From: Krzysztof Halasa <khc@pm.waw.pl>
To: Wang Chen <wangchen@cn.fujitsu.com>
Cc: Jeff Garzik <jgarzik@pobox.com>,
netdev@vger.kernel.org, "David S. Miller" <davem@davemloft.net>
Subject: Re: [PATCH] HDLC driver: use unregister_netdev instead of unregister_netdevice
Date: Fri, 14 Dec 2007 22:28:07 +0100 [thread overview]
Message-ID: <m3ve71t194.fsf@maximus.localdomain> (raw)
In-Reply-To: <475F490C.2020305@cn.fujitsu.com> (Wang Chen's message of "Wed, 12 Dec 2007 10:35:56 +0800")
Wang Chen <wangchen@cn.fujitsu.com> writes:
> [PATCH] HDLC driver: use unregister_netdev instead of unregister_netdevice
>
> Since the caller and the upper caller doesn't hod the rtnl semaphore.
> We should use unregister_netdev instead of unregister_netdevice.
NAK, not-a-bug. The caller actually holds rtnl, it goes through
the netdev core ioctl dispatcher:
(unregister_netdevice+0x0/0x24) from (fr_ioctl+0x688/0x75c)
/* fr_del_pvc() and fr_add_pvc() optimized out by gcc */
(fr_ioctl+0x0/0x75c) from (hdlc_ioctl+0x4c/0x8c)
(hdlc_ioctl+0x0/0x8c) from (hss_ioctl+0x3c/0x324)
(hss_ioctl+0x0/0x324) from (dev_ifsioc+0x428/0x4e8)
(dev_ifsioc+0x0/0x4e8) from (dev_ioctl+0x5d8/0x664)
(dev_ioctl+0x0/0x664) from (sock_ioctl+0x90/0x254)
(sock_ioctl+0x0/0x254) from (do_ioctl+0x34/0x78)
(do_ioctl+0x0/0x78) from (vfs_ioctl+0x78/0x2a8)
(vfs_ioctl+0x0/0x2a8) from (sys_ioctl+0x40/0x64)
(sys_ioctl+0x0/0x64) from (ret_fast_syscall+0x0/0x2c)
The patch would make it deadlock.
Please note that sister fr_add_pvc() uses register_netdevice().
The same applies to fr_destroy().
--
Krzysztof Halasa
next prev parent reply other threads:[~2007-12-14 21:28 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-12 2:35 [PATCH] HDLC driver: use unregister_netdev instead of unregister_netdevice Wang Chen
2007-12-12 18:46 ` David Miller
2007-12-13 3:13 ` Herbert Xu
2007-12-13 3:22 ` David Miller
2007-12-14 21:28 ` Krzysztof Halasa [this message]
2007-12-14 21:36 ` David Miller
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