aboutsummaryrefslogtreecommitdiff
path: root/lib/asan/asan_thread.cc
blob: 05a41ea9685ae8b1035cf5083dc85bcbf880f312 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
//===-- asan_thread.cc ----------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of AddressSanitizer, an address sanity checker.
//
// Thread-related code.
//===----------------------------------------------------------------------===//
#include "asan_allocator.h"
#include "asan_interceptors.h"
#include "asan_stack.h"
#include "asan_thread.h"
#include "asan_thread_registry.h"
#include "asan_mapping.h"
#include "sanitizer_common/sanitizer_common.h"

namespace __asan {

AsanThread::AsanThread(LinkerInitialized x)
    : fake_stack_(x),
      malloc_storage_(x),
      stats_(x) { }

static AsanLock mu_for_thread_summary(LINKER_INITIALIZED);
static LowLevelAllocator allocator_for_thread_summary(LINKER_INITIALIZED);

AsanThread *AsanThread::Create(u32 parent_tid, thread_callback_t start_routine,
                               void *arg, AsanStackTrace *stack) {
  uptr size = RoundUpTo(sizeof(AsanThread), kPageSize);
  AsanThread *thread = (AsanThread*)MmapOrDie(size, __FUNCTION__);
  thread->start_routine_ = start_routine;
  thread->arg_ = arg;

  const uptr kSummaryAllocSize = 1024;
  CHECK_LE(sizeof(AsanThreadSummary), kSummaryAllocSize);
  AsanThreadSummary *summary;
  {
    ScopedLock lock(&mu_for_thread_summary);
    summary = (AsanThreadSummary*)
        allocator_for_thread_summary.Allocate(kSummaryAllocSize);
  }
  summary->Init(parent_tid, stack);
  summary->set_thread(thread);
  thread->set_summary(summary);

  return thread;
}

void AsanThreadSummary::TSDDtor(void *tsd) {
  AsanThreadSummary *summary = (AsanThreadSummary*)tsd;
  if (flags()->verbosity >= 1) {
    Report("T%d TSDDtor\n", summary->tid());
  }
  if (summary->thread()) {
    summary->thread()->Destroy();
  }
}

void AsanThread::Destroy() {
  if (flags()->verbosity >= 1) {
    Report("T%d exited\n", tid());
  }

  asanThreadRegistry().UnregisterThread(this);
  CHECK(summary()->thread() == 0);
  // We also clear the shadow on thread destruction because
  // some code may still be executing in later TSD destructors
  // and we don't want it to have any poisoned stack.
  ClearShadowForThreadStack();
  fake_stack().Cleanup();
  uptr size = RoundUpTo(sizeof(AsanThread), kPageSize);
  UnmapOrDie(this, size);
}

void AsanThread::Init() {
  SetThreadStackTopAndBottom();
  CHECK(AddrIsInMem(stack_bottom_));
  CHECK(AddrIsInMem(stack_top_));
  ClearShadowForThreadStack();
  if (flags()->verbosity >= 1) {
    int local = 0;
    Report("T%d: stack [%p,%p) size 0x%zx; local=%p\n",
           tid(), (void*)stack_bottom_, (void*)stack_top_,
           stack_top_ - stack_bottom_, &local);
  }
  fake_stack_.Init(stack_size());
  AsanPlatformThreadInit();
}

thread_return_t AsanThread::ThreadStart() {
  Init();
  if (flags()->use_sigaltstack) SetAlternateSignalStack();

  if (!start_routine_) {
    // start_routine_ == 0 if we're on the main thread or on one of the
    // OS X libdispatch worker threads. But nobody is supposed to call
    // ThreadStart() for the worker threads.
    CHECK(tid() == 0);
    return 0;
  }

  thread_return_t res = start_routine_(arg_);
  malloc_storage().CommitBack();
  if (flags()->use_sigaltstack) UnsetAlternateSignalStack();

  this->Destroy();

  return res;
}

void AsanThread::SetThreadStackTopAndBottom() {
  GetThreadStackTopAndBottom(tid() == 0, &stack_top_, &stack_bottom_);
  int local;
  CHECK(AddrIsInStack((uptr)&local));
}

void AsanThread::ClearShadowForThreadStack() {
  PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0);
}

const char *AsanThread::GetFrameNameByAddr(uptr addr, uptr *offset) {
  uptr bottom = 0;
  bool is_fake_stack = false;
  if (AddrIsInStack(addr)) {
    bottom = stack_bottom();
  } else {
    bottom = fake_stack().AddrIsInFakeStack(addr);
    CHECK(bottom);
    is_fake_stack = true;
  }
  uptr aligned_addr = addr & ~(__WORDSIZE/8 - 1);  // align addr.
  u8 *shadow_ptr = (u8*)MemToShadow(aligned_addr);
  u8 *shadow_bottom = (u8*)MemToShadow(bottom);

  while (shadow_ptr >= shadow_bottom &&
      *shadow_ptr != kAsanStackLeftRedzoneMagic) {
    shadow_ptr--;
  }

  while (shadow_ptr >= shadow_bottom &&
      *shadow_ptr == kAsanStackLeftRedzoneMagic) {
    shadow_ptr--;
  }

  if (shadow_ptr < shadow_bottom) {
    *offset = 0;
    return "UNKNOWN";
  }

  uptr* ptr = (uptr*)SHADOW_TO_MEM((uptr)(shadow_ptr + 1));
  CHECK((ptr[0] == kCurrentStackFrameMagic) ||
      (is_fake_stack && ptr[0] == kRetiredStackFrameMagic));
  *offset = addr - (uptr)ptr;
  return (const char*)ptr[1];
}

}  // namespace __asan