This patch adds a new third-party library that implements an ELF dynamic linker.

third_party/crazy_linker/crazy_linker/src/crazy_linker_thread.cpp

Index: third_party/crazy_linker/crazy_linker/src/crazy_linker_thread.cpp
diff --git a/third_party/crazy_linker/crazy_linker/src/crazy_linker_thread.cpp b/third_party/crazy_linker/crazy_linker/src/crazy_linker_thread.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e49b9dff274363c140cbd56e06090af2bd5e35e5
--- /dev/null
+++ b/third_party/crazy_linker/crazy_linker/src/crazy_linker_thread.cpp
@@ -0,0 +1,84 @@
+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "crazy_linker_thread.h"
+
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+namespace {
+
+static pthread_key_t s_thread_key;
+static pthread_once_t s_once = PTHREAD_ONCE_INIT;
+
+static void ThreadDataDestroy(void* data) {
+  free(data);
+}
+
+static void InitThreadKey() {
+  pthread_key_create(&s_thread_key, ThreadDataDestroy);
+}
+
+}  // namespace
+
+namespace crazy {
+
+void ThreadData::Init() {
+  dlerror_ = dlerror_buffers_[0];
+  dlerror_[0] = '\0';
+}
+
+void ThreadData::SwapErrorBuffers() {
+  if (dlerror_ == dlerror_buffers_[0])
+    dlerror_ = dlerror_buffers_[1];
+  else
+    dlerror_ = dlerror_buffers_[0];
+  dlerror_[0] = '\0';
+}
+
+void ThreadData::SetErrorArgs(const char* fmt, va_list args) {
+  if (fmt == NULL) {
+    dlerror_[0] = '\0';
+    return;
+  }
+  vsnprintf(dlerror_, kBufferSize, fmt, args);
+}
+
+void ThreadData::AppendErrorArgs(const char* fmt, va_list args) {
+  if (fmt == NULL)
+    return;
+  size_t len = strlen(dlerror_);
+  vsnprintf(dlerror_ + len, kBufferSize - len, fmt, args);
+}
+
+ThreadData* GetThreadDataFast() {
+  return reinterpret_cast<ThreadData*>(pthread_getspecific(s_thread_key));
+}
+
+ThreadData* GetThreadData() {
+  pthread_once(&s_once, InitThreadKey);
+  ThreadData* data = GetThreadDataFast();
+  if (!data) {
+    data = reinterpret_cast<ThreadData*>(calloc(sizeof(*data), 1));
+    data->Init();
+    pthread_setspecific(s_thread_key, data);
+  }
+  return data;
+}
+
+// Set the linker error string for the current thread.
+void SetLinkerErrorString(const char* str) {
+  GetThreadData()->SetError(str);
+}
+
+// Set the formatted linker error for the current thread.
+void SetLinkerError(const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  GetThreadData()->SetErrorArgs(fmt, args);
+  va_end(args);
+}
+
+}  // namespace crazy