xref: /freebsd/contrib/llvm-project/compiler-rt/lib/hwasan/hwasan_thread.cpp (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1*0b57cec5SDimitry Andric 
2*0b57cec5SDimitry Andric #include "hwasan.h"
3*0b57cec5SDimitry Andric #include "hwasan_mapping.h"
4*0b57cec5SDimitry Andric #include "hwasan_thread.h"
5*0b57cec5SDimitry Andric #include "hwasan_poisoning.h"
6*0b57cec5SDimitry Andric #include "hwasan_interface_internal.h"
7*0b57cec5SDimitry Andric 
8*0b57cec5SDimitry Andric #include "sanitizer_common/sanitizer_file.h"
9*0b57cec5SDimitry Andric #include "sanitizer_common/sanitizer_placement_new.h"
10*0b57cec5SDimitry Andric #include "sanitizer_common/sanitizer_tls_get_addr.h"
11*0b57cec5SDimitry Andric 
12*0b57cec5SDimitry Andric 
13*0b57cec5SDimitry Andric namespace __hwasan {
14*0b57cec5SDimitry Andric 
15*0b57cec5SDimitry Andric static u32 RandomSeed() {
16*0b57cec5SDimitry Andric   u32 seed;
17*0b57cec5SDimitry Andric   do {
18*0b57cec5SDimitry Andric     if (UNLIKELY(!GetRandom(reinterpret_cast<void *>(&seed), sizeof(seed),
19*0b57cec5SDimitry Andric                             /*blocking=*/false))) {
20*0b57cec5SDimitry Andric       seed = static_cast<u32>(
21*0b57cec5SDimitry Andric           (NanoTime() >> 12) ^
22*0b57cec5SDimitry Andric           (reinterpret_cast<uptr>(__builtin_frame_address(0)) >> 4));
23*0b57cec5SDimitry Andric     }
24*0b57cec5SDimitry Andric   } while (!seed);
25*0b57cec5SDimitry Andric   return seed;
26*0b57cec5SDimitry Andric }
27*0b57cec5SDimitry Andric 
28*0b57cec5SDimitry Andric void Thread::InitRandomState() {
29*0b57cec5SDimitry Andric   random_state_ = flags()->random_tags ? RandomSeed() : unique_id_;
30*0b57cec5SDimitry Andric 
31*0b57cec5SDimitry Andric   // Push a random number of zeros onto the ring buffer so that the first stack
32*0b57cec5SDimitry Andric   // tag base will be random.
33*0b57cec5SDimitry Andric   for (tag_t i = 0, e = GenerateRandomTag(); i != e; ++i)
34*0b57cec5SDimitry Andric     stack_allocations_->push(0);
35*0b57cec5SDimitry Andric }
36*0b57cec5SDimitry Andric 
37*0b57cec5SDimitry Andric void Thread::Init(uptr stack_buffer_start, uptr stack_buffer_size) {
38*0b57cec5SDimitry Andric   static u64 unique_id;
39*0b57cec5SDimitry Andric   unique_id_ = unique_id++;
40*0b57cec5SDimitry Andric   if (auto sz = flags()->heap_history_size)
41*0b57cec5SDimitry Andric     heap_allocations_ = HeapAllocationsRingBuffer::New(sz);
42*0b57cec5SDimitry Andric 
43*0b57cec5SDimitry Andric   HwasanTSDThreadInit();  // Only needed with interceptors.
44*0b57cec5SDimitry Andric   uptr *ThreadLong = GetCurrentThreadLongPtr();
45*0b57cec5SDimitry Andric   // The following implicitly sets (this) as the current thread.
46*0b57cec5SDimitry Andric   stack_allocations_ = new (ThreadLong)
47*0b57cec5SDimitry Andric       StackAllocationsRingBuffer((void *)stack_buffer_start, stack_buffer_size);
48*0b57cec5SDimitry Andric   // Check that it worked.
49*0b57cec5SDimitry Andric   CHECK_EQ(GetCurrentThread(), this);
50*0b57cec5SDimitry Andric 
51*0b57cec5SDimitry Andric   // ScopedTaggingDisable needs GetCurrentThread to be set up.
