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 OnMapSecondary(uptr p, uptr size, uptr user_begin,
  29                       uptr user_size) const {};
  30   void OnUnmap(uptr p, uptr size) const {
  31     // We are about to unmap a chunk of user memory.
  32     // Mark the corresponding shadow memory as not needed.
  33     DontNeedShadowFor(p, size);
  34     // Mark the corresponding meta shadow memory as not needed.
  35     // Note the block does not contain any meta info at this point
  36     // (this happens after free).
  37     const uptr kMetaRatio = kMetaShadowCell / kMetaShadowSize;
  38     const uptr kPageSize = GetPageSizeCached() * kMetaRatio;
  39     // Block came from LargeMmapAllocator, so must be large.
  40     // We rely on this in the calculations below.
  41     CHECK_GE(size, 2 * kPageSize);
  42     uptr diff = RoundUp(p, kPageSize) - p;
  43     if (diff != 0) {
  44       p += diff;
  45       size -= diff;
  46     }
  47     diff = p + size - RoundDown(p + size, kPageSize);
  48     if (diff != 0)
  49       size -= diff;
  50     uptr p_meta = (uptr)MemToMeta(p);
  51     ReleaseMemoryPagesToOS(p_meta, p_meta + size / kMetaRatio);
  52   }
  53 };
  54
  55 static char allocator_placeholder[sizeof(Allocator)] ALIGNED(64);
  56 Allocator *allocator() {
  57   return reinterpret_cast<Allocator*>(&allocator_placeholder);
  58 }
  59
  60 struct GlobalProc {
  61   Mutex mtx;
  62   Processor *proc;
  63   // This mutex represents the internal allocator combined for
  64   // the purposes of deadlock detection. The internal allocator
  65   // uses multiple mutexes, moreover they are locked only occasionally
  66   // and they are spin mutexes which don't support deadlock detection.
  67   // So we use this fake mutex to serve as a substitute for these mutexes.
  68   CheckedMutex internal_alloc_mtx;
  69
  70   GlobalProc()
  71       : mtx(MutexTypeGlobalProc),
  72         proc(ProcCreate()),
  73         internal_alloc_mtx(MutexTypeInternalAlloc) {}
  74 };
  75
  76 static char global_proc_placeholder[sizeof(GlobalProc)] ALIGNED(64);
  77 GlobalProc *global_proc() {
  78   return reinterpret_cast<GlobalProc*>(&global_proc_placeholder);
  79 }
  80
  81 static void InternalAllocAccess() {
  82   global_proc()->internal_alloc_mtx.Lock();
  83   global_proc()->internal_alloc_mtx.Unlock();
  84 }
  85
  86 ScopedGlobalProcessor::ScopedGlobalProcessor() {
  87   GlobalProc *gp = global_proc();
  88   ThreadState *thr = cur_thread();
  89   if (thr->proc())
  90     return;
  91   // If we don't have a proc, use the global one.
