1 //=-- lsan_common.h -------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of LeakSanitizer. 10 // Private LSan header. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LSAN_COMMON_H 15 #define LSAN_COMMON_H 16 17 #include "sanitizer_common/sanitizer_allocator.h" 18 #include "sanitizer_common/sanitizer_common.h" 19 #include "sanitizer_common/sanitizer_internal_defs.h" 20 #include "sanitizer_common/sanitizer_platform.h" 21 #include "sanitizer_common/sanitizer_range.h" 22 #include "sanitizer_common/sanitizer_stackdepot.h" 23 #include "sanitizer_common/sanitizer_stoptheworld.h" 24 #include "sanitizer_common/sanitizer_symbolizer.h" 25 #include "sanitizer_common/sanitizer_thread_registry.h" 26 27 // LeakSanitizer relies on some Glibc's internals (e.g. TLS machinery) on Linux. 28 // Also, LSan doesn't like 32 bit architectures 29 // because of "small" (4 bytes) pointer size that leads to high false negative 30 // ratio on large leaks. But we still want to have it for some 32 bit arches 31 // (e.g. x86), see https://github.com/google/sanitizers/issues/403. 32 // To enable LeakSanitizer on a new architecture, one needs to implement the 33 // internal_clone function as well as (probably) adjust the TLS machinery for 34 // the new architecture inside the sanitizer library. 35 // Exclude leak-detection on arm32 for Android because `__aeabi_read_tp` 36 // is missing. This caused a link error. 37 #if SANITIZER_ANDROID && (__ANDROID_API__ < 28 || defined(__arm__)) 38 # define CAN_SANITIZE_LEAKS 0 39 #elif (SANITIZER_LINUX || SANITIZER_APPLE) && (SANITIZER_WORDSIZE == 64) && \ 40 (defined(__x86_64__) || defined(__mips64) || defined(__aarch64__) || \ 41 defined(__powerpc64__) || defined(__s390x__)) 42 # define CAN_SANITIZE_LEAKS 1 43 #elif defined(__i386__) && (SANITIZER_LINUX || SANITIZER_APPLE) 44 # define CAN_SANITIZE_LEAKS 1 45 #elif defined(__arm__) && SANITIZER_LINUX 46 # define CAN_SANITIZE_LEAKS 1 47 #elif SANITIZER_LOONGARCH64 && SANITIZER_LINUX 48 # define CAN_SANITIZE_LEAKS 1 49 #elif SANITIZER_RISCV64 && SANITIZER_LINUX 50 # define CAN_SANITIZE_LEAKS 1 51 #elif SANITIZER_NETBSD || SANITIZER_FUCHSIA 52 # define CAN_SANITIZE_LEAKS 1 53 #else 54 # define CAN_SANITIZE_LEAKS 0 55 #endif 56 57 namespace __sanitizer { 58 class FlagParser; 59 class ThreadRegistry; 60 class ThreadContextBase; 61 struct DTLS; 62 } 63 64 // This section defines function and class prototypes which must be implemented 65 // by the parent tool linking in LSan. There are implementations provided by the 66 // LSan library which will be linked in when LSan is used as a standalone tool. 67 namespace __lsan { 68 69 // Chunk tags. 70 enum ChunkTag { 71 kDirectlyLeaked = 0, // default 72 kIndirectlyLeaked = 1, 73 kReachable = 2, 74 kIgnored = 3 75 }; 76 77 enum IgnoreObjectResult { 78 kIgnoreObjectSuccess, 79 kIgnoreObjectAlreadyIgnored, 80 kIgnoreObjectInvalid 81 }; 82 83 //// -------------------------------------------------------------------------- 84 //// Poisoning prototypes. 85 //// -------------------------------------------------------------------------- 86 87 // Returns true if [addr, addr + sizeof(void *)) is poisoned. 88 bool WordIsPoisoned(uptr addr); 89 90 //// -------------------------------------------------------------------------- 91 //// Thread prototypes. 92 //// -------------------------------------------------------------------------- 93 94 // Wrappers for ThreadRegistry access. 95 void LockThreads() SANITIZER_NO_THREAD_SAFETY_ANALYSIS; 96 void UnlockThreads() SANITIZER_NO_THREAD_SAFETY_ANALYSIS; 97 // If called from the main thread, updates the main thread's TID in the thread 98 // registry. We need this to handle processes that fork() without a subsequent 99 // exec(), which invalidates the recorded TID. To update it, we must call 100 // gettid() from the main thread. Our solution is to call this function before 101 // leak checking and also before every call to pthread_create() (to handle cases 102 // where leak checking is initiated from a non-main thread). 