netdev - Re: [Patch net-next v5 3/3] igmp: convert RTNL lock to a spinlock

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: <1371284768.3252.151.camel@edumazet-glaptop>
Date:	Sat, 15 Jun 2013 01:26:08 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Cong Wang <amwang@...hat.com>
Cc:	netdev@...r.kernel.org,
	Stephen Hemminger <stephen@...workplumber.org>,
	"David S. Miller" <davem@...emloft.net>
Subject: Re: [Patch net-next v5 3/3] igmp: convert RTNL lock to a spinlock

On Sat, 2013-06-15 at 16:12 +0800, Cong Wang wrote:

> I _did_ try to replace spinlock with mutex, but apparently mutex_lock()
> can't be called with rcu_read_lock() held, which is the case in
> ip_mc_drop_socket().
> 

If you hold a mutex, there is no need for rcu_read_lock() at all.

Nobody can change the lists while you are the owner.

We already have nice helpers, lockdep enabled.

check rtnl_dereference() uses


--
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