tests/tcg/test-mmap.c - qemu - Git at Google

 /*
  * Small test program to verify simulated mmap behaviour.
  *
  * When running qemu-linux-user with the -p flag, you may need to tell
  * this test program about the pagesize because getpagesize() will not reflect
  * the -p choice. Simply pass one argument being the pagesize.
  *
  * Copyright (c) 2007 AXIS Communications AB
  * Written by Edgar E. Iglesias.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */

 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
 #include <unistd.h>

 #include <sys/mman.h>

 #define D(x)

 #define fail_unless(x)                                         \
 do                                                             \
 {                                                              \
   if (!(x)) {                                                  \
     fprintf (stderr, "FAILED at %s:%d\n", __FILE__, __LINE__); \
     exit (EXIT_FAILURE);                                       \
   }                                                            \
 } while (0);

 unsigned char *dummybuf;
 static unsigned int pagesize;
 static unsigned int pagemask;
 int test_fd;
 size_t test_fsize;

 void check_aligned_anonymous_unfixed_mmaps(void)
 {
 	void *p1;
 	void *p2;
 	void *p3;
 	void *p4;
 	void *p5;
 	uintptr_t p;
 	int i;

 	fprintf (stderr, "%s", __func__);
 	for (i = 0; i < 0x1fff; i++)
 	{
 		size_t len;

 		len = pagesize + (pagesize * i & 7);
 		p1 = mmap(NULL, len, PROT_READ,
 			  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		p2 = mmap(NULL, len, PROT_READ,
 			  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		p3 = mmap(NULL, len, PROT_READ,
 			  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		p4 = mmap(NULL, len, PROT_READ,
 			  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		p5 = mmap(NULL, len, PROT_READ,
 			  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

 		/* Make sure we get pages aligned with the pagesize. The
 		   target expects this.  */
 		fail_unless (p1 != MAP_FAILED);
 		fail_unless (p2 != MAP_FAILED);
 		fail_unless (p3 != MAP_FAILED);
 		fail_unless (p4 != MAP_FAILED);
 		fail_unless (p5 != MAP_FAILED);
 		p = (uintptr_t) p1;
 		D(printf ("p=%x\n", p));
 		fail_unless ((p & pagemask) == 0);
 		p = (uintptr_t) p2;
 		fail_unless ((p & pagemask) == 0);
 		p = (uintptr_t) p3;
 		fail_unless ((p & pagemask) == 0);
 		p = (uintptr_t) p4;
 		fail_unless ((p & pagemask) == 0);
 		p = (uintptr_t) p5;
 		fail_unless ((p & pagemask) == 0);

 		/* Make sure we can read from the entire area.  */
 		memcpy (dummybuf, p1, pagesize);
 		memcpy (dummybuf, p2, pagesize);
 		memcpy (dummybuf, p3, pagesize);
 		memcpy (dummybuf, p4, pagesize);
 		memcpy (dummybuf, p5, pagesize);

 		munmap (p1, len);
 		munmap (p2, len);
 		munmap (p3, len);
 		munmap (p4, len);
 		munmap (p5, len);
 	}
 	fprintf (stderr, " passed\n");
 }

 void check_large_anonymous_unfixed_mmap(void)
 {
 	void *p1;
 	uintptr_t p;
 	size_t len;

 	fprintf (stderr, "%s", __func__);

 	len = 0x02000000;
 	p1 = mmap(NULL, len, PROT_READ,
 		  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

 	/* Make sure we get pages aligned with the pagesize. The
 	   target expects this.  */
 	fail_unless (p1 != MAP_FAILED);
 	p = (uintptr_t) p1;
 	fail_unless ((p & pagemask) == 0);

