1
2#include "msan.h"
3#include "msan_thread.h"
4#include "msan_interface_internal.h"
5
6#include "sanitizer_common/sanitizer_tls_get_addr.h"
7
8namespace __msan {
9
10MsanThread *MsanThread::Create(thread_callback_t start_routine,
11                               void *arg) {
12  uptr PageSize = GetPageSizeCached();
13  uptr size = RoundUpTo(sizeof(MsanThread), PageSize);
14  MsanThread *thread = (MsanThread*)MmapOrDie(size, __func__);
15  thread->start_routine_ = start_routine;
16  thread->arg_ = arg;
17  thread->destructor_iterations_ = GetPthreadDestructorIterations();
18
19  return thread;
20}
21
22void MsanThread::SetThreadStackAndTls() {
23  uptr tls_size = 0;
24  uptr stack_size = 0;
25  GetThreadStackAndTls(IsMainThread(), &stack_bottom_, &stack_size,
26                       &tls_begin_, &tls_size);
27  stack_top_ = stack_bottom_ + stack_size;
28  tls_end_ = tls_begin_ + tls_size;
29
30  int local;
31  CHECK(AddrIsInStack((uptr)&local));
32}
33
34void MsanThread::ClearShadowForThreadStackAndTLS() {
35  __msan_unpoison((void *)stack_bottom_, stack_top_ - stack_bottom_);
36  if (tls_begin_ != tls_end_)
37    __msan_unpoison((void *)tls_begin_, tls_end_ - tls_begin_);
38  DTLS *dtls = DTLS_Get();
39  CHECK_NE(dtls, 0);
40  for (uptr i = 0; i < dtls->dtv_size; ++i)
41    __msan_unpoison((void *)(dtls->dtv[i].beg), dtls->dtv[i].size);
42}
43
44void MsanThread::Init() {
45  SetThreadStackAndTls();
46  CHECK(MEM_IS_APP(stack_bottom_));
47  CHECK(MEM_IS_APP(stack_top_ - 1));
48  ClearShadowForThreadStackAndTLS();
49}
50
51void MsanThread::TSDDtor(void *tsd) {
52  MsanThread *t = (MsanThread*)tsd;
53  t->Destroy();
54}
55
56void MsanThread::Destroy() {
57  malloc_storage().CommitBack();
58  // We also clear the shadow on thread destruction because
59  // some code may still be executing in later TSD destructors
60  // and we don't want it to have any poisoned stack.
61  ClearShadowForThreadStackAndTLS();
62  uptr size = RoundUpTo(sizeof(MsanThread), GetPageSizeCached());
63  UnmapOrDie(this, size);
64  DTLS_Destroy();
65}
66
67thread_return_t MsanThread::ThreadStart() {
68  Init();
69
70  if (!start_routine_) {
71    // start_routine_ == 0 if we're on the main thread or on one of the
72    // OS X libdispatch worker threads. But nobody is supposed to call
73    // ThreadStart() for the worker threads.
74    return 0;
75  }
76
77  thread_return_t res = start_routine_(arg_);
78
79  return res;
80}
81
82} // namespace __msan
83