/* * Copyright (c) 2013 * The President and Fellows of Harvard College. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * zero - check that the VM system zeros pages given to processes * * This program will be much more likely to detect a problem if you * run it *after* one of the out-of-core tests (huge, matmult, sort, * etc.) */ #include <stdio.h> #include <unistd.h> #include <errno.h> #include <err.h> /* * Some initialized data. This is here to increase the chance that * zeros[] spans page boundaries. */ static unsigned data_stuff[] = { 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, 2, 4, 6, 8, 0, }; #define SUM_OF_DATA_STUFF 525 /* * Some uninitialized (BSS, zero) data. Make it more than one page * even if we happen to be on a machine with 8K pages. */ static unsigned bss_stuff[3000]; static void check_data(void) { unsigned i, num, k; num = sizeof(data_stuff) / sizeof(data_stuff[0]); for (k=i=0; i<num; i++) { k += data_stuff[i]; } if (k != SUM_OF_DATA_STUFF) { warnx("My initialized data sums to the wrong value!"); warnx("Got: %u Expected: %u", k, SUM_OF_DATA_STUFF); errx(1, "FAILED"); } } static void check_bss(void) { unsigned i, num; num = sizeof(bss_stuff) / sizeof(bss_stuff[0]); for (i=0; i<num; i++) { if (bss_stuff[i] != 0) { warnx("BSS entry at index %u (address %p) not zero!", i, &bss_stuff[i]); warnx("Found: 0x%x", bss_stuff[i]); errx(1, "FAILED"); } } } static void check_sbrk(void) { char *base; unsigned i; /* get at least one page, even if the page size is 8K */ #define SBRK_SIZE 8192 base = sbrk(SBRK_SIZE); if (base == (void *)-1) { if (errno == ENOSYS) { printf("I guess you haven't implemented sbrk yet.\n"); return; } err(1, "sbrk"); } for (i=0; i<SBRK_SIZE; i++) { if (base[i] != 0) { warnx("Byte at offset %u (address %p) not zero", i, &base[i]); warnx("Got: 0x%x", (unsigned char)base[i]); warnx("Base of sbrk region: %p", base); errx(1, "FAILED"); } } } int main(void) { printf("zero: phase 1: checking .bss\n"); check_data(); check_bss(); printf("zero: phase 2: checking sbrk()\n"); check_sbrk(); printf("zero: passed\n"); return 0; }