Revert "Add API to temporalily disable usage of ASAN's fake stack"

This reverts commit 4e72801.

Author: vitalybuka

compiler-rt/include/sanitizer/asan_interface.h

@@ -333,13 +333,6 @@ void SANITIZER_CDECL __asan_handle_no_return(void);
 /// trace. Returns 1 if successful, 0 if not.
 int SANITIZER_CDECL __asan_update_allocation_context(void *addr);
 
-/// Disables fake stack for the current thread.
-/// Temporarily disables use-after-return detection for current thread.
-void SANITIZER_CDECL __asan_disable_fake_stack(void);
-
-/// (Re)enables fake stack for the current thread.
-void SANITIZER_CDECL __asan_enable_fake_stack(void);
-
 #ifdef __cplusplus
 } // extern "C"
 #endif

compiler-rt/lib/asan/asan_fake_stack.cpp

@@ -217,44 +217,26 @@ static THREADLOCAL FakeStack *fake_stack_tls;
 FakeStack *GetTLSFakeStack() {
   return fake_stack_tls;
 }
-void SetTLSFakeStack(AsanThread* t, FakeStack* fs) {
-  if (fs && !t->IsFakeStackEnabled()) {
-    return;
-  }
+void SetTLSFakeStack(FakeStack *fs) {
   fake_stack_tls = fs;
 }
 #else
 FakeStack *GetTLSFakeStack() { return 0; }
-void SetTLSFakeStack(AsanThread* t, FakeStack* fs) {}
+void SetTLSFakeStack(FakeStack *fs) { }
 #endif  // (SANITIZER_LINUX && !SANITIZER_ANDROID) || SANITIZER_FUCHSIA
 
-static void DisableFakeStack() {
+static FakeStack *GetFakeStack() {
   AsanThread *t = GetCurrentThread();
-  if (t) {
-    t->SetFakeStackEnabled(false);
-  }
-}
-
-static void EnableFakeStack() {
-  AsanThread* t = GetCurrentThread();
-  if (t) {
-    t->SetFakeStackEnabled(true);
-  }
-}
-
-static FakeStack* GetFakeStack(bool for_allocation = true) {
-  AsanThread* t = GetCurrentThread();
-  if (!t || (for_allocation && !t->IsFakeStackEnabled()))
-    return nullptr;
+  if (!t) return nullptr;
   return t->get_or_create_fake_stack();
 }
 
-static FakeStack* GetFakeStackFast(bool for_allocation = true) {
+static FakeStack *GetFakeStackFast() {
   if (FakeStack *fs = GetTLSFakeStack())
     return fs;
   if (!__asan_option_detect_stack_use_after_return)
     return nullptr;
-  return GetFakeStack(for_allocation);
+  return GetFakeStack();
 }
 
 static FakeStack *GetFakeStackFastAlways() {
@@ -329,9 +311,7 @@ extern "C" {
 // -asan-use-after-return=never, after modal UAR flag lands
 // (https://github.com/google/sanitizers/issues/1394)
 SANITIZER_INTERFACE_ATTRIBUTE
-void* __asan_get_current_fake_stack() {
-  return GetFakeStackFast(/*for_allocation=*/false);
-}
+void *__asan_get_current_fake_stack() { return GetFakeStackFast(); }
 
 SANITIZER_INTERFACE_ATTRIBUTE
 void *__asan_addr_is_in_fake_stack(void *fake_stack, void *addr, void **beg,
@@ -369,9 +349,4 @@ void __asan_allocas_unpoison(uptr top, uptr bottom) {
   (reinterpret_cast<void *>(MemToShadow(top)), 0,
    (bottom - top) / ASAN_SHADOW_GRANULARITY);
 }
-
-SANITIZER_INTERFACE_ATTRIBUTE
-void __asan_disable_fake_stack() { return DisableFakeStack(); }
-SANITIZER_INTERFACE_ATTRIBUTE
-void __asan_enable_fake_stack() { return EnableFakeStack(); }
 } // extern "C"

compiler-rt/lib/asan/asan_fake_stack.h

@@ -18,8 +18,6 @@
 
 namespace __asan {
 
-class AsanThread;
-
 // Fake stack frame contains local variables of one function.
 struct FakeFrame {
   uptr magic;  // Modified by the instrumented code.
@@ -198,7 +196,7 @@ class FakeStack {
 };
 
 FakeStack *GetTLSFakeStack();
-void SetTLSFakeStack(AsanThread* t, FakeStack* fs);
+void SetTLSFakeStack(FakeStack *fs);
 
