cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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proc-self-map-files-002.c (2792B)

      1/*
      2 * Copyright © 2018 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 readlink /proc/self/map_files/... with minimum address. */
     17#include <errno.h>
     18#include <sys/types.h>
     19#include <sys/stat.h>
     20#include <fcntl.h>
     21#include <stdio.h>
     22#include <unistd.h>
     23#include <sys/mman.h>
     24#include <stdlib.h>
     25
     26static void pass(const char *fmt, unsigned long a, unsigned long b)
     27{
     28	char name[64];
     29	char buf[64];
     30
     31	snprintf(name, sizeof(name), fmt, a, b);
     32	if (readlink(name, buf, sizeof(buf)) == -1)
     33		exit(1);
     34}
     35
     36static void fail(const char *fmt, unsigned long a, unsigned long b)
     37{
     38	char name[64];
     39	char buf[64];
     40
     41	snprintf(name, sizeof(name), fmt, a, b);
     42	if (readlink(name, buf, sizeof(buf)) == -1 && errno == ENOENT)
     43		return;
     44	exit(1);
     45}
     46
     47int main(void)
     48{
     49	const int PAGE_SIZE = sysconf(_SC_PAGESIZE);
     50	/*
     51	 * va_max must be enough bigger than vm.mmap_min_addr, which is
     52	 * 64KB/32KB by default. (depends on CONFIG_LSM_MMAP_MIN_ADDR)
     53	 */
     54	const unsigned long va_max = 1UL << 20;
     55	unsigned long va;
     56	void *p;
     57	int fd;
     58	unsigned long a, b;
     59
     60	fd = open("/dev/zero", O_RDONLY);
     61	if (fd == -1)
     62		return 1;
     63
     64	for (va = 0; va < va_max; va += PAGE_SIZE) {
     65		p = mmap((void *)va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
     66		if (p == (void *)va)
     67			break;
     68	}
     69	if (va == va_max) {
     70		fprintf(stderr, "error: mmap doesn't like you\n");
     71		return 1;
     72	}
     73
     74	a = (unsigned long)p;
     75	b = (unsigned long)p + PAGE_SIZE;
     76
     77	pass("/proc/self/map_files/%lx-%lx", a, b);
     78	fail("/proc/self/map_files/ %lx-%lx", a, b);
     79	fail("/proc/self/map_files/%lx -%lx", a, b);
     80	fail("/proc/self/map_files/%lx- %lx", a, b);
     81	fail("/proc/self/map_files/%lx-%lx ", a, b);
     82	fail("/proc/self/map_files/0%lx-%lx", a, b);
     83	fail("/proc/self/map_files/%lx-0%lx", a, b);
     84	if (sizeof(long) == 4) {
     85		fail("/proc/self/map_files/100000000%lx-%lx", a, b);
     86		fail("/proc/self/map_files/%lx-100000000%lx", a, b);
     87	} else if (sizeof(long) == 8) {
     88		fail("/proc/self/map_files/10000000000000000%lx-%lx", a, b);
     89		fail("/proc/self/map_files/%lx-10000000000000000%lx", a, b);
     90	} else
     91		return 1;
     92
     93	return 0;
     94}