Avoid recomputing the dex checksum during class loading
Thread the already computed checksum to VerifyOatAndDexFileChecksums and
LoadMultiDexFilesFromOatFile to avoid recomputing it.
Bug:17346103
(cherry picked from commit ca3459398018360d9968a52eebf727df085caf83)
Change-Id: Ie244efaca55b9e7c814b35feec7fce11fab3856d
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index ca97b08..1e64c00 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -785,7 +785,19 @@
return NULL;
}
-static bool LoadMultiDexFilesFromOatFile(const OatFile* oat_file, const char* dex_location,
+
+// Loads all multi dex files from the given oat file returning true on success.
+//
+// Parameters:
+// oat_file - the oat file to load from
+// dex_location - the dex location used to generate the oat file
+// dex_location_checksum - the checksum of the dex_location (may be null for pre-opted files)
+// generated - whether or not the oat_file existed before or was just (re)generated
+// error_msgs - any error messages will be appended here
+// dex_files - the loaded dex_files will be appended here (only if the loading succeeds)
+static bool LoadMultiDexFilesFromOatFile(const OatFile* oat_file,
+ const char* dex_location,
+ const uint32_t* dex_location_checksum,
bool generated,
std::vector<std::string>* error_msgs,
std::vector<const DexFile*>* dex_files) {
@@ -800,12 +812,20 @@
std::string next_name_str = DexFile::GetMultiDexClassesDexName(i, dex_location);
const char* next_name = next_name_str.c_str();
- uint32_t dex_location_checksum;
- uint32_t* dex_location_checksum_pointer = &dex_location_checksum;
+ uint32_t next_location_checksum;
+ uint32_t* next_location_checksum_pointer = &next_location_checksum;
std::string error_msg;
- if (!DexFile::GetChecksum(next_name, dex_location_checksum_pointer, &error_msg)) {
+ if ((i == 0) && (strcmp(next_name, dex_location) == 0)) {
+ // When i=0 the multidex name should be the same as the location name. We already have the
+ // checksum it so we don't need to recompute it.
+ if (dex_location_checksum == nullptr) {
+ next_location_checksum_pointer = nullptr;
+ } else {
+ next_location_checksum = *dex_location_checksum;
+ }
+ } else if (!DexFile::GetChecksum(next_name, next_location_checksum_pointer, &error_msg)) {
DCHECK_EQ(false, i == 0 && generated);
- dex_location_checksum_pointer = nullptr;
+ next_location_checksum_pointer = nullptr;
}
const OatFile::OatDexFile* oat_dex_file = oat_file->GetOatDexFile(next_name, nullptr, false);
@@ -814,7 +834,7 @@
if (i == 0 && generated) {
std::string error_msg;
error_msg = StringPrintf("\nFailed to find dex file '%s' (checksum 0x%x) in generated out "
- " file'%s'", dex_location, dex_location_checksum,
+ " file'%s'", dex_location, next_location_checksum,
oat_file->GetLocation().c_str());
error_msgs->push_back(error_msg);
}
@@ -823,8 +843,8 @@
// Checksum test. Test must succeed when generated.
success = !generated;
- if (dex_location_checksum_pointer != nullptr) {
- success = dex_location_checksum == oat_dex_file->GetDexFileLocationChecksum();
+ if (next_location_checksum_pointer != nullptr) {
+ success = next_location_checksum == oat_dex_file->GetDexFileLocationChecksum();
}
if (success) {
@@ -840,7 +860,7 @@
// When we generated the file, we expect success, or something is terribly wrong.
CHECK_EQ(false, generated && !success)
<< "dex_location=" << next_name << " oat_location=" << oat_file->GetLocation().c_str()
- << std::hex << " dex_location_checksum=" << dex_location_checksum
+ << std::hex << " dex_location_checksum=" << next_location_checksum
<< " OatDexFile::GetLocationChecksum()=" << oat_dex_file->GetDexFileLocationChecksum();
}
@@ -877,6 +897,7 @@
bool have_checksum = true;
std::string checksum_error_msg;
if (!DexFile::GetChecksum(dex_location, dex_location_checksum_pointer, &checksum_error_msg)) {
+ // This happens for pre-opted files since the corresponding dex files are no longer on disk.
dex_location_checksum_pointer = nullptr;
have_checksum = false;
}
@@ -942,8 +963,9 @@
// 3) If we have an oat file, check all contained multidex files for our dex_location.
