diff --git a/android-changes-for-ndk-developers.md b/android-changes-for-ndk-developers.md
index 4c13bec..1fdb1e4 100644
--- a/android-changes-for-ndk-developers.md
+++ b/android-changes-for-ndk-developers.md
@@ -330,6 +330,16 @@
 configured your build system to generate incorrect SONAME entries (using
 the -soname linker option).
 
+## `__register_atfork` (Available in API level >= 23)
+
+To allow `atfork` and `pthread_atfork` handlers to be unregistered on
+`dlclose`, the implementation changed in API level 23. Unfortunately this
+requires a new libc function `__register_atfork`. Code using these functions
+that is built with a target API level >= 23 therefore will not load on earlier
+versions of Android, with an error referencing `__register_atfork`.
+
+*Resolution*: build your code with an NDK target API level that matches your
+app's minimum API level, or avoid using `atfork`/`pthread_atfork`.
 
 ## DT_RUNPATH support (Available in API level >= 24)
 
diff --git a/benchmarks/Android.bp b/benchmarks/Android.bp
index 06c0ba3..370e040 100644
--- a/benchmarks/Android.bp
+++ b/benchmarks/Android.bp
@@ -61,8 +61,8 @@
 }
 
 // Build benchmarks for the device (with bionic's .so). Run with:
-//   adb shell bionic-benchmarks32
-//   adb shell bionic-benchmarks64
+//   adb shell /data/benchmarktest/bionic-benchmarks/bionic-benchmarks
+//   adb shell /data/benchmarktest64/bionic-benchmarks/bionic-benchmarks
 cc_benchmark {
     name: "bionic-benchmarks",
     defaults: ["bionic-benchmarks-defaults"],
diff --git a/libc/Android.bp b/libc/Android.bp
index e91038f..174783f 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -762,12 +762,13 @@
                 "arch-arm/generic/bionic/strlen.c",
 
                 "arch-arm/bionic/__aeabi_read_tp.S",
-                "arch-arm/bionic/atomics_arm.c",
                 "arch-arm/bionic/__bionic_clone.S",
+                "arch-arm/bionic/__restore.S",
                 "arch-arm/bionic/_exit_with_stack_teardown.S",
+                "arch-arm/bionic/atomics_arm.c",
+                "arch-arm/bionic/bpabi.c",
                 "arch-arm/bionic/libcrt_compat.c",
                 "arch-arm/bionic/popcount_tab.c",
-                "arch-arm/bionic/__restore.S",
                 "arch-arm/bionic/setjmp.S",
                 "arch-arm/bionic/syscall.S",
                 "arch-arm/bionic/vfork.S",
@@ -1462,12 +1463,7 @@
             srcs: ["arch-x86/dynamic_function_dispatch.cpp"],
         },
         arm: {
-            srcs: [
-                "arch-arm/dynamic_function_dispatch.cpp",
-
-                // Workaround for b/120254692.
-                "arch-arm/dynamic_function_wrapper.S",
-            ],
+            srcs: ["arch-arm/dynamic_function_dispatch.cpp"],
         },
     },
 
diff --git a/libc/NOTICE b/libc/NOTICE
index 120c4fd..298901f 100644
--- a/libc/NOTICE
+++ b/libc/NOTICE
@@ -418,50 +418,6 @@
 
 -------------------------------------------------------------------
 
-Copyright (C) 2007 The Android Open Source Project
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-     http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-
--------------------------------------------------------------------
-
-Copyright (C) 2007 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.
-
--------------------------------------------------------------------
-
 Copyright (C) 2008 The Android Open Source Project
 
 Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/libc/arch-arm/dynamic_function_wrapper.S b/libc/arch-arm/bionic/bpabi.c
similarity index 68%
rename from libc/arch-arm/dynamic_function_wrapper.S
rename to libc/arch-arm/bionic/bpabi.c
index 1d2842b..5c9cd99 100644
--- a/libc/arch-arm/dynamic_function_wrapper.S
+++ b/libc/arch-arm/bionic/bpabi.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2018 The Android Open Source Project
+ * Copyright (C) 2019 The Android Open Source Project
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -26,12 +26,18 @@
  * SUCH DAMAGE.
  */
 
