netdev - Re: Putting for discussion "__qdisc_run" bug - strange application-dependant error

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4A06834A.1040307@gmail.com>
Date:	Sun, 10 May 2009 09:33:30 +0200
From:	Jarek Poplawski <jarkao2@...il.com>
To:	Panadero Pizza <panadero_pizza@...oo.es>
CC:	netdev@...r.kernel.org
Subject: Re: Putting for discussion "__qdisc_run" bug - strange application-dependant
 error

Panadero Pizza wrote, On 05/09/2009 09:55 PM:

> Hello netdev group,
> 
> I would like to put for discussion, if a bug in the __qdsic_run function could explain the problem I have described in my post "Kernel networking problem (>=2.6.24.7)" two days ago.
> 
> "__qdisc_run" is the last common function in the kernel traces I receive for the kernels:
> 
> 2.6.24.7
> 2.6.27.12
> 
> with a multi-threaded software, using fputc, putc, puts - calls, mixed with fflush()-calls on a remote file, opened on a cifs-handle. (Errors occur extremely seldom, although the software is running for hours - day after day)
> 
> I don't receive the error with other standard software (e.g. "dd"), writing to a file on the same cifs-handle/session and more interesting:
> The error does not occur with the afore-mentioned multi-threaded program (or any other software), using a
> 
> 2.6.16.62
> 
> kernel.
> 
> I have found that from 2.6.24.x on, the __qdisc_run function has been made preemptible and this feature has been enabled for the realization of the afore-said 2.6.24.7 and 2.6.27.12 kernels.
> 
> Though 2.6.16.62 solves my problem, I am offering participation in finding a solution for this (which should be fixed, if it is a kernel bug).
> 


Since you're suggesting the specific patch has broken this for you, could
you simply write if 2.6.24.4 (or 2.6.24.7 with "NET: Add preemption point
in qdisc_run" patch reverted) also solves your problem?

Btw., you've admitted the stack could be a problem; did you try to enable
any kernel debugging for this?

Cheers,
Jarek P.

PS: continuing the discussion within one thread and limiting line width
would make it easier to track this report.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html