unpacker.patch

From ded8d6105317394b8a011c85a0739b9ec13a090a Mon Sep 17 00:00:00 2001
From: Slava Makkaveev
Date: Wed, 12 Jul 2017 10:48:03 +0300
Subject: [PATCH] Android packer unpacking patch

---
 runtime/dex_file.cc | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/runtime/dex_file.cc b/runtime/dex_file.cc
index 25d5ef4..0a00a76 100644
--- a/runtime/dex_file.cc
+++ b/runtime/dex_file.cc
@@ -26,6 +26,7 @@
 
 #include <memory>
 #include <sstream>
+#include <fstream>
 
 #include "art_field-inl.h"
 #include "art_method-inl.h"
@@ -63,6 +64,31 @@ static int OpenAndReadMagic(const char* filename, uint32_t* magic, std::string*
     *error_msg = StringPrintf("Unable to open '%s' : %s", filename, strerror(errno));
     return -1;
   }
+
+  //------------------------------------------------------------------
+  // DEX file unpacking
+  //------------------------------------------------------------------  
+  
+  struct stat st;
+  // let's limit processing file list
+  if (strstr(filename, "/data/data") != NULL) {
+    char* fn_out = new char[PATH_MAX];
+    strcpy(fn_out, filename);
+    strcat(fn_out, "__unpacked_dex");
+    
+    int fd_out = open(fn_out, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
+
+    if (!fstat(fd.get(), &st)) {
+      char* addr = (char*)mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd.get(), 0);
+      write(fd_out, addr, st.st_size);
+      munmap(addr, st.st_size);
+    }   
+
+    close(fd_out);
+    delete fn_out;
+  }
+  //------------------------------------------------------------------
+
   int n = TEMP_FAILURE_RETRY(read(fd.get(), magic, sizeof(*magic)));
   if (n != sizeof(*magic)) {
     *error_msg = StringPrintf("Failed to find magic in '%s'", filename);
@@ -412,6 +438,19 @@ DexFile::DexFile(const uint8_t* base, size_t size,
       find_class_def_misses_(0),
       class_def_index_(nullptr),
       oat_dex_file_(oat_dex_file) {
+
+  //------------------------------------------------------------------
+  // DEX file unpacking
+  //------------------------------------------------------------------
+
+  // let's limit processing file list
+  if (location.find("/data/data/") != std::string::npos) {
+    std::ofstream dst(location + "__unpacked_oat", std::ios::binary);
+    dst.write(reinterpret_cast<const char*>(base), size);
+    dst.close();
+  }
+  //------------------------------------------------------------------
+
   CHECK(begin_ != nullptr) << GetLocation();
   CHECK_GT(size_, 0U) << GetLocation();
 }
-- 
2.7.4