xref: /freebsd-src/contrib/llvm-project/compiler-rt/lib/asan/asan_thread.cpp (revision 0eae32dcef82f6f06de6419a0d623d7def0cc8f6)
168d75effSDimitry Andric //===-- asan_thread.cpp ---------------------------------------------------===//
268d75effSDimitry Andric //
368d75effSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
468d75effSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
568d75effSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
668d75effSDimitry Andric //
768d75effSDimitry Andric //===----------------------------------------------------------------------===//
868d75effSDimitry Andric //
968d75effSDimitry Andric // This file is a part of AddressSanitizer, an address sanity checker.
1068d75effSDimitry Andric //
1168d75effSDimitry Andric // Thread-related code.
1268d75effSDimitry Andric //===----------------------------------------------------------------------===//
1368d75effSDimitry Andric #include "asan_allocator.h"
1468d75effSDimitry Andric #include "asan_interceptors.h"
1568d75effSDimitry Andric #include "asan_poisoning.h"
1668d75effSDimitry Andric #include "asan_stack.h"
1768d75effSDimitry Andric #include "asan_thread.h"
1868d75effSDimitry Andric #include "asan_mapping.h"
1968d75effSDimitry Andric #include "sanitizer_common/sanitizer_common.h"
2068d75effSDimitry Andric #include "sanitizer_common/sanitizer_placement_new.h"
2168d75effSDimitry Andric #include "sanitizer_common/sanitizer_stackdepot.h"
2268d75effSDimitry Andric #include "sanitizer_common/sanitizer_tls_get_addr.h"
2368d75effSDimitry Andric #include "lsan/lsan_common.h"
2468d75effSDimitry Andric 
2568d75effSDimitry Andric namespace __asan {
2668d75effSDimitry Andric 
2768d75effSDimitry Andric // AsanThreadContext implementation.
2868d75effSDimitry Andric 
2968d75effSDimitry Andric void AsanThreadContext::OnCreated(void *arg) {
3068d75effSDimitry Andric   CreateThreadContextArgs *args = static_cast<CreateThreadContextArgs*>(arg);
3168d75effSDimitry Andric   if (args->stack)
3268d75effSDimitry Andric     stack_id = StackDepotPut(*args->stack);
3368d75effSDimitry Andric   thread = args->thread;
3468d75effSDimitry Andric   thread->set_context(this);
3568d75effSDimitry Andric }
3668d75effSDimitry Andric 
3768d75effSDimitry Andric void AsanThreadContext::OnFinished() {
3868d75effSDimitry Andric   // Drop the link to the AsanThread object.
3968d75effSDimitry Andric   thread = nullptr;
4068d75effSDimitry Andric }
4168d75effSDimitry Andric 
4268d75effSDimitry Andric // MIPS requires aligned address
4368d75effSDimitry Andric static ALIGNED(16) char thread_registry_placeholder[sizeof(ThreadRegistry)];
4468d75effSDimitry Andric static ThreadRegistry *asan_thread_registry;
4568d75effSDimitry Andric 
46349cc55cSDimitry Andric static Mutex mu_for_thread_context;
4768d75effSDimitry Andric static LowLevelAllocator allocator_for_thread_context;
4868d75effSDimitry Andric 
4968d75effSDimitry Andric static ThreadContextBase *GetAsanThreadContext(u32 tid) {
50349cc55cSDimitry Andric   Lock lock(&mu_for_thread_context);
5168d75effSDimitry Andric   return new(allocator_for_thread_context) AsanThreadContext(tid);
5268d75effSDimitry Andric }
5368d75effSDimitry Andric 
5468d75effSDimitry Andric ThreadRegistry &asanThreadRegistry() {
5568d75effSDimitry Andric   static bool initialized;
5668d75effSDimitry Andric   // Don't worry about thread_safety - this should be called when there is
5768d75effSDimitry Andric   // a single thread.
5868d75effSDimitry Andric   if (!initialized) {
5968d75effSDimitry Andric     // Never reuse ASan threads: we store pointer to AsanThreadContext
6068d75effSDimitry Andric     // in TSD and can't reliably tell when no more TSD destructors will
6168d75effSDimitry Andric     // be called. It would be wrong to reuse AsanThreadContext for another
6268d75effSDimitry Andric     // thread before all TSD destructors will be called for it.
63fe6060f1SDimitry Andric     asan_thread_registry =
64fe6060f1SDimitry Andric         new (thread_registry_placeholder) ThreadRegistry(GetAsanThreadContext);
6568d75effSDimitry Andric     initialized = true;
6668d75effSDimitry Andric   }
6768d75effSDimitry Andric   return *asan_thread_registry;
6868d75effSDimitry Andric }
6968d75effSDimitry Andric 
7068d75effSDimitry Andric AsanThreadContext *GetThreadContextByTidLocked(u32 tid) {
7168d75effSDimitry Andric   return static_cast<AsanThreadContext *>(
7268d75effSDimitry Andric       asanThreadRegistry().GetThreadLocked(tid));
7368d75effSDimitry Andric }
7468d75effSDimitry Andric 
7568d75effSDimitry Andric // AsanThread implementation.
