1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * vdso_test_gettimeofday.c: Sample code to test parse_vdso.c and
4 * vDSO gettimeofday()
5 * Copyright (c) 2014 Andy Lutomirski
6 *
7 * Compile with:
8 * gcc -std=gnu99 vdso_test_gettimeofday.c parse_vdso_gettimeofday.c
9 *
10 * Tested on x86, 32-bit and 64-bit. It may work on other architectures, too.
11 */
12
13 #include <stdint.h>
14 #include <elf.h>
15 #include <stdio.h>
16 #include <sys/auxv.h>
17 #include <sys/time.h>
18
19 #include "../kselftest.h"
20 #include "parse_vdso.h"
21 #include "vdso_config.h"
22 #include "vdso_call.h"
23
main(int argc,char ** argv)24 int main(int argc, char **argv)
25 {
26 const char *version = versions[VDSO_VERSION];
27 const char **name = (const char **)&names[VDSO_NAMES];
28
29 unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
30 if (!sysinfo_ehdr) {
31 printf("AT_SYSINFO_EHDR is not present!\n");
32 return KSFT_SKIP;
33 }
34
35 vdso_init_from_sysinfo_ehdr(getauxval(AT_SYSINFO_EHDR));
36
37 /* Find gettimeofday. */
38 typedef long (*gtod_t)(struct timeval *tv, struct timezone *tz);
39 gtod_t gtod = (gtod_t)vdso_sym(version, name[0]);
40
41 if (!gtod) {
42 printf("Could not find %s\n", name[0]);
43 return KSFT_SKIP;
44 }
45
46 struct timeval tv;
47 long ret = VDSO_CALL(gtod, 2, &tv, 0);
48
49 if (ret == 0) {
50 printf("The time is %lld.%06lld\n",
51 (long long)tv.tv_sec, (long long)tv.tv_usec);
52 } else {
53 printf("%s failed\n", name[0]);
54 return KSFT_FAIL;
55 }
56
57 return 0;
58 }
59