Verify that the elf matches the expected arch.

To avoid a case where a malicious app might try and trick the system to
create an elf and register object that mismatches, always verify that they
are the same arch.

Test: Ran unit tests.
Change-Id: I66978e9e02f8e4f396856912e7019528ead4838e

5 files changed, 22 insertions, 11 deletions

diff --git a/libunwindstack/include/unwindstack/DexFiles.h b/libunwindstack/include/unwindstack/DexFiles.h
index c2fde74efc..c202a334de 100644
--- a/libunwindstack/include/unwindstack/DexFiles.h
+++ b/libunwindstack/include/unwindstack/DexFiles.h
@@ -47,8 +47,6 @@ class DexFiles : public Global {
   void GetMethodInformation(Maps* maps, MapInfo* info, uint64_t dex_pc, std::string* method_name,
                             uint64_t* method_offset);
 
-  void SetArch(ArchEnum arch);
-
  private:
   void Init(Maps* maps);
 
@@ -64,6 +62,8 @@ class DexFiles : public Global {
 
   bool ReadVariableData(uint64_t ptr_offset) override;
 
+  void ProcessArch() override;
+
   std::mutex lock_;
   bool initialized_ = false;
   std::unordered_map<uint64_t, DexFile*> files_;
diff --git a/libunwindstack/include/unwindstack/Elf.h b/libunwindstack/include/unwindstack/Elf.h
index 24cabf2205..e5b0a89c9b 100644
--- a/libunwindstack/include/unwindstack/Elf.h
+++ b/libunwindstack/include/unwindstack/Elf.h
@@ -57,6 +57,8 @@ class Elf {
 
   void InitGnuDebugdata();
 
+  void Invalidate();
+
   bool GetSoname(std::string* name);
 
   bool GetFunctionName(uint64_t addr, std::string* name, uint64_t* func_offset);
diff --git a/libunwindstack/include/unwindstack/Global.h b/libunwindstack/include/unwindstack/Global.h
index 70e3ddd455..a7e6c15baa 100644
--- a/libunwindstack/include/unwindstack/Global.h
+++ b/libunwindstack/include/unwindstack/Global.h
@@ -25,6 +25,7 @@
 #include <unordered_map>
 #include <vector>
 
+#include <unwindstack/Elf.h>
 #include <unwindstack/Memory.h>
 
 namespace unwindstack {
@@ -39,12 +40,20 @@ class Global {
   Global(std::shared_ptr<Memory>& memory, std::vector<std::string>& search_libs);
   virtual ~Global() = default;
 
+  void SetArch(ArchEnum arch);
+
+  ArchEnum arch() { return arch_; }
+
  protected:
   uint64_t GetVariableOffset(MapInfo* info, const std::string& variable);
   void FindAndReadVariable(Maps* maps, const char* variable);
 
   virtual bool ReadVariableData(uint64_t offset) = 0;
 
+  virtual void ProcessArch() = 0;
+
+  ArchEnum arch_ = ARCH_UNKNOWN;
+
   std::shared_ptr<Memory> memory_;
   std::vector<std::string> search_libs_;
 };
diff --git a/libunwindstack/include/unwindstack/JitDebug.h b/libunwindstack/include/unwindstack/JitDebug.h
index ccb473f7ef..f64b04f0a6 100644
--- a/libunwindstack/include/unwindstack/JitDebug.h
+++ b/libunwindstack/include/unwindstack/JitDebug.h
@@ -42,17 +42,9 @@ class JitDebug : public Global {
 
   Elf* GetElf(Maps* maps, uint64_t pc);
 
-  void SetArch(ArchEnum arch);
-
  private:
   void Init(Maps* maps);
 
-  uint64_t entry_addr_ = 0;
-  bool initialized_ = false;
-  std::vector<Elf*> elf_list_;
-
-  std::mutex lock_;
-
   uint64_t (JitDebug::*read_descriptor_func_)(uint64_t) = nullptr;
   uint64_t (JitDebug::*read_entry_func_)(uint64_t*, uint64_t*) = nullptr;
 
@@ -64,6 +56,14 @@ class JitDebug : public Global {
   uint64_t ReadEntry64(uint64_t* start, uint64_t* size);
 
   bool ReadVariableData(uint64_t ptr_offset) override;
+
+  void ProcessArch() override;
+
+  uint64_t entry_addr_ = 0;
+  bool initialized_ = false;
+  std::vector<Elf*> elf_list_;
+
+  std::mutex lock_;
 };
 
 }  // namespace unwindstack
diff --git a/libunwindstack/include/unwindstack/MapInfo.h b/libunwindstack/include/unwindstack/MapInfo.h
index ff634f26e9..9c6b55211c 100644
--- a/libunwindstack/include/unwindstack/MapInfo.h
+++ b/libunwindstack/include/unwindstack/MapInfo.h
@@ -72,7 +72,7 @@ struct MapInfo {
   std::atomic_uint64_t load_bias;
 
   // This function guarantees it will never return nullptr.
-  Elf* GetElf(const std::shared_ptr<Memory>& process_memory);
+  Elf* GetElf(const std::shared_ptr<Memory>& process_memory, ArchEnum expected_arch);
 
   uint64_t GetLoadBias(const std::shared_ptr<Memory>& process_memory);