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

proc-tid0.c (1766B)

      1/*
      2 * Copyright (c) 2021 Alexey Dobriyan <adobriyan@gmail.com>
      3 *
      4 * Permission to use, copy, modify, and distribute this software for any
      5 * purpose with or without fee is hereby granted, provided that the above
      6 * copyright notice and this permission notice appear in all copies.
      7 *
      8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     15 */
     16// Test that /proc/*/task never contains "0".
     17#include <sys/types.h>
     18#include <dirent.h>
     19#include <signal.h>
     20#include <stdio.h>
     21#include <stdlib.h>
     22#include <string.h>
     23#include <unistd.h>
     24#include <pthread.h>
     25
     26static pid_t pid = -1;
     27
     28static void atexit_hook(void)
     29{
     30	if (pid > 0) {
     31		kill(pid, SIGKILL);
     32	}
     33}
     34
     35static void *f(void *_)
     36{
     37	return NULL;
     38}
     39
     40static void sigalrm(int _)
     41{
     42	exit(0);
     43}
     44
     45int main(void)
     46{
     47	pid = fork();
     48	if (pid == 0) {
     49		/* child */
     50		while (1) {
     51			pthread_t pth;
     52			pthread_create(&pth, NULL, f, NULL);
     53			pthread_join(pth, NULL);
     54		}
     55	} else if (pid > 0) {
     56		/* parent */
     57		atexit(atexit_hook);
     58
     59		char buf[64];
     60		snprintf(buf, sizeof(buf), "/proc/%u/task", pid);
     61
     62		signal(SIGALRM, sigalrm);
     63		alarm(1);
     64
     65		while (1) {
     66			DIR *d = opendir(buf);
     67			struct dirent *de;
     68			while ((de = readdir(d))) {
     69				if (strcmp(de->d_name, "0") == 0) {
     70					exit(1);
     71				}
     72			}
     73			closedir(d);
     74		}
     75
     76		return 0;
     77	} else {
     78		perror("fork");
     79		return 1;
     80	}
     81}