upload android base code part6

android/system/core/libunwindstack/Elf.cpp

@@ -0,0 +1,174 @@
+/*
+ * Copyright (C) 2016 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 <elf.h>
+#include <string.h>
+
+#include <memory>
+#include <string>
+
+#define LOG_TAG "unwind"
+#include <log/log.h>
+
+#include <unwindstack/Elf.h>
+#include <unwindstack/ElfInterface.h>
+#include <unwindstack/MapInfo.h>
+#include <unwindstack/Memory.h>
+#include <unwindstack/Regs.h>
+
+#include "ElfInterfaceArm.h"
+#include "Machine.h"
+#include "Symbols.h"
+
+namespace unwindstack {
+
+bool Elf::Init() {
+  if (!memory_) {
+    return false;
+  }
+
+  interface_.reset(CreateInterfaceFromMemory(memory_.get()));
+  if (!interface_) {
+    return false;
+  }
+
+  valid_ = interface_->Init();
+  if (valid_) {
+    interface_->InitHeaders();
+  } else {
+    interface_.reset(nullptr);
+  }
+  return valid_;
+}
+
+// It is expensive to initialize the .gnu_debugdata section. Provide a method
+// to initialize this data separately.
+void Elf::InitGnuDebugdata() {
+  if (!valid_ || interface_->gnu_debugdata_offset() == 0) {
+    return;
+  }
+
+  gnu_debugdata_memory_.reset(interface_->CreateGnuDebugdataMemory());
+  gnu_debugdata_interface_.reset(CreateInterfaceFromMemory(gnu_debugdata_memory_.get()));
+  ElfInterface* gnu = gnu_debugdata_interface_.get();
+  if (gnu == nullptr) {
+    return;
+  }
+  if (gnu->Init()) {
+    gnu->InitHeaders();
+  } else {
+    // Free all of the memory associated with the gnu_debugdata section.
+    gnu_debugdata_memory_.reset(nullptr);
+    gnu_debugdata_interface_.reset(nullptr);
+  }
+}
+
+bool Elf::GetSoname(std::string* name) {
+  return valid_ && interface_->GetSoname(name);
+}
+
+uint64_t Elf::GetRelPc(uint64_t pc, const MapInfo* map_info) {
+  uint64_t load_bias = 0;
+  if (valid()) {
+    load_bias = interface_->load_bias();
+  }
+
+  return pc - map_info->start + load_bias + map_info->elf_offset;
+}
+
+bool Elf::GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset) {
+  return valid_ && (interface_->GetFunctionName(addr, name, func_offset) ||
+                    (gnu_debugdata_interface_ &&
+                     gnu_debugdata_interface_->GetFunctionName(addr, name, func_offset)));
+}
+
+bool Elf::Step(uint64_t rel_pc, Regs* regs, Memory* process_memory) {
+  return valid_ && (regs->StepIfSignalHandler(rel_pc, this, process_memory) ||
+                    interface_->Step(rel_pc, regs, process_memory) ||
+                    (gnu_debugdata_interface_ &&
+                     gnu_debugdata_interface_->Step(rel_pc, regs, process_memory)));
+}
+
+uint64_t Elf::GetLoadBias() {
+  if (!valid_) return 0;
+  return interface_->load_bias();
+}
+
+bool Elf::IsValidElf(Memory* memory) {
+  if (memory == nullptr) {
+    return false;
+  }
+
+  // Verify that this is a valid elf file.
+  uint8_t e_ident[SELFMAG + 1];
+  if (!memory->Read(0, e_ident, SELFMAG)) {
+    return false;
+  }
+
+  if (memcmp(e_ident, ELFMAG, SELFMAG) != 0) {
+    return false;
+  }
+  return true;
+}
+
+ElfInterface* Elf::CreateInterfaceFromMemory(Memory* memory) {
+  if (!IsValidElf(memory)) {
+    return nullptr;
+  }
+
+  std::unique_ptr<ElfInterface> interface;
+  if (!memory->Read(EI_CLASS, &class_type_, 1)) {
+    return nullptr;
+  }
+  if (class_type_ == ELFCLASS32) {
+    Elf32_Half e_machine;
+    if (!memory->Read(EI_NIDENT + sizeof(Elf32_Half), &e_machine, sizeof(e_machine))) {
+      return nullptr;
+    }
+
+    if (e_machine != EM_ARM && e_machine != EM_386) {
+      // Unsupported.
+      ALOGI("32 bit elf that is neither arm nor x86: e_machine = %d\n", e_machine);
+      return nullptr;
+    }
+
+    machine_type_ = e_machine;
+    if (e_machine == EM_ARM) {
+      interface.reset(new ElfInterfaceArm(memory));
+    } else if (e_machine == EM_386) {
+      interface.reset(new ElfInterface32(memory));
+    } else {
+      ALOGI("32 bit elf that is neither arm nor x86: e_machine = %d\n", e_machine);
+      return nullptr;
+    }
+  } else if (class_type_ == ELFCLASS64) {
+    Elf64_Half e_machine;
+    if (!memory->Read(EI_NIDENT + sizeof(Elf64_Half), &e_machine, sizeof(e_machine))) {
+      return nullptr;
+    }
+    if (e_machine != EM_AARCH64 && e_machine != EM_X86_64) {
+      // Unsupported.
+      ALOGI("64 bit elf that is neither aarch64 nor x86_64: e_machine = %d\n", e_machine);
+      return nullptr;
+    }
+    machine_type_ = e_machine;
+    interface.reset(new ElfInterface64(memory));
+  }
+
+  return interface.release();
+}
+
+}  // namespace unwindstack