52*0b57cec5SDimitry Andric   ScopedTaggingDisabler disabler;
53*0b57cec5SDimitry Andric 
54*0b57cec5SDimitry Andric   uptr tls_size;
55*0b57cec5SDimitry Andric   uptr stack_size;
56*0b57cec5SDimitry Andric   GetThreadStackAndTls(IsMainThread(), &stack_bottom_, &stack_size, &tls_begin_,
57*0b57cec5SDimitry Andric                        &tls_size);
58*0b57cec5SDimitry Andric   stack_top_ = stack_bottom_ + stack_size;
59*0b57cec5SDimitry Andric   tls_end_ = tls_begin_ + tls_size;
60*0b57cec5SDimitry Andric 
61*0b57cec5SDimitry Andric   if (stack_bottom_) {
62*0b57cec5SDimitry Andric     int local;
63*0b57cec5SDimitry Andric     CHECK(AddrIsInStack((uptr)&local));
64*0b57cec5SDimitry Andric     CHECK(MemIsApp(stack_bottom_));
65*0b57cec5SDimitry Andric     CHECK(MemIsApp(stack_top_ - 1));
66*0b57cec5SDimitry Andric   }
67*0b57cec5SDimitry Andric 
68*0b57cec5SDimitry Andric   if (flags()->verbose_threads) {
69*0b57cec5SDimitry Andric     if (IsMainThread()) {
70*0b57cec5SDimitry Andric       Printf("sizeof(Thread): %zd sizeof(HeapRB): %zd sizeof(StackRB): %zd\n",
71*0b57cec5SDimitry Andric              sizeof(Thread), heap_allocations_->SizeInBytes(),
72*0b57cec5SDimitry Andric              stack_allocations_->size() * sizeof(uptr));
73*0b57cec5SDimitry Andric     }
74*0b57cec5SDimitry Andric     Print("Creating  : ");
75*0b57cec5SDimitry Andric   }
76*0b57cec5SDimitry Andric }
77*0b57cec5SDimitry Andric 
78*0b57cec5SDimitry Andric void Thread::ClearShadowForThreadStackAndTLS() {
79*0b57cec5SDimitry Andric   if (stack_top_ != stack_bottom_)
80*0b57cec5SDimitry Andric     TagMemory(stack_bottom_, stack_top_ - stack_bottom_, 0);
81*0b57cec5SDimitry Andric   if (tls_begin_ != tls_end_)
82*0b57cec5SDimitry Andric     TagMemory(tls_begin_, tls_end_ - tls_begin_, 0);
83*0b57cec5SDimitry Andric }
84*0b57cec5SDimitry Andric 
85*0b57cec5SDimitry Andric void Thread::Destroy() {
86*0b57cec5SDimitry Andric   if (flags()->verbose_threads)
87*0b57cec5SDimitry Andric     Print("Destroying: ");
88*0b57cec5SDimitry Andric   AllocatorSwallowThreadLocalCache(allocator_cache());
89*0b57cec5SDimitry Andric   ClearShadowForThreadStackAndTLS();
90*0b57cec5SDimitry Andric   if (heap_allocations_)
91*0b57cec5SDimitry Andric     heap_allocations_->Delete();
92*0b57cec5SDimitry Andric   DTLS_Destroy();
93*0b57cec5SDimitry Andric }
94*0b57cec5SDimitry Andric 
95*0b57cec5SDimitry Andric void Thread::Print(const char *Prefix) {
96*0b57cec5SDimitry Andric   Printf("%sT%zd %p stack: [%p,%p) sz: %zd tls: [%p,%p)\n", Prefix,
97*0b57cec5SDimitry Andric          unique_id_, this, stack_bottom(), stack_top(),
98*0b57cec5SDimitry Andric          stack_top() - stack_bottom(),
99*0b57cec5SDimitry Andric          tls_begin(), tls_end());
100*0b57cec5SDimitry Andric }
101*0b57cec5SDimitry Andric 
102*0b57cec5SDimitry Andric static u32 xorshift(u32 state) {
103*0b57cec5SDimitry Andric   state ^= state << 13;
104*0b57cec5SDimitry Andric   state ^= state >> 17;
105*0b57cec5SDimitry Andric   state ^= state << 5;
106*0b57cec5SDimitry Andric   return state;
107*0b57cec5SDimitry Andric }
108*0b57cec5SDimitry Andric 
109*0b57cec5SDimitry Andric // Generate a (pseudo-)random non-zero tag.
110*0b57cec5SDimitry Andric tag_t Thread::GenerateRandomTag() {
111*0b57cec5SDimitry Andric   if (tagging_disabled_) return 0;
112*0b57cec5SDimitry Andric   tag_t tag;
113*0b57cec5SDimitry Andric   do {
114*0b57cec5SDimitry Andric     if (flags()->random_tags) {
115*0b57cec5SDimitry Andric       if (!random_buffer_)
116*0b57cec5SDimitry Andric         random_buffer_ = random_state_ = xorshift(random_state_);
117*0b57cec5SDimitry Andric       CHECK(random_buffer_);
118*0b57cec5SDimitry Andric       tag = random_buffer_ & 0xFF;
119*0b57cec5SDimitry Andric       random_buffer_ >>= 8;
120*0b57cec5SDimitry Andric     } else {
121*0b57cec5SDimitry Andric       tag = random_state_ = (random_state_ + 1) & 0xFF;
122*0b57cec5SDimitry Andric     }
123*0b57cec5SDimitry Andric   } while (!tag);
124*0b57cec5SDimitry Andric   return tag;
125*0b57cec5SDimitry Andric }
126*0b57cec5SDimitry Andric 
127*0b57cec5SDimitry Andric } // namespace __hwasan
128