compiler-rt/lib/tsan/rtl/tsan_mman.cpp

   1 //===-- tsan_mman.cpp -----------------------------------------------------===//
   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 ThreadSanitizer (TSan), a race detector.
  10 //
  11 //===----------------------------------------------------------------------===//
  12 #include "sanitizer_common/sanitizer_allocator_checks.h"
  13 #include "sanitizer_common/sanitizer_allocator_interface.h"
  14 #include "sanitizer_common/sanitizer_allocator_report.h"
  15 #include "sanitizer_common/sanitizer_common.h"
  16 #include "sanitizer_common/sanitizer_errno.h"
  17 #include "sanitizer_common/sanitizer_placement_new.h"
  18 #include "tsan_mman.h"
  19 #include "tsan_rtl.h"
  20 #include "tsan_report.h"
  21 #include "tsan_flags.h"
  22
  23 // May be overriden by front-end.
  24 SANITIZER_WEAK_DEFAULT_IMPL
  25 void __sanitizer_malloc_hook(void *ptr, uptr size) {
  26   (void)ptr;
  27   (void)size;
  28 }
  29
  30 SANITIZER_WEAK_DEFAULT_IMPL
  31 void __sanitizer_free_hook(void *ptr) {
  32   (void)ptr;
  33 }
  34
  35 namespace __tsan {
  36
  37 struct MapUnmapCallback {
  38   void OnMap(uptr p, uptr size) const { }
  39   void OnUnmap(uptr p, uptr size) const {
  40     // We are about to unmap a chunk of user memory.
  41     // Mark the corresponding shadow memory as not needed.
  42     DontNeedShadowFor(p, size);
  43     // Mark the corresponding meta shadow memory as not needed.
  44     // Note the block does not contain any meta info at this point
  45     // (this happens after free).
  46     const uptr kMetaRatio = kMetaShadowCell / kMetaShadowSize;
  47     const uptr kPageSize = GetPageSizeCached() * kMetaRatio;
  48     // Block came from LargeMmapAllocator, so must be large.
  49     // We rely on this in the calculations below.
  50     CHECK_GE(size, 2 * kPageSize);
  51     uptr diff = RoundUp(p, kPageSize) - p;
  52     if (diff != 0) {
  53       p += diff;
  54       size -= diff;
  55     }
  56     diff = p + size - RoundDown(p + size, kPageSize);
  57     if (diff != 0)
  58       size -= diff;
  59     uptr p_meta = (uptr)MemToMeta(p);
  60     ReleaseMemoryPagesToOS(p_meta, p_meta + size / kMetaRatio);
  61   }
  62 };
  63
  64 static char allocator_placeholder[sizeof(Allocator)] ALIGNED(64);
  65 Allocator *allocator() {
  66   return reinterpret_cast<Allocator*>(&allocator_placeholder);
  67 }
  68
  69 struct GlobalProc {
  70   Mutex mtx;
  71   Processor *proc;
  72   // This mutex represents the internal allocator combined for
  73   // the purposes of deadlock detection. The internal allocator
  74   // uses multiple mutexes, moreover they are locked only occasionally
  75   // and they are spin mutexes which don't support deadlock detection.
  76   // So we use this fake mutex to serve as a substitute for these mutexes.
  77   CheckedMutex internal_alloc_mtx;
  78
  79   GlobalProc()
  80       : mtx(MutexTypeGlobalProc),
  81         proc(ProcCreate()),
  82         internal_alloc_mtx(MutexTypeInternalAlloc) {}
  83 };
  84
  85 static char global_proc_placeholder[sizeof(GlobalProc)] ALIGNED(64);
  86 GlobalProc *global_proc() {
  87   return reinterpret_cast<GlobalProc*>(&global_proc_placeholder);
  88 }
  89
  90 static void InternalAllocAccess() {
  91   global_proc()->internal_alloc_mtx.Lock();
  92   global_proc()->internal_alloc_mtx.Unlock();
  93 }
  94
  95 ScopedGlobalProcessor::ScopedGlobalProcessor() {
  96   GlobalProc *gp = global_proc();
  97   ThreadState *thr = cur_thread();
  98   if (thr->proc())
  99     return;
 100   // If we don't have a proc, use the global one.
