diff --git a/build/bionic.go b/build/bionic.go
index 93c2494..54ad10b 100644
--- a/build/bionic.go
+++ b/build/bionic.go
@@ -89,6 +89,9 @@
 	// Symlinks to the mountpoints from the system and recovery partitions
 	// Symlinks names will have the same suffix as the mount point
 	Symlinks []string
+
+	// List of sanitizer names that this APEX is enabled for
+	SanitizerNames []string `blueprint:"mutated"`
 }
 
 type dependencyTag struct {
@@ -98,6 +101,31 @@
 
 var mountsourceTag = dependencyTag{name: "mountsource"}
 
+
+func (m *bionicMountpoint) EnableSanitizer(sanitizerName string) {
+	if !android.InList(sanitizerName, m.properties.SanitizerNames) {
+		m.properties.SanitizerNames = append(m.properties.SanitizerNames, sanitizerName)
+	}
+}
+
+func (m *bionicMountpoint) IsSanitizerEnabled(ctx android.BaseModuleContext, sanitizerName string) bool {
+	if android.InList(sanitizerName, m.properties.SanitizerNames) {
+		return true
+	}
+
+	// Then follow the global setting
+	globalSanitizerNames := []string{}
+	if m.Host() {
+		globalSanitizerNames = ctx.Config().SanitizeHost()
+	} else {
+		arches := ctx.Config().SanitizeDeviceArch()
+		if len(arches) == 0 || android.InList(m.Arch().ArchType.Name, arches) {
+			globalSanitizerNames = ctx.Config().SanitizeDevice()
+		}
+	}
+	return android.InList(sanitizerName, globalSanitizerNames)
+}
+
 func (m *bionicMountpoint) DepsMutator(ctx android.BottomUpMutatorContext) {
 	if Bool(m.properties.Library) == Bool(m.properties.Binary) {
 		ctx.ModuleErrorf("either binary or library must be set to true")
diff --git a/libc/Android.bp b/libc/Android.bp
index 1487975..262d951 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -77,9 +77,14 @@
     native_coverage: false,
     recovery_available: true,
 
-    // TODO(ivanlozano): Remove after b/118321713
-    no_libcrt: true,
-    xom: false,
+    arch: {
+        x86: {
+            no_libcrt: true,
+        },
+        x86_64: {
+            no_libcrt: true,
+        },
+    },
 }
 
 // ========================================================
@@ -765,7 +770,7 @@
                 "arch-arm/bionic/atomics_arm.c",
                 "arch-arm/bionic/__bionic_clone.S",
                 "arch-arm/bionic/_exit_with_stack_teardown.S",
-                "arch-arm/bionic/libgcc_compat.c",
+                "arch-arm/bionic/libcrt_compat.c",
                 "arch-arm/bionic/popcount_tab.c",
                 "arch-arm/bionic/__restore.S",
                 "arch-arm/bionic/setjmp.S",
@@ -849,7 +854,7 @@
                 "arch-mips/bionic/__bionic_clone.S",
                 "arch-mips/bionic/cacheflush.cpp",
                 "arch-mips/bionic/_exit_with_stack_teardown.S",
-                "arch-mips/bionic/libgcc_compat.c",
+                "arch-mips/bionic/libcrt_compat.c",
                 "arch-mips/bionic/setjmp.S",
                 "arch-mips/bionic/syscall.S",
                 "arch-mips/bionic/vfork.S",
@@ -919,7 +924,7 @@
 
                 "arch-x86/bionic/__bionic_clone.S",
                 "arch-x86/bionic/_exit_with_stack_teardown.S",
-                "arch-x86/bionic/libgcc_compat.c",
+                "arch-x86/bionic/libcrt_compat.c",
                 "arch-x86/bionic/__restore.S",
                 "arch-x86/bionic/setjmp.S",
                 "arch-x86/bionic/syscall.S",
diff --git a/libc/arch-arm/bionic/libgcc_compat.c b/libc/arch-arm/bionic/libcrt_compat.c
similarity index 95%
rename from libc/arch-arm/bionic/libgcc_compat.c
rename to libc/arch-arm/bionic/libcrt_compat.c
index abd1422..22a3387 100644
--- a/libc/arch-arm/bionic/libgcc_compat.c
+++ b/libc/arch-arm/bionic/libcrt_compat.c
@@ -90,6 +90,8 @@
 extern char __floatunsisf;
 extern char __gedf2;
 extern char __gtdf2;
+extern char __gnu_ldivmod_helper;
+extern char __gnu_uldivmod_helper;
 extern char __ledf2;
 extern char __ltdf2;
 extern char __muldf3;
@@ -101,10 +103,11 @@
 extern char __subdf3;
 extern char __subsf3;
 extern char __truncdfsf2;
+extern char __udivdi3;
 extern char __unorddf2;
 extern char __unordsf2;
 
