[Question] mprotect() can't clear PROT_MTE

[Yang Shi]

Hi Catalin,

Our customers have usecase to untag memory w/o unmapping it, but 
mprotect can't do it. It seems like an intended behavior because I saw 
MTE doc explicitly says PROT_MTE flags can't be cleared by mprotect().
But I don't see why mprotect() can't do it if I don't miss anything. So 
I'd like to know why it behaves in this way.

unmap + mmap or mmap(MAP_FIXED) can do the trick, but it is not feasible 
for anonymous mapping because unamp will wipe all the data.

Thanks,
Yang