From: "Reshetova, Elena" <elena.reshetova@intel.com>
To: David Laight <David.Laight@ACULAB.COM>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
"linux-hams@vger.kernel.org" <linux-hams@vger.kernel.org>,
"linux-ppp@vger.kernel.org" <linux-ppp@vger.kernel.org>,
"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
"ganeshgr@chelsio.com" <ganeshgr@chelsio.com>,
"nbd@openwrt.org" <nbd@openwrt.org>,
"blogic@openwrt.org" <blogic@openwrt.org>,
"matthias.bgg@gmail.com" <matthias.bgg@gmail.com>,
"yishaih@mellanox.com" <yishaih@mellanox.com>,
"saeedm@mellanox.com" <saeedm@mellanox.com>,
"matanb@mellanox.com" <matanb@mellanox.com>,
"leonro@mellanox.com" <leonro@mellanox.com>,
"ajk@comnets.uni-bremen.de" <aj>
Subject: RE: [PATCH 06/16] drivers, net, mlx5: convert mlx5_cq.refcount from atomic_t to refcount_t
Date: Tue, 28 Mar 2017 14:00:01 +0000 [thread overview]
Message-ID: <2236FBA76BA1254E88B949DDB74E612B41C82E54@IRSMSX102.ger.corp.intel.com> (raw)
In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6DCFFBE8AF@AcuExch.aculab.com>
> From: Elena Reshetova
> > Sent: 28 March 2017 09:57
> >
> > refcount_t type and corresponding API should be
> > used instead of atomic_t when the variable is used as
> > a reference counter. This allows to avoid accidental
> > refcounter overflows that might lead to use-after-free
> > situations.
>
> I can't help feeling that you ought to find a scheme
> that will detect extra decrements and extra increments
> before the counter wraps 32 bits.
>
> If an extra reference is requested every 100us it takes 4.8 days
> for the counter to increment back to zero.
> Simple tests aren't doing to find that - but it can easily happen
> on a system that is running for several years.
So, you are proposing to try detecting this case instead of preventing overflows?
Not sure how this would look like in a generic form...
>
> David
next prev parent reply other threads:[~2017-03-28 14:00 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-28 8:56 [PATCH 00/16] Networking drivers refcount conversions Elena Reshetova
2017-03-28 8:56 ` [PATCH 01/16] drivers, net, ethernet: convert clip_entry.refcnt from atomic_t to refcount_t Elena Reshetova
2017-03-28 8:56 ` [PATCH 02/16] drivers, net, ethernet: convert mtk_eth.dma_refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 03/16] drivers, net, mlx4: convert mlx4_cq.refcount " Elena Reshetova
2017-03-28 8:56 ` [PATCH 04/16] drivers, net, mlx4: convert mlx4_qp.refcount " Elena Reshetova
2017-03-28 8:56 ` [PATCH 05/16] drivers, net, mlx4: convert mlx4_srq.refcount " Elena Reshetova
2017-03-28 8:56 ` [PATCH 06/16] drivers, net, mlx5: convert mlx5_cq.refcount " Elena Reshetova
2017-03-28 9:33 ` David Laight
2017-03-28 14:00 ` Reshetova, Elena [this message]
[not found] ` <1490691403-4016-1-git-send-email-elena.reshetova-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-03-28 8:56 ` [PATCH 07/16] drivers, net, mlx5: convert fs_node.refcount " Elena Reshetova
2017-03-28 8:56 ` [PATCH 08/16] drivers, net, hamradio: convert sixpack.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 09/16] drivers, net: convert masces_rx_sa.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 10/16] drivers, net: convert masces_rx_sc.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 11/16] drivers, net: convert masces_tx_sa.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 12/16] drivers, net, ppp: convert asyncppp.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 13/16] drivers, net, ppp: convert ppp_file.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 14/16] drivers, net, ppp: convert syncppp.refcnt " Elena Reshetova
2017-03-28 8:56 ` [PATCH 15/16] drivers, net, intersil: convert hostap_cmd_queue.usecnt " Elena Reshetova
[not found] ` <1490691403-4016-16-git-send-email-elena.reshetova-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-04-03 11:38 ` [PATCH 15/16] drivers, net, intersil: convert hostap_cmd_queue.usecnt from atomic_t to refcount_ Kalle Valo
2017-05-22 15:24 ` [15/16] hostap: convert hostap_cmd_queue.usecnt from atomic_t to refcount_t Kalle Valo
2017-03-28 8:56 ` [PATCH 16/16] drivers, net, intersil: convert request_context.refcount " Elena Reshetova
2017-04-03 11:41 ` [PATCH 16/16] drivers, net, intersil: convert request_context.refcount from atomic_t to refcount Kalle Valo
2017-04-04 10:07 ` Reshetova, Elena
2017-04-05 10:33 ` Kalle Valo
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