [sp, #-0x10]!
; stp x8, x9, [sp, #-0x10]!
; stp x10, x11, [sp, #-0x10]!
; stp x12, x13, [sp, #-0x10]!
; stp x14, x15, [sp, #-0x10]!
; stp x16, x17, [sp, #-0x10]!
; stp x18, x19, [sp, #-0x10]!
; stp x20, x21, [sp, #-0x10]!
; stp x22, x23, [sp, #-0x10]!
; stp x24, x25, [sp, #-0x10]!
; stp x26, x27, [sp, #-0x10]!
; stp x28, x29, [sp, #-0x10]!
; stp x30, xzr, [sp, #-0x10]!
; .dword 0xd53b4218u32 as i32 // mrs x24, nzcv
// jump to rust based population of the lists
; mov x2, x0
; adr x3, >done
; ldr x4, >populate_lists
; ldr x0, >self_addr
; blr x4
// restore the reg state before returning to the caller
; .dword 0xd51b4218u32 as i32 // msr nzcv, x24
; ldp x30, xzr, [sp], #0x10
; ldp x28, x29, [sp], #0x10
; ldp x26, x27, [sp], #0x10
; ldp x24, x25, [sp], #0x10
; ldp x22, x23, [sp], #0x10
; ldp x20, x21, [sp], #0x10
; ldp x18, x19, [sp], #0x10
; ldp x16, x17, [sp], #0x10
; ldp x14, x15, [sp], #0x10
; ldp x12, x13, [sp], #0x10
; ldp x10, x11, [sp], #0x10
; ldp x8, x9, [sp], #0x10
; ldp x6, x7, [sp], #0x10
; ldp x4, x5, [sp], #0x10
; ldp x2, x3, [sp], #0x10
; b >done
; self_addr:
; .qword self as *mut _ as *mut c_void as i64
; populate_lists:
; .qword CmpLogRuntime::populate_lists as *mut c_void as i64
; done:
);};
}
// ldp/stp is more efficient than str/ldr so we use them instead.
macro_rules! tbz_masking {
($ops:ident) => {dynasm!($ops
; .arch aarch64
; stp x5, xzr, [sp, #-0x10]!
; mov x5, #1
; lsl x5, x5, x1
; eor x5, x5, #255
; orr x1, x0, x5
; ldp x5, xzr, [sp], #0x10
);};
}
macro_rules! tbnz_masking {
($ops:ident) => {dynasm!($ops
; .arch aarch64
; stp x5, xzr, [sp, #-0x10]!
; mov x5, #1
; lsl x5, x5, x1
; orr x1, x0, x5
; ldp x5, xzr, [sp], #0x10
);};
}
let mut ops_handle_tbz_masking =
dynasmrt::VecAssembler::<dynasmrt::aarch64::Aarch64Relocation>::new(0);
tbz_masking!(ops_handle_tbz_masking);
let mut ops_handle_tbnz_masking =
dynasmrt::VecAssembler::<dynasmrt::aarch64::Aarch64Relocation>::new(0);
tbnz_masking!(ops_handle_tbnz_masking);
let mut ops_save_register_and_blr_to_populate =
dynasmrt::VecAssembler::<dynasmrt::aarch64::Aarch64Relocation>::new(0);
blr_to_populate!(ops_save_register_and_blr_to_populate);
self.ops_handle_tbz_masking = Some(
ops_handle_tbz_masking
.finalize()
.unwrap()
.into_boxed_slice(),
);
self.ops_handle_tbnz_masking = Some(
ops_handle_tbnz_masking
.finalize()
.unwrap()
.into_boxed_slice(),
);
self.ops_save_register_and_blr_to_populate = Some(
ops_save_register_and_blr_to_populate
.finalize()
.unwrap()
.into_boxed_slice(),
);
}
#[allow(clippy::similar_names)]
#[cfg(all(windows, target_arch = "x86_64"))]
fn generate_instrumentation_blobs(&mut self) {
macro_rules! save_registers {
($ops:ident) => {dynasm!($ops
; .arch x64
; push rcx
; push rdx
; push r8
; push r9
; push r10
; push r11
; push rax
);};
}
let mut save_registers = dynasmrt::VecAssembler::<dynasmrt::x64::X64Relocation>::new(0);
save_registers!(save_registers);
self.save_registers = Some(save_registers.finalize().unwrap().into_boxed_slice());
macro_rules! restore_registers {
($ops:ident) => {dynasm!($ops
; .arch x64
; pop rax
; pop r11
; pop r10
; pop r9
; pop r8
; pop rdx
; pop rcx
);};
}
let mut restore_registers = dynasmrt::VecAssembler::<dynasmrt::x64::X64Relocation>::new(0);
restore_registers!(restore_registers);
self.restore_registers = Some(restore_registers.finalize().unwrap().into_boxed_slice());
}
#[allow(clippy::similar_names)]
#[cfg(all(unix, target_arch = "x86_64"))]
fn generate_instrumentation_blobs(&mut self) {
macro_rules! save_registers {
