diff --git a/libc/malloc_debug/Config.cpp b/libc/malloc_debug/Config.cpp
new file mode 100644
index 0000000..e27076d
--- /dev/null
+++ b/libc/malloc_debug/Config.cpp
@@ -0,0 +1,341 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/cdefs.h>
+
+#include <string>
+#include <vector>
+
+#include <sys/system_properties.h>
+
+#include <private/bionic_macros.h>
+
+#include "Config.h"
+#include "debug_log.h"
+
+struct Feature {
+  std::string name;
+  size_t default_value = 0;
+
+  uint64_t option = 0;
+  size_t* value = nullptr;
+  bool* config = nullptr;
+  // If set to true, then all of the options following are set on until
+  // for which the combo_option value is set.
+  bool combo_option = false;
+};
+
+class PropertyParser {
+ public:
+  PropertyParser(const char* property) : cur_(property) {}
+
+  bool Get(std::string* property, size_t* value, bool* value_set);
+
+  bool Done() { return done_; }
+
+  void LogUsage();
+
+  static constexpr uint8_t DEFAULT_FILL_ALLOC_VALUE = 0xeb;
+  static constexpr uint8_t DEFAULT_FILL_FREE_VALUE = 0xef;
+
+  static constexpr uint8_t DEFAULT_FRONT_GUARD_VALUE = 0xaa;
+  static constexpr uint8_t DEFAULT_REAR_GUARD_VALUE = 0xbb;
+
+ private:
+  const char* cur_ = nullptr;
+
+  bool done_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(PropertyParser);
+};
+
+bool PropertyParser::Get(std::string* property, size_t* value, bool* value_set) {
+  // Process each property name we can find.
+  while (isspace(*cur_))
+    ++cur_;
+
+  if (*cur_ == '\0') {
+    done_ = true;
+    return false;
+  }
+
+  const char* property_start = cur_;
+  while (!isspace(*cur_) && *cur_ != '=' && *cur_ != '\0')
+    ++cur_;
+
+  *property = std::string(property_start, cur_ - property_start);
+
+  // Skip any spaces after the name.
+  while (isspace(*cur_) && *cur_ != '=' && *cur_ != '\0')
+    ++cur_;
+
+  if (*cur_ == '=') {
+    ++cur_;
+    errno = 0;
+    *value_set = true;
+    char* end;
+    long read_value = strtol(cur_, const_cast<char**>(&end), 10);
+    if (errno != 0) {
+      error_log("%s: bad value for option '%s': %s", getprogname(), property->c_str(),
+                strerror(errno));
+      return false;
+    }
+    if (cur_ == end || (!isspace(*end) && *end != '\0')) {
+      if (cur_ == end) {
+        error_log("%s: bad value for option '%s'", getprogname(), property->c_str());
+      } else {
+        error_log("%s: bad value for option '%s', non space found after option: %s",
+                  getprogname(), property->c_str(), end);
+      }
+      return false;
+    } else if (read_value <= 0) {
+      error_log("%s: bad value for option '%s', value must be > 0: %ld",
+                getprogname(), property->c_str(), read_value);
+      return false;
+    }
+    *value = static_cast<size_t>(read_value);
+    cur_ = end;
+  } else {
+    *value_set = false;
+  }
+  return true;
+}
+
+void PropertyParser::LogUsage() {
+  error_log("malloc debug options usage:");
+  error_log("");
+  error_log("  front_guard[=XX]");
+  error_log("    Enables a front guard on all allocations. If XX is set");
+  error_log("    it sets the number of bytes in the guard. The default is");
+  error_log("    32 bytes.");
+  error_log("");
+  error_log("  rear_guard[=XX]");
+  error_log("    Enables a rear guard on all allocations. If XX is set");
+  error_log("    it sets the number of bytes in the guard. The default is");
+  error_log("    32 bytes.");
+  error_log("");
+  error_log("  guard[=XX]");
+  error_log("    Enables both a front guard and a rear guard on all allocations.");
+  error_log("    If XX is set it sets the number of bytes in both guards.");
+  error_log("    The default is 32 bytes.");
+  error_log("");
+  error_log("  backtrace[=XX]");
+  error_log("    Enable capturing the backtrace at the point of allocation.");
