libsanitizer/tsan/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_interface.h"
  19 #include "tsan_mman.h"
  20 #include "tsan_rtl.h"
  21 #include "tsan_report.h"
  22 #include "tsan_flags.h"
  23
  24 namespace __tsan {
  25
  26 struct MapUnmapCallback {
  27   void OnMap(uptr p, uptr size) const { }
  28   void OnUnmap(uptr p, uptr size) const {
  29     // We are about to unmap a chunk of user memory.
  30     // Mark the corresponding shadow memory as not needed.
  31     DontNeedShadowFor(p, size);
  32     // Mark the corresponding meta shadow memory as not needed.
  33     // Note the block does not contain any meta info at this point
  34     // (this happens after free).
  35     const uptr kMetaRatio = kMetaShadowCell / kMetaShadowSize;
  36     const uptr kPageSize = GetPageSizeCached() * kMetaRatio;
  37     // Block came from LargeMmapAllocator, so must be large.
  38     // We rely on this in the calculations below.
  39     CHECK_GE(size, 2 * kPageSize);
  40     uptr diff = RoundUp(p, kPageSize) - p;
  41     if (diff != 0) {
  42       p += diff;
  43       size -= diff;
  44     }
  45     diff = p + size - RoundDown(p + size, kPageSize);
  46     if (diff != 0)
  47       size -= diff;
  48     uptr p_meta = (uptr)MemToMeta(p);
  49     ReleaseMemoryPagesToOS(p_meta, p_meta + size / kMetaRatio);
  50   }
  51 };
  52
  53 static char allocator_placeholder[sizeof(Allocator)] ALIGNED(64);
  54 Allocator *allocator() {
  55   return reinterpret_cast<Allocator*>(&allocator_placeholder);
  56 }
  57
  58 struct GlobalProc {
  59   Mutex mtx;
  60   Processor *proc;
  61   // This mutex represents the internal allocator combined for
  62   // the purposes of deadlock detection. The internal allocator
  63   // uses multiple mutexes, moreover they are locked only occasionally
  64   // and they are spin mutexes which don't support deadlock detection.
  65   // So we use this fake mutex to serve as a substitute for these mutexes.
  66   CheckedMutex internal_alloc_mtx;
  67
  68   GlobalProc()
  69       : mtx(MutexTypeGlobalProc),
  70         proc(ProcCreate()),
  71         internal_alloc_mtx(MutexTypeInternalAlloc) {}
  72 };
  73
  74 static char global_proc_placeholder[sizeof(GlobalProc)] ALIGNED(64);
  75 GlobalProc *global_proc() {
  76   return reinterpret_cast<GlobalProc*>(&global_proc_placeholder);
  77 }
  78
  79 static void InternalAllocAccess() {
  80   global_proc()->internal_alloc_mtx.Lock();
  81   global_proc()->internal_alloc_mtx.Unlock();
  82 }
  83
  84 ScopedGlobalProcessor::ScopedGlobalProcessor() {
  85   GlobalProc *gp = global_proc();
  86   ThreadState *thr = cur_thread();
  87   if (thr->proc())
  88     return;
  89   // If we don't have a proc, use the global one.
  90   // There are currently only two known case where this path is triggered:
  91   //   __interceptor_free
  92   //   __nptl_deallocate_tsd
  93   //   start_thread
  94   //   clone
  95   // and:
  96   //   ResetRange
  97   //   __interceptor_munmap
  98   //   __deallocate_stack
  99   //   start_thread
 100   //   clone
 101   // Ideally, we destroy thread state (and unwire proc) when a thread actually
 102   // exits (i.e. when we join/wait it). Then we would not need the global proc
 103   gp->mtx.Lock();
 104   ProcWire(gp->proc, thr);
 105 }
 106
 107 ScopedGlobalProcessor::~ScopedGlobalProcessor() {
 108   GlobalProc *gp = global_proc();
 109   ThreadState *thr = cur_thread();
 110   if (thr->proc() != gp->proc)
 111     return;
 112   ProcUnwire(gp->proc, thr);
 113   gp->mtx.Unlock();
 114 }
 115
 116 void AllocatorLock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 117   global_proc()->internal_alloc_mtx.Lock();
 118   InternalAllocatorLock();
 119 }
 120
 121 void AllocatorUnlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 122   InternalAllocatorUnlock();
 123   global_proc()->internal_alloc_mtx.Unlock();
 124 }
 125
 126 void GlobalProcessorLock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 127   global_proc()->mtx.Lock();
 128 }
 129
 130 void GlobalProcessorUnlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 131   global_proc()->mtx.Unlock();
 132 }
 133
 134 static constexpr uptr kMaxAllowedMallocSize = 1ull << 40;
 135 static uptr max_user_defined_malloc_size;
