Get a basic modification of dex file working
This allows the modification of a single classes methods through
transformation. One must ensure that the provided dex file only
contains one function and does not add or remove any methods or fields
and does not change the inheritance hierarchy in any way. The provided
dex file must verify and there must be no frames of the old code
present on any thread. These constraints are not checked or verified.
Breaking them might cause undefined behavior in all parts of the
runtime. Code that has been inlined in any way might not be replaced.
This feature is extremely experimental.
Bug: 31455788
Test: ./test/run-test --host 902-hello-transformation
Change-Id: I35133d24f6cdafdd2af9dc9863e15ba8493fc50e
diff --git a/runtime/dex_file_verifier_test.cc b/runtime/dex_file_verifier_test.cc
index 5939ef3..c5a4d75 100644
--- a/runtime/dex_file_verifier_test.cc
+++ b/runtime/dex_file_verifier_test.cc
@@ -29,34 +29,10 @@
#include "leb128.h"
#include "scoped_thread_state_change.h"
#include "thread-inl.h"
+#include "utils.h"
namespace art {
-static const uint8_t kBase64Map[256] = {
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 62, 255, 255, 255, 63,
- 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 255, 255,
- 255, 254, 255, 255, 255, 0, 1, 2, 3, 4, 5, 6,
- 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, // NOLINT
- 19, 20, 21, 22, 23, 24, 25, 255, 255, 255, 255, 255, // NOLINT
- 255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36,
- 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, // NOLINT
- 49, 50, 51, 255, 255, 255, 255, 255, 255, 255, 255, 255, // NOLINT
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
- 255, 255, 255, 255
-};
-
// Make the Dex file version 37.
static void MakeDexVersion37(DexFile* dex_file) {
size_t offset = OFFSETOF_MEMBER(DexFile::Header, magic_) + 6;
@@ -64,52 +40,6 @@
*(const_cast<uint8_t*>(dex_file->Begin()) + offset) = '7';
}
-static inline std::unique_ptr<uint8_t[]> DecodeBase64(const char* src, size_t* dst_size) {
- std::vector<uint8_t> tmp;
- uint32_t t = 0, y = 0;
- int g = 3;
- for (size_t i = 0; src[i] != '\0'; ++i) {
- uint8_t c = kBase64Map[src[i] & 0xFF];
- if (c == 255) continue;
- // the final = symbols are read and used to trim the remaining bytes
- if (c == 254) {
- c = 0;
- // prevent g < 0 which would potentially allow an overflow later
- if (--g < 0) {
- *dst_size = 0;
- return nullptr;
- }
- } else if (g != 3) {
- // we only allow = to be at the end
- *dst_size = 0;
- return nullptr;
- }
- t = (t << 6) | c;
- if (++y == 4) {
- tmp.push_back((t >> 16) & 255);
- if (g > 1) {
- tmp.push_back((t >> 8) & 255);
- }
- if (g > 2) {
- tmp.push_back(t & 255);
- }
- y = t = 0;
- }
- }
- if (y != 0) {
- *dst_size = 0;
- return nullptr;
- }
- std::unique_ptr<uint8_t[]> dst(new uint8_t[tmp.size()]);
- if (dst_size != nullptr) {
- *dst_size = tmp.size();
- } else {
- *dst_size = 0;
- }
- std::copy(tmp.begin(), tmp.end(), dst.get());
- return dst;
-}
-
static void FixUpChecksum(uint8_t* dex_file) {
DexFile::Header* header = reinterpret_cast<DexFile::Header*>(dex_file);
uint32_t expected_size = header->file_size_;
@@ -131,7 +61,7 @@
std::function<void(DexFile*)> f,
const char* expected_error) {
size_t length;
- std::unique_ptr<uint8_t[]> dex_bytes = DecodeBase64(dex_file_base64_content, &length);
+ std::unique_ptr<uint8_t[]> dex_bytes(DecodeBase64(dex_file_base64_content, &length));
CHECK(dex_bytes != nullptr);
// Note: `dex_file` will be destroyed before `dex_bytes`.
std::unique_ptr<DexFile> dex_file(GetDexFile(dex_bytes.get(), length));
@@ -1704,7 +1634,7 @@
TEST_F(DexFileVerifierTest, Checksum) {
size_t length;
- std::unique_ptr<uint8_t[]> dex_bytes = DecodeBase64(kGoodTestDex, &length);
+ std::unique_ptr<uint8_t[]> dex_bytes(DecodeBase64(kGoodTestDex, &length));
CHECK(dex_bytes != nullptr);
// Note: `dex_file` will be destroyed before `dex_bytes`.
std::unique_ptr<DexFile> dex_file(GetDexFile(dex_bytes.get(), length));