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 void PrintThreads(); 115 116 //// -------------------------------------------------------------------------- 117 //// Allocator prototypes. 118 //// -------------------------------------------------------------------------- 119 120 // Wrappers for allocator's ForceLock()/ForceUnlock(). 121 void LockAllocator(); 122 void UnlockAllocator(); 123 124 // Lock/unlock global mutext. 125 void LockGlobal(); 126 void UnlockGlobal(); 127 128 // Returns the address range occupied by the global allocator object. 129 void GetAllocatorGlobalRange(uptr *begin, uptr *end); 130 // If p points into a chunk that has been allocated to the user, returns its 131 // user-visible address. Otherwise, returns 0. 132 uptr PointsIntoChunk(void *p); 133 // Returns address of user-visible chunk contained in this allocator chunk. 134 uptr GetUserBegin(uptr chunk); 135 // Returns user-visible address for chunk. If memory tagging is used this 136 // function will return the tagged address. 137 uptr GetUserAddr(uptr chunk); 138 139 // Wrapper for chunk metadata operations. 140 class LsanMetadata { 141 public: 142 // Constructor accepts address of user-visible chunk. 143 explicit LsanMetadata(uptr chunk); 144 bool allocated() const; 145 ChunkTag tag() const; 146 void set_tag(ChunkTag value); 147 uptr requested_size() const; 148 u32 stack_trace_id() const; 149 150 private: 151 void *metadata_; 152 }; 153 154 // Iterate over all existing chunks. Allocator must be locked. 155 void ForEachChunk(ForEachChunkCallback callback, void *arg); 156 157 // Helper for __lsan_ignore_object(). 158 IgnoreObjectResult IgnoreObject(const void *p); 159 160 // The rest of the LSan interface which is implemented by library. 161 162 struct ScopedStopTheWorldLock { 163 ScopedStopTheWorldLock() { 164 LockThreads(); 165 LockAllocator(); 166 } 167 168 ~ScopedStopTheWorldLock() { 169 UnlockAllocator(); 170 UnlockThreads(); 171 } 172 173 ScopedStopTheWorldLock &operator=(const ScopedStopTheWorldLock &) = delete; 174 ScopedStopTheWorldLock(const ScopedStopTheWorldLock &) = delete; 175 }; 176 177 struct Flags { 178 #define LSAN_FLAG(Type, Name, DefaultValue, Description) Type Name; 179 #include "lsan_flags.inc" 180 #undef LSAN_FLAG 181 182 void SetDefaults(); 183 uptr pointer_alignment() const { 184 return use_unaligned ? 1 : sizeof(uptr); 185 } 186 }; 187 188 extern Flags lsan_flags; 189 inline Flags *flags() { return &lsan_flags; } 190 void RegisterLsanFlags(FlagParser *parser, Flags *f); 191 192 struct LeakedChunk { 193 uptr chunk; 194 u32 stack_trace_id; 195 uptr leaked_size; 196 ChunkTag tag; 197 }; 198 199 using LeakedChunks = InternalMmapVector<LeakedChunk>; 200 201 struct Leak { 202 u32 id; 203 uptr hit_count; 204 uptr total_size; 205 u32 stack_trace_id; 206 bool is_directly_leaked; 207 bool is_suppressed; 208 }; 209 210 struct LeakedObject { 211 u32 leak_id; 212 uptr addr; 213 uptr size; 214 }; 215 216 // Aggregates leaks by stack trace prefix. 217 class LeakReport { 218 public: 219 LeakReport() {} 220 void AddLeakedChunks(const LeakedChunks &chunks); 221 void ReportTopLeaks(uptr max_leaks); 222 void PrintSummary(); 223 uptr ApplySuppressions(); 224 uptr UnsuppressedLeakCount(); 225 uptr IndirectUnsuppressedLeakCount(); 226 227 private: 228 void PrintReportForLeak(uptr index); 229 void PrintLeakedObjectsForLeak(uptr index); 230 231 u32 next_id_ = 0; 232 InternalMmapVector<Leak> leaks_; 233 InternalMmapVector<LeakedObject> leaked_objects_; 234 }; 235 236 typedef InternalMmapVector<uptr> Frontier; 237 238 // Platform-specific functions. 239 void InitializePlatformSpecificModules(); 240 void ProcessGlobalRegions(Frontier *frontier); 241 void ProcessPlatformSpecificAllocations(Frontier *frontier); 242 243 // LockStuffAndStopTheWorld can start to use Scan* calls to collect into 244 // this Frontier vector before the StopTheWorldCallback actually runs. 245 // This is used when the OS has a unified callback API for suspending 246 // threads and enumerating roots. 