From: Patrick McHardy <kaber@trash.net>
To: David Miller <davem@davemloft.net>
Cc: shemminger@linux-foundation.org, netdev@vger.kernel.org
Subject: Re: [IPV4 3/5] fib_trie: dump doesnt use RCU
Date: Thu, 24 Jan 2008 07:47:39 +0100 [thread overview]
Message-ID: <4798348B.4080300@trash.net> (raw)
In-Reply-To: <20080123.224337.80401207.davem@davemloft.net>
David Miller wrote:
> From: Patrick McHardy <kaber@trash.net>
> Date: Thu, 24 Jan 2008 07:41:08 +0100
>
>
>> David Miller wrote:
>>
>>> and nothing in that code path retakes the RTNL semaphore.
>>>
>> Actually we're always holding the rtnl during dumps, nlk->cb_mutex points
>> to rtnl_mutex in case of rtnetlink. It used to be held only during the first
>> ->dump invocation and not on continuations, but I changed this a few
>> versions ago.
>>
>
> My bad. Thanks for the correction Patrick.
>
> But continuations can occur on subsequent recvmsg() calls,
> does it return to userspace with the mutex held? If so
> I'm pretty sure that's not allowed.
>
No, the mutex is dropped between different ->dump invocations.
next prev parent reply other threads:[~2008-01-24 6:47 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20080123224844.610730277@linux-foundation.org>
2008-01-23 22:48 ` [IPV4 1/5] fib_trie: more whitespace cleanup Stephen Hemminger
2008-01-24 4:37 ` David Miller
2008-01-23 22:48 ` [IPV4 2/5] fib_trie: remove unneeded NULL check Stephen Hemminger
2008-01-24 4:38 ` David Miller
2008-01-23 22:48 ` [IPV4 3/5] fib_trie: dump doesnt use RCU Stephen Hemminger
2008-01-24 4:50 ` David Miller
2008-01-24 6:41 ` Patrick McHardy
2008-01-24 6:43 ` David Miller
2008-01-24 6:47 ` Patrick McHardy [this message]
2008-01-24 7:26 ` David Miller
2008-01-24 6:45 ` Stephen Hemminger
2008-01-24 7:27 ` David Miller
2008-01-24 21:51 ` [PATCH] fib_trie: rescan if key is lost during dump Stephen Hemminger
2008-01-25 8:23 ` Jarek Poplawski
2008-01-25 16:13 ` Stephen Hemminger
2008-01-25 19:01 ` Jarek Poplawski
2008-02-01 0:45 ` David Miller
2008-01-23 22:48 ` [IPV4 4/5] fib_trie: version 0.410 Stephen Hemminger
2008-01-24 4:50 ` David Miller
2008-01-23 22:48 ` [IPV4 5/5] fib_semantics: sparse warnings Stephen Hemminger
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