/* * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* Test readlink /proc/self/map_files/... with minimum address. */ #include <errno.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <stdio.h> #include <unistd.h> #include <sys/mman.h> #include <stdlib.h> static void pass(const char *fmt, unsigned long a, unsigned long b) { char name[64]; char buf[64]; snprintf(name, sizeof(name), fmt, a, b); if (readlink(name, buf, sizeof(buf)) == -1) exit(1); } static void fail(const char *fmt, unsigned long a, unsigned long b) { char name[64]; char buf[64]; snprintf(name, sizeof(name), fmt, a, b); if (readlink(name, buf, sizeof(buf)) == -1 && errno == ENOENT) return; exit(1); } int main(void) { const int PAGE_SIZE = sysconf(_SC_PAGESIZE); /* * va_max must be enough bigger than vm.mmap_min_addr, which is * 64KB/32KB by default. (depends on CONFIG_LSM_MMAP_MIN_ADDR) */ const unsigned long va_max = 1UL << 20; unsigned long va; void *p; int fd; unsigned long a, b; fd = open("/dev/zero", O_RDONLY); if (fd == -1) return 1; for (va = 0; va < va_max; va += PAGE_SIZE) { p = mmap((void *)va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0); if (p == (void *)va) break; } if (va == va_max) { fprintf(stderr, "error: mmap doesn't like you\n"); return 1; } a = (unsigned long)p; b = (unsigned long)p + PAGE_SIZE; pass("/proc/self/map_files/%lx-%lx", a, b); fail("/proc/self/map_files/ %lx-%lx", a, b); fail("/proc/self/map_files/%lx -%lx", a, b); fail("/proc/self/map_files/%lx- %lx", a, b); fail("/proc/self/map_files/%lx-%lx ", a, b); fail("/proc/self/map_files/0%lx-%lx", a, b); fail("/proc/self/map_files/%lx-0%lx", a, b); if (sizeof(long) == 4) { fail("/proc/self/map_files/100000000%lx-%lx", a, b); fail("/proc/self/map_files/%lx-100000000%lx", a, b); } else if (sizeof(long) == 8) { fail("/proc/self/map_files/10000000000000000%lx-%lx", a, b); fail("/proc/self/map_files/%lx-10000000000000000%lx", a, b); } else return 1; return 0; }