($ops:ident) => {dynasm!($ops
; .arch x64
; push rax
; push rdi
; push rsi
; push rdx
; push rcx
; push r8
; push r9
);};
}
let mut save_registers = dynasmrt::VecAssembler::<dynasmrt::x64::X64Relocation>::new(0);
save_registers!(save_registers);
self.save_registers = Some(save_registers.finalize().unwrap().into_boxed_slice());
macro_rules! restore_registers {
($ops:ident) => {dynasm!($ops
; .arch x64
; pop r9
; pop r8
; pop rcx
; pop rdx
; pop rsi
; pop rdi
; pop rax
);};
}
let mut restore_registers = dynasmrt::VecAssembler::<dynasmrt::x64::X64Relocation>::new(0);
restore_registers!(restore_registers);
self.restore_registers = Some(restore_registers.finalize().unwrap().into_boxed_slice());
}
/// Get the blob which saves the context, jumps to the populate function and restores the context
#[inline]
#[must_use]
#[cfg(target_arch = "aarch64")]
pub fn ops_save_register_and_blr_to_populate(&self) -> &[u8] {
self.ops_save_register_and_blr_to_populate.as_ref().unwrap()
}
/// Get the blob which handles the tbz opcode masking
#[inline]
#[must_use]
#[cfg(target_arch = "aarch64")]
pub fn ops_handle_tbz_masking(&self) -> &[u8] {
self.ops_handle_tbz_masking.as_ref().unwrap()
}
/// Get the blob which handles the tbnz opcode masking
#[inline]
#[must_use]
#[cfg(target_arch = "aarch64")]
pub fn ops_handle_tbnz_masking(&self) -> &[u8] {
self.ops_handle_tbnz_masking.as_ref().unwrap()
}
/// Emit the instrumentation code which is responsible for operands value extraction and cmplog map population
#[cfg(all(feature = "cmplog", target_arch = "x86_64"))]
#[allow(clippy::too_many_lines)]
#[inline]
pub fn emit_comparison_handling(
&self,
address: u64,
output: &StalkerOutput,
op1: &CmplogOperandType, //first operand of the comparsion
op2: &CmplogOperandType, //second operand of the comparsion
_shift: &Option<SpecialCmpLogCase>,
_special_case: &Option<SpecialCmpLogCase>,
) {
let writer = output.writer();
writer.put_bytes(&self.save_registers.clone().unwrap());
// let int3 = [0xcc];
// writer.put_bytes(&int3);
let mut insts = vec![];
// self ptr is not used so far
let mut size_op = 0;
let arg_reg_1;
let arg_reg_2;
let arg_reg_3;
let arg_reg_4;
let mut tmp_reg = HashMap::new();
tmp_reg.insert(8, Register::RAX);
tmp_reg.insert(4, Register::EAX);
tmp_reg.insert(2, Register::AX);
#[cfg(windows)]
{
arg_reg_1 = Register::CL;
arg_reg_2 = Register::RDX;
arg_reg_3 = Register::R8;
arg_reg_4 = Register::R9;
}
#[cfg(unix)]
{
arg_reg_1 = Register::DL;
arg_reg_2 = Register::RSI;
arg_reg_3 = Register::RDX;
arg_reg_4 = Register::RCX;
}
let mut set_size = |s: usize| {
if size_op == 0 {
size_op = s;
} else {
assert_eq!(size_op, s);
}
};
// we put the operand value into rax and than push it on stack, so the
// only clobbered register is rax, and if actual operand value uses it,
// we simply restore it from stack
for (op_num, op) in [op1, op2].iter().enumerate() {
let op_num: i64 = op_num.try_into().unwrap();
match op {
CmplogOperandType::Reg(reg) => {
let info = reg.info();
set_size(info.size());
let reg_largest = reg.full_register();
if reg_largest == Register::RAX {
insts.push(
// we rely on the fact that latest saved register on stack is rax
Instruction::with1(
Code::Push_rm64,
MemoryOperand::with_base_displ(Register::RSP, op_num * 8),
)
.unwrap(),
);
} else {
insts.push(Instruction::with1(Code::Push_rm64, reg_largest).unwrap());
}
}
CmplogOperandType::Mem(reg_base, reg_index, disp, scale, mem_size) => {
let size;
let inst;
match *mem_size {
MemorySize::UInt64 | MemorySize::Int64 => {