-#include <private/bionic_asm.h>
+extern long long __divdi3(long long, long long);
+extern unsigned long long __udivdi3(unsigned long long, unsigned long long);
 
-#define FUNCTION_DELEGATE(name, impl) \
-ENTRY(name); \
-    b impl; \
-END(name)
+long long __gnu_ldivmod_helper(long long a, long long b, long long* remainder) {
+  long long quotient = __divdi3(a, b);
+  *remainder = a - b * quotient;
+  return quotient;
+}
 
-FUNCTION_DELEGATE(strcmp, strcmp_internal)
-FUNCTION_DELEGATE(strlen, strlen_internal)
+unsigned long long __gnu_uldivmod_helper(unsigned long long a, unsigned long long b,
+                                         unsigned long long* remainder) {
+  unsigned long long quotient = __udivdi3(a, b);
+  *remainder = a - b * quotient;
+  return quotient;
+}
diff --git a/libc/arch-arm/dynamic_function_dispatch.cpp b/libc/arch-arm/dynamic_function_dispatch.cpp
index 09fd8f3..640f330 100644
--- a/libc/arch-arm/dynamic_function_dispatch.cpp
+++ b/libc/arch-arm/dynamic_function_dispatch.cpp
@@ -89,15 +89,11 @@
     return r0;
 }
 
-#define DEFINE_IFUNC_WITH_SUFFIX(name, suffix) \
-    name##_func name##suffix __attribute__((ifunc(#name "_resolver"))); \
+#define DEFINE_IFUNC(name) \
+    name##_func name __attribute__((ifunc(#name "_resolver"))); \
     __attribute__((visibility("hidden"))) \
     name##_func* name##_resolver()
 
-#define DEFINE_IFUNC(name) DEFINE_IFUNC_WITH_SUFFIX(name, )
-
-#define DEFINE_INTERNAL_IFUNC(name) DEFINE_IFUNC_WITH_SUFFIX(name, _internal)
-
 #define DECLARE_FUNC(type, name) \
     __attribute__((visibility("hidden"))) \
     type name
@@ -291,7 +287,7 @@
 }
 
 typedef int strcmp_func(const char* __lhs, const char* __rhs);
-DEFINE_INTERNAL_IFUNC(strcmp) {
+DEFINE_IFUNC(strcmp) {
     switch(get_cpu_variant()) {
         case kCortexA9:
             RETURN_FUNC(strcmp_func, strcmp_a9);
@@ -305,7 +301,7 @@
 }
 
 typedef size_t strlen_func(const char* __s);
-DEFINE_INTERNAL_IFUNC(strlen) {
+DEFINE_IFUNC(strlen) {
     switch(get_cpu_variant()) {
         case kCortexA9:
             RETURN_FUNC(strlen_func, strlen_a9);
diff --git a/libc/bionic/malloc_common.cpp b/libc/bionic/malloc_common.cpp
index 3f1bcc3..9dc4d12 100644
--- a/libc/bionic/malloc_common.cpp
+++ b/libc/bionic/malloc_common.cpp
@@ -32,14 +32,7 @@
 // calls and add special debugging code to attempt to catch allocation
 // errors. All of the debugging code is implemented in a separate shared
 // library that is only loaded when the property "libc.debug.malloc.options"
-// is set to a non-zero value. There are two functions exported to
-// allow ddms, or other external users to get information from the debug
-// allocation.
-//   get_malloc_leak_info: Returns information about all of the known native
-//                         allocations that are currently in use.
-//   free_malloc_leak_info: Frees the data allocated by the call to
-//                          get_malloc_leak_info.
-//   write_malloc_leak_info: Writes the leak info data to a file.
+// is set to a non-zero value.
 
