diff --git a/libc/Android.mk b/libc/Android.mk
index 620f438..868d159 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -130,6 +130,7 @@
     bionic/fchmodat.cpp \
     bionic/ffs.cpp \
     bionic/fgetxattr.cpp \
+    bionic/flistxattr.cpp \
     bionic/flockfile.cpp \
     bionic/fpclassify.cpp \
     bionic/fsetxattr.cpp \
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index 4890b89..23cc3b6 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -124,7 +124,7 @@
 void        sync(void)  all
 int         ___fsetxattr:fsetxattr(int, const char*, const void*, size_t, int) all
 ssize_t     ___fgetxattr:fgetxattr(int, const char*, void*, size_t) all
-ssize_t     flistxattr(int, char*, size_t) all
+ssize_t     ___flistxattr:flistxattr(int, char*, size_t) all
 int         fremovexattr(int, const char*) all
 
 int __getdents64:getdents64(unsigned int, struct dirent*, unsigned int)   arm,arm64,mips,mips64,x86,x86_64
diff --git a/libc/arch-arm/syscalls/flistxattr.S b/libc/arch-arm/syscalls/___flistxattr.S
similarity index 81%
rename from libc/arch-arm/syscalls/flistxattr.S
rename to libc/arch-arm/syscalls/___flistxattr.S
index ee09295..8ae8b7e 100644
--- a/libc/arch-arm/syscalls/flistxattr.S
+++ b/libc/arch-arm/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
 
 #include <private/bionic_asm.h>
 
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
     mov     ip, r7
     ldr     r7, =__NR_flistxattr
     swi     #0
@@ -11,4 +11,5 @@
     bxls    lr
     neg     r0, r0
     b       __set_errno_internal
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/arch-arm64/syscalls/flistxattr.S b/libc/arch-arm64/syscalls/___flistxattr.S
similarity index 78%
rename from libc/arch-arm64/syscalls/flistxattr.S
rename to libc/arch-arm64/syscalls/___flistxattr.S
index 8921bb4..02c8478 100644
--- a/libc/arch-arm64/syscalls/flistxattr.S
+++ b/libc/arch-arm64/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
 
 #include <private/bionic_asm.h>
 
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
     mov     x8, __NR_flistxattr
     svc     #0
 
@@ -11,4 +11,5 @@
     b.hi    __set_errno_internal
 
     ret
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/arch-mips/syscalls/flistxattr.S b/libc/arch-mips/syscalls/___flistxattr.S
similarity index 81%
rename from libc/arch-mips/syscalls/flistxattr.S
rename to libc/arch-mips/syscalls/___flistxattr.S
index 0b71532..5a4a53d 100644
--- a/libc/arch-mips/syscalls/flistxattr.S
+++ b/libc/arch-mips/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
 
 #include <private/bionic_asm.h>
 
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
     .set noreorder
     .cpload t9
     li v0, __NR_flistxattr
@@ -16,4 +16,5 @@
     j t9
     nop
     .set reorder
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/arch-mips64/syscalls/flistxattr.S b/libc/arch-mips64/syscalls/___flistxattr.S
similarity index 85%
rename from libc/arch-mips64/syscalls/flistxattr.S
rename to libc/arch-mips64/syscalls/___flistxattr.S
index 1d5b1b0..586bcf7 100644
--- a/libc/arch-mips64/syscalls/flistxattr.S
+++ b/libc/arch-mips64/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
 
 #include <private/bionic_asm.h>
 
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
     .set push
     .set noreorder
     li v0, __NR_flistxattr
@@ -22,4 +22,5 @@
     j t9
     move ra, t0
     .set pop
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/arch-x86/syscalls/flistxattr.S b/libc/arch-x86/syscalls/___flistxattr.S
similarity index 90%
rename from libc/arch-x86/syscalls/flistxattr.S
rename to libc/arch-x86/syscalls/___flistxattr.S
index fc81a37..a67967b 100644
--- a/libc/arch-x86/syscalls/flistxattr.S
+++ b/libc/arch-x86/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
 
