Implement bpf fsession for the s390 architecture.

Changes v2 -> v1:
* keep LGHI as it was in the 1st patch
* fix up the comment style
* remove the unnecessary checking of fentry->nr_links and fexit->nr_links
  in the 2nd patch
* v1: https://lore.kernel.org/bpf/20260223084022.653186-1-dongml2@chinatelecom.cn/

Menglong Dong (3):
  bpf,s390: introduce emit_store_stack_imm64() for trampoline
  bpf,s390: add fsession support for trampolines
  selftests/bpf: factor out get_func_* tests for fsession

 arch/s390/net/bpf_jit_comp.c                  | 95 ++++++++++++++-----
 .../bpf/prog_tests/get_func_args_test.c       | 25 ++++-
 .../bpf/prog_tests/get_func_ip_test.c         | 28 +++++-
 .../bpf/progs/get_func_args_fsession_test.c   | 37 ++++++++
 .../selftests/bpf/progs/get_func_args_test.c  | 38 --------
 .../bpf/progs/get_func_ip_fsession_test.c     | 21 ++++
 .../selftests/bpf/progs/get_func_ip_test.c    | 23 -----
 7 files changed, 178 insertions(+), 89 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/get_func_args_fsession_test.c
 create mode 100644 tools/testing/selftests/bpf/progs/get_func_ip_fsession_test.c

-- 
2.53.0