7668d75effSDimitry Andric 
7768d75effSDimitry Andric AsanThread *AsanThread::Create(thread_callback_t start_routine, void *arg,
7868d75effSDimitry Andric                                u32 parent_tid, StackTrace *stack,
7968d75effSDimitry Andric                                bool detached) {
8068d75effSDimitry Andric   uptr PageSize = GetPageSizeCached();
8168d75effSDimitry Andric   uptr size = RoundUpTo(sizeof(AsanThread), PageSize);
8268d75effSDimitry Andric   AsanThread *thread = (AsanThread*)MmapOrDie(size, __func__);
8368d75effSDimitry Andric   thread->start_routine_ = start_routine;
8468d75effSDimitry Andric   thread->arg_ = arg;
8568d75effSDimitry Andric   AsanThreadContext::CreateThreadContextArgs args = {thread, stack};
86349cc55cSDimitry Andric   asanThreadRegistry().CreateThread(0, detached, parent_tid, &args);
8768d75effSDimitry Andric 
8868d75effSDimitry Andric   return thread;
8968d75effSDimitry Andric }
9068d75effSDimitry Andric 
9168d75effSDimitry Andric void AsanThread::TSDDtor(void *tsd) {
9268d75effSDimitry Andric   AsanThreadContext *context = (AsanThreadContext*)tsd;
9368d75effSDimitry Andric   VReport(1, "T%d TSDDtor\n", context->tid);
9468d75effSDimitry Andric   if (context->thread)
9568d75effSDimitry Andric     context->thread->Destroy();
9668d75effSDimitry Andric }
9768d75effSDimitry Andric 
9868d75effSDimitry Andric void AsanThread::Destroy() {
9968d75effSDimitry Andric   int tid = this->tid();
10068d75effSDimitry Andric   VReport(1, "T%d exited\n", tid);
10168d75effSDimitry Andric 
102fe6060f1SDimitry Andric   bool was_running =
103fe6060f1SDimitry Andric       (asanThreadRegistry().FinishThread(tid) == ThreadStatusRunning);
104fe6060f1SDimitry Andric   if (was_running) {
105fe6060f1SDimitry Andric     if (AsanThread *thread = GetCurrentThread())
106fe6060f1SDimitry Andric       CHECK_EQ(this, thread);
10768d75effSDimitry Andric     malloc_storage().CommitBack();
108fe6060f1SDimitry Andric     if (common_flags()->use_sigaltstack)
109fe6060f1SDimitry Andric       UnsetAlternateSignalStack();
11068d75effSDimitry Andric     FlushToDeadThreadStats(&stats_);
11168d75effSDimitry Andric     // We also clear the shadow on thread destruction because
11268d75effSDimitry Andric     // some code may still be executing in later TSD destructors
11368d75effSDimitry Andric     // and we don't want it to have any poisoned stack.
11468d75effSDimitry Andric     ClearShadowForThreadStackAndTLS();
11568d75effSDimitry Andric     DeleteFakeStack(tid);
116fe6060f1SDimitry Andric   } else {
117fe6060f1SDimitry Andric     CHECK_NE(this, GetCurrentThread());
118fe6060f1SDimitry Andric   }
11968d75effSDimitry Andric   uptr size = RoundUpTo(sizeof(AsanThread), GetPageSizeCached());
12068d75effSDimitry Andric   UnmapOrDie(this, size);
121fe6060f1SDimitry Andric   if (was_running)
12268d75effSDimitry Andric     DTLS_Destroy();
12368d75effSDimitry Andric }
12468d75effSDimitry Andric 
12568d75effSDimitry Andric void AsanThread::StartSwitchFiber(FakeStack **fake_stack_save, uptr bottom,
12668d75effSDimitry Andric                                   uptr size) {
12768d75effSDimitry Andric   if (atomic_load(&stack_switching_, memory_order_relaxed)) {
12868d75effSDimitry Andric     Report("ERROR: starting fiber switch while in fiber switch\n");
12968d75effSDimitry Andric     Die();
13068d75effSDimitry Andric   }
13168d75effSDimitry Andric 
13268d75effSDimitry Andric   next_stack_bottom_ = bottom;
13368d75effSDimitry Andric   next_stack_top_ = bottom + size;
13468d75effSDimitry Andric   atomic_store(&stack_switching_, 1, memory_order_release);
13568d75effSDimitry Andric 
13668d75effSDimitry Andric   FakeStack *current_fake_stack = fake_stack_;
13768d75effSDimitry Andric   if (fake_stack_save)
13868d75effSDimitry Andric     *fake_stack_save = fake_stack_;
13968d75effSDimitry Andric   fake_stack_ = nullptr;
14068d75effSDimitry Andric   SetTLSFakeStack(nullptr);
14168d75effSDimitry Andric   // if fake_stack_save is null, the fiber will die, delete the fakestack
14268d75effSDimitry Andric   if (!fake_stack_save && current_fake_stack)
14368d75effSDimitry Andric     current_fake_stack->Destroy(this->tid());
