tools/perf/util/bpf_map.c

   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         err = -ENOMEM;
  39         key = malloc(bpf_map__key_size(map));
  40         if (key == NULL)
  41                 goto out;
  42
  43         value = bpf_map__alloc_value(map);
  44         if (value == NULL)
  45                 goto out_free_key;
  46
  47         while ((err = bpf_map_get_next_key(fd, prev_key, key) == 0)) {
  48                 int intkey = *(int *)key;
  49
  50                 if (!bpf_map_lookup_elem(fd, key, value)) {
  51                         bool boolval = *(bool *)value;
  52                         if (boolval)
  53                                 printed += fprintf(fp, "[%d] = %d,\n", intkey, boolval);
  54                 } else {
  55                         printed += fprintf(fp, "[%d] = ERROR,\n", intkey);
  56                 }
  57
  58                 prev_key = key;
  59         }
  60
  61         if (err == ENOENT)
  62                 err = printed;
  63
  64         free(value);
  65 out_free_key:
  66         free(key);
  67 out:
  68         return err;
  69 }