+  error_log("    If XX is set it sets the number of backtrace frames.");
+  error_log("    The default is 16 frames.");
+  error_log("");
+  error_log("  backtrace_enable_on_signal[=XX]");
+  error_log("    Enable capturing the backtrace at the point of allocation.");
+  error_log("    The backtrace capture is not enabled until the process");
+  error_log("    receives a signal. If XX is set it sets the number of backtrace");
+  error_log("    frames. The default is 16 frames.");
+  error_log("");
+  error_log("  fill_on_alloc[=XX]");
+  error_log("    On first allocation, fill with the value 0x%02x.", DEFAULT_FILL_ALLOC_VALUE);
+  error_log("    If XX is set it will only fill up to XX bytes of the");
+  error_log("    allocation. The default is to fill the entire allocation.");
+  error_log("");
+  error_log("  fill_on_free[=XX]");
+  error_log("    On free, fill with the value 0x%02x. If XX is set it will",
+            DEFAULT_FILL_FREE_VALUE);
+  error_log("    only fill up to XX bytes of the allocation. The default is to");
+  error_log("    fill the entire allocation.");
+  error_log("");
+  error_log("  fill[=XX]");
+  error_log("    On both first allocation free, fill with the value 0x%02x on",
+            DEFAULT_FILL_ALLOC_VALUE);
+  error_log("    first allocation and the value 0x%02x. If XX is set, only fill",
+            DEFAULT_FILL_FREE_VALUE);
+  error_log("    up to XX bytes. The default is to fill the entire allocation.");
+  error_log("");
+  error_log("  expand_alloc[=XX]");
+  error_log("    Allocate an extra number of bytes for every allocation call.");
+  error_log("    If XX is set, that is the number of bytes to expand the");
+  error_log("    allocation by. The default is 16 bytes.");
+  error_log("");
+  error_log("  free_track[=XX]");
+  error_log("    When a pointer is freed, do not free the memory right away.");
+  error_log("    Instead, keep XX of these allocations around and then verify");
+  error_log("    that they have not been modified when the total number of freed");
+  error_log("    allocations exceeds the XX amount. When the program terminates,");
+  error_log("    the rest of these allocations are verified.");
+  error_log("    The default is to record 100 allocations.");
+  error_log("");
+  error_log("  leak_track");
+  error_log("    Enable the leak tracking of memory allocations.");
+}
+
+static bool SetFeature(const Feature& feature, size_t value, bool value_set) {
+  if (feature.config) {
+    *feature.config = true;
+  }
+  if (feature.value != nullptr) {
+    if (value_set) {
+      *feature.value = value;
+    } else {
+      *feature.value = feature.default_value;
+    }
+  } else if (value_set) {
+     error_log("%s: value set for option '%s' which does not take a value",
+               getprogname(), feature.name.c_str());
+     return false;
+  }
+  return true;
+}
+
+// This function is designed to be called once. A second call will not
+// reset all variables.
+bool Config::SetFromProperties() {
+  char property_str[PROP_VALUE_MAX];
+  memset(property_str, 0, sizeof(property_str));
+  if (!__system_property_get("libc.debug.malloc.options", property_str)) {
+    return false;
+  }
+
+  // Initialize a few default values.
+  fill_alloc_value = PropertyParser::DEFAULT_FILL_ALLOC_VALUE;
+  fill_free_value = PropertyParser::DEFAULT_FILL_FREE_VALUE;
+  front_guard_value = PropertyParser::DEFAULT_FRONT_GUARD_VALUE;
+  rear_guard_value = PropertyParser::DEFAULT_REAR_GUARD_VALUE;
+  backtrace_signal = SIGRTMIN + 10;
+
+  // Parse the options are of the format:
+  //   option_name or option_name=XX
+
+  // Supported features:
+  const Feature features[] = {
+    { .name="guard", .default_value=32, .option=0, .combo_option=true },
+    // Enable front guard. Value is the size of the guard.