14468d75effSDimitry Andric }
14568d75effSDimitry Andric 
14668d75effSDimitry Andric void AsanThread::FinishSwitchFiber(FakeStack *fake_stack_save,
14768d75effSDimitry Andric                                    uptr *bottom_old,
14868d75effSDimitry Andric                                    uptr *size_old) {
14968d75effSDimitry Andric   if (!atomic_load(&stack_switching_, memory_order_relaxed)) {
15068d75effSDimitry Andric     Report("ERROR: finishing a fiber switch that has not started\n");
15168d75effSDimitry Andric     Die();
15268d75effSDimitry Andric   }
15368d75effSDimitry Andric 
15468d75effSDimitry Andric   if (fake_stack_save) {
15568d75effSDimitry Andric     SetTLSFakeStack(fake_stack_save);
15668d75effSDimitry Andric     fake_stack_ = fake_stack_save;
15768d75effSDimitry Andric   }
15868d75effSDimitry Andric 
15968d75effSDimitry Andric   if (bottom_old)
16068d75effSDimitry Andric     *bottom_old = stack_bottom_;
16168d75effSDimitry Andric   if (size_old)
16268d75effSDimitry Andric     *size_old = stack_top_ - stack_bottom_;
16368d75effSDimitry Andric   stack_bottom_ = next_stack_bottom_;
16468d75effSDimitry Andric   stack_top_ = next_stack_top_;
16568d75effSDimitry Andric   atomic_store(&stack_switching_, 0, memory_order_release);
16668d75effSDimitry Andric   next_stack_top_ = 0;
16768d75effSDimitry Andric   next_stack_bottom_ = 0;
16868d75effSDimitry Andric }
16968d75effSDimitry Andric 
17068d75effSDimitry Andric inline AsanThread::StackBounds AsanThread::GetStackBounds() const {
17168d75effSDimitry Andric   if (!atomic_load(&stack_switching_, memory_order_acquire)) {
17268d75effSDimitry Andric     // Make sure the stack bounds are fully initialized.
17368d75effSDimitry Andric     if (stack_bottom_ >= stack_top_) return {0, 0};
17468d75effSDimitry Andric     return {stack_bottom_, stack_top_};
17568d75effSDimitry Andric   }
17668d75effSDimitry Andric   char local;
17768d75effSDimitry Andric   const uptr cur_stack = (uptr)&local;
17868d75effSDimitry Andric   // Note: need to check next stack first, because FinishSwitchFiber
17968d75effSDimitry Andric   // may be in process of overwriting stack_top_/bottom_. But in such case
18068d75effSDimitry Andric   // we are already on the next stack.
18168d75effSDimitry Andric   if (cur_stack >= next_stack_bottom_ && cur_stack < next_stack_top_)
18268d75effSDimitry Andric     return {next_stack_bottom_, next_stack_top_};
18368d75effSDimitry Andric   return {stack_bottom_, stack_top_};
18468d75effSDimitry Andric }
18568d75effSDimitry Andric 
18668d75effSDimitry Andric uptr AsanThread::stack_top() {
18768d75effSDimitry Andric   return GetStackBounds().top;
18868d75effSDimitry Andric }
18968d75effSDimitry Andric 
19068d75effSDimitry Andric uptr AsanThread::stack_bottom() {
19168d75effSDimitry Andric   return GetStackBounds().bottom;
19268d75effSDimitry Andric }
19368d75effSDimitry Andric 
19468d75effSDimitry Andric uptr AsanThread::stack_size() {
19568d75effSDimitry Andric   const auto bounds = GetStackBounds();
19668d75effSDimitry Andric   return bounds.top - bounds.bottom;
19768d75effSDimitry Andric }
19868d75effSDimitry Andric 
199e8d8bef9SDimitry Andric // We want to create the FakeStack lazily on the first use, but not earlier
20068d75effSDimitry Andric // than the stack size is known and the procedure has to be async-signal safe.
20168d75effSDimitry Andric FakeStack *AsanThread::AsyncSignalSafeLazyInitFakeStack() {
20268d75effSDimitry Andric   uptr stack_size = this->stack_size();
20368d75effSDimitry Andric   if (stack_size == 0)  // stack_size is not yet available, don't use FakeStack.
20468d75effSDimitry Andric     return nullptr;
20568d75effSDimitry Andric   uptr old_val = 0;
20668d75effSDimitry Andric   // fake_stack_ has 3 states:
20768d75effSDimitry Andric   // 0   -- not initialized
20868d75effSDimitry Andric   // 1   -- being initialized
20968d75effSDimitry Andric   // ptr -- initialized
21068d75effSDimitry Andric   // This CAS checks if the state was 0 and if so changes it to state 1,
21168d75effSDimitry Andric   // if that was successful, it initializes the pointer.
