diff --git a/init/bootchart.cpp b/init/bootchart.cpp
index b7db9b6..f46fb09 100644
--- a/init/bootchart.cpp
+++ b/init/bootchart.cpp
@@ -140,6 +140,20 @@
 static void bootchart_thread_main() {
   LOG(INFO) << "Bootcharting started";
 
+  // Unshare the mount namespace of this thread so that the init process itself can switch
+  // the mount namespace later while this thread is still running.
+  // Otherwise, setns() call invoked as part of `enter_default_mount_ns` fails with EINVAL.
+  //
+  // Note that after unshare()'ing the mount namespace from the main thread, this thread won't
+  // receive mount/unmount events from the other mount namespace unless the events are happening
+  // from under a sharable mount.
+  //
+  // The bootchart thread is safe to unshare the mount namespace because it only reads from /proc
+  // and write to /data which are not private mounts.
+  if (unshare(CLONE_NEWNS) == -1) {
+      PLOG(ERROR) << "Cannot create mount namespace";
+      return;
+  }
   // Open log files.
   auto stat_log = fopen_unique("/data/bootchart/proc_stat.log", "we");
   if (!stat_log) return;
diff --git a/libutils/VectorImpl.cpp b/libutils/VectorImpl.cpp
index c97a19b..d951b8b 100644
--- a/libutils/VectorImpl.cpp
+++ b/libutils/VectorImpl.cpp
@@ -279,14 +279,12 @@
 
 ssize_t VectorImpl::removeItemsAt(size_t index, size_t count)
 {
-    ALOG_ASSERT((index+count)<=size(),
-        "[%p] remove: index=%d, count=%d, size=%d",
-               this, (int)index, (int)count, (int)size());
-
-    if ((index+count) > size())
-        return BAD_VALUE;
-   _shrink(index, count);
-   return index;
+    size_t end;
+    LOG_ALWAYS_FATAL_IF(__builtin_add_overflow(index, count, &end), "overflow: index=%zu count=%zu",
+                        index, count);
+    if (end > size()) return BAD_VALUE;
+    _shrink(index, count);
+    return index;
 }
 
 void VectorImpl::finish_vector()
diff --git a/libutils/Vector_test.cpp b/libutils/Vector_test.cpp
index 5336c40..6d90eaa 100644
--- a/libutils/Vector_test.cpp
+++ b/libutils/Vector_test.cpp
@@ -136,4 +136,13 @@
   }
 }
 
+TEST_F(VectorTest, removeItemsAt_overflow) {
+    android::Vector<int> v;
+    for (int i = 0; i < 666; i++) v.add(i);
+
+    ASSERT_DEATH(v.removeItemsAt(SIZE_MAX, 666), "overflow");
+    ASSERT_DEATH(v.removeItemsAt(666, SIZE_MAX), "overflow");
+    ASSERT_DEATH(v.removeItemsAt(SIZE_MAX, SIZE_MAX), "overflow");
+}
+
 } // namespace android