size = 8;
inst = Code::Mov_r64_rm64;
}
MemorySize::UInt32 | MemorySize::Int32 => {
size = 4;
inst = Code::Mov_r32_rm32;
}
MemorySize::UInt16 | MemorySize::Int16 => {
size = 2;
inst = Code::Mov_r16_rm16;
}
_ => {
println!("Invalid memory size");
size = 4;
inst = Code::Push_rm32;
}
}
set_size(size);
let mut disp_adjusted = *disp;
let mut reg_base = *reg_base;
if reg_base == Register::RSP {
// 0x38 is an amount of bytes used by save_registers()
disp_adjusted = disp_adjusted + 0x38 + 8_i64 * op_num;
}
let tmp_reg_adjusted = *tmp_reg.get(&size).unwrap();
// in case of RIP, disp is an absolute address already calculated
// by iced, we can simply load it to rax (but in this case index register must
// be not rax)
if reg_base == Register::RIP {
insts.push(
Instruction::with2(Code::Mov_r64_imm64, Register::RAX, disp_adjusted)
.unwrap(),
);
reg_base = Register::RAX;
disp_adjusted = 0;
}
insts.push(
Instruction::with2(
inst,
tmp_reg_adjusted,
MemoryOperand::with_base_index_scale_displ_size(
reg_base,
*reg_index,
*scale,
disp_adjusted,
1,
),
)
.unwrap(),
);
insts.push(Instruction::with1(Code::Push_rm64, Register::RAX).unwrap());
}
CmplogOperandType::Imm(imm) => {
insts.push(Instruction::with1(Code::Pushq_imm32, *imm as i32).unwrap());
}
}
}
insts.push(Instruction::with2(Code::Mov_r8_imm8, arg_reg_1, size_op as u64).unwrap());
insts.push(Instruction::with1(Code::Pop_r64, arg_reg_2).unwrap());
insts.push(Instruction::with1(Code::Pop_r64, arg_reg_3).unwrap());
insts.push(Instruction::with2(Code::Mov_r64_imm64, arg_reg_4, address).unwrap());
let block = InstructionBlock::new(&insts, 0);
let block = BlockEncoder::encode(64, block, DecoderOptions::NONE).unwrap();
writer.put_bytes(block.code_buffer.as_slice());
writer.put_call_address((CmpLogRuntime::populate_lists as usize).try_into().unwrap());
writer.put_bytes(&self.restore_registers.clone().unwrap());
}
/// Emit the instrumentation code which is responsible for operands value extraction and cmplog map population
#[cfg(all(feature = "cmplog", target_arch = "aarch64"))]
#[allow(clippy::too_many_lines)]
#[inline]
pub fn emit_comparison_handling(
&self,
_address: u64,
output: &StalkerOutput,
op1: &CmplogOperandType, //first operand of the comparsion
op2: &CmplogOperandType, //second operand of the comparsion
_shift: &Option<(ShiftStyle, u8)>,
special_case: &Option<SpecialCmpLogCase>,
) {
let writer = output.writer();
// Preserve x0, x1:
writer.put_stp_reg_reg_reg_offset(
Aarch64Register::X0,
Aarch64Register::X1,
Aarch64Register::Sp,
i64::from(-(16 + gum_red_zone_size_i32())),
IndexMode::PreAdjust,
);
// make sure operand1 value is saved into x0
match op1 {
CmplogOperandType::Imm(value) | CmplogOperandType::Cimm(value) => {
writer.put_ldr_reg_u64(Aarch64Register::X0, *value);
}
CmplogOperandType::Regid(reg) => match *reg {
Aarch64Register::X0 | Aarch64Register::W0 => {}
Aarch64Register::X1 | Aarch64Register::W1 => {
writer.put_mov_reg_reg(Aarch64Register::X0, Aarch64Register::X1);
}
_ => {
if !writer.put_mov_reg_reg(Aarch64Register::X0, *reg) {
writer.put_mov_reg_reg(Aarch64Register::W0, *reg);
}
}
},
}
// make sure operand2 value is saved into x1
match op2 {
CmplogOperandType::Imm(value) | CmplogOperandType::Cimm(value) => {
writer.put_ldr_reg_u64(Aarch64Register::X1, *value);
if let Some(inst) = special_case {
match inst {
SpecialCmpLogCase::Tbz => {
writer.put_bytes(self.ops_handle_tbz_masking());
}
SpecialCmpLogCase::Tbnz => {
writer.put_bytes(self.ops_handle_tbnz_masking());
