1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "verification.h" 18 19 #include <iomanip> 20 #include <sstream> 21 22 #include "art_field-inl.h" 23 #include "base/file_utils.h" 24 #include "mirror/class-inl.h" 25 #include "mirror/object-refvisitor-inl.h" 26 27 namespace art { 28 namespace gc { 29 30 std::string Verification::DumpRAMAroundAddress(uintptr_t addr, uintptr_t bytes) const { 31 const uintptr_t dump_start = addr - bytes; 32 const uintptr_t dump_end = addr + bytes; 33 std::ostringstream oss; 34 if (dump_start < dump_end && 35 IsAddressInHeapSpace(reinterpret_cast<const void*>(dump_start)) && 36 IsAddressInHeapSpace(reinterpret_cast<const void*>(dump_end - 1))) { 37 oss << " adjacent_ram="; 38 for (uintptr_t p = dump_start; p < dump_end; ++p) { 39 if (p == addr) { 40 // Marker of where the address is. 41 oss << "|"; 42 } 43 uint8_t* ptr = reinterpret_cast<uint8_t*>(p); 44 oss << std::hex << std::setfill('0') << std::setw(2) << static_cast<uintptr_t>(*ptr); 45 } 46 } else { 47 oss << " <invalid address>"; 48 } 49 return oss.str(); 50 } 51 52 std::string Verification::DumpObjectInfo(const void* addr, const char* tag) const { 53 std::ostringstream oss; 54 oss << tag << "=" << addr; 55 if (IsValidHeapObjectAddress(addr)) { 56 mirror::Object* obj = reinterpret_cast<mirror::Object*>(const_cast<void*>(addr)); 57 mirror::Class* klass = obj->GetClass<kVerifyNone, kWithoutReadBarrier>(); 58 oss << " klass=" << klass; 59 if (IsValidClass(klass)) { 60 oss << "(" << klass->PrettyClass() << ")"; 61 if (klass->IsArrayClass<kVerifyNone, kWithoutReadBarrier>()) { 62 oss << " length=" << obj->AsArray<kVerifyNone, kWithoutReadBarrier>()->GetLength(); 63 } 64 } else { 65 oss << " <invalid address>"; 66 } 67 space::Space* const space = heap_->FindSpaceFromAddress(addr); 68 if (space != nullptr) { 69 oss << " space=" << *space; 70 } 71 accounting::CardTable* card_table = heap_->GetCardTable(); 72 if (card_table->AddrIsInCardTable(addr)) { 73 oss << " card=" << static_cast<size_t>( 74 card_table->GetCard(reinterpret_cast<const mirror::Object*>(addr))); 75 } 76 // Dump adjacent RAM. 77 oss << DumpRAMAroundAddress(reinterpret_cast<uintptr_t>(addr), 4 * kObjectAlignment); 78 } else { 79 oss << " <invalid address>"; 80 } 81 return oss.str(); 82 } 83 84 void Verification::LogHeapCorruption(ObjPtr<mirror::Object> holder, 85 MemberOffset offset, 86 mirror::Object* ref, 87 bool fatal) const { 88 // Lowest priority logging first: 89 PrintFileToLog("/proc/self/maps", android::base::LogSeverity::FATAL_WITHOUT_ABORT); 90 MemMap::DumpMaps(LOG_STREAM(FATAL_WITHOUT_ABORT), true); 91 // Buffer the output in the string stream since it is more important than the stack traces 92 // and we want it to have log priority. The stack traces are printed from Runtime::Abort 93 // which is called from LOG(FATAL) but before the abort message. 94 std::ostringstream oss; 95 oss << "GC tried to mark invalid reference " << ref << std::endl; 96 oss << DumpObjectInfo(ref, "ref") << "\n"; 97 oss << DumpObjectInfo(holder.Ptr(), "holder"); 98 if (holder != nullptr) { 99 mirror::Class* holder_klass = holder->GetClass<kVerifyNone, kWithoutReadBarrier>(); 100 if (IsValidClass(holder_klass)) { 101 oss << " field_offset=" << offset.Uint32Value(); 102 ArtField* field = holder->FindFieldByOffset(offset); 103 if (field != nullptr) { 104 oss << " name=" << field->GetName(); 105 } 106 } 107 mirror::HeapReference<mirror::Object>* addr = holder->GetFieldObjectReferenceAddr(offset); 108 oss << " reference addr" 109 << DumpRAMAroundAddress(reinterpret_cast<uintptr_t>(addr), 4 * kObjectAlignment); 110 } 111 112 if (fatal) { 113 LOG(FATAL) << oss.str(); 114 } else { 115 LOG(FATAL_WITHOUT_ABORT) << oss.str(); 116 } 117 } 118 119 bool Verification::IsAddressInHeapSpace(const void* addr, space::Space** out_space) const { 120 space::Space* const space = heap_->FindSpaceFromAddress(addr); 121 if (space != nullptr) { 122 if (out_space != nullptr) { 123 *out_space = space; 