 101   // There are currently only two known case where this path is triggered:
 102   //   __interceptor_free
 103   //   __nptl_deallocate_tsd
 104   //   start_thread
 105   //   clone
 106   // and:
 107   //   ResetRange
 108   //   __interceptor_munmap
 109   //   __deallocate_stack
 110   //   start_thread
 111   //   clone
 112   // Ideally, we destroy thread state (and unwire proc) when a thread actually
 113   // exits (i.e. when we join/wait it). Then we would not need the global proc
 114   gp->mtx.Lock();
 115   ProcWire(gp->proc, thr);
 116 }
 117
 118 ScopedGlobalProcessor::~ScopedGlobalProcessor() {
 119   GlobalProc *gp = global_proc();
 120   ThreadState *thr = cur_thread();
 121   if (thr->proc() != gp->proc)
 122     return;
 123   ProcUnwire(gp->proc, thr);
 124   gp->mtx.Unlock();
 125 }
 126
 127 void AllocatorLock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 128   global_proc()->internal_alloc_mtx.Lock();
 129   InternalAllocatorLock();
 130 }
 131
 132 void AllocatorUnlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 133   InternalAllocatorUnlock();
 134   global_proc()->internal_alloc_mtx.Unlock();
 135 }
 136
 137 void GlobalProcessorLock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 138   global_proc()->mtx.Lock();
 139 }
 140
 141 void GlobalProcessorUnlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 142   global_proc()->mtx.Unlock();
 143 }
 144
 145 static constexpr uptr kMaxAllowedMallocSize = 1ull << 40;
 146 static uptr max_user_defined_malloc_size;
 147
 148 void InitializeAllocator() {
 149   SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
 150   allocator()->Init(common_flags()->allocator_release_to_os_interval_ms);
 151   max_user_defined_malloc_size = common_flags()->max_allocation_size_mb
 152                                      ? common_flags()->max_allocation_size_mb
 153                                            << 20
 154                                      : kMaxAllowedMallocSize;
 155 }
 156
 157 void InitializeAllocatorLate() {
 158   new(global_proc()) GlobalProc();
 159 }
 160
 161 void AllocatorProcStart(Processor *proc) {
 162   allocator()->InitCache(&proc->alloc_cache);
 163   internal_allocator()->InitCache(&proc->internal_alloc_cache);
 164 }
 165
 166 void AllocatorProcFinish(Processor *proc) {
 167   allocator()->DestroyCache(&proc->alloc_cache);
 168   internal_allocator()->DestroyCache(&proc->internal_alloc_cache);
 169 }
 170
 171 void AllocatorPrintStats() {
 172   allocator()->PrintStats();
 173 }
 174
 175 static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
 176   if (atomic_load_relaxed(&thr->in_signal_handler) == 0 ||
 177       !ShouldReport(thr, ReportTypeSignalUnsafe))
 178     return;
 179   VarSizeStackTrace stack;
 180   ObtainCurrentStack(thr, pc, &stack);
 181   if (IsFiredSuppression(ctx, ReportTypeSignalUnsafe, stack))
 182     return;
 183   ThreadRegistryLock l(&ctx->thread_registry);
 184   ScopedReport rep(ReportTypeSignalUnsafe);
 185   rep.AddStack(stack, true);
 186   OutputReport(thr, rep);
 187 }
 188
 189
 190 void *user_alloc_internal(ThreadState *thr, uptr pc, uptr sz, uptr align,
 191                           bool signal) {
 192   if (sz >= kMaxAllowedMallocSize || align >= kMaxAllowedMallocSize ||
 193       sz > max_user_defined_malloc_size) {
 194     if (AllocatorMayReturnNull())
 195       return nullptr;
 196     uptr malloc_limit =
 197         Min(kMaxAllowedMallocSize, max_user_defined_malloc_size);
 198     GET_STACK_TRACE_FATAL(thr, pc);
 199     ReportAllocationSizeTooBig(sz, malloc_limit, &stack);
 200   }
 201   if (UNLIKELY(IsRssLimitExceeded())) {
 202     if (AllocatorMayReturnNull())
 203       return nullptr;
 204     GET_STACK_TRACE_FATAL(thr, pc);
 205     ReportRssLimitExceeded(&stack);
 206   }
 207   void *p = allocator()->Allocate(&thr->proc()->alloc_cache, sz, align);
 208   if (UNLIKELY(!p)) {
 209     SetAllocatorOutOfMemory();
 210     if (AllocatorMayReturnNull())
 211       return nullptr;
 212     GET_STACK_TRACE_FATAL(thr, pc);
 213     ReportOutOfMemory(sz, &stack);
 214   }
 215   if (ctx && ctx->initialized)
 216     OnUserAlloc(thr, pc, (uptr)p, sz, true);
 217   if (signal)
 218     SignalUnsafeCall(thr, pc);
 219   return p;
 220 }
 221
 222 void user_free(ThreadState *thr, uptr pc, void *p, bool signal) {
 223   ScopedGlobalProcessor sgp;
