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  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]
Date:	Wed, 13 Aug 2008 07:31:40 +0000
From:	Jarek Poplawski <>
To:	David Miller <>
Subject: Re: [PATCH] pkt_sched: Destroy gen estimators under rtnl_lock().

On Wed, Aug 13, 2008 at 06:53:02AM +0000, Jarek Poplawski wrote:
> Thats why I still think a "common" RCU with rcu_dereference() (from
> dev_queue pointer)

I hope nobody read this literally: I mean using dev_queue pointer
for dereferencing Qdisc pointer...

> in net_tx_action() should be enough: after
> synchronize_rcu() in dev_deactivate() we are sure any qdisc_run(),
> from dev_queue_xmit() or net_tx_action() can only see and lock
> noop_qdisc. Any activities on qdisc_sleeping can't happen so no
> need to wait for this. There could be some skbs enqueued just before
> synchronize, and they could be ->reset() and ->destroy() just after,
> even without rcu_call().

BTW, this all is easy to verify: simply adding debugging waiting loops
with checking the state of qdisc_sleeping after synchronize_rcu.

Jarek P. 
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists