From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krzysztof Halasa Subject: Re: [PATCH] HDLC driver: use unregister_netdev instead of unregister_netdevice Date: Fri, 14 Dec 2007 22:28:07 +0100 Message-ID: References: <475F490C.2020305@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jeff Garzik , netdev@vger.kernel.org, "David S. Miller" To: Wang Chen Return-path: Received: from khc.piap.pl ([195.187.100.11]:37756 "EHLO khc.piap.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753087AbXLNV2L (ORCPT ); Fri, 14 Dec 2007 16:28:11 -0500 In-Reply-To: <475F490C.2020305@cn.fujitsu.com> (Wang Chen's message of "Wed, 12 Dec 2007 10:35:56 +0800") Sender: netdev-owner@vger.kernel.org List-ID: Wang Chen 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