diff --git a/libc/Android.bp b/libc/Android.bp
index 84b4b12..147c2bb 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -47,6 +47,9 @@
     // Clang's exit-time destructor registration hides __dso_handle, but
     // __dso_handle needs to have default visibility on ARM32. See b/73485611.
     "-Wexit-time-destructors",
+
+    // GWP-ASan requires platform TLS.
+    "-fno-emulated-tls",
 ]
 
 // Define some common cflags
@@ -62,6 +65,8 @@
         "bionic/libc/async_safe/include",
     ],
 
+    header_libs: ["gwp_asan_headers"],
+
     stl: "none",
     system_shared_libs: [],
     sanitize: {
@@ -111,6 +116,7 @@
         "libjemalloc5",
         "libc_jemalloc_wrapper",
     ],
+    header_libs: ["gwp_asan_headers"],
 }
 
 // Functions not implemented by jemalloc directly, or that need to
@@ -1391,6 +1397,7 @@
     ],
     ramdisk_available: false,
     srcs: libc_common_src_files + [
+        "bionic/gwp_asan_wrappers.cpp",
         "bionic/heap_tagging.cpp",
         "bionic/malloc_common.cpp",
         "bionic/malloc_limit.cpp",
@@ -1418,6 +1425,7 @@
     ],
 
     whole_static_libs: [
+        "gwp_asan",
         "libc_bionic_ndk",
         "libc_bootstrap",
         "libc_fortify",
@@ -1597,6 +1605,7 @@
     srcs: [
         "arch-common/bionic/crtbegin_so.c",
         "arch-common/bionic/crtbrand.S",
+        "bionic/gwp_asan_wrappers.cpp",
         "bionic/heap_tagging.cpp",
         "bionic/icu.cpp",
         "bionic/malloc_common.cpp",
@@ -1614,6 +1623,7 @@
 filegroup {
     name: "libc_sources_static",
     srcs: [
+        "bionic/gwp_asan_wrappers.cpp",
         "bionic/heap_tagging.cpp",
         "bionic/malloc_common.cpp",
         "bionic/malloc_limit.cpp",
@@ -1648,6 +1658,7 @@
         srcs: [ ":libc_sources_static" ],
         cflags: ["-DLIBC_STATIC"],
         whole_static_libs: [
+            "gwp_asan",
             "libc_init_static",
             "libc_common_static",
             "libc_unwind_static",
@@ -1656,6 +1667,7 @@
     shared: {
         srcs: [ ":libc_sources_shared" ],
         whole_static_libs: [
+            "gwp_asan",
             "libc_init_dynamic",
             "libc_common_shared",
         ],
@@ -2504,6 +2516,7 @@
 cc_defaults {
     name: "libc_scudo_wrapper_defaults",
     srcs: [
+        "bionic/gwp_asan_wrappers.cpp",
         "bionic/heap_tagging.cpp",
         "bionic/malloc_common.cpp",
         "bionic/malloc_common_dynamic.cpp",
@@ -2512,12 +2525,21 @@
         "bionic/scudo_wrapper.cpp",
         "bionic/__set_errno.cpp",
     ],
-    cflags: ["-DUSE_SCUDO"],
+    cflags: [
+        "-DUSE_SCUDO",
+        "-fno-emulated-tls", // Required for GWP-ASan.
+    ],
     shared_libs: ["libscudo_wrapper"],
 
-    header_libs: ["libc_headers"],
+    header_libs: [
+        "libc_headers",
+        "gwp_asan_headers",
+    ],
 
-    static_libs: ["libasync_safe"],
+    static_libs: [
+        "libasync_safe",
+        "gwp_asan",
+    ],
 
