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From: David Ahern <dsahern@kernel.org>
To: Niels Dossche <dossche.niels@gmail.com>,
	Paolo Abeni <pabeni@redhat.com>,
	netdev@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
	Jakub Kicinski <kuba@kernel.org>
Subject: Re: [PATCH v2] ipv6: acquire write lock for addr_list in dev_forward_change
Date: Mon, 21 Mar 2022 09:42:14 -0600	[thread overview]
Message-ID: <5bda97a3-6efc-4ce2-859a-be44f3c2345e@kernel.org> (raw)
In-Reply-To: <8b90b4a6-a906-0f46-bb87-0ec51c9c89fe@gmail.com>

On 3/19/22 7:17 AM, Niels Dossche wrote:
> I have an additional question about the locks on the addr_list actually.
> In addrconf_ifdown, there's a loop on addr_list within a write lock in idev->lock
>> list_for_each_entry_safe(ifa, tmp, &idev->addr_list, if_list)
> The loop body unlocks the idev->lock and reacquires it later. I assume because of the lock dependency on ifa->lock and the calls that acquire the mc_lock? Shouldn't that list iteration also be protected during the whole iteration?
> 


That loop needs to be improved as well. Locking in ipv6 code is a bit
hairy.

  reply	other threads:[~2022-03-21 15:42 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-17 15:56 [PATCH v2] ipv6: acquire write lock for addr_list in dev_forward_change Niels Dossche
2022-03-18  9:13 ` Paolo Abeni
2022-03-18 12:48   ` Paolo Abeni
2022-03-18 15:42     ` Paolo Abeni
2022-03-18 15:45       ` Niels Dossche
2022-03-18 16:50         ` Paolo Abeni
2022-03-19 13:17           ` Niels Dossche
2022-03-21 15:42             ` David Ahern [this message]
2022-03-21 18:15               ` Paolo Abeni
2022-03-21 18:28                 ` Niels Dossche

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