 	/* Make sure we can read from the entire area.  */
 	memcpy (dummybuf, p1, pagesize);
 	munmap (p1, len);
 	fprintf (stderr, " passed\n");
 }

 void check_aligned_anonymous_unfixed_colliding_mmaps(void)
 {
 	char *p1;
 	char *p2;
 	char *p3;
 	uintptr_t p;
 	int i;

 	fprintf (stderr, "%s", __func__);
 	for (i = 0; i < 0x2fff; i++)
 	{
 		int nlen;
 		p1 = mmap(NULL, pagesize, PROT_READ,
 			  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		fail_unless (p1 != MAP_FAILED);
 		p = (uintptr_t) p1;
 		fail_unless ((p & pagemask) == 0);
 		memcpy (dummybuf, p1, pagesize);

 		p2 = mmap(NULL, pagesize, PROT_READ,
 			  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		fail_unless (p2 != MAP_FAILED);
 		p = (uintptr_t) p2;
 		fail_unless ((p & pagemask) == 0);
 		memcpy (dummybuf, p2, pagesize);


 		munmap (p1, pagesize);
 		nlen = pagesize * 8;
 		p3 = mmap(NULL, nlen, PROT_READ,
 			  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 		fail_unless (p3 != MAP_FAILED);

 		/* Check if the mmaped areas collide.  */
 		if (p3 < p2
 		    && (p3 + nlen) > p2)
 			fail_unless (0);

 		memcpy (dummybuf, p3, pagesize);

 		/* Make sure we get pages aligned with the pagesize. The
 		   target expects this.  */
 		p = (uintptr_t) p3;
 		fail_unless ((p & pagemask) == 0);
 		munmap (p2, pagesize);
 		munmap (p3, nlen);
 	}
 	fprintf (stderr, " passed\n");
 }

 void check_aligned_anonymous_fixed_mmaps(void)
 {
 	char *addr;
 	void *p1;
 	uintptr_t p;
 	int i;

 	/* Find a suitable address to start with.  */
 	addr = mmap(NULL, pagesize * 40, PROT_READ | PROT_WRITE,
 		    MAP_PRIVATE | MAP_ANONYMOUS,
 		    -1, 0);
 	fprintf (stderr, "%s addr=%p", __func__, addr);
 	fail_unless (addr != MAP_FAILED);

 	for (i = 0; i < 40; i++)
 	{
 		/* Create submaps within our unfixed map.  */
 		p1 = mmap(addr, pagesize, PROT_READ,
 			  MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
 			  -1, 0);
 		/* Make sure we get pages aligned with the pagesize.
 		   The target expects this.  */
 		p = (uintptr_t) p1;
 		fail_unless (p1 == addr);
 		fail_unless ((p & pagemask) == 0);
 		memcpy (dummybuf, p1, pagesize);
 		munmap (p1, pagesize);
 		addr += pagesize;
 	}
 	fprintf (stderr, " passed\n");
 }

 void check_aligned_anonymous_fixed_mmaps_collide_with_host(void)
 {
 	char *addr;
 	void *p1;
 	uintptr_t p;
 	int i;

 	/* Find a suitable address to start with.  Right were the x86 hosts
 	 stack is.  */
 	addr = ((void *)0x80000000);
 	fprintf (stderr, "%s addr=%p", __func__, addr);
 	fprintf (stderr, "FIXME: QEMU fails to track pages used by the host.");

 	for (i = 0; i < 20; i++)
 	{
 		/* Create submaps within our unfixed map.  */
 		p1 = mmap(addr, pagesize, PROT_READ | PROT_WRITE,
 			  MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED,
 			  -1, 0);
 		/* Make sure we get pages aligned with the pagesize.
 		   The target expects this.  */
 		p = (uintptr_t) p1;
 		fail_unless (p1 == addr);
 		fail_unless ((p & pagemask) == 0);
 		memcpy (p1, dummybuf, pagesize);
 		munmap (p1, pagesize);
 		addr += pagesize;
 	}
 	fprintf (stderr, " passed\n");
 }

 void check_file_unfixed_mmaps(void)
 {
 	unsigned int *p1, *p2, *p3;
 	uintptr_t p;
 	int i;

 	fprintf (stderr, "%s", __func__);
 	for (i = 0; i < 0x10; i++)
 	{
 		size_t len;