 #include <errno.h>
 #include <stdint.h>
@@ -162,7 +155,7 @@
   return result;
 }
 
-extern "C" void* realloc(void* old_mem, size_t bytes) {
+extern "C" __attribute__((__noinline__)) void* realloc(void* old_mem, size_t bytes) {
   auto dispatch_table = GetDispatchTable();
   if (__predict_false(dispatch_table != nullptr)) {
     return dispatch_table->realloc(old_mem, bytes);
diff --git a/libc/bionic/malloc_common_dynamic.cpp b/libc/bionic/malloc_common_dynamic.cpp
index 64f9f6f..599ac6a 100644
--- a/libc/bionic/malloc_common_dynamic.cpp
+++ b/libc/bionic/malloc_common_dynamic.cpp
@@ -409,39 +409,29 @@
 // =============================================================================
 // Functions to support dumping of native heap allocations using malloc debug.
 // =============================================================================
-
-// Retrieve native heap information.
-//
-// "*info" is set to a buffer we allocate
-// "*overall_size" is set to the size of the "info" buffer
-// "*info_size" is set to the size of a single entry
-// "*total_memory" is set to the sum of all allocations we're tracking; does
-//   not include heap overhead
-// "*backtrace_size" is set to the maximum number of entries in the back trace
-extern "C" void get_malloc_leak_info(uint8_t** info, size_t* overall_size,
-    size_t* info_size, size_t* total_memory, size_t* backtrace_size) {
+bool GetMallocLeakInfo(android_mallopt_leak_info_t* leak_info) {
   void* func = gFunctions[FUNC_GET_MALLOC_LEAK_INFO];
   if (func == nullptr) {
-    return;
+    errno = ENOTSUP;
+    return false;
   }
-  reinterpret_cast<get_malloc_leak_info_func_t>(func)(info, overall_size, info_size, total_memory,
-                                                      backtrace_size);
+  reinterpret_cast<get_malloc_leak_info_func_t>(func)(
+      &leak_info->buffer, &leak_info->overall_size, &leak_info->info_size,
+      &leak_info->total_memory, &leak_info->backtrace_size);
+  return true;
 }
 
-extern "C" void free_malloc_leak_info(uint8_t* info) {
+bool FreeMallocLeakInfo(android_mallopt_leak_info_t* leak_info) {
   void* func = gFunctions[FUNC_FREE_MALLOC_LEAK_INFO];
   if (func == nullptr) {
-    return;
+    errno = ENOTSUP;
+    return false;
   }
-  reinterpret_cast<free_malloc_leak_info_func_t>(func)(info);
+  reinterpret_cast<free_malloc_leak_info_func_t>(func)(leak_info->buffer);
+  return true;
 }
 
-extern "C" void write_malloc_leak_info(FILE* fp) {
-  if (fp == nullptr) {
-    error_log("write_malloc_leak_info called with a nullptr");
-    return;
-  }
-
+bool WriteMallocLeakInfo(FILE* fp) {
   void* func = gFunctions[FUNC_WRITE_LEAK_INFO];
   bool written = false;
   if (func != nullptr) {
@@ -453,7 +443,9 @@
     fprintf(fp, "# adb shell stop\n");
     fprintf(fp, "# adb shell setprop libc.debug.malloc.options backtrace\n");
     fprintf(fp, "# adb shell start\n");
+    errno = ENOTSUP;
   }
+  return written;
 }
 // =============================================================================
 
@@ -484,6 +476,27 @@
   if (opcode == M_SET_ALLOCATION_LIMIT_BYTES) {
     return LimitEnable(arg, arg_size);
   }
+  if (opcode == M_WRITE_MALLOC_LEAK_INFO_TO_FILE) {
+    if (arg == nullptr || arg_size != sizeof(FILE*)) {
+      errno = EINVAL;
+      return false;
+    }
+    return WriteMallocLeakInfo(reinterpret_cast<FILE*>(arg));
+  }
+  if (opcode == M_GET_MALLOC_LEAK_INFO) {
+    if (arg == nullptr || arg_size != sizeof(android_mallopt_leak_info_t)) {
+      errno = EINVAL;
+      return false;
+    }
+    return GetMallocLeakInfo(reinterpret_cast<android_mallopt_leak_info_t*>(arg));
+  }
+  if (opcode == M_FREE_MALLOC_LEAK_INFO) {
+    if (arg == nullptr || arg_size != sizeof(android_mallopt_leak_info_t)) {
+      errno = EINVAL;
+      return false;
+    }
+    return FreeMallocLeakInfo(reinterpret_cast<android_mallopt_leak_info_t*>(arg));
+  }
   return HeapprofdMallopt(opcode, arg, arg_size);
 }
 // =============================================================================
diff --git a/libc/bionic/pthread_mutex.cpp b/libc/bionic/pthread_mutex.cpp
index d9ddf10..37031ad 100644
--- a/libc/bionic/pthread_mutex.cpp
+++ b/libc/bionic/pthread_mutex.cpp
@@ -199,6 +199,8 @@
                                                                    memory_order_relaxed))) {
             return 0;
         }
+    } else {
+        old_owner = atomic_load_explicit(&mutex.owner_tid, memory_order_relaxed);
     }
 
