When functions called by the trampoline panic, the backtrace that is printed stops at the trampoline, because the trampoline does not store its caller's frame address (backchain) on stack; it also stores the return address at a wrong location. Store both the same way as is already done for the regular eBPF programs. Fixes: 528eb2cb87bc ("s390/bpf: Implement arch_prepare_bpf_trampoline()") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20231010203512.385819-3-iii@linux.ibm.com