Use canonical paths when searching for dex files
Apps which use the DexPathClassLoader directly may
pass symlinks when trying to load dex files. This
will not work as we use string comparision to find
the dex in an oat file. The CL fixes this issue by
using using dex conical paths for comparisons.
Bug: 15313272
Change-Id: Ic314374b17612c3afbcadec93a88b2515a0aca5e
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 12b7680..99907e3 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -680,14 +680,6 @@
return NULL;
}
-static std::string GetMultiDexClassesDexName(size_t number, const char* dex_location) {
- if (number == 0) {
- return dex_location;
- } else {
- return StringPrintf("%s" kMultiDexSeparatorString "classes%zu.dex", dex_location, number + 1);
- }
-}
-
static bool LoadMultiDexFilesFromOatFile(const OatFile* oat_file, const char* dex_location,
bool generated,
std::vector<std::string>* error_msgs,
@@ -700,7 +692,7 @@
bool success = true;
for (size_t i = 0; success; ++i) {
- std::string next_name_str = GetMultiDexClassesDexName(i, dex_location);
+ std::string next_name_str = DexFile::GetMultiDexClassesDexName(i, dex_location);
const char* next_name = next_name_str.c_str();
uint32_t dex_location_checksum;
diff --git a/runtime/dex_file.cc b/runtime/dex_file.cc
index e5bc7c8..e1a7771 100644
--- a/runtime/dex_file.cc
+++ b/runtime/dex_file.cc
@@ -951,6 +951,38 @@
return std::make_pair(tmp, colon_ptr + 1);
}
+std::string DexFile::GetMultiDexClassesDexName(size_t number, const char* dex_location) {
+ if (number == 0) {
+ return dex_location;
+ } else {
+ return StringPrintf("%s" kMultiDexSeparatorString "classes%zu.dex", dex_location, number + 1);
+ }
+}
+
+std::string DexFile::GetDexCanonicalLocation(const char* dex_location) {
+ CHECK_NE(dex_location, static_cast<const char*>(nullptr));
+ char* path = nullptr;
+ if (!IsMultiDexLocation(dex_location)) {
+ path = realpath(dex_location, nullptr);
+ } else {
+ std::pair<const char*, const char*> pair = DexFile::SplitMultiDexLocation(dex_location);
+ const char* dex_real_location(realpath(pair.first, nullptr));
+ delete pair.first;
+ if (dex_real_location != nullptr) {
+ int length = strlen(dex_real_location) + strlen(pair.second) + strlen(kMultiDexSeparatorString) + 1;
+ char* multidex_canonical_location = reinterpret_cast<char*>(malloc(sizeof(char) * length));
+ snprintf(multidex_canonical_location, length, "%s" kMultiDexSeparatorString "%s", dex_real_location, pair.second);
+ free(const_cast<char*>(dex_real_location));
+ path = multidex_canonical_location;
+ }
+ }
+
+ // If realpath fails then we just copy the argument.
+ std::string result(path == nullptr ? dex_location : path);
+ free(path);
+ return result;
+}
+
std::ostream& operator<<(std::ostream& os, const DexFile& dex_file) {
os << StringPrintf("[DexFile: %s dex-checksum=%08x location-checksum=%08x %p-%p]",
dex_file.GetLocation().c_str(),
@@ -958,6 +990,7 @@
dex_file.Begin(), dex_file.Begin() + dex_file.Size());
return os;
}
+
std::string Signature::ToString() const {
if (dex_file_ == nullptr) {
CHECK(proto_id_ == nullptr);
diff --git a/runtime/dex_file.h b/runtime/dex_file.h
index d64a030..2794af6 100644
--- a/runtime/dex_file.h
+++ b/runtime/dex_file.h
@@ -841,6 +841,23 @@
return size_;
}
+ static std::string GetMultiDexClassesDexName(size_t number, const char* dex_location);
+
+ // Returns the canonical form of the given dex location.
+ //
+ // There are different flavors of "dex locations" as follows:
+ // the file name of a dex file:
+ // The actual file path that the dex file has on disk.
+ // dex_location:
+ // This acts as a key for the class linker to know which dex file to load.
+ // It may correspond to either an old odex file or a particular dex file
+ // inside an oat file. In the first case it will also match the file name
+ // of the dex file. In the second case (oat) it will include the file name
+ // and possibly some multidex annotation to uniquely identify it.
+ // canonical_dex_location:
+ // the dex_location where it's file name part has been made canonical.
