public inbox for cygwin@cygwin.com
 help / color / mirror / Atom feed
* similar crash in mmap for 1.5.3-1
@ 2003-09-08 22:33 John Joganic
  2003-09-08 23:42 ` Christopher Faylor
  2003-09-09  8:28 ` similar crash in mmap for 1.5.3-1 Corinna Vinschen
  0 siblings, 2 replies; 12+ messages in thread
From: John Joganic @ 2003-09-08 22:33 UTC (permalink / raw)
  To: cygwin

Previous posts described a bug in mmap called via malloc. I am seeing a 
bug in mmap itself.  The following test does not map large amounts of 
memory, nor does it leak.  It crashes however, after 4193 (0x1061) 
iterations every time.  Like the malloc crash, the call stack references 
strdup, and in this case calloc as well.  On a Linux box, this program 
runs to completion without a hitch.

Thanks!

-John

fail.c:

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

int main(int argc, char **argv)
{
        int i, fd;
        void *p;
        char buf[1024] = { 0 };

        fd = open("test.dat",O_CREAT|O_RDWR,0666);
        if (fd < 0) { perror("failed to open"); exit(1); }
        write(fd,buf,1024);

        for (i=0; i<10000; ++i)
        {
                fprintf(stderr,"%d ",i);
                p = mmap(NULL,1024,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);
                if (!p) { perror("failed mmap"); exit(1); }
                fprintf(stderr,"=> %p\n",p);
                munmap(p,1024);
        }

        printf("success\n");
        close(fd);
        return 0;
}

The result is:

...
4186 => 0x3f0000
4187 => 0x3f0000
4188 => 0x3f0000
4189 => 0x3f0000
4190 => 0x3f0000
4191 => 0x3f0000
4192 => 0x3f0000
4193       4 [main] fail 3024 cmalloc: cmalloc returned NULL

Program received signal SIGSEGV, Segmentation fault.
0x6103f1d9 in strdup () from /usr/bin/cygwin1.dll
(gdb) bt
#0  0x6103f1d9 in strdup () from /usr/bin/cygwin1.dll
#1  0x6103fcc2 in mmap64 () from /usr/bin/cygwin1.dll
#2  0x004011d6 in main ()
(gdb)



--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

^ permalink raw reply	[flat|nested] 12+ messages in thread
end of thread, other threads:[~2003-09-10 21:35 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2003-09-08 22:33 similar crash in mmap for 1.5.3-1 John Joganic
2003-09-08 23:42 ` Christopher Faylor
2003-09-09  8:43   ` cygwin1.dll - debug version (RE: similar crash in mmap for 1.5.3-1) Hannu E K Nevalainen (garbage mail)
2003-09-09 17:26     ` Christopher Faylor
2003-09-10 11:25       ` Hannu E K Nevalainen (garbage mail)
2003-09-10 15:32         ` Christopher Faylor
2003-09-10 15:40           ` Igor Pechtchanski
2003-09-10 16:00             ` Christopher Faylor
2003-09-10 20:27               ` Hannu E K Nevalainen (garbage mail)
2003-09-10 21:01                 ` Christopher Faylor
2003-09-10 21:35                   ` Hannu E K Nevalainen (garbage mail)
2003-09-09  8:28 ` similar crash in mmap for 1.5.3-1 Corinna Vinschen

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).