     arch: {
         arm: {
diff --git a/libc/bionic/gwp_asan_wrappers.cpp b/libc/bionic/gwp_asan_wrappers.cpp
new file mode 100644
index 0000000..680c5e7
--- /dev/null
+++ b/libc/bionic/gwp_asan_wrappers.cpp
@@ -0,0 +1,263 @@
+/*
+ * Copyright (C) 2020 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 <platform/bionic/malloc.h>
+#include <private/bionic_malloc_dispatch.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include "bionic/gwp_asan_wrappers.h"
+#include "gwp_asan/guarded_pool_allocator.h"
+#include "gwp_asan/options.h"
+#include "gwp_asan/random.h"
+#include "malloc_common.h"
+
+#ifndef LIBC_STATIC
+#include "bionic/malloc_common_dynamic.h"
+#endif  // LIBC_STATIC
+
+static gwp_asan::GuardedPoolAllocator GuardedAlloc;
+static const MallocDispatch* prev_dispatch;
+
+using Options = gwp_asan::options::Options;
+
+// ============================================================================
+// Implementation of gFunctions.
+// ============================================================================
+
+// This function handles initialisation as asked for by MallocInitImpl. This
+// should always be called in a single-threaded context.
+bool gwp_asan_initialize(const MallocDispatch* dispatch, bool*, const char*) {
+  prev_dispatch = dispatch;
+
+  Options Opts;
+  Opts.Enabled = true;
+  Opts.MaxSimultaneousAllocations = 32;
+  Opts.SampleRate = 2500;
+  Opts.InstallSignalHandlers = false;
+  Opts.InstallForkHandlers = true;
+
+  GuardedAlloc.init(Opts);
+  info_log("GWP-ASan has been enabled.");
+  return true;
+}
+
+void gwp_asan_finalize() {
+}
+
+void gwp_asan_get_malloc_leak_info(uint8_t**, size_t*, size_t*, size_t*, size_t*) {
+}
+
+void gwp_asan_free_malloc_leak_info(uint8_t*) {
+}
+
+ssize_t gwp_asan_malloc_backtrace(void*, uintptr_t*, size_t) {
+  // TODO(mitchp): GWP-ASan might be able to return the backtrace for the
+  // provided address.
+  return -1;
+}
+
+bool gwp_asan_write_malloc_leak_info(FILE*) {
+  return false;
+}
+
+void* gwp_asan_gfunctions[] = {
+  (void*)gwp_asan_initialize,           (void*)gwp_asan_finalize,
+  (void*)gwp_asan_get_malloc_leak_info, (void*)gwp_asan_free_malloc_leak_info,
+  (void*)gwp_asan_malloc_backtrace,     (void*)gwp_asan_write_malloc_leak_info,
+};
+
+// ============================================================================
+// Implementation of GWP-ASan malloc wrappers.
+// ============================================================================
+
+void* gwp_asan_calloc(size_t n_elements, size_t elem_size) {
+  if (__predict_false(GuardedAlloc.shouldSample())) {
+    size_t bytes;
+    if (!__builtin_mul_overflow(n_elements, elem_size, &bytes)) {
+      if (void* result = GuardedAlloc.allocate(bytes)) {
+        return result;
+      }
+    }
+  }
+  return prev_dispatch->calloc(n_elements, elem_size);
+}
+
+void gwp_asan_free(void* mem) {
+  if (__predict_false(GuardedAlloc.pointerIsMine(mem))) {
+    GuardedAlloc.deallocate(mem);
+    return;
+  }
+  prev_dispatch->free(mem);
+}
+
+void* gwp_asan_malloc(size_t bytes) {
+  if (__predict_false(GuardedAlloc.shouldSample())) {
+    if (void* result = GuardedAlloc.allocate(bytes)) {
+      return result;
+    }
+  }
+  return prev_dispatch->malloc(bytes);
+}
+
+size_t gwp_asan_malloc_usable_size(const void* mem) {
+  if (__predict_false(GuardedAlloc.pointerIsMine(mem))) {
+    return GuardedAlloc.getSize(mem);
+  }
+  return prev_dispatch->malloc_usable_size(mem);
+}
+
+void* gwp_asan_realloc(void* old_mem, size_t bytes) {
+  if (__predict_false(GuardedAlloc.pointerIsMine(old_mem))) {
+    size_t old_size = GuardedAlloc.getSize(old_mem);
+    void* new_ptr = gwp_asan_malloc(bytes);
+    if (new_ptr) memcpy(new_ptr, old_mem, (bytes < old_size) ? bytes : old_size);
+    GuardedAlloc.deallocate(old_mem);
+    return new_ptr;
+  }
+  return prev_dispatch->realloc(old_mem, bytes);
+}
+
+int gwp_asan_malloc_iterate(uintptr_t base, size_t size,
+                            void (*callback)(uintptr_t base, size_t size, void* arg), void* arg) {
+  if (__predict_false(GuardedAlloc.pointerIsMine(reinterpret_cast<void*>(base)))) {
+    // TODO(mitchp): GPA::iterate() returns void, but should return int.
+    // TODO(mitchp): GPA::iterate() should take uintptr_t, not void*.
+    GuardedAlloc.iterate(reinterpret_cast<void*>(base), size, callback, arg);
+    return 0;
+  }
+  return prev_dispatch->malloc_iterate(base, size, callback, arg);
+}
+
+void gwp_asan_malloc_disable() {
+  GuardedAlloc.disable();
+  prev_dispatch->malloc_disable();
+}
+
+void gwp_asan_malloc_enable() {
+  GuardedAlloc.enable();
+  prev_dispatch->malloc_enable();
+}
+
+static const MallocDispatch gwp_asan_dispatch __attribute__((unused)) = {
+  gwp_asan_calloc,
+  gwp_asan_free,
+  Malloc(mallinfo),
+  gwp_asan_malloc,
+  gwp_asan_malloc_usable_size,
+  Malloc(memalign),
+  Malloc(posix_memalign),
+#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
+  Malloc(pvalloc),
+#endif
+  gwp_asan_realloc,
+#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
+  Malloc(valloc),
+#endif
+  gwp_asan_malloc_iterate,
+  gwp_asan_malloc_disable,
+  gwp_asan_malloc_enable,
+  Malloc(mallopt),
+  Malloc(aligned_alloc),
+  Malloc(malloc_info),
+};
+
+// TODO(mitchp): Turn on GWP-ASan here probabilistically.
+bool ShouldGwpAsanSampleProcess() {
+  return false;
+}
+
+bool MaybeInitGwpAsanFromLibc() {
+  // Never initialize the Zygote here. A Zygote chosen for sampling would also
+  // have all of its children sampled. Instead, the Zygote child will choose
+  // whether it samples or not just after the Zygote forks. For
+  // libc_scudo-preloaded executables (like mediaswcodec), the program name
+  // might not be available yet. The zygote never uses dynamic libc_scudo.
+  const char* progname = getprogname();
+  if (progname && strncmp(progname, "app_process", 11) == 0) {
+    return false;
+  }
+  return MaybeInitGwpAsan(false);
+}
+
+static bool GwpAsanInitialized = false;
+
+// Maybe initializes GWP-ASan. Called by android_mallopt() and libc's
+// initialisation. This should always be called in a single-threaded context.
+bool MaybeInitGwpAsan(bool force_init) {
+  if (GwpAsanInitialized) {
+    error_log("GWP-ASan was already initialized for this process.");
+    return false;
+  }
+
+  // If the caller hasn't forced GWP-ASan on, check whether we should sample
+  // this process.
+  if (!force_init && !ShouldGwpAsanSampleProcess()) {
+    return false;
+  }
+
+  // GWP-ASan is compatible with heapprofd/malloc_debug/malloc_hooks iff
+  // GWP-ASan was installed first. If one of these other libraries was already
+  // installed, we don't enable GWP-ASan. These libraries are normally enabled
+  // in libc_init after GWP-ASan, but if the new process is a zygote child and
+  // trying to initialize GWP-ASan through mallopt(), one of these libraries may
+  // be installed. It may be possible to change this in future by modifying the
+  // internal dispatch pointers of these libraries at this point in time, but
+  // given that they're all debug-only, we don't really mind for now.
+  if (GetDefaultDispatchTable() != nullptr) {
+    // Something else is installed.
+    return false;
+  }
+
+  // GWP-ASan's initialization is always called in a single-threaded context, so
+  // we can initialize lock-free.
+  __libc_globals.mutate([](libc_globals* globals) {
+    // Set GWP-ASan as the malloc dispatch table.
+    globals->malloc_dispatch_table = gwp_asan_dispatch;
+    atomic_store(&globals->default_dispatch_table, &gwp_asan_dispatch);
+
+    // If malloc_limit isn't installed, we can skip the default_dispatch_table
+    // lookup.
+    if (GetDispatchTable() == nullptr) {
+      atomic_store(&globals->current_dispatch_table, &gwp_asan_dispatch);
+    }
+  });
+
+#ifndef LIBC_STATIC
+  SetGlobalFunctions(gwp_asan_gfunctions);
+#endif  // LIBC_STATIC
+
+  GwpAsanInitialized = true;
+
+  gwp_asan_initialize(NativeAllocatorDispatch(), nullptr, nullptr);
+
+  return true;
+}
diff --git a/libc/bionic/gwp_asan_wrappers.h b/libc/bionic/gwp_asan_wrappers.h
new file mode 100644
index 0000000..9bbc593
--- /dev/null
+++ b/libc/bionic/gwp_asan_wrappers.h
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2020 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.
+ */
+
+#pragma once
+
+#include <stddef.h>
+#include <private/bionic_malloc_dispatch.h>
+
+// Hooks for libc to possibly install GWP-ASan.
+bool MaybeInitGwpAsanFromLibc();
+
+// Maybe initialize GWP-ASan. Set force_init to true to bypass process sampling.
+bool MaybeInitGwpAsan(bool force_init = false);
diff --git a/libc/bionic/malloc_common.cpp b/libc/bionic/malloc_common.cpp
index e08083f..da68c80 100644
--- a/libc/bionic/malloc_common.cpp
+++ b/libc/bionic/malloc_common.cpp
@@ -41,6 +41,7 @@
 #include <private/bionic_config.h>
 #include <platform/bionic/malloc.h>
 