21268d75effSDimitry Andric   if (atomic_compare_exchange_strong(
21368d75effSDimitry Andric       reinterpret_cast<atomic_uintptr_t *>(&fake_stack_), &old_val, 1UL,
21468d75effSDimitry Andric       memory_order_relaxed)) {
21568d75effSDimitry Andric     uptr stack_size_log = Log2(RoundUpToPowerOfTwo(stack_size));
21668d75effSDimitry Andric     CHECK_LE(flags()->min_uar_stack_size_log, flags()->max_uar_stack_size_log);
21768d75effSDimitry Andric     stack_size_log =
21868d75effSDimitry Andric         Min(stack_size_log, static_cast<uptr>(flags()->max_uar_stack_size_log));
21968d75effSDimitry Andric     stack_size_log =
22068d75effSDimitry Andric         Max(stack_size_log, static_cast<uptr>(flags()->min_uar_stack_size_log));
22168d75effSDimitry Andric     fake_stack_ = FakeStack::Create(stack_size_log);
222e8d8bef9SDimitry Andric     DCHECK_EQ(GetCurrentThread(), this);
22368d75effSDimitry Andric     SetTLSFakeStack(fake_stack_);
22468d75effSDimitry Andric     return fake_stack_;
22568d75effSDimitry Andric   }
22668d75effSDimitry Andric   return nullptr;
22768d75effSDimitry Andric }
22868d75effSDimitry Andric 
22968d75effSDimitry Andric void AsanThread::Init(const InitOptions *options) {
230fe6060f1SDimitry Andric   DCHECK_NE(tid(), kInvalidTid);
23168d75effSDimitry Andric   next_stack_top_ = next_stack_bottom_ = 0;
23268d75effSDimitry Andric   atomic_store(&stack_switching_, false, memory_order_release);
23368d75effSDimitry Andric   CHECK_EQ(this->stack_size(), 0U);
23468d75effSDimitry Andric   SetThreadStackAndTls(options);
23568d75effSDimitry Andric   if (stack_top_ != stack_bottom_) {
23668d75effSDimitry Andric     CHECK_GT(this->stack_size(), 0U);
23768d75effSDimitry Andric     CHECK(AddrIsInMem(stack_bottom_));
23868d75effSDimitry Andric     CHECK(AddrIsInMem(stack_top_ - 1));
23968d75effSDimitry Andric   }
24068d75effSDimitry Andric   ClearShadowForThreadStackAndTLS();
24168d75effSDimitry Andric   fake_stack_ = nullptr;
242e8d8bef9SDimitry Andric   if (__asan_option_detect_stack_use_after_return &&
243e8d8bef9SDimitry Andric       tid() == GetCurrentTidOrInvalid()) {
244e8d8bef9SDimitry Andric     // AsyncSignalSafeLazyInitFakeStack makes use of threadlocals and must be
245e8d8bef9SDimitry Andric     // called from the context of the thread it is initializing, not its parent.
246e8d8bef9SDimitry Andric     // Most platforms call AsanThread::Init on the newly-spawned thread, but
247e8d8bef9SDimitry Andric     // Fuchsia calls this function from the parent thread.  To support that
248e8d8bef9SDimitry Andric     // approach, we avoid calling AsyncSignalSafeLazyInitFakeStack here; it will
249e8d8bef9SDimitry Andric     // be called by the new thread when it first attempts to access the fake
250e8d8bef9SDimitry Andric     // stack.
25168d75effSDimitry Andric     AsyncSignalSafeLazyInitFakeStack();
252e8d8bef9SDimitry Andric   }
25368d75effSDimitry Andric   int local = 0;
25468d75effSDimitry Andric   VReport(1, "T%d: stack [%p,%p) size 0x%zx; local=%p\n", tid(),
25568d75effSDimitry Andric           (void *)stack_bottom_, (void *)stack_top_, stack_top_ - stack_bottom_,
256349cc55cSDimitry Andric           (void *)&local);
25768d75effSDimitry Andric }
25868d75effSDimitry Andric 
259fe6060f1SDimitry Andric // Fuchsia doesn't use ThreadStart.
260fe6060f1SDimitry Andric // asan_fuchsia.c definies CreateMainThread and SetThreadStackAndTls.
261fe6060f1SDimitry Andric #if !SANITIZER_FUCHSIA
26268d75effSDimitry Andric 
263e8d8bef9SDimitry Andric thread_return_t AsanThread::ThreadStart(tid_t os_id) {
26468d75effSDimitry Andric   Init();
26568d75effSDimitry Andric   asanThreadRegistry().StartThread(tid(), os_id, ThreadType::Regular, nullptr);
26668d75effSDimitry Andric 
26768d75effSDimitry Andric   if (common_flags()->use_sigaltstack) SetAlternateSignalStack();
26868d75effSDimitry Andric 
26968d75effSDimitry Andric   if (!start_routine_) {
27068d75effSDimitry Andric     // start_routine_ == 0 if we're on the main thread or on one of the
27168d75effSDimitry Andric     // OS X libdispatch worker threads. But nobody is supposed to call
27268d75effSDimitry Andric     // ThreadStart() for the worker threads.
27368d75effSDimitry Andric     CHECK_EQ(tid(), 0);
27468d75effSDimitry Andric     return 0;
27568d75effSDimitry Andric   }
27668d75effSDimitry Andric 
27768d75effSDimitry Andric   thread_return_t res = start_routine_(arg_);
27868d75effSDimitry Andric 
27968d75effSDimitry Andric   // On POSIX systems we defer this to the TSD destructor. LSan will consider
28068d75effSDimitry Andric   // the thread's memory as non-live from the moment we call Destroy(), even
28168d75effSDimitry Andric   // though that memory might contain pointers to heap objects which will be
28268d75effSDimitry Andric   // cleaned up by a user-defined TSD destructor. Thus, calling Destroy() before
28368d75effSDimitry Andric   // the TSD destructors have run might cause false positives in LSan.