 		len = pagesize;
 		p1 = mmap(NULL, len, PROT_READ,
 			  MAP_PRIVATE,
 			  test_fd, 0);
 		p2 = mmap(NULL, len, PROT_READ,
 			  MAP_PRIVATE,
 			  test_fd, pagesize);
 		p3 = mmap(NULL, len, PROT_READ,
 			  MAP_PRIVATE,
 			  test_fd, pagesize * 2);

 		fail_unless (p1 != MAP_FAILED);
 		fail_unless (p2 != MAP_FAILED);
 		fail_unless (p3 != MAP_FAILED);

 		/* Make sure we get pages aligned with the pagesize. The
 		   target expects this.  */
 		p = (uintptr_t) p1;
 		fail_unless ((p & pagemask) == 0);
 		p = (uintptr_t) p2;
 		fail_unless ((p & pagemask) == 0);
 		p = (uintptr_t) p3;
 		fail_unless ((p & pagemask) == 0);

 		/* Verify that the file maps was made correctly.  */
 		D(printf ("p1=%d p2=%d p3=%d\n", *p1, *p2, *p3));
 		fail_unless (*p1 == 0);
 		fail_unless (*p2 == (pagesize / sizeof *p2));
 		fail_unless (*p3 == ((pagesize * 2) / sizeof *p3));

 		memcpy (dummybuf, p1, pagesize);
 		memcpy (dummybuf, p2, pagesize);
 		memcpy (dummybuf, p3, pagesize);
 		munmap (p1, len);
 		munmap (p2, len);
 		munmap (p3, len);
 	}
 	fprintf (stderr, " passed\n");
 }

 void check_file_unfixed_eof_mmaps(void)
 {
 	char *cp;
 	unsigned int *p1;
 	uintptr_t p;
 	int i;

 	fprintf (stderr, "%s", __func__);
 	for (i = 0; i < 0x10; i++)
 	{
 		p1 = mmap(NULL, pagesize, PROT_READ,
 			  MAP_PRIVATE,
 			  test_fd,
 			  (test_fsize - sizeof *p1) & ~pagemask);

 		fail_unless (p1 != MAP_FAILED);

 		/* Make sure we get pages aligned with the pagesize. The
 		   target expects this.  */
 		p = (uintptr_t) p1;
 		fail_unless ((p & pagemask) == 0);
 		/* Verify that the file maps was made correctly.  */
 		fail_unless (p1[(test_fsize & pagemask) / sizeof *p1 - 1]
 			     == ((test_fsize - sizeof *p1) / sizeof *p1));

 		/* Verify that the end of page is accessible and zeroed.  */
 		cp = (void *) p1;
 		fail_unless (cp[pagesize - 4] == 0);
 		munmap (p1, pagesize);
 	}
 	fprintf (stderr, " passed\n");
 }

 void check_file_fixed_eof_mmaps(void)
 {
 	char *addr;
 	char *cp;
 	unsigned int *p1;
 	uintptr_t p;
 	int i;

 	/* Find a suitable address to start with.  */
 	addr = mmap(NULL, pagesize * 44, PROT_READ,
 		    MAP_PRIVATE | MAP_ANONYMOUS,
 		    -1, 0);

 	fprintf (stderr, "%s addr=%p", __func__, (void *)addr);
 	fail_unless (addr != MAP_FAILED);

 	for (i = 0; i < 0x10; i++)
 	{
 		/* Create submaps within our unfixed map.  */
 		p1 = mmap(addr, pagesize, PROT_READ,
 			  MAP_PRIVATE | MAP_FIXED,
 			  test_fd,
 			  (test_fsize - sizeof *p1) & ~pagemask);

 		fail_unless (p1 != MAP_FAILED);

 		/* Make sure we get pages aligned with the pagesize. The
 		   target expects this.  */
 		p = (uintptr_t) p1;
 		fail_unless ((p & pagemask) == 0);