+#include "gwp_asan_wrappers.h"
 #include "heap_tagging.h"
 #include "malloc_common.h"
 #include "malloc_limit.h"
@@ -316,8 +317,42 @@
   if (opcode == M_SET_HEAP_TAGGING_LEVEL) {
     return SetHeapTaggingLevel(arg, arg_size);
   }
+  if (opcode == M_INITIALIZE_GWP_ASAN) {
+    if (arg == nullptr || arg_size != sizeof(bool)) {
+      errno = EINVAL;
+      return false;
+    }
+    return MaybeInitGwpAsan(*reinterpret_cast<bool*>(arg));
+  }
   errno = ENOTSUP;
   return false;
 }
 #endif
 // =============================================================================
+
+static constexpr MallocDispatch __libc_malloc_default_dispatch __attribute__((unused)) = {
+  Malloc(calloc),
+  Malloc(free),
+  Malloc(mallinfo),
+  Malloc(malloc),
+  Malloc(malloc_usable_size),
+  Malloc(memalign),
+  Malloc(posix_memalign),
+#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
+  Malloc(pvalloc),
+#endif
+  Malloc(realloc),
+#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
+  Malloc(valloc),
+#endif
+  Malloc(malloc_iterate),
+  Malloc(malloc_disable),
+  Malloc(malloc_enable),
+  Malloc(mallopt),
+  Malloc(aligned_alloc),
+  Malloc(malloc_info),
+};
+
+const MallocDispatch* NativeAllocatorDispatch() {
+  return &__libc_malloc_default_dispatch;
+}
diff --git a/libc/bionic/malloc_common.h b/libc/bionic/malloc_common.h
index 79bf98c..4afcc4a 100644
--- a/libc/bionic/malloc_common.h
+++ b/libc/bionic/malloc_common.h
@@ -74,6 +74,8 @@
 
