samples/bpf/tracex4_user.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
   3  */
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <signal.h>
   7 #include <unistd.h>
   8 #include <stdbool.h>
   9 #include <string.h>
  10 #include <time.h>
  11
  12 #include <bpf/bpf.h>
  13 #include <bpf/libbpf.h>
  14
  15 struct pair {
  16         long long val;
  17         __u64 ip;
  18 };
  19
  20 static __u64 time_get_ns(void)
  21 {
  22         struct timespec ts;
  23
  24         clock_gettime(CLOCK_MONOTONIC, &ts);
  25         return ts.tv_sec * 1000000000ull + ts.tv_nsec;
  26 }
  27
  28 static void print_old_objects(int fd)
  29 {
  30         long long val = time_get_ns();
  31         __u64 key, next_key;
  32         struct pair v;
  33
  34         key = write(1, "\e[1;1H\e[2J", 11); /* clear screen */
  35
  36         key = -1;
  37         while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
  38                 bpf_map_lookup_elem(fd, &next_key, &v);
  39                 key = next_key;
  40                 if (val - v.val < 1000000000ll)
  41                         /* object was allocated more then 1 sec ago */
  42                         continue;
  43                 printf("obj 0x%llx is %2lldsec old was allocated at ip %llx\n",
  44                        next_key, (val - v.val) / 1000000000ll, v.ip);
  45         }
  46 }
  47
  48 int main(int ac, char **argv)
  49 {
  50         struct bpf_link *links[2];
  51         struct bpf_program *prog;
  52         struct bpf_object *obj;
  53         char filename[256];
  54         int map_fd, j = 0;
  55
  56         snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
  57         obj = bpf_object__open_file(filename, NULL);
  58         if (libbpf_get_error(obj)) {
  59                 fprintf(stderr, "ERROR: opening BPF object file failed\n");
  60                 return 0;
  61         }
  62
  63         /* load BPF program */
  64         if (bpf_object__load(obj)) {
  65                 fprintf(stderr, "ERROR: loading BPF object file failed\n");
  66                 goto cleanup;
  67         }
  68
  69         map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
  70         if (map_fd < 0) {
  71                 fprintf(stderr, "ERROR: finding a map in obj file failed\n");
  72                 goto cleanup;
  73         }
  74
  75         bpf_object__for_each_program(prog, obj) {
  76                 links[j] = bpf_program__attach(prog);
  77                 if (libbpf_get_error(links[j])) {
  78                         fprintf(stderr, "ERROR: bpf_program__attach failed\n");
  79                         links[j] = NULL;
  80                         goto cleanup;
  81                 }
  82                 j++;
  83         }
  84
  85         while (1) {
  86                 print_old_objects(map_fd);
  87                 sleep(1);
  88         }
  89
  90 cleanup:
  91         for (j--; j >= 0; j--)
  92                 bpf_link__destroy(links[j]);
  93
  94         bpf_object__close(obj);
  95         return 0;
  96 }