We need to backport the following to correct alignment of TLS variables.

commit bc79db3fd487daea36e7c130f943cfb9826a41b4
Author: Stefan Liebler <stli.com>
Date:   Wed Feb 6 09:06:34 2019 +0100

    Fix alignment of TLS variables for tls variant TLS_TCB_AT_TP [BZ #23403]
    
    The alignment of TLS variables is wrong if accessed from within a thread
    for architectures with tls variant TLS_TCB_AT_TP.
    For the main thread the static tls data is properly aligned.
    For other threads the alignment depends on the alignment of the thread
    pointer as the static tls data is located relative to this pointer.
    
    This patch adds this alignment for TLS_TCB_AT_TP variants in the same way
    as it is already done for TLS_DTV_AT_TP. The thread pointer is also already
    properly aligned if the user provides its own stack for the new thread.
    
    This patch extends the testcase nptl/tst-tls1.c in order to check the
    alignment of the tls variables and it adds a pthread_create invocation
    with a user provided stack.
    The test itself is migrated from test-skeleton.c to test-driver.c
    and the missing support functions xpthread_attr_setstack and xposix_memalign
    are added.

Please also verify upstream branch backports:

release/2.30/master - May be required. Please check.
release/2.29/master - May be required. Please check.
release/2.28/master - May be required. Please check.