rhel9's version of pahole doesn't properly generate VARs for percpu symbols on non-x86_64 architectures. Found this while running bpf selftests on aarch64. Looks like the following commit fixes the issue (and can be cherry-picked cleanly onto v1.22)

commit 16a7acaba446612135ba674a51cdda6bfcc34667
Author: Ilya Leoshkevich <iii.com>
Date:   Tue Oct 12 04:26:37 2021 +0200

    btf_encoder: Fix handling of percpu symbols on s390

    pahole does not generate VARs for percpu symbols on s390. A percpu
    symbol definition on a typical x86_64 kernel looks like this:

      [33] .data..percpu     PROGBITS         0000000000000000  01c00000
                                              ^^^^^^^^^^^^^^^^ sh_addr
      LOAD           0x0000000001c00000 0x0000000000000000 0x000000000286f000
                                        ^^^^^^^^^^^^^^^^^^ p_vaddr
     13559: 000000000001ba50     4 OBJECT  LOCAL  DEFAULT   33 cpu_profile_flip
            ^^^^^^^^^^^^^^^^ st_value

    Most importantly, .data..percpu's sh_addr is 0, and this is what pahole
    is currently assuming. However, on s390 this is different:

       [37] .data..percpu     PROGBITS         00000000019cd000  018ce000
                                               ^^^^^^^^^^^^^^^^ sh_addr
      LOAD           0x000000000136e000 0x000000000146d000 0x000000000146d000
                                        ^^^^^^^^^^^^^^^^^^ p_vaddr
    80377: 0000000001ba1440     4 OBJECT  WEAK   DEFAULT   37 cpu_profile_flip
           ^^^^^^^^^^^^^^^^ st_value

    Fix by restructuring the code to always use section-relative offsets for
    symbols. Change the comment to focus on this invariant.

    Signed-off-by: Ilya Leoshkevich <iii.com>
    Cc: Alexei Starovoitov <ast>
    Cc: Andrii Nakryiko <andrii.nakryiko>
    Cc: Daniel Borkmann <daniel>
    Cc: Heiko Carstens <hca.com>
    Cc: Vasily Gorbik <gor.com>
    Cc: bpf.org
    Cc: dwarves.org
    Signed-off-by: Arnaldo Carvalho de Melo <acme>

Without this commit:
    # ./pahole --btf_encode_detached=vml.btf /mnt/testarea/bpf/bpf-next/vmlinux; bpftool btf dump file vml.btf | grep -w VAR | wc -l
    0

With commit applied:
    # ./pahole --btf_encode_detached=vml.btf /mnt/testarea/bpf/bpf-next/vmlinux; bpftool btf dump file vml.btf | grep -w VAR | wc -l
    586