1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
4 #include <bpf/bpf_helpers.h>
5 #include <bpf/bpf_tracing.h>
7 char _license[] SEC("license") = "GPL";
16 __uint(type, BPF_MAP_TYPE_HASH);
17 __uint(max_entries, 3);
18 __type(key, struct key_t);
20 } hashmap1 SEC(".maps");
23 __uint(type, BPF_MAP_TYPE_HASH);
24 __uint(max_entries, 3);
27 } hashmap2 SEC(".maps");
30 __uint(type, BPF_MAP_TYPE_HASH);
31 __uint(max_entries, 3);
32 __type(key, struct key_t);
34 } hashmap3 SEC(".maps");
36 /* will set before prog run */
37 bool in_test_mode = 0;
39 /* will collect results during prog run */
40 __u32 key_sum_a = 0, key_sum_b = 0, key_sum_c = 0;
43 SEC("iter/bpf_map_elem")
44 int dump_bpf_hash_map(struct bpf_iter__bpf_map_elem *ctx)
46 struct seq_file *seq = ctx->meta->seq;
47 __u32 seq_num = ctx->meta->seq_num;
48 struct bpf_map *map = ctx->map;
49 struct key_t *key = ctx->key;
50 __u64 *val = ctx->value;
53 /* test mode is used by selftests to
54 * test functionality of bpf_hash_map iter.
56 * the above hashmap1 will have correct size
57 * and will be accepted, hashmap2 and hashmap3
58 * should be rejected due to smaller key/value
61 if (key == (void *)0 || val == (void *)0)
71 /* non-test mode, the map is prepared with the
72 * below bpftool command sequence:
73 * bpftool map create /sys/fs/bpf/m1 type hash \
74 * key 12 value 8 entries 3 name map1
75 * bpftool map update id 77 key 0 0 0 1 0 0 0 0 0 0 0 1 \
76 * value 0 0 0 1 0 0 0 1
77 * bpftool map update id 77 key 0 0 0 1 0 0 0 0 0 0 0 2 \
78 * value 0 0 0 1 0 0 0 2
79 * The bpftool iter command line:
80 * bpftool iter pin ./bpf_iter_bpf_hash_map.o /sys/fs/bpf/p1 \
82 * The below output will be:
84 * 77: (1000000 0 2000000) (200000001000000)
85 * 77: (1000000 0 1000000) (100000001000000)
89 BPF_SEQ_PRINTF(seq, "map dump starts\n");
91 if (key == (void *)0 || val == (void *)0) {
92 BPF_SEQ_PRINTF(seq, "map dump ends\n");
96 BPF_SEQ_PRINTF(seq, "%d: (%x %d %x) (%llx)\n", map->id,
97 key->a, key->b, key->c, *val);