[Date Prev][Date Next]
Re: (ITS#7723) slapd crashes on multi core machines if a search request is *immediately* followed by an unbind
- To: openldap-its@OpenLDAP.org
- Subject: Re: (ITS#7723) slapd crashes on multi core machines if a search request is *immediately* followed by an unbind
- From: firstname.lastname@example.org
- Date: Mon, 4 Nov 2013 14:11:53 GMT
- Auto-submitted: auto-generated (OpenLDAP-ITS)
> On 10/15/2013 01:10 PM, email@example.com wrote:
>> It is not the client loop that is multithreading but the ldap server.
>> And it is not a misuse of the API but a problem that may be raised by day t=
>> o day network problems.
>> I've boiled down the problem to a few simple configurations that work (or b=
>> etter, fail ;-) with both 2.4.23 and 2.4.36. A tgz file containing a setup =
>> with start script and testclient is attached. It should be sufficient to re=
>> produce the fault.
>> The problem occurs only if we use session variable substitution in the rwm =
>> overlay, and only if a search is *immediately* (e.g. caused by network loss=
>> and client timeout) followed by an unbind.
> I modified the reproducer a bit (the start script) and find out a few things.
> You can find the reproducer I'm using at .
> Valgrind's helgrind shows some lock problems in the rwm overlay and also in
> back-ldap and connection.c. After correcting those the issue seems to be gone.
> You can find helgrind logs at  (before the fix) and  (after).
> Also, ElectricFence reveals some problems , which I didn't fix yet.
> A fix attempt can be found at . I'm not sure if that is a correct fix, or it
> just masked the real issue. But I didn't to manage to reproduce the problem
> after applying it.
I already explained the problem. The other issues you identified are not
relevant, and your patch is not correct. Reread Followup #4 of this ITS.
-- Howard Chu
CTO, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/