linux-stable/tools/testing/selftests/bpf/progs/tailcall_bpf2bpf6.c

43 lines
801 B
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#define __unused __attribute__((unused))
struct {
__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
__uint(max_entries, 1);
__uint(key_size, sizeof(__u32));
__uint(value_size, sizeof(__u32));
} jmp_table SEC(".maps");
int done = 0;
SEC("tc")
int classifier_0(struct __sk_buff *skb __unused)
{
done = 1;
return 0;
}
static __noinline
int subprog_tail(struct __sk_buff *skb)
{
/* Don't propagate the constant to the caller */
volatile int ret = 1;
bpf_tail_call_static(skb, &jmp_table, 0);
return ret;
}
SEC("tc")
int entry(struct __sk_buff *skb)
{
/* Have data on stack which size is not a multiple of 8 */
volatile char arr[1] = {};
return subprog_tail(skb);
}
char __license[] SEC("license") = "GPL";