LXR linux/tools/testing/selftests/vDSO/vdso_test

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * vdso_test_getcpu.c: Sample code to test parse_vdso.c and vDSO getcpu()
   4 *
   5 * Copyright (c) 2020 Arm Ltd
   6 */
   7
   8#include <stdint.h>
   9#include <elf.h>
  10#include <stdio.h>
  11#include <sys/auxv.h>
  12#include <sys/time.h>
  13
  14#include "../kselftest.h"
  15#include "parse_vdso.h"
  16
  17const char *version = "LINUX_2.6";
  18const char *name = "__vdso_getcpu";
  19
  20struct getcpu_cache;
  21typedef long (*getcpu_t)(unsigned int *, unsigned int *,
  22                         struct getcpu_cache *);
  23
  24int main(int argc, char **argv)
  25{
  26        unsigned long sysinfo_ehdr;
  27        unsigned int cpu, node;
  28        getcpu_t get_cpu;
  29        long ret;
  30
  31        sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
  32        if (!sysinfo_ehdr) {
  33                printf("AT_SYSINFO_EHDR is not present!\n");
  34                return KSFT_SKIP;
  35        }
  36
  37        vdso_init_from_sysinfo_ehdr(getauxval(AT_SYSINFO_EHDR));
  38
  39        get_cpu = (getcpu_t)vdso_sym(version, name);
  40        if (!get_cpu) {
  41                printf("Could not find %s\n", name);
  42                return KSFT_SKIP;
  43        }
  44
  45        ret = get_cpu(&cpu, &node, 0);
  46        if (ret == 0) {
  47                printf("Running on CPU %u node %u\n", cpu, node);
  48        } else {
  49                printf("%s failed\n", name);
  50                return KSFT_FAIL;
  51        }
  52
  53        return 0;
  54}
  55