-void* __bionic_libgcc_compat_symbols[] = {
+void* __bionic_libcrt_compat_symbols[] = {
     &__adddf3,
     &__addsf3,
     &__aeabi_cdcmpeq,
@@ -169,6 +172,8 @@
     &__floatunsisf,
     &__gedf2,
     &__gtdf2,
+    &__gnu_ldivmod_helper,
+    &__gnu_uldivmod_helper,
     &__ledf2,
     &__ltdf2,
     &__muldf3,
@@ -180,6 +185,7 @@
     &__subdf3,
     &__subsf3,
     &__truncdfsf2,
+    &__udivdi3,
     &__unorddf2,
     &__unordsf2,
 };
diff --git a/libc/arch-mips/bionic/libgcc_compat.c b/libc/arch-mips/bionic/libcrt_compat.c
similarity index 97%
rename from libc/arch-mips/bionic/libgcc_compat.c
rename to libc/arch-mips/bionic/libcrt_compat.c
index 1a0f566..cfa41f2 100644
--- a/libc/arch-mips/bionic/libgcc_compat.c
+++ b/libc/arch-mips/bionic/libcrt_compat.c
@@ -32,7 +32,7 @@
 extern char __udivdi3;
 extern char __umoddi3;
 
-void* __bionic_libgcc_compat_symbols[] = {
+void* __bionic_libcrt_compat_symbols[] = {
     &__divdi3,
     &__moddi3,
     &__popcountsi2,
diff --git a/libc/arch-x86/bionic/libgcc_compat.c b/libc/arch-x86/bionic/libcrt_compat.c
similarity index 97%
rename from libc/arch-x86/bionic/libgcc_compat.c
rename to libc/arch-x86/bionic/libcrt_compat.c
index 1a0f566..cfa41f2 100644
--- a/libc/arch-x86/bionic/libgcc_compat.c
+++ b/libc/arch-x86/bionic/libcrt_compat.c
@@ -32,7 +32,7 @@
 extern char __udivdi3;
 extern char __umoddi3;
 
-void* __bionic_libgcc_compat_symbols[] = {
+void* __bionic_libcrt_compat_symbols[] = {
     &__divdi3,
     &__moddi3,
     &__popcountsi2,
diff --git a/libc/async_safe/Android.bp b/libc/async_safe/Android.bp
index a54d3b0..6ae1c42 100644
--- a/libc/async_safe/Android.bp
+++ b/libc/async_safe/Android.bp
@@ -12,7 +12,19 @@
     recovery_available: true,
 
     include_dirs: ["bionic/libc"],
-    header_libs: ["libc_headers"],
+    header_libs: ["libc_headers", "liblog_headers"],
 
     export_include_dirs: ["include"],
+    export_header_lib_headers: ["liblog_headers"],
+    stl: "none",
+}
+
+cc_library_headers {
+    name: "libasync_safe_headers",
+    recovery_available: true,
+
+    export_include_dirs: ["include"],
+
+    system_shared_libs: [],
+    stl: "none",
 }
diff --git a/libc/arch-mips/bionic/libgcc_compat.c b/libc/async_safe/include/async_safe/CHECK.h
similarity index 74%
copy from libc/arch-mips/bionic/libgcc_compat.c
copy to libc/async_safe/include/async_safe/CHECK.h
index 1a0f566..bec89a3 100644
--- a/libc/arch-mips/bionic/libgcc_compat.c
+++ b/libc/async_safe/include/async_safe/CHECK.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2016 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
@@ -26,16 +26,22 @@
  * SUCH DAMAGE.
  */
 
-extern char __divdi3;
-extern char __moddi3;
-extern char __popcountsi2;
-extern char __udivdi3;
-extern char __umoddi3;
+#pragma once
 
