From: David Stockton <stockton AT bcm DOT tmc DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Help interpreting a stack trace
Date: Wed, 23 Apr 1997 09:02:49 -0500
Organization: Baylor College of Medicine, Houston, Tx
Lines: 53
Message-ID: <335E1689.766D@bcm.tmc.edu>
NNTP-Posting-Host: ginger.imgen.bcm.tmc.edu
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Precedence: bulk


I am working on a library of routines and a small test program
(about 30 lines; the call a routine, print a message type)
dies with the following stack trace.  Since it dies in a standard
library routine I was not sure how to track it down.  Note also
that if I change the declaration of selects timeout argument 
to static the GPF goes away.  Am I running out of stack space?
Any help would be much appreciated.
                                     Thanks,
                                         David
The calling code looks like this...

 struct timeval          timeout;
 fd_set                  dsmask;
 int                     n, fd;
 <snip>
 timeout.tv_sec = 1;
 timeout.tv_usec = 0;
 FD_ZERO( &dsmask );
 FD_SET( fd, &dsmask );
 printf( "Calling select( %d, %#x, NULL, NULL, %#x )\n", fd+1,
         (unsigned int) &dsmask, (unsigned int) &timeout );
 fflush( stdout );
 n = select( fd+1, &dsmask,(fd_set *) NULL, (fd_set *) NULL,
         &timeout );

And here is what gets written to the screen (after symify)...

Calling select( 8, 0x58b98, NULL, NULL, 0x58b90 )
Exiting due to signal SIGSEGV
General Protection Fault at eip=00010002
eax=00000000 ebx=000176b4 ecx=0000ff5f edx=00010054 esi=000007cd
edi=0000ff10
ebp=00057dc0 esp=00057dc0 program=C:\OBJ\TEST3.EXE
cs: sel=00f7  base=82ceb000  limit=0006ffff
ds: sel=00ff  base=82ceb000  limit=0006ffff
es: sel=00ff  base=82ceb000  limit=0006ffff
fs: sel=011f  base=82d5c000  limit=00010000
gs: sel=010f  base=00000000  limit=ffffffff
ss: sel=00ff  base=82ceb000  limit=0006ffff

Call frame traceback EIPs:
  0x00010002   ___crlf2nl+290
  0x000100bc   ___crlf2nl+476
  0x00010d86   ___crlf2nl+3750
  0x00010e82   ___tzset+222
  0x00010dc0   ___tzset+28
  0x00010eae   ___tzset+266
  0x000114a3   _ctime+551
  0x0001161d   _ctime+929
  0x00011732   _mktime+18
  0x0000f5a8   ___gettimeofday+168
  0x0000a64e   _select+114
 bash$ symify obj/test3.exe