httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Steve Hay" <Steve...@planit.com>
Subject RE: VS2010 release builds of Apache/mod_perl crash on Vista/2008/Win7
Date Fri, 04 Feb 2011 23:45:34 GMT
William A. Rowe Jr. wrote on 2011-02-04:
> On 2/4/2011 3:49 PM, Steve Hay wrote:
>> 
>> Yes, Apache, Perl and mod_perl were all brand-new builds done one
> immediately after another on the same machine, using the same VS2010
> installation for them all.
> 
> I presume by Apache you mean httpd as well as apr and apr-util, etc.

Yes, the full httpd-2.2.17-win32-src.zip built with "nmake /f Makefile.win installr".


> 
>> Also, note that the test.cpp program that I attached in my original
> post (which you've quoted the stack trace from above) is a self-
> contained standalone program, not linked to anything other than
> standard MS libraries. The functions in it are copied directly from the
> APR code with just minor renaming, macro expansion and comment removal.
> 
> Ack.
> 
>> Actually, there is one comment in httpd-
>> 2.2.17\srclib\apr\misc\win32\apr_app.c that sounds very pertinent:
>> 
>>  *   _dbg_malloc/realloc is used in place of the usual API, in order
>>  *   to convince the MSVCRT that it created these entities.  If we
>>  *   do not create them as _CRT_BLOCK entities, the crt will fault
>>  *   on an assert.  We are not worrying about the crt's locks here,
>>  *   since we are single threaded [so far].
>> 
>> It looks like the original environ[] was allocated by msvcr100.dll
> using something other than a function matching the HeapFree() function
> where the crash finally happens. The CRT code is trying to free the
> existing PATH in its environment before setting the new value coming
> from _putenv(), and it is that free that crashes, presumably because the
> APR re-processing of the environ entities didn't fool MSVCRT well enough?
> 
> That makes sense, and it should be easy to make that conditional on the
> vc version.
> Now the question is where were these allocated from in MSVCR100?  Only
> a trip through
> the crt sources will help out, there.

Indeed, but looking through the VS2010 CRT source code the environment seems to be initialized
in stdenvp.c using _calloc_crt, which should match the _free_crt call in setenv.c line 211
where it all goes wrong, so I'm confused why it's crashing. The VS2008 CRT source code looks
the same in this area too.
Mime
View raw message