If non-secure world pass to virtual address (allocated by malloc or mmap) and ttbr value, how to find valid physical address in secure-world

First sorry my english writing level. :-)

In non-secure world using android system(linux kernel).

I use big.little core Cortex-A53, Cortex-A57

I was tested to 2case.

previous stage.

     1. Linux allocation memory using(malloc or mmap)

     2. Pass allocated memory and TTBR value to secure-world.

     3. Find mapped physical address in TTB address.

1 case.

     - Using only 1core test (linux set_sched_affinity)

     Result : Find very well 100%. (Valid physical address : 0xXXXXXXXX)

2 case.

     - No use set_sched_affinity

     Result : Some time not found (Invalid physical address : 0x0)

I think Linux no mapping page-table. but i didn't understand why 1case success.

1case testing around 1000times.

If probleam is no mapping, why didn't occured 2case situation.

I guess this probleam related page-table attribute like a shareability(inner shareable, outer shareable?) or cache? or etc.

Question.

     How to fixing this case? or I want to some advice.

thanks!