28468d75effSDimitry Andric   if (!SANITIZER_POSIX)
28568d75effSDimitry Andric     this->Destroy();
28668d75effSDimitry Andric 
28768d75effSDimitry Andric   return res;
28868d75effSDimitry Andric }
28968d75effSDimitry Andric 
29068d75effSDimitry Andric AsanThread *CreateMainThread() {
29168d75effSDimitry Andric   AsanThread *main_thread = AsanThread::Create(
292fe6060f1SDimitry Andric       /* start_routine */ nullptr, /* arg */ nullptr, /* parent_tid */ kMainTid,
29368d75effSDimitry Andric       /* stack */ nullptr, /* detached */ true);
29468d75effSDimitry Andric   SetCurrentThread(main_thread);
295e8d8bef9SDimitry Andric   main_thread->ThreadStart(internal_getpid());
29668d75effSDimitry Andric   return main_thread;
29768d75effSDimitry Andric }
29868d75effSDimitry Andric 
29968d75effSDimitry Andric // This implementation doesn't use the argument, which is just passed down
30068d75effSDimitry Andric // from the caller of Init (which see, above).  It's only there to support
30168d75effSDimitry Andric // OS-specific implementations that need more information passed through.
30268d75effSDimitry Andric void AsanThread::SetThreadStackAndTls(const InitOptions *options) {
30368d75effSDimitry Andric   DCHECK_EQ(options, nullptr);
30468d75effSDimitry Andric   uptr tls_size = 0;
30568d75effSDimitry Andric   uptr stack_size = 0;
306fe6060f1SDimitry Andric   GetThreadStackAndTls(tid() == kMainTid, &stack_bottom_, &stack_size,
307fe6060f1SDimitry Andric                        &tls_begin_, &tls_size);
308*0eae32dcSDimitry Andric   stack_top_ = RoundDownTo(stack_bottom_ + stack_size, ASAN_SHADOW_GRANULARITY);
30968d75effSDimitry Andric   tls_end_ = tls_begin_ + tls_size;
31068d75effSDimitry Andric   dtls_ = DTLS_Get();
31168d75effSDimitry Andric 
31268d75effSDimitry Andric   if (stack_top_ != stack_bottom_) {
31368d75effSDimitry Andric     int local;
31468d75effSDimitry Andric     CHECK(AddrIsInStack((uptr)&local));
31568d75effSDimitry Andric   }
31668d75effSDimitry Andric }
31768d75effSDimitry Andric 
318fe6060f1SDimitry Andric #endif  // !SANITIZER_FUCHSIA
31968d75effSDimitry Andric 
32068d75effSDimitry Andric void AsanThread::ClearShadowForThreadStackAndTLS() {
32168d75effSDimitry Andric   if (stack_top_ != stack_bottom_)
32268d75effSDimitry Andric     PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0);
32368d75effSDimitry Andric   if (tls_begin_ != tls_end_) {
324*0eae32dcSDimitry Andric     uptr tls_begin_aligned = RoundDownTo(tls_begin_, ASAN_SHADOW_GRANULARITY);
325*0eae32dcSDimitry Andric     uptr tls_end_aligned = RoundUpTo(tls_end_, ASAN_SHADOW_GRANULARITY);
32668d75effSDimitry Andric     FastPoisonShadowPartialRightRedzone(tls_begin_aligned,
32768d75effSDimitry Andric                                         tls_end_ - tls_begin_aligned,
32868d75effSDimitry Andric                                         tls_end_aligned - tls_end_, 0);
32968d75effSDimitry Andric   }
33068d75effSDimitry Andric }
33168d75effSDimitry Andric 
33268d75effSDimitry Andric bool AsanThread::GetStackFrameAccessByAddr(uptr addr,
33368d75effSDimitry Andric                                            StackFrameAccess *access) {
33468d75effSDimitry Andric   if (stack_top_ == stack_bottom_)
33568d75effSDimitry Andric     return false;
33668d75effSDimitry Andric 
33768d75effSDimitry Andric   uptr bottom = 0;
33868d75effSDimitry Andric   if (AddrIsInStack(addr)) {
33968d75effSDimitry Andric     bottom = stack_bottom();
340fe6060f1SDimitry Andric   } else if (FakeStack *fake_stack = get_fake_stack()) {
341fe6060f1SDimitry Andric     bottom = fake_stack->AddrIsInFakeStack(addr);
34268d75effSDimitry Andric     CHECK(bottom);
34368d75effSDimitry Andric     access->offset = addr - bottom;
34468d75effSDimitry Andric     access->frame_pc = ((uptr*)bottom)[2];
34568d75effSDimitry Andric     access->frame_descr = (const char *)((uptr*)bottom)[1];
34668d75effSDimitry Andric     return true;
34768d75effSDimitry Andric   }
34868d75effSDimitry Andric   uptr aligned_addr = RoundDownTo(addr, SANITIZER_WORDSIZE / 8);  // align addr.