     if (tid != (old_owner & FUTEX_TID_MASK)) {
@@ -644,6 +646,15 @@
         // we call wake, the thread we eventually wake will find an unlocked mutex
         // and will execute. Either way we have correct behavior and nobody is
         // orphaned on the wait queue.
+        //
+        // The pthread_mutex_internal_t object may have been deallocated between the
+        // atomic exchange and the wake call. In that case, this wake call could
+        // target unmapped memory or memory used by an otherwise unrelated futex
+        // operation. Even if the kernel avoids spurious futex wakeups from its
+        // point of view, this wake call could trigger a spurious wakeup in any
+        // futex accessible from this process. References:
+        //  - https://lkml.org/lkml/2014/11/27/472
+        //  - http://austingroupbugs.net/view.php?id=811#c2267
         __futex_wake_ex(&mutex->state, shared, 1);
     }
 }
diff --git a/libc/include/paths.h b/libc/include/paths.h
index 0cf2789..58540d9 100644
--- a/libc/include/paths.h
+++ b/libc/include/paths.h
@@ -47,7 +47,7 @@
 #define _PATH_CONSOLE "/dev/console"
 
 /** Default shell search path. */
-#define _PATH_DEFPATH "/sbin:/system/sbin:/product/bin:/apex/com.android.runtime/bin:/system/bin:/system/xbin:/odm/bin:/vendor/bin:/vendor/xbin"
+#define _PATH_DEFPATH "/product/bin:/apex/com.android.runtime/bin:/system/bin:/system/xbin:/odm/bin:/vendor/bin:/vendor/xbin"
 
 /** Path to the directory containing device files. */
 #define _PATH_DEV "/dev/"
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index 5e49d3a..4a734fc 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1473,15 +1473,10 @@
     malloc_enable; # apex
     malloc_iterate; # apex
 
-    # Used by libmediautils
-    write_malloc_leak_info; # apex
-    free_malloc_leak_info; # apex
-    get_malloc_leak_info; # apex
-
     # Used by libandroid_net
     android_getaddrinfofornet; # apex
 
-    # Used by libandroid_runtime and libmedia
+    # Used by libandroid_runtime, libmedia and libmediautils
     android_mallopt; # apex
 } LIBC_P;
 
diff --git a/libc/malloc_hooks/tests/malloc_hooks_tests.cpp b/libc/malloc_hooks/tests/malloc_hooks_tests.cpp
index 0d23a6a..86e20ea 100644
--- a/libc/malloc_hooks/tests/malloc_hooks_tests.cpp
+++ b/libc/malloc_hooks/tests/malloc_hooks_tests.cpp
@@ -38,6 +38,7 @@
 
 #include <gtest/gtest.h>
 
+#include <private/bionic_malloc.h>
 #include <private/bionic_malloc_dispatch.h>
 #include <tests/utils.h>
 