// Note: LoadMultiDexFilesFromOatFile will check for nullptr in the first argument.
- bool success = LoadMultiDexFilesFromOatFile(open_oat_file.get(), dex_location, false, error_msgs,
- dex_files);
+ bool success = LoadMultiDexFilesFromOatFile(open_oat_file.get(), dex_location,
+ dex_location_checksum_pointer,
+ false, error_msgs, dex_files);
if (success) {
const OatFile* oat_file = open_oat_file.release(); // Avoid deleting it.
if (needs_registering) {
@@ -1004,8 +1026,8 @@
}
// Try to load again, but stronger checks.
- success = LoadMultiDexFilesFromOatFile(open_oat_file.get(), dex_location, true, error_msgs,
- dex_files);
+ success = LoadMultiDexFilesFromOatFile(open_oat_file.get(), dex_location, dex_location_checksum_pointer,
+ true, error_msgs, dex_files);
if (success) {
RegisterOatFile(open_oat_file.release());
return true;
@@ -1195,12 +1217,12 @@
bool ClassLinker::VerifyOatWithDexFile(const OatFile* oat_file,
const char* dex_location,
+ const uint32_t* dex_location_checksum,
std::string* error_msg) {
CHECK(oat_file != nullptr);
CHECK(dex_location != nullptr);
std::unique_ptr<const DexFile> dex_file;
- uint32_t dex_location_checksum;
- if (!DexFile::GetChecksum(dex_location, &dex_location_checksum, error_msg)) {
+ if (dex_location_checksum == nullptr) {
// If no classes.dex found in dex_location, it has been stripped or is corrupt, assume oat is
// up-to-date. This is the common case in user builds for jar's and apk's in the /system
// directory.
@@ -1213,13 +1235,13 @@
}
dex_file.reset(oat_dex_file->OpenDexFile(error_msg));
} else {
- bool verified = VerifyOatAndDexFileChecksums(oat_file, dex_location, dex_location_checksum,
+ bool verified = VerifyOatAndDexFileChecksums(oat_file, dex_location, *dex_location_checksum,
kRuntimeISA, error_msg);
if (!verified) {
return false;
}
dex_file.reset(oat_file->GetOatDexFile(dex_location,
- &dex_location_checksum)->OpenDexFile(error_msg));
+ dex_location_checksum)->OpenDexFile(error_msg));
}
return dex_file.get() != nullptr;
}
@@ -1243,7 +1265,8 @@
dex_location));
return nullptr;
} else if (oat_file->IsExecutable() &&
- !VerifyOatWithDexFile(oat_file.get(), dex_location, &error_msg)) {
+ !VerifyOatWithDexFile(oat_file.get(), dex_location,
+ dex_location_checksum, &error_msg)) {
error_msgs->push_back(StringPrintf("Failed to verify oat file '%s' found for dex location "
"'%s': %s", oat_file->GetLocation().c_str(), dex_location,
error_msg.c_str()));
diff --git a/runtime/class_linker.h b/runtime/class_linker.h
index 7750c8e..d1f5aa0 100644
--- a/runtime/class_linker.h
+++ b/runtime/class_linker.h
@@ -613,9 +613,18 @@
bool* obsolete_file_cleanup_failed)
LOCKS_EXCLUDED(dex_lock_, Locks::mutator_lock_);
- // verify an oat file with the given dex file. Will return false when the dex file could not be
- // verified. Will return true otherwise.
+ // Verifies:
+ // - that the oat file contains the dex file (with a matching checksum, which may be null if the
+ // file was pre-opted)
+ // - the checksums of the oat file (against the image space)
+ // - the checksum of the dex file against dex_location_checksum
+ // - that the dex file can be opened
+ // Returns true iff all verification succeed.
+ //
+ // The dex_location is the dex location as stored in the oat file header.
+ // (see DexFile::GetDexCanonicalLocation for a description of location conventions)
bool VerifyOatWithDexFile(const OatFile* oat_file, const char* dex_location,
+ const uint32_t* dex_location_checksum,
std::string* error_msg);
mirror::ArtMethod* CreateProxyConstructor(Thread* self, ConstHandle<mirror::Class> klass,
