tools/testing/selftests/vDSO/vdso_test_getcpu.c

   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 #include "vdso_config.h"
  17 #include "vdso_call.h"
  18
  19 struct getcpu_cache;
  20 typedef long (*getcpu_t)(unsigned int *, unsigned int *,
  21                          struct getcpu_cache *);
  22
  23 int main(int argc, char **argv)
  24 {
  25         const char *version = versions[VDSO_VERSION];
  26         const char **name = (const char **)&names[VDSO_NAMES];
  27         unsigned long sysinfo_ehdr;
  28         unsigned int cpu, node;
  29         getcpu_t get_cpu;
  30         long ret;
  31
  32         sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
  33         if (!sysinfo_ehdr) {
  34                 printf("AT_SYSINFO_EHDR is not present!\n");
  35                 return KSFT_SKIP;
  36         }
  37
  38         vdso_init_from_sysinfo_ehdr(getauxval(AT_SYSINFO_EHDR));
  39
  40         get_cpu = (getcpu_t)vdso_sym(version, name[4]);
  41         if (!get_cpu) {
  42                 printf("Could not find %s\n", name[4]);
  43                 return KSFT_SKIP;
  44         }
  45
  46         ret = VDSO_CALL(get_cpu, 3, &cpu, &node, 0);
  47         if (ret == 0) {
  48                 printf("Running on CPU %u node %u\n", cpu, node);
  49         } else {
  50                 printf("%s failed\n", name[4]);
  51                 return KSFT_FAIL;
  52         }
  53
  54         return 0;
  55 }