diff --git a/base/include/android-base/macros.h b/base/include/android-base/macros.h
index 49cc0c9..1748665 100644
--- a/base/include/android-base/macros.h
+++ b/base/include/android-base/macros.h
@@ -170,7 +170,9 @@
 //
 //  In either case this macro has no effect on runtime behavior and performance
 //  of code.
+#ifndef FALLTHROUGH_INTENDED
 #define FALLTHROUGH_INTENDED [[clang::fallthrough]]  // NOLINT
+#endif
 
 // Current ABI string
 #if defined(__arm__)
diff --git a/debuggerd/debuggerd_test.cpp b/debuggerd/debuggerd_test.cpp
index 388facb..bea8b43 100644
--- a/debuggerd/debuggerd_test.cpp
+++ b/debuggerd/debuggerd_test.cpp
@@ -37,6 +37,7 @@
 #include <android-base/macros.h>
 #include <android-base/parseint.h>
 #include <android-base/properties.h>
+#include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <android-base/test_utils.h>
 #include <android-base/unique_fd.h>
@@ -1053,3 +1054,42 @@
   ASSERT_TRUE(android::base::ReadFully(output_fd.get(), outbuf, sizeof(outbuf)));
   ASSERT_STREQ("any", outbuf);
 }
+
+TEST(tombstoned, interceptless_backtrace) {
+  // Generate 50 backtraces, and then check to see that we haven't created 50 new tombstones.
+  auto get_tombstone_timestamps = []() -> std::map<int, time_t> {
+    std::map<int, time_t> result;
+    for (int i = 0; i < 99; ++i) {
+      std::string path = android::base::StringPrintf("/data/tombstones/tombstone_%02d", i);
+      struct stat st;
+      if (stat(path.c_str(), &st) == 0) {
+        result[i] = st.st_mtim.tv_sec;
+      }
+    }
+    return result;
+  };
+
+  auto before = get_tombstone_timestamps();
+  for (int i = 0; i < 50; ++i) {
+    raise_debugger_signal(kDebuggerdNativeBacktrace);
+  }
+  auto after = get_tombstone_timestamps();
+
+  int diff = 0;
+  for (int i = 0; i < 99; ++i) {
+    if (after.count(i) == 0) {
+      continue;
+    }
+    if (before.count(i) == 0) {
+      ++diff;
+      continue;
+    }
+    if (before[i] != after[i]) {
+      ++diff;
+    }
+  }
+
+  // We can't be sure that nothing's crash looping in the background.
+  // This should be good enough, though...
+  ASSERT_LT(diff, 10) << "too many new tombstones; is something crashing in the background?";
+}
diff --git a/debuggerd/tombstoned/tombstoned.cpp b/debuggerd/tombstoned/tombstoned.cpp
index 15ae406..ad92067 100644
--- a/debuggerd/tombstoned/tombstoned.cpp
+++ b/debuggerd/tombstoned/tombstoned.cpp
@@ -212,8 +212,13 @@
   bool intercepted =
       intercept_manager->GetIntercept(crash->crash_pid, crash->crash_type, &output_fd);
   if (!intercepted) {
-    std::tie(crash->crash_tombstone_path, output_fd) = CrashQueue::for_crash(crash)->get_output();
-    crash->crash_tombstone_fd.reset(dup(output_fd.get()));
+    if (crash->crash_type == kDebuggerdNativeBacktrace) {
+      // Don't generate tombstones for native backtrace requests.
+      output_fd.reset(open("/dev/null", O_WRONLY | O_CLOEXEC));
+    } else {
+      std::tie(crash->crash_tombstone_path, output_fd) = CrashQueue::for_crash(crash)->get_output();
+      crash->crash_tombstone_fd.reset(dup(output_fd.get()));
+    }
   }
 
   TombstonedCrashPacket response = {
diff --git a/init/Android.mk b/init/Android.mk
index dc400ad..5554995 100644
--- a/init/Android.mk
+++ b/init/Android.mk
@@ -61,9 +61,9 @@
 # Set up the same mount points on the ramdisk that system-as-root contains.
 LOCAL_POST_INSTALL_CMD := \
     mkdir -p $(TARGET_RAMDISK_OUT)/dev \
-    mkdir -p $(TARGET_RAMDISK_OUT)/mnt \
-    mkdir -p $(TARGET_RAMDISK_OUT)/proc \
-    mkdir -p $(TARGET_RAMDISK_OUT)/sys \
+    $(TARGET_RAMDISK_OUT)/mnt \
+    $(TARGET_RAMDISK_OUT)/proc \
+    $(TARGET_RAMDISK_OUT)/sys \
 