 136
 137 void InitializeAllocator() {
 138   SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
 139   allocator()->Init(common_flags()->allocator_release_to_os_interval_ms);
 140   max_user_defined_malloc_size = common_flags()->max_allocation_size_mb
 141                                      ? common_flags()->max_allocation_size_mb
 142                                            << 20
 143                                      : kMaxAllowedMallocSize;
 144 }
 145
 146 void InitializeAllocatorLate() {
 147   new(global_proc()) GlobalProc();
 148 }
 149
 150 void AllocatorProcStart(Processor *proc) {
 151   allocator()->InitCache(&proc->alloc_cache);
 152   internal_allocator()->InitCache(&proc->internal_alloc_cache);
 153 }
 154
 155 void AllocatorProcFinish(Processor *proc) {
 156   allocator()->DestroyCache(&proc->alloc_cache);
 157   internal_allocator()->DestroyCache(&proc->internal_alloc_cache);
 158 }
 159
 160 void AllocatorPrintStats() {
 161   allocator()->PrintStats();
 162 }
 163
 164 static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
 165   if (atomic_load_relaxed(&thr->in_signal_handler) == 0 ||
 166       !ShouldReport(thr, ReportTypeSignalUnsafe))
 167     return;
 168   VarSizeStackTrace stack;
 169   ObtainCurrentStack(thr, pc, &stack);
 170   if (IsFiredSuppression(ctx, ReportTypeSignalUnsafe, stack))
 171     return;
 172   ThreadRegistryLock l(&ctx->thread_registry);
 173   ScopedReport rep(ReportTypeSignalUnsafe);
 174   rep.AddStack(stack, true);
 175   OutputReport(thr, rep);
 176 }
 177
 178
 179 void *user_alloc_internal(ThreadState *thr, uptr pc, uptr sz, uptr align,
 180                           bool signal) {
 181   if (sz >= kMaxAllowedMallocSize || align >= kMaxAllowedMallocSize ||
 182       sz > max_user_defined_malloc_size) {
 183     if (AllocatorMayReturnNull())
 184       return nullptr;
 185     uptr malloc_limit =
 186         Min(kMaxAllowedMallocSize, max_user_defined_malloc_size);
 187     GET_STACK_TRACE_FATAL(thr, pc);
 188     ReportAllocationSizeTooBig(sz, malloc_limit, &stack);
 189   }
 190   if (UNLIKELY(IsRssLimitExceeded())) {
 191     if (AllocatorMayReturnNull())
 192       return nullptr;
 193     GET_STACK_TRACE_FATAL(thr, pc);
 194     ReportRssLimitExceeded(&stack);
 195   }
 196   void *p = allocator()->Allocate(&thr->proc()->alloc_cache, sz, align);
 197   if (UNLIKELY(!p)) {
 198     SetAllocatorOutOfMemory();
 199     if (AllocatorMayReturnNull())
 200       return nullptr;
 201     GET_STACK_TRACE_FATAL(thr, pc);
 202     ReportOutOfMemory(sz, &stack);
 203   }
 204   if (ctx && ctx->initialized)
 205     OnUserAlloc(thr, pc, (uptr)p, sz, true);
 206   if (signal)
 207     SignalUnsafeCall(thr, pc);
 208   return p;
 209 }
 210
 211 void user_free(ThreadState *thr, uptr pc, void *p, bool signal) {
 212   ScopedGlobalProcessor sgp;
 213   if (ctx && ctx->initialized)
 214     OnUserFree(thr, pc, (uptr)p, true);
 215   allocator()->Deallocate(&thr->proc()->alloc_cache, p);
 216   if (signal)
 217     SignalUnsafeCall(thr, pc);
 218 }
 219
 220 void *user_alloc(ThreadState *thr, uptr pc, uptr sz) {
 221   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, kDefaultAlignment));
 222 }
 223
 224 void *user_calloc(ThreadState *thr, uptr pc, uptr size, uptr n) {
 225   if (UNLIKELY(CheckForCallocOverflow(size, n))) {
 226     if (AllocatorMayReturnNull())
 227       return SetErrnoOnNull(nullptr);
 228     GET_STACK_TRACE_FATAL(thr, pc);
 229     ReportCallocOverflow(n, size, &stack);
 230   }
 231   void *p = user_alloc_internal(thr, pc, n * size);
 232   if (p)
 233     internal_memset(p, 0, n * size);
 234   return SetErrnoOnNull(p);
 235 }
 236
 237 void *user_reallocarray(ThreadState *thr, uptr pc, void *p, uptr size, uptr n) {
 238   if (UNLIKELY(CheckForCallocOverflow(size, n))) {
 239     if (AllocatorMayReturnNull())
 240       return SetErrnoOnNull(nullptr);
 241     GET_STACK_TRACE_FATAL(thr, pc);
 242     ReportReallocArrayOverflow(size, n, &stack);
 243   }
 244   return user_realloc(thr, pc, p, size * n);
 245 }
 246
 247 void OnUserAlloc(ThreadState *thr, uptr pc, uptr p, uptr sz, bool write) {
 248   DPrintf("#%d: alloc(%zu) = 0x%zx\n", thr->tid, sz, p);
 249   // Note: this can run before thread initialization/after finalization.