349*0eae32dcSDimitry Andric   uptr mem_ptr = RoundDownTo(aligned_addr, ASAN_SHADOW_GRANULARITY);
35068d75effSDimitry Andric   u8 *shadow_ptr = (u8*)MemToShadow(aligned_addr);
35168d75effSDimitry Andric   u8 *shadow_bottom = (u8*)MemToShadow(bottom);
35268d75effSDimitry Andric 
35368d75effSDimitry Andric   while (shadow_ptr >= shadow_bottom &&
35468d75effSDimitry Andric          *shadow_ptr != kAsanStackLeftRedzoneMagic) {
35568d75effSDimitry Andric     shadow_ptr--;
356*0eae32dcSDimitry Andric     mem_ptr -= ASAN_SHADOW_GRANULARITY;
35768d75effSDimitry Andric   }
35868d75effSDimitry Andric 
35968d75effSDimitry Andric   while (shadow_ptr >= shadow_bottom &&
36068d75effSDimitry Andric          *shadow_ptr == kAsanStackLeftRedzoneMagic) {
36168d75effSDimitry Andric     shadow_ptr--;
362*0eae32dcSDimitry Andric     mem_ptr -= ASAN_SHADOW_GRANULARITY;
36368d75effSDimitry Andric   }
36468d75effSDimitry Andric 
36568d75effSDimitry Andric   if (shadow_ptr < shadow_bottom) {
36668d75effSDimitry Andric     return false;
36768d75effSDimitry Andric   }
36868d75effSDimitry Andric 
369*0eae32dcSDimitry Andric   uptr *ptr = (uptr *)(mem_ptr + ASAN_SHADOW_GRANULARITY);
37068d75effSDimitry Andric   CHECK(ptr[0] == kCurrentStackFrameMagic);
37168d75effSDimitry Andric   access->offset = addr - (uptr)ptr;
37268d75effSDimitry Andric   access->frame_pc = ptr[2];
37368d75effSDimitry Andric   access->frame_descr = (const char*)ptr[1];
37468d75effSDimitry Andric   return true;
37568d75effSDimitry Andric }
37668d75effSDimitry Andric 
37768d75effSDimitry Andric uptr AsanThread::GetStackVariableShadowStart(uptr addr) {
37868d75effSDimitry Andric   uptr bottom = 0;
37968d75effSDimitry Andric   if (AddrIsInStack(addr)) {
38068d75effSDimitry Andric     bottom = stack_bottom();
381fe6060f1SDimitry Andric   } else if (FakeStack *fake_stack = get_fake_stack()) {
382fe6060f1SDimitry Andric     bottom = fake_stack->AddrIsInFakeStack(addr);
383e8d8bef9SDimitry Andric     if (bottom == 0) {
384e8d8bef9SDimitry Andric       return 0;
385e8d8bef9SDimitry Andric     }
38668d75effSDimitry Andric   } else {
38768d75effSDimitry Andric     return 0;
38868d75effSDimitry Andric   }
38968d75effSDimitry Andric 
39068d75effSDimitry Andric   uptr aligned_addr = RoundDownTo(addr, SANITIZER_WORDSIZE / 8);  // align addr.
39168d75effSDimitry Andric   u8 *shadow_ptr = (u8*)MemToShadow(aligned_addr);
39268d75effSDimitry Andric   u8 *shadow_bottom = (u8*)MemToShadow(bottom);
39368d75effSDimitry Andric 
39468d75effSDimitry Andric   while (shadow_ptr >= shadow_bottom &&
39568d75effSDimitry Andric          (*shadow_ptr != kAsanStackLeftRedzoneMagic &&
39668d75effSDimitry Andric           *shadow_ptr != kAsanStackMidRedzoneMagic &&
39768d75effSDimitry Andric           *shadow_ptr != kAsanStackRightRedzoneMagic))
39868d75effSDimitry Andric     shadow_ptr--;
39968d75effSDimitry Andric 
40068d75effSDimitry Andric   return (uptr)shadow_ptr + 1;
40168d75effSDimitry Andric }
40268d75effSDimitry Andric 
40368d75effSDimitry Andric bool AsanThread::AddrIsInStack(uptr addr) {
40468d75effSDimitry Andric   const auto bounds = GetStackBounds();
40568d75effSDimitry Andric   return addr >= bounds.bottom && addr < bounds.top;
40668d75effSDimitry Andric }
40768d75effSDimitry Andric 
40868d75effSDimitry Andric static bool ThreadStackContainsAddress(ThreadContextBase *tctx_base,
40968d75effSDimitry Andric                                        void *addr) {
41068d75effSDimitry Andric   AsanThreadContext *tctx = static_cast<AsanThreadContext *>(tctx_base);
41168d75effSDimitry Andric   AsanThread *t = tctx->thread;
412fe6060f1SDimitry Andric   if (!t)
41368d75effSDimitry Andric     return false;
414fe6060f1SDimitry Andric   if (t->AddrIsInStack((uptr)addr))
415fe6060f1SDimitry Andric     return true;
416fe6060f1SDimitry Andric   FakeStack *fake_stack = t->get_fake_stack();
417fe6060f1SDimitry Andric   if (!fake_stack)
418fe6060f1SDimitry Andric     return false;
419fe6060f1SDimitry Andric   return fake_stack->AddrIsInFakeStack((uptr)addr);
42068d75effSDimitry Andric }
42168d75effSDimitry Andric 
42268d75effSDimitry Andric AsanThread *GetCurrentThread() {
42368d75effSDimitry Andric   AsanThreadContext *context =
42468d75effSDimitry Andric       reinterpret_cast<AsanThreadContext *>(AsanTSDGet());
42568d75effSDimitry Andric   if (!context) {
42668d75effSDimitry Andric     if (SANITIZER_ANDROID) {
42768d75effSDimitry Andric       // On Android, libc constructor is called _after_ asan_init, and cleans up
42868d75effSDimitry Andric       // TSD. Try to figure out if this is still the main thread by the stack
42968d75effSDimitry Andric       // address. We are not entirely sure that we have correct main thread
43068d75effSDimitry Andric       // limits, so only do this magic on Android, and only if the found thread
43168d75effSDimitry Andric       // is the main thread.
