netdev - Re: [PATCH net-next 1/4] scsi_tcp: block BH in TCP callbacks

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: <1463592565.18194.137.camel@edumazet-glaptop3.roam.corp.google.com>
Date:	Wed, 18 May 2016 10:29:25 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Mike Christie <michaelc@...wisc.edu>
Cc:	Eric Dumazet <edumazet@...gle.com>,
	"David S . Miller" <davem@...emloft.net>,
	netdev <netdev@...r.kernel.org>,
	Venkatesh Srinivas <venkateshs@...gle.com>
Subject: Re: [PATCH net-next 1/4] scsi_tcp: block BH in TCP callbacks

On Wed, 2016-05-18 at 12:21 -0500, Mike Christie wrote:

> Can I just confirm that nested bh lock calls like:
> 
> spin_lock_bh(lock1);
> spin_lock_bh(lock2);
> 
> do something
> 
> spin_unlock_bh(lock2);
> spin_unlock_bh(lock1);
> 
> is ok? It seems smatch sometimes warns about this.

It is ok.

More generally

local_bh_disable();
local_bh_disable();

..

local_bh_enable();
local_bh_enable();

is ok, we already have a lot of them.