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

bug-link-o-tmpfile.c (2074B)

      1/*
      2 * Copyright (c) 2019 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 open(O_TMPFILE), linkat() doesn't screw accounting. */
     17#include <errno.h>
     18#include <sched.h>
     19#include <stdio.h>
     20#include <sys/types.h>
     21#include <sys/stat.h>
     22#include <fcntl.h>
     23#include <sys/mount.h>
     24#include <unistd.h>
     25
     26int main(void)
     27{
     28	int fd;
     29
     30	if (unshare(CLONE_NEWNS) == -1) {
     31		if (errno == ENOSYS || errno == EPERM) {
     32			fprintf(stderr, "error: unshare, errno %d\n", errno);
     33			return 4;
     34		}
     35		fprintf(stderr, "error: unshare, errno %d\n", errno);
     36		return 1;
     37	}
     38	if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
     39		fprintf(stderr, "error: mount '/', errno %d\n", errno);
     40		return 1;
     41	}
     42
     43	/* Our heroes: 1 root inode, 1 O_TMPFILE inode, 1 permanent inode. */
     44	if (mount(NULL, "/tmp", "tmpfs", 0, "nr_inodes=3") == -1) {
     45		fprintf(stderr, "error: mount tmpfs, errno %d\n", errno);
     46		return 1;
     47	}
     48
     49	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
     50	if (fd == -1) {
     51		fprintf(stderr, "error: open 1, errno %d\n", errno);
     52		return 1;
     53	}
     54	if (linkat(fd, "", AT_FDCWD, "/tmp/1", AT_EMPTY_PATH) == -1) {
     55		fprintf(stderr, "error: linkat, errno %d\n", errno);
     56		return 1;
     57	}
     58	close(fd);
     59
     60	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
     61	if (fd == -1) {
     62		fprintf(stderr, "error: open 2, errno %d\n", errno);
     63		return 1;
     64	}
     65
     66	return 0;
     67}