@@ -197,19 +198,15 @@
 }
 
 TEST_F(MallocHooksTest, DISABLED_extended_functions) {
-  uint8_t* info = nullptr;
-  size_t overall_size = 100;
-  size_t info_size = 200;
-  size_t total_memory = 300;
-  size_t backtrace_size = 400;
-  get_malloc_leak_info(&info, &overall_size, &info_size, &total_memory, &backtrace_size);
-  EXPECT_EQ(nullptr, info);
-  EXPECT_EQ(0U, overall_size);
-  EXPECT_EQ(0U, info_size);
-  EXPECT_EQ(0U, total_memory);
-  EXPECT_EQ(0U, backtrace_size);
+  android_mallopt_leak_info_t leak_info;
+  ASSERT_TRUE(android_mallopt(M_GET_MALLOC_LEAK_INFO, &leak_info, sizeof(leak_info)));
+  EXPECT_EQ(nullptr, leak_info.buffer);
+  EXPECT_EQ(0U, leak_info.overall_size);
+  EXPECT_EQ(0U, leak_info.info_size);
+  EXPECT_EQ(0U, leak_info.total_memory);
+  EXPECT_EQ(0U, leak_info.backtrace_size);
 
-  free_malloc_leak_info(info);
+  ASSERT_TRUE(android_mallopt(M_FREE_MALLOC_LEAK_INFO, &leak_info, sizeof(leak_info)));
 
   malloc_enable();
   malloc_disable();
diff --git a/libc/private/bionic_lock.h b/libc/private/bionic_lock.h
index ec179d1..d70ba6c 100644
--- a/libc/private/bionic_lock.h
+++ b/libc/private/bionic_lock.h
@@ -72,6 +72,12 @@
   void unlock() {
     bool shared = process_shared; /* cache to local variable */
     if (atomic_exchange_explicit(&state, Unlocked, memory_order_release) == LockedWithWaiter) {
+      // The Lock object may have been deallocated between the atomic exchange and the futex wake
+      // call, so avoid accessing any fields of Lock here. In that case, the wake call may target
+      // unmapped memory or trigger a spurious futex wakeup. The same situation happens with
+      // pthread mutexes. References:
+      //  - https://lkml.org/lkml/2014/11/27/472
+      //  - http://austingroupbugs.net/view.php?id=811#c2267
       __futex_wake_ex(&state, shared, 1);
     }
   }
diff --git a/libc/private/bionic_malloc.h b/libc/private/bionic_malloc.h
index e8a6f6e..9c602ea 100644
--- a/libc/private/bionic_malloc.h
+++ b/libc/private/bionic_malloc.h
@@ -30,6 +30,22 @@
 
 #include <stdbool.h>
 
+// Structures for android_mallopt.
+
+typedef struct {
+  // Pointer to the buffer allocated by a call to M_GET_MALLOC_LEAK_INFO.
+  uint8_t* buffer;
+  // The size of the "info" buffer.
+  size_t overall_size;
+  // The size of a single entry.
+  size_t info_size;
+  // The sum of all allocations that have been tracked. Does not include
+  // any heap overhead.
+  size_t total_memory;
+  // The maximum number of backtrace entries.
+  size_t backtrace_size;
+} android_mallopt_leak_info_t;
+
 // Opcodes for android_mallopt.
 
 enum {
@@ -48,6 +64,26 @@
   // Called after the zygote forks to indicate this is a child.
   M_SET_ZYGOTE_CHILD = 4,
 #define M_SET_ZYGOTE_CHILD M_SET_ZYGOTE_CHILD
+
+  // Options to dump backtraces of allocations. These options only
+  // work when malloc debug has been enabled.
+
+  // Writes the backtrace information of all current allocations to a file.
+  // NOTE: arg_size has to be sizeof(FILE*) because FILE is an opaque type.
+  //   arg = FILE*
+  //   arg_size = sizeof(FILE*)
+  M_WRITE_MALLOC_LEAK_INFO_TO_FILE = 5,
+#define M_WRITE_MALLOC_LEAK_INFO_TO_FILE M_WRITE_MALLOC_LEAK_INFO_TO_FILE
+  // Get information about the backtraces of all
+  //   arg = android_mallopt_leak_info_t*
+  //   arg_size = sizeof(android_mallopt_leak_info_t)
+  M_GET_MALLOC_LEAK_INFO = 6,
+#define M_GET_MALLOC_LEAK_INFO M_GET_MALLOC_LEAK_INFO
+  // Free the memory allocated and returned by M_GET_MALLOC_LEAK_INFO.
+  //   arg = android_mallopt_leak_info_t*
+  //   arg_size = sizeof(android_mallopt_leak_info_t)
+  M_FREE_MALLOC_LEAK_INFO = 7,
+#define M_FREE_MALLOC_LEAK_INFO M_FREE_MALLOC_LEAK_INFO
 };
 