}
}
}
}
CmplogOperandType::Regid(reg) => match *reg {
Aarch64Register::X1 | Aarch64Register::W1 => {}
Aarch64Register::X0 | Aarch64Register::W0 => {
writer.put_ldr_reg_reg_offset(Aarch64Register::X1, Aarch64Register::Sp, 0u64);
}
_ => {
if !writer.put_mov_reg_reg(Aarch64Register::X1, *reg) {
writer.put_mov_reg_reg(Aarch64Register::W1, *reg);
}
}
},
}
//call cmplog runtime to populate the values map
writer.put_bytes(self.ops_save_register_and_blr_to_populate());
// Restore x0, x1
assert!(writer.put_ldp_reg_reg_reg_offset(
Aarch64Register::X0,
Aarch64Register::X1,
Aarch64Register::Sp,
16 + i64::from(frida_gum_sys::GUM_RED_ZONE_SIZE),
IndexMode::PostAdjust,
));
}
#[cfg(all(feature = "cmplog", target_arch = "x86_64"))]
#[allow(clippy::similar_names)]
#[inline]
/// Check if the current instruction is cmplog relevant one(any opcode which sets the flags)
#[must_use]
pub fn cmplog_is_interesting_instruction(
_decoder: InstDecoder,
_address: u64,
instr: &Insn,
) -> Option<(
CmplogOperandType,
CmplogOperandType,
Option<SpecialCmpLogCase>,
Option<SpecialCmpLogCase>,
)> {
let bytes = instr.bytes();
let mut decoder =
iced_x86::Decoder::with_ip(64, bytes, instr.address(), iced_x86::DecoderOptions::NONE);
if !decoder.can_decode() {
return None;
}
let mut instruction = iced_x86::Instruction::default();
decoder.decode_out(&mut instruction);
match instruction.mnemonic() {
iced_x86::Mnemonic::Cmp | iced_x86::Mnemonic::Sub => {} // continue
_ => return None,
}
if instruction.op_count() != 2 {
return None;
}
// we don't support rip related reference with index register yet
if instruction.memory_base() == Register::RIP
&& instruction.memory_index() != Register::None
{
return None;
}
if instruction.memory_size() == MemorySize::UInt8
|| instruction.memory_size() == MemorySize::Int8
{
return None;
}
let op1 = match instruction.op0_kind() {
OpKind::Register => CmplogOperandType::Reg(instruction.op0_register()),
OpKind::Immediate16
| OpKind::Immediate32
| OpKind::Immediate64
| OpKind::Immediate32to64 => CmplogOperandType::Imm(instruction.immediate(0)),
OpKind::Memory => {
// can't use try_into here, since we need to cast u64 to i64
// which is fine in this case
#[allow(clippy::cast_possible_wrap)]
CmplogOperandType::Mem(
instruction.memory_base(),
instruction.memory_index(),
instruction.memory_displacement64() as i64,
instruction.memory_index_scale(),
instruction.memory_size(),
)
}
_ => {
return None;
}
};
let op2 = match instruction.op1_kind() {
OpKind::Register => CmplogOperandType::Reg(instruction.op1_register()),
OpKind::Immediate16
| OpKind::Immediate32
| OpKind::Immediate64
| OpKind::Immediate32to64 => CmplogOperandType::Imm(instruction.immediate(1)),
OpKind::Memory =>
{
#[allow(clippy::cast_possible_wrap)]
CmplogOperandType::Mem(
instruction.memory_base(),
instruction.memory_index(),
instruction.memory_displacement64() as i64,
instruction.memory_index_scale(),
instruction.memory_size(),
)
}
_ => {
return None;
}
};
// debug print, shows all the cmp instrumented instructions
if log::log_enabled!(log::Level::Debug) {
use iced_x86::{Formatter, NasmFormatter};
let mut formatter = NasmFormatter::new();
let mut output = String::new();
formatter.format(&instruction, &mut output);
log::debug!(
"inst: {:x} {:?}, {:?} {:?}",
instruction.ip(),
output,
op1,
op2
);
}
Some((op1, op2, None, None))
}
#[cfg(all(feature = "cmplog", target_arch = "aarch64"))]
#[allow(clippy::similar_names)]
#[inline]
/// Check if the current instruction is cmplog relevant one(any opcode which sets the flags)