 #include <private/bionic_asm.h>
 
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
     pushl   %ebx
     .cfi_def_cfa_offset 8
     .cfi_rel_offset ebx, 0
@@ -28,4 +28,5 @@
     popl    %ecx
     popl    %ebx
     ret
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/arch-x86_64/syscalls/flistxattr.S b/libc/arch-x86_64/syscalls/___flistxattr.S
similarity index 80%
rename from libc/arch-x86_64/syscalls/flistxattr.S
rename to libc/arch-x86_64/syscalls/___flistxattr.S
index aa02db1..b4695cc 100644
--- a/libc/arch-x86_64/syscalls/flistxattr.S
+++ b/libc/arch-x86_64/syscalls/___flistxattr.S
@@ -2,7 +2,7 @@
 
 #include <private/bionic_asm.h>
 
-ENTRY(flistxattr)
+ENTRY(___flistxattr)
     movl    $__NR_flistxattr, %eax
     syscall
     cmpq    $-MAX_ERRNO, %rax
@@ -12,4 +12,5 @@
     call    __set_errno_internal
 1:
     ret
-END(flistxattr)
+END(___flistxattr)
+.hidden ___flistxattr
diff --git a/libc/bionic/flistxattr.cpp b/libc/bionic/flistxattr.cpp
new file mode 100644
index 0000000..05a96d2
--- /dev/null
+++ b/libc/bionic/flistxattr.cpp
@@ -0,0 +1,59 @@
+/*
+ * 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 <sys/stat.h>
+#include <sys/types.h>
+#include <sys/xattr.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+
+extern "C" ssize_t ___flistxattr(int, char*, size_t);
+
+ssize_t flistxattr(int fd, char *list, size_t size) {
+  int saved_errno = errno;
+  ssize_t result = ___flistxattr(fd, list, size);
+
+  if ((result != -1) || (errno != EBADF)) {
+    return result;
+  }
+
+  // fd could be an O_PATH file descriptor, and the kernel
+  // may not directly support fgetxattr() on such a file descriptor.
+  // Use /proc/self/fd instead to emulate this support.
+  int fd_flag = fcntl(fd, F_GETFL);
+  if ((fd_flag == -1) || ((fd_flag & O_PATH) == 0)) {
+    errno = EBADF;
+    return -1;
+  }
+
+  char buf[40];
+  snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fd);
+  errno = saved_errno;
+  return listxattr(buf, list, size);
+}
diff --git a/libc/bionic/pthread_mutex.cpp b/libc/bionic/pthread_mutex.cpp
index 4fec753..851fc3d 100644
--- a/libc/bionic/pthread_mutex.cpp
+++ b/libc/bionic/pthread_mutex.cpp
@@ -501,6 +501,12 @@
 }
 
 int pthread_mutex_lock(pthread_mutex_t* mutex_interface) {
+#if !defined(__LP64__)
+    if (mutex_interface == NULL) {
+        return EINVAL;
+    }
+#endif
+
     pthread_mutex_internal_t* mutex = __get_internal_mutex(mutex_interface);
 
     uint16_t old_state = atomic_load_explicit(&mutex->state, memory_order_relaxed);
@@ -516,6 +522,12 @@
 }
 
 int pthread_mutex_unlock(pthread_mutex_t* mutex_interface) {
+#if !defined(__LP64__)
+    if (mutex_interface == NULL) {
+        return EINVAL;
+    }
+#endif
+
     pthread_mutex_internal_t* mutex = __get_internal_mutex(mutex_interface);
 
     uint16_t old_state = atomic_load_explicit(&mutex->state, memory_order_relaxed);
diff --git a/libc/include/android/dlext.h b/libc/include/android/dlext.h
index f10a8a2..40f610f 100644
--- a/libc/include/android/dlext.h
+++ b/libc/include/android/dlext.h
@@ -73,6 +73,13 @@
    */
   ANDROID_DLEXT_FORCE_LOAD = 0x40,
 
