cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

clocksource-switch.c (3490B)

      1/* Clocksource change test
      2 *		by: john stultz (johnstul@us.ibm.com)
      3 *		(C) Copyright IBM 2012
      4 *		Licensed under the GPLv2
      5 *
      6 *  NOTE: This is a meta-test which quickly changes the clocksource and
      7 *  then uses other tests to detect problems. Thus this test requires
      8 *  that the inconsistency-check and nanosleep tests be present in the
      9 *  same directory it is run from.
     10 *
     11 *  To build:
     12 *	$ gcc clocksource-switch.c -o clocksource-switch -lrt
     13 *
     14 *   This program is free software: you can redistribute it and/or modify
     15 *   it under the terms of the GNU General Public License as published by
     16 *   the Free Software Foundation, either version 2 of the License, or
     17 *   (at your option) any later version.
     18 *
     19 *   This program is distributed in the hope that it will be useful,
     20 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
     21 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     22 *   GNU General Public License for more details.
     23 */
     24
     25
     26#include <stdio.h>
     27#include <unistd.h>
     28#include <stdlib.h>
     29#include <sys/time.h>
     30#include <sys/timex.h>
     31#include <time.h>
     32#include <sys/types.h>
     33#include <sys/stat.h>
     34#include <fcntl.h>
     35#include <string.h>
     36#include <sys/wait.h>
     37#include "../kselftest.h"
     38
     39
     40int get_clocksources(char list[][30])
     41{
     42	int fd, i;
     43	size_t size;
     44	char buf[512];
     45	char *head, *tmp;
     46
     47	fd = open("/sys/devices/system/clocksource/clocksource0/available_clocksource", O_RDONLY);
     48
     49	size = read(fd, buf, 512);
     50
     51	close(fd);
     52
     53	for (i = 0; i < 10; i++)
     54		list[i][0] = '\0';
     55
     56	head = buf;
     57	i = 0;
     58	while (head - buf < size) {
     59		/* Find the next space */
     60		for (tmp = head; *tmp != ' '; tmp++) {
     61			if (*tmp == '\n')
     62				break;
     63			if (*tmp == '\0')
     64				break;
     65		}
     66		*tmp = '\0';
     67		strcpy(list[i], head);
     68		head = tmp + 1;
     69		i++;
     70	}
     71
     72	return i-1;
     73}
     74
     75int get_cur_clocksource(char *buf, size_t size)
     76{
     77	int fd;
     78
     79	fd = open("/sys/devices/system/clocksource/clocksource0/current_clocksource", O_RDONLY);
     80
     81	size = read(fd, buf, size);
     82
     83	return 0;
     84}
     85
     86int change_clocksource(char *clocksource)
     87{
     88	int fd;
     89	ssize_t size;
     90
     91	fd = open("/sys/devices/system/clocksource/clocksource0/current_clocksource", O_WRONLY);
     92
     93	if (fd < 0)
     94		return -1;
     95
     96	size = write(fd, clocksource, strlen(clocksource));
     97
     98	if (size < 0)
     99		return -1;
    100
    101	close(fd);
    102	return 0;
    103}
    104
    105
    106int run_tests(int secs)
    107{
    108	int ret;
    109	char buf[255];
    110
    111	sprintf(buf, "./inconsistency-check -t %i", secs);
    112	ret = system(buf);
    113	if (ret)
    114		return ret;
    115	ret = system("./nanosleep");
    116	return ret;
    117}
    118
    119
    120char clocksource_list[10][30];
    121
    122int main(int argv, char **argc)
    123{
    124	char orig_clk[512];
    125	int count, i, status;
    126	pid_t pid;
    127
    128	get_cur_clocksource(orig_clk, 512);
    129
    130	count = get_clocksources(clocksource_list);
    131
    132	if (change_clocksource(clocksource_list[0])) {
    133		printf("Error: You probably need to run this as root\n");
    134		return -1;
    135	}
    136
    137	/* Check everything is sane before we start switching asynchronously */
    138	for (i = 0; i < count; i++) {
    139		printf("Validating clocksource %s\n", clocksource_list[i]);
    140		if (change_clocksource(clocksource_list[i])) {
    141			status = -1;
    142			goto out;
    143		}
    144		if (run_tests(5)) {
    145			status = -1;
    146			goto out;
    147		}
    148	}
    149
    150
    151	printf("Running Asynchronous Switching Tests...\n");
    152	pid = fork();
    153	if (!pid)
    154		return run_tests(60);
    155
    156	while (pid != waitpid(pid, &status, WNOHANG))
    157		for (i = 0; i < count; i++)
    158			if (change_clocksource(clocksource_list[i])) {
    159				status = -1;
    160				goto out;
    161			}
    162out:
    163	change_clocksource(orig_clk);
    164
    165	if (status)
    166		return ksft_exit_fail();
    167	return ksft_exit_pass();
    168}