247 struct CheckForLeaksParam { 248 Frontier frontier; 249 LeakedChunks leaks; 250 tid_t caller_tid; 251 uptr caller_sp; 252 bool success = false; 253 }; 254 255 using Region = Range; 256 257 bool HasRootRegions(); 258 void ScanRootRegions(Frontier *frontier, 259 const InternalMmapVectorNoCtor<Region> ®ion); 260 // Run stoptheworld while holding any platform-specific locks, as well as the 261 // allocator and thread registry locks. 262 void LockStuffAndStopTheWorld(StopTheWorldCallback callback, 263 CheckForLeaksParam* argument); 264 265 void ScanRangeForPointers(uptr begin, uptr end, 266 Frontier *frontier, 267 const char *region_type, ChunkTag tag); 268 void ScanGlobalRange(uptr begin, uptr end, Frontier *frontier); 269 void ScanExtraStackRanges(const InternalMmapVector<Range> &ranges, 270 Frontier *frontier); 271 272 // Functions called from the parent tool. 273 const char *MaybeCallLsanDefaultOptions(); 274 void InitCommonLsan(); 275 void DoLeakCheck(); 276 void DoRecoverableLeakCheckVoid(); 277 void DisableCounterUnderflow(); 278 bool DisabledInThisThread(); 279 280 // Used to implement __lsan::ScopedDisabler. 281 void DisableInThisThread(); 282 void EnableInThisThread(); 283 // Can be used to ignore memory allocated by an intercepted 284 // function. 285 struct ScopedInterceptorDisabler { 286 ScopedInterceptorDisabler() { DisableInThisThread(); } 287 ~ScopedInterceptorDisabler() { EnableInThisThread(); } 288 }; 289 290 // According to Itanium C++ ABI array cookie is a one word containing 291 // size of allocated array. 292 static inline bool IsItaniumABIArrayCookie(uptr chunk_beg, uptr chunk_size, 293 uptr addr) { 294 return chunk_size == sizeof(uptr) && chunk_beg + chunk_size == addr && 295 *reinterpret_cast<uptr *>(chunk_beg) == 0; 296 } 297 298 // According to ARM C++ ABI array cookie consists of two words: 299 // struct array_cookie { 300 // std::size_t element_size; // element_size != 0 301 // std::size_t element_count; 302 // }; 303 static inline bool IsARMABIArrayCookie(uptr chunk_beg, uptr chunk_size, 304 uptr addr) { 305 return chunk_size == 2 * sizeof(uptr) && chunk_beg + chunk_size == addr && 306 *reinterpret_cast<uptr *>(chunk_beg + sizeof(uptr)) == 0; 307 } 308 309 // Special case for "new T[0]" where T is a type with DTOR. 310 // new T[0] will allocate a cookie (one or two words) for the array size (0) 311 // and store a pointer to the end of allocated chunk. The actual cookie layout 312 // varies between platforms according to their C++ ABI implementation. 313 inline bool IsSpecialCaseOfOperatorNew0(uptr chunk_beg, uptr chunk_size, 314 uptr addr) { 315 #if defined(__arm__) 316 return IsARMABIArrayCookie(chunk_beg, chunk_size, addr); 317 #else 318 return IsItaniumABIArrayCookie(chunk_beg, chunk_size, addr); 319 #endif 320 } 321 322 // Return the linker module, if valid for the platform. 323 LoadedModule *GetLinker(); 324 325 // Return true if LSan has finished leak checking and reported leaks. 326 bool HasReportedLeaks(); 327 328 // Run platform-specific leak handlers. 329 void HandleLeaks(); 330 331 } // namespace __lsan 332 333 extern "C" { 334 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE 335 const char *__lsan_default_options(); 336 337 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE 338 int __lsan_is_turned_off(); 339 340 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE 341 const char *__lsan_default_suppressions(); 342 343 SANITIZER_INTERFACE_ATTRIBUTE 344 void __lsan_register_root_region(const void *p, __lsan::uptr size); 345 346 SANITIZER_INTERFACE_ATTRIBUTE 347 void __lsan_unregister_root_region(const void *p, __lsan::uptr size); 348 349 } // extern "C" 350 351 #endif // LSAN_COMMON_H 352