asan_thread.cc revision f58f998066db0231e521169d2f50af439ceecb49 
1//===-- asan_thread.cc ------------------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file is a part of AddressSanitizer, an address sanity checker.
11//
12// Thread-related code.
13//===----------------------------------------------------------------------===//
14#include "asan_allocator.h"
15#include "asan_interceptors.h"
16#include "asan_procmaps.h"
17#include "asan_stack.h"
18#include "asan_thread.h"
19#include "asan_thread_registry.h"
20#include "asan_mapping.h"
21
22namespace __asan {
23
24AsanThread::AsanThread(LinkerInitialized x)
25    : fake_stack_(x),
26      malloc_storage_(x),
27      stats_(x) { }
28
29AsanThread *AsanThread::Create(int parent_tid, void *(*start_routine) (void *),
30                               void *arg, AsanStackTrace *stack) {
31  size_t size = RoundUpTo(sizeof(AsanThread), kPageSize);
32  AsanThread *thread = (AsanThread*)AsanMmapSomewhereOrDie(size, __FUNCTION__);
33  thread->start_routine_ = start_routine;
34  thread->arg_ = arg;
35
36  AsanThreadSummary *summary = new AsanThreadSummary(parent_tid, stack);
37  summary->set_thread(thread);
38  thread->set_summary(summary);
39
40  return thread;
41}
42
43void AsanThreadSummary::TSDDtor(void *tsd) {
44  AsanThreadSummary *summary = (AsanThreadSummary*)tsd;
45  if (FLAG_v >= 1) {
46    Report("T%d TSDDtor\n", summary->tid());
47  }
48  if (summary->thread()) {
49    summary->thread()->Destroy();
50  }
51}
52
53void AsanThread::Destroy() {
54  if (FLAG_v >= 1) {
55    Report("T%d exited\n", tid());
56  }
57
58  asanThreadRegistry().UnregisterThread(this);
59  CHECK(summary()->thread() == NULL);
60  // We also clear the shadow on thread destruction because
61  // some code may still be executing in later TSD destructors
62  // and we don't want it to have any poisoned stack.
63  ClearShadowForThreadStack();
64  fake_stack().Cleanup();
65  size_t size = RoundUpTo(sizeof(AsanThread), kPageSize);
66  AsanUnmapOrDie(this, size);
67}
68
69void AsanThread::Init() {
70  SetThreadStackTopAndBottom();
71  CHECK(AddrIsInMem(stack_bottom_));
72  CHECK(AddrIsInMem(stack_top_));
73  ClearShadowForThreadStack();
74  if (FLAG_v >= 1) {
75    int local = 0;
76    Report("T%d: stack [%p,%p) size 0x%lx; local=%p\n",
77           tid(), stack_bottom_, stack_top_,
78           stack_top_ - stack_bottom_, &local);
79  }
80  fake_stack_.Init(stack_size());
81}
82
83void *AsanThread::ThreadStart() {
84  Init();
85
86  if (!start_routine_) {
87    // start_routine_ == NULL if we're on the main thread or on one of the
88    // OS X libdispatch worker threads. But nobody is supposed to call
89    // ThreadStart() for the worker threads.
90    CHECK(tid() == 0);
91    return 0;
92  }
93
94  void *res = start_routine_(arg_);
95  malloc_storage().CommitBack();
96
97  this->Destroy();
98
99  return res;
100}
101
102void AsanThread::ClearShadowForThreadStack() {
103  PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0);
104}
105
106const char *AsanThread::GetFrameNameByAddr(uintptr_t addr, uintptr_t *offset) {
107  uintptr_t bottom = 0;
108  bool is_fake_stack = false;
109  if (AddrIsInStack(addr)) {
110    bottom = stack_bottom();
111  } else {
112    bottom = fake_stack().AddrIsInFakeStack(addr);
113    CHECK(bottom);
114    is_fake_stack = true;
115  }
116  uintptr_t aligned_addr = addr & ~(__WORDSIZE/8 - 1);  // align addr.
117  uintptr_t *ptr = (uintptr_t*)aligned_addr;
118  while (ptr >= (uintptr_t*)bottom) {
119    if (ptr[0] == kCurrentStackFrameMagic ||
120        (is_fake_stack && ptr[0] == kRetiredStackFrameMagic)) {
121      *offset = addr - (uintptr_t)ptr;
122      return (const char*)ptr[1];
123    }
124    ptr--;
125  }
126  *offset = 0;
127  return "UNKNOWN";
128}
129
130}  // namespace __asan
131