1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2019 Facebook */ 3 #include <linux/bpf.h> 4 #include <bpf/bpf_helpers.h> 5 #include <bpf/bpf_tracing.h> 6 7 struct sk_buff { 8 unsigned int len; 9 }; 10 11 __u64 test_result = 0; 12 13 SEC("fexit/test_pkt_md_access") BPF_PROG(test_main2,struct sk_buff * skb,int ret)14 int BPF_PROG(test_main2, struct sk_buff *skb, int ret) 15 { 16 int len; 17 18 __builtin_preserve_access_index(({ 19 len = skb->len; 20 })); 21 if (len != 74 || ret != 0) 22 return 0; 23 24 test_result = 1; 25 return 0; 26 } 27 char _license[] SEC("license") = "GPL"; 28