 LOCAL_STATIC_LIBRARIES := \
     libfs_mgr \
diff --git a/liblog/tests/liblog_test.cpp b/liblog/tests/liblog_test.cpp
index a8a9a12..d1f20f4 100644
--- a/liblog/tests/liblog_test.cpp
+++ b/liblog/tests/liblog_test.cpp
@@ -30,6 +30,7 @@
 #include <string>
 
 #include <android-base/file.h>
+#include <android-base/macros.h>
 #include <android-base/stringprintf.h>
 #ifdef __ANDROID__  // includes sys/properties.h which does not exist outside
 #include <cutils/properties.h>
@@ -2516,7 +2517,7 @@
 #endif
         elem.data.string = const_cast<char*>("<unknown>");
         elem.len = strlen(elem.data.string);
-      /* FALLTHRU */
+        FALLTHROUGH_INTENDED;
       case EVENT_TYPE_STRING:
         if (elem.len <= strOutLen) {
           memcpy(strOut, elem.data.string, elem.len);
diff --git a/libpixelflinger/Android.mk b/libpixelflinger/Android.mk
index 14883f4..8c80f6a 100644
--- a/libpixelflinger/Android.mk
+++ b/libpixelflinger/Android.mk
@@ -73,6 +73,7 @@
 LOCAL_CFLAGS := $(PIXELFLINGER_CFLAGS)
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 LOCAL_C_INCLUDES += $(LOCAL_EXPORT_C_INCLUDE_DIRS)
+LOCAL_HEADER_LIBRARIES := libbase_headers
 LOCAL_SHARED_LIBRARIES := libcutils liblog libutils
 
 include $(BUILD_SHARED_LIBRARY)
diff --git a/libpixelflinger/buffer.cpp b/libpixelflinger/buffer.cpp
index dcb95c5..ea9514c 100644
--- a/libpixelflinger/buffer.cpp
+++ b/libpixelflinger/buffer.cpp
@@ -18,6 +18,8 @@
 
 #include <assert.h>
 
+#include <android-base/macros.h>
+
 #include "buffer.h"
 
 namespace android {
@@ -266,8 +268,11 @@
     p = downshift_component(p, b,   hbits, lbits,  f->bh, f->bl, 0, 1, -1);
     p = downshift_component(p, a,   hbits, lbits,  f->ah, f->al, 0, 1, -1);
     switch (f->size) {
-    case 1: p |= p << 8;    // fallthrough
-    case 2: p |= p << 16;
+        case 1:
+            p |= p << 8;
+            FALLTHROUGH_INTENDED;
+        case 2:
+            p |= p << 16;
     }
     return p;
 }
diff --git a/libpixelflinger/codeflinger/blending.cpp b/libpixelflinger/codeflinger/blending.cpp
index a55dfe3..2cbb00f 100644
--- a/libpixelflinger/codeflinger/blending.cpp
+++ b/libpixelflinger/codeflinger/blending.cpp
@@ -23,6 +23,7 @@
 #include <stdlib.h>
 #include <sys/types.h>
 
+#include <android-base/macros.h>
 #include <log/log.h>
 
 #include "GGLAssembler.h"
@@ -301,7 +302,7 @@
                 return;
             }                
         }
-        // fall-through...
+        FALLTHROUGH_INTENDED;
     case GGL_ONE_MINUS_DST_COLOR:
     case GGL_DST_COLOR:
     case GGL_ONE_MINUS_SRC_COLOR:
diff --git a/libsysutils/src/SocketClient.cpp b/libsysutils/src/SocketClient.cpp
index 0625db7..fe2f3d6 100644
--- a/libsysutils/src/SocketClient.cpp
+++ b/libsysutils/src/SocketClient.cpp
@@ -27,6 +27,8 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <android-base/file.h>
+#include <android-base/macros.h>
 #include <log/log.h>
 #include <sysutils/SocketClient.h>
 
@@ -145,7 +147,8 @@
         switch (*arg) {
         case '\\':
         case '"':
-            *(current++) = '\\'; // fallthrough
+            *(current++) = '\\';
+            FALLTHROUGH_INTENDED;
         default:
             *(current++) = *(arg++);
         }
diff --git a/libunwindstack/DwarfCfa.cpp b/libunwindstack/DwarfCfa.cpp
index cd9ef61..0fa1638 100644
--- a/libunwindstack/DwarfCfa.cpp
+++ b/libunwindstack/DwarfCfa.cpp
@@ -21,6 +21,7 @@
 #include <type_traits>
 #include <vector>
 
