compiler-rt/lib/lsan/lsan_common.h

   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> &region);
 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