tools/testing/selftests/bpf/prog_tests/ksyms.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright (c) 2019 Facebook */
   3
   4 #include <test_progs.h>
   5 #include "test_ksyms.skel.h"
   6 #include <sys/stat.h>
   7
   8 static int duration;
   9
  10 static __u64 kallsyms_find(const char *sym)
  11 {
  12         char type, name[500];
  13         __u64 addr, res = 0;
  14         FILE *f;
  15
  16         f = fopen("/proc/kallsyms", "r");
  17         if (CHECK(!f, "kallsyms_fopen", "failed to open: %d\n", errno))
  18                 return 0;
  19
  20         while (fscanf(f, "%llx %c %499s%*[^\n]\n", &addr, &type, name) > 0) {
  21                 if (strcmp(name, sym) == 0) {
  22                         res = addr;
  23                         goto out;
  24                 }
  25         }
  26
  27         CHECK(false, "not_found", "symbol %s not found\n", sym);
  28 out:
  29         fclose(f);
  30         return res;
  31 }
  32
  33 void test_ksyms(void)
  34 {
  35         __u64 per_cpu_start_addr = kallsyms_find("__per_cpu_start");
  36         __u64 link_fops_addr = kallsyms_find("bpf_link_fops");
  37         const char *btf_path = "/sys/kernel/btf/vmlinux";
  38         struct test_ksyms *skel;
  39         struct test_ksyms__data *data;
  40         struct stat st;
  41         __u64 btf_size;
  42         int err;
  43
  44         if (CHECK(stat(btf_path, &st), "stat_btf", "err %d\n", errno))
  45                 return;
  46         btf_size = st.st_size;
  47
  48         skel = test_ksyms__open_and_load();
  49         if (CHECK(!skel, "skel_open", "failed to open and load skeleton\n"))
  50                 return;
  51
  52         err = test_ksyms__attach(skel);
  53         if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
  54                 goto cleanup;
  55
  56         /* trigger tracepoint */
  57         usleep(1);
  58
  59         data = skel->data;
  60         CHECK(data->out__bpf_link_fops != link_fops_addr, "bpf_link_fops",
  61               "got 0x%llx, exp 0x%llx\n",
  62               data->out__bpf_link_fops, link_fops_addr);
  63         CHECK(data->out__bpf_link_fops1 != 0, "bpf_link_fops1",
  64               "got %llu, exp %llu\n", data->out__bpf_link_fops1, (__u64)0);
  65         CHECK(data->out__btf_size != btf_size, "btf_size",
  66               "got %llu, exp %llu\n", data->out__btf_size, btf_size);
  67         CHECK(data->out__per_cpu_start != per_cpu_start_addr, "__per_cpu_start",
  68               "got %llu, exp %llu\n", data->out__per_cpu_start,
  69               per_cpu_start_addr);
  70
  71 cleanup:
  72         test_ksyms__destroy(skel);
  73 }