-void* __bionic_libgcc_compat_symbols[] = {
-    &__divdi3,
-    &__moddi3,
-    &__popcountsi2,
-    &__udivdi3,
-    &__umoddi3,
-};
+#include <sys/cdefs.h>
+
+#include <async_safe/log.h>
+
+__BEGIN_DECLS
+
+// TODO: replace this with something more like <android-base/logging.h>'s family of macros.
+
+#define CHECK(predicate) \
+  do { \
+    if (!(predicate)) { \
+      async_safe_fatal("%s:%d: %s CHECK '" #predicate "' failed", \
+          __FILE__, __LINE__, __FUNCTION__); \
+    } \
+  } while(0)
+
+__END_DECLS
diff --git a/libc/async_safe/include/async_safe/log.h b/libc/async_safe/include/async_safe/log.h
index df68062..0e02ea7 100644
--- a/libc/async_safe/include/async_safe/log.h
+++ b/libc/async_safe/include/async_safe/log.h
@@ -34,36 +34,14 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+// This file is an alternative to <android/log.h>, but reuses
+// `android_LogPriority` and should not have conflicting identifiers.
+#include <android/log.h>
+
 // These functions do not allocate memory to send data to the log.
 
 __BEGIN_DECLS
 
-enum {
-  ANDROID_LOG_UNKNOWN = 0,
-  ANDROID_LOG_DEFAULT,    /* only for SetMinPriority() */
-
-  ANDROID_LOG_VERBOSE,
-  ANDROID_LOG_DEBUG,
-  ANDROID_LOG_INFO,
-  ANDROID_LOG_WARN,
-  ANDROID_LOG_ERROR,
-  ANDROID_LOG_FATAL,
-
-  ANDROID_LOG_SILENT,     /* only for SetMinPriority(); must be last */
-};
-
-enum {
-  LOG_ID_MIN = 0,
-
-  LOG_ID_MAIN = 0,
-  LOG_ID_RADIO = 1,
-  LOG_ID_EVENTS = 2,
-  LOG_ID_SYSTEM = 3,
-  LOG_ID_CRASH = 4,
-
-  LOG_ID_MAX
-};
-
 // Formats a message to the log (priority 'fatal'), then aborts.
 // Implemented as a macro so that async_safe_fatal isn't on the stack when we crash:
 // we appear to go straight from the caller to abort, saving an uninteresting stack
@@ -91,16 +69,8 @@
 
 int async_safe_format_fd(int fd, const char* format , ...) __printflike(2, 3);
 int async_safe_format_fd_va_list(int fd, const char* format, va_list args);
-int async_safe_format_log(int pri, const char* tag, const char* fmt, ...) __printflike(3, 4);
-int async_safe_format_log_va_list(int pri, const char* tag, const char* fmt, va_list ap);
-int async_safe_write_log(int pri, const char* tag, const char* msg);
-
-#define CHECK(predicate) \
-  do { \
-    if (!(predicate)) { \
-      async_safe_fatal("%s:%d: %s CHECK '" #predicate "' failed", \
-          __FILE__, __LINE__, __FUNCTION__); \
-    } \
-  } while(0)
+int async_safe_format_log(int priority, const char* tag, const char* fmt, ...) __printflike(3, 4);
+int async_safe_format_log_va_list(int priority, const char* tag, const char* fmt, va_list ap);
+int async_safe_write_log(int priority, const char* tag, const char* msg);
 
 __END_DECLS
diff --git a/libc/bionic/bionic_allocator.cpp b/libc/bionic/bionic_allocator.cpp
index d9302ad..da0f7d0 100644
--- a/libc/bionic/bionic_allocator.cpp
+++ b/libc/bionic/bionic_allocator.cpp
@@ -38,6 +38,7 @@
 #include <new>
 
 #include <async_safe/log.h>
+#include <async_safe/CHECK.h>
 
 #include "private/bionic_macros.h"
 #include "private/bionic_page.h"
diff --git a/libc/bionic/malloc_common_dynamic.cpp b/libc/bionic/malloc_common_dynamic.cpp
index 1c3f53f..ce3e761 100644
--- a/libc/bionic/malloc_common_dynamic.cpp
+++ b/libc/bionic/malloc_common_dynamic.cpp
@@ -303,23 +303,25 @@
   return true;
 }
 