 250   // As a result this is not necessarily synchronized with DoReset,
 251   // which iterates over and resets all sync objects,
 252   // but it is fine to create new MBlocks in this context.
 253   ctx->metamap.AllocBlock(thr, pc, p, sz);
 254   // If this runs before thread initialization/after finalization
 255   // and we don't have trace initialized, we can't imitate writes.
 256   // In such case just reset the shadow range, it is fine since
 257   // it affects only a small fraction of special objects.
 258   if (write && thr->ignore_reads_and_writes == 0 &&
 259       atomic_load_relaxed(&thr->trace_pos))
 260     MemoryRangeImitateWrite(thr, pc, (uptr)p, sz);
 261   else
 262     MemoryResetRange(thr, pc, (uptr)p, sz);
 263 }
 264
 265 void OnUserFree(ThreadState *thr, uptr pc, uptr p, bool write) {
 266   CHECK_NE(p, (void*)0);
 267   if (!thr->slot) {
 268     // Very early/late in thread lifetime, or during fork.
 269     UNUSED uptr sz = ctx->metamap.FreeBlock(thr->proc(), p, false);
 270     DPrintf("#%d: free(0x%zx, %zu) (no slot)\n", thr->tid, p, sz);
 271     return;
 272   }
 273   SlotLocker locker(thr);
 274   uptr sz = ctx->metamap.FreeBlock(thr->proc(), p, true);
 275   DPrintf("#%d: free(0x%zx, %zu)\n", thr->tid, p, sz);
 276   if (write && thr->ignore_reads_and_writes == 0)
 277     MemoryRangeFreed(thr, pc, (uptr)p, sz);
 278 }
 279
 280 void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz) {
 281   // FIXME: Handle "shrinking" more efficiently,
 282   // it seems that some software actually does this.
 283   if (!p)
 284     return SetErrnoOnNull(user_alloc_internal(thr, pc, sz));
 285   if (!sz) {
 286     user_free(thr, pc, p);
 287     return nullptr;
 288   }
 289   void *new_p = user_alloc_internal(thr, pc, sz);
 290   if (new_p) {
 291     uptr old_sz = user_alloc_usable_size(p);
 292     internal_memcpy(new_p, p, min(old_sz, sz));
 293     user_free(thr, pc, p);
 294   }
 295   return SetErrnoOnNull(new_p);
 296 }
 297
 298 void *user_memalign(ThreadState *thr, uptr pc, uptr align, uptr sz) {
 299   if (UNLIKELY(!IsPowerOfTwo(align))) {
 300     errno = errno_EINVAL;
 301     if (AllocatorMayReturnNull())
 302       return nullptr;
 303     GET_STACK_TRACE_FATAL(thr, pc);
 304     ReportInvalidAllocationAlignment(align, &stack);
 305   }
 306   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, align));
 307 }
 308
 309 int user_posix_memalign(ThreadState *thr, uptr pc, void **memptr, uptr align,
 310                         uptr sz) {
 311   if (UNLIKELY(!CheckPosixMemalignAlignment(align))) {
 312     if (AllocatorMayReturnNull())
 313       return errno_EINVAL;
 314     GET_STACK_TRACE_FATAL(thr, pc);
 315     ReportInvalidPosixMemalignAlignment(align, &stack);
 316   }
 317   void *ptr = user_alloc_internal(thr, pc, sz, align);
 318   if (UNLIKELY(!ptr))
 319     // OOM error is already taken care of by user_alloc_internal.
