bpf_iter_test_kern6.c

 1// SPDX-License-Identifier: GPL-2.0
 2/* Copyright (c) 2020 Facebook */
 3#include <vmlinux.h>
 4#include <bpf/bpf_helpers.h>
 5
 6char _license[] SEC("license") = "GPL";
 7
 8__u32 value_sum = 0;
 9
10SEC("iter/bpf_map_elem")
11int dump_bpf_hash_map(struct bpf_iter__bpf_map_elem *ctx)
12{
13	void *value = ctx->value;
14
15	if (value == (void *)0)
16		return 0;
17
18	/* negative offset, verifier failure. */
19	value_sum += *(__u32 *)(value - 4);
20	return 0;
21}