xref: /linux/tools/testing/selftests/vDSO/vdso_test_getcpu.c (revision d53b8e36925256097a08d7cb749198d85cbf9b2b)
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 
18 struct getcpu_cache;
19 typedef long (*getcpu_t)(unsigned int *, unsigned int *,
20 			 struct getcpu_cache *);
21 
22 int main(int argc, char **argv)
23 {
24 	const char *version = versions[VDSO_VERSION];
25 	const char **name = (const char **)&names[VDSO_NAMES];
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[4]);
40 	if (!get_cpu) {
41 		printf("Could not find %s\n", name[4]);
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[4]);
50 		return KSFT_FAIL;
51 	}
52 
53 	return 0;
54 }
55