Avoid re-mapping dex file that's in local memory.
If the Dex file we're trying to examine is already within the unwinder's
address space, we don't need to load it from disk or copy it across
processes.
This avoids using up virtual address space to map in dex files, and
also should be a bit faster to read since it won't go out to the file.
Patch by Chris Sarbora
Test: Ran new unit tests.
Test: Ran 137-cfi art test.
Change-Id: I949457856f051cca11b9020e9da3a41bbf6e5c8e
diff --git a/libunwindstack/DexFile.cpp b/libunwindstack/DexFile.cpp
index bf63abf..8fc3d23 100644
--- a/libunwindstack/DexFile.cpp
+++ b/libunwindstack/DexFile.cpp
@@ -50,6 +50,22 @@
std::unique_ptr<DexFile> DexFile::Create(uint64_t dex_file_offset_in_memory, Memory* memory,
MapInfo* info) {
+ if (UNLIKELY(!HasDexSupport())) {
+ return nullptr;
+ }
+
+ size_t max_size = info->end - dex_file_offset_in_memory;
+ if (memory->IsLocal()) {
+ size_t size = max_size;
+
+ std::string err_msg;
+ std::unique_ptr<art_api::dex::DexFile> art_dex_file = DexFile::OpenFromMemory(
+ reinterpret_cast<void const*>(dex_file_offset_in_memory), &size, info->name, &err_msg);
+ if (art_dex_file != nullptr && size <= max_size) {
+ return std::unique_ptr<DexFile>(new DexFile(art_dex_file));
+ }
+ }
+
if (!info->name.empty()) {
std::unique_ptr<DexFile> dex_file =
DexFileFromFile::Create(dex_file_offset_in_memory - info->start + info->offset, info->name);
@@ -57,7 +73,7 @@
return dex_file;
}
}
- return DexFileFromMemory::Create(dex_file_offset_in_memory, memory, info->name);
+ return DexFileFromMemory::Create(dex_file_offset_in_memory, memory, info->name, max_size);
}
bool DexFile::GetMethodInformation(uint64_t dex_offset, std::string* method_name,
@@ -94,7 +110,8 @@
std::unique_ptr<DexFileFromMemory> DexFileFromMemory::Create(uint64_t dex_file_offset_in_memory,
Memory* memory,
- const std::string& name) {
+ const std::string& name,
+ size_t max_size) {
if (UNLIKELY(!HasDexSupport())) {
return nullptr;
}
@@ -105,6 +122,9 @@
std::string error_msg;
std::unique_ptr<art_api::dex::DexFile> art_dex_file =
OpenFromMemory(backing_memory.data(), &size, name, &error_msg);
+ if (size > max_size) {
+ return nullptr;
+ }
if (art_dex_file != nullptr) {
return std::unique_ptr<DexFileFromMemory>(