  92   // There are currently only two known case where this path is triggered:
  93   //   __interceptor_free
  94   //   __nptl_deallocate_tsd
  95   //   start_thread
  96   //   clone
  97   // and:
  98   //   ResetRange
  99   //   __interceptor_munmap
 100   //   __deallocate_stack
 101   //   start_thread
 102   //   clone
 103   // Ideally, we destroy thread state (and unwire proc) when a thread actually
 104   // exits (i.e. when we join/wait it). Then we would not need the global proc
 105   gp->mtx.Lock();
 106   ProcWire(gp->proc, thr);
 107 }
 108
 109 ScopedGlobalProcessor::~ScopedGlobalProcessor() {
 110   GlobalProc *gp = global_proc();
 111   ThreadState *thr = cur_thread();
 112   if (thr->proc() != gp->proc)
 113     return;
 114   ProcUnwire(gp->proc, thr);
 115   gp->mtx.Unlock();
 116 }
 117
 118 void AllocatorLock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 119   global_proc()->internal_alloc_mtx.Lock();
 120   InternalAllocatorLock();
 121 }
 122
 123 void AllocatorUnlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 124   InternalAllocatorUnlock();
 125   global_proc()->internal_alloc_mtx.Unlock();
 126 }
 127
 128 void GlobalProcessorLock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 129   global_proc()->mtx.Lock();
 130 }
 131
 132 void GlobalProcessorUnlock() SANITIZER_NO_THREAD_SAFETY_ANALYSIS {
 133   global_proc()->mtx.Unlock();
 134 }
 135
 136 static constexpr uptr kMaxAllowedMallocSize = 1ull << 40;
 137 static uptr max_user_defined_malloc_size;
 138
 139 void InitializeAllocator() {
 140   SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
 141   allocator()->Init(common_flags()->allocator_release_to_os_interval_ms);
 142   max_user_defined_malloc_size = common_flags()->max_allocation_size_mb
 143                                      ? common_flags()->max_allocation_size_mb
 144                                            << 20
 145                                      : kMaxAllowedMallocSize;
 146 }
 147
 148 void InitializeAllocatorLate() {
 149   new(global_proc()) GlobalProc();
 150 }
 151
 152 void AllocatorProcStart(Processor *proc) {
 153   allocator()->InitCache(&proc->alloc_cache);
 154   internal_allocator()->InitCache(&proc->internal_alloc_cache);
 155 }
 156
 157 void AllocatorProcFinish(Processor *proc) {
 158   allocator()->DestroyCache(&proc->alloc_cache);
 159   internal_allocator()->DestroyCache(&proc->internal_alloc_cache);
 160 }
 161
 162 void AllocatorPrintStats() {
 163   allocator()->PrintStats();
 164 }
 165
 166 static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
 167   if (atomic_load_relaxed(&thr->in_signal_handler) == 0 ||
 168       !ShouldReport(thr, ReportTypeSignalUnsafe))
 169     return;
 170   VarSizeStackTrace stack;
 171   ObtainCurrentStack(thr, pc, &stack);
 172   if (IsFiredSuppression(ctx, ReportTypeSignalUnsafe, stack))
 173     return;
 174   ThreadRegistryLock l(&ctx->thread_registry);
 175   ScopedReport rep(ReportTypeSignalUnsafe);
 176   rep.AddStack(stack, true);
 177   OutputReport(thr, rep);
 178 }
 179
 180
 181 void *user_alloc_internal(ThreadState *thr, uptr pc, uptr sz, uptr align,
 182                           bool signal) {
 183   if (sz >= kMaxAllowedMallocSize || align >= kMaxAllowedMallocSize ||
 184       sz > max_user_defined_malloc_size) {
 185     if (AllocatorMayReturnNull())
 186       return nullptr;
 187     uptr malloc_limit =
 188         Min(kMaxAllowedMallocSize, max_user_defined_malloc_size);
 189     GET_STACK_TRACE_FATAL(thr, pc);
 190     ReportAllocationSizeTooBig(sz, malloc_limit, &stack);
 191   }
 192   if (UNLIKELY(IsRssLimitExceeded())) {
 193     if (AllocatorMayReturnNull())
