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Here is the mmap() tested I mentioned recently

To: zmailer@nic.funet.fi
Subject: Here is the mmap() tested I mentioned recently
From: mea@utu.fi
Date: Mon, 19 Aug 1996 21:51:06 +0300
Sender: Matti E Aarnio <mea@mea.utu.fi>

>From owner-linux-kernel-outgoing@vger.rutgers.edu  Mon Aug 12 22:14:25 1996
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To:	linux-kernel@vger.rutgers.edu
Subject: Julian Assange: mmap test program
Date:	Sat, 10 Aug 1996 22:56:54 -0600
From:	Warner Losh <imp@village.org>
Sender: owner-linux-kernel@vger.rutgers.edu
Precedence: bulk
Status: RO

Julian Assange just posted this to -hackers.  Since I've not seen it
come in on linux-kernel, I thought I'd post it here for those people
that are hacking on the Linux VM system.  It would appear from the
comments that there are a few flaws in the Linux VM system when it
comes to completely implementing mmap semantics that the author of
this program tests for.  I have not tried it on a Linux machine, but
since Julian Assange shows a smaller list for Linux than for FreeBSD
in his comments, I thought the Linux folks would like to know.

I present this in the hope that it is a useful tool for the potential
betterment of Linux.  Please do not take it as flame bate, or one of
those horrible "My Daddy's OS can beat up your Daddy's OS, so
nanananana" threads that crop up from time to time.

Warner

P.S.  My appologies if this is the 1000th forward of this that you've
seen today.  I did check first :-)

------- Forwarded Message

[[ Headers editted ]]
From: Julian Assange <proff@suburbia.net>
Message-Id: <199608102124.HAA15697@suburbia.net>
Subject: mmap
To: freebsd-hackers@FreeBSD.ORG
Date: Sun, 11 Aug 1996 07:24:22 +1000 (EST)


Recently I wrote some mmap() testing routines for GNU autoconf, you
may be pleased to know that FreeBSD mmap seems faultless.

I'd be interested in seeing results from other platforms....


/* $Id: mmap_tests.c,v 1.1 1996/08/10 20:12:09 proff Exp $
 * 
 * various mmap() immplimentations suck, we attempt to find out just how
 * hard.
 *
 *        - Julian Assange (proff@suburbia.net)
 *
 * Test results: (please send additions to proff@suburbia.net)
 *
 *   Linux suburbia 2.0.0 #29- Thu Jul 11 18:03:20 EST 1996 i586 
 *
 *	HAVE_MMAP_FILE_PRIVATE_READ
 *	HAVE_MMAP_FILE_PRIVATE_CHILD_INHERIT
 *	HAVE_MMAP_FILE_PRIVATE_WRITE
 *	HAVE_MMAP_FILE_SHARED_READ
 *	HAVE_MMAP_FILE_SHARED_CHILD_INHERIT
 *	HAVE_MMAP_FILE_SHARED_CHILD_READ_PARENT_WRITE
 *	HAVE_MMAP_FILE_SHARED_PARENT_READ_CHILD_WRITE
 *	HAVE_MMAP_FILE_SHARED_WRITE
 *	HAVE_MMAP_DEV_ZERO_PRIVATE
 *	HAVE_MMAP_DEV_ZERO_PRIVATE_CHILD_INHERIT
 *	HAVE_MMAP_ANON_PRIVATE
 *	HAVE_MMAP_ANON_PRIVATE_CHILD_INHERIT
 *
 *   FreeBSD profane 2.2-CURRENT #0 Sat Jul 27 19:16:00 EST 1996
 *
 *	HAVE_MMAP_FILE_PRIVATE_READ
 *	HAVE_MMAP_FILE_PRIVATE_CHILD_INHERIT
 *	HAVE_MMAP_FILE_PRIVATE_WRITE
 *	HAVE_MMAP_FILE_SHARED_READ
 *	HAVE_MMAP_FILE_SHARED_CHILD_INHERIT
 *	HAVE_MMAP_FILE_SHARED_CHILD_READ_PARENT_WRITE
 *	HAVE_MMAP_FILE_SHARED_PARENT_READ_CHILD_WRITE
 *	HAVE_MMAP_FILE_SHARED_WRITE
 *	HAVE_MMAP_DEV_ZERO_PRIVATE
 *	HAVE_MMAP_DEV_ZERO_PRIVATE_CHILD_INHERIT
 *	HAVE_MMAP_DEV_ZERO_SHARED
 *	HAVE_MMAP_DEV_ZERO_SHARED_CHILD_INHERIT
 *	HAVE_MMAP_DEV_ZERO_SHARED_CHILD_READ_PARENT_WRITE
 *	HAVE_MMAP_DEV_ZERO_SHARED_PARENT_READ_CHILD_WRITE
 *	HAVE_MMAP_ANON_PRIVATE
 *	HAVE_MMAP_ANON_PRIVATE_CHILD_INHERIT
 *	HAVE_MMAP_ANON_SHARED
 *	HAVE_MMAP_ANON_SHARED_CHILD_INHERIT
 *	HAVE_MMAP_ANON_SHARED_CHILD_READ_PARENT_WRITE
 *	HAVE_MMAP_ANON_SHARED_PARENT_READ_CHILD_WRITE
 */