 320     return errno_ENOMEM;
 321   CHECK(IsAligned((uptr)ptr, align));
 322   *memptr = ptr;
 323   return 0;
 324 }
 325
 326 void *user_aligned_alloc(ThreadState *thr, uptr pc, uptr align, uptr sz) {
 327   if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(align, sz))) {
 328     errno = errno_EINVAL;
 329     if (AllocatorMayReturnNull())
 330       return nullptr;
 331     GET_STACK_TRACE_FATAL(thr, pc);
 332     ReportInvalidAlignedAllocAlignment(sz, align, &stack);
 333   }
 334   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, align));
 335 }
 336
 337 void *user_valloc(ThreadState *thr, uptr pc, uptr sz) {
 338   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, GetPageSizeCached()));
 339 }
 340
 341 void *user_pvalloc(ThreadState *thr, uptr pc, uptr sz) {
 342   uptr PageSize = GetPageSizeCached();
 343   if (UNLIKELY(CheckForPvallocOverflow(sz, PageSize))) {
 344     errno = errno_ENOMEM;
 345     if (AllocatorMayReturnNull())
 346       return nullptr;
 347     GET_STACK_TRACE_FATAL(thr, pc);
 348     ReportPvallocOverflow(sz, &stack);
 349   }
 350   // pvalloc(0) should allocate one page.
 351   sz = sz ? RoundUpTo(sz, PageSize) : PageSize;
 352   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, PageSize));
 353 }
 354
 355 static const void *user_alloc_begin(const void *p) {
 356   if (p == nullptr || !IsAppMem((uptr)p))
 357     return nullptr;
 358   void *beg = allocator()->GetBlockBegin(p);
 359   if (!beg)
 360     return nullptr;
 361
 362   MBlock *b = ctx->metamap.GetBlock((uptr)beg);
 363   if (!b)
 364     return nullptr;  // Not a valid pointer.
 365
 366   return (const void *)beg;
 367 }
 368
 369 uptr user_alloc_usable_size(const void *p) {
 370   if (p == 0 || !IsAppMem((uptr)p))
 371     return 0;
 372   MBlock *b = ctx->metamap.GetBlock((uptr)p);
 373   if (!b)
 374     return 0;  // Not a valid pointer.
 375   if (b->siz == 0)
 376     return 1;  // Zero-sized allocations are actually 1 byte.
 377   return b->siz;
 378 }
 379
 380 void invoke_malloc_hook(void *ptr, uptr size) {
 381   ThreadState *thr = cur_thread();
 382   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
 383     return;
 384   RunMallocHooks(ptr, size);
 385 }
 386
 387 void invoke_free_hook(void *ptr) {
 388   ThreadState *thr = cur_thread();
 389   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
 390     return;
 391   RunFreeHooks(ptr);
 392 }
 393
 394 void *Alloc(uptr sz) {
 395   ThreadState *thr = cur_thread();
 396   if (thr->nomalloc) {
 397     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 398     CHECK(0);
 399   }
 400   InternalAllocAccess();
 401   return InternalAlloc(sz, &thr->proc()->internal_alloc_cache);
 402 }
 403
 404 void FreeImpl(void *p) {
 405   ThreadState *thr = cur_thread();
 406   if (thr->nomalloc) {
 407     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 408     CHECK(0);
 409   }
 410   InternalAllocAccess();
 411   InternalFree(p, &thr->proc()->internal_alloc_cache);
 412 }
 413
 414 }  // namespace __tsan
 415
 416 using namespace __tsan;
 417
 418 extern "C" {
 419 uptr __sanitizer_get_current_allocated_bytes() {
 420   uptr stats[AllocatorStatCount];
 421   allocator()->GetStats(stats);
 422   return stats[AllocatorStatAllocated];
 423 }
 424
 425 uptr __sanitizer_get_heap_size() {
 426   uptr stats[AllocatorStatCount];
 427   allocator()->GetStats(stats);
 428   return stats[AllocatorStatMapped];
 429 }
 430
 431 uptr __sanitizer_get_free_bytes() {
 432   return 1;
 433 }
 434
 435 uptr __sanitizer_get_unmapped_bytes() {
 436   return 1;
 437 }
 438
 439 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
 440   return size;
 441 }
 442
 443 int __sanitizer_get_ownership(const void *p) {
 444   return allocator()->GetBlockBegin(p) != 0;
 445 }
 446
 447 const void *__sanitizer_get_allocated_begin(const void *p) {
 448   return user_alloc_begin(p);
 449 }
 450
 451 uptr __sanitizer_get_allocated_size(const void *p) {
 452   return user_alloc_usable_size(p);
 453 }
 454
 455 void __tsan_on_thread_idle() {
 456   ThreadState *thr = cur_thread();
 457   allocator()->SwallowCache(&thr->proc()->alloc_cache);
 458   internal_allocator()->SwallowCache(&thr->proc()->internal_alloc_cache);
 459   ctx->metamap.OnProcIdle(thr->proc());
 460 }
 461 }  // extern "C"