From: Florian Westphal <fw@strlen.de>
To: wenxu <wenxu@ucloud.cn>
Cc: Florian Westphal <fw@strlen.de>,
pablo@netfilter.org, netfilter-devel@vger.kernel.org
Subject: Re: [PATCH nf-next] netfilter: nf_table_offload: Fix the incorrect rcu usage in nft_indr_block_get_and_ing_cmd
Date: Mon, 19 Aug 2019 12:59:25 +0200 [thread overview]
Message-ID: <20190819105925.GB2588@breakpoint.cc> (raw)
In-Reply-To: <2bde486e-dfe8-ad2b-8b77-babcad90d82e@ucloud.cn>
wenxu <wenxu@ucloud.cn> wrote:
> >> The nft_indr_block_get_and_ing_cmd is called in netdevice notify
> >> It is the incorrect rcu case, To fix it just traverse the list under
> >> the commit mutex.
> > What is an 'incorrect rcu case'?
> >
> > Please clarify, e.g. by including rcu warning/splat backtrace here.
[..]
> flow_block_ing_cmd() needs to call blocking functions while iterating block_ing_cb_list,
> nft_indr_block_get_and_ing_cmd is in the cb_list, So it should also not in rcu for blocking
> cases.
Please submit a v2 that includes this explanation in the commit message.
> >> + struct nft_ctx ctx = {
> >> + .net = dev_net(dev),
> >> + };
> > Why is this ctx needed?
> >
> >> + mutex_lock(&ctx.net->nft.commit_mutex);
> > net->nft.commit_mutex?
>
> When traverse the list, the list is protected under commit_mutex like nf_tables_netdev_event
> do in the netdevice notify callback
Yes, I see that, but why do you need nft_ctx ctx? Its confusing.
Just use
mutex_lock(&net->nft.commit_mutex);
without adding this 'ctx'.
prev parent reply other threads:[~2019-08-19 10:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-19 9:46 [PATCH nf-next] netfilter: nf_table_offload: Fix the incorrect rcu usage in nft_indr_block_get_and_ing_cmd wenxu
2019-08-19 10:21 ` Florian Westphal
2019-08-19 10:48 ` wenxu
2019-08-19 10:59 ` Florian Westphal [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190819105925.GB2588@breakpoint.cc \
--to=fw@strlen.de \
--cc=netfilter-devel@vger.kernel.org \
--cc=pablo@netfilter.org \
--cc=wenxu@ucloud.cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).