#include <stdio.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>

#define MM_SIZE (100*1024)
#define TEST_FILE "mmap.test"

int caught_sigint;

void sigint (int sig)
{
	caught_sigint++;
	signal (SIGINT, sigint);
}

/* 
 * TODO: test MAP_INHERIT, MAP_FIXED  (can't see that latter being much of an issue)
 */

void
test_child(char *p, char *msg)
{
	char *im = "inherit_magic";
	char *pm = "parent_magic";
	char *cm = "child_magic";
	pid_t pid;
	strcpy (p, im);
	caught_sigint = 0;
	signal (SIGINT, sigint);
	fflush (stdout);
	pid = fork();
	if (pid<0)
		return;
	if (pid==0)
	{
		if (strcmp(p, im)==0)
			printf("%s_CHILD_INHERIT\n", msg);
		kill (getppid(), SIGINT);
		while (!caught_sigint)
			pause ();
		caught_sigint = 0;
		if (strcmp(p, pm)==0)
			printf("%s_CHILD_READ_PARENT_WRITE\n", msg);
		strcpy (p, cm);
		fflush (stdout);
		kill (getppid(), SIGINT);
		exit(0);
	}
	/* parent */
	while (!caught_sigint)
		pause ();
	caught_sigint = 0;
	strcpy (p, pm);
	kill (pid, SIGINT);
	while (!caught_sigint)
		pause ();
	if (strcmp(p, cm)==0)
		printf("%s_PARENT_READ_CHILD_WRITE\n", msg);
	signal (SIGINT, SIG_DFL);
}

