linux/tools/testing/selftests/vDSO/vdso_test_gettimeofday.c
Mark Brown cd76ca4dd6 selftests: vdso: Use a header file to prototype parse_vdso API
Both vdso_test_gettimeofday and vdso_standalone_test_x86 use the library in
parse_vdso.c but each separately declares the API it offers which is not
ideal. Create a header file with prototypes of the functions and use it in
both the library and the tests to ensure that the same prototypes are used
throughout.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-05-22 11:04:10 -06:00

67 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* vdso_test_gettimeofday.c: Sample code to test parse_vdso.c and
* vDSO gettimeofday()
* Copyright (c) 2014 Andy Lutomirski
*
* Compile with:
* gcc -std=gnu99 vdso_test_gettimeofday.c parse_vdso_gettimeofday.c
*
* Tested on x86, 32-bit and 64-bit. It may work on other architectures, too.
*/
#include <stdint.h>
#include <elf.h>
#include <stdio.h>
#include <sys/auxv.h>
#include <sys/time.h>
#include "../kselftest.h"
#include "parse_vdso.h"
/*
* ARM64's vDSO exports its gettimeofday() implementation with a different
* name and version from other architectures, so we need to handle it as
* a special case.
*/
#if defined(__aarch64__)
const char *version = "LINUX_2.6.39";
const char *name = "__kernel_gettimeofday";
#else
const char *version = "LINUX_2.6";
const char *name = "__vdso_gettimeofday";
#endif
int main(int argc, char **argv)
{
unsigned long sysinfo_ehdr = getauxval(AT_SYSINFO_EHDR);
if (!sysinfo_ehdr) {
printf("AT_SYSINFO_EHDR is not present!\n");
return KSFT_SKIP;
}
vdso_init_from_sysinfo_ehdr(getauxval(AT_SYSINFO_EHDR));
/* Find gettimeofday. */
typedef long (*gtod_t)(struct timeval *tv, struct timezone *tz);
gtod_t gtod = (gtod_t)vdso_sym(version, name);
if (!gtod) {
printf("Could not find %s\n", name);
return KSFT_SKIP;
}
struct timeval tv;
long ret = gtod(&tv, 0);
if (ret == 0) {
printf("The time is %lld.%06lld\n",
(long long)tv.tv_sec, (long long)tv.tv_usec);
} else {
printf("%s failed\n", name);
return KSFT_FAIL;
}
return 0;
}