[FAQ]load bpf script run error log, need guidance

[gaowayne]

[root@ch7-smc-2407 bpf]# ./load.sh

• set -e
• sudo mount -t bpf bpf /sys/fs/bpf/
• clang -O2 -g -target bpf -c bpf_sockops.c -o bpf_sockops.o
• sudo bpftool prog load bpf_sockops.o /sys/fs/bpf/bpf_sockops libbpf: elf: skipping unrecognized data section(8) .rodata.str1.1 libbpf: elf: skipping unrecognized data section(18) .eh_frame libbpf: elf: skipping relo section(19) .rel.eh_frame for section(18) .eh_frame
• sudo bpftool cgroup attach /sys/fs/cgroup/unified/ sock_ops pinned /sys/fs/bpf/bpf_sockops Error: can't open cgroup /sys/fs/cgroup/unified/ [root@ch7-smc-2407 bpf]#

[gaowayne]

if I do not need test inside cgroup, which steps I can skip to run very basic function of socket redirection. if I only want to intercept this for loopback NIC, what kind of code I should change?