-static void InstallHooks(libc_globals* globals, const char* options, const char* prefix,
+static bool InstallHooks(libc_globals* globals, const char* options, const char* prefix,
                          const char* shared_lib) {
   void* impl_handle = LoadSharedLibrary(shared_lib, prefix, &globals->malloc_dispatch_table);
   if (impl_handle == nullptr) {
-    return;
+    return false;
   }
 
   init_func_t init_func = reinterpret_cast<init_func_t>(gFunctions[FUNC_INITIALIZE]);
   if (!init_func(&__libc_malloc_default_dispatch, &gMallocLeakZygoteChild, options)) {
     error_log("%s: failed to enable malloc %s", getprogname(), prefix);
     ClearGlobalFunctions();
-    return;
+    return false;
   }
 
   if (!FinishInstallHooks(globals, options, prefix)) {
     dlclose(impl_handle);
+    return false;
   }
+  return true;
 }
 
 // Initializes memory allocation framework once per process.
@@ -329,16 +331,25 @@
 
   // Prefer malloc debug since it existed first and is a more complete
   // malloc interceptor than the hooks.
+  bool hook_installed = false;
   if (CheckLoadMallocDebug(&options)) {
-    InstallHooks(globals, options, kDebugPrefix, kDebugSharedLib);
+    hook_installed = InstallHooks(globals, options, kDebugPrefix, kDebugSharedLib);
   } else if (CheckLoadMallocHooks(&options)) {
-    InstallHooks(globals, options, kHooksPrefix, kHooksSharedLib);
-  } else if (HeapprofdShouldLoad()) {
-    HeapprofdInstallHooksAtInit(globals);
+    hook_installed = InstallHooks(globals, options, kHooksPrefix, kHooksSharedLib);
   }
 
-  // Install this last to avoid as many race conditions as possible.
-  HeapprofdInstallSignalHandler();
+  if (!hook_installed) {
+    if (HeapprofdShouldLoad()) {
+      HeapprofdInstallHooksAtInit(globals);
+    }
+
+    // Install this last to avoid as many race conditions as possible.
+    HeapprofdInstallSignalHandler();
+  } else {
+    // Install a signal handler that prints an error since we don't support
+    // heapprofd and any other hook to be installed at the same time.
+    HeapprofdInstallErrorSignalHandler();
+  }
 }
 
 // Initializes memory allocation framework.
diff --git a/libc/bionic/malloc_heapprofd.cpp b/libc/bionic/malloc_heapprofd.cpp
index fb7266a..c492bac 100644
--- a/libc/bionic/malloc_heapprofd.cpp
+++ b/libc/bionic/malloc_heapprofd.cpp
@@ -211,6 +211,16 @@
   sigaction(kHeapprofdSignal, &action, nullptr);
 }
 
+static void DisplayError(int) {
+  error_log("Cannot install heapprofd while malloc debug/malloc hooks are enabled.");
+}
+
+void HeapprofdInstallErrorSignalHandler() {
+  struct sigaction action = {};
+  action.sa_handler = DisplayError;
+  sigaction(kHeapprofdSignal, &action, nullptr);
+}
+
 static void CommonInstallHooks(libc_globals* globals) {
   void* impl_handle = atomic_load(&gHeapprofdHandle);
   bool reusing_handle = impl_handle != nullptr;
diff --git a/libc/bionic/malloc_heapprofd.h b/libc/bionic/malloc_heapprofd.h
index 91188b9..5a766fc 100644
--- a/libc/bionic/malloc_heapprofd.h
+++ b/libc/bionic/malloc_heapprofd.h
@@ -38,4 +38,6 @@
 
 void HeapprofdInstallSignalHandler();
 
+void HeapprofdInstallErrorSignalHandler();
+
 bool HeapprofdMallopt(int optcode, void* arg, size_t arg_size);
diff --git a/libc/bionic/system_property_set.cpp b/libc/bionic/system_property_set.cpp
index bc3ba76..c508db1 100644
--- a/libc/bionic/system_property_set.cpp
+++ b/libc/bionic/system_property_set.cpp
@@ -42,6 +42,7 @@
 #include <unistd.h>
 