432fe6060f1SDimitry Andric       AsanThreadContext *tctx = GetThreadContextByTidLocked(kMainTid);
43368d75effSDimitry Andric       if (tctx && ThreadStackContainsAddress(tctx, &context)) {
43468d75effSDimitry Andric         SetCurrentThread(tctx->thread);
43568d75effSDimitry Andric         return tctx->thread;
43668d75effSDimitry Andric       }
43768d75effSDimitry Andric     }
43868d75effSDimitry Andric     return nullptr;
43968d75effSDimitry Andric   }
44068d75effSDimitry Andric   return context->thread;
44168d75effSDimitry Andric }
44268d75effSDimitry Andric 
44368d75effSDimitry Andric void SetCurrentThread(AsanThread *t) {
44468d75effSDimitry Andric   CHECK(t->context());
445349cc55cSDimitry Andric   VReport(2, "SetCurrentThread: %p for thread %p\n", (void *)t->context(),
44668d75effSDimitry Andric           (void *)GetThreadSelf());
44768d75effSDimitry Andric   // Make sure we do not reset the current AsanThread.
44868d75effSDimitry Andric   CHECK_EQ(0, AsanTSDGet());
44968d75effSDimitry Andric   AsanTSDSet(t->context());
45068d75effSDimitry Andric   CHECK_EQ(t->context(), AsanTSDGet());
45168d75effSDimitry Andric }
45268d75effSDimitry Andric 
45368d75effSDimitry Andric u32 GetCurrentTidOrInvalid() {
45468d75effSDimitry Andric   AsanThread *t = GetCurrentThread();
45568d75effSDimitry Andric   return t ? t->tid() : kInvalidTid;
45668d75effSDimitry Andric }
45768d75effSDimitry Andric 
45868d75effSDimitry Andric AsanThread *FindThreadByStackAddress(uptr addr) {
45968d75effSDimitry Andric   asanThreadRegistry().CheckLocked();
46068d75effSDimitry Andric   AsanThreadContext *tctx = static_cast<AsanThreadContext *>(
46168d75effSDimitry Andric       asanThreadRegistry().FindThreadContextLocked(ThreadStackContainsAddress,
46268d75effSDimitry Andric                                                    (void *)addr));
46368d75effSDimitry Andric   return tctx ? tctx->thread : nullptr;
46468d75effSDimitry Andric }
46568d75effSDimitry Andric 
46668d75effSDimitry Andric void EnsureMainThreadIDIsCorrect() {
46768d75effSDimitry Andric   AsanThreadContext *context =
46868d75effSDimitry Andric       reinterpret_cast<AsanThreadContext *>(AsanTSDGet());
469fe6060f1SDimitry Andric   if (context && (context->tid == kMainTid))
47068d75effSDimitry Andric     context->os_id = GetTid();
47168d75effSDimitry Andric }
47268d75effSDimitry Andric 
47368d75effSDimitry Andric __asan::AsanThread *GetAsanThreadByOsIDLocked(tid_t os_id) {
47468d75effSDimitry Andric   __asan::AsanThreadContext *context = static_cast<__asan::AsanThreadContext *>(
47568d75effSDimitry Andric       __asan::asanThreadRegistry().FindThreadContextByOsIDLocked(os_id));
47668d75effSDimitry Andric   if (!context) return nullptr;
47768d75effSDimitry Andric   return context->thread;
47868d75effSDimitry Andric }
47968d75effSDimitry Andric } // namespace __asan
48068d75effSDimitry Andric 
48168d75effSDimitry Andric // --- Implementation of LSan-specific functions --- {{{1
48268d75effSDimitry Andric namespace __lsan {
48368d75effSDimitry Andric bool GetThreadRangesLocked(tid_t os_id, uptr *stack_begin, uptr *stack_end,
48468d75effSDimitry Andric                            uptr *tls_begin, uptr *tls_end, uptr *cache_begin,
48568d75effSDimitry Andric                            uptr *cache_end, DTLS **dtls) {
48668d75effSDimitry Andric   __asan::AsanThread *t = __asan::GetAsanThreadByOsIDLocked(os_id);
48768d75effSDimitry Andric   if (!t) return false;
48868d75effSDimitry Andric   *stack_begin = t->stack_bottom();
48968d75effSDimitry Andric   *stack_end = t->stack_top();
49068d75effSDimitry Andric   *tls_begin = t->tls_begin();
49168d75effSDimitry Andric   *tls_end = t->tls_end();
49268d75effSDimitry Andric   // ASan doesn't keep allocator caches in TLS, so these are unused.
