tjh.dev
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
19struct getcpu_cache;
20typedef long (*getcpu_t)(unsigned int *, unsigned int *,
21 struct getcpu_cache *);
22
23int 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}