 194       return nullptr;
 195     GET_STACK_TRACE_FATAL(thr, pc);
 196     ReportRssLimitExceeded(&stack);
 197   }
 198   void *p = allocator()->Allocate(&thr->proc()->alloc_cache, sz, align);
 199   if (UNLIKELY(!p)) {
 200     SetAllocatorOutOfMemory();
 201     if (AllocatorMayReturnNull())
 202       return nullptr;
 203     GET_STACK_TRACE_FATAL(thr, pc);
 204     ReportOutOfMemory(sz, &stack);
 205   }
 206   if (ctx && ctx->initialized)
 207     OnUserAlloc(thr, pc, (uptr)p, sz, true);
 208   if (signal)
 209     SignalUnsafeCall(thr, pc);
 210   return p;
 211 }
 212
 213 void user_free(ThreadState *thr, uptr pc, void *p, bool signal) {
 214   ScopedGlobalProcessor sgp;
 215   if (ctx && ctx->initialized)
 216     OnUserFree(thr, pc, (uptr)p, true);
 217   allocator()->Deallocate(&thr->proc()->alloc_cache, p);
 218   if (signal)
 219     SignalUnsafeCall(thr, pc);
 220 }
 221
 222 void *user_alloc(ThreadState *thr, uptr pc, uptr sz) {
 223   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, kDefaultAlignment));
 224 }
 225
 226 void *user_calloc(ThreadState *thr, uptr pc, uptr size, uptr n) {
 227   if (UNLIKELY(CheckForCallocOverflow(size, n))) {
 228     if (AllocatorMayReturnNull())
 229       return SetErrnoOnNull(nullptr);
 230     GET_STACK_TRACE_FATAL(thr, pc);
 231     ReportCallocOverflow(n, size, &stack);
 232   }
 233   void *p = user_alloc_internal(thr, pc, n * size);
 234   if (p)
 235     internal_memset(p, 0, n * size);
 236   return SetErrnoOnNull(p);
 237 }
 238
 239 void *user_reallocarray(ThreadState *thr, uptr pc, void *p, uptr size, uptr n) {
 240   if (UNLIKELY(CheckForCallocOverflow(size, n))) {
 241     if (AllocatorMayReturnNull())
 242       return SetErrnoOnNull(nullptr);
 243     GET_STACK_TRACE_FATAL(thr, pc);
 244     ReportReallocArrayOverflow(size, n, &stack);
 245   }
 246   return user_realloc(thr, pc, p, size * n);
 247 }
 248
 249 void OnUserAlloc(ThreadState *thr, uptr pc, uptr p, uptr sz, bool write) {
 250   DPrintf("#%d: alloc(%zu) = 0x%zx\n", thr->tid, sz, p);
 251   // Note: this can run before thread initialization/after finalization.
 252   // As a result this is not necessarily synchronized with DoReset,
 253   // which iterates over and resets all sync objects,
 254   // but it is fine to create new MBlocks in this context.
 255   ctx->metamap.AllocBlock(thr, pc, p, sz);
 256   // If this runs before thread initialization/after finalization
 257   // and we don't have trace initialized, we can't imitate writes.
 258   // In such case just reset the shadow range, it is fine since
 259   // it affects only a small fraction of special objects.
 260   if (write && thr->ignore_reads_and_writes == 0 &&
 261       atomic_load_relaxed(&thr->trace_pos))
 262     MemoryRangeImitateWrite(thr, pc, (uptr)p, sz);
 263   else
 264     MemoryResetRange(thr, pc, (uptr)p, sz);
 265 }
 266
 267 void OnUserFree(ThreadState *thr, uptr pc, uptr p, bool write) {
 268   CHECK_NE(p, (void*)0);
 269   if (!thr->slot) {
 270     // Very early/late in thread lifetime, or during fork.
 271     UNUSED uptr sz = ctx->metamap.FreeBlock(thr->proc(), p, false);
 272     DPrintf("#%d: free(0x%zx, %zu) (no slot)\n", thr->tid, p, sz);
 273     return;
 274   }
 275   SlotLocker locker(thr);
 276   uptr sz = ctx->metamap.FreeBlock(thr->proc(), p, true);
 277   DPrintf("#%d: free(0x%zx, %zu)\n", thr->tid, p, sz);
 278   if (write && thr->ignore_reads_and_writes == 0)
 279     MemoryRangeFreed(thr, pc, (uptr)p, sz);
 280 }
 281
 282 void *user_realloc(ThreadState *thr, uptr pc, void *p, uptr sz) {
 283   // FIXME: Handle "shrinking" more efficiently,
 284   // it seems that some software actually does this.
