LXR linux/samples/bpf/tracex4

   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#include <sys/resource.h>
  12
  13#include <bpf/bpf.h>
  14#include <bpf/libbpf.h>
  15
  16struct pair {
  17        long long val;
  18        __u64 ip;
  19};
  20
  21static __u64 time_get_ns(void)
  22{
  23        struct timespec ts;
  24
  25        clock_gettime(CLOCK_MONOTONIC, &ts);
  26        return ts.tv_sec * 1000000000ull + ts.tv_nsec;
  27}
  28
  29static void print_old_objects(int fd)
  30{
  31        long long val = time_get_ns();
  32        __u64 key, next_key;
  33        struct pair v;
  34
  35        key = write(1, "\e[1;1H\e[2J", 11); /* clear screen */
  36
  37        key = -1;
  38        while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
  39                bpf_map_lookup_elem(fd, &next_key, &v);
  40                key = next_key;
  41                if (val - v.val < 1000000000ll)
  42                        /* object was allocated more then 1 sec ago */
  43                        continue;
  44                printf("obj 0x%llx is %2lldsec old was allocated at ip %llx\n",
  45                       next_key, (val - v.val) / 1000000000ll, v.ip);
  46        }
  47}
  48
  49int main(int ac, char **argv)
  50{
  51        struct bpf_link *links[2];
  52        struct bpf_program *prog;
  53        struct bpf_object *obj;
  54        char filename[256];
  55        int map_fd, i, j = 0;
  56
  57        snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
  58        obj = bpf_object__open_file(filename, NULL);
  59        if (libbpf_get_error(obj)) {
  60                fprintf(stderr, "ERROR: opening BPF object file failed\n");
  61                return 0;
  62        }
  63
  64        /* load BPF program */
  65        if (bpf_object__load(obj)) {
  66                fprintf(stderr, "ERROR: loading BPF object file failed\n");
  67                goto cleanup;
  68        }
  69
  70        map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
  71        if (map_fd < 0) {
  72                fprintf(stderr, "ERROR: finding a map in obj file failed\n");
  73                goto cleanup;
  74        }
  75
  76        bpf_object__for_each_program(prog, obj) {
  77                links[j] = bpf_program__attach(prog);
  78                if (libbpf_get_error(links[j])) {
  79                        fprintf(stderr, "ERROR: bpf_program__attach failed\n");
  80                        links[j] = NULL;
  81                        goto cleanup;
  82                }
  83                j++;
  84        }
  85
  86        for (i = 0; ; i++) {
  87                print_old_objects(map_fd);
  88                sleep(1);
  89        }
  90
  91cleanup:
  92        for (j--; j >= 0; j--)
  93                bpf_link__destroy(links[j]);
  94
  95        bpf_object__close(obj);
  96        return 0;
  97}
  98