ART: Do not relocate app program headers in patchoat.

Change the check whether to relocate program headers in
patchoat to simply look whether there is a PT_LOAD section
with p_vaddr == 0. If there is, don't relocate the headers,
it should be an app. Otherwise, it's a boot image and needs
to be relocated.

Add overflow checking to ElfFileImpl<>::GetLoadedSize().

Bug: 21047854

(cherry picked from commit 3fc9903407c6e89ffbbc92ded9e272d9de58e9b6)

Change-Id: Ib3e1295fc06993bcfbaadd8f253ee4f5498f52e9

3 files changed, 10 insertions, 9 deletions

diff --git a/compiler/elf_writer.cc b/compiler/elf_writer.cc
index 47402f3..f75638d 100644
--- a/compiler/elf_writer.cc
+++ b/compiler/elf_writer.cc
@@ -39,16 +39,17 @@ uintptr_t ElfWriter::GetOatDataAddress(ElfFile* elf_file) {
 }
 
 void ElfWriter::GetOatElfInformation(File* file,
-                                     size_t& oat_loaded_size,
-                                     size_t& oat_data_offset) {
+                                     size_t* oat_loaded_size,
+                                     size_t* oat_data_offset) {
   std::string error_msg;
   std::unique_ptr<ElfFile> elf_file(ElfFile::Open(file, false, false, &error_msg));
   CHECK(elf_file.get() != nullptr) << error_msg;
 
-  oat_loaded_size = elf_file->GetLoadedSize();
-  CHECK_NE(0U, oat_loaded_size);
-  oat_data_offset = GetOatDataAddress(elf_file.get());
-  CHECK_NE(0U, oat_data_offset);
+  bool success = elf_file->GetLoadedSize(oat_loaded_size, &error_msg);
+  CHECK(success) << error_msg;
+  CHECK_NE(0U, *oat_loaded_size);
+  *oat_data_offset = GetOatDataAddress(elf_file.get());
+  CHECK_NE(0U, *oat_data_offset);
 }
 
 bool ElfWriter::Fixup(File* file, uintptr_t oat_data_begin) {
diff --git a/compiler/elf_writer.h b/compiler/elf_writer.h
index 033c1f8..8e13b51 100644
--- a/compiler/elf_writer.h
+++ b/compiler/elf_writer.h
@@ -38,8 +38,8 @@ class ElfWriter {
   // Looks up information about location of oat file in elf file container.
   // Used for ImageWriter to perform memory layout.
   static void GetOatElfInformation(File* file,
-                                   size_t& oat_loaded_size,
-                                   size_t& oat_data_offset);
+                                   size_t* oat_loaded_size,
+                                   size_t* oat_data_offset);
 
   // Returns runtime oat_data runtime address for an opened ElfFile.
   static uintptr_t GetOatDataAddress(ElfFile* elf_file);
diff --git a/compiler/image_writer.cc b/compiler/image_writer.cc
index 4dc7509..195949b 100644
--- a/compiler/image_writer.cc
+++ b/compiler/image_writer.cc
@@ -166,7 +166,7 @@ bool ImageWriter::Write(const std::string& image_filename,
 
   size_t oat_loaded_size = 0;
   size_t oat_data_offset = 0;
-  ElfWriter::GetOatElfInformation(oat_file.get(), oat_loaded_size, oat_data_offset);
+  ElfWriter::GetOatElfInformation(oat_file.get(), &oat_loaded_size, &oat_data_offset);
 
   Thread::Current()->TransitionFromSuspendedToRunnable();
   CreateHeader(oat_loaded_size, oat_data_offset);