From mboxrd@z Thu Jan  1 00:00:00 1970
From: Geoff Keating <geoffk@ozemail.com.au>
To: drepper@cygnus.com
Cc: kukuk@suse.de, libc-hacker@sourceware.cygnus.com
Subject: Re: interesting change
Date: Sat, 31 Jul 1999 20:42:00 -0000
Message-id: <199907310741.RAA00956@gluttony.geoffk.wattle.id.au>
References: <m3aesd2ybu.fsf@localhost.localnet> <19990731080219.A6381@Wotan.suse.de> <m31zdp2vne.fsf@localhost.localnet> <19990731085101.A9440@Wotan.suse.de> <m3lnbx1f5l.fsf@localhost.localnet>
X-SW-Source: 1999-07/msg00131.html

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> Cc: libc-hacker@sourceware.cygnus.com
> Reply-To: drepper@cygnus.com (Ulrich Drepper)
> From: Ulrich Drepper <drepper@cygnus.com>
> Date: 30 Jul 1999 23:56:06 -0700
> 
> Thorsten Kukuk <kukuk@suse.de> writes:
> 
> > 1. One of our malloc function was called before the crash in
> >   a way that __libc_pagesize is not set the first time.
> 
> The value is set in a constructor which runs before any application
> code.  Except if the application somehow inluences the constructors
> which does not only break mallo.c

It's possible that ld.so has started calling the wrong malloc() again.

There's a short window when ld.so musn't call malloc(), because it
will get the application's malloc before it has run the constructors.

The easiest way to find this is to have a small application:

void *malloc(size_t m)
{
  write (STDOUT_FILENO, "malloc called\n", 14);
  return 0;
}

void _start(void)
{ 
  write (STDOUT_FILENO, "ok to call malloc after this\n", 29);
  _exit(0);
}

-- 
Geoffrey Keating <geoffk@cygnus.com>