 		/* Verify that the file maps was made correctly.  */
 		fail_unless (p1[(test_fsize & pagemask) / sizeof *p1 - 1]
 			     == ((test_fsize - sizeof *p1) / sizeof *p1));

 		/* Verify that the end of page is accessible and zeroed.  */
 		cp = (void *)p1;
 		fail_unless (cp[pagesize - 4] == 0);
 		munmap (p1, pagesize);
 		addr += pagesize;
 	}
 	fprintf (stderr, " passed\n");
 }

 void check_file_fixed_mmaps(void)
 {
 	unsigned char *addr;
 	unsigned int *p1, *p2, *p3, *p4;
 	int i;

 	/* Find a suitable address to start with.  */
 	addr = mmap(NULL, pagesize * 40 * 4, PROT_READ,
 		    MAP_PRIVATE | MAP_ANONYMOUS,
 		    -1, 0);
 	fprintf (stderr, "%s addr=%p", __func__, (void *)addr);
 	fail_unless (addr != MAP_FAILED);

 	for (i = 0; i < 40; i++)
 	{
 		p1 = mmap(addr, pagesize, PROT_READ,
 			  MAP_PRIVATE | MAP_FIXED,
 			  test_fd, 0);
 		p2 = mmap(addr + pagesize, pagesize, PROT_READ,
 			  MAP_PRIVATE | MAP_FIXED,
 			  test_fd, pagesize);
 		p3 = mmap(addr + pagesize * 2, pagesize, PROT_READ,
 			  MAP_PRIVATE | MAP_FIXED,
 			  test_fd, pagesize * 2);
 		p4 = mmap(addr + pagesize * 3, pagesize, PROT_READ,
 			  MAP_PRIVATE | MAP_FIXED,
 			  test_fd, pagesize * 3);

 		/* Make sure we get pages aligned with the pagesize.
 		   The target expects this.  */
 		fail_unless (p1 == (void *)addr);
 		fail_unless (p2 == (void *)addr + pagesize);
 		fail_unless (p3 == (void *)addr + pagesize * 2);
 		fail_unless (p4 == (void *)addr + pagesize * 3);

 		/* Verify that the file maps was made correctly.  */
 		fail_unless (*p1 == 0);
 		fail_unless (*p2 == (pagesize / sizeof *p2));
 		fail_unless (*p3 == ((pagesize * 2) / sizeof *p3));
 		fail_unless (*p4 == ((pagesize * 3) / sizeof *p4));

 		memcpy (dummybuf, p1, pagesize);
 		memcpy (dummybuf, p2, pagesize);
 		memcpy (dummybuf, p3, pagesize);
 		memcpy (dummybuf, p4, pagesize);

 		munmap (p1, pagesize);
 		munmap (p2, pagesize);
 		munmap (p3, pagesize);
 		munmap (p4, pagesize);
 		addr += pagesize * 4;
 	}
 	fprintf (stderr, " passed\n");
 }

 int main(int argc, char **argv)
 {
 	char tempname[] = "/tmp/.cmmapXXXXXX";
 	unsigned int i;

 	/* Trust the first argument, otherwise probe the system for our
 	   pagesize.  */
 	if (argc > 1)
 		pagesize = strtoul(argv[1], NULL, 0);
 	else
 		pagesize = sysconf(_SC_PAGESIZE);

 	/* Assume pagesize is a power of two.  */
 	pagemask = pagesize - 1;
 	dummybuf = malloc (pagesize);
 	printf ("pagesize=%u pagemask=%x\n", pagesize, pagemask);

 	test_fd = mkstemp(tempname);
 	unlink(tempname);

 	/* Fill the file with int's counting from zero and up.  */
 	for (i = 0; i < (pagesize * 4) / sizeof i; i++)
 		write (test_fd, &i, sizeof i);
 	/* Append a few extra writes to make the file end at non
 	   page boundary.  */
 	write (test_fd, &i, sizeof i); i++;
 	write (test_fd, &i, sizeof i); i++;
 	write (test_fd, &i, sizeof i); i++;

 	test_fsize = lseek(test_fd, 0, SEEK_CUR);