103 void EnsureMainThreadIDIsCorrect(); 104 105 bool GetThreadRangesLocked(tid_t os_id, uptr *stack_begin, uptr *stack_end, 106 uptr *tls_begin, uptr *tls_end, uptr *cache_begin, 107 uptr *cache_end, DTLS **dtls); 108 void GetAllThreadAllocatorCachesLocked(InternalMmapVector<uptr> *caches); 109 void GetThreadExtraStackRangesLocked(InternalMmapVector<Range> *ranges); 110 void GetThreadExtraStackRangesLocked(tid_t os_id, 111 InternalMmapVector<Range> *ranges); 112 void GetAdditionalThreadContextPtrsLocked(InternalMmapVector<uptr> *ptrs); 113 void GetRunningThreadsLocked(InternalMmapVector<tid_t> *threads); 114 115 //// -------------------------------------------------------------------------- 116 //// Allocator prototypes. 117 //// -------------------------------------------------------------------------- 118 119 // Wrappers for allocator's ForceLock()/ForceUnlock(). 120 void LockAllocator(); 121 void UnlockAllocator(); 122 123 // Lock/unlock global mutext. 124 void LockGlobal(); 125 void UnlockGlobal(); 126 127 // Returns the address range occupied by the global allocator object. 128 void GetAllocatorGlobalRange(uptr *begin, uptr *end); 129 // If p points into a chunk that has been allocated to the user, returns its 130 // user-visible address. Otherwise, returns 0. 131 uptr PointsIntoChunk(void *p); 132 // Returns address of user-visible chunk contained in this allocator chunk. 133 uptr GetUserBegin(uptr chunk); 134 // Returns user-visible address for chunk. If memory tagging is used this 135 // function will return the tagged address. 136 uptr GetUserAddr(uptr chunk); 137 138 // Wrapper for chunk metadata operations. 139 class LsanMetadata { 140 public: 141 // Constructor accepts address of user-visible chunk. 142 explicit LsanMetadata(uptr chunk); 143 bool allocated() const; 144 ChunkTag tag() const; 145 void set_tag(ChunkTag value); 146 uptr requested_size() const; 147 u32 stack_trace_id() const; 148 149 private: 150 void *metadata_; 151 }; 152 153 // Iterate over all existing chunks. Allocator must be locked. 154 void ForEachChunk(ForEachChunkCallback callback, void *arg); 155 156 // Helper for __lsan_ignore_object(). 157 IgnoreObjectResult IgnoreObject(const void *p); 158 159 // The rest of the LSan interface which is implemented by library. 160 161 struct ScopedStopTheWorldLock { 162 ScopedStopTheWorldLock() { 163 LockThreads(); 164 LockAllocator(); 165 } 166 167 ~ScopedStopTheWorldLock() { 168 UnlockAllocator(); 169 UnlockThreads(); 170 } 171 172 ScopedStopTheWorldLock &operator=(const ScopedStopTheWorldLock &) = delete; 173 ScopedStopTheWorldLock(const ScopedStopTheWorldLock &) = delete; 174 }; 175 176 struct Flags { 177 #define LSAN_FLAG(Type, Name, DefaultValue, Description) Type Name; 178 #include "lsan_flags.inc" 179 #undef LSAN_FLAG 180 181 void SetDefaults(); 182 uptr pointer_alignment() const { 183 return use_unaligned ? 1 : sizeof(uptr); 184 } 185 }; 186 187 extern Flags lsan_flags; 188 inline Flags *flags() { return &lsan_flags; } 189 void RegisterLsanFlags(FlagParser *parser, Flags *f); 190 191 struct LeakedChunk { 192 uptr chunk; 193 u32 stack_trace_id; 194 uptr leaked_size; 195 ChunkTag tag; 196 }; 197 198 using LeakedChunks = InternalMmapVector<LeakedChunk>; 199 200 struct Leak { 201 u32 id; 202 uptr hit_count; 203 uptr total_size; 204 u32 stack_trace_id; 205 bool is_directly_leaked; 206 bool is_suppressed; 207 }; 208 209 struct LeakedObject { 210 u32 leak_id; 211 uptr addr; 212 uptr size; 213 }; 214 215 // Aggregates leaks by stack trace prefix. 216 class LeakReport { 217 public: 218 LeakReport() {} 219 void AddLeakedChunks(const LeakedChunks &chunks); 220 void ReportTopLeaks(uptr max_leaks); 221 void PrintSummary(); 222 uptr ApplySuppressions(); 223 uptr UnsuppressedLeakCount(); 224 uptr IndirectUnsuppressedLeakCount(); 225 226 private: 227 void PrintReportForLeak(uptr index); 228 void PrintLeakedObjectsForLeak(uptr index); 229 230 u32 next_id_ = 0; 231 InternalMmapVector<Leak> leaks_; 232 InternalMmapVector<LeakedObject> leaked_objects_; 233 }; 234 235 typedef InternalMmapVector<uptr> Frontier; 236 237 // Platform-specific functions. 