 }  // namespace __asan
 

compiler-rt/lib/asan/asan_interface.inc

@@ -15,8 +15,6 @@ INTERFACE_FUNCTION(__asan_alloca_poison)
 INTERFACE_FUNCTION(__asan_allocas_unpoison)
 INTERFACE_FUNCTION(__asan_before_dynamic_init)
 INTERFACE_FUNCTION(__asan_describe_address)
-INTERFACE_FUNCTION(__asan_disable_fake_stack)
-INTERFACE_FUNCTION(__asan_enable_fake_stack)
 INTERFACE_FUNCTION(__asan_exp_load1)
 INTERFACE_FUNCTION(__asan_exp_load2)
 INTERFACE_FUNCTION(__asan_exp_load4)

compiler-rt/lib/asan/asan_thread.cpp

@@ -163,7 +163,7 @@ void AsanThread::StartSwitchFiber(FakeStack **fake_stack_save, uptr bottom,
   if (fake_stack_save)
     *fake_stack_save = fake_stack_;
   fake_stack_ = nullptr;
-  SetTLSFakeStack(this, nullptr);
+  SetTLSFakeStack(nullptr);
   // if fake_stack_save is null, the fiber will die, delete the fakestack
   if (!fake_stack_save && current_fake_stack)
     current_fake_stack->Destroy(this->tid());
@@ -177,7 +177,7 @@ void AsanThread::FinishSwitchFiber(FakeStack *fake_stack_save, uptr *bottom_old,
   }
 
   if (fake_stack_save) {
-    SetTLSFakeStack(this, fake_stack_save);
+    SetTLSFakeStack(fake_stack_save);
     fake_stack_ = fake_stack_save;
   }
 
@@ -242,7 +242,7 @@ FakeStack *AsanThread::AsyncSignalSafeLazyInitFakeStack() {
         Max(stack_size_log, static_cast<uptr>(flags()->min_uar_stack_size_log));
     fake_stack_ = FakeStack::Create(stack_size_log);
     DCHECK_EQ(GetCurrentThread(), this);
-    SetTLSFakeStack(this, fake_stack_);
+    SetTLSFakeStack(fake_stack_);
     return fake_stack_;
   }
   return nullptr;
@@ -251,7 +251,6 @@ FakeStack *AsanThread::AsyncSignalSafeLazyInitFakeStack() {
 void AsanThread::Init(const InitOptions *options) {
   DCHECK_NE(tid(), kInvalidTid);
   next_stack_top_ = next_stack_bottom_ = 0;
-  fake_stack_enabled_ = true;
   atomic_store(&stack_switching_, false, memory_order_release);
   CHECK_EQ(this->stack_size(), 0U);
   SetThreadStackAndTls(options);

compiler-rt/lib/asan/asan_thread.h

@@ -104,7 +104,7 @@ class AsanThread {
     if (!fake_stack_) return;
     FakeStack *t = fake_stack_;
     fake_stack_ = nullptr;
-    SetTLSFakeStack(this, nullptr);
+    SetTLSFakeStack(nullptr);
     t->Destroy(tid);
   }
 
@@ -144,14 +144,6 @@ class AsanThread {
     GetStartData(&data, sizeof(data));
   }
 
-  bool IsFakeStackEnabled() const { return fake_stack_enabled_; }
-  void SetFakeStackEnabled(bool enabled) {
-    fake_stack_enabled_ = enabled;
-    if (!enabled) {
-      SetTLSFakeStack(this, nullptr);
-    }
-  }
-
  private:
   // NOTE: There is no AsanThread constructor. It is allocated
   // via mmap() and *must* be valid in zero-initialized state.
@@ -187,7 +179,6 @@ class AsanThread {
   DTLS *dtls_;
 
   FakeStack *fake_stack_;
-  bool fake_stack_enabled_;
   AsanThreadLocalMallocStorage malloc_storage_;
   AsanStats stats_;
   bool unwinding_;

compiler-rt/lib/asan_abi/asan_abi.cpp

@@ -73,8 +73,6 @@ void *__asan_abi_addr_is_in_fake_stack(void *fake_stack, void *addr, void **beg,
                                        void **end) {
   return NULL;
 }
-void __asan_abi_disable_fake_stack(void) {}
-void __asan_abi_enable_fake_stack(void) {}
 
 // Functions concerning poisoning and unpoisoning fake stack alloca
 void __asan_abi_alloca_poison(void *addr, size_t size) {}

compiler-rt/lib/asan_abi/asan_abi.h

@@ -76,9 +76,6 @@ void *__asan_abi_load_cxx_array_cookie(void **p);
 void *__asan_abi_get_current_fake_stack();
 void *__asan_abi_addr_is_in_fake_stack(void *fake_stack, void *addr, void **beg,
                                        void **end);
-void *__asan_abi_disable_fake_stack();
-void *__asan_abi_enable_fake_stack();
-
 // Functions concerning poisoning and unpoisoning fake stack alloca
 void __asan_abi_alloca_poison(void *addr, size_t size);
 void __asan_abi_allocas_unpoison(void *top, void *bottom);

compiler-rt/lib/asan_abi/asan_abi_shim.cpp

@@ -365,8 +365,6 @@ void *__asan_addr_is_in_fake_stack(void *fake_stack, void *addr, void **beg,
                                    void **end) {
   return __asan_abi_addr_is_in_fake_stack(fake_stack, addr, beg, end);
 }
-void __asan_disable_fake_stack(void) { return __asan_abi_disable_fake_stack(); }
-void __asan_enable_fake_stack(void) { return __asan_abi_enable_fake_stack(); }
 
 // Functions concerning poisoning and unpoisoning fake stack alloca
 void __asan_alloca_poison(uptr addr, uptr size) {