 // Manipulates bionic-specific handling of memory allocation APIs such as
diff --git a/libc/tools/generate-NOTICE.py b/libc/tools/generate-NOTICE.py
index 17429e1..7218445 100755
--- a/libc/tools/generate-NOTICE.py
+++ b/libc/tools/generate-NOTICE.py
@@ -1,7 +1,5 @@
 #!/usr/bin/env python
 # Run with directory arguments from any directory, with no special setup required.
-# Or:
-# for i in libc libdl libm linker libstdc++ ; do ./libc/tools/generate-NOTICE.py $i > $i/NOTICE ; done
 
 import ftplib
 import hashlib
diff --git a/libdl/MODULE_LICENSE_BSD b/libdl/MODULE_LICENSE_APACHE2
similarity index 100%
rename from libdl/MODULE_LICENSE_BSD
rename to libdl/MODULE_LICENSE_APACHE2
diff --git a/libdl/NOTICE b/libdl/NOTICE
new file mode 100644
index 0000000..d645695
--- /dev/null
+++ b/libdl/NOTICE
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/libdl/libdl_static.cpp b/libdl/libdl_static.cpp
index 7146762..0a36e6f 100644
--- a/libdl/libdl_static.cpp
+++ b/libdl/libdl_static.cpp
@@ -23,7 +23,7 @@
 }
 
 char* dlerror() {
-  return nullptr;
+  return const_cast<char*>("libdl.a is a stub --- use libdl.so instead");
 }
 
 void* dlsym(void* /*handle*/, const char* /*symbol*/) {
diff --git a/linker/MODULE_LICENSE_BSD b/linker/MODULE_LICENSE_APACHE2
similarity index 100%
rename from linker/MODULE_LICENSE_BSD
rename to linker/MODULE_LICENSE_APACHE2
diff --git a/linker/NOTICE b/linker/NOTICE
new file mode 100644
index 0000000..d645695
--- /dev/null
+++ b/linker/NOTICE
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
diff --git a/linker/linker.cpp b/linker/linker.cpp
index d62eaec..b59df73 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -1865,11 +1865,17 @@
 
     soinfo_list_t global_group = local_group_ns->get_global_group();
     bool linked = local_group.visit([&](soinfo* si) {
-      // Even though local group may contain accessible soinfos from other namesapces
+      // Even though local group may contain accessible soinfos from other namespaces
       // we should avoid linking them (because if they are not linked -> they
       // are in the local_group_roots and will be linked later).
       if (!si->is_linked() && si->get_primary_namespace() == local_group_ns) {
-        if (!si->link_image(global_group, local_group, extinfo, &relro_fd_offset) ||
+        const android_dlextinfo* link_extinfo = nullptr;
+        if (si == soinfos[0] || reserved_address_recursive) {
+          // Only forward extinfo for the first library unless the recursive
+          // flag is set.
+          link_extinfo = extinfo;
+        }
+        if (!si->link_image(global_group, local_group, link_extinfo, &relro_fd_offset) ||
             !get_cfi_shadow()->AfterLoad(si, solist_get_head())) {
           return false;
         }
diff --git a/tests/dlext_test.cpp b/tests/dlext_test.cpp
index 3af52d4..eed84a4 100644
--- a/tests/dlext_test.cpp
+++ b/tests/dlext_test.cpp
@@ -538,6 +538,26 @@
   tf.fd = extinfo_.relro_fd;
 }
 
