get_tls_block_ptr
libc_free_aligned(get_tls_block_ptr(tcb, tcbsize));
memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize),
memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize),
free(get_tls_block_ptr(oldtcb, tcbsize));
free(get_tls_block_ptr(tcb, tcbsize));