 #endif
 
+const MallocDispatch* NativeAllocatorDispatch();
+
 static inline const MallocDispatch* GetDispatchTable() {
   return atomic_load_explicit(&__libc_globals->current_dispatch_table, memory_order_acquire);
 }
diff --git a/libc/bionic/malloc_common_dynamic.cpp b/libc/bionic/malloc_common_dynamic.cpp
index 2cb1e8a..79d2521 100644
--- a/libc/bionic/malloc_common_dynamic.cpp
+++ b/libc/bionic/malloc_common_dynamic.cpp
@@ -64,6 +64,7 @@
 
 #include <sys/system_properties.h>
 
+#include "gwp_asan_wrappers.h"
 #include "heap_tagging.h"
 #include "malloc_common.h"
 #include "malloc_common_dynamic.h"
@@ -90,30 +91,6 @@
 
 // =============================================================================
 
-static constexpr MallocDispatch __libc_malloc_default_dispatch
-  __attribute__((unused)) = {
-    Malloc(calloc),
-    Malloc(free),
-    Malloc(mallinfo),
-    Malloc(malloc),
-    Malloc(malloc_usable_size),
-    Malloc(memalign),
-    Malloc(posix_memalign),
-#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
-    Malloc(pvalloc),
-#endif
-    Malloc(realloc),
-#if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
-    Malloc(valloc),
-#endif
-    Malloc(malloc_iterate),
-    Malloc(malloc_disable),
-    Malloc(malloc_enable),
-    Malloc(mallopt),
-    Malloc(aligned_alloc),
-    Malloc(malloc_info),
-  };
-
 static constexpr char kHooksSharedLib[] = "libc_malloc_hooks.so";
 static constexpr char kHooksPrefix[] = "hooks";
 static constexpr char kHooksPropertyEnable[] = "libc.debug.hooks.enable";
@@ -261,6 +238,12 @@
   return true;
 }
 