 224   if (ctx && ctx->initialized)
 225     OnUserFree(thr, pc, (uptr)p, true);
 226   allocator()->Deallocate(&thr->proc()->alloc_cache, p);
 227   if (signal)
 228     SignalUnsafeCall(thr, pc);
 229 }
 230
 231 void *user_alloc(ThreadState *thr, uptr pc, uptr sz) {
 232   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, kDefaultAlignment));
 233 }
 234
 235 void *user_calloc(ThreadState *thr, uptr pc, uptr size, uptr n) {
 236   if (UNLIKELY(CheckForCallocOverflow(size, n))) {
 237     if (AllocatorMayReturnNull())
 238       return SetErrnoOnNull(nullptr);
 239     GET_STACK_TRACE_FATAL(thr, pc);
 240     ReportCallocOverflow(n, size, &stack);
 241   }
 242   void *p = user_alloc_internal(thr, pc, n * size);
 243   if (p)
 244     internal_memset(p, 0, n * size);
 245   return SetErrnoOnNull(p);
 246 }
 247
 248 void *user_reallocarray(ThreadState *thr, uptr pc, void *p, uptr size, uptr n) {
 249   if (UNLIKELY(CheckForCallocOverflow(size, n))) {
 250     if (AllocatorMayReturnNull())
 251       return SetErrnoOnNull(nullptr);
 252     GET_STACK_TRACE_FATAL(thr, pc);
 253     ReportReallocArrayOverflow(size, n, &stack);
 254   }
 255   return user_realloc(thr, pc, p, size * n);
 256 }
 257
 258 void OnUserAlloc(ThreadState *thr, uptr pc, uptr p, uptr sz, bool write) {
 259   DPrintf("#%d: alloc(%zu) = 0x%zx\n", thr->tid, sz, p);
 260   // Note: this can run before thread initialization/after finalization.
 261   // As a result this is not necessarily synchronized with DoReset,
 262   // which iterates over and resets all sync objects,
 263   // but it is fine to create new MBlocks in this context.
 264   ctx->metamap.AllocBlock(thr, pc, p, sz);
 265   // If this runs before thread initialization/after finalization
 266   // and we don't have trace initialized, we can't imitate writes.
 267   // In such case just reset the shadow range, it is fine since
 268   // it affects only a small fraction of special objects.
 269   if (write && thr->ignore_reads_and_writes == 0 &&
 270       atomic_load_relaxed(&thr->trace_pos))
 271     MemoryRangeImitateWrite(thr, pc, (uptr)p, sz);
 272   else
 273     MemoryResetRange(thr, pc, (uptr)p, sz);
 274 }
 275
 276 void OnUserFree(ThreadState *thr, uptr pc, uptr p, bool write) {
 277   CHECK_NE(p, (void*)0);
 278   if (!thr->slot) {
 279     // Very early/late in thread lifetime, or during fork.
 280     UNUSED uptr sz = ctx->metamap.FreeBlock(thr->proc(), p, false);
 281     DPrintf("#%d: free(0x%zx, %zu) (no slot)\n", thr->tid, p, sz);
 282     return;
 283   }
 284   SlotLocker locker(thr);
 285   uptr sz = ctx->metamap.FreeBlock(thr->proc(), p, true);
 286   DPrintf("#%d: free(0x%zx, %zu)\n", thr->tid, p, sz);
 287   if (write && thr->ignore_reads_and_writes == 0)
 288     MemoryRangeFreed(thr, pc, (uptr)p, sz);
 289 }
 290
 291 void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz) {
 292   // FIXME: Handle "shrinking" more efficiently,
 293   // it seems that some software actually does this.
 294   if (!p)
 295     return SetErrnoOnNull(user_alloc_internal(thr, pc, sz));
 296   if (!sz) {
 297     user_free(thr, pc, p);
 298     return nullptr;
 299   }
 300   void *new_p = user_alloc_internal(thr, pc, sz);
 301   if (new_p) {
 302     uptr old_sz = user_alloc_usable_size(p);
 303     internal_memcpy(new_p, p, min(old_sz, sz));
 304     user_free(thr, pc, p);
 305   }
 306   return SetErrnoOnNull(new_p);
 307 }
 308
 309 void *user_memalign(ThreadState *thr, uptr pc, uptr align, uptr sz) {
 310   if (UNLIKELY(!IsPowerOfTwo(align))) {
 311     errno = errno_EINVAL;
 312     if (AllocatorMayReturnNull())
 313       return nullptr;
 314     GET_STACK_TRACE_FATAL(thr, pc);
 315     ReportInvalidAllocationAlignment(align, &stack);
 316   }
 317   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, align));
 318 }
 319
 320 int user_posix_memalign(ThreadState *thr, uptr pc, void **memptr, uptr align,
 321                         uptr sz) {
 322   if (UNLIKELY(!CheckPosixMemalignAlignment(align))) {
 323     if (AllocatorMayReturnNull())
 324       return errno_EINVAL;
 325     GET_STACK_TRACE_FATAL(thr, pc);
 326     ReportInvalidPosixMemalignAlignment(align, &stack);
 327   }
 328   void *ptr = user_alloc_internal(thr, pc, sz, align);
 329   if (UNLIKELY(!ptr))
 330     // OOM error is already taken care of by user_alloc_internal.
