1 files changed, 462 insertions, 0 deletions

diff --git a/libunwindstack/DwarfOp.cpp b/libunwindstack/DwarfOp.cpp
new file mode 100644
index 000000000..507ca083d
--- /dev/null
+++ b/libunwindstack/DwarfOp.cpp
@@ -0,0 +1,462 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>
+
+#include <deque>
+#include <string>
+#include <vector>
+
+#include <android-base/stringprintf.h>
+
+#include "DwarfError.h"
+#include "DwarfMemory.h"
+#include "DwarfOp.h"
+#include "Log.h"
+#include "Memory.h"
+#include "Regs.h"
+
+template <typename AddressType>
+constexpr typename DwarfOp<AddressType>::OpCallback DwarfOp<AddressType>::kCallbackTable[256];
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::Eval(uint64_t start, uint64_t end, uint8_t dwarf_version) {
+  uint32_t iterations = 0;
+  is_register_ = false;
+  stack_.clear();
+  memory_->set_cur_offset(start);
+  while (memory_->cur_offset() < end) {
+    if (!Decode(dwarf_version)) {
+      return false;
+    }
+    // To protect against a branch that creates an infinite loop,
+    // terminate if the number of iterations gets too high.
+    if (iterations++ == 1000) {
+      last_error_ = DWARF_ERROR_TOO_MANY_ITERATIONS;
+      return false;
+    }
+  }
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::Decode(uint8_t dwarf_version) {
+  last_error_ = DWARF_ERROR_NONE;
+  if (!memory_->ReadBytes(&cur_op_, 1)) {
+    last_error_ = DWARF_ERROR_MEMORY_INVALID;
+    return false;
+  }
+
+  const auto* op = &kCallbackTable[cur_op_];
+  const auto handle_func = op->handle_func;
+  if (handle_func == nullptr) {
+    last_error_ = DWARF_ERROR_ILLEGAL_VALUE;
+    return false;
+  }
+
+  // Check for an unsupported opcode.
+  if (dwarf_version < op->supported_version) {
+    last_error_ = DWARF_ERROR_ILLEGAL_VALUE;
+    return false;
+  }
+
+  // Make sure that the required number of stack elements is available.
+  if (stack_.size() < op->num_required_stack_values) {
+    last_error_ = DWARF_ERROR_STACK_INDEX_NOT_VALID;
+    return false;
+  }
+
+  operands_.clear();
+  for (size_t i = 0; i < op->num_operands; i++) {
+    uint64_t value;
+    if (!memory_->ReadEncodedValue<AddressType>(op->operands[i], &value)) {
+      last_error_ = DWARF_ERROR_MEMORY_INVALID;
+      return false;
+    }
+    operands_.push_back(value);
+  }
+  return (this->*handle_func)();
+}
+
+template <typename AddressType>
+void DwarfOp<AddressType>::GetLogInfo(uint64_t start, uint64_t end,
+                                      std::vector<std::string>* lines) {
+  memory_->set_cur_offset(start);
+  while (memory_->cur_offset() < end) {
+    uint8_t cur_op;
+    if (!memory_->ReadBytes(&cur_op, 1)) {
+      return;
+    }
+
+    std::string raw_string(android::base::StringPrintf("Raw Data: 0x%02x", cur_op));
+    std::string log_string;
+    const auto* op = &kCallbackTable[cur_op];
+    if (op->handle_func == nullptr) {
+      log_string = "Illegal";
+    } else {
+      log_string = op->name;
+      uint64_t start_offset = memory_->cur_offset();
+      for (size_t i = 0; i < op->num_operands; i++) {
+        uint64_t value;
+        if (!memory_->ReadEncodedValue<AddressType>(op->operands[i], &value)) {
+          return;
+        }
+        log_string += ' ' + std::to_string(value);
+      }
+      uint64_t end_offset = memory_->cur_offset();
+
+      memory_->set_cur_offset(start_offset);
+      for (size_t i = start_offset; i < end_offset; i++) {
+        uint8_t byte;
+        if (!memory_->ReadBytes(&byte, 1)) {
+          return;
+        }
+        raw_string += android::base::StringPrintf(" 0x%02x", byte);
+      }
+      memory_->set_cur_offset(end_offset);
+    }
+    lines->push_back(std::move(log_string));
+    lines->push_back(std::move(raw_string));
+  }
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_deref() {
+  // Read the address and dereference it.
+  AddressType addr = StackPop();
+  AddressType value;
+  if (!regular_memory()->Read(addr, &value, sizeof(value))) {
+    last_error_ = DWARF_ERROR_MEMORY_INVALID;
+    return false;
+  }
+  stack_.push_front(value);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_deref_size() {
+  AddressType bytes_to_read = OperandAt(0);
+  if (bytes_to_read > sizeof(AddressType) || bytes_to_read == 0) {
+    last_error_ = DWARF_ERROR_ILLEGAL_VALUE;
+    return false;
+  }
+  // Read the address and dereference it.
+  AddressType addr = StackPop();
+  AddressType value = 0;
+  if (!regular_memory()->Read(addr, &value, bytes_to_read)) {
+    last_error_ = DWARF_ERROR_MEMORY_INVALID;
+    return false;
+  }
+  stack_.push_front(value);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_push() {
+  // Push all of the operands.
