From: Ding Tianhong <dingtianhong@huawei•com>
To: Cong Wang <amwang@redhat•com>, <netdev@vger•kernel.org>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6•org>,
"David S. Miller" <davem@davemloft•net>
Subject: Re: [Patch net] ipv6,mcast: always hold idev->lock before mca_lock
Date: Fri, 28 Jun 2013 14:26:07 +0800 [thread overview]
Message-ID: <51CD2C7F.5060200@huawei.com> (raw)
In-Reply-To: <20130627034204.GB18553@order.stressinduktion.org>
On 2013/6/27 11:42, Hannes Frederic Sowa wrote:
> On Thu, Jun 27, 2013 at 11:09:44AM +0800, Cong Wang wrote:
>> On Thu, 2013-06-27 at 00:58 +0200, Hannes Frederic Sowa wrote:
>>> I do confirm that if this last hunk is applied the idev->addr_list
>>> traversal
>>> is safe.
>>>
>>> Please let me know if no one is working on this, I would rebase it
>>> then.
>>
>> I will rebase my patch on latest net-next. I am assuming this patch
>> looks good to you...
>
> Yes, I am fine with the apporach you took. Perhaps you could describe
> why the non-idev-locked call to__ipv6_get_lladdr-call is ok in that place.
>
> Thanks a lot,
>
> Hannes
>
>
>
I think the problem is clear:
mld_send_report(...){
read_lock_bh(&idev->lock);
add_grec（...）
read_unlock_bh(&idev->lock);
}
--->add_grec(...){
add_grhead(...)
}
--->add_grhead(...){
mld_newpack(...)
}
--->mld_newpack(...){
ipv6_get_lladdr(...)
}
--__ipv6_get_lladdr(..) (after the patch, so it is protect by the idev->lock)
compare
--->ipv6_get_lladdr(...){ (before the patch)
read_lock_bh(&idev->lock);
...
read_unlock_bh(&idev->lock);
}
so i think it is clear to describe the reason.
next prev parent reply other threads:[~2013-06-28 6:26 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-08 7:41 [Patch net] ipv6,mcast: always hold idev->lock before mca_lock Cong Wang
2013-05-08 9:47 ` dingtianhong
2013-05-08 20:16 ` David Miller
2013-05-11 23:11 ` David Miller
2013-05-27 6:52 ` dingtianhong
2013-06-06 2:35 ` Cong Wang
2013-05-21 7:01 ` dingtianhong
2013-05-21 10:10 ` Hannes Frederic Sowa
2013-06-26 22:58 ` Hannes Frederic Sowa
2013-06-27 3:09 ` Cong Wang
2013-06-27 3:42 ` Hannes Frederic Sowa
2013-06-28 6:26 ` Ding Tianhong [this message]
2013-06-28 10:46 ` Hannes Frederic Sowa
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