 	/* Run the tests.  */
 	check_aligned_anonymous_unfixed_mmaps();
 	check_aligned_anonymous_unfixed_colliding_mmaps();
 	check_aligned_anonymous_fixed_mmaps();
 	check_file_unfixed_mmaps();
 	check_file_fixed_mmaps();
 	check_file_fixed_eof_mmaps();
 	check_file_unfixed_eof_mmaps();

 	/* Fails at the moment.  */
 	/* check_aligned_anonymous_fixed_mmaps_collide_with_host(); */

 	return EXIT_SUCCESS;
 }
	/*
	* Small test program to verify simulated mmap behaviour.
	*
	* When running qemu-linux-user with the -p flag, you may need to tell
	* this test program about the pagesize because getpagesize() will not reflect
	* the -p choice. Simply pass one argument being the pagesize.
	*
	* Copyright (c) 2007 AXIS Communications AB
	* Written by Edgar E. Iglesias.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see <http://www.gnu.org/licenses/>.
	*/

	#include <stdio.h>
	#include <stdlib.h>
	#include <stdint.h>
	#include <string.h>
	#include <unistd.h>

	#include <sys/mman.h>

	#define D(x)

	#define fail_unless(x) \
	do \
	{ \
	if (!(x)) { \
	fprintf (stderr, "FAILED at %s:%d\n", __FILE__, __LINE__); \
	exit (EXIT_FAILURE); \
	} \
	} while (0);

	unsigned char *dummybuf;
	static unsigned int pagesize;
	static unsigned int pagemask;
	int test_fd;
	size_t test_fsize;

	void check_aligned_anonymous_unfixed_mmaps(void)
	{
	void *p1;
	void *p2;
	void *p3;
	void *p4;
	void *p5;
	uintptr_t p;
	int i;

	fprintf (stderr, "%s", __func__);
	for (i = 0; i < 0x1fff; i++)
	{
	size_t len;

	len = pagesize + (pagesize * i & 7);
	p1 = mmap(NULL, len, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
	p2 = mmap(NULL, len, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
	p3 = mmap(NULL, len, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
	p4 = mmap(NULL, len, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
	p5 = mmap(NULL, len, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);

	/* Make sure we get pages aligned with the pagesize. The
	target expects this. */
	fail_unless (p1 != MAP_FAILED);
	fail_unless (p2 != MAP_FAILED);
	fail_unless (p3 != MAP_FAILED);
	fail_unless (p4 != MAP_FAILED);
	fail_unless (p5 != MAP_FAILED);
	p = (uintptr_t) p1;
	D(printf ("p=%x\n", p));
	fail_unless ((p & pagemask) == 0);
	p = (uintptr_t) p2;
	fail_unless ((p & pagemask) == 0);
	p = (uintptr_t) p3;
	fail_unless ((p & pagemask) == 0);
	p = (uintptr_t) p4;
	fail_unless ((p & pagemask) == 0);
	p = (uintptr_t) p5;
	fail_unless ((p & pagemask) == 0);

	/* Make sure we can read from the entire area. */
	memcpy (dummybuf, p1, pagesize);
	memcpy (dummybuf, p2, pagesize);
	memcpy (dummybuf, p3, pagesize);
	memcpy (dummybuf, p4, pagesize);
	memcpy (dummybuf, p5, pagesize);

	munmap (p1, len);
	munmap (p2, len);
	munmap (p3, len);
	munmap (p4, len);
	munmap (p5, len);
	}
	fprintf (stderr, " passed\n");
	}

	void check_large_anonymous_unfixed_mmap(void)
	{
	void *p1;
	uintptr_t p;
	size_t len;

	fprintf (stderr, "%s", __func__);

	len = 0x02000000;
	p1 = mmap(NULL, len, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);

	/* Make sure we get pages aligned with the pagesize. The
	target expects this. */
	fail_unless (p1 != MAP_FAILED);
	p = (uintptr_t) p1;
	fail_unless ((p & pagemask) == 0);