238 void InitializePlatformSpecificModules(); 239 void ProcessGlobalRegions(Frontier *frontier); 240 void ProcessPlatformSpecificAllocations(Frontier *frontier); 241 242 // LockStuffAndStopTheWorld can start to use Scan* calls to collect into 243 // this Frontier vector before the StopTheWorldCallback actually runs. 244 // This is used when the OS has a unified callback API for suspending 245 // threads and enumerating roots. 246 struct CheckForLeaksParam { 247 Frontier frontier; 248 LeakedChunks leaks; 249 tid_t caller_tid; 250 uptr caller_sp; 251 bool success = false; 252 }; 253 254 using Region = Range; 255 256 bool HasRootRegions(); 257 void ScanRootRegions(Frontier *frontier, 258 const InternalMmapVectorNoCtor<Region> ®ion); 259 // Run stoptheworld while holding any platform-specific locks, as well as the 260 // allocator and thread registry locks. 261 void LockStuffAndStopTheWorld(StopTheWorldCallback callback, 262 CheckForLeaksParam* argument); 263 264 void ScanRangeForPointers(uptr begin, uptr end, 265 Frontier *frontier, 266 const char *region_type, ChunkTag tag); 267 void ScanGlobalRange(uptr begin, uptr end, Frontier *frontier); 268 void ScanExtraStackRanges(const InternalMmapVector<Range> &ranges, 269 Frontier *frontier); 270 271 // Functions called from the parent tool. 272 const char *MaybeCallLsanDefaultOptions(); 273 void InitCommonLsan(); 274 void DoLeakCheck(); 275 void DoRecoverableLeakCheckVoid(); 276 void DisableCounterUnderflow(); 277 bool DisabledInThisThread(); 278 279 // Used to implement __lsan::ScopedDisabler. 280 void DisableInThisThread(); 281 void EnableInThisThread(); 282 // Can be used to ignore memory allocated by an intercepted 283 // function. 284 struct ScopedInterceptorDisabler { 285 ScopedInterceptorDisabler() { DisableInThisThread(); } 286 ~ScopedInterceptorDisabler() { EnableInThisThread(); } 287 }; 288 289 // According to Itanium C++ ABI array cookie is a one word containing 290 // size of allocated array. 291 static inline bool IsItaniumABIArrayCookie(uptr chunk_beg, uptr chunk_size, 292 uptr addr) { 293 return chunk_size == sizeof(uptr) && chunk_beg + chunk_size == addr && 294 *reinterpret_cast<uptr *>(chunk_beg) == 0; 295 } 296 297 // According to ARM C++ ABI array cookie consists of two words: 298 // struct array_cookie { 299 // std::size_t element_size; // element_size != 0 300 // std::size_t element_count; 301 // }; 302 static inline bool IsARMABIArrayCookie(uptr chunk_beg, uptr chunk_size, 303 uptr addr) { 304 return chunk_size == 2 * sizeof(uptr) && chunk_beg + chunk_size == addr && 305 *reinterpret_cast<uptr *>(chunk_beg + sizeof(uptr)) == 0; 306 } 307 308 // Special case for "new T[0]" where T is a type with DTOR. 309 // new T[0] will allocate a cookie (one or two words) for the array size (0) 310 // and store a pointer to the end of allocated chunk. The actual cookie layout 311 // varies between platforms according to their C++ ABI implementation. 312 inline bool IsSpecialCaseOfOperatorNew0(uptr chunk_beg, uptr chunk_size, 313 uptr addr) { 314 #if defined(__arm__) 315 return IsARMABIArrayCookie(chunk_beg, chunk_size, addr); 316 #else 317 return IsItaniumABIArrayCookie(chunk_beg, chunk_size, addr); 318 #endif 319 } 320 321 // Return the linker module, if valid for the platform. 322 LoadedModule *GetLinker(); 323 324 // Return true if LSan has finished leak checking and reported leaks. 325 bool HasReportedLeaks(); 326 327 // Run platform-specific leak handlers. 328 void HandleLeaks(); 329 330 } // namespace __lsan 331 332 extern "C" { 333 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE 334 const char *__lsan_default_options(); 335 336 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE 337 int __lsan_is_turned_off(); 338 339 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE 340 const char *__lsan_default_suppressions(); 341 342 SANITIZER_INTERFACE_ATTRIBUTE 343 void __lsan_register_root_region(const void *p, __lsan::uptr size); 344 345 SANITIZER_INTERFACE_ATTRIBUTE 346 void __lsan_unregister_root_region(const void *p, __lsan::uptr size); 347 348 } // extern "C" 349 350 #endif // LSAN_COMMON_H 351