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1/*2 * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>3 *4 * Permission to use, copy, modify, and distribute this software for any5 * purpose with or without fee is hereby granted, provided that the above6 * copyright notice and this permission notice appear in all copies.7 *8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF14 * 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 is52 * 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 } else91 return 1;92 93 return 0;94}95