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 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 28 unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR); 29 if (!sysinfo_ehdr) { 30 printf("AT_SYSINFO_EHDR is not present!\n"); 31 return KSFT_SKIP; 32 } 33 34 vdso_init_from_sysinfo_ehdr(getauxval(AT_SYSINFO_EHDR)); 35 36 /* Find gettimeofday. */ 37 typedef long (*gtod_t)(struct timeval *tv, struct timezone *tz); 38 gtod_t gtod = (gtod_t)vdso_sym(version, name[0]); 39 40 if (!gtod) { 41 printf("Could not find %s\n", name[0]); 42 return KSFT_SKIP; 43 } 44 45 struct timeval tv; 46 long ret = gtod(&tv, 0); 47 48 if (ret == 0) { 49 printf("The time is %lld.%06lld\n", 50 (long long)tv.tv_sec, (long long)tv.tv_usec); 51 } else { 52 printf("%s failed\n", name[0]); 53 return KSFT_FAIL; 54 } 55 56 return 0; 57 } 58