int
main()
{
	int fd;
	char *m = malloc(MM_SIZE);
	char buf[1024];
	signal (SIGSEGV, SIG_IGN); /* the strcmp's should still fail */
#if defined(MAP_PRIVATE)
	fd = open(TEST_FILE, O_RDWR|O_CREAT|O_TRUNC, 0666);
	strcpy (m, "mmap magic");
	write (fd, m, 11);
	lseek (fd, 0, SEEK_SET);
	if (fd>=0)
	{
		char *p=(char *)mmap(0, MM_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
		if (p!=(char *)-1)
		{
			if (strcmp(p, m)==0)
			 	puts("HAVE_MMAP_FILE_PRIVATE_READ");
			test_child(p, "HAVE_MMAP_FILE_PRIVATE");
			strcpy (p, "mmap magic2");
			munmap (p, MM_SIZE);
			read (fd, buf, 12);
			if (strcmp(buf, "mmap magic2")!=0) /* we shouldn't be writing to the file in private mode */
				puts("HAVE_MMAP_FILE_PRIVATE_WRITE");
		}
		close (fd);
	}
#endif
#if defined(MAP_SHARED) /* we should fork off another process to test the sharing */
	fd = open(TEST_FILE, O_RDWR|O_CREAT|O_TRUNC, 0666);
	strcpy (m, "mmap magic");
	write (fd, m, 11);
	lseek (fd, 0, SEEK_SET);
	if (fd>=0)
	{
		char *p=(char *)mmap(0, MM_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
		if (p!=(char *)-1)
		{
			if (strcmp(p, m)==0)
			 	puts("HAVE_MMAP_FILE_SHARED_READ");
			test_child(p, "HAVE_MMAP_FILE_SHARED");
			strcpy (p, "mmap magic2");
			munmap (p, MM_SIZE);
			read (fd, buf, 12);
			if (strcmp(buf, "mmap magic2")==0)
				puts("HAVE_MMAP_FILE_SHARED_WRITE");
		}
		close (fd);
	}
#endif
#if defined(MAP_PRIVATE)
	fd = open("/dev/zero", O_RDWR, 0666);
	if (fd>=0)
	{
		char *p=(char *)mmap(0, MM_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
		if (p!=(char *)-1)
		{
			strcpy (p, "mmap magic_dev_zero");
			if (strcmp (p, "mmap magic_dev_zero")==0)
			 	puts("HAVE_MMAP_DEV_ZERO_PRIVATE");
			test_child(p, "HAVE_MMAP_DEV_ZERO_PRIVATE");
			munmap (p, MM_SIZE);
		}
		close (fd);
	}
#endif
#if defined(MAP_PRIVATE)
	fd = open("/dev/zero", O_RDWR, 0666);
	if (fd>=0)
	{
		char *p=(char *)mmap(0, MM_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
		if (p!=(char *)-1)
		{
			strcpy (p, "mmap magic_dev_zero_shared");
			if (strcmp (p, "mmap magic_dev_zero_shared")==0)
			 	puts("HAVE_MMAP_DEV_ZERO_SHARED");
			test_child(p, "HAVE_MMAP_DEV_ZERO_SHARED");
			munmap (p, MM_SIZE);
		}
		close (fd);
	}
#endif
#if defined(MAP_ANONYMOUS) && !defined(MAP_ANON)
#define MAP_ANON MAP_ANONYMOUS
#endif
#ifdef MAP_ANON
	{
		char *p=(char *)mmap(0, MM_SIZE, PROT_READ | PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0);
		if (p!=(char *)-1)
		{
			strcpy (p, "mmap magic_anon");
			if (strcmp(p, "mmap magic_anon")==0)
			 	puts("HAVE_MMAP_ANON_PRIVATE");
			test_child(p, "HAVE_MMAP_ANON_PRIVATE");
			munmap (p, MM_SIZE);
		}
	}
#endif
#if defined(MAP_ANON) && defined(MAP_SHARED) /* we should fork off another process to test the sharing */
	{
		char *p=(char *)mmap(0, MM_SIZE, PROT_READ | PROT_WRITE, MAP_ANON|MAP_SHARED, -1, 0);
		if (p!=(char *)-1)
		{
			strcpy (p, "mmap magic_shared_anon");
			if (strcmp(p, "mmap magic_shared_anon")==0)
			 	puts("HAVE_MMAP_ANON_SHARED");
			test_child(p, "HAVE_MMAP_ANON_SHARED");
			munmap (p, MM_SIZE);
		}
	}
#endif
	unlink(TEST_FILE);
	exit (0);
}
- -- 
"Of all tyrannies a tyranny sincerely  exercised for the good of its victims  
 may be the most  oppressive.  It may be better to live under  robber barons  
 than  under  omnipotent  moral busybodies,  The robber baron's  cruelty may  
 sometimes sleep,  his cupidity may at some point be satiated; but those who  
 torment us for own good  will torment us  without end,  for they do so with 
 the approval of their own conscience."    -   C.S. Lewis, _God in the Dock_ 
+---------------------+--------------------+----------------------------------+
|Julian Assange RSO   | PO Box 2031 BARKER | Secret Analytic Guy Union        |
|proff@suburbia.net   | VIC 3122 AUSTRALIA | finger for PGP key hash ID =     |
|proff@gnu.ai.mit.edu | FAX +61-3-98199066 | 0619737CCC143F6DEA73E27378933690 |
+---------------------+--------------------+----------------------------------+

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