124 } 125 return true; 126 } 127 return false; 128 } 129 130 bool Verification::IsValidHeapObjectAddress(const void* addr, space::Space** out_space) const { 131 return IsAligned<kObjectAlignment>(addr) && IsAddressInHeapSpace(addr, out_space); 132 } 133 134 bool Verification::IsValidClass(const void* addr) const { 135 if (!IsValidHeapObjectAddress(addr)) { 136 return false; 137 } 138 mirror::Class* klass = reinterpret_cast<mirror::Class*>(const_cast<void*>(addr)); 139 mirror::Class* k1 = klass->GetClass<kVerifyNone, kWithoutReadBarrier>(); 140 if (!IsValidHeapObjectAddress(k1)) { 141 return false; 142 } 143 // `k1` should be class class, take the class again to verify. 144 // Note that this check may not be valid for the no image space since the class class might move 145 // around from moving GC. 146 mirror::Class* k2 = k1->GetClass<kVerifyNone, kWithoutReadBarrier>(); 147 if (!IsValidHeapObjectAddress(k2)) { 148 return false; 149 } 150 return k1 == k2; 151 } 152 153 using ObjectSet = std::set<mirror::Object*>; 154 using WorkQueue = std::deque<std::pair<mirror::Object*, std::string>>; 155 156 // Use for visiting the GcRoots held live by ArtFields, ArtMethods, and ClassLoaders. 157 class Verification::BFSFindReachable { 158 public: 159 explicit BFSFindReachable(ObjectSet* visited) : visited_(visited) {} 160 161 void operator()(mirror::Object* obj, MemberOffset offset, bool is_static ATTRIBUTE_UNUSED) const 162 REQUIRES_SHARED(Locks::mutator_lock_) { 163 ArtField* field = obj->FindFieldByOffset(offset); 164 Visit(obj->GetFieldObject<mirror::Object>(offset), 165 field != nullptr ? field->GetName() : ""); 166 } 167 168 void VisitRootIfNonNull(mirror::CompressedReference<mirror::Object>* root) const 169 REQUIRES_SHARED(Locks::mutator_lock_) { 170 if (!root->IsNull()) { 171 VisitRoot(root); 172 } 173 } 174 175 void VisitRoot(mirror::CompressedReference<mirror::Object>* root) const 176 REQUIRES_SHARED(Locks::mutator_lock_) { 177 Visit(root->AsMirrorPtr(), "!nativeRoot"); 178 } 179 180 void Visit(mirror::Object* ref, const std::string& field_name) const 181 REQUIRES_SHARED(Locks::mutator_lock_) { 182 if (ref != nullptr && visited_->insert(ref).second) { 183 new_visited_.emplace_back(ref, field_name); 184 } 185 } 186 187 const WorkQueue& NewlyVisited() const { 188 return new_visited_; 189 } 190 191 private: 192 ObjectSet* visited_; 193 mutable WorkQueue new_visited_; 194 }; 195 196 class Verification::CollectRootVisitor : public SingleRootVisitor { 197 public: 198 CollectRootVisitor(ObjectSet* visited, WorkQueue* work) : visited_(visited), work_(work) {} 199 200 void VisitRoot(mirror::Object* obj, const RootInfo& info) 201 OVERRIDE REQUIRES_SHARED(Locks::mutator_lock_) { 202 if (obj != nullptr && visited_->insert(obj).second) { 203 std::ostringstream oss; 204 oss << info.ToString() << " = " << obj << "(" << obj->PrettyTypeOf() << ")"; 205 work_->emplace_back(obj, oss.str()); 206 } 207 } 208 209 private: 210 ObjectSet* const visited_; 211 WorkQueue* const work_; 212 }; 213 214 std::string Verification::FirstPathFromRootSet(ObjPtr<mirror::Object> target) const { 215 Runtime* const runtime = Runtime::Current(); 216 std::set<mirror::Object*> visited; 217 std::deque<std::pair<mirror::Object*, std::string>> work; 218 { 219 CollectRootVisitor root_visitor(&visited, &work); 220 runtime->VisitRoots(&root_visitor, kVisitRootFlagAllRoots); 221 } 222 while (!work.empty()) { 223 auto pair = work.front(); 224 work.pop_front(); 225 if (pair.first == target) { 226 return pair.second; 227 } 228 BFSFindReachable visitor(&visited); 229 pair.first->VisitReferences(visitor, VoidFunctor()); 230 for (auto&& pair2 : visitor.NewlyVisited()) { 231 std::ostringstream oss; 232 mirror::Object* obj = pair2.first; 233 oss << pair.second << " -> " << obj << "(" << obj->PrettyTypeOf() << ")." << pair2.second; 234 work.emplace_back(obj, oss.str()); 235 } 236 } 237 return "<no path found>"; 238 } 239 240 } // namespace gc 241 } // namespace art 242
