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diff --git a/lib/libtsan/sanitizer_common/sanitizer_libignore.h b/lib/libtsan/sanitizer_common/sanitizer_libignore.h
new file mode 100644
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+++ b/lib/libtsan/sanitizer_common/sanitizer_libignore.h
@@ -0,0 +1,126 @@
+//===-- sanitizer_libignore.h -----------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// LibIgnore allows to ignore all interceptors called from a particular set
+// of dynamic libraries. LibIgnore can be initialized with several templates
+// of names of libraries to be ignored. It finds code ranges for the libraries;
+// and checks whether the provided PC value belongs to the code ranges.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_LIBIGNORE_H
+#define SANITIZER_LIBIGNORE_H
+
+#include "sanitizer_internal_defs.h"
+#include "sanitizer_common.h"
+#include "sanitizer_atomic.h"
+#include "sanitizer_mutex.h"
+
+namespace __sanitizer {
+
+class LibIgnore {
+ public:
+  explicit LibIgnore(LinkerInitialized);
+
+  // Must be called during initialization.
+  void AddIgnoredLibrary(const char *name_templ);
+  void IgnoreNoninstrumentedModules(bool enable) {
+    track_instrumented_libs_ = enable;
+  }
+
+  // Must be called after a new dynamic library is loaded.
+  void OnLibraryLoaded(const char *name);
+
+  // Must be called after a dynamic library is unloaded.
+  void OnLibraryUnloaded();
+
+  // Checks whether the provided PC belongs to one of the ignored libraries or
+  // the PC should be ignored because it belongs to an non-instrumented module
+  // (when ignore_noninstrumented_modules=1). Also returns true via
+  // "pc_in_ignored_lib" if the PC is in an ignored library, false otherwise.
+  bool IsIgnored(uptr pc, bool *pc_in_ignored_lib) const;
+
+  // Checks whether the provided PC belongs to an instrumented module.
+  bool IsPcInstrumented(uptr pc) const;
+
+ private:
+  static const uptr kMaxIgnoredRanges = 128;
+  static const uptr kMaxInstrumentedRanges = 1024;
+  static const uptr kMaxLibs = 1024;
+  static const uptr kInvalidCodeRangeId = -1;
+
+  struct Lib {
+    char *templ;
+    char *name;
+    char *real_name;  // target of symlink
+    uptr range_id;
+    bool loaded() const { return range_id != kInvalidCodeRangeId; };
+  };
+
+  struct LibCodeRange {
+    bool IsInRange(uptr pc) const {
+      return (pc >= begin && pc < atomic_load(&end, memory_order_acquire));
+    }
+
+    void OnLoad(uptr b, uptr e) {
+      begin = b;
+      atomic_store(&end, e, memory_order_release);
+    }
+
+    void OnUnload() { atomic_store(&end, 0, memory_order_release); }
+
+   private:
+    uptr begin;
+    // A value of 0 means the associated module was unloaded.
+    atomic_uintptr_t end;
+  };
+
+  // Hot part:
+  atomic_uintptr_t ignored_ranges_count_;
+  LibCodeRange ignored_code_ranges_[kMaxIgnoredRanges];
+
+  atomic_uintptr_t instrumented_ranges_count_;
+  LibCodeRange instrumented_code_ranges_[kMaxInstrumentedRanges];
+
+  // Cold part:
+  Mutex mutex_;
+  uptr count_;
+  Lib libs_[kMaxLibs];
+  bool track_instrumented_libs_;
+
+  // Disallow copying of LibIgnore objects.
+  LibIgnore(const LibIgnore&);  // not implemented
+  void operator = (const LibIgnore&);  // not implemented
+};
+
+inline bool LibIgnore::IsIgnored(uptr pc, bool *pc_in_ignored_lib) const {
+  const uptr n = atomic_load(&ignored_ranges_count_, memory_order_acquire);
+  for (uptr i = 0; i < n; i++) {
+    if (ignored_code_ranges_[i].IsInRange(pc)) {
+      *pc_in_ignored_lib = true;
+      return true;
+    }
+  }
+  *pc_in_ignored_lib = false;
+  if (track_instrumented_libs_ && !IsPcInstrumented(pc))
+    return true;
+  return false;
+}
+
+inline bool LibIgnore::IsPcInstrumented(uptr pc) const {
+  const uptr n = atomic_load(&instrumented_ranges_count_, memory_order_acquire);
+  for (uptr i = 0; i < n; i++) {
+    if (instrumented_code_ranges_[i].IsInRange(pc))
+      return true;
+  }
+  return false;
+}
+
+}  // namespace __sanitizer
+
+#endif  // SANITIZER_LIBIGNORE_H