	/* Make sure we can read from the entire area. */
	memcpy (dummybuf, p1, pagesize);
	munmap (p1, len);
	fprintf (stderr, " passed\n");
	}

	void check_aligned_anonymous_unfixed_colliding_mmaps(void)
	{
	char *p1;
	char *p2;
	char *p3;
	uintptr_t p;
	int i;

	fprintf (stderr, "%s", __func__);
	for (i = 0; i < 0x2fff; i++)
	{
	int nlen;
	p1 = mmap(NULL, pagesize, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
	fail_unless (p1 != MAP_FAILED);
	p = (uintptr_t) p1;
	fail_unless ((p & pagemask) == 0);
	memcpy (dummybuf, p1, pagesize);

	p2 = mmap(NULL, pagesize, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
	fail_unless (p2 != MAP_FAILED);
	p = (uintptr_t) p2;
	fail_unless ((p & pagemask) == 0);
	memcpy (dummybuf, p2, pagesize);


	munmap (p1, pagesize);
	nlen = pagesize * 8;
	p3 = mmap(NULL, nlen, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
	fail_unless (p3 != MAP_FAILED);

	/* Check if the mmaped areas collide. */
	if (p3 < p2
	&& (p3 + nlen) > p2)
	fail_unless (0);

	memcpy (dummybuf, p3, pagesize);

	/* Make sure we get pages aligned with the pagesize. The
	target expects this. */
	p = (uintptr_t) p3;
	fail_unless ((p & pagemask) == 0);
	munmap (p2, pagesize);
	munmap (p3, nlen);
	}
	fprintf (stderr, " passed\n");
	}

	void check_aligned_anonymous_fixed_mmaps(void)
	{
	char *addr;
	void *p1;
	uintptr_t p;
	int i;

	/* Find a suitable address to start with. */
	addr = mmap(NULL, pagesize * 40, PROT_READ \| PROT_WRITE,
	MAP_PRIVATE \| MAP_ANONYMOUS,
	-1, 0);
	fprintf (stderr, "%s addr=%p", __func__, addr);
	fail_unless (addr != MAP_FAILED);

	for (i = 0; i < 40; i++)
	{
	/* Create submaps within our unfixed map. */
	p1 = mmap(addr, pagesize, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS \| MAP_FIXED,
	-1, 0);
	/* Make sure we get pages aligned with the pagesize.
	The target expects this. */
	p = (uintptr_t) p1;
	fail_unless (p1 == addr);
	fail_unless ((p & pagemask) == 0);
	memcpy (dummybuf, p1, pagesize);
	munmap (p1, pagesize);
	addr += pagesize;
	}
	fprintf (stderr, " passed\n");
	}

	void check_aligned_anonymous_fixed_mmaps_collide_with_host(void)
	{
	char *addr;
	void *p1;
	uintptr_t p;
	int i;

	/* Find a suitable address to start with. Right were the x86 hosts
	stack is. */
	addr = ((void *)0x80000000);
	fprintf (stderr, "%s addr=%p", __func__, addr);
	fprintf (stderr, "FIXME: QEMU fails to track pages used by the host.");

	for (i = 0; i < 20; i++)
	{
	/* Create submaps within our unfixed map. */
	p1 = mmap(addr, pagesize, PROT_READ \| PROT_WRITE,
	MAP_PRIVATE \| MAP_ANONYMOUS \| MAP_FIXED,
	-1, 0);
	/* Make sure we get pages aligned with the pagesize.
	The target expects this. */
	p = (uintptr_t) p1;
	fail_unless (p1 == addr);
	fail_unless ((p & pagemask) == 0);
	memcpy (p1, dummybuf, pagesize);
	munmap (p1, pagesize);
	addr += pagesize;
	}
	fprintf (stderr, " passed\n");
	}

	void check_file_unfixed_mmaps(void)
	{
	unsigned int p1, p2, *p3;
	uintptr_t p;
	int i;