 285   if (!p)
 286     return SetErrnoOnNull(user_alloc_internal(thr, pc, sz));
 287   if (!sz) {
 288     user_free(thr, pc, p);
 289     return nullptr;
 290   }
 291   void *new_p = user_alloc_internal(thr, pc, sz);
 292   if (new_p) {
 293     uptr old_sz = user_alloc_usable_size(p);
 294     internal_memcpy(new_p, p, min(old_sz, sz));
 295     user_free(thr, pc, p);
 296   }
 297   return SetErrnoOnNull(new_p);
 298 }
 299
 300 void *user_memalign(ThreadState *thr, uptr pc, uptr align, uptr sz) {
 301   if (UNLIKELY(!IsPowerOfTwo(align))) {
 302     errno = errno_EINVAL;
 303     if (AllocatorMayReturnNull())
 304       return nullptr;
 305     GET_STACK_TRACE_FATAL(thr, pc);
 306     ReportInvalidAllocationAlignment(align, &stack);
 307   }
 308   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, align));
 309 }
 310
 311 int user_posix_memalign(ThreadState *thr, uptr pc, void **memptr, uptr align,
 312                         uptr sz) {
 313   if (UNLIKELY(!CheckPosixMemalignAlignment(align))) {
 314     if (AllocatorMayReturnNull())
 315       return errno_EINVAL;
 316     GET_STACK_TRACE_FATAL(thr, pc);
 317     ReportInvalidPosixMemalignAlignment(align, &stack);
 318   }
 319   void *ptr = user_alloc_internal(thr, pc, sz, align);
 320   if (UNLIKELY(!ptr))
 321     // OOM error is already taken care of by user_alloc_internal.
 322     return errno_ENOMEM;
 323   CHECK(IsAligned((uptr)ptr, align));
 324   *memptr = ptr;
 325   return 0;
 326 }
 327
 328 void *user_aligned_alloc(ThreadState *thr, uptr pc, uptr align, uptr sz) {
 329   if (UNLIKELY(!CheckAlignedAllocAlignmentAndSize(align, sz))) {
 330     errno = errno_EINVAL;
 331     if (AllocatorMayReturnNull())
 332       return nullptr;
 333     GET_STACK_TRACE_FATAL(thr, pc);
 334     ReportInvalidAlignedAllocAlignment(sz, align, &stack);
 335   }
 336   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, align));
 337 }
 338
 339 void *user_valloc(ThreadState *thr, uptr pc, uptr sz) {
 340   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, GetPageSizeCached()));
 341 }
 342
 343 void *user_pvalloc(ThreadState *thr, uptr pc, uptr sz) {
 344   uptr PageSize = GetPageSizeCached();
 345   if (UNLIKELY(CheckForPvallocOverflow(sz, PageSize))) {
 346     errno = errno_ENOMEM;
 347     if (AllocatorMayReturnNull())
 348       return nullptr;
 349     GET_STACK_TRACE_FATAL(thr, pc);
 350     ReportPvallocOverflow(sz, &stack);
 351   }
 352   // pvalloc(0) should allocate one page.
 353   sz = sz ? RoundUpTo(sz, PageSize) : PageSize;
 354   return SetErrnoOnNull(user_alloc_internal(thr, pc, sz, PageSize));
 355 }
 356
 357 static const void *user_alloc_begin(const void *p) {
 358   if (p == nullptr || !IsAppMem((uptr)p))
 359     return nullptr;
 360   void *beg = allocator()->GetBlockBegin(p);
 361   if (!beg)
 362     return nullptr;
 363
 364   MBlock *b = ctx->metamap.GetBlock((uptr)beg);
 365   if (!b)
 366     return nullptr;  // Not a valid pointer.
 367
 368   return (const void *)beg;
 369 }
 370
 371 uptr user_alloc_usable_size(const void *p) {
 372   if (p == 0 || !IsAppMem((uptr)p))
 373     return 0;
 374   MBlock *b = ctx->metamap.GetBlock((uptr)p);
 375   if (!b)
 376     return 0;  // Not a valid pointer.
