xref: /OK3568_Linux_fs/kernel/tools/testing/selftests/bpf/progs/loop5.c (revision 4882a59341e53eb6f0b4789bf948001014eff981) 
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun // Copyright (c) 2019 Facebook
3*4882a593Smuzhiyun #include <linux/bpf.h>
4*4882a593Smuzhiyun #include <bpf/bpf_helpers.h>
5*4882a593Smuzhiyun #define barrier() __asm__ __volatile__("": : :"memory")
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun char _license[] SEC("license") = "GPL";
8*4882a593Smuzhiyun 
9*4882a593Smuzhiyun SEC("socket")
while_true(volatile struct __sk_buff * skb)10*4882a593Smuzhiyun int while_true(volatile struct __sk_buff* skb)
11*4882a593Smuzhiyun {
12*4882a593Smuzhiyun 	int i = 0;
13*4882a593Smuzhiyun 
14*4882a593Smuzhiyun 	while (1) {
15*4882a593Smuzhiyun 		if (skb->len)
16*4882a593Smuzhiyun 			i += 3;
17*4882a593Smuzhiyun 		else
18*4882a593Smuzhiyun 			i += 7;
19*4882a593Smuzhiyun 		if (i == 9)
20*4882a593Smuzhiyun 			break;
21*4882a593Smuzhiyun 		barrier();
22*4882a593Smuzhiyun 		if (i == 10)
23*4882a593Smuzhiyun 			break;
24*4882a593Smuzhiyun 		barrier();
25*4882a593Smuzhiyun 		if (i == 13)
26*4882a593Smuzhiyun 			break;
27*4882a593Smuzhiyun 		barrier();
28*4882a593Smuzhiyun 		if (i == 14)
29*4882a593Smuzhiyun 			break;
30*4882a593Smuzhiyun 	}
31*4882a593Smuzhiyun 	return i;
32*4882a593Smuzhiyun }
33