samples/bpf/spintest_user.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <stdio.h>
   3 #include <unistd.h>
   4 #include <string.h>
   5 #include <assert.h>
   6 #include <bpf/libbpf.h>
   7 #include <bpf/bpf.h>
   8 #include "trace_helpers.h"
   9
  10 int main(int ac, char **argv)
  11 {
  12         struct bpf_object *obj = NULL;
  13         struct bpf_link *links[20];
  14         long key, next_key, value;
  15         struct bpf_program *prog;
  16         int map_fd, i, j = 0;
  17         char filename[256];
  18         struct ksym *sym;
  19
  20         if (load_kallsyms()) {
  21                 printf("failed to process /proc/kallsyms\n");
  22                 return 2;
  23         }
  24
  25         snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
  26         obj = bpf_object__open_file(filename, NULL);
  27         if (libbpf_get_error(obj)) {
  28                 fprintf(stderr, "ERROR: opening BPF object file failed\n");
  29                 obj = NULL;
  30                 goto cleanup;
  31         }
  32
  33         /* load BPF program */
  34         if (bpf_object__load(obj)) {
  35                 fprintf(stderr, "ERROR: loading BPF object file failed\n");
  36                 goto cleanup;
  37         }
  38
  39         map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
  40         if (map_fd < 0) {
  41                 fprintf(stderr, "ERROR: finding a map in obj file failed\n");
  42                 goto cleanup;
  43         }
  44
  45         bpf_object__for_each_program(prog, obj) {
  46                 links[j] = bpf_program__attach(prog);
  47                 if (libbpf_get_error(links[j])) {
  48                         fprintf(stderr, "bpf_program__attach failed\n");
  49                         links[j] = NULL;
  50                         goto cleanup;
  51                 }
  52                 j++;
  53         }
  54
  55         for (i = 0; i < 5; i++) {
  56                 key = 0;
  57                 printf("kprobing funcs:");
  58                 while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
  59                         bpf_map_lookup_elem(map_fd, &next_key, &value);
  60                         assert(next_key == value);
  61                         sym = ksym_search(value);
  62                         key = next_key;
  63                         if (!sym) {
  64                                 printf("ksym not found. Is kallsyms loaded?\n");
  65                                 continue;
  66                         }
  67
  68                         printf(" %s", sym->name);
  69                 }
  70                 if (key)
  71                         printf("\n");
  72                 key = 0;
  73                 while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0)
  74                         bpf_map_delete_elem(map_fd, &next_key);
  75                 sleep(1);
  76         }
  77
  78 cleanup:
  79         for (j--; j >= 0; j--)
  80                 bpf_link__destroy(links[j]);
  81
  82         bpf_object__close(obj);
  83         return 0;
  84 }