49368d75effSDimitry Andric   *cache_begin = 0;
49468d75effSDimitry Andric   *cache_end = 0;
49568d75effSDimitry Andric   *dtls = t->dtls();
49668d75effSDimitry Andric   return true;
49768d75effSDimitry Andric }
49868d75effSDimitry Andric 
4995ffd83dbSDimitry Andric void GetAllThreadAllocatorCachesLocked(InternalMmapVector<uptr> *caches) {}
5005ffd83dbSDimitry Andric 
50168d75effSDimitry Andric void ForEachExtraStackRange(tid_t os_id, RangeIteratorCallback callback,
50268d75effSDimitry Andric                             void *arg) {
50368d75effSDimitry Andric   __asan::AsanThread *t = __asan::GetAsanThreadByOsIDLocked(os_id);
504fe6060f1SDimitry Andric   if (!t)
505fe6060f1SDimitry Andric     return;
506fe6060f1SDimitry Andric   __asan::FakeStack *fake_stack = t->get_fake_stack();
507fe6060f1SDimitry Andric   if (!fake_stack)
508fe6060f1SDimitry Andric     return;
509fe6060f1SDimitry Andric   fake_stack->ForEachFakeFrame(callback, arg);
51068d75effSDimitry Andric }
51168d75effSDimitry Andric 
51268d75effSDimitry Andric void LockThreadRegistry() {
51368d75effSDimitry Andric   __asan::asanThreadRegistry().Lock();
51468d75effSDimitry Andric }
51568d75effSDimitry Andric 
51668d75effSDimitry Andric void UnlockThreadRegistry() {
51768d75effSDimitry Andric   __asan::asanThreadRegistry().Unlock();
51868d75effSDimitry Andric }
51968d75effSDimitry Andric 
52068d75effSDimitry Andric ThreadRegistry *GetThreadRegistryLocked() {
52168d75effSDimitry Andric   __asan::asanThreadRegistry().CheckLocked();
52268d75effSDimitry Andric   return &__asan::asanThreadRegistry();
52368d75effSDimitry Andric }
52468d75effSDimitry Andric 
52568d75effSDimitry Andric void EnsureMainThreadIDIsCorrect() {
52668d75effSDimitry Andric   __asan::EnsureMainThreadIDIsCorrect();
52768d75effSDimitry Andric }
52868d75effSDimitry Andric } // namespace __lsan
52968d75effSDimitry Andric 
53068d75effSDimitry Andric // ---------------------- Interface ---------------- {{{1
53168d75effSDimitry Andric using namespace __asan;
53268d75effSDimitry Andric 
53368d75effSDimitry Andric extern "C" {
53468d75effSDimitry Andric SANITIZER_INTERFACE_ATTRIBUTE
53568d75effSDimitry Andric void __sanitizer_start_switch_fiber(void **fakestacksave, const void *bottom,
53668d75effSDimitry Andric                                     uptr size) {
53768d75effSDimitry Andric   AsanThread *t = GetCurrentThread();
53868d75effSDimitry Andric   if (!t) {
53968d75effSDimitry Andric     VReport(1, "__asan_start_switch_fiber called from unknown thread\n");
54068d75effSDimitry Andric     return;
54168d75effSDimitry Andric   }
54268d75effSDimitry Andric   t->StartSwitchFiber((FakeStack**)fakestacksave, (uptr)bottom, size);
54368d75effSDimitry Andric }
54468d75effSDimitry Andric 
54568d75effSDimitry Andric SANITIZER_INTERFACE_ATTRIBUTE
54668d75effSDimitry Andric void __sanitizer_finish_switch_fiber(void* fakestack,
54768d75effSDimitry Andric                                      const void **bottom_old,
54868d75effSDimitry Andric                                      uptr *size_old) {
54968d75effSDimitry Andric   AsanThread *t = GetCurrentThread();
55068d75effSDimitry Andric   if (!t) {
55168d75effSDimitry Andric     VReport(1, "__asan_finish_switch_fiber called from unknown thread\n");
55268d75effSDimitry Andric     return;
55368d75effSDimitry Andric   }
55468d75effSDimitry Andric   t->FinishSwitchFiber((FakeStack*)fakestack,
55568d75effSDimitry Andric                        (uptr*)bottom_old,
55668d75effSDimitry Andric                        (uptr*)size_old);
55768d75effSDimitry Andric }
55868d75effSDimitry Andric }
559