Date: Wed, 11 Aug 1999 10:30:34 -0700 From: David Greenman <dg@root.com> To: Oleg Derevenetz <oleg@oleg.sani-c.vrn.ru> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: mmap bug Message-ID: <199908111730.KAA26611@implode.root.com> In-Reply-To: Your message of "Wed, 11 Aug 1999 20:48:08 %2B0400." <199908111648.UAA01527@oleg.sani-c.vrn.ru>
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This report seems to be severely lacking in details. First, I don't understand why it is called "mmap" since it doesn't do an mmap and the "addr" that is being frobbed with isn't even initialized. Second, I get a core dump when I run it on a -stable machine: [speedy:tmp9] mmap unlink files? NO mmaping 10485760 byte region on file 0 Segmentation fault (core dumped) ...which is exactly what I'd expect when dealing with a bogus pointer. You didn't specify what version of FreeBSD you saw a hang and didn't provide any details of the hang. Please provide more information so that we can help you. Thanks. -DG David Greenman Co-founder/Principal Architect, The FreeBSD Project - http://www.freebsd.org Creator of high-performance Internet servers - http://www.terasolutions.com >This small program, running as 'mmap', not 'mmap -u', can hang my machine. >Is this a known bug in FreeBSD's kernel, or it is my fantasy ? >Thank you for answer. > >#include <stdio.h> >#include <stdlib.h> >#include <sys/types.h> >#include <sys/mman.h> >#include <unistd.h> >#include <fcntl.h> >#include <errno.h> > >main(int argc, char *argv[]) >{ > int fd; > int i; > int len=1024*1024*10; /*ie 10Mbytes*/ > caddr_t addr; > char ttt[80]; > int bunlink = 0; > > if ( argc > 1 && strcmp(argv[1], "-u") == 0 ) { > bunlink = 1; > } > printf("unlink files? %s\n", bunlink ? "YES" : "NO"); > > for (i=0;;i++) > { > sprintf (ttt,"%d",i); > printf("mmaping %ld byte region on file %s\n", len, ttt); > fd=open(ttt,O_CREAT|O_RDWR,0666); > if (fd<0) > { > printf("mmap error %ld",errno); > exit(1); > } > memset(addr,'x',len); > if ( munmap(addr, len) != 0 ) { > fprintf(stderr, "munmap failed\n"); > exit(EXIT_FAILURE); > } > close(fd); > if ( bunlink ) unlink(ttt); > } >} > > >To Unsubscribe: send mail to majordomo@FreeBSD.org >with "unsubscribe freebsd-hackers" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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