 331     return errno_ENOMEM;
 332   CHECK(IsAligned((uptr)ptr, align));
 333   *memptr = ptr;
 334   return 0;
 335 }
 336
 337 void *user_aligned_alloc(ThreadState *thr, uptr pc, uptr align, uptr sz) {
 338   if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(align, sz))) {
 339     errno = errno_EINVAL;
 340     if (AllocatorMayReturnNull())
 341       return nullptr;
 342     GET_STACK_TRACE_FATAL(thr, pc);
 343     ReportInvalidAlignedAllocAlignment(sz, align, &stack);
 344   }
 345   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, align));
 346 }
 347
 348 void *user_valloc(ThreadState *thr, uptr pc, uptr sz) {
 349   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, GetPageSizeCached()));
 350 }
 351
 352 void *user_pvalloc(ThreadState *thr, uptr pc, uptr sz) {
 353   uptr PageSize = GetPageSizeCached();
 354   if (UNLIKELY(CheckForPvallocOverflow(sz, PageSize))) {
 355     errno = errno_ENOMEM;
 356     if (AllocatorMayReturnNull())
 357       return nullptr;
 358     GET_STACK_TRACE_FATAL(thr, pc);
 359     ReportPvallocOverflow(sz, &stack);
 360   }
 361   // pvalloc(0) should allocate one page.
 362   sz = sz ? RoundUpTo(sz, PageSize) : PageSize;
 363   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, PageSize));
 364 }
 365
 366 uptr user_alloc_usable_size(const void *p) {
 367   if (p == 0 || !IsAppMem((uptr)p))
 368     return 0;
 369   MBlock *b = ctx->metamap.GetBlock((uptr)p);
 370   if (!b)
 371     return 0;  // Not a valid pointer.
 372   if (b->siz == 0)
 373     return 1;  // Zero-sized allocations are actually 1 byte.
 374   return b->siz;
 375 }
 376
 377 void invoke_malloc_hook(void *ptr, uptr size) {
 378   ThreadState *thr = cur_thread();
 379   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
 380     return;
 381   __sanitizer_malloc_hook(ptr, size);
 382   RunMallocHooks(ptr, size);
 383 }
 384
 385 void invoke_free_hook(void *ptr) {
 386   ThreadState *thr = cur_thread();
 387   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
 388     return;
 389   __sanitizer_free_hook(ptr);
 390   RunFreeHooks(ptr);
 391 }
 392
 393 void *Alloc(uptr sz) {
 394   ThreadState *thr = cur_thread();
 395   if (thr->nomalloc) {
 396     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 397     CHECK(0);
 398   }
 399   InternalAllocAccess();
 400   return InternalAlloc(sz, &thr->proc()->internal_alloc_cache);
 401 }
 402
 403 void FreeImpl(void *p) {
 404   ThreadState *thr = cur_thread();
 405   if (thr->nomalloc) {
 406     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 407     CHECK(0);
 408   }
 409   InternalAllocAccess();
 410   InternalFree(p, &thr->proc()->internal_alloc_cache);
 411 }
 412
 413 }  // namespace __tsan
 414
 415 using namespace __tsan;
 416
 417 extern "C" {
 418 uptr __sanitizer_get_current_allocated_bytes() {
 419   uptr stats[AllocatorStatCount];
 420   allocator()->GetStats(stats);
 421   return stats[AllocatorStatAllocated];
 422 }
 423
 424 uptr __sanitizer_get_heap_size() {
 425   uptr stats[AllocatorStatCount];
 426   allocator()->GetStats(stats);
 427   return stats[AllocatorStatMapped];
 428 }
 429
 430 uptr __sanitizer_get_free_bytes() {
 431   return 1;
 432 }
 433
 434 uptr __sanitizer_get_unmapped_bytes() {
 435   return 1;
 436 }
 437
 438 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
 439   return size;
 440 }
 441
 442 int __sanitizer_get_ownership(const void *p) {
 443   return allocator()->GetBlockBegin(p) != 0;
 444 }
 445
 446 uptr __sanitizer_get_allocated_size(const void *p) {
 447   return user_alloc_usable_size(p);
 448 }
 449
 450 void __tsan_on_thread_idle() {
 451   ThreadState *thr = cur_thread();
 452   allocator()->SwallowCache(&thr->proc()->alloc_cache);
 453   internal_allocator()->SwallowCache(&thr->proc()->internal_alloc_cache);
 454   ctx->metamap.OnProcIdle(thr->proc());
 455 }
 456 }  // extern "C"