libsanitizer/asan/asan_thread.cc

   1 //===-- asan_thread.cc ----------------------------------------------------===//
   2 //
   3 // This file is distributed under the University of Illinois Open Source
   4 // License. See LICENSE.TXT for details.
   5 //
   6 //===----------------------------------------------------------------------===//
   7 //
   8 // This file is a part of AddressSanitizer, an address sanity checker.
   9 //
  10 // Thread-related code.
  11 //===----------------------------------------------------------------------===//
  12 #include "asan_allocator.h"
  13 #include "asan_interceptors.h"
  14 #include "asan_stack.h"
  15 #include "asan_thread.h"
  16 #include "asan_thread_registry.h"
  17 #include "asan_mapping.h"
  18 #include "sanitizer_common/sanitizer_common.h"
  19
  20 namespace __asan {
  21
  22 AsanThread::AsanThread(LinkerInitialized x)
  23     : fake_stack_(x),
  24       malloc_storage_(x),
  25       stats_(x) { }
  26
  27 AsanThread *AsanThread::Create(u32 parent_tid, thread_callback_t start_routine,
  28                                void *arg, StackTrace *stack) {
  29   uptr PageSize = GetPageSizeCached();
  30   uptr size = RoundUpTo(sizeof(AsanThread), PageSize);
  31   AsanThread *thread = (AsanThread*)MmapOrDie(size, __FUNCTION__);
  32   thread->start_routine_ = start_routine;
  33   thread->arg_ = arg;
  34
  35   const uptr kSummaryAllocSize = PageSize;
  36   CHECK_LE(sizeof(AsanThreadSummary), kSummaryAllocSize);
  37   AsanThreadSummary *summary =
  38       (AsanThreadSummary*)MmapOrDie(PageSize, "AsanThreadSummary");
  39   summary->Init(parent_tid, stack);
  40   summary->set_thread(thread);
  41   thread->set_summary(summary);
  42
  43   return thread;
  44 }
  45
  46 void AsanThreadSummary::TSDDtor(void *tsd) {
  47   AsanThreadSummary *summary = (AsanThreadSummary*)tsd;
  48   if (flags()->verbosity >= 1) {
  49     Report("T%d TSDDtor\n", summary->tid());
  50   }
  51   if (summary->thread()) {
  52     summary->thread()->Destroy();
  53   }
  54 }
  55
  56 void AsanThread::Destroy() {
  57   if (flags()->verbosity >= 1) {
  58     Report("T%d exited\n", tid());
  59   }
  60
  61   asanThreadRegistry().UnregisterThread(this);
  62   CHECK(summary()->thread() == 0);
  63   // We also clear the shadow on thread destruction because
  64   // some code may still be executing in later TSD destructors
  65   // and we don't want it to have any poisoned stack.
  66   ClearShadowForThreadStack();
  67   fake_stack().Cleanup();
  68   uptr size = RoundUpTo(sizeof(AsanThread), GetPageSizeCached());
  69   UnmapOrDie(this, size);
  70 }
  71
  72 void AsanThread::Init() {
  73   SetThreadStackTopAndBottom();
  74   CHECK(AddrIsInMem(stack_bottom_));
  75   CHECK(AddrIsInMem(stack_top_ - 1));
  76   ClearShadowForThreadStack();
  77   if (flags()->verbosity >= 1) {
  78     int local = 0;
  79     Report("T%d: stack [%p,%p) size 0x%zx; local=%p\n",
  80            tid(), (void*)stack_bottom_, (void*)stack_top_,
  81            stack_top_ - stack_bottom_, &local);
  82   }
  83   fake_stack_.Init(stack_size());
  84   AsanPlatformThreadInit();
  85 }
  86
  87 thread_return_t AsanThread::ThreadStart() {
  88   Init();
  89   if (flags()->use_sigaltstack) SetAlternateSignalStack();
  90
  91   if (!start_routine_) {
  92     // start_routine_ == 0 if we're on the main thread or on one of the
  93     // OS X libdispatch worker threads. But nobody is supposed to call
  94     // ThreadStart() for the worker threads.
  95     CHECK(tid() == 0);
  96     return 0;
  97   }
  98
  99   thread_return_t res = start_routine_(arg_);
 100   malloc_storage().CommitBack();
 101   if (flags()->use_sigaltstack) UnsetAlternateSignalStack();
 102
 103   this->Destroy();
 104
 105   return res;
 106 }
 107
 108 void AsanThread::SetThreadStackTopAndBottom() {
 109   GetThreadStackTopAndBottom(tid() == 0, &stack_top_, &stack_bottom_);
 110   int local;
 111   CHECK(AddrIsInStack((uptr)&local));
 112 }
 113
 114 void AsanThread::ClearShadowForThreadStack() {
 115   PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0);
 116 }
 117
 118 const char *AsanThread::GetFrameNameByAddr(uptr addr, uptr *offset) {
 119   uptr bottom = 0;
 120   if (AddrIsInStack(addr)) {
 121     bottom = stack_bottom();
 122   } else {
 123     bottom = fake_stack().AddrIsInFakeStack(addr);
 124     CHECK(bottom);
 125     *offset = addr - bottom;
 126     return  (const char *)((uptr*)bottom)[1];
 127   }
 128   uptr aligned_addr = addr & ~(SANITIZER_WORDSIZE/8 - 1);  // align addr.
 129   u8 *shadow_ptr = (u8*)MemToShadow(aligned_addr);
 130   u8 *shadow_bottom = (u8*)MemToShadow(bottom);
 131
 132   while (shadow_ptr >= shadow_bottom &&
 133          *shadow_ptr != kAsanStackLeftRedzoneMagic) {
 134     shadow_ptr--;
 135   }
 136
 137   while (shadow_ptr >= shadow_bottom &&
 138          *shadow_ptr == kAsanStackLeftRedzoneMagic) {
 139     shadow_ptr--;
 140   }
 141
 142   if (shadow_ptr < shadow_bottom) {
 143     *offset = 0;
 144     return "UNKNOWN";
 145   }
 146
 147   uptr* ptr = (uptr*)SHADOW_TO_MEM((uptr)(shadow_ptr + 1));
 148   CHECK(ptr[0] == kCurrentStackFrameMagic);
 149   *offset = addr - (uptr)ptr;
 150   return (const char*)ptr[1];
 151 }
 152
 153 }  // namespace __asan