Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
19typedef long (*getcpu_t)(unsigned int *, unsigned int *, void *);
20
21int main(int argc, char **argv)
22{
23 const char *version = versions[VDSO_VERSION];
24 const char **name = (const char **)&names[VDSO_NAMES];
25 unsigned long sysinfo_ehdr;
26 unsigned int cpu, node;
27 getcpu_t get_cpu;
28 long ret;
29
30 sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
31 if (!sysinfo_ehdr) {
32 printf("AT_SYSINFO_EHDR is not present!\n");
33 return KSFT_SKIP;
34 }
35
36 vdso_init_from_sysinfo_ehdr(getauxval(AT_SYSINFO_EHDR));
37
38 get_cpu = (getcpu_t)vdso_sym(version, name[4]);
39 if (!get_cpu) {
40 printf("Could not find %s\n", name[4]);
41 return KSFT_SKIP;
42 }
43
44 ret = VDSO_CALL(get_cpu, 3, &cpu, &node, 0);
45 if (ret == 0) {
46 printf("Running on CPU %u node %u\n", cpu, node);
47 } else {
48 printf("%s failed\n", name[4]);
49 return KSFT_FAIL;
50 }
51
52 return 0;
53}