netdev - Re: locking in net_device

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: <20120321122503.25838566@nehalam.linuxnetplumber.net>
Date:	Wed, 21 Mar 2012 12:25:03 -0700
From:	Stephen Hemminger <shemminger@...tta.com>
To:	Jeff Haran <jharan@...emobile.com>
Cc:	"netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: Re: locking in net_device_ops callbacks

On Wed, 21 Mar 2012 18:59:30 +0000
Jeff Haran <jharan@...emobile.com> wrote:

> Hi,
> 
> I had posted the below to the kernelnewbies email list and never got a response. I am hoping somebody on this list could provide some feedback.
> 
> Just to be clear, it's not the issue of copying the MAC address that I am asking about. That's just an example.
> 
> What I am trying to understand is, what mechanisms generally are at play to serialize access to struct net_device private data that is accessed in both process and softirq contexts? Explicit locking "seems" to be mostly absent from the driver sources I've inspected so I can't help but believe I am missing something fundamental here.

Look at rtnl_lock() in net/core/rtnetlink.c; this is global mutex against
all changes to network device state.

--
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