xref: /linux/tools/perf/util/bpf_map.c (revision 7b8e9264f55a9c320f398e337d215e68cca50131)
1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2 
3 #include "util/bpf_map.h"
4 #include <bpf/bpf.h>
5 #include <bpf/libbpf.h>
6 #include <linux/err.h>
7 #include <linux/kernel.h>
8 #include <errno.h>
9 #include <stdbool.h>
10 #include <stdlib.h>
11 #include <unistd.h>
12 
13 static bool bpf_map__is_per_cpu(enum bpf_map_type type)
14 {
15 	return type == BPF_MAP_TYPE_PERCPU_HASH ||
16 	       type == BPF_MAP_TYPE_PERCPU_ARRAY ||
17 	       type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
18 	       type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE;
19 }
20 
21 static void *bpf_map__alloc_value(const struct bpf_map *map)
22 {
23 	if (bpf_map__is_per_cpu(bpf_map__type(map)))
24 		return malloc(round_up(bpf_map__value_size(map), 8) *
25 			      sysconf(_SC_NPROCESSORS_CONF));
26 
27 	return malloc(bpf_map__value_size(map));
28 }
29 
30 int bpf_map__fprintf(struct bpf_map *map, FILE *fp)
31 {
32 	void *prev_key = NULL, *key, *value;
33 	int fd = bpf_map__fd(map), err;
34 	int printed = 0;
35 
36 	if (fd < 0)
37 		return fd;
38 
39 	err = -ENOMEM;
40 	key = malloc(bpf_map__key_size(map));
41 	if (key == NULL)
42 		goto out;
43 
44 	value = bpf_map__alloc_value(map);
45 	if (value == NULL)
46 		goto out_free_key;
47 
48 	while ((err = bpf_map_get_next_key(fd, prev_key, key) == 0)) {
49 		int intkey = *(int *)key;
50 
51 		if (!bpf_map_lookup_elem(fd, key, value)) {
52 			bool boolval = *(bool *)value;
53 			if (boolval)
54 				printed += fprintf(fp, "[%d] = %d,\n", intkey, boolval);
55 		} else {
56 			printed += fprintf(fp, "[%d] = ERROR,\n", intkey);
57 		}
58 
59 		prev_key = key;
60 	}
61 
62 	if (err == ENOENT)
63 		err = printed;
64 
65 	free(value);
66 out_free_key:
67 	free(key);
68 out:
69 	return err;
70 }
71