	fprintf (stderr, "%s", __func__);
	for (i = 0; i < 0x10; i++)
	{
	size_t len;

	len = pagesize;
	p1 = mmap(NULL, len, PROT_READ,
	MAP_PRIVATE,
	test_fd, 0);
	p2 = mmap(NULL, len, PROT_READ,
	MAP_PRIVATE,
	test_fd, pagesize);
	p3 = mmap(NULL, len, PROT_READ,
	MAP_PRIVATE,
	test_fd, pagesize * 2);

	fail_unless (p1 != MAP_FAILED);
	fail_unless (p2 != MAP_FAILED);
	fail_unless (p3 != MAP_FAILED);

	/* Make sure we get pages aligned with the pagesize. The
	target expects this. */
	p = (uintptr_t) p1;
	fail_unless ((p & pagemask) == 0);
	p = (uintptr_t) p2;
	fail_unless ((p & pagemask) == 0);
	p = (uintptr_t) p3;
	fail_unless ((p & pagemask) == 0);

	/* Verify that the file maps was made correctly. */
	D(printf ("p1=%d p2=%d p3=%d\n", p1, p2, *p3));
	fail_unless (*p1 == 0);
	fail_unless (p2 == (pagesize / sizeof p2));
	fail_unless (p3 == ((pagesize 2) / sizeof *p3));

	memcpy (dummybuf, p1, pagesize);
	memcpy (dummybuf, p2, pagesize);
	memcpy (dummybuf, p3, pagesize);
	munmap (p1, len);
	munmap (p2, len);
	munmap (p3, len);
	}
	fprintf (stderr, " passed\n");
	}

	void check_file_unfixed_eof_mmaps(void)
	{
	char *cp;
	unsigned int *p1;
	uintptr_t p;
	int i;

	fprintf (stderr, "%s", __func__);
	for (i = 0; i < 0x10; i++)
	{
	p1 = mmap(NULL, pagesize, PROT_READ,
	MAP_PRIVATE,
	test_fd,
	(test_fsize - sizeof *p1) & ~pagemask);

	fail_unless (p1 != MAP_FAILED);

	/* Make sure we get pages aligned with the pagesize. The
	target expects this. */
	p = (uintptr_t) p1;
	fail_unless ((p & pagemask) == 0);
	/* Verify that the file maps was made correctly. */
	fail_unless (p1[(test_fsize & pagemask) / sizeof *p1 - 1]
	== ((test_fsize - sizeof p1) / sizeof p1));

	/* Verify that the end of page is accessible and zeroed. */
	cp = (void *) p1;
	fail_unless (cp[pagesize - 4] == 0);
	munmap (p1, pagesize);
	}
	fprintf (stderr, " passed\n");
	}

	void check_file_fixed_eof_mmaps(void)
	{
	char *addr;
	char *cp;
	unsigned int *p1;
	uintptr_t p;
	int i;

	/* Find a suitable address to start with. */
	addr = mmap(NULL, pagesize * 44, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS,
	-1, 0);

	fprintf (stderr, "%s addr=%p", __func__, (void *)addr);
	fail_unless (addr != MAP_FAILED);

	for (i = 0; i < 0x10; i++)
	{
	/* Create submaps within our unfixed map. */
	p1 = mmap(addr, pagesize, PROT_READ,
	MAP_PRIVATE \| MAP_FIXED,
	test_fd,
	(test_fsize - sizeof *p1) & ~pagemask);

	fail_unless (p1 != MAP_FAILED);

	/* Make sure we get pages aligned with the pagesize. The
	target expects this. */
	p = (uintptr_t) p1;
	fail_unless ((p & pagemask) == 0);

	/* Verify that the file maps was made correctly. */
	fail_unless (p1[(test_fsize & pagemask) / sizeof *p1 - 1]
	== ((test_fsize - sizeof p1) / sizeof p1));

