xref: /openbmc/linux/tools/perf/util/bpf_map.c (revision 9a29f5fc)
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 <stdbool.h>
9 #include <stdlib.h>
10 #include <unistd.h>
11 
12 static bool bpf_map__is_per_cpu(enum bpf_map_type type)
13 {
14 	return type == BPF_MAP_TYPE_PERCPU_HASH ||
15 	       type == BPF_MAP_TYPE_PERCPU_ARRAY ||
16 	       type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
17 	       type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE;
18 }
19 
20 static void *bpf_map__alloc_value(const struct bpf_map *map)
21 {
22 	if (bpf_map__is_per_cpu(bpf_map__type(map)))
23 		return malloc(round_up(bpf_map__value_size(map), 8) *
24 			      sysconf(_SC_NPROCESSORS_CONF));
25 
26 	return malloc(bpf_map__value_size(map));
27 }
28 
29 int bpf_map__fprintf(struct bpf_map *map, FILE *fp)
30 {
31 	void *prev_key = NULL, *key, *value;
32 	int fd = bpf_map__fd(map), err;
33 	int printed = 0;
34 
35 	if (fd < 0)
36 		return fd;
37 
38 	if (!map)
39 		return PTR_ERR(map);
40 
41 	err = -ENOMEM;
42 	key = malloc(bpf_map__key_size(map));
43 	if (key == NULL)
44 		goto out;
45 
46 	value = bpf_map__alloc_value(map);
47 	if (value == NULL)
48 		goto out_free_key;
49 
50 	while ((err = bpf_map_get_next_key(fd, prev_key, key) == 0)) {
51 		int intkey = *(int *)key;
52 
53 		if (!bpf_map_lookup_elem(fd, key, value)) {
54 			bool boolval = *(bool *)value;
55 			if (boolval)
56 				printed += fprintf(fp, "[%d] = %d,\n", intkey, boolval);
57 		} else {
58 			printed += fprintf(fp, "[%d] = ERROR,\n", intkey);
59 		}
60 
61 		prev_key = key;
62 	}
63 
64 	if (err == ENOENT)
65 		err = printed;
66 
67 	free(value);
68 out_free_key:
69 	free(key);
70 out:
71 	return err;
72 }
73