#[must_use]
pub fn cmplog_is_interesting_instruction(
decoder: InstDecoder,
_address: u64,
instr: &Insn,
) -> Option<(
CmplogOperandType,
CmplogOperandType,
Option<(ShiftStyle, u8)>, //possible shifts: everything except MSL
Option<SpecialCmpLogCase>,
)> {
let mut instr = disas_count(&decoder, instr.bytes(), 1)[0];
let operands_len = instr
.operands
.iter()
.position(|item| *item == Operand::Nothing)
.unwrap_or_else(|| 4);
// "cmp" | "ands" | "subs" | "adds" | "negs" | "ngcs" | "sbcs" | "bics" | "cbz"
// | "cbnz" | "tbz" | "tbnz" | "adcs" - yaxpeax aliases insns (i.e., cmp -> subs)
// We only care for compare instructions - aka instructions which set the flags
match instr.opcode {
Opcode::SUBS
| Opcode::ANDS
| Opcode::ADDS
| Opcode::SBCS
| Opcode::BICS
| Opcode::CBZ
| Opcode::CBNZ
| Opcode::TBZ
| Opcode::TBNZ
| Opcode::ADC => (),
_ => return None,
}
// cbz - 1 operand, everything else - 3 operands
let special_case = [
Opcode::CBZ,
Opcode::CBNZ,
Opcode::TBZ,
Opcode::TBNZ,
Opcode::SUBS,
Opcode::ADDS,
Opcode::ANDS,
Opcode::SBCS,
Opcode::BICS,
Opcode::ADCS,
]
.contains(&instr.opcode);
//this check is to ensure that there are the right number of operands
if operands_len != 2 && !special_case {
return None;
}
// handle special opcodes case which have 3 operands, but the 1st(dest) is not important to us
////subs", "adds", "ands", "sbcs", "bics", "adcs"
if [
Opcode::SUBS,
Opcode::ADDS,
Opcode::ANDS,
Opcode::SBCS,
Opcode::BICS,
Opcode::ADCS,
]
.contains(&instr.opcode)
{
//remove the dest operand from the list
instr.operands.rotate_left(1);
instr.operands[3] = Operand::Nothing;
}
// cbz marked as special since there is only 1 operand
#[allow(clippy::cast_sign_loss)]
let special_case = matches!(instr.opcode, Opcode::CBZ | Opcode::CBNZ);
#[allow(clippy::cast_sign_loss, clippy::similar_names)]
let operand1 = match instr.operands[0] {
//the only possibilities are registers for the first operand
//precompute the aarch64 frida register because it is ambiguous if register=31 means xzr or sp in yaxpeax
Operand::Register(sizecode, reg) => Some(CmplogOperandType::Regid(writer_register(
reg, sizecode, true,
))),
Operand::RegisterOrSP(sizecode, reg) => Some(CmplogOperandType::Regid(
writer_register(reg, sizecode, false),
)),
_ => panic!("First argument is not a register"), //this should never be possible in arm64
};
#[allow(clippy::cast_sign_loss)]
let operand2 = if special_case {
Some((CmplogOperandType::Imm(0), None))
} else {
match instr.operands[1] {
Operand::Register(sizecode, reg) => Some((
CmplogOperandType::Regid(writer_register(reg, sizecode, true)),
None,
)),
Operand::ImmShift(imm, shift) => {
Some((CmplogOperandType::Imm((imm as u64) << shift), None))
} //precalculate the shift
Operand::RegShift(shiftstyle, amount, regsize, reg) => {
let reg = CmplogOperandType::Regid(writer_register(reg, regsize, true));
let shift = (shiftstyle, amount);
Some((reg, Some(shift)))
}
Operand::Immediate(imm) => Some((CmplogOperandType::Imm(imm as u64), None)),
_ => panic!("Second argument could not be decoded"),
}
};
// tbz will need to have special handling at emit time(masking operand1 value with operand2)
let special_case = match instr.opcode {
Opcode::TBZ => Some(SpecialCmpLogCase::Tbz),
Opcode::TBNZ => Some(SpecialCmpLogCase::Tbnz),
_ => None,
};
if let Some(op1) = operand1 {
operand2.map(|op2| (op1, op2.0, op2.1, special_case))
} else {
None
}
}
}
impl Default for CmpLogRuntime {
#[inline]
fn default() -> Self {
Self::new()
}
}