 #include <async_safe/log.h>
+#include <async_safe/CHECK.h>
 
 #include "private/bionic_defs.h"
 #include "private/bionic_macros.h"
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index 6a6ea7d..62aea27 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1561,7 +1561,7 @@
     __ashldi3; # arm
     __ashrdi3; # arm
     __bionic_brk; # arm x86 mips
-    __bionic_libgcc_compat_symbols; # arm x86
+    __bionic_libcrt_compat_symbols; # arm x86
     __cmpdf2; # arm
     __divdf3; # arm
     __divdi3; # arm x86 mips
diff --git a/libc/malloc_debug/PointerData.cpp b/libc/malloc_debug/PointerData.cpp
index 638061b..6e9d24f 100644
--- a/libc/malloc_debug/PointerData.cpp
+++ b/libc/malloc_debug/PointerData.cpp
@@ -266,12 +266,12 @@
   error_log("  hash_index %zu does not have matching frame data.", hash_index);
 }
 
-void PointerData::LogFreeError(const FreePointerInfoType& info, size_t usable_size) {
+void PointerData::LogFreeError(const FreePointerInfoType& info, size_t max_cmp_bytes) {
   error_log(LOG_DIVIDER);
   uint8_t* memory = reinterpret_cast<uint8_t*>(info.pointer);
   error_log("+++ ALLOCATION %p USED AFTER FREE", memory);
   uint8_t fill_free_value = g_debug->config().fill_free_value();
-  for (size_t i = 0; i < usable_size; i++) {
+  for (size_t i = 0; i < max_cmp_bytes; i++) {
     if (memory[i] != fill_free_value) {
       error_log("  allocation[%zu] = 0x%02x (expected 0x%02x)", i, memory[i], fill_free_value);
     }
@@ -314,11 +314,12 @@
   size_t bytes = (usable_size < g_debug->config().fill_on_free_bytes())
                      ? usable_size
                      : g_debug->config().fill_on_free_bytes();
+  size_t max_cmp_bytes = bytes;
   const uint8_t* memory = reinterpret_cast<const uint8_t*>(info.pointer);
   while (bytes > 0) {
     size_t bytes_to_cmp = (bytes < g_cmp_mem.size()) ? bytes : g_cmp_mem.size();
     if (memcmp(memory, g_cmp_mem.data(), bytes_to_cmp) != 0) {
-      LogFreeError(info, usable_size);
+      LogFreeError(info, max_cmp_bytes);
     }
     bytes -= bytes_to_cmp;
     memory = &memory[bytes_to_cmp];
diff --git a/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp b/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
index 44f9795..6da95ca 100644
--- a/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
+++ b/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
@@ -990,6 +990,35 @@
   ASSERT_STREQ("", getFakeLogPrint().c_str());
 }
 
+TEST_F(MallocDebugTest, free_track_pointer_modified_after_free) {
+  Init("free_track=4 fill_on_free=2 free_track_backtrace_num_frames=0");
+
+  void* pointers[5];
+  for (size_t i = 0; i < sizeof(pointers) / sizeof(void*); i++) {
+    pointers[i] = debug_malloc(100);
+    ASSERT_TRUE(pointers[i] != nullptr);
+    memset(pointers[i], 0, 100);
+  }
+
+  debug_free(pointers[0]);
+
+  // overwrite the whole pointer, only expect errors on the fill bytes we check.
+  memset(pointers[0], 0x20, 100);
+
+  for (size_t i = 1; i < sizeof(pointers) / sizeof(void*); i++) {
+    debug_free(pointers[i]);
+  }
+
+  std::string expected_log(DIVIDER);
+  expected_log += android::base::StringPrintf("6 malloc_debug +++ ALLOCATION %p USED AFTER FREE\n",
+                                              pointers[0]);
+  expected_log += "6 malloc_debug   allocation[0] = 0x20 (expected 0xef)\n";
+  expected_log += "6 malloc_debug   allocation[1] = 0x20 (expected 0xef)\n";
+  expected_log += DIVIDER;
+  ASSERT_STREQ("", getFakeLogBuf().c_str());
+  ASSERT_STREQ(expected_log.c_str(), getFakeLogPrint().c_str());
+}
+
 TEST_F(MallocDebugTest, get_malloc_leak_info_invalid) {
   Init("fill");
 
diff --git a/libc/symbol_ordering b/libc/symbol_ordering
index c39fac5..6fcc09e 100644
--- a/libc/symbol_ordering
+++ b/libc/symbol_ordering
@@ -3,8 +3,6 @@
 # symbols by size, we usually have less dirty pages at runtime, because small
 # symbols are grouped together.
 