+    { .name="front_guard", .default_value=32, .option=FRONT_GUARD,
+      .value=&this->front_guard_bytes, .combo_option=true },
+    // Enable end guard. Value is the size of the guard.
+    { .name="rear_guard", .default_value=32, .option=REAR_GUARD,
+      .value=&this->rear_guard_bytes, .combo_option=true },
+
+    // Enable logging the backtrace on allocation. Value is the total
+    // number of frames to log.
+    { .name="backtrace", .default_value=16, .option=BACKTRACE | TRACK_ALLOCS,
+      .value=&this->backtrace_frames, .config=&this->backtrace_enabled },
+    // Enable gathering backtrace values on a signal.
+    { .name="backtrace_enable_on_signal", .default_value=16, .option=BACKTRACE | TRACK_ALLOCS,
+      .value=&this->backtrace_frames, .config=&this->backtrace_enable_on_signal },
+
+    { .name="fill", .default_value=SIZE_MAX, .option=0, .combo_option=true },
+    // Fill the allocation with an arbitrary pattern on allocation.
+    // Value is the number of bytes of the allocation to fill
+    // (default entire allocation).
+    { .name="fill_on_alloc", .default_value=SIZE_MAX, .option=FILL_ON_ALLOC,
+      .value=&this->fill_on_alloc_bytes, .combo_option=true },
+    // Fill the allocation with an arbitrary pattern on free.
+    // Value is the number of bytes of the allocation to fill
+    // (default entire allocation).
+    { .name="fill_on_free", .default_value=SIZE_MAX, .option=FILL_ON_FREE,
+      .value=&this->fill_on_free_bytes, .combo_option=true },
+
+    // Expand the size of every alloc by this number bytes. Value is
+    // the total number of bytes to expand every allocation by.
+    { .name="expand_alloc", .default_value=16, .option=EXPAND_ALLOC,
+      .value=&this->expand_alloc_bytes, },
+
+    // Keep track of the freed allocations and verify at a later date
+    // that they have not been used. Turning this on, also turns on
+    // fill on free.
+    { .name="free_track", .default_value=100, .option=FREE_TRACK | FILL_ON_FREE,
+      .value=&this->free_track_allocations, },
+
+    // Enable printing leaked allocations.
+    { .name="leak_track", .option=LEAK_TRACK | TRACK_ALLOCS },
+  };
+
+  // Process each property name we can find.
+  std::string property;
+  size_t value;
+  bool value_set;
+  PropertyParser parser(property_str);
+  bool found = false;
+  bool valid = true;
+  while (valid && parser.Get(&property, &value, &value_set)) {
+    for (size_t i = 0; i < sizeof(features)/sizeof(Feature); i++) {
+      if (property == features[i].name) {
+        if (features[i].option == 0 && features[i].combo_option) {
+          i++;
+          for (; i < sizeof(features)/sizeof(Feature) && features[i].combo_option; i++) {
+            if (!SetFeature(features[i], value, value_set)) {
+              valid = false;
+              break;
+            }
+            options |= features[i].option;
+          }
+          if (!valid) {
+            break;
+          }
+        } else {
+          if (!SetFeature(features[i], value, value_set)) {
+            valid = false;
+            break;
+          }
+          options |= features[i].option;
+        }
+        found = true;
+        break;
+      }
+    }
+    if (valid && !found) {
+      error_log("%s: unknown option %s", getprogname(), property.c_str());
+      valid = false;
+      break;
+    }
+  }
+
+  valid = valid && parser.Done();
+
+  if (valid) {
+    // It's necessary to align the front guard to sizeof(uintptr_t) to
+    // make sure that the header is aligned properly.
+    if (options & FRONT_GUARD) {
+      front_guard_bytes = BIONIC_ALIGN(front_guard_bytes, sizeof(uintptr_t));
+    }
+
+    // This situation can occur if the free_track option is specified and
+    // the fill_on_free option is not. In this case, indicate the whole
+    // allocation should be filled.
+    if ((options & FILL_ON_FREE) && fill_on_free_bytes == 0) {
+      fill_on_free_bytes = SIZE_MAX;
+    }
+  } else {
+    parser.LogUsage();
+  }
+
+  return valid;
+}