Cregit: Linux 7.2: tailcall_bpf2bpf

Contributors: 6
Author	Tokens	Token Proportion	Commits	Commit Proportion
Leon Huayra	254	85.23%	1	16.67%
Yonghong Song	30	10.07%	1	16.67%
Ilya Leoshkevich	6	2.01%	1	16.67%
Cupertino Miranda	5	1.68%	1	16.67%
Jiri Olsa	2	0.67%	1	16.67%
Daniel Borkmann	1	0.34%	1	16.67%
Total	298		6

// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "bpf_misc.h"
#include "bpf_test_utils.h"

int classifier_0(struct __sk_buff *skb);

struct {
	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
	__uint(max_entries, 1);
	__uint(key_size, sizeof(__u32));
	__array(values, void (void));
} jmp_table0 SEC(".maps") = {
	.values = {
		[0] = (void *) &classifier_0,
	},
};

struct {
	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
	__uint(max_entries, 1);
	__uint(key_size, sizeof(__u32));
	__array(values, void (void));
} jmp_table1 SEC(".maps") = {
	.values = {
		[0] = (void *) &classifier_0,
	},
};

int count = 0;

static __noinline
int subprog_tail(struct __sk_buff *skb, void *jmp_table)
{
	int ret = 0;

	bpf_tail_call_static(skb, jmp_table, 0);
	barrier_var(ret);
	return ret;
}

__auxiliary
SEC("tc")
int classifier_0(struct __sk_buff *skb)
{
	int ret1, ret2;

	count++;
	ret1 = subprog_tail(skb, &jmp_table0);
	ret2 = subprog_tail(skb, &jmp_table1);
	__sink(ret1);
	__sink(ret2);
	return count;
}

__success
__retval(33)
SEC("tc")
int tailcall_bpf2bpf_hierarchy_3(struct __sk_buff *skb)
{
	int ret = 0;

	clobber_regs_stack();

	bpf_tail_call_static(skb, &jmp_table0, 0);

	__sink(ret);
	return ret;
}

char __license[] SEC("license") = "GPL";

tailcall_bpf2bpf_hierarchy3.c