netdev - Re: [PATCH] pkt_sched: Fix lockdep warning on est_tree_lock in gen

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: <20100902.132248.229742285.davem@davemloft.net>
Date:	Thu, 02 Sep 2010 13:22:48 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	jarkao2@...il.com
Cc:	eric.dumazet@...il.com, netdev@...r.kernel.org
Subject: Re: [PATCH] pkt_sched: Fix lockdep warning on est_tree_lock in
 gen_estimator

From: Jarek Poplawski <jarkao2@...il.com>
Date: Thu, 2 Sep 2010 22:12:58 +0200

> This patch fixes a lockdep warning:
> 
> [  516.287584] =========================================================
> [  516.288386] [ INFO: possible irq lock inversion dependency detected ]
> [  516.288386] 2.6.35b #7
> [  516.288386] ---------------------------------------------------------
> [  516.288386] swapper/0 just changed the state of lock:
> [  516.288386]  (&qdisc_tx_lock){+.-...}, at: [<c12eacda>] est_timer+0x62/0x1b4
> [  516.288386] but this lock took another, SOFTIRQ-unsafe lock in the past:
> [  516.288386]  (est_tree_lock){+.+...}
> [  516.288386] 
> [  516.288386] and interrupts could create inverse lock ordering between them.
> ...
> 
> So, est_tree_lock needs BH protection because it's taken by
> qdisc_tx_lock, which is used both in BH and process contexts.
> (Full warning with this patch at netdev, 02 Sep 2010.)
> 
> Fixes commit: ae638c47dc040b8def16d05dc6acdd527628f231
> 
> Signed-off-by: Jarek Poplawski <jarkao2@...il.com>

Applied, thanks Jarek.

Eric, please make an effort to run with lockdep enabled when making
locking changes, just for fun :-)
--
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