 377   if (b->siz == 0)
 378     return 1;  // Zero-sized allocations are actually 1 byte.
 379   return b->siz;
 380 }
 381
 382 uptr user_alloc_usable_size_fast(const void *p) {
 383   MBlock *b = ctx->metamap.GetBlock((uptr)p);
 384   // Static objects may have malloc'd before tsan completes
 385   // initialization, and may believe returned ptrs to be valid.
 386   if (!b)
 387     return 0;  // Not a valid pointer.
 388   if (b->siz == 0)
 389     return 1;  // Zero-sized allocations are actually 1 byte.
 390   return b->siz;
 391 }
 392
 393 void invoke_malloc_hook(void *ptr, uptr size) {
 394   ThreadState *thr = cur_thread();
 395   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
 396     return;
 397   RunMallocHooks(ptr, size);
 398 }
 399
 400 void invoke_free_hook(void *ptr) {
 401   ThreadState *thr = cur_thread();
 402   if (ctx == 0 || !ctx->initialized || thr->ignore_interceptors)
 403     return;
 404   RunFreeHooks(ptr);
 405 }
 406
 407 void *Alloc(uptr sz) {
 408   ThreadState *thr = cur_thread();
 409   if (thr->nomalloc) {
 410     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 411     CHECK(0);
 412   }
 413   InternalAllocAccess();
 414   return InternalAlloc(sz, &thr->proc()->internal_alloc_cache);
 415 }
 416
 417 void FreeImpl(void *p) {
 418   ThreadState *thr = cur_thread();
 419   if (thr->nomalloc) {
 420     thr->nomalloc = 0;  // CHECK calls internal_malloc().
 421     CHECK(0);
 422   }
 423   InternalAllocAccess();
 424   InternalFree(p, &thr->proc()->internal_alloc_cache);
 425 }
 426
 427 }  // namespace __tsan
 428
 429 using namespace __tsan;
 430
 431 extern "C" {
 432 uptr __sanitizer_get_current_allocated_bytes() {
 433   uptr stats[AllocatorStatCount];
 434   allocator()->GetStats(stats);
 435   return stats[AllocatorStatAllocated];
 436 }
 437
 438 uptr __sanitizer_get_heap_size() {
 439   uptr stats[AllocatorStatCount];
 440   allocator()->GetStats(stats);
 441   return stats[AllocatorStatMapped];
 442 }
 443
 444 uptr __sanitizer_get_free_bytes() {
 445   return 1;
 446 }
 447
 448 uptr __sanitizer_get_unmapped_bytes() {
 449   return 1;
 450 }
 451
 452 uptr __sanitizer_get_estimated_allocated_size(uptr size) {
 453   return size;
 454 }
 455
 456 int __sanitizer_get_ownership(const void *p) {
 457   return allocator()->GetBlockBegin(p) != 0;
 458 }
 459
 460 const void *__sanitizer_get_allocated_begin(const void *p) {
 461   return user_alloc_begin(p);
 462 }
 463
 464 uptr __sanitizer_get_allocated_size(const void *p) {
 465   return user_alloc_usable_size(p);
 466 }
 467
 468 uptr __sanitizer_get_allocated_size_fast(const void *p) {
 469   DCHECK_EQ(p, __sanitizer_get_allocated_begin(p));
 470   uptr ret = user_alloc_usable_size_fast(p);
 471   DCHECK_EQ(ret, __sanitizer_get_allocated_size(p));
 472   return ret;
 473 }
 474
 475 void __sanitizer_purge_allocator() {
 476   allocator()->ForceReleaseToOS();
 477 }
 478
 479 void __tsan_on_thread_idle() {
 480   ThreadState *thr = cur_thread();
 481   allocator()->SwallowCache(&thr->proc()->alloc_cache);
 482   internal_allocator()->SwallowCache(&thr->proc()->internal_alloc_cache);
 483   ctx->metamap.OnProcIdle(thr->proc());
 484 }
 485 }  // extern "C"