+void SetGlobalFunctions(void* functions[]) {
+  for (size_t i = 0; i < FUNC_LAST; i++) {
+    gFunctions[i] = functions[i];
+  }
+}
+
 static void ClearGlobalFunctions() {
   for (size_t i = 0; i < FUNC_LAST; i++) {
     gFunctions[i] = nullptr;
@@ -344,7 +327,15 @@
 
 bool FinishInstallHooks(libc_globals* globals, const char* options, const char* prefix) {
   init_func_t init_func = reinterpret_cast<init_func_t>(gFunctions[FUNC_INITIALIZE]);
-  if (!init_func(&__libc_malloc_default_dispatch, &gZygoteChild, options)) {
+
+  // If GWP-ASan was initialised, we should use it as the dispatch table for
+  // heapprofd/malloc_debug/malloc_debug.
+  const MallocDispatch* prev_dispatch = GetDefaultDispatchTable();
+  if (prev_dispatch == nullptr) {
+    prev_dispatch = NativeAllocatorDispatch();
+  }
+
+  if (!init_func(prev_dispatch, &gZygoteChild, options)) {
     error_log("%s: failed to enable malloc %s", getprogname(), prefix);
     ClearGlobalFunctions();
     return false;
@@ -388,6 +379,8 @@
   char prop[PROP_VALUE_MAX];
   char* options = prop;
 
+  MaybeInitGwpAsanFromLibc();
+
   // Prefer malloc debug since it existed first and is a more complete
   // malloc interceptor than the hooks.
   bool hook_installed = false;
@@ -531,6 +524,13 @@
   if (opcode == M_SET_HEAP_TAGGING_LEVEL) {
     return SetHeapTaggingLevel(arg, arg_size);
   }
+  if (opcode == M_INITIALIZE_GWP_ASAN) {
+    if (arg == nullptr || arg_size != sizeof(bool)) {
+      errno = EINVAL;
+      return false;
+    }
+    return MaybeInitGwpAsan(*reinterpret_cast<bool*>(arg));
+  }
   // Try heapprofd's mallopt, as it handles options not covered here.
   return HeapprofdMallopt(opcode, arg, arg_size);
 }
diff --git a/libc/bionic/malloc_common_dynamic.h b/libc/bionic/malloc_common_dynamic.h
index 755af8f..048d42a 100644
--- a/libc/bionic/malloc_common_dynamic.h
+++ b/libc/bionic/malloc_common_dynamic.h
@@ -45,3 +45,6 @@
 // Lock for globals, to guarantee that only one thread is doing a mutate.
 extern pthread_mutex_t gGlobalsMutateLock;
 extern _Atomic bool gGlobalsMutating;
+
+// Function hooks instantiations, used by dispatch-table allocators to install themselves.
+void SetGlobalFunctions(void* functions[]);
diff --git a/libc/platform/bionic/malloc.h b/libc/platform/bionic/malloc.h
index 27d79ff..99eefa4 100644
--- a/libc/platform/bionic/malloc.h
+++ b/libc/platform/bionic/malloc.h
@@ -97,6 +97,14 @@
   //   arg_size = sizeof(bool)
   M_GET_PROCESS_PROFILEABLE = 9,
 #define M_GET_PROCESS_PROFILEABLE M_GET_PROCESS_PROFILEABLE
+  // Maybe enable GWP-ASan. Set *arg to force GWP-ASan to be turned on,
+  // otherwise this mallopt() will internally decide whether to sample the
+  // process. The program must be single threaded at the point when the
+  // android_mallopt function is called.
+  //   arg = bool*
+  //   arg_size = sizeof(bool)
+  M_INITIALIZE_GWP_ASAN = 10,
+#define M_INITIALIZE_GWP_ASAN M_INITIALIZE_GWP_ASAN
 };
 
 enum HeapTaggingLevel {