+  for (auto operand : operands_) {
+    stack_.push_front(operand);
+  }
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_dup() {
+  stack_.push_front(StackAt(0));
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_drop() {
+  StackPop();
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_over() {
+  stack_.push_front(StackAt(1));
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_pick() {
+  AddressType index = OperandAt(0);
+  if (index > StackSize()) {
+    last_error_ = DWARF_ERROR_STACK_INDEX_NOT_VALID;
+    return false;
+  }
+  stack_.push_front(StackAt(index));
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_swap() {
+  AddressType old_value = stack_[0];
+  stack_[0] = stack_[1];
+  stack_[1] = old_value;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_rot() {
+  AddressType top = stack_[0];
+  stack_[0] = stack_[1];
+  stack_[1] = stack_[2];
+  stack_[2] = top;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_abs() {
+  SignedType signed_value = static_cast<SignedType>(stack_[0]);
+  if (signed_value < 0) {
+    signed_value = -signed_value;
+  }
+  stack_[0] = static_cast<AddressType>(signed_value);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_and() {
+  AddressType top = StackPop();
+  stack_[0] &= top;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_div() {
+  AddressType top = StackPop();
+  if (top == 0) {
+    last_error_ = DWARF_ERROR_ILLEGAL_VALUE;
+    return false;
+  }
+  SignedType signed_divisor = static_cast<SignedType>(top);
+  SignedType signed_dividend = static_cast<SignedType>(stack_[0]);
+  stack_[0] = static_cast<AddressType>(signed_dividend / signed_divisor);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_minus() {
+  AddressType top = StackPop();
+  stack_[0] -= top;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_mod() {
+  AddressType top = StackPop();
+  if (top == 0) {
+    last_error_ = DWARF_ERROR_ILLEGAL_VALUE;
+    return false;
+  }
+  stack_[0] %= top;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_mul() {
+  AddressType top = StackPop();
+  stack_[0] *= top;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_neg() {
+  SignedType signed_value = static_cast<SignedType>(stack_[0]);
+  stack_[0] = static_cast<AddressType>(-signed_value);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_not() {
+  stack_[0] = ~stack_[0];
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_or() {
+  AddressType top = StackPop();
+  stack_[0] |= top;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_plus() {
+  AddressType top = StackPop();
+  stack_[0] += top;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_plus_uconst() {
+  stack_[0] += OperandAt(0);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_shl() {
+  AddressType top = StackPop();
+  stack_[0] <<= top;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_shr() {
+  AddressType top = StackPop();
+  stack_[0] >>= top;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_shra() {
+  AddressType top = StackPop();
+  SignedType signed_value = static_cast<SignedType>(stack_[0]) >> top;
+  stack_[0] = static_cast<AddressType>(signed_value);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_xor() {
+  AddressType top = StackPop();
+  stack_[0] ^= top;
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_bra() {
+  // Requires one stack element.
+  AddressType top = StackPop();
+  int16_t offset = static_cast<int16_t>(OperandAt(0));
+  uint64_t cur_offset;
+  if (top != 0) {
+    cur_offset = memory_->cur_offset() + offset;
+  } else {
+    cur_offset = memory_->cur_offset() - offset;
+  }
+  memory_->set_cur_offset(cur_offset);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_eq() {
+  AddressType top = StackPop();
+  stack_[0] = bool_to_dwarf_bool(stack_[0] == top);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_ge() {
+  AddressType top = StackPop();
+  stack_[0] = bool_to_dwarf_bool(stack_[0] >= top);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_gt() {
+  AddressType top = StackPop();
+  stack_[0] = bool_to_dwarf_bool(stack_[0] > top);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_le() {
+  AddressType top = StackPop();
+  stack_[0] = bool_to_dwarf_bool(stack_[0] <= top);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_lt() {
+  AddressType top = StackPop();
+  stack_[0] = bool_to_dwarf_bool(stack_[0] < top);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_ne() {
+  AddressType top = StackPop();
+  stack_[0] = bool_to_dwarf_bool(stack_[0] != top);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_skip() {
+  int16_t offset = static_cast<int16_t>(OperandAt(0));
+  uint64_t cur_offset = memory_->cur_offset() + offset;
+  memory_->set_cur_offset(cur_offset);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_lit() {
+  stack_.push_front(cur_op() - 0x30);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_reg() {
+  is_register_ = true;
+  stack_.push_front(cur_op() - 0x50);
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_regx() {
+  is_register_ = true;
+  stack_.push_front(OperandAt(0));
+  return true;
+}
+
+// It's not clear for breg/bregx, if this op should read the current
+// value of the register, or where we think that register is located.
+// For simplicity, the code will read the value before doing the unwind.
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_breg() {
+  uint16_t reg = cur_op() - 0x70;
+  if (reg >= regs_->total_regs()) {
+    last_error_ = DWARF_ERROR_ILLEGAL_VALUE;
+    return false;
+  }
+  stack_.push_front((*regs_)[reg] + OperandAt(0));
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_bregx() {
+  AddressType reg = OperandAt(0);
+  if (reg >= regs_->total_regs()) {
+    last_error_ = DWARF_ERROR_ILLEGAL_VALUE;
+    return false;
+  }
+  stack_.push_front((*regs_)[reg] + OperandAt(1));
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_nop() {
+  return true;
+}
+
+template <typename AddressType>
+bool DwarfOp<AddressType>::op_not_implemented() {
+  last_error_ = DWARF_ERROR_NOT_IMPLEMENTED;
+  return false;
+}
+
+// Explicitly instantiate DwarfOp.
+template class DwarfOp<uint32_t>;
+template class DwarfOp<uint64_t>;