-je_background_thread_enabled_state
-je_can_enable_background_thread
 _ZZ17__find_icu_symbolPKcE9found_icu
 _ZL24gHeapprofdInitInProgress
 _ZL27gHeapprofdInitHookInstalled
@@ -19,7 +17,6 @@
 had_conf_error
 malloc_slow_flags
 je_opt_background_thread
-background_thread_enabled_at_fork
 ctl_initialized
 je_log_init_done
 mmap_flags
@@ -70,8 +67,6 @@
 seed48.sseed
 ether_aton.addr
 je_background_thread_info
-je_max_background_threads
-je_n_background_threads
 je_malloc_message
 je_tcache_bin_info
 je_tcache_maxclass
@@ -92,7 +87,6 @@
 je_opt_muzzy_decay_ms
 dirty_decay_ms_default.0
 muzzy_decay_ms_default.0
-pthread_create_fptr
 b0
 ctl_arenas
 ctl_stats
diff --git a/libc/system_properties/Android.bp b/libc/system_properties/Android.bp
index f94cda9..911afb1 100644
--- a/libc/system_properties/Android.bp
+++ b/libc/system_properties/Android.bp
@@ -12,8 +12,8 @@
     whole_static_libs: [
         "libpropertyinfoparser",
     ],
-    static_libs: [
-        "libasync_safe",
+    header_libs: [
+        "libasync_safe_headers",
     ],
 
     include_dirs: [
diff --git a/libdl/Android.bp b/libdl/Android.bp
index 43ddbfe..642cc7a 100644
--- a/libdl/Android.bp
+++ b/libdl/Android.bp
@@ -92,6 +92,8 @@
 
     nocrt: true,
     system_shared_libs: [],
+
+    // Opt out of native_coverage when opting out of system_shared_libs
     native_coverage: false,
 
     // This is placeholder library the actual implementation is (currently)
diff --git a/linker/Android.bp b/linker/Android.bp
index fed921d..613be3d 100644
--- a/linker/Android.bp
+++ b/linker/Android.bp
@@ -296,6 +296,10 @@
         },
     },
     system_shared_libs: [],
+
+    // Opt out of native_coverage when opting out of system_shared_libs
+    native_coverage: false,
+
     target: {
         android: {
             static_libs: ["libdebuggerd_handler_fallback"],
@@ -364,7 +368,46 @@
     nocrt: true,
     system_shared_libs: [],
 
+    // Opt out of native_coverage when opting out of system_shared_libs
+    native_coverage: false,
+
     sanitize: {
         never: true,
     },
 }
+
+cc_test {
+    name: "linker-unit-tests",
+
+    cflags: [
+        "-g",
+        "-Wall",
+        "-Wextra",
+        "-Wunused",
+        "-Werror",
+    ],
+
+    // We need to access Bionic private headers in the linker.
+    include_dirs: ["bionic/libc"],
+
+    srcs: [
+        // Tests.
+        "linker_block_allocator_test.cpp",
+        "linker_config_test.cpp",
+        "linked_list_test.cpp",
+        "linker_sleb128_test.cpp",
+        "linker_utils_test.cpp",
+
+        // Parts of the linker that we're testing.
+        "linker_block_allocator.cpp",
+        "linker_config.cpp",
+        "linker_test_globals.cpp",
+        "linker_utils.cpp",
+    ],
+
+    static_libs: [
+        "libasync_safe",
+        "libbase",
+        "liblog",
+    ],
+}
diff --git a/linker/Android.mk b/linker/Android.mk
deleted file mode 100644
index ea7451c..0000000
--- a/linker/Android.mk
+++ /dev/null
@@ -1,3 +0,0 @@
-LOCAL_PATH := $(call my-dir)
-
-include $(call first-makefiles-under,$(LOCAL_PATH))
diff --git a/linker/tests/linked_list_test.cpp b/linker/linked_list_test.cpp
similarity index 99%
rename from linker/tests/linked_list_test.cpp
rename to linker/linked_list_test.cpp
index 2b88ed0..71a7d09 100644
--- a/linker/tests/linked_list_test.cpp
+++ b/linker/linked_list_test.cpp
@@ -32,7 +32,7 @@
 
