[Honor 6, 6 Plus General] IcedLance:
And is there any reliable way to unroot completely and utterly?

I did a 3-button update (after unrooting KingRoot) and got a few OTA after that, but I still can't relock it (never really tried before update).

So the whole story is (someone might find it useful):

After rooting with KingRoot (the most reliable way according to many people) on B108SP01 I made backups with TB (what I needed root for) and decided to play a bit with system properties, except... /system was mounted in RO and seemed to be locked in that state. Attempts to remount it were returning the "Read-only file system" error (yeah, the "mount -o rw,remount ..." thingie itself). Well ,no biggie, thought I at that time, I have root now, i'll just install Busybox and everything wil be peachy. Like if. Busybox failed to install. Figures, /system was RO after all.

So I did some reading and tried all kinds of terminal emulators, command attribute sets, some file managers with remounting options, and it seemed to start cracking bit by bit.

At first it suddenly agreed to remount to RW, but popped back into RO after i tried to create a file in /system. Then it held for a little longer and even allowed me to make a change in build.prop (which didn't affect system behaviour as it should have and reverted after reboot). At that point I was desperate and the device caving in for the first time made me reckless. I started experimenting with "su" command itself. Stupid though, but it worked. [I figured KingRoot was protecting itself by giving away some kind of weakened root to everyone else, stupid, but i ran out of smarter ideas by then.] So I went and punched into the terminal the "su 1" command. Much to my shame I failed the basic tech-ed test and decided the 1st user would be the best user. While I was contemplating my life decisions terminal hiccuped, and... swallowed that command with no comments.

And that was Victory!

AFter that /system remounted successfully into RW and Busybox popped in and even script meant to replace KR with SS worked. Now SS was the master of my system and since it was a very reputable root app I though highly of it. Shouldn't have. First reboot and it's all back. S disappeared, KR rules the dancefloor. Or more like what's left of the dancefloor. Nothing I tried since ever worked. Mount was now returning OK if i tried to remount smth RO, and "Invalid argument on RW". The mighty "su 1" that has slayed the beast the first time was now working as intended and returning gibberish. And that was the end of it.

After making a final round of backups I unrooted through that same KingRoot and did 3-button update to B109SP01.

It went smoothly, recieved a couple OTA to B394, and I started reading about ways to root it (and partially about the problems I encountered with KingRoot.

And then I found a post stating that KingRoot seems to do an incomplete unlock, and so i went and checked it.

"fastboot oem get-bootinfo" - unlocked

"fastboot oem unlock ***" - stalled for a few sec and returned 'Unlocked'

"fastboot oem relock" - (remote: root type is risk)

I'm gonna get root properly now and look into it more, but if you have any tips/experience to share, I'm all ears (eyes actually, beholder-style:cyclops:).