+#include <android-base/macros.h>
 #include <android-base/stringprintf.h>
 
 #include <unwindstack/DwarfError.h>
@@ -154,13 +155,15 @@
       break;
     case DwarfCfaInfo::DWARF_DISPLAY_ADVANCE_LOC:
       *cur_pc += value;
-    // Fall through to log the value.
+      FALLTHROUGH_INTENDED;
+      // Fall through to log the value.
     case DwarfCfaInfo::DWARF_DISPLAY_NUMBER:
       string += " " + std::to_string(value);
       break;
     case DwarfCfaInfo::DWARF_DISPLAY_SET_LOC:
       *cur_pc = value;
-    // Fall through to log the value.
+      FALLTHROUGH_INTENDED;
+      // Fall through to log the value.
     case DwarfCfaInfo::DWARF_DISPLAY_ADDRESS:
       if (std::is_same<AddressType, uint32_t>::value) {
         string += android::base::StringPrintf(" 0x%" PRIx32, static_cast<uint32_t>(value));
diff --git a/libutils/Android.bp b/libutils/Android.bp
index 1c1bdf7..600c91c 100644
--- a/libutils/Android.bp
+++ b/libutils/Android.bp
@@ -59,6 +59,7 @@
         "-Werror",
     ],
     header_libs: [
+        "libbase_headers",
         "libutils_headers",
     ],
     export_header_lib_headers: [
diff --git a/libutils/RefBase.cpp b/libutils/RefBase.cpp
index 3f1e79a..ae10789 100644
--- a/libutils/RefBase.cpp
+++ b/libutils/RefBase.cpp
@@ -19,6 +19,8 @@
 
 #include <memory>
 
+#include <android-base/macros.h>
+
 #include <utils/RefBase.h>
 
 #include <utils/CallStack.h>
@@ -479,7 +481,7 @@
     case INITIAL_STRONG_VALUE:
         refs->mStrong.fetch_sub(INITIAL_STRONG_VALUE,
                 std::memory_order_relaxed);
-        // fall through...
+        FALLTHROUGH_INTENDED;
     case 0:
         refs->mBase->onFirstRef();
     }
diff --git a/libutils/Unicode.cpp b/libutils/Unicode.cpp
index 82f650d..5f0a51f 100644
--- a/libutils/Unicode.cpp
+++ b/libutils/Unicode.cpp
@@ -16,8 +16,9 @@
 
 #define LOG_TAG "unicode"
 
-#include <utils/Unicode.h>
+#include <android-base/macros.h>
 #include <limits.h>
+#include <utils/Unicode.h>
 
 #include <log/log.h>
 
@@ -105,8 +106,11 @@
     switch (bytes)
     {   /* note: everything falls through. */
         case 4: *--dstP = (uint8_t)((srcChar | kByteMark) & kByteMask); srcChar >>= 6;
+            FALLTHROUGH_INTENDED;
         case 3: *--dstP = (uint8_t)((srcChar | kByteMark) & kByteMask); srcChar >>= 6;
+            FALLTHROUGH_INTENDED;
         case 2: *--dstP = (uint8_t)((srcChar | kByteMark) & kByteMask); srcChar >>= 6;
+            FALLTHROUGH_INTENDED;
         case 1: *--dstP = (uint8_t)(srcChar | kFirstByteMark[bytes]);
     }
 }
diff --git a/logcat/logcat.cpp b/logcat/logcat.cpp
index 0f1badb..115b1a3 100644
--- a/logcat/logcat.cpp
+++ b/logcat/logcat.cpp
@@ -16,6 +16,7 @@
 
 #include "logcat.h"
 
+#include <android-base/macros.h>
 #include <arpa/inet.h>
 #include <assert.h>
 #include <ctype.h>
@@ -959,7 +960,7 @@
             case 't':
                 got_t = true;
                 mode |= ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK;
-            // FALLTHRU
+                FALLTHROUGH_INTENDED;
             case 'T':
                 if (strspn(optarg, "0123456789") != strlen(optarg)) {
                     char* cp = parseTime(tail_time, optarg);
@@ -1009,7 +1010,7 @@
                     getLogSize = true;
                     break;
                 }
-            // FALLTHRU
+                FALLTHROUGH_INTENDED;
 
             case 'G': {
                 char* cp;
@@ -1023,15 +1024,15 @@
                     case 'g':
                     case 'G':
                         setLogSize *= 1024;
-                    // FALLTHRU
+                        FALLTHROUGH_INTENDED;
                     case 'm':
                     case 'M':
                         setLogSize *= 1024;
-                    // FALLTHRU
+                        FALLTHROUGH_INTENDED;
                     case 'k':
                     case 'K':
                         setLogSize *= 1024;
-                    // FALLTHRU
+                        FALLTHROUGH_INTENDED;
                     case '\0':
                         break;
 
@@ -1051,7 +1052,7 @@
                     getPruneList = true;
                     break;
                 }
-            // FALLTHRU
+                FALLTHROUGH_INTENDED;
 
             case 'P':
                 setPruneList = optarg;
diff --git a/logcat/tests/logcat_test.cpp b/logcat/tests/logcat_test.cpp
index bebcc71..9483bb2 100644
--- a/logcat/tests/logcat_test.cpp
+++ b/logcat/tests/logcat_test.cpp
@@ -31,6 +31,7 @@
 #include <string>
 