 #include <gtest/gtest.h>
 
-#include "../linked_list.h"
+#include "linked_list.h"
 
 namespace {
 
diff --git a/linker/linker.cpp b/linker/linker.cpp
index ed84a46..8a70ca9 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -2171,9 +2171,13 @@
            new_name);
     // Some APEXs could be optionally disabled. Only translate the path
     // when the old file is absent and the new file exists.
+    // TODO(b/124218500): Re-enable it once app compat issue is resolved
+    /*
     if (file_exists(name)) {
       LD_LOG(kLogDlopen, "dlopen %s exists, not translating", name);
-    } else if (!file_exists(new_name)) {
+    } else
+    */
+    if (!file_exists(new_name)) {
       LD_LOG(kLogDlopen, "dlopen %s does not exist, not translating",
              new_name);
     } else {
diff --git a/linker/tests/linker_block_allocator_test.cpp b/linker/linker_block_allocator_test.cpp
similarity index 98%
rename from linker/tests/linker_block_allocator_test.cpp
rename to linker/linker_block_allocator_test.cpp
index d5eb97c..359eefb 100644
--- a/linker/tests/linker_block_allocator_test.cpp
+++ b/linker/linker_block_allocator_test.cpp
@@ -32,7 +32,7 @@
 
 #include <gtest/gtest.h>
 
-#include "../linker_block_allocator.h"
+#include "linker_block_allocator.h"
 
 #include <unistd.h>
 
@@ -145,4 +145,3 @@
   testing::FLAGS_gtest_death_test_style = "threadsafe";
   ASSERT_EXIT(protect_all(), testing::KilledBySignal(SIGSEGV), "trying to access protected page");
 }
-
diff --git a/linker/tests/linker_config_test.cpp b/linker/linker_config_test.cpp
similarity index 99%
rename from linker/tests/linker_config_test.cpp
rename to linker/linker_config_test.cpp
index 14fd132..6a55bb2 100644
--- a/linker/tests/linker_config_test.cpp
+++ b/linker/linker_config_test.cpp
@@ -32,8 +32,8 @@
 
 #include <gtest/gtest.h>
 
-#include "../linker_config.h"
-#include "../linker_utils.h"
+#include "linker_config.h"
+#include "linker_utils.h"
 
 #include <unistd.h>
 
diff --git a/linker/linker_debug.h b/linker/linker_debug.h
index 862ea12..7a1cb3c 100644
--- a/linker/linker_debug.h
+++ b/linker/linker_debug.h
@@ -56,6 +56,7 @@
 #include <unistd.h>
 
 #include <async_safe/log.h>
+#include <async_safe/CHECK.h>
 
 __LIBC_HIDDEN__ extern int g_ld_debug_verbosity;
 
diff --git a/linker/tests/linker_sleb128_test.cpp b/linker/linker_sleb128_test.cpp
similarity index 98%
rename from linker/tests/linker_sleb128_test.cpp
rename to linker/linker_sleb128_test.cpp
index 551faf2..9e819c6 100644
--- a/linker/tests/linker_sleb128_test.cpp
+++ b/linker/linker_sleb128_test.cpp
@@ -32,7 +32,7 @@
 
 #include <gtest/gtest.h>
 
-#include "../linker_sleb128.h"
+#include "linker_sleb128.h"
 
 TEST(linker_sleb128, smoke) {
   std::vector<uint8_t> encoding;
diff --git a/linker/tests/linker_globals.cpp b/linker/linker_test_globals.cpp
similarity index 100%
rename from linker/tests/linker_globals.cpp
rename to linker/linker_test_globals.cpp
diff --git a/linker/linker_tls.cpp b/linker/linker_tls.cpp
index a3aa9bf..d2edbb3 100644
--- a/linker/linker_tls.cpp
+++ b/linker/linker_tls.cpp
@@ -30,6 +30,7 @@
 
 #include <vector>
 
+#include "async_safe/CHECK.h"
 #include "private/ScopedRWLock.h"
 #include "private/ScopedSignalBlocker.h"
 #include "private/bionic_defs.h"
diff --git a/linker/tests/linker_utils_test.cpp b/linker/linker_utils_test.cpp
similarity index 99%
rename from linker/tests/linker_utils_test.cpp
rename to linker/linker_utils_test.cpp
index e406af5..44907da 100644
--- a/linker/tests/linker_utils_test.cpp
+++ b/linker/linker_utils_test.cpp
@@ -32,7 +32,7 @@
 
 #include <gtest/gtest.h>
 
-#include "../linker_utils.h"
+#include "linker_utils.h"
 