+ static std::string GetDexCanonicalLocation(const char* dex_location);
+
private:
// Opens a .dex file
static const DexFile* OpenFile(int fd, const char* location, bool verify, std::string* error_msg);
diff --git a/runtime/dex_file_test.cc b/runtime/dex_file_test.cc
index 284aa89..fa13290 100644
--- a/runtime/dex_file_test.cc
+++ b/runtime/dex_file_test.cc
@@ -345,4 +345,31 @@
}
}
+TEST_F(DexFileTest, GetMultiDexClassesDexName) {
+ std::string dex_location_str = "/system/app/framework.jar";
+ const char* dex_location = dex_location_str.c_str();
+ ASSERT_EQ("/system/app/framework.jar", DexFile::GetMultiDexClassesDexName(0, dex_location));
+ ASSERT_EQ("/system/app/framework.jar:classes2.dex", DexFile::GetMultiDexClassesDexName(1, dex_location));
+ ASSERT_EQ("/system/app/framework.jar:classes101.dex", DexFile::GetMultiDexClassesDexName(100, dex_location));
+}
+
+TEST_F(DexFileTest, GetDexCanonicalLocation) {
+ ScratchFile file;
+ std::string dex_location = file.GetFilename();
+
+ ASSERT_EQ(file.GetFilename(), DexFile::GetDexCanonicalLocation(dex_location.c_str()));
+ std::string multidex_location = DexFile::GetMultiDexClassesDexName(1, dex_location.c_str());
+ ASSERT_EQ(multidex_location, DexFile::GetDexCanonicalLocation(multidex_location.c_str()));
+
+ std::string dex_location_sym = dex_location + "symlink";
+ ASSERT_EQ(0, symlink(dex_location.c_str(), dex_location_sym.c_str()));
+
+ ASSERT_EQ(dex_location, DexFile::GetDexCanonicalLocation(dex_location_sym.c_str()));
+
+ std::string multidex_location_sym = DexFile::GetMultiDexClassesDexName(1, dex_location_sym.c_str());
+ ASSERT_EQ(multidex_location, DexFile::GetDexCanonicalLocation(multidex_location_sym.c_str()));
+
+ ASSERT_EQ(0, unlink(dex_location_sym.c_str()));
+}
+
} // namespace art
diff --git a/runtime/oat_file.cc b/runtime/oat_file.cc
index f9cc36a..c4c6b10 100644
--- a/runtime/oat_file.cc
+++ b/runtime/oat_file.cc
@@ -18,6 +18,7 @@
#include <dlfcn.h>
#include <sstream>
+#include <string.h>
#include "base/bit_vector.h"
#include "base/stl_util.h"
@@ -125,6 +126,9 @@
}
OatFile::~OatFile() {
+ for (auto it : oat_dex_files_) {
+ delete it.first.data();
+ }
STLDeleteValues(&oat_dex_files_);
if (dlopen_handle_ != NULL) {
dlclose(dlopen_handle_);
@@ -305,8 +309,14 @@
dex_file_checksum,
dex_file_pointer,
methods_offsets_pointer);
- // Use a StringPiece backed by the oat_dex_file's internal std::string as the key.
- StringPiece key(oat_dex_file->GetDexFileLocation());
+
+ std::string dex_canonical_location_str = DexFile::GetDexCanonicalLocation(dex_file_location.c_str());
+ // make a copy since we need to persist it as a key in the object's field.
+ int location_size = dex_canonical_location_str.size() + 1;
+ char* dex_canonical_location = new char[location_size ];
+ strncpy(dex_canonical_location, dex_canonical_location_str.c_str(), location_size);
+
+ StringPiece key(dex_canonical_location);
oat_dex_files_.Put(key, oat_dex_file);
}
return true;
@@ -329,7 +339,9 @@
const OatFile::OatDexFile* OatFile::GetOatDexFile(const char* dex_location,
const uint32_t* dex_location_checksum,
bool warn_if_not_found) const {
- Table::const_iterator it = oat_dex_files_.find(dex_location);
+ std::string dex_canonical_location = DexFile::GetDexCanonicalLocation(dex_location);
+
+ Table::const_iterator it = oat_dex_files_.find(dex_canonical_location);
if (it != oat_dex_files_.end()) {
const OatFile::OatDexFile* oat_dex_file = it->second;
if (dex_location_checksum == NULL ||
@@ -344,15 +356,18 @@
checksum = StringPrintf("0x%08x", *dex_location_checksum);
}
LOG(WARNING) << "Failed to find OatDexFile for DexFile " << dex_location
+ << " ( canonical path " << dex_canonical_location << ")"
<< " with checksum " << checksum << " in OatFile " << GetLocation();
if (kIsDebugBuild) {
for (Table::const_iterator it = oat_dex_files_.begin(); it != oat_dex_files_.end(); ++it) {
LOG(WARNING) << "OatFile " << GetLocation()
<< " contains OatDexFile " << it->second->GetDexFileLocation()
+ << " (canonical path " << it->first << ")"
<< " with checksum 0x" << std::hex << it->second->GetDexFileLocationChecksum();
}
}
}
+
return NULL;
}