+TEST_F(DlExtRelroSharingTest, CheckRelroSizes) {
+  TemporaryFile tf1, tf2;
+  ASSERT_NOERROR(close(tf1.fd));
+  ASSERT_NOERROR(close(tf2.fd));
+
+  ASSERT_NO_FATAL_FAILURE(CreateRelroFile(kLibNameRecursive, tf1.path, false));
+  struct stat no_recursive;
+  ASSERT_NOERROR(fstat(extinfo_.relro_fd, &no_recursive));
+  tf1.fd = extinfo_.relro_fd;
+
+  ASSERT_NO_FATAL_FAILURE(CreateRelroFile(kLibNameRecursive, tf2.path, true));
+  struct stat with_recursive;
+  ASSERT_NOERROR(fstat(extinfo_.relro_fd, &with_recursive));
+  tf2.fd = extinfo_.relro_fd;
+
+  // RELRO file should end up bigger when we use the recursive flag, since it
+  // includes data for more than one library.
+  ASSERT_GT(with_recursive.st_size, no_recursive.st_size);
+}
+
 TEST_F(DlExtRelroSharingTest, ChildWritesNoRelro) {
   TemporaryFile tf; // // Use tf to get an unique filename.
   ASSERT_NOERROR(close(tf.fd));
diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index 7b64401..0bf8e29 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -1843,10 +1843,25 @@
   DISALLOW_COPY_AND_ASSIGN(PthreadMutex);
 };
 
+static int UnlockFromAnotherThread(pthread_mutex_t* mutex) {
+  pthread_t thread;
+  pthread_create(&thread, nullptr, [](void* mutex_voidp) -> void* {
+    pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(mutex_voidp);
+    intptr_t result = pthread_mutex_unlock(mutex);
+    return reinterpret_cast<void*>(result);
+  }, mutex);
+  void* result;
+  EXPECT_EQ(0, pthread_join(thread, &result));
+  return reinterpret_cast<intptr_t>(result);
+};
+
 static void TestPthreadMutexLockNormal(int protocol) {
   PthreadMutex m(PTHREAD_MUTEX_NORMAL, protocol);
 
   ASSERT_EQ(0, pthread_mutex_lock(&m.lock));
+  if (protocol == PTHREAD_PRIO_INHERIT) {
+    ASSERT_EQ(EPERM, UnlockFromAnotherThread(&m.lock));
+  }
   ASSERT_EQ(0, pthread_mutex_unlock(&m.lock));
   ASSERT_EQ(0, pthread_mutex_trylock(&m.lock));
   ASSERT_EQ(EBUSY, pthread_mutex_trylock(&m.lock));
@@ -1857,6 +1872,7 @@
   PthreadMutex m(PTHREAD_MUTEX_ERRORCHECK, protocol);
 
   ASSERT_EQ(0, pthread_mutex_lock(&m.lock));
+  ASSERT_EQ(EPERM, UnlockFromAnotherThread(&m.lock));
   ASSERT_EQ(EDEADLK, pthread_mutex_lock(&m.lock));
   ASSERT_EQ(0, pthread_mutex_unlock(&m.lock));
   ASSERT_EQ(0, pthread_mutex_trylock(&m.lock));
@@ -1873,7 +1889,9 @@
   PthreadMutex m(PTHREAD_MUTEX_RECURSIVE, protocol);
 
   ASSERT_EQ(0, pthread_mutex_lock(&m.lock));
+  ASSERT_EQ(EPERM, UnlockFromAnotherThread(&m.lock));
   ASSERT_EQ(0, pthread_mutex_lock(&m.lock));
+  ASSERT_EQ(EPERM, UnlockFromAnotherThread(&m.lock));
   ASSERT_EQ(0, pthread_mutex_unlock(&m.lock));
   ASSERT_EQ(0, pthread_mutex_unlock(&m.lock));
   ASSERT_EQ(0, pthread_mutex_trylock(&m.lock));
diff --git a/tools/update_notice.sh b/tools/update_notice.sh
index 0b8a106..a309bc2 100755
--- a/tools/update_notice.sh
+++ b/tools/update_notice.sh
@@ -1,7 +1,7 @@
 #!/bin/bash
 DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 cd $DIR/..
-./libc/tools/generate-NOTICE.py libc libdl libm linker libstdc++ > libc/NOTICE
+./libc/tools/generate-NOTICE.py libc libm > libc/NOTICE
 
 git diff --exit-code HEAD libc/NOTICE
 exit $?