 TEST(linker_utils, format_string) {
   std::vector<std::pair<std::string, std::string>> params = {{ "LIB", "lib32"}, { "SDKVER", "42"}};
diff --git a/linker/tests/Android.mk b/linker/tests/Android.mk
deleted file mode 100644
index 63e0555..0000000
--- a/linker/tests/Android.mk
+++ /dev/null
@@ -1,54 +0,0 @@
-#
-# Copyright (C) 2012 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.
-#
-
-LOCAL_PATH:= $(call my-dir)
-
-include $(CLEAR_VARS)
-LOCAL_MODULE := linker-unit-tests
-LOCAL_MODULE_STEM_32 := $(LOCAL_MODULE)32
-LOCAL_MODULE_STEM_64 := $(LOCAL_MODULE)64
-
-LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
-
-LOCAL_CFLAGS += -g -Wall -Wextra -Wunused -Werror
-LOCAL_C_INCLUDES := $(LOCAL_PATH)/../../libc/
-
-LOCAL_SRC_FILES := \
-  linker_block_allocator_test.cpp \
-  linker_config_test.cpp \
-  linker_globals.cpp \
-  linked_list_test.cpp \
-  linker_sleb128_test.cpp \
-  linker_utils_test.cpp \
-  ../linker_block_allocator.cpp \
-  ../linker_config.cpp \
-  ../linker_utils.cpp \
-
-LOCAL_STATIC_LIBRARIES += libasync_safe libbase liblog
-
-include $(BUILD_NATIVE_TEST)
diff --git a/tests/malloc_iterate_test.cpp b/tests/malloc_iterate_test.cpp
index 5e60a6d..76583eb 100644
--- a/tests/malloc_iterate_test.cpp
+++ b/tests/malloc_iterate_test.cpp
@@ -92,14 +92,15 @@
   test_data->total_allocated_bytes = 0;
 
   // Find all of the maps that are [anon:libc_malloc].
-  ASSERT_TRUE(android::procinfo::ReadMapFile("/proc/self/maps",
-    [&](uint64_t start, uint64_t end, uint16_t, uint64_t, const char* name) {
-    if (std::string(name) == "[anon:libc_malloc]") {
-      malloc_disable();
-      malloc_iterate(start, end - start, SavePointers, test_data);
-      malloc_enable();
-    }
-  }));
+  ASSERT_TRUE(android::procinfo::ReadMapFile(
+      "/proc/self/maps",
+      [&](uint64_t start, uint64_t end, uint16_t, uint64_t, ino_t, const char* name) {
+        if (std::string(name) == "[anon:libc_malloc]") {
+          malloc_disable();
+          malloc_iterate(start, end - start, SavePointers, test_data);
+          malloc_enable();
+        }
+      }));
 
   for (size_t i = 0; i < test_data->allocs.size(); i++) {
     EXPECT_EQ(1UL, test_data->allocs[i].count) << "Failed on size " << test_data->allocs[i].size;
@@ -180,14 +181,15 @@
   TestDataType test_data = {};
 
   // Find all of the maps that are not [anon:libc_malloc].
-  ASSERT_TRUE(android::procinfo::ReadMapFile("/proc/self/maps",
-    [&](uint64_t start, uint64_t end, uint16_t, uint64_t, const char* name) {
-    if (std::string(name) != "[anon:libc_malloc]") {
-      malloc_disable();
-      malloc_iterate(start, end - start, SavePointers, &test_data);
-      malloc_enable();
-    }
-  }));
+  ASSERT_TRUE(android::procinfo::ReadMapFile(
+      "/proc/self/maps",
+      [&](uint64_t start, uint64_t end, uint16_t, uint64_t, ino_t, const char* name) {
+        if (std::string(name) != "[anon:libc_malloc]") {
+          malloc_disable();
+          malloc_iterate(start, end - start, SavePointers, &test_data);
+          malloc_enable();
+        }
+      }));
 
   ASSERT_EQ(0UL, test_data.total_allocated_bytes);
 #else
diff --git a/tools/Android.mk b/tools/Android.mk
deleted file mode 100644
index 4dd66fe..0000000
--- a/tools/Android.mk
+++ /dev/null
@@ -1,19 +0,0 @@
-#
-# Copyright (C) 2015 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.
-#
-
-LOCAL_PATH := $(call my-dir)
-
-include $(call all-subdir-makefiles)