commit 7747b60faa5dcfd43d920c1e60abdab1150aab32
author Christopher Ferris <cferris@google.com> Wed Jan 31 19:05:19 2018 -0800
committer Christopher Ferris <cferris@google.com> Fri Feb 02 15:03:00 2018 -0800
tree 87d6249b19071be18cdb079980b09997369ada14
parent 4819edf4fc15264cae0d94fbda5482b2480e99b9

Load dex files from ART-specific data structure.

Fixes cdex which was recently changed to have shared data section,
which means the DEX PC cannot be used to find the right symbol,
as the bytecode is no longer within the dex file, and in-fact,
we might have to scan multiple dex files to find the method.

Bug: 72520014
Test: testrunner.py --host --cdex-none -t 137
Test: testrunner.py --host --cdex-fast -t 137
Test: All unit tests pass.
Change-Id: I80265d05ad69dd9cefbe3f8a75e4cd349002af5e

libunwindstack/DexFile.cpp

diff --git a/libunwindstack/DexFile.cpp b/libunwindstack/DexFile.cpp
index be6c2f7..b4a992a 100644
--- a/libunwindstack/DexFile.cpp
+++ b/libunwindstack/DexFile.cpp
@@ -52,10 +52,20 @@
   return nullptr;
 }
 
-void DexFile::GetMethodInformation(uint64_t dex_offset, std::string* method_name,
+DexFileFromFile::~DexFileFromFile() {
+  if (size_ != 0) {
+    munmap(mapped_memory_, size_);
+  }
+}
+
+bool DexFile::GetMethodInformation(uint64_t dex_offset, std::string* method_name,
                                    uint64_t* method_offset) {
   if (dex_file_ == nullptr) {
-    return;
+    return false;
+  }
+
+  if (!dex_file_->IsInDataSection(dex_file_->Begin() + dex_offset)) {
+    return false;  // The DEX offset is not within the bytecode of this dex file.
   }
 
   for (uint32_t i = 0; i < dex_file_->NumClassDefs(); ++i) {
@@ -82,16 +92,11 @@
       if (offset <= dex_offset && dex_offset < offset + size) {
         *method_name = dex_file_->PrettyMethod(it.GetMemberIndex(), false);
         *method_offset = dex_offset - offset;
-        return;
+        return true;
       }
     }
   }
-}
-
-DexFileFromFile::~DexFileFromFile() {
-  if (size_ != 0) {
-    munmap(mapped_memory_, size_);
-  }
+  return false;
 }
 
 bool DexFileFromFile::Open(uint64_t dex_file_offset_in_file, const std::string& file) {
@@ -139,25 +144,41 @@
 }
 
 bool DexFileFromMemory::Open(uint64_t dex_file_offset_in_memory, Memory* memory) {
-  art::DexFile::Header header;
-  if (!memory->ReadFully(dex_file_offset_in_memory, &header, sizeof(header))) {
+  memory_.resize(sizeof(art::DexFile::Header));
+  if (!memory->ReadFully(dex_file_offset_in_memory, memory_.data(), memory_.size())) {
     return false;
   }
 
-  if (!art::StandardDexFile::IsMagicValid(header.magic_) &&
-      !art::CompactDexFile::IsMagicValid(header.magic_)) {
+  art::DexFile::Header* header = reinterpret_cast<art::DexFile::Header*>(memory_.data());
+  bool modify_data_off = false;
+  uint32_t file_size = header->file_size_;
+  if (art::CompactDexFile::IsMagicValid(header->magic_)) {
+    uint32_t computed_file_size;
+    if (__builtin_add_overflow(header->data_off_, header->data_size_, &computed_file_size)) {
+      return false;
+    }
+    if (computed_file_size > file_size) {
+      file_size = computed_file_size;
+      modify_data_off = true;
+    }
+  } else if (!art::StandardDexFile::IsMagicValid(header->magic_)) {
     return false;
   }
 
-  memory_.resize(header.file_size_);
-  if (!memory->ReadFully(dex_file_offset_in_memory, memory_.data(), header.file_size_)) {
+  memory_.resize(file_size);
+  if (!memory->ReadFully(dex_file_offset_in_memory, memory_.data(), memory_.size())) {
     return false;
   }
 
+  header = reinterpret_cast<art::DexFile::Header*>(memory_.data());
+  if (modify_data_off) {
+    header->data_off_ = header->file_size_;
+  }
+
   art::DexFileLoader loader;
   std::string error_msg;
   auto dex =
-      loader.Open(memory_.data(), header.file_size_, "", 0, nullptr, false, false, &error_msg);
+      loader.Open(memory_.data(), header->file_size_, "", 0, nullptr, false, false, &error_msg);
   dex_file_.reset(dex.release());
   return dex_file_ != nullptr;
 }