 #include <android-base/file.h>
+#include <android-base/macros.h>
 #include <android-base/stringprintf.h>
 #include <gtest/gtest.h>
 #include <log/event_tag_map.h>
@@ -572,13 +573,13 @@
         switch (size_mult[0]) {
             case 'G':
                 full_size *= 1024;
-            /* FALLTHRU */
+                FALLTHROUGH_INTENDED;
             case 'M':
                 full_size *= 1024;
-            /* FALLTHRU */
+                FALLTHROUGH_INTENDED;
             case 'K':
                 full_size *= 1024;
-            /* FALLTHRU */
+                FALLTHROUGH_INTENDED;
             case 'B':
                 break;
             default:
@@ -588,13 +589,13 @@
         switch (consumed_mult[0]) {
             case 'G':
                 full_consumed *= 1024;
-            /* FALLTHRU */
+                FALLTHROUGH_INTENDED;
             case 'M':
                 full_consumed *= 1024;
-            /* FALLTHRU */
+                FALLTHROUGH_INTENDED;
             case 'K':
                 full_consumed *= 1024;
-            /* FALLTHRU */
+                FALLTHROUGH_INTENDED;
             case 'B':
                 break;
             default:
@@ -1241,26 +1242,26 @@
             switch (size_mult[0]) {
                 case 'G':
                     full_size *= 1024;
-                /* FALLTHRU */
+                    FALLTHROUGH_INTENDED;
                 case 'M':
                     full_size *= 1024;
-                /* FALLTHRU */
+                    FALLTHROUGH_INTENDED;
                 case 'K':
                     full_size *= 1024;
-                /* FALLTHRU */
+                    FALLTHROUGH_INTENDED;
                 case 'B':
                     break;
             }
             switch (consumed_mult[0]) {
                 case 'G':
                     full_consumed *= 1024;
-                /* FALLTHRU */
+                    FALLTHROUGH_INTENDED;
                 case 'M':
                     full_consumed *= 1024;
-                /* FALLTHRU */
+                    FALLTHROUGH_INTENDED;
                 case 'K':
                     full_consumed *= 1024;
-                /* FALLTHRU */
+                    FALLTHROUGH_INTENDED;
                 case 'B':
                     break;
             }
diff --git a/logd/LogKlog.cpp b/logd/LogKlog.cpp
index e4393a3..513c0c3 100644
--- a/logd/LogKlog.cpp
+++ b/logd/LogKlog.cpp
@@ -475,9 +475,7 @@
 static int convertKernelPrioToAndroidPrio(int pri) {
     switch (pri & LOG_PRIMASK) {
         case LOG_EMERG:
-        // FALLTHRU
         case LOG_ALERT:
-        // FALLTHRU
         case LOG_CRIT:
             return ANDROID_LOG_FATAL;
 
@@ -488,9 +486,7 @@
             return ANDROID_LOG_WARN;
 
         default:
-        // FALLTHRU
         case LOG_NOTICE:
-        // FALLTHRU
         case LOG_INFO:
             break;
 
diff --git a/rootdir/etc/public.libraries.android.txt b/rootdir/etc/public.libraries.android.txt
index e20b95d..d8f6095 100644
--- a/rootdir/etc/public.libraries.android.txt
+++ b/rootdir/etc/public.libraries.android.txt
@@ -1,6 +1,7 @@
 # See https://android.googlesource.com/platform/ndk/+/master/docs/PlatformApis.md
 libandroid.so
 libaaudio.so
+libbinder_ndk.so
 libc.so
 libcamera2ndk.so
 libdl.so
diff --git a/rootdir/etc/public.libraries.iot.txt b/rootdir/etc/public.libraries.iot.txt
index ff0813d..20905bf 100644
--- a/rootdir/etc/public.libraries.iot.txt
+++ b/rootdir/etc/public.libraries.iot.txt
@@ -2,6 +2,7 @@
 libandroid.so
 libandroidthings.so
 libaaudio.so
+libbinder_ndk.so
 libc.so
 libcamera2ndk.so
 libdl.so
diff --git a/rootdir/etc/public.libraries.wear.txt b/rootdir/etc/public.libraries.wear.txt
index 3c46094..4ece5b5 100644
--- a/rootdir/etc/public.libraries.wear.txt
+++ b/rootdir/etc/public.libraries.wear.txt
@@ -1,6 +1,7 @@
 # See https://android.googlesource.com/platform/ndk/+/master/docs/PlatformApis.md
 libandroid.so
 libaaudio.so
+libbinder_ndk.so
 libc.so
 libcamera2ndk.so
 libdl.so