How to adb remount for the latest AOSP on db845c?

Products Support DragonBoard 845c
#1 
adb root
adb remount
failed to remount partition dev:/dev/block/dm-0 mnt:/: Permission denied
failed to remount partition dev:/dev/block/dm-1 mnt:/vendor: Permission denied
failed to remount partition dev:/dev/block/dm-2 mnt:/system_ext: Permission denied
failed to remount partition dev:/dev/block/dm-3 mnt:/product: Permission denied
remount failed

In the latest AOSP(androidT) for db845c, I tried the adb remount cmd, it told me above errors.
I also tried mount -o rw,remount /dev/block/platform/soc@0/1d84000.ufshc/by-name/vendor still failed.

So what should I do to remount vendor partition?
I wanted to push my .so or some files for verification.
Currently I have to compile super.img and flash it, which cost my much time.

Thanks.

#2

I found one solution:

mkdir /cache/tmpfs
mount -t tmpfs tmpfs_name /cache/tmpfs
mkdir /cache/tmpfs/upper
mkdir /cache/tmpfs/work
mount -t overlay overlay_name -o lowerdir=/vendor,upperdir=/cache/tmpfs/upper,workdir=/cache/tmpfs/work /vendor

Then I can push files into /vendor.