+  /* When set, if the minimum p_vaddr of the ELF file's PT_LOAD segments is non-zero,
+   * the dynamic linker will load it at that address.
+   *
+   * This flag is for ART internal use only.
+   */
+  ANDROID_DLEXT_FORCE_FIXED_VADDR = 0x80,
+
   /* Mask of valid bits */
   ANDROID_DLEXT_VALID_FLAG_BITS       = ANDROID_DLEXT_RESERVED_ADDRESS |
                                         ANDROID_DLEXT_RESERVED_ADDRESS_HINT |
@@ -80,7 +87,8 @@
                                         ANDROID_DLEXT_USE_RELRO |
                                         ANDROID_DLEXT_USE_LIBRARY_FD |
                                         ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET |
-                                        ANDROID_DLEXT_FORCE_LOAD,
+                                        ANDROID_DLEXT_FORCE_LOAD |
+                                        ANDROID_DLEXT_FORCE_FIXED_VADDR,
 };
 
 typedef struct {
diff --git a/libc/include/pthread.h b/libc/include/pthread.h
index 26d68e4..260ae5b 100644
--- a/libc/include/pthread.h
+++ b/libc/include/pthread.h
@@ -176,10 +176,18 @@
 
 int pthread_mutex_destroy(pthread_mutex_t*) __nonnull((1));
 int pthread_mutex_init(pthread_mutex_t*, const pthread_mutexattr_t*) __nonnull((1));
+#if !defined(__LP64__)
+int pthread_mutex_lock(pthread_mutex_t*) /* __nonnull((1)) */;
+#else
 int pthread_mutex_lock(pthread_mutex_t*) __nonnull((1));
+#endif
 int pthread_mutex_timedlock(pthread_mutex_t*, const struct timespec*) __nonnull((1, 2));
 int pthread_mutex_trylock(pthread_mutex_t*) __nonnull((1));
+#if !defined(__LP4__)
+int pthread_mutex_unlock(pthread_mutex_t*) /* __nonnull((1)) */;
+#else
 int pthread_mutex_unlock(pthread_mutex_t*) __nonnull((1));
+#endif
 
 int pthread_once(pthread_once_t*, void (*)(void)) __nonnull((1, 2));
 
diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp
index 638c9d6..f586b08 100644
--- a/linker/linker_phdr.cpp
+++ b/linker/linker_phdr.cpp
@@ -316,6 +316,8 @@
   void* start;
   size_t reserved_size = 0;
   bool reserved_hint = true;
+  // Assume position independent executable by default.
+  uint8_t* mmap_hint = nullptr;
 
   if (extinfo != nullptr) {
     if (extinfo->flags & ANDROID_DLEXT_RESERVED_ADDRESS) {
@@ -324,6 +326,10 @@
     } else if (extinfo->flags & ANDROID_DLEXT_RESERVED_ADDRESS_HINT) {
       reserved_size = extinfo->reserved_size;
     }
+
+    if ((extinfo->flags & ANDROID_DLEXT_FORCE_FIXED_VADDR) != 0) {
+      mmap_hint = addr;
+    }
   }
 
   if (load_size_ > reserved_size) {
@@ -333,7 +339,7 @@
       return false;
     }
     int mmap_flags = MAP_PRIVATE | MAP_ANONYMOUS;
-    start = mmap(nullptr, load_size_, PROT_NONE, mmap_flags, -1, 0);
+    start = mmap(mmap_hint, load_size_, PROT_NONE, mmap_flags, -1, 0);
     if (start == MAP_FAILED) {
       DL_ERR("couldn't reserve %zd bytes of address space for \"%s\"", load_size_, name_);
       return false;
diff --git a/tests/pthread_test.cpp b/tests/pthread_test.cpp
index e55ed37..eeb1541 100644
--- a/tests/pthread_test.cpp
+++ b/tests/pthread_test.cpp
@@ -1537,3 +1537,37 @@
   GTEST_LOG_(INFO) << "This test tests bionic implementation details.";
 #endif
 }
+
+TEST(pthread, pthread_mutex_lock_null_32) {
+#if defined(__BIONIC__) && !defined(__LP64__)
+  ASSERT_EQ(EINVAL, pthread_mutex_lock(NULL));
+#else
+  GTEST_LOG_(INFO) << "This test tests bionic implementation details on 32 bit devices.";
+#endif
+}
+
+TEST(pthread, pthread_mutex_unlock_null_32) {
+#if defined(__BIONIC__) && !defined(__LP64__)
+  ASSERT_EQ(EINVAL, pthread_mutex_unlock(NULL));
+#else
+  GTEST_LOG_(INFO) << "This test tests bionic implementation details on 32 bit devices.";
+#endif
+}
+
+TEST_F(pthread_DeathTest, pthread_mutex_lock_null_64) {
+#if defined(__BIONIC__) && defined(__LP64__)
+  pthread_mutex_t* null_value = nullptr;
+  ASSERT_EXIT(pthread_mutex_lock(null_value), testing::KilledBySignal(SIGSEGV), "");
+#else
+  GTEST_LOG_(INFO) << "This test tests bionic implementation details on 64 bit devices.";
+#endif
+}
+
+TEST_F(pthread_DeathTest, pthread_mutex_unlock_null_64) {
+#if defined(__BIONIC__) && defined(__LP64__)
+  pthread_mutex_t* null_value = nullptr;
+  ASSERT_EXIT(pthread_mutex_unlock(null_value), testing::KilledBySignal(SIGSEGV), "");
+#else
+  GTEST_LOG_(INFO) << "This test tests bionic implementation details on 64 bit devices.";
+#endif
+}
diff --git a/tests/sys_xattr_test.cpp b/tests/sys_xattr_test.cpp
index 1842682..113ec26 100644
--- a/tests/sys_xattr_test.cpp
+++ b/tests/sys_xattr_test.cpp
@@ -80,6 +80,7 @@
   ASSERT_EQ(-1, res);
   ASSERT_EQ(EBADF, errno);
 #endif
+  close(fd);
 }
 
 TEST(sys_xattr, fsetxattr_with_opath_toosmall) {
@@ -97,4 +98,32 @@
   ASSERT_EQ(-1, res);
   ASSERT_EQ(EBADF, errno);
 #endif
+  close(fd);
+}
+
+TEST(sys_xattr, flistattr) {
+  TemporaryFile tf;
+  char buf[65536];  // 64kB is max possible xattr list size. See "man 7 xattr".
+  ASSERT_EQ(0, fsetxattr(tf.fd, "user.foo", "bar", 4, 0));
+  ssize_t result = flistxattr(tf.fd, buf, sizeof(buf));
+  ASSERT_TRUE(result >= 9);
+  ASSERT_TRUE(memmem(buf, sizeof(buf), "user.foo", 9) != NULL);
+}
+
+TEST(sys_xattr, flistattr_opath) {
+  TemporaryFile tf;
+  char buf[65536];  // 64kB is max possible xattr list size. See "man 7 xattr".
+  ASSERT_EQ(0, fsetxattr(tf.fd, "user.foo", "bar", 4, 0));
+  int fd = open(tf.filename, O_PATH);
+  ASSERT_NE(-1, fd);
+  ssize_t res = flistxattr(fd, buf, sizeof(buf));
+#if defined(__BIONIC__)
+  ASSERT_TRUE(res >= 9);
+  ASSERT_TRUE(static_cast<size_t>(res) <= sizeof(buf));
+  ASSERT_TRUE(memmem(buf, res, "user.foo", 9) != NULL);
+#else
+  ASSERT_EQ(-1, res);
+  ASSERT_EQ(EBADF, errno);
+#endif
+  close(fd);
 }
diff --git a/tools/relocation_packer/Android.mk b/tools/relocation_packer/Android.mk
index 94c946c..35c97a8 100644
--- a/tools/relocation_packer/Android.mk
+++ b/tools/relocation_packer/Android.mk
@@ -14,6 +14,7 @@
 # limitations under the License.
 #
 
+ifeq ($(HOST_OS),linux)
 common_cppflags := -Wall -Wextra -Wunused -Werror -Wold-style-cast
 
 LOCAL_PATH := $(call my-dir)
@@ -101,3 +102,5 @@
 $(eval $(call copy-test-library,elf_file_unittest_relocs_x64_packed.so))
 $(eval $(call copy-test-library,elf_file_unittest_relocs_mips32.so))
 $(eval $(call copy-test-library,elf_file_unittest_relocs_mips32_packed.so))
+
+endif