CVS 1.7.0 heap errors

Thu Jul 19 07:50:00 GMT 2007

On Jul 18 12:04, Corinna Vinschen wrote:
> On Jul 17 14:54, Brian Ford wrote:
> > > > On 2007年6月27日, Corinna Vinschen wrote:
> > > You could also try to eliminate any change from
> > > http://cygwin.com/ml/cygwin-cvs/2007-q1/msg00139.html which is not
> > > related to your problem, [...]
> > 
> > You don't have any suggestions for how to best separate the patch into
> > pieces do you?
>> Look into the ChangeLog for the patch. It can be divided into two
> different changes:
>> - Changing the cygheap->shared_prefix handling.
> [...]
>> - Changing the way the user privileges are set at process startup.
>> Affects dcrt0.cc, sec_helper.cc and security.h.
>> Stupidly glaring at this change, I'm wondering if this is the culprit.
> The change itself looks quite harmless. But the non-obvious result
> is that already very early in the process initialization functions from
> advapi32 are called. OTOH, Cygwin is load-time linked against advapi32.
> So that shouldn't have any negative effect. Hmm.

I found an actual bug in this patch. I moved the call to
set_cygwin_privileges (hProcToken); at process initialization to a point
at which hProcToken wasn't even initialized.
 *hitting myself with a big stick*
Weird that it worked at all.
This *might* be the cause of the failing heap_init. The problem is that
the calls to AdjustTokenPrivileges in set_privilege fail and
debug_printf is called (too?) early in process initialization, which in
turn results in dynamically loading user32.dll or some other Windows
DLL. If this happens before the heap is initialized, there's a chance
that the Windows DLL reserves space which is needed for the heap.
What you could do to verify this: Apply the patch from
http://cygwin.com/ml/cygwin-cvs/2007-q3/msg00039.html
to Cygwin from right after the patch from
http://cygwin.com/ml/cygwin-cvs/2007-q1/msg00139.html
and try if the heap problem still occurs.
Corinna
-- 
Corinna Vinschen Please, send mails regarding Cygwin to
Cygwin Project Co-Leader cygwin AT cygwin DOT com
Red Hat
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