From: Christoph Hellwig <hch@lst.de>
To: Chaitanya Kulkarni <chaitanyak@nvidia.com>
Cc: Sagi Grimberg <sagi@grimberg.me>, Christoph Hellwig <hch@lst.de>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
Keith Busch <kbusch@kernel.org>,
Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
Hannes Reinecke <hare@suse.de>,
Yanjun Zhang <zhangyanjun@cestc.cn>
Subject: Re: [PATCH v3] nvme-tcp: fix a possible UAF when failing to allocate an io queue
Date: Wed, 22 Mar 2023 09:15:39 +0100 [thread overview]
Message-ID: <20230322081539.GA22139@lst.de> (raw)
In-Reply-To: <915f65a2-226c-ae20-0575-e20120e72a72@nvidia.com>
On Tue, Mar 21, 2023 at 05:12:57AM +0000, Chaitanya Kulkarni wrote:
> > +#ifdef CONFIG_NET_RX_BUSY_POLL
> > + queue->sock->sk->sk_ll_usec = 1;
> > +#endif
> > + write_unlock_bh(&queue->sock->sk->sk_callback_lock);
> > +}
> > +
>
> since its is not in the fast path, is there a particular reason not
> to use following ?
>
> if (IS_ENABLED(CONFIG_NET_RX_BUSY_POLL)
> queue->sock->sk->sk_ll_usec = 1;
That won't compile, as the sk_ll_usec is not defined without
CONFIG_NET_RX_BUSY_POLL.
Note that this has nothing to do with a fast path - for cases where
IS_ENABLED works there is no performance benefit to use an ifdef
given that IS_ENABLED is ѕpecifically designed to lead to compiler
dead code elimination.
next prev parent reply other threads:[~2023-03-22 8:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-20 13:33 [PATCH v3] nvme-tcp: fix a possible UAF when failing to allocate an io queue Sagi Grimberg
2023-03-21 5:12 ` Chaitanya Kulkarni
2023-03-22 8:15 ` Christoph Hellwig [this message]
2023-03-22 8:18 ` Sagi Grimberg
2023-03-22 8:20 ` Christoph Hellwig
2023-03-22 8:24 ` Sagi Grimberg
2023-03-22 8:27 ` Christoph Hellwig
2023-03-22 13:06 ` Sagi Grimberg
-- strict thread matches above, loose matches on Subject: below --
2023-03-29 6:23 zhangyanjun
2023-03-30 2:27 ` Christoph Hellwig
2023-03-30 2:14 zhangyanjun
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