	/* Verify that the end of page is accessible and zeroed. */
	cp = (void *)p1;
	fail_unless (cp[pagesize - 4] == 0);
	munmap (p1, pagesize);
	addr += pagesize;
	}
	fprintf (stderr, " passed\n");
	}

	void check_file_fixed_mmaps(void)
	{
	unsigned char *addr;
	unsigned int p1, p2, p3, p4;
	int i;

	/* Find a suitable address to start with. */
	addr = mmap(NULL, pagesize * 40 * 4, PROT_READ,
	MAP_PRIVATE \| MAP_ANONYMOUS,
	-1, 0);
	fprintf (stderr, "%s addr=%p", __func__, (void *)addr);
	fail_unless (addr != MAP_FAILED);

	for (i = 0; i < 40; i++)
	{
	p1 = mmap(addr, pagesize, PROT_READ,
	MAP_PRIVATE \| MAP_FIXED,
	test_fd, 0);
	p2 = mmap(addr + pagesize, pagesize, PROT_READ,
	MAP_PRIVATE \| MAP_FIXED,
	test_fd, pagesize);
	p3 = mmap(addr + pagesize * 2, pagesize, PROT_READ,
	MAP_PRIVATE \| MAP_FIXED,
	test_fd, pagesize * 2);
	p4 = mmap(addr + pagesize * 3, pagesize, PROT_READ,
	MAP_PRIVATE \| MAP_FIXED,
	test_fd, pagesize * 3);

	/* Make sure we get pages aligned with the pagesize.
	The target expects this. */
	fail_unless (p1 == (void *)addr);
	fail_unless (p2 == (void *)addr + pagesize);
	fail_unless (p3 == (void )addr + pagesize 2);
	fail_unless (p4 == (void )addr + pagesize 3);

	/* Verify that the file maps was made correctly. */
	fail_unless (*p1 == 0);
	fail_unless (p2 == (pagesize / sizeof p2));
	fail_unless (p3 == ((pagesize 2) / sizeof *p3));
	fail_unless (p4 == ((pagesize 3) / sizeof *p4));

	memcpy (dummybuf, p1, pagesize);
	memcpy (dummybuf, p2, pagesize);
	memcpy (dummybuf, p3, pagesize);
	memcpy (dummybuf, p4, pagesize);

	munmap (p1, pagesize);
	munmap (p2, pagesize);
	munmap (p3, pagesize);
	munmap (p4, pagesize);
	addr += pagesize * 4;
	}
	fprintf (stderr, " passed\n");
	}

	int main(int argc, char **argv)
	{
	char tempname[] = "/tmp/.cmmapXXXXXX";
	unsigned int i;

	/* Trust the first argument, otherwise probe the system for our
	pagesize. */
	if (argc > 1)
	pagesize = strtoul(argv[1], NULL, 0);
	else
	pagesize = sysconf(_SC_PAGESIZE);

	/* Assume pagesize is a power of two. */
	pagemask = pagesize - 1;
	dummybuf = malloc (pagesize);
	printf ("pagesize=%u pagemask=%x\n", pagesize, pagemask);

	test_fd = mkstemp(tempname);
	unlink(tempname);

	/* Fill the file with int's counting from zero and up. */
	for (i = 0; i < (pagesize * 4) / sizeof i; i++)
	write (test_fd, &i, sizeof i);
	/* Append a few extra writes to make the file end at non
	page boundary. */
	write (test_fd, &i, sizeof i); i++;
	write (test_fd, &i, sizeof i); i++;
	write (test_fd, &i, sizeof i); i++;

	test_fsize = lseek(test_fd, 0, SEEK_CUR);

	/* Run the tests. */
	check_aligned_anonymous_unfixed_mmaps();
	check_aligned_anonymous_unfixed_colliding_mmaps();
	check_aligned_anonymous_fixed_mmaps();
	check_file_unfixed_mmaps();
	check_file_fixed_mmaps();
	check_file_fixed_eof_mmaps();
	check_file_unfixed_eof_mmaps();

	/* Fails at the moment. */
	/* check_aligned_anonymous_fixed_mmaps_collide_with_host(); */

	return EXIT_SUCCESS;
	}