Date: Tue, 22 Jul 2003 06:34:17 +0200
From: "Eli Zaretskii" <eliz AT elta DOT co DOT il>
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To: peter DOT claessens AT psy DOT kuleuven DOT ac DOT be
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In-reply-to: <3F1C15A3.3000302@psy.kuleuven.ac.be> (message from Peter
	Claessens on Mon, 21 Jul 2003 18:32:35 +0200)
Subject: Re: malloc/free blues
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> Date: Mon, 21 Jul 2003 18:32:35 +0200
> From: Peter Claessens <peter DOT claessens AT psy DOT kuleuven DOT ac DOT be>
> 
> C:\src\dots2002>dotread -cl
> Exiting due to signal SIGSEGV
> Page fault at eip=000bd61d, error=0006
> eax=000000af ebx=000bd724 ecx=00000010 edx=00001757 esi=000bd724 
> edi=031c17dc
> ebp=00000fbc esp=00000fbc program=<**UNKNOWN**>
> cs: sel=00a7  base=84830000  limit=03242fff
> ds: sel=00af  base=84830000  limit=03242fff
> es: sel=00af  base=84830000  limit=03242fff
> fs: sel=0087  base=00015ee0  limit=0000ffff
> gs: sel=00bf  base=00000000  limit=0010ffff
> ss: sel=03cb  invalid
> App stack: [03243000..031c3000]  Exceptn stack: [00168718..001667d8]
> 
> Call frame traceback EIPs:
>   0x000bd61d
> 
> Notice the bizarre 'program' value. This is the same run under GDB:
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x000ca7e1 in _doprnt ()
> (gdb) backtrace
> #0  0x000ca7e1 in _doprnt ()
> Cannot access memory at address 0x804

Sounds like somehow it tries to print too early, when the run-time
environment is not yet set up.  Weird.

Anyway, this probably means you should for now drop the idea of
setting DEBUG to a non-zero value.

> Do you think it would be a good or a bad idea to try the malloc_debug 
> functions in the nmalloc package that I found under the alpha 
> distribution info for djdev?

It cannot hurt to use the malloc_debug package.  Try setting the debug
level to the maximum, and see what it tells you.  Also, call the
function that checks the heap integrity in a few places, and see where
it starts complaining.

> Sorry that I channel all this